/*
* Copyright © 2010 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
/** @file brw_fs.cpp
*
* This file drives the GLSL IR -> LIR translation, contains the
* optimizations on the LIR, and drives the generation of native code
* from the LIR.
*/
#include "main/macros.h"
#include "brw_eu.h"
#include "brw_fs.h"
#include "brw_nir.h"
#include "brw_vec4_gs_visitor.h"
#include "brw_cfg.h"
#include "brw_dead_control_flow.h"
#include "common/gen_debug.h"
#include "compiler/glsl_types.h"
#include "compiler/nir/nir_builder.h"
#include "program/prog_parameter.h"
using namespace brw;
static unsigned get_lowered_simd_width(const struct gen_device_info *devinfo,
const fs_inst *inst);
void
fs_inst::init(enum opcode opcode, uint8_t exec_size, const fs_reg &dst,
const fs_reg *src, unsigned sources)
{
memset(this, 0, sizeof(*this));
this->src = new fs_reg[MAX2(sources, 3)];
for (unsigned i = 0; i < sources; i++)
this->src[i] = src[i];
this->opcode = opcode;
this->dst = dst;
this->sources = sources;
this->exec_size = exec_size;
this->base_mrf = -1;
assert(dst.file != IMM && dst.file != UNIFORM);
assert(this->exec_size != 0);
this->conditional_mod = BRW_CONDITIONAL_NONE;
/* This will be the case for almost all instructions. */
switch (dst.file) {
case VGRF:
case ARF:
case FIXED_GRF:
case MRF:
case ATTR:
this->size_written = dst.component_size(exec_size);
break;
case BAD_FILE:
this->size_written = 0;
break;
case IMM:
case UNIFORM:
unreachable("Invalid destination register file");
}
this->writes_accumulator = false;
}
fs_inst::fs_inst()
{
init(BRW_OPCODE_NOP, 8, dst, NULL, 0);
}
fs_inst::fs_inst(enum opcode opcode, uint8_t exec_size)
{
init(opcode, exec_size, reg_undef, NULL, 0);
}
fs_inst::fs_inst(enum opcode opcode, uint8_t exec_size, const fs_reg &dst)
{
init(opcode, exec_size, dst, NULL, 0);
}
fs_inst::fs_inst(enum opcode opcode, uint8_t exec_size, const fs_reg &dst,
const fs_reg &src0)
{
const fs_reg src[1] = { src0 };
init(opcode, exec_size, dst, src, 1);
}
fs_inst::fs_inst(enum opcode opcode, uint8_t exec_size, const fs_reg &dst,
const fs_reg &src0, const fs_reg &src1)
{
const fs_reg src[2] = { src0, src1 };
init(opcode, exec_size, dst, src, 2);
}
fs_inst::fs_inst(enum opcode opcode, uint8_t exec_size, const fs_reg &dst,
const fs_reg &src0, const fs_reg &src1, const fs_reg &src2)
{
const fs_reg src[3] = { src0, src1, src2 };
init(opcode, exec_size, dst, src, 3);
}
fs_inst::fs_inst(enum opcode opcode, uint8_t exec_width, const fs_reg &dst,
const fs_reg src[], unsigned sources)
{
init(opcode, exec_width, dst, src, sources);
}
fs_inst::fs_inst(const fs_inst &that)
{
memcpy(this, &that, sizeof(that));
this->src = new fs_reg[MAX2(that.sources, 3)];
for (unsigned i = 0; i < that.sources; i++)
this->src[i] = that.src[i];
}
fs_inst::~fs_inst()
{
delete[] this->src;
}
void
fs_inst::resize_sources(uint8_t num_sources)
{
if (this->sources != num_sources) {
fs_reg *src = new fs_reg[MAX2(num_sources, 3)];
for (unsigned i = 0; i < MIN2(this->sources, num_sources); ++i)
src[i] = this->src[i];
delete[] this->src;
this->src = src;
this->sources = num_sources;
}
}
void
fs_visitor::VARYING_PULL_CONSTANT_LOAD(const fs_builder &bld,
const fs_reg &dst,
const fs_reg &surf_index,
const fs_reg &varying_offset,
uint32_t const_offset)
{
/* We have our constant surface use a pitch of 4 bytes, so our index can
* be any component of a vector, and then we load 4 contiguous
* components starting from that.
*
* We break down the const_offset to a portion added to the variable offset
* and a portion done using fs_reg::offset, which means that if you have
* GLSL using something like "uniform vec4 a[20]; gl_FragColor = a[i]",
* we'll temporarily generate 4 vec4 loads from offset i * 4, and CSE can
* later notice that those loads are all the same and eliminate the
* redundant ones.
*/
fs_reg vec4_offset = vgrf(glsl_type::uint_type);
bld.ADD(vec4_offset, varying_offset, brw_imm_ud(const_offset & ~0xf));
/* The pull load message will load a vec4 (16 bytes). If we are loading
* a double this means we are only loading 2 elements worth of data.
* We also want to use a 32-bit data type for the dst of the load operation
* so other parts of the driver don't get confused about the size of the
* result.
*/
fs_reg vec4_result = bld.vgrf(BRW_REGISTER_TYPE_F, 4);
fs_inst *inst = bld.emit(FS_OPCODE_VARYING_PULL_CONSTANT_LOAD_LOGICAL,
vec4_result, surf_index, vec4_offset);
inst->size_written = 4 * vec4_result.component_size(inst->exec_size);
fs_reg dw = offset(vec4_result, bld, (const_offset & 0xf) / 4);
switch (type_sz(dst.type)) {
case 2:
shuffle_32bit_load_result_to_16bit_data(bld, dst, dw, 1);
bld.MOV(dst, subscript(dw, dst.type, (const_offset / 2) & 1));
break;
case 4:
bld.MOV(dst, retype(dw, dst.type));
break;
case 8:
shuffle_32bit_load_result_to_64bit_data(bld, dst, dw, 1);
break;
default:
unreachable("Unsupported bit_size");
}
}
/**
* A helper for MOV generation for fixing up broken hardware SEND dependency
* handling.
*/
void
fs_visitor::DEP_RESOLVE_MOV(const fs_builder &bld, int grf)
{
/* The caller always wants uncompressed to emit the minimal extra
* dependencies, and to avoid having to deal with aligning its regs to 2.
*/
const fs_builder ubld = bld.annotate("send dependency resolve")
.half(0);
ubld.MOV(ubld.null_reg_f(), fs_reg(VGRF, grf, BRW_REGISTER_TYPE_F));
}
bool
fs_inst::equals(fs_inst *inst) const
{
return (opcode == inst->opcode &&
dst.equals(inst->dst) &&
src[0].equals(inst->src[0]) &&
src[1].equals(inst->src[1]) &&
src[2].equals(inst->src[2]) &&
saturate == inst->saturate &&
predicate == inst->predicate &&
conditional_mod == inst->conditional_mod &&
mlen == inst->mlen &&
base_mrf == inst->base_mrf &&
target == inst->target &&
eot == inst->eot &&
header_size == inst->header_size &&
shadow_compare == inst->shadow_compare &&
exec_size == inst->exec_size &&
offset == inst->offset);
}
bool
fs_inst::is_send_from_grf() const
{
switch (opcode) {
case FS_OPCODE_VARYING_PULL_CONSTANT_LOAD_GEN7:
case SHADER_OPCODE_SHADER_TIME_ADD:
case FS_OPCODE_INTERPOLATE_AT_SAMPLE:
case FS_OPCODE_INTERPOLATE_AT_SHARED_OFFSET:
case FS_OPCODE_INTERPOLATE_AT_PER_SLOT_OFFSET:
case SHADER_OPCODE_UNTYPED_ATOMIC:
case SHADER_OPCODE_UNTYPED_SURFACE_READ:
case SHADER_OPCODE_UNTYPED_SURFACE_WRITE:
case SHADER_OPCODE_BYTE_SCATTERED_WRITE:
case SHADER_OPCODE_BYTE_SCATTERED_READ:
case SHADER_OPCODE_TYPED_ATOMIC:
case SHADER_OPCODE_TYPED_SURFACE_READ:
case SHADER_OPCODE_TYPED_SURFACE_WRITE:
case SHADER_OPCODE_URB_WRITE_SIMD8:
case SHADER_OPCODE_URB_WRITE_SIMD8_PER_SLOT:
case SHADER_OPCODE_URB_WRITE_SIMD8_MASKED:
case SHADER_OPCODE_URB_WRITE_SIMD8_MASKED_PER_SLOT:
case SHADER_OPCODE_URB_READ_SIMD8:
case SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT:
return true;
case FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD:
return src[1].file == VGRF;
case FS_OPCODE_FB_WRITE:
case FS_OPCODE_FB_READ:
return src[0].file == VGRF;
default:
if (is_tex())
return src[0].file == VGRF;
return false;
}
}
/**
* Returns true if this instruction's sources and destinations cannot
* safely be the same register.
*
* In most cases, a register can be written over safely by the same
* instruction that is its last use. For a single instruction, the
* sources are dereferenced before writing of the destination starts
* (naturally).
*
* However, there are a few cases where this can be problematic:
*
* - Virtual opcodes that translate to multiple instructions in the
* code generator: if src == dst and one instruction writes the
* destination before a later instruction reads the source, then
* src will have been clobbered.
*
* - SIMD16 compressed instructions with certain regioning (see below).
*
* The register allocator uses this information to set up conflicts between
* GRF sources and the destination.
*/
bool
fs_inst::has_source_and_destination_hazard() const
{
switch (opcode) {
case FS_OPCODE_PACK_HALF_2x16_SPLIT:
/* Multiple partial writes to the destination */
return true;
default:
/* The SIMD16 compressed instruction
*
* add(16) g4<1>F g4<8,8,1>F g6<8,8,1>F
*
* is actually decoded in hardware as:
*
* add(8) g4<1>F g4<8,8,1>F g6<8,8,1>F
* add(8) g5<1>F g5<8,8,1>F g7<8,8,1>F
*
* Which is safe. However, if we have uniform accesses
* happening, we get into trouble:
*
* add(8) g4<1>F g4<0,1,0>F g6<8,8,1>F
* add(8) g5<1>F g4<0,1,0>F g7<8,8,1>F
*
* Now our destination for the first instruction overwrote the
* second instruction's src0, and we get garbage for those 8
* pixels. There's a similar issue for the pre-gen6
* pixel_x/pixel_y, which are registers of 16-bit values and thus
* would get stomped by the first decode as well.
*/
if (exec_size == 16) {
for (int i = 0; i < sources; i++) {
if (src[i].file == VGRF && (src[i].stride == 0 ||
src[i].type == BRW_REGISTER_TYPE_UW ||
src[i].type == BRW_REGISTER_TYPE_W ||
src[i].type == BRW_REGISTER_TYPE_UB ||
src[i].type == BRW_REGISTER_TYPE_B)) {
return true;
}
}
}
return false;
}
}
bool
fs_inst::is_copy_payload(const brw::simple_allocator &grf_alloc) const
{
if (this->opcode != SHADER_OPCODE_LOAD_PAYLOAD)
return false;
fs_reg reg = this->src[0];
if (reg.file != VGRF || reg.offset != 0 || reg.stride != 1)
return false;
if (grf_alloc.sizes[reg.nr] * REG_SIZE != this->size_written)
return false;
for (int i = 0; i < this->sources; i++) {
reg.type = this->src[i].type;
if (!this->src[i].equals(reg))
return false;
if (i < this->header_size) {
reg.offset += REG_SIZE;
} else {
reg = horiz_offset(reg, this->exec_size);
}
}
return true;
}
bool
fs_inst::can_do_source_mods(const struct gen_device_info *devinfo)
{
if (devinfo->gen == 6 && is_math())
return false;
if (is_send_from_grf())
return false;
if (!backend_instruction::can_do_source_mods())
return false;
return true;
}
bool
fs_inst::can_change_types() const
{
return dst.type == src[0].type &&
!src[0].abs && !src[0].negate && !saturate &&
(opcode == BRW_OPCODE_MOV ||
(opcode == BRW_OPCODE_SEL &&
dst.type == src[1].type &&
predicate != BRW_PREDICATE_NONE &&
!src[1].abs && !src[1].negate));
}
void
fs_reg::init()
{
memset(this, 0, sizeof(*this));
type = BRW_REGISTER_TYPE_UD;
stride = 1;
}
/** Generic unset register constructor. */
fs_reg::fs_reg()
{
init();
this->file = BAD_FILE;
}
fs_reg::fs_reg(struct ::brw_reg reg) :
backend_reg(reg)
{
this->offset = 0;
this->stride = 1;
if (this->file == IMM &&
(this->type != BRW_REGISTER_TYPE_V &&
this->type != BRW_REGISTER_TYPE_UV &&
this->type != BRW_REGISTER_TYPE_VF)) {
this->stride = 0;
}
}
bool
fs_reg::equals(const fs_reg &r) const
{
return (this->backend_reg::equals(r) &&
stride == r.stride);
}
bool
fs_reg::is_contiguous() const
{
return stride == 1;
}
unsigned
fs_reg::component_size(unsigned width) const
{
const unsigned stride = ((file != ARF && file != FIXED_GRF) ? this->stride :
hstride == 0 ? 0 :
1 << (hstride - 1));
return MAX2(width * stride, 1) * type_sz(type);
}
extern "C" int
type_size_scalar(const struct glsl_type *type)
{
unsigned int size, i;
switch (type->base_type) {
case GLSL_TYPE_UINT:
case GLSL_TYPE_INT:
case GLSL_TYPE_FLOAT:
case GLSL_TYPE_BOOL:
return type->components();
case GLSL_TYPE_UINT16:
case GLSL_TYPE_INT16:
case GLSL_TYPE_FLOAT16:
return DIV_ROUND_UP(type->components(), 2);
case GLSL_TYPE_DOUBLE:
case GLSL_TYPE_UINT64:
case GLSL_TYPE_INT64:
return type->components() * 2;
case GLSL_TYPE_ARRAY:
return type_size_scalar(type->fields.array) * type->length;
case GLSL_TYPE_STRUCT:
size = 0;
for (i = 0; i < type->length; i++) {
size += type_size_scalar(type->fields.structure[i].type);
}
return size;
case GLSL_TYPE_SAMPLER:
/* Samplers take up no register space, since they're baked in at
* link time.
*/
return 0;
case GLSL_TYPE_ATOMIC_UINT:
return 0;
case GLSL_TYPE_SUBROUTINE:
return 1;
case GLSL_TYPE_IMAGE:
return BRW_IMAGE_PARAM_SIZE;
case GLSL_TYPE_VOID:
case GLSL_TYPE_ERROR:
case GLSL_TYPE_INTERFACE:
case GLSL_TYPE_FUNCTION:
unreachable("not reached");
}
return 0;
}
/**
* Create a MOV to read the timestamp register.
*
* The caller is responsible for emitting the MOV. The return value is
* the destination of the MOV, with extra parameters set.
*/
fs_reg
fs_visitor::get_timestamp(const fs_builder &bld)
{
assert(devinfo->gen >= 7);
fs_reg ts = fs_reg(retype(brw_vec4_reg(BRW_ARCHITECTURE_REGISTER_FILE,
BRW_ARF_TIMESTAMP,
0),
BRW_REGISTER_TYPE_UD));
fs_reg dst = fs_reg(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UD);
/* We want to read the 3 fields we care about even if it's not enabled in
* the dispatch.
*/
bld.group(4, 0).exec_all().MOV(dst, ts);
return dst;
}
void
fs_visitor::emit_shader_time_begin()
{
/* We want only the low 32 bits of the timestamp. Since it's running
* at the GPU clock rate of ~1.2ghz, it will roll over every ~3 seconds,
* which is plenty of time for our purposes. It is identical across the
* EUs, but since it's tracking GPU core speed it will increment at a
* varying rate as render P-states change.
*/
shader_start_time = component(
get_timestamp(bld.annotate("shader time start")), 0);
}
void
fs_visitor::emit_shader_time_end()
{
/* Insert our code just before the final SEND with EOT. */
exec_node *end = this->instructions.get_tail();
assert(end && ((fs_inst *) end)->eot);
const fs_builder ibld = bld.annotate("shader time end")
.exec_all().at(NULL, end);
const fs_reg timestamp = get_timestamp(ibld);
/* We only use the low 32 bits of the timestamp - see
* emit_shader_time_begin()).
*
* We could also check if render P-states have changed (or anything
* else that might disrupt timing) by setting smear to 2 and checking if
* that field is != 0.
*/
const fs_reg shader_end_time = component(timestamp, 0);
/* Check that there weren't any timestamp reset events (assuming these
* were the only two timestamp reads that happened).
*/
const fs_reg reset = component(timestamp, 2);
set_condmod(BRW_CONDITIONAL_Z,
ibld.AND(ibld.null_reg_ud(), reset, brw_imm_ud(1u)));
ibld.IF(BRW_PREDICATE_NORMAL);
fs_reg start = shader_start_time;
start.negate = true;
const fs_reg diff = component(fs_reg(VGRF, alloc.allocate(1),
BRW_REGISTER_TYPE_UD),
0);
const fs_builder cbld = ibld.group(1, 0);
cbld.group(1, 0).ADD(diff, start, shader_end_time);
/* If there were no instructions between the two timestamp gets, the diff
* is 2 cycles. Remove that overhead, so I can forget about that when
* trying to determine the time taken for single instructions.
*/
cbld.ADD(diff, diff, brw_imm_ud(-2u));
SHADER_TIME_ADD(cbld, 0, diff);
SHADER_TIME_ADD(cbld, 1, brw_imm_ud(1u));
ibld.emit(BRW_OPCODE_ELSE);
SHADER_TIME_ADD(cbld, 2, brw_imm_ud(1u));
ibld.emit(BRW_OPCODE_ENDIF);
}
void
fs_visitor::SHADER_TIME_ADD(const fs_builder &bld,
int shader_time_subindex,
fs_reg value)
{
int index = shader_time_index * 3 + shader_time_subindex;
struct brw_reg offset = brw_imm_d(index * BRW_SHADER_TIME_STRIDE);
fs_reg payload;
if (dispatch_width == 8)
payload = vgrf(glsl_type::uvec2_type);
else
payload = vgrf(glsl_type::uint_type);
bld.emit(SHADER_OPCODE_SHADER_TIME_ADD, fs_reg(), payload, offset, value);
}
void
fs_visitor::vfail(const char *format, va_list va)
{
char *msg;
if (failed)
return;
failed = true;
msg = ralloc_vasprintf(mem_ctx, format, va);
msg = ralloc_asprintf(mem_ctx, "%s compile failed: %s\n", stage_abbrev, msg);
this->fail_msg = msg;
if (debug_enabled) {
fprintf(stderr, "%s", msg);
}
}
void
fs_visitor::fail(const char *format, ...)
{
va_list va;
va_start(va, format);
vfail(format, va);
va_end(va);
}
/**
* Mark this program as impossible to compile with dispatch width greater
* than n.
*
* During the SIMD8 compile (which happens first), we can detect and flag
* things that are unsupported in SIMD16+ mode, so the compiler can skip the
* SIMD16+ compile altogether.
*
* During a compile of dispatch width greater than n (if one happens anyway),
* this just calls fail().
*/
void
fs_visitor::limit_dispatch_width(unsigned n, const char *msg)
{
if (dispatch_width > n) {
fail("%s", msg);
} else {
max_dispatch_width = n;
compiler->shader_perf_log(log_data,
"Shader dispatch width limited to SIMD%d: %s",
n, msg);
}
}
/**
* Returns true if the instruction has a flag that means it won't
* update an entire destination register.
*
* For example, dead code elimination and live variable analysis want to know
* when a write to a variable screens off any preceding values that were in
* it.
*/
bool
fs_inst::is_partial_write() const
{
return ((this->predicate && this->opcode != BRW_OPCODE_SEL) ||
(this->exec_size * type_sz(this->dst.type)) < 32 ||
!this->dst.is_contiguous() ||
this->dst.offset % REG_SIZE != 0);
}
unsigned
fs_inst::components_read(unsigned i) const
{
/* Return zero if the source is not present. */
if (src[i].file == BAD_FILE)
return 0;
switch (opcode) {
case FS_OPCODE_LINTERP:
if (i == 0)
return 2;
else
return 1;
case FS_OPCODE_PIXEL_X:
case FS_OPCODE_PIXEL_Y:
assert(i == 0);
return 2;
case FS_OPCODE_FB_WRITE_LOGICAL:
assert(src[FB_WRITE_LOGICAL_SRC_COMPONENTS].file == IMM);
/* First/second FB write color. */
if (i < 2)
return src[FB_WRITE_LOGICAL_SRC_COMPONENTS].ud;
else
return 1;
case SHADER_OPCODE_TEX_LOGICAL:
case SHADER_OPCODE_TXD_LOGICAL:
case SHADER_OPCODE_TXF_LOGICAL:
case SHADER_OPCODE_TXL_LOGICAL:
case SHADER_OPCODE_TXS_LOGICAL:
case FS_OPCODE_TXB_LOGICAL:
case SHADER_OPCODE_TXF_CMS_LOGICAL:
case SHADER_OPCODE_TXF_CMS_W_LOGICAL:
case SHADER_OPCODE_TXF_UMS_LOGICAL:
case SHADER_OPCODE_TXF_MCS_LOGICAL:
case SHADER_OPCODE_LOD_LOGICAL:
case SHADER_OPCODE_TG4_LOGICAL:
case SHADER_OPCODE_TG4_OFFSET_LOGICAL:
case SHADER_OPCODE_SAMPLEINFO_LOGICAL:
assert(src[TEX_LOGICAL_SRC_COORD_COMPONENTS].file == IMM &&
src[TEX_LOGICAL_SRC_GRAD_COMPONENTS].file == IMM);
/* Texture coordinates. */
if (i == TEX_LOGICAL_SRC_COORDINATE)
return src[TEX_LOGICAL_SRC_COORD_COMPONENTS].ud;
/* Texture derivatives. */
else if ((i == TEX_LOGICAL_SRC_LOD || i == TEX_LOGICAL_SRC_LOD2) &&
opcode == SHADER_OPCODE_TXD_LOGICAL)
return src[TEX_LOGICAL_SRC_GRAD_COMPONENTS].ud;
/* Texture offset. */
else if (i == TEX_LOGICAL_SRC_TG4_OFFSET)
return 2;
/* MCS */
else if (i == TEX_LOGICAL_SRC_MCS && opcode == SHADER_OPCODE_TXF_CMS_W_LOGICAL)
return 2;
else
return 1;
case SHADER_OPCODE_UNTYPED_SURFACE_READ_LOGICAL:
case SHADER_OPCODE_TYPED_SURFACE_READ_LOGICAL:
assert(src[3].file == IMM);
/* Surface coordinates. */
if (i == 0)
return src[3].ud;
/* Surface operation source (ignored for reads). */
else if (i == 1)
return 0;
else
return 1;
case SHADER_OPCODE_UNTYPED_SURFACE_WRITE_LOGICAL:
case SHADER_OPCODE_TYPED_SURFACE_WRITE_LOGICAL:
assert(src[3].file == IMM &&
src[4].file == IMM);
/* Surface coordinates. */
if (i == 0)
return src[3].ud;
/* Surface operation source. */
else if (i == 1)
return src[4].ud;
else
return 1;
case SHADER_OPCODE_BYTE_SCATTERED_READ_LOGICAL:
/* Scattered logical opcodes use the following params:
* src[0] Surface coordinates
* src[1] Surface operation source (ignored for reads)
* src[2] Surface
* src[3] IMM with always 1 dimension.
* src[4] IMM with arg bitsize for scattered read/write 8, 16, 32
*/
assert(src[3].file == IMM &&
src[4].file == IMM);
return i == 1 ? 0 : 1;
case SHADER_OPCODE_BYTE_SCATTERED_WRITE_LOGICAL:
assert(src[3].file == IMM &&
src[4].file == IMM);
return 1;
case SHADER_OPCODE_UNTYPED_ATOMIC_LOGICAL:
case SHADER_OPCODE_TYPED_ATOMIC_LOGICAL: {
assert(src[3].file == IMM &&
src[4].file == IMM);
const unsigned op = src[4].ud;
/* Surface coordinates. */
if (i == 0)
return src[3].ud;
/* Surface operation source. */
else if (i == 1 && op == BRW_AOP_CMPWR)
return 2;
else if (i == 1 && (op == BRW_AOP_INC || op == BRW_AOP_DEC ||
op == BRW_AOP_PREDEC))
return 0;
else
return 1;
}
default:
return 1;
}
}
unsigned
fs_inst::size_read(int arg) const
{
switch (opcode) {
case FS_OPCODE_FB_WRITE:
case FS_OPCODE_FB_READ:
case SHADER_OPCODE_URB_WRITE_SIMD8:
case SHADER_OPCODE_URB_WRITE_SIMD8_PER_SLOT:
case SHADER_OPCODE_URB_WRITE_SIMD8_MASKED:
case SHADER_OPCODE_URB_WRITE_SIMD8_MASKED_PER_SLOT:
case SHADER_OPCODE_URB_READ_SIMD8:
case SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT:
case SHADER_OPCODE_UNTYPED_ATOMIC:
case SHADER_OPCODE_UNTYPED_SURFACE_READ:
case SHADER_OPCODE_UNTYPED_SURFACE_WRITE:
case SHADER_OPCODE_TYPED_ATOMIC:
case SHADER_OPCODE_TYPED_SURFACE_READ:
case SHADER_OPCODE_TYPED_SURFACE_WRITE:
case FS_OPCODE_INTERPOLATE_AT_SAMPLE:
case FS_OPCODE_INTERPOLATE_AT_SHARED_OFFSET:
case FS_OPCODE_INTERPOLATE_AT_PER_SLOT_OFFSET:
case SHADER_OPCODE_BYTE_SCATTERED_WRITE:
case SHADER_OPCODE_BYTE_SCATTERED_READ:
if (arg == 0)
return mlen * REG_SIZE;
break;
case FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD_GEN7:
/* The payload is actually stored in src1 */
if (arg == 1)
return mlen * REG_SIZE;
break;
case FS_OPCODE_LINTERP:
if (arg == 1)
return 16;
break;
case SHADER_OPCODE_LOAD_PAYLOAD:
if (arg < this->header_size)
return REG_SIZE;
break;
case CS_OPCODE_CS_TERMINATE:
case SHADER_OPCODE_BARRIER:
return REG_SIZE;
case SHADER_OPCODE_MOV_INDIRECT:
if (arg == 0) {
assert(src[2].file == IMM);
return src[2].ud;
}
break;
default:
if (is_tex() && arg == 0 && src[0].file == VGRF)
return mlen * REG_SIZE;
break;
}
switch (src[arg].file) {
case UNIFORM:
case IMM:
return components_read(arg) * type_sz(src[arg].type);
case BAD_FILE:
case ARF:
case FIXED_GRF:
case VGRF:
case ATTR:
return components_read(arg) * src[arg].component_size(exec_size);
case MRF:
unreachable("MRF registers are not allowed as sources");
}
return 0;
}
namespace {
/* Return the subset of flag registers that an instruction could
* potentially read or write based on the execution controls and flag
* subregister number of the instruction.
*/
unsigned
flag_mask(const fs_inst *inst)
{
const unsigned start = inst->flag_subreg * 16 + inst->group;
const unsigned end = start + inst->exec_size;
return ((1 << DIV_ROUND_UP(end, 8)) - 1) & ~((1 << (start / 8)) - 1);
}
unsigned
bit_mask(unsigned n)
{
return (n >= CHAR_BIT * sizeof(bit_mask(n)) ? ~0u : (1u << n) - 1);
}
unsigned
flag_mask(const fs_reg &r, unsigned sz)
{
if (r.file == ARF) {
const unsigned start = (r.nr - BRW_ARF_FLAG) * 4 + r.subnr;
const unsigned end = start + sz;
return bit_mask(end) & ~bit_mask(start);
} else {
return 0;
}
}
}
unsigned
fs_inst::flags_read(const gen_device_info *devinfo) const
{
if (predicate == BRW_PREDICATE_ALIGN1_ANYV ||
predicate == BRW_PREDICATE_ALIGN1_ALLV) {
/* The vertical predication modes combine corresponding bits from
* f0.0 and f1.0 on Gen7+, and f0.0 and f0.1 on older hardware.
*/
const unsigned shift = devinfo->gen >= 7 ? 4 : 2;
return flag_mask(this) << shift | flag_mask(this);
} else if (predicate) {
return flag_mask(this);
} else {
unsigned mask = 0;
for (int i = 0; i < sources; i++) {
mask |= flag_mask(src[i], size_read(i));
}
return mask;
}
}
unsigned
fs_inst::flags_written() const
{
if ((conditional_mod && (opcode != BRW_OPCODE_SEL &&
opcode != BRW_OPCODE_IF &&
opcode != BRW_OPCODE_WHILE)) ||
opcode == FS_OPCODE_MOV_DISPATCH_TO_FLAGS) {
return flag_mask(this);
} else {
return flag_mask(dst, size_written);
}
}
/**
* Returns how many MRFs an FS opcode will write over.
*
* Note that this is not the 0 or 1 implied writes in an actual gen
* instruction -- the FS opcodes often generate MOVs in addition.
*/
int
fs_visitor::implied_mrf_writes(fs_inst *inst) const
{
if (inst->mlen == 0)
return 0;
if (inst->base_mrf == -1)
return 0;
switch (inst->opcode) {
case SHADER_OPCODE_RCP:
case SHADER_OPCODE_RSQ:
case SHADER_OPCODE_SQRT:
case SHADER_OPCODE_EXP2:
case SHADER_OPCODE_LOG2:
case SHADER_OPCODE_SIN:
case SHADER_OPCODE_COS:
return 1 * dispatch_width / 8;
case SHADER_OPCODE_POW:
case SHADER_OPCODE_INT_QUOTIENT:
case SHADER_OPCODE_INT_REMAINDER:
return 2 * dispatch_width / 8;
case SHADER_OPCODE_TEX:
case FS_OPCODE_TXB:
case SHADER_OPCODE_TXD:
case SHADER_OPCODE_TXF:
case SHADER_OPCODE_TXF_CMS:
case SHADER_OPCODE_TXF_MCS:
case SHADER_OPCODE_TG4:
case SHADER_OPCODE_TG4_OFFSET:
case SHADER_OPCODE_TXL:
case SHADER_OPCODE_TXS:
case SHADER_OPCODE_LOD:
case SHADER_OPCODE_SAMPLEINFO:
return 1;
case FS_OPCODE_FB_WRITE:
return 2;
case FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD:
case SHADER_OPCODE_GEN4_SCRATCH_READ:
return 1;
case FS_OPCODE_VARYING_PULL_CONSTANT_LOAD_GEN4:
return inst->mlen;
case SHADER_OPCODE_GEN4_SCRATCH_WRITE:
return inst->mlen;
default:
unreachable("not reached");
}
}
fs_reg
fs_visitor::vgrf(const glsl_type *const type)
{
int reg_width = dispatch_width / 8;
return fs_reg(VGRF, alloc.allocate(type_size_scalar(type) * reg_width),
brw_type_for_base_type(type));
}
fs_reg::fs_reg(enum brw_reg_file file, int nr)
{
init();
this->file = file;
this->nr = nr;
this->type = BRW_REGISTER_TYPE_F;
this->stride = (file == UNIFORM ? 0 : 1);
}
fs_reg::fs_reg(enum brw_reg_file file, int nr, enum brw_reg_type type)
{
init();
this->file = file;
this->nr = nr;
this->type = type;
this->stride = (file == UNIFORM ? 0 : 1);
}
/* For SIMD16, we need to follow from the uniform setup of SIMD8 dispatch.
* This brings in those uniform definitions
*/
void
fs_visitor::import_uniforms(fs_visitor *v)
{
this->push_constant_loc = v->push_constant_loc;
this->pull_constant_loc = v->pull_constant_loc;
this->uniforms = v->uniforms;
this->subgroup_id = v->subgroup_id;
}
void
fs_visitor::emit_fragcoord_interpolation(fs_reg wpos)
{
assert(stage == MESA_SHADER_FRAGMENT);
/* gl_FragCoord.x */
bld.MOV(wpos, this->pixel_x);
wpos = offset(wpos, bld, 1);
/* gl_FragCoord.y */
bld.MOV(wpos, this->pixel_y);
wpos = offset(wpos, bld, 1);
/* gl_FragCoord.z */
if (devinfo->gen >= 6) {
bld.MOV(wpos, fs_reg(brw_vec8_grf(payload.source_depth_reg, 0)));
} else {
bld.emit(FS_OPCODE_LINTERP, wpos,
this->delta_xy[BRW_BARYCENTRIC_PERSPECTIVE_PIXEL],
interp_reg(VARYING_SLOT_POS, 2));
}
wpos = offset(wpos, bld, 1);
/* gl_FragCoord.w: Already set up in emit_interpolation */
bld.MOV(wpos, this->wpos_w);
}
enum brw_barycentric_mode
brw_barycentric_mode(enum glsl_interp_mode mode, nir_intrinsic_op op)
{
/* Barycentric modes don't make sense for flat inputs. */
assert(mode != INTERP_MODE_FLAT);
unsigned bary;
switch (op) {
case nir_intrinsic_load_barycentric_pixel:
case nir_intrinsic_load_barycentric_at_offset:
bary = BRW_BARYCENTRIC_PERSPECTIVE_PIXEL;
break;
case nir_intrinsic_load_barycentric_centroid:
bary = BRW_BARYCENTRIC_PERSPECTIVE_CENTROID;
break;
case nir_intrinsic_load_barycentric_sample:
case nir_intrinsic_load_barycentric_at_sample:
bary = BRW_BARYCENTRIC_PERSPECTIVE_SAMPLE;
break;
default:
unreachable("invalid intrinsic");
}
if (mode == INTERP_MODE_NOPERSPECTIVE)
bary += 3;
return (enum brw_barycentric_mode) bary;
}
/**
* Turn one of the two CENTROID barycentric modes into PIXEL mode.
*/
static enum brw_barycentric_mode
centroid_to_pixel(enum brw_barycentric_mode bary)
{
assert(bary == BRW_BARYCENTRIC_PERSPECTIVE_CENTROID ||
bary == BRW_BARYCENTRIC_NONPERSPECTIVE_CENTROID);
return (enum brw_barycentric_mode) ((unsigned) bary - 1);
}
fs_reg *
fs_visitor::emit_frontfacing_interpolation()
{
fs_reg *reg = new(this->mem_ctx) fs_reg(vgrf(glsl_type::bool_type));
if (devinfo->gen >= 6) {
/* Bit 15 of g0.0 is 0 if the polygon is front facing. We want to create
* a boolean result from this (~0/true or 0/false).
*
* We can use the fact that bit 15 is the MSB of g0.0:W to accomplish
* this task in only one instruction:
* - a negation source modifier will flip the bit; and
* - a W -> D type conversion will sign extend the bit into the high
* word of the destination.
*
* An ASR 15 fills the low word of the destination.
*/
fs_reg g0 = fs_reg(retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_W));
g0.negate = true;
bld.ASR(*reg, g0, brw_imm_d(15));
} else {
/* Bit 31 of g1.6 is 0 if the polygon is front facing. We want to create
* a boolean result from this (1/true or 0/false).
*
* Like in the above case, since the bit is the MSB of g1.6:UD we can use
* the negation source modifier to flip it. Unfortunately the SHR
* instruction only operates on UD (or D with an abs source modifier)
* sources without negation.
*
* Instead, use ASR (which will give ~0/true or 0/false).
*/
fs_reg g1_6 = fs_reg(retype(brw_vec1_grf(1, 6), BRW_REGISTER_TYPE_D));
g1_6.negate = true;
bld.ASR(*reg, g1_6, brw_imm_d(31));
}
return reg;
}
void
fs_visitor::compute_sample_position(fs_reg dst, fs_reg int_sample_pos)
{
assert(stage == MESA_SHADER_FRAGMENT);
struct brw_wm_prog_data *wm_prog_data = brw_wm_prog_data(this->prog_data);
assert(dst.type == BRW_REGISTER_TYPE_F);
if (wm_prog_data->persample_dispatch) {
/* Convert int_sample_pos to floating point */
bld.MOV(dst, int_sample_pos);
/* Scale to the range [0, 1] */
bld.MUL(dst, dst, brw_imm_f(1 / 16.0f));
}
else {
/* From ARB_sample_shading specification:
* "When rendering to a non-multisample buffer, or if multisample
* rasterization is disabled, gl_SamplePosition will always be
* (0.5, 0.5).
*/
bld.MOV(dst, brw_imm_f(0.5f));
}
}
fs_reg *
fs_visitor::emit_samplepos_setup()
{
assert(devinfo->gen >= 6);
const fs_builder abld = bld.annotate("compute sample position");
fs_reg *reg = new(this->mem_ctx) fs_reg(vgrf(glsl_type::vec2_type));
fs_reg pos = *reg;
fs_reg int_sample_x = vgrf(glsl_type::int_type);
fs_reg int_sample_y = vgrf(glsl_type::int_type);
/* WM will be run in MSDISPMODE_PERSAMPLE. So, only one of SIMD8 or SIMD16
* mode will be enabled.
*
* From the Ivy Bridge PRM, volume 2 part 1, page 344:
* R31.1:0 Position Offset X/Y for Slot[3:0]
* R31.3:2 Position Offset X/Y for Slot[7:4]
* .....
*
* The X, Y sample positions come in as bytes in thread payload. So, read
* the positions using vstride=16, width=8, hstride=2.
*/
struct brw_reg sample_pos_reg =
stride(retype(brw_vec1_grf(payload.sample_pos_reg, 0),
BRW_REGISTER_TYPE_B), 16, 8, 2);
if (dispatch_width == 8) {
abld.MOV(int_sample_x, fs_reg(sample_pos_reg));
} else {
abld.half(0).MOV(half(int_sample_x, 0), fs_reg(sample_pos_reg));
abld.half(1).MOV(half(int_sample_x, 1),
fs_reg(suboffset(sample_pos_reg, 16)));
}
/* Compute gl_SamplePosition.x */
compute_sample_position(pos, int_sample_x);
pos = offset(pos, abld, 1);
if (dispatch_width == 8) {
abld.MOV(int_sample_y, fs_reg(suboffset(sample_pos_reg, 1)));
} else {
abld.half(0).MOV(half(int_sample_y, 0),
fs_reg(suboffset(sample_pos_reg, 1)));
abld.half(1).MOV(half(int_sample_y, 1),
fs_reg(suboffset(sample_pos_reg, 17)));
}
/* Compute gl_SamplePosition.y */
compute_sample_position(pos, int_sample_y);
return reg;
}
fs_reg *
fs_visitor::emit_sampleid_setup()
{
assert(stage == MESA_SHADER_FRAGMENT);
brw_wm_prog_key *key = (brw_wm_prog_key*) this->key;
assert(devinfo->gen >= 6);
const fs_builder abld = bld.annotate("compute sample id");
fs_reg *reg = new(this->mem_ctx) fs_reg(vgrf(glsl_type::uint_type));
if (!key->multisample_fbo) {
/* As per GL_ARB_sample_shading specification:
* "When rendering to a non-multisample buffer, or if multisample
* rasterization is disabled, gl_SampleID will always be zero."
*/
abld.MOV(*reg, brw_imm_d(0));
} else if (devinfo->gen >= 8) {
/* Sample ID comes in as 4-bit numbers in g1.0:
*
* 15:12 Slot 3 SampleID (only used in SIMD16)
* 11:8 Slot 2 SampleID (only used in SIMD16)
* 7:4 Slot 1 SampleID
* 3:0 Slot 0 SampleID
*
* Each slot corresponds to four channels, so we want to replicate each
* half-byte value to 4 channels in a row:
*
* dst+0: .7 .6 .5 .4 .3 .2 .1 .0
* 7:4 7:4 7:4 7:4 3:0 3:0 3:0 3:0
*
* dst+1: .7 .6 .5 .4 .3 .2 .1 .0 (if SIMD16)
* 15:12 15:12 15:12 15:12 11:8 11:8 11:8 11:8
*
* First, we read g1.0 with a <1,8,0>UB region, causing the first 8
* channels to read the first byte (7:0), and the second group of 8
* channels to read the second byte (15:8). Then, we shift right by
* a vector immediate of <4, 4, 4, 4, 0, 0, 0, 0>, moving the slot 1 / 3
* values into place. Finally, we AND with 0xf to keep the low nibble.
*
* shr(16) tmp<1>W g1.0<1,8,0>B 0x44440000:V
* and(16) dst<1>D tmp<8,8,1>W 0xf:W
*
* TODO: These payload bits exist on Gen7 too, but they appear to always
* be zero, so this code fails to work. We should find out why.
*/
fs_reg tmp(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UW);
abld.SHR(tmp, fs_reg(stride(retype(brw_vec1_grf(1, 0),
BRW_REGISTER_TYPE_UB), 1, 8, 0)),
brw_imm_v(0x44440000));
abld.AND(*reg, tmp, brw_imm_w(0xf));
} else {
const fs_reg t1 = component(fs_reg(VGRF, alloc.allocate(1),
BRW_REGISTER_TYPE_UD), 0);
const fs_reg t2(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UW);
/* The PS will be run in MSDISPMODE_PERSAMPLE. For example with
* 8x multisampling, subspan 0 will represent sample N (where N
* is 0, 2, 4 or 6), subspan 1 will represent sample 1, 3, 5 or
* 7. We can find the value of N by looking at R0.0 bits 7:6
* ("Starting Sample Pair Index (SSPI)") and multiplying by two
* (since samples are always delivered in pairs). That is, we
* compute 2*((R0.0 & 0xc0) >> 6) == (R0.0 & 0xc0) >> 5. Then
* we need to add N to the sequence (0, 0, 0, 0, 1, 1, 1, 1) in
* case of SIMD8 and sequence (0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2,
* 2, 3, 3, 3, 3) in case of SIMD16. We compute this sequence by
* populating a temporary variable with the sequence (0, 1, 2, 3),
* and then reading from it using vstride=1, width=4, hstride=0.
* These computations hold good for 4x multisampling as well.
*
* For 2x MSAA and SIMD16, we want to use the sequence (0, 1, 0, 1):
* the first four slots are sample 0 of subspan 0; the next four
* are sample 1 of subspan 0; the third group is sample 0 of
* subspan 1, and finally sample 1 of subspan 1.
*/
/* SKL+ has an extra bit for the Starting Sample Pair Index to
* accomodate 16x MSAA.
*/
abld.exec_all().group(1, 0)
.AND(t1, fs_reg(retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_UD)),
brw_imm_ud(0xc0));
abld.exec_all().group(1, 0).SHR(t1, t1, brw_imm_d(5));
/* This works for both SIMD8 and SIMD16 */
abld.exec_all().group(4, 0).MOV(t2, brw_imm_v(0x3210));
/* This special instruction takes care of setting vstride=1,
* width=4, hstride=0 of t2 during an ADD instruction.
*/
abld.emit(FS_OPCODE_SET_SAMPLE_ID, *reg, t1, t2);
}
return reg;
}
fs_reg *
fs_visitor::emit_samplemaskin_setup()
{
assert(stage == MESA_SHADER_FRAGMENT);
struct brw_wm_prog_data *wm_prog_data = brw_wm_prog_data(this->prog_data);
assert(devinfo->gen >= 6);
fs_reg *reg = new(this->mem_ctx) fs_reg(vgrf(glsl_type::int_type));
fs_reg coverage_mask(retype(brw_vec8_grf(payload.sample_mask_in_reg, 0),
BRW_REGISTER_TYPE_D));
if (wm_prog_data->persample_dispatch) {
/* gl_SampleMaskIn[] comes from two sources: the input coverage mask,
* and a mask representing which sample is being processed by the
* current shader invocation.
*
* From the OES_sample_variables specification:
* "When per-sample shading is active due to the use of a fragment input
* qualified by "sample" or due to the use of the gl_SampleID or
* gl_SamplePosition variables, only the bit for the current sample is
* set in gl_SampleMaskIn."
*/
const fs_builder abld = bld.annotate("compute gl_SampleMaskIn");
if (nir_system_values[SYSTEM_VALUE_SAMPLE_ID].file == BAD_FILE)
nir_system_values[SYSTEM_VALUE_SAMPLE_ID] = *emit_sampleid_setup();
fs_reg one = vgrf(glsl_type::int_type);
fs_reg enabled_mask = vgrf(glsl_type::int_type);
abld.MOV(one, brw_imm_d(1));
abld.SHL(enabled_mask, one, nir_system_values[SYSTEM_VALUE_SAMPLE_ID]);
abld.AND(*reg, enabled_mask, coverage_mask);
} else {
/* In per-pixel mode, the coverage mask is sufficient. */
*reg = coverage_mask;
}
return reg;
}
fs_reg
fs_visitor::resolve_source_modifiers(const fs_reg &src)
{
if (!src.abs && !src.negate)
return src;
fs_reg temp = bld.vgrf(src.type);
bld.MOV(temp, src);
return temp;
}
void
fs_visitor::emit_discard_jump()
{
assert(brw_wm_prog_data(this->prog_data)->uses_kill);
/* For performance, after a discard, jump to the end of the
* shader if all relevant channels have been discarded.
*/
fs_inst *discard_jump = bld.emit(FS_OPCODE_DISCARD_JUMP);
discard_jump->flag_subreg = 1;
discard_jump->predicate = BRW_PREDICATE_ALIGN1_ANY4H;
discard_jump->predicate_inverse = true;
}
void
fs_visitor::emit_gs_thread_end()
{
assert(stage == MESA_SHADER_GEOMETRY);
struct brw_gs_prog_data *gs_prog_data = brw_gs_prog_data(prog_data);
if (gs_compile->control_data_header_size_bits > 0) {
emit_gs_control_data_bits(this->final_gs_vertex_count);
}
const fs_builder abld = bld.annotate("thread end");
fs_inst *inst;
if (gs_prog_data->static_vertex_count != -1) {
foreach_in_list_reverse(fs_inst, prev, &this->instructions) {
if (prev->opcode == SHADER_OPCODE_URB_WRITE_SIMD8 ||
prev->opcode == SHADER_OPCODE_URB_WRITE_SIMD8_MASKED ||
prev->opcode == SHADER_OPCODE_URB_WRITE_SIMD8_PER_SLOT ||
prev->opcode == SHADER_OPCODE_URB_WRITE_SIMD8_MASKED_PER_SLOT) {
prev->eot = true;
/* Delete now dead instructions. */
foreach_in_list_reverse_safe(exec_node, dead, &this->instructions) {
if (dead == prev)
break;
dead->remove();
}
return;
} else if (prev->is_control_flow() || prev->has_side_effects()) {
break;
}
}
fs_reg hdr = abld.vgrf(BRW_REGISTER_TYPE_UD, 1);
abld.MOV(hdr, fs_reg(retype(brw_vec8_grf(1, 0), BRW_REGISTER_TYPE_UD)));
inst = abld.emit(SHADER_OPCODE_URB_WRITE_SIMD8, reg_undef, hdr);
inst->mlen = 1;
} else {
fs_reg payload = abld.vgrf(BRW_REGISTER_TYPE_UD, 2);
fs_reg *sources = ralloc_array(mem_ctx, fs_reg, 2);
sources[0] = fs_reg(retype(brw_vec8_grf(1, 0), BRW_REGISTER_TYPE_UD));
sources[1] = this->final_gs_vertex_count;
abld.LOAD_PAYLOAD(payload, sources, 2, 2);
inst = abld.emit(SHADER_OPCODE_URB_WRITE_SIMD8, reg_undef, payload);
inst->mlen = 2;
}
inst->eot = true;
inst->offset = 0;
}
void
fs_visitor::assign_curb_setup()
{
unsigned uniform_push_length = DIV_ROUND_UP(stage_prog_data->nr_params, 8);
unsigned ubo_push_length = 0;
unsigned ubo_push_start[4];
for (int i = 0; i < 4; i++) {
ubo_push_start[i] = 8 * (ubo_push_length + uniform_push_length);
ubo_push_length += stage_prog_data->ubo_ranges[i].length;
}
prog_data->curb_read_length = uniform_push_length + ubo_push_length;
/* Map the offsets in the UNIFORM file to fixed HW regs. */
foreach_block_and_inst(block, fs_inst, inst, cfg) {
for (unsigned int i = 0; i < inst->sources; i++) {
if (inst->src[i].file == UNIFORM) {
int uniform_nr = inst->src[i].nr + inst->src[i].offset / 4;
int constant_nr;
if (inst->src[i].nr >= UBO_START) {
/* constant_nr is in 32-bit units, the rest are in bytes */
constant_nr = ubo_push_start[inst->src[i].nr - UBO_START] +
inst->src[i].offset / 4;
} else if (uniform_nr >= 0 && uniform_nr < (int) uniforms) {
constant_nr = push_constant_loc[uniform_nr];
} else {
/* Section 5.11 of the OpenGL 4.1 spec says:
* "Out-of-bounds reads return undefined values, which include
* values from other variables of the active program or zero."
* Just return the first push constant.
*/
constant_nr = 0;
}
struct brw_reg brw_reg = brw_vec1_grf(payload.num_regs +
constant_nr / 8,
constant_nr % 8);
brw_reg.abs = inst->src[i].abs;
brw_reg.negate = inst->src[i].negate;
assert(inst->src[i].stride == 0);
inst->src[i] = byte_offset(
retype(brw_reg, inst->src[i].type),
inst->src[i].offset % 4);
}
}
}
/* This may be updated in assign_urb_setup or assign_vs_urb_setup. */
this->first_non_payload_grf = payload.num_regs + prog_data->curb_read_length;
}
void
fs_visitor::calculate_urb_setup()
{
assert(stage == MESA_SHADER_FRAGMENT);
struct brw_wm_prog_data *prog_data = brw_wm_prog_data(this->prog_data);
brw_wm_prog_key *key = (brw_wm_prog_key*) this->key;
memset(prog_data->urb_setup, -1,
sizeof(prog_data->urb_setup[0]) * VARYING_SLOT_MAX);
int urb_next = 0;
/* Figure out where each of the incoming setup attributes lands. */
if (devinfo->gen >= 6) {
if (_mesa_bitcount_64(nir->info.inputs_read &
BRW_FS_VARYING_INPUT_MASK) <= 16) {
/* The SF/SBE pipeline stage can do arbitrary rearrangement of the
* first 16 varying inputs, so we can put them wherever we want.
* Just put them in order.
*
* This is useful because it means that (a) inputs not used by the
* fragment shader won't take up valuable register space, and (b) we
* won't have to recompile the fragment shader if it gets paired with
* a different vertex (or geometry) shader.
*/
for (unsigned int i = 0; i < VARYING_SLOT_MAX; i++) {
if (nir->info.inputs_read & BRW_FS_VARYING_INPUT_MASK &
BITFIELD64_BIT(i)) {
prog_data->urb_setup[i] = urb_next++;
}
}
} else {
/* We have enough input varyings that the SF/SBE pipeline stage can't
* arbitrarily rearrange them to suit our whim; we have to put them
* in an order that matches the output of the previous pipeline stage
* (geometry or vertex shader).
*/
struct brw_vue_map prev_stage_vue_map;
brw_compute_vue_map(devinfo, &prev_stage_vue_map,
key->input_slots_valid,
nir->info.separate_shader);
int first_slot =
brw_compute_first_urb_slot_required(nir->info.inputs_read,
&prev_stage_vue_map);
assert(prev_stage_vue_map.num_slots <= first_slot + 32);
for (int slot = first_slot; slot < prev_stage_vue_map.num_slots;
slot++) {
int varying = prev_stage_vue_map.slot_to_varying[slot];
if (varying != BRW_VARYING_SLOT_PAD &&
(nir->info.inputs_read & BRW_FS_VARYING_INPUT_MASK &
BITFIELD64_BIT(varying))) {
prog_data->urb_setup[varying] = slot - first_slot;
}
}
urb_next = prev_stage_vue_map.num_slots - first_slot;
}
} else {
/* FINISHME: The sf doesn't map VS->FS inputs for us very well. */
for (unsigned int i = 0; i < VARYING_SLOT_MAX; i++) {
/* Point size is packed into the header, not as a general attribute */
if (i == VARYING_SLOT_PSIZ)
continue;
if (key->input_slots_valid & BITFIELD64_BIT(i)) {
/* The back color slot is skipped when the front color is
* also written to. In addition, some slots can be
* written in the vertex shader and not read in the
* fragment shader. So the register number must always be
* incremented, mapped or not.
*/
if (_mesa_varying_slot_in_fs((gl_varying_slot) i))
prog_data->urb_setup[i] = urb_next;
urb_next++;
}
}
/*
* It's a FS only attribute, and we did interpolation for this attribute
* in SF thread. So, count it here, too.
*
* See compile_sf_prog() for more info.
*/
if (nir->info.inputs_read & BITFIELD64_BIT(VARYING_SLOT_PNTC))
prog_data->urb_setup[VARYING_SLOT_PNTC] = urb_next++;
}
prog_data->num_varying_inputs = urb_next;
}
void
fs_visitor::assign_urb_setup()
{
assert(stage == MESA_SHADER_FRAGMENT);
struct brw_wm_prog_data *prog_data = brw_wm_prog_data(this->prog_data);
int urb_start = payload.num_regs + prog_data->base.curb_read_length;
/* Offset all the urb_setup[] index by the actual position of the
* setup regs, now that the location of the constants has been chosen.
*/
foreach_block_and_inst(block, fs_inst, inst, cfg) {
if (inst->opcode == FS_OPCODE_LINTERP) {
assert(inst->src[1].file == FIXED_GRF);
inst->src[1].nr += urb_start;
}
if (inst->opcode == FS_OPCODE_CINTERP) {
assert(inst->src[0].file == FIXED_GRF);
inst->src[0].nr += urb_start;
}
}
/* Each attribute is 4 setup channels, each of which is half a reg. */
this->first_non_payload_grf += prog_data->num_varying_inputs * 2;
}
void
fs_visitor::convert_attr_sources_to_hw_regs(fs_inst *inst)
{
for (int i = 0; i < inst->sources; i++) {
if (inst->src[i].file == ATTR) {
int grf = payload.num_regs +
prog_data->curb_read_length +
inst->src[i].nr +
inst->src[i].offset / REG_SIZE;
/* As explained at brw_reg_from_fs_reg, From the Haswell PRM:
*
* VertStride must be used to cross GRF register boundaries. This
* rule implies that elements within a 'Width' cannot cross GRF
* boundaries.
*
* So, for registers that are large enough, we have to split the exec
* size in two and trust the compression state to sort it out.
*/
unsigned total_size = inst->exec_size *
inst->src[i].stride *
type_sz(inst->src[i].type);
assert(total_size <= 2 * REG_SIZE);
const unsigned exec_size =
(total_size <= REG_SIZE) ? inst->exec_size : inst->exec_size / 2;
unsigned width = inst->src[i].stride == 0 ? 1 : exec_size;
struct brw_reg reg =
stride(byte_offset(retype(brw_vec8_grf(grf, 0), inst->src[i].type),
inst->src[i].offset % REG_SIZE),
exec_size * inst->src[i].stride,
width, inst->src[i].stride);
reg.abs = inst->src[i].abs;
reg.negate = inst->src[i].negate;
inst->src[i] = reg;
}
}
}
void
fs_visitor::assign_vs_urb_setup()
{
struct brw_vs_prog_data *vs_prog_data = brw_vs_prog_data(prog_data);
assert(stage == MESA_SHADER_VERTEX);
/* Each attribute is 4 regs. */
this->first_non_payload_grf += 4 * vs_prog_data->nr_attribute_slots;
assert(vs_prog_data->base.urb_read_length <= 15);
/* Rewrite all ATTR file references to the hw grf that they land in. */
foreach_block_and_inst(block, fs_inst, inst, cfg) {
convert_attr_sources_to_hw_regs(inst);
}
}
void
fs_visitor::assign_tcs_single_patch_urb_setup()
{
assert(stage == MESA_SHADER_TESS_CTRL);
/* Rewrite all ATTR file references to HW_REGs. */
foreach_block_and_inst(block, fs_inst, inst, cfg) {
convert_attr_sources_to_hw_regs(inst);
}
}
void
fs_visitor::assign_tes_urb_setup()
{
assert(stage == MESA_SHADER_TESS_EVAL);
struct brw_vue_prog_data *vue_prog_data = brw_vue_prog_data(prog_data);
first_non_payload_grf += 8 * vue_prog_data->urb_read_length;
/* Rewrite all ATTR file references to HW_REGs. */
foreach_block_and_inst(block, fs_inst, inst, cfg) {
convert_attr_sources_to_hw_regs(inst);
}
}
void
fs_visitor::assign_gs_urb_setup()
{
assert(stage == MESA_SHADER_GEOMETRY);
struct brw_vue_prog_data *vue_prog_data = brw_vue_prog_data(prog_data);
first_non_payload_grf +=
8 * vue_prog_data->urb_read_length * nir->info.gs.vertices_in;
foreach_block_and_inst(block, fs_inst, inst, cfg) {
/* Rewrite all ATTR file references to GRFs. */
convert_attr_sources_to_hw_regs(inst);
}
}
/**
* Split large virtual GRFs into separate components if we can.
*
* This is mostly duplicated with what brw_fs_vector_splitting does,
* but that's really conservative because it's afraid of doing
* splitting that doesn't result in real progress after the rest of
* the optimization phases, which would cause infinite looping in
* optimization. We can do it once here, safely. This also has the
* opportunity to split interpolated values, or maybe even uniforms,
* which we don't have at the IR level.
*
* We want to split, because virtual GRFs are what we register
* allocate and spill (due to contiguousness requirements for some
* instructions), and they're what we naturally generate in the
* codegen process, but most virtual GRFs don't actually need to be
* contiguous sets of GRFs. If we split, we'll end up with reduced
* live intervals and better dead code elimination and coalescing.
*/
void
fs_visitor::split_virtual_grfs()
{
/* Compact the register file so we eliminate dead vgrfs. This
* only defines split points for live registers, so if we have
* too large dead registers they will hit assertions later.
*/
compact_virtual_grfs();
int num_vars = this->alloc.count;
/* Count the total number of registers */
int reg_count = 0;
int vgrf_to_reg[num_vars];
for (int i = 0; i < num_vars; i++) {
vgrf_to_reg[i] = reg_count;
reg_count += alloc.sizes[i];
}
/* An array of "split points". For each register slot, this indicates
* if this slot can be separated from the previous slot. Every time an
* instruction uses multiple elements of a register (as a source or
* destination), we mark the used slots as inseparable. Then we go
* through and split the registers into the smallest pieces we can.
*/
bool split_points[reg_count];
memset(split_points, 0, sizeof(split_points));
/* Mark all used registers as fully splittable */
foreach_block_and_inst(block, fs_inst, inst, cfg) {
if (inst->dst.file == VGRF) {
int reg = vgrf_to_reg[inst->dst.nr];
for (unsigned j = 1; j < this->alloc.sizes[inst->dst.nr]; j++)
split_points[reg + j] = true;
}
for (int i = 0; i < inst->sources; i++) {
if (inst->src[i].file == VGRF) {
int reg = vgrf_to_reg[inst->src[i].nr];
for (unsigned j = 1; j < this->alloc.sizes[inst->src[i].nr]; j++)
split_points[reg + j] = true;
}
}
}
foreach_block_and_inst(block, fs_inst, inst, cfg) {
if (inst->dst.file == VGRF) {
int reg = vgrf_to_reg[inst->dst.nr] + inst->dst.offset / REG_SIZE;
for (unsigned j = 1; j < regs_written(inst); j++)
split_points[reg + j] = false;
}
for (int i = 0; i < inst->sources; i++) {
if (inst->src[i].file == VGRF) {
int reg = vgrf_to_reg[inst->src[i].nr] + inst->src[i].offset / REG_SIZE;
for (unsigned j = 1; j < regs_read(inst, i); j++)
split_points[reg + j] = false;
}
}
}
int new_virtual_grf[reg_count];
int new_reg_offset[reg_count];
int reg = 0;
for (int i = 0; i < num_vars; i++) {
/* The first one should always be 0 as a quick sanity check. */
assert(split_points[reg] == false);
/* j = 0 case */
new_reg_offset[reg] = 0;
reg++;
int offset = 1;
/* j > 0 case */
for (unsigned j = 1; j < alloc.sizes[i]; j++) {
/* If this is a split point, reset the offset to 0 and allocate a
* new virtual GRF for the previous offset many registers
*/
if (split_points[reg]) {
assert(offset <= MAX_VGRF_SIZE);
int grf = alloc.allocate(offset);
for (int k = reg - offset; k < reg; k++)
new_virtual_grf[k] = grf;
offset = 0;
}
new_reg_offset[reg] = offset;
offset++;
reg++;
}
/* The last one gets the original register number */
assert(offset <= MAX_VGRF_SIZE);
alloc.sizes[i] = offset;
for (int k = reg - offset; k < reg; k++)
new_virtual_grf[k] = i;
}
assert(reg == reg_count);
foreach_block_and_inst(block, fs_inst, inst, cfg) {
if (inst->dst.file == VGRF) {
reg = vgrf_to_reg[inst->dst.nr] + inst->dst.offset / REG_SIZE;
inst->dst.nr = new_virtual_grf[reg];
inst->dst.offset = new_reg_offset[reg] * REG_SIZE +
inst->dst.offset % REG_SIZE;
assert((unsigned)new_reg_offset[reg] < alloc.sizes[new_virtual_grf[reg]]);
}
for (int i = 0; i < inst->sources; i++) {
if (inst->src[i].file == VGRF) {
reg = vgrf_to_reg[inst->src[i].nr] + inst->src[i].offset / REG_SIZE;
inst->src[i].nr = new_virtual_grf[reg];
inst->src[i].offset = new_reg_offset[reg] * REG_SIZE +
inst->src[i].offset % REG_SIZE;
assert((unsigned)new_reg_offset[reg] < alloc.sizes[new_virtual_grf[reg]]);
}
}
}
invalidate_live_intervals();
}
/**
* Remove unused virtual GRFs and compact the virtual_grf_* arrays.
*
* During code generation, we create tons of temporary variables, many of
* which get immediately killed and are never used again. Yet, in later
* optimization and analysis passes, such as compute_live_intervals, we need
* to loop over all the virtual GRFs. Compacting them can save a lot of
* overhead.
*/
bool
fs_visitor::compact_virtual_grfs()
{
bool progress = false;
int remap_table[this->alloc.count];
memset(remap_table, -1, sizeof(remap_table));
/* Mark which virtual GRFs are used. */
foreach_block_and_inst(block, const fs_inst, inst, cfg) {
if (inst->dst.file == VGRF)
remap_table[inst->dst.nr] = 0;
for (int i = 0; i < inst->sources; i++) {
if (inst->src[i].file == VGRF)
remap_table[inst->src[i].nr] = 0;
}
}
/* Compact the GRF arrays. */
int new_index = 0;
for (unsigned i = 0; i < this->alloc.count; i++) {
if (remap_table[i] == -1) {
/* We just found an unused register. This means that we are
* actually going to compact something.
*/
progress = true;
} else {
remap_table[i] = new_index;
alloc.sizes[new_index] = alloc.sizes[i];
invalidate_live_intervals();
++new_index;
}
}
this->alloc.count = new_index;
/* Patch all the instructions to use the newly renumbered registers */
foreach_block_and_inst(block, fs_inst, inst, cfg) {
if (inst->dst.file == VGRF)
inst->dst.nr = remap_table[inst->dst.nr];
for (int i = 0; i < inst->sources; i++) {
if (inst->src[i].file == VGRF)
inst->src[i].nr = remap_table[inst->src[i].nr];
}
}
/* Patch all the references to delta_xy, since they're used in register
* allocation. If they're unused, switch them to BAD_FILE so we don't
* think some random VGRF is delta_xy.
*/
for (unsigned i = 0; i < ARRAY_SIZE(delta_xy); i++) {
if (delta_xy[i].file == VGRF) {
if (remap_table[delta_xy[i].nr] != -1) {
delta_xy[i].nr = remap_table[delta_xy[i].nr];
} else {
delta_xy[i].file = BAD_FILE;
}
}
}
return progress;
}
static int
get_subgroup_id_param_index(const brw_stage_prog_data *prog_data)
{
if (prog_data->nr_params == 0)
return -1;
/* The local thread id is always the last parameter in the list */
uint32_t last_param = prog_data->param[prog_data->nr_params - 1];
if (last_param == BRW_PARAM_BUILTIN_SUBGROUP_ID)
return prog_data->nr_params - 1;
return -1;
}
/**
* Struct for handling complex alignments.
*
* A complex alignment is stored as multiplier and an offset. A value is
* considered to be aligned if it is {offset} larger than a multiple of {mul}.
* For instance, with an alignment of {8, 2}, cplx_align_apply would do the
* following:
*
* N | cplx_align_apply({8, 2}, N)
* ----+-----------------------------
* 4 | 6
* 6 | 6
* 8 | 14
* 10 | 14
* 12 | 14
* 14 | 14
* 16 | 22
*/
struct cplx_align {
unsigned mul:4;
unsigned offset:4;
};
#define CPLX_ALIGN_MAX_MUL 8
static void
cplx_align_assert_sane(struct cplx_align a)
{
assert(a.mul > 0 && util_is_power_of_two(a.mul));
assert(a.offset < a.mul);
}
/**
* Combines two alignments to produce a least multiple of sorts.
*
* The returned alignment is the smallest (in terms of multiplier) such that
* anything aligned to both a and b will be aligned to the new alignment.
* This function will assert-fail if a and b are not compatible, i.e. if the
* offset parameters are such that no common alignment is possible.
*/
static struct cplx_align
cplx_align_combine(struct cplx_align a, struct cplx_align b)
{
cplx_align_assert_sane(a);
cplx_align_assert_sane(b);
/* Assert that the alignments agree. */
assert((a.offset & (b.mul - 1)) == (b.offset & (a.mul - 1)));
return a.mul > b.mul ? a : b;
}
/**
* Apply a complex alignment
*
* This function will return the smallest number greater than or equal to
* offset that is aligned to align.
*/
static unsigned
cplx_align_apply(struct cplx_align align, unsigned offset)
{
return ALIGN(offset - align.offset, align.mul) + align.offset;
}
#define UNIFORM_SLOT_SIZE 4
struct uniform_slot_info {
/** True if the given uniform slot is live */
unsigned is_live:1;
/** True if this slot and the next slot must remain contiguous */
unsigned contiguous:1;
struct cplx_align align;
};
static void
mark_uniform_slots_read(struct uniform_slot_info *slots,
unsigned num_slots, unsigned alignment)
{
assert(alignment > 0 && util_is_power_of_two(alignment));
assert(alignment <= CPLX_ALIGN_MAX_MUL);
/* We can't align a slot to anything less than the slot size */
alignment = MAX2(alignment, UNIFORM_SLOT_SIZE);
struct cplx_align align = {alignment, 0};
cplx_align_assert_sane(align);
for (unsigned i = 0; i < num_slots; i++) {
slots[i].is_live = true;
if (i < num_slots - 1)
slots[i].contiguous = true;
align.offset = (i * UNIFORM_SLOT_SIZE) & (align.mul - 1);
if (slots[i].align.mul == 0) {
slots[i].align = align;
} else {
slots[i].align = cplx_align_combine(slots[i].align, align);
}
}
}
/**
* Assign UNIFORM file registers to either push constants or pull constants.
*
* We allow a fragment shader to have more than the specified minimum
* maximum number of fragment shader uniform components (64). If
* there are too many of these, they'd fill up all of register space.
* So, this will push some of them out to the pull constant buffer and
* update the program to load them.
*/
void
fs_visitor::assign_constant_locations()
{
/* Only the first compile gets to decide on locations. */
if (push_constant_loc) {
assert(pull_constant_loc);
return;
}
struct uniform_slot_info slots[uniforms];
memset(slots, 0, sizeof(slots));
foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
for (int i = 0 ; i < inst->sources; i++) {
if (inst->src[i].file != UNIFORM)
continue;
/* NIR tightly packs things so the uniform number might not be
* aligned (if we have a double right after a float, for instance).
* This is fine because the process of re-arranging them will ensure
* that things are properly aligned. The offset into that uniform,
* however, must be aligned.
*
* In Vulkan, we have explicit offsets but everything is crammed
* into a single "variable" so inst->src[i].nr will always be 0.
* Everything will be properly aligned relative to that one base.
*/
assert(inst->src[i].offset % type_sz(inst->src[i].type) == 0);
unsigned u = inst->src[i].nr +
inst->src[i].offset / UNIFORM_SLOT_SIZE;
if (u >= uniforms)
continue;
unsigned slots_read;
if (inst->opcode == SHADER_OPCODE_MOV_INDIRECT && i == 0) {
slots_read = DIV_ROUND_UP(inst->src[2].ud, UNIFORM_SLOT_SIZE);
} else {
unsigned bytes_read = inst->components_read(i) *
type_sz(inst->src[i].type);
slots_read = DIV_ROUND_UP(bytes_read, UNIFORM_SLOT_SIZE);
}
assert(u + slots_read <= uniforms);
mark_uniform_slots_read(&slots[u], slots_read,
type_sz(inst->src[i].type));
}
}
int subgroup_id_index = get_subgroup_id_param_index(stage_prog_data);
/* Only allow 16 registers (128 uniform components) as push constants.
*
* Just demote the end of the list. We could probably do better
* here, demoting things that are rarely used in the program first.
*
* If changing this value, note the limitation about total_regs in
* brw_curbe.c.
*/
unsigned int max_push_components = 16 * 8;
if (subgroup_id_index >= 0)
max_push_components--; /* Save a slot for the thread ID */
/* We push small arrays, but no bigger than 16 floats. This is big enough
* for a vec4 but hopefully not large enough to push out other stuff. We
* should probably use a better heuristic at some point.
*/
const unsigned int max_chunk_size = 16;
unsigned int num_push_constants = 0;
unsigned int num_pull_constants = 0;
push_constant_loc = ralloc_array(mem_ctx, int, uniforms);
pull_constant_loc = ralloc_array(mem_ctx, int, uniforms);
/* Default to -1 meaning no location */
memset(push_constant_loc, -1, uniforms * sizeof(*push_constant_loc));
memset(pull_constant_loc, -1, uniforms * sizeof(*pull_constant_loc));
int chunk_start = -1;
struct cplx_align align;
for (unsigned u = 0; u < uniforms; u++) {
if (!slots[u].is_live) {
assert(chunk_start == -1);
continue;
}
/* Skip subgroup_id_index to put it in the last push register. */
if (subgroup_id_index == (int)u)
continue;
if (chunk_start == -1) {
chunk_start = u;
align = slots[u].align;
} else {
/* Offset into the chunk */
unsigned chunk_offset = (u - chunk_start) * UNIFORM_SLOT_SIZE;
/* Shift the slot alignment down by the chunk offset so it is
* comparable with the base chunk alignment.
*/
struct cplx_align slot_align = slots[u].align;
slot_align.offset =
(slot_align.offset - chunk_offset) & (align.mul - 1);
align = cplx_align_combine(align, slot_align);
}
/* Sanity check the alignment */
cplx_align_assert_sane(align);
if (slots[u].contiguous)
continue;
/* Adjust the alignment to be in terms of slots, not bytes */
assert((align.mul & (UNIFORM_SLOT_SIZE - 1)) == 0);
assert((align.offset & (UNIFORM_SLOT_SIZE - 1)) == 0);
align.mul /= UNIFORM_SLOT_SIZE;
align.offset /= UNIFORM_SLOT_SIZE;
unsigned push_start_align = cplx_align_apply(align, num_push_constants);
unsigned chunk_size = u - chunk_start + 1;
if ((!compiler->supports_pull_constants && u < UBO_START) ||
(chunk_size < max_chunk_size &&
push_start_align + chunk_size <= max_push_components)) {
/* Align up the number of push constants */
num_push_constants = push_start_align;
for (unsigned i = 0; i < chunk_size; i++)
push_constant_loc[chunk_start + i] = num_push_constants++;
} else {
/* We need to pull this one */
num_pull_constants = cplx_align_apply(align, num_pull_constants);
for (unsigned i = 0; i < chunk_size; i++)
pull_constant_loc[chunk_start + i] = num_pull_constants++;
}
/* Reset the chunk and start again */
chunk_start = -1;
}
/* Add the CS local thread ID uniform at the end of the push constants */
if (subgroup_id_index >= 0)
push_constant_loc[subgroup_id_index] = num_push_constants++;
/* As the uniforms are going to be reordered, stash the old array and
* create two new arrays for push/pull params.
*/
uint32_t *param = stage_prog_data->param;
stage_prog_data->nr_params = num_push_constants;
if (num_push_constants) {
stage_prog_data->param = rzalloc_array(mem_ctx, uint32_t,
num_push_constants);
} else {
stage_prog_data->param = NULL;
}
assert(stage_prog_data->nr_pull_params == 0);
assert(stage_prog_data->pull_param == NULL);
if (num_pull_constants > 0) {
stage_prog_data->nr_pull_params = num_pull_constants;
stage_prog_data->pull_param = rzalloc_array(mem_ctx, uint32_t,
num_pull_constants);
}
/* Now that we know how many regular uniforms we'll push, reduce the
* UBO push ranges so we don't exceed the 3DSTATE_CONSTANT limits.
*/
unsigned push_length = DIV_ROUND_UP(stage_prog_data->nr_params, 8);
for (int i = 0; i < 4; i++) {
struct brw_ubo_range *range = &prog_data->ubo_ranges[i];
if (push_length + range->length > 64)
range->length = 64 - push_length;
push_length += range->length;
}
assert(push_length <= 64);
/* Up until now, the param[] array has been indexed by reg + offset
* of UNIFORM registers. Move pull constants into pull_param[] and
* condense param[] to only contain the uniforms we chose to push.
*
* NOTE: Because we are condensing the params[] array, we know that
* push_constant_loc[i] <= i and we can do it in one smooth loop without
* having to make a copy.
*/
for (unsigned int i = 0; i < uniforms; i++) {
uint32_t value = param[i];
if (pull_constant_loc[i] != -1) {
stage_prog_data->pull_param[pull_constant_loc[i]] = value;
} else if (push_constant_loc[i] != -1) {
stage_prog_data->param[push_constant_loc[i]] = value;
}
}
ralloc_free(param);
}
bool
fs_visitor::get_pull_locs(const fs_reg &src,
unsigned *out_surf_index,
unsigned *out_pull_index)
{
assert(src.file == UNIFORM);
if (src.nr >= UBO_START) {
const struct brw_ubo_range *range =
&prog_data->ubo_ranges[src.nr - UBO_START];
/* If this access is in our (reduced) range, use the push data. */
if (src.offset / 32 < range->length)
return false;
*out_surf_index = prog_data->binding_table.ubo_start + range->block;
*out_pull_index = (32 * range->start + src.offset) / 4;
return true;
}
const unsigned location = src.nr + src.offset / 4;
if (location < uniforms && pull_constant_loc[location] != -1) {
/* A regular uniform push constant */
*out_surf_index = stage_prog_data->binding_table.pull_constants_start;
*out_pull_index = pull_constant_loc[location];
return true;
}
return false;
}
/**
* Replace UNIFORM register file access with either UNIFORM_PULL_CONSTANT_LOAD
* or VARYING_PULL_CONSTANT_LOAD instructions which load values into VGRFs.
*/
void
fs_visitor::lower_constant_loads()
{
unsigned index, pull_index;
foreach_block_and_inst_safe (block, fs_inst, inst, cfg) {
/* Set up the annotation tracking for new generated instructions. */
const fs_builder ibld(this, block, inst);
for (int i = 0; i < inst->sources; i++) {
if (inst->src[i].file != UNIFORM)
continue;
/* We'll handle this case later */
if (inst->opcode == SHADER_OPCODE_MOV_INDIRECT && i == 0)
continue;
if (!get_pull_locs(inst->src[i], &index, &pull_index))
continue;
assert(inst->src[i].stride == 0);
const unsigned block_sz = 64; /* Fetch one cacheline at a time. */
const fs_builder ubld = ibld.exec_all().group(block_sz / 4, 0);
const fs_reg dst = ubld.vgrf(BRW_REGISTER_TYPE_UD);
const unsigned base = pull_index * 4;
ubld.emit(FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD,
dst, brw_imm_ud(index), brw_imm_ud(base & ~(block_sz - 1)));
/* Rewrite the instruction to use the temporary VGRF. */
inst->src[i].file = VGRF;
inst->src[i].nr = dst.nr;
inst->src[i].offset = (base & (block_sz - 1)) +
inst->src[i].offset % 4;
brw_mark_surface_used(prog_data, index);
}
if (inst->opcode == SHADER_OPCODE_MOV_INDIRECT &&
inst->src[0].file == UNIFORM) {
if (!get_pull_locs(inst->src[0], &index, &pull_index))
continue;
VARYING_PULL_CONSTANT_LOAD(ibld, inst->dst,
brw_imm_ud(index),
inst->src[1],
pull_index * 4);
inst->remove(block);
brw_mark_surface_used(prog_data, index);
}
}
invalidate_live_intervals();
}
bool
fs_visitor::opt_algebraic()
{
bool progress = false;
foreach_block_and_inst(block, fs_inst, inst, cfg) {
switch (inst->opcode) {
case BRW_OPCODE_MOV:
if (inst->src[0].file != IMM)
break;
if (inst->saturate) {
if (inst->dst.type != inst->src[0].type)
assert(!"unimplemented: saturate mixed types");
if (brw_saturate_immediate(inst->dst.type,
&inst->src[0].as_brw_reg())) {
inst->saturate = false;
progress = true;
}
}
break;
case BRW_OPCODE_MUL:
if (inst->src[1].file != IMM)
continue;
/* a * 1.0 = a */
if (inst->src[1].is_one()) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[1] = reg_undef;
progress = true;
break;
}
/* a * -1.0 = -a */
if (inst->src[1].is_negative_one()) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[0].negate = !inst->src[0].negate;
inst->src[1] = reg_undef;
progress = true;
break;
}
/* a * 0.0 = 0.0 */
if (inst->src[1].is_zero()) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[0] = inst->src[1];
inst->src[1] = reg_undef;
progress = true;
break;
}
if (inst->src[0].file == IMM) {
assert(inst->src[0].type == BRW_REGISTER_TYPE_F);
inst->opcode = BRW_OPCODE_MOV;
inst->src[0].f *= inst->src[1].f;
inst->src[1] = reg_undef;
progress = true;
break;
}
break;
case BRW_OPCODE_ADD:
if (inst->src[1].file != IMM)
continue;
/* a + 0.0 = a */
if (inst->src[1].is_zero()) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[1] = reg_undef;
progress = true;
break;
}
if (inst->src[0].file == IMM) {
assert(inst->src[0].type == BRW_REGISTER_TYPE_F);
inst->opcode = BRW_OPCODE_MOV;
inst->src[0].f += inst->src[1].f;
inst->src[1] = reg_undef;
progress = true;
break;
}
break;
case BRW_OPCODE_OR:
if (inst->src[0].equals(inst->src[1])) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[1] = reg_undef;
progress = true;
break;
}
break;
case BRW_OPCODE_LRP:
if (inst->src[1].equals(inst->src[2])) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[0] = inst->src[1];
inst->src[1] = reg_undef;
inst->src[2] = reg_undef;
progress = true;
break;
}
break;
case BRW_OPCODE_CMP:
if (inst->conditional_mod == BRW_CONDITIONAL_GE &&
inst->src[0].abs &&
inst->src[0].negate &&
inst->src[1].is_zero()) {
inst->src[0].abs = false;
inst->src[0].negate = false;
inst->conditional_mod = BRW_CONDITIONAL_Z;
progress = true;
break;
}
break;
case BRW_OPCODE_SEL:
if (inst->src[0].equals(inst->src[1])) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[1] = reg_undef;
inst->predicate = BRW_PREDICATE_NONE;
inst->predicate_inverse = false;
progress = true;
} else if (inst->saturate && inst->src[1].file == IMM) {
switch (inst->conditional_mod) {
case BRW_CONDITIONAL_LE:
case BRW_CONDITIONAL_L:
switch (inst->src[1].type) {
case BRW_REGISTER_TYPE_F:
if (inst->src[1].f >= 1.0f) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[1] = reg_undef;
inst->conditional_mod = BRW_CONDITIONAL_NONE;
progress = true;
}
break;
default:
break;
}
break;
case BRW_CONDITIONAL_GE:
case BRW_CONDITIONAL_G:
switch (inst->src[1].type) {
case BRW_REGISTER_TYPE_F:
if (inst->src[1].f <= 0.0f) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[1] = reg_undef;
inst->conditional_mod = BRW_CONDITIONAL_NONE;
progress = true;
}
break;
default:
break;
}
default:
break;
}
}
break;
case BRW_OPCODE_MAD:
if (inst->src[1].is_zero() || inst->src[2].is_zero()) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[1] = reg_undef;
inst->src[2] = reg_undef;
progress = true;
} else if (inst->src[0].is_zero()) {
inst->opcode = BRW_OPCODE_MUL;
inst->src[0] = inst->src[2];
inst->src[2] = reg_undef;
progress = true;
} else if (inst->src[1].is_one()) {
inst->opcode = BRW_OPCODE_ADD;
inst->src[1] = inst->src[2];
inst->src[2] = reg_undef;
progress = true;
} else if (inst->src[2].is_one()) {
inst->opcode = BRW_OPCODE_ADD;
inst->src[2] = reg_undef;
progress = true;
} else if (inst->src[1].file == IMM && inst->src[2].file == IMM) {
inst->opcode = BRW_OPCODE_ADD;
inst->src[1].f *= inst->src[2].f;
inst->src[2] = reg_undef;
progress = true;
}
break;
case SHADER_OPCODE_BROADCAST:
if (is_uniform(inst->src[0])) {
inst->opcode = BRW_OPCODE_MOV;
inst->sources = 1;
inst->force_writemask_all = true;
progress = true;
} else if (inst->src[1].file == IMM) {
inst->opcode = BRW_OPCODE_MOV;
/* It's possible that the selected component will be too large and
* overflow the register. This can happen if someone does a
* readInvocation() from GLSL or SPIR-V and provides an OOB
* invocationIndex. If this happens and we some how manage
* to constant fold it in and get here, then component() may cause
* us to start reading outside of the VGRF which will lead to an
* assert later. Instead, just let it wrap around if it goes over
* exec_size.
*/
const unsigned comp = inst->src[1].ud & (inst->exec_size - 1);
inst->src[0] = component(inst->src[0], comp);
inst->sources = 1;
inst->force_writemask_all = true;
progress = true;
}
break;
default:
break;
}
/* Swap if src[0] is immediate. */
if (progress && inst->is_commutative()) {
if (inst->src[0].file == IMM) {
fs_reg tmp = inst->src[1];
inst->src[1] = inst->src[0];
inst->src[0] = tmp;
}
}
}
return progress;
}
/**
* Optimize sample messages that have constant zero values for the trailing
* texture coordinates. We can just reduce the message length for these
* instructions instead of reserving a register for it. Trailing parameters
* that aren't sent default to zero anyway. This will cause the dead code
* eliminator to remove the MOV instruction that would otherwise be emitted to
* set up the zero value.
*/
bool
fs_visitor::opt_zero_samples()
{
/* Gen4 infers the texturing opcode based on the message length so we can't
* change it.
*/
if (devinfo->gen < 5)
return false;
bool progress = false;
foreach_block_and_inst(block, fs_inst, inst, cfg) {
if (!inst->is_tex())
continue;
fs_inst *load_payload = (fs_inst *) inst->prev;
if (load_payload->is_head_sentinel() ||
load_payload->opcode != SHADER_OPCODE_LOAD_PAYLOAD)
continue;
/* We don't want to remove the message header or the first parameter.
* Removing the first parameter is not allowed, see the Haswell PRM
* volume 7, page 149:
*
* "Parameter 0 is required except for the sampleinfo message, which
* has no parameter 0"
*/
while (inst->mlen > inst->header_size + inst->exec_size / 8 &&
load_payload->src[(inst->mlen - inst->header_size) /
(inst->exec_size / 8) +
inst->header_size - 1].is_zero()) {
inst->mlen -= inst->exec_size / 8;
progress = true;
}
}
if (progress)
invalidate_live_intervals();
return progress;
}
/**
* Optimize sample messages which are followed by the final RT write.
*
* CHV, and GEN9+ can mark a texturing SEND instruction with EOT to have its
* results sent directly to the framebuffer, bypassing the EU. Recognize the
* final texturing results copied to the framebuffer write payload and modify
* them to write to the framebuffer directly.
*/
bool
fs_visitor::opt_sampler_eot()
{
brw_wm_prog_key *key = (brw_wm_prog_key*) this->key;
if (stage != MESA_SHADER_FRAGMENT)
return false;
if (devinfo->gen != 9 && !devinfo->is_cherryview)
return false;
/* FINISHME: It should be possible to implement this optimization when there
* are multiple drawbuffers.
*/
if (key->nr_color_regions != 1)
return false;
/* Requires emitting a bunch of saturating MOV instructions during logical
* send lowering to clamp the color payload, which the sampler unit isn't
* going to do for us.
*/
if (key->clamp_fragment_color)
return false;
/* Look for a texturing instruction immediately before the final FB_WRITE. */
bblock_t *block = cfg->blocks[cfg->num_blocks - 1];
fs_inst *fb_write = (fs_inst *)block->end();
assert(fb_write->eot);
assert(fb_write->opcode == FS_OPCODE_FB_WRITE_LOGICAL);
/* There wasn't one; nothing to do. */
if (unlikely(fb_write->prev->is_head_sentinel()))
return false;
fs_inst *tex_inst = (fs_inst *) fb_write->prev;
/* 3D Sampler » Messages » Message Format
*
* “Response Length of zero is allowed on all SIMD8* and SIMD16* sampler
* messages except sample+killpix, resinfo, sampleinfo, LOD, and gather4*”
*/
if (tex_inst->opcode != SHADER_OPCODE_TEX_LOGICAL &&
tex_inst->opcode != SHADER_OPCODE_TXD_LOGICAL &&
tex_inst->opcode != SHADER_OPCODE_TXF_LOGICAL &&
tex_inst->opcode != SHADER_OPCODE_TXL_LOGICAL &&
tex_inst->opcode != FS_OPCODE_TXB_LOGICAL &&
tex_inst->opcode != SHADER_OPCODE_TXF_CMS_LOGICAL &&
tex_inst->opcode != SHADER_OPCODE_TXF_CMS_W_LOGICAL &&
tex_inst->opcode != SHADER_OPCODE_TXF_UMS_LOGICAL)
return false;
/* XXX - This shouldn't be necessary. */
if (tex_inst->prev->is_head_sentinel())
return false;
/* Check that the FB write sources are fully initialized by the single
* texturing instruction.
*/
for (unsigned i = 0; i < FB_WRITE_LOGICAL_NUM_SRCS; i++) {
if (i == FB_WRITE_LOGICAL_SRC_COLOR0) {
if (!fb_write->src[i].equals(tex_inst->dst) ||
fb_write->size_read(i) != tex_inst->size_written)
return false;
} else if (i != FB_WRITE_LOGICAL_SRC_COMPONENTS) {
if (fb_write->src[i].file != BAD_FILE)
return false;
}
}
assert(!tex_inst->eot); /* We can't get here twice */
assert((tex_inst->offset & (0xff << 24)) == 0);
const fs_builder ibld(this, block, tex_inst);
tex_inst->offset |= fb_write->target << 24;
tex_inst->eot = true;
tex_inst->dst = ibld.null_reg_ud();
tex_inst->size_written = 0;
fb_write->remove(cfg->blocks[cfg->num_blocks - 1]);
/* Marking EOT is sufficient, lower_logical_sends() will notice the EOT
* flag and submit a header together with the sampler message as required
* by the hardware.
*/
invalidate_live_intervals();
return true;
}
bool
fs_visitor::opt_register_renaming()
{
bool progress = false;
int depth = 0;
int remap[alloc.count];
memset(remap, -1, sizeof(int) * alloc.count);
foreach_block_and_inst(block, fs_inst, inst, cfg) {
if (inst->opcode == BRW_OPCODE_IF || inst->opcode == BRW_OPCODE_DO) {
depth++;
} else if (inst->opcode == BRW_OPCODE_ENDIF ||
inst->opcode == BRW_OPCODE_WHILE) {
depth--;
}
/* Rewrite instruction sources. */
for (int i = 0; i < inst->sources; i++) {
if (inst->src[i].file == VGRF &&
remap[inst->src[i].nr] != -1 &&
remap[inst->src[i].nr] != inst->src[i].nr) {
inst->src[i].nr = remap[inst->src[i].nr];
progress = true;
}
}
const int dst = inst->dst.nr;
if (depth == 0 &&
inst->dst.file == VGRF &&
alloc.sizes[inst->dst.nr] * REG_SIZE == inst->size_written &&
!inst->is_partial_write()) {
if (remap[dst] == -1) {
remap[dst] = dst;
} else {
remap[dst] = alloc.allocate(regs_written(inst));
inst->dst.nr = remap[dst];
progress = true;
}
} else if (inst->dst.file == VGRF &&
remap[dst] != -1 &&
remap[dst] != dst) {
inst->dst.nr = remap[dst];
progress = true;
}
}
if (progress) {
invalidate_live_intervals();
for (unsigned i = 0; i < ARRAY_SIZE(delta_xy); i++) {
if (delta_xy[i].file == VGRF && remap[delta_xy[i].nr] != -1) {
delta_xy[i].nr = remap[delta_xy[i].nr];
}
}
}
return progress;
}
/**
* Remove redundant or useless discard jumps.
*
* For example, we can eliminate jumps in the following sequence:
*
* discard-jump (redundant with the next jump)
* discard-jump (useless; jumps to the next instruction)
* placeholder-halt
*/
bool
fs_visitor::opt_redundant_discard_jumps()
{
bool progress = false;
bblock_t *last_bblock = cfg->blocks[cfg->num_blocks - 1];
fs_inst *placeholder_halt = NULL;
foreach_inst_in_block_reverse(fs_inst, inst, last_bblock) {
if (inst->opcode == FS_OPCODE_PLACEHOLDER_HALT) {
placeholder_halt = inst;
break;
}
}
if (!placeholder_halt)
return false;
/* Delete any HALTs immediately before the placeholder halt. */
for (fs_inst *prev = (fs_inst *) placeholder_halt->prev;
!prev->is_head_sentinel() && prev->opcode == FS_OPCODE_DISCARD_JUMP;
prev = (fs_inst *) placeholder_halt->prev) {
prev->remove(last_bblock);
progress = true;
}
if (progress)
invalidate_live_intervals();
return progress;
}
/**
* Compute a bitmask with GRF granularity with a bit set for each GRF starting
* from \p r.offset which overlaps the region starting at \p s.offset and
* spanning \p ds bytes.
*/
static inline unsigned
mask_relative_to(const fs_reg &r, const fs_reg &s, unsigned ds)
{
const int rel_offset = reg_offset(s) - reg_offset(r);
const int shift = rel_offset / REG_SIZE;
const unsigned n = DIV_ROUND_UP(rel_offset % REG_SIZE + ds, REG_SIZE);
assert(reg_space(r) == reg_space(s) &&
shift >= 0 && shift < int(8 * sizeof(unsigned)));
return ((1 << n) - 1) << shift;
}
bool
fs_visitor::compute_to_mrf()
{
bool progress = false;
int next_ip = 0;
/* No MRFs on Gen >= 7. */
if (devinfo->gen >= 7)
return false;
calculate_live_intervals();
foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
int ip = next_ip;
next_ip++;
if (inst->opcode != BRW_OPCODE_MOV ||
inst->is_partial_write() ||
inst->dst.file != MRF || inst->src[0].file != VGRF ||
inst->dst.type != inst->src[0].type ||
inst->src[0].abs || inst->src[0].negate ||
!inst->src[0].is_contiguous() ||
inst->src[0].offset % REG_SIZE != 0)
continue;
/* Can't compute-to-MRF this GRF if someone else was going to
* read it later.
*/
if (this->virtual_grf_end[inst->src[0].nr] > ip)
continue;
/* Found a move of a GRF to a MRF. Let's see if we can go rewrite the
* things that computed the value of all GRFs of the source region. The
* regs_left bitset keeps track of the registers we haven't yet found a
* generating instruction for.
*/
unsigned regs_left = (1 << regs_read(inst, 0)) - 1;
foreach_inst_in_block_reverse_starting_from(fs_inst, scan_inst, inst) {
if (regions_overlap(scan_inst->dst, scan_inst->size_written,
inst->src[0], inst->size_read(0))) {
/* Found the last thing to write our reg we want to turn
* into a compute-to-MRF.
*/
/* If this one instruction didn't populate all the
* channels, bail. We might be able to rewrite everything
* that writes that reg, but it would require smarter
* tracking.
*/
if (scan_inst->is_partial_write())
break;
/* Handling things not fully contained in the source of the copy
* would need us to understand coalescing out more than one MOV at
* a time.
*/
if (!region_contained_in(scan_inst->dst, scan_inst->size_written,
inst->src[0], inst->size_read(0)))
break;
/* SEND instructions can't have MRF as a destination. */
if (scan_inst->mlen)
break;
if (devinfo->gen == 6) {
/* gen6 math instructions must have the destination be
* GRF, so no compute-to-MRF for them.
*/
if (scan_inst->is_math()) {
break;
}
}
/* Clear the bits for any registers this instruction overwrites. */
regs_left &= ~mask_relative_to(
inst->src[0], scan_inst->dst, scan_inst->size_written);
if (!regs_left)
break;
}
/* We don't handle control flow here. Most computation of
* values that end up in MRFs are shortly before the MRF
* write anyway.
*/
if (block->start() == scan_inst)
break;
/* You can't read from an MRF, so if someone else reads our
* MRF's source GRF that we wanted to rewrite, that stops us.
*/
bool interfered = false;
for (int i = 0; i < scan_inst->sources; i++) {
if (regions_overlap(scan_inst->src[i], scan_inst->size_read(i),
inst->src[0], inst->size_read(0))) {
interfered = true;
}
}
if (interfered)
break;
if (regions_overlap(scan_inst->dst, scan_inst->size_written,
inst->dst, inst->size_written)) {
/* If somebody else writes our MRF here, we can't
* compute-to-MRF before that.
*/
break;
}
if (scan_inst->mlen > 0 && scan_inst->base_mrf != -1 &&
regions_overlap(fs_reg(MRF, scan_inst->base_mrf), scan_inst->mlen * REG_SIZE,
inst->dst, inst->size_written)) {
/* Found a SEND instruction, which means that there are
* live values in MRFs from base_mrf to base_mrf +
* scan_inst->mlen - 1. Don't go pushing our MRF write up
* above it.
*/
break;
}
}
if (regs_left)
continue;
/* Found all generating instructions of our MRF's source value, so it
* should be safe to rewrite them to point to the MRF directly.
*/
regs_left = (1 << regs_read(inst, 0)) - 1;
foreach_inst_in_block_reverse_starting_from(fs_inst, scan_inst, inst) {
if (regions_overlap(scan_inst->dst, scan_inst->size_written,
inst->src[0], inst->size_read(0))) {
/* Clear the bits for any registers this instruction overwrites. */
regs_left &= ~mask_relative_to(
inst->src[0], scan_inst->dst, scan_inst->size_written);
const unsigned rel_offset = reg_offset(scan_inst->dst) -
reg_offset(inst->src[0]);
if (inst->dst.nr & BRW_MRF_COMPR4) {
/* Apply the same address transformation done by the hardware
* for COMPR4 MRF writes.
*/
assert(rel_offset < 2 * REG_SIZE);
scan_inst->dst.nr = inst->dst.nr + rel_offset / REG_SIZE * 4;
/* Clear the COMPR4 bit if the generating instruction is not
* compressed.
*/
if (scan_inst->size_written < 2 * REG_SIZE)
scan_inst->dst.nr &= ~BRW_MRF_COMPR4;
} else {
/* Calculate the MRF number the result of this instruction is
* ultimately written to.
*/
scan_inst->dst.nr = inst->dst.nr + rel_offset / REG_SIZE;
}
scan_inst->dst.file = MRF;
scan_inst->dst.offset = inst->dst.offset + rel_offset % REG_SIZE;
scan_inst->saturate |= inst->saturate;
if (!regs_left)
break;
}
}
assert(!regs_left);
inst->remove(block);
progress = true;
}
if (progress)
invalidate_live_intervals();
return progress;
}
/**
* Eliminate FIND_LIVE_CHANNEL instructions occurring outside any control
* flow. We could probably do better here with some form of divergence
* analysis.
*/
bool
fs_visitor::eliminate_find_live_channel()
{
bool progress = false;
unsigned depth = 0;
if (!brw_stage_has_packed_dispatch(devinfo, stage, stage_prog_data)) {
/* The optimization below assumes that channel zero is live on thread
* dispatch, which may not be the case if the fixed function dispatches
* threads sparsely.
*/
return false;
}
foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
switch (inst->opcode) {
case BRW_OPCODE_IF:
case BRW_OPCODE_DO:
depth++;
break;
case BRW_OPCODE_ENDIF:
case BRW_OPCODE_WHILE:
depth--;
break;
case FS_OPCODE_DISCARD_JUMP:
/* This can potentially make control flow non-uniform until the end
* of the program.
*/
return progress;
case SHADER_OPCODE_FIND_LIVE_CHANNEL:
if (depth == 0) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[0] = brw_imm_ud(0u);
inst->sources = 1;
inst->force_writemask_all = true;
progress = true;
}
break;
default:
break;
}
}
return progress;
}
/**
* Once we've generated code, try to convert normal FS_OPCODE_FB_WRITE
* instructions to FS_OPCODE_REP_FB_WRITE.
*/
void
fs_visitor::emit_repclear_shader()
{
brw_wm_prog_key *key = (brw_wm_prog_key*) this->key;
int base_mrf = 0;
int color_mrf = base_mrf + 2;
fs_inst *mov;
if (uniforms > 0) {
mov = bld.exec_all().group(4, 0)
.MOV(brw_message_reg(color_mrf),
fs_reg(UNIFORM, 0, BRW_REGISTER_TYPE_F));
} else {
struct brw_reg reg =
brw_reg(BRW_GENERAL_REGISTER_FILE, 2, 3, 0, 0, BRW_REGISTER_TYPE_F,
BRW_VERTICAL_STRIDE_8, BRW_WIDTH_2, BRW_HORIZONTAL_STRIDE_4,
BRW_SWIZZLE_XYZW, WRITEMASK_XYZW);
mov = bld.exec_all().group(4, 0)
.MOV(vec4(brw_message_reg(color_mrf)), fs_reg(reg));
}
fs_inst *write;
if (key->nr_color_regions == 1) {
write = bld.emit(FS_OPCODE_REP_FB_WRITE);
write->saturate = key->clamp_fragment_color;
write->base_mrf = color_mrf;
write->target = 0;
write->header_size = 0;
write->mlen = 1;
} else {
assume(key->nr_color_regions > 0);
for (int i = 0; i < key->nr_color_regions; ++i) {
write = bld.emit(FS_OPCODE_REP_FB_WRITE);
write->saturate = key->clamp_fragment_color;
write->base_mrf = base_mrf;
write->target = i;
write->header_size = 2;
write->mlen = 3;
}
}
write->eot = true;
calculate_cfg();
assign_constant_locations();
assign_curb_setup();
/* Now that we have the uniform assigned, go ahead and force it to a vec4. */
if (uniforms > 0) {
assert(mov->src[0].file == FIXED_GRF);
mov->src[0] = brw_vec4_grf(mov->src[0].nr, 0);
}
}
/**
* Walks through basic blocks, looking for repeated MRF writes and
* removing the later ones.
*/
bool
fs_visitor::remove_duplicate_mrf_writes()
{
fs_inst *last_mrf_move[BRW_MAX_MRF(devinfo->gen)];
bool progress = false;
/* Need to update the MRF tracking for compressed instructions. */
if (dispatch_width >= 16)
return false;
memset(last_mrf_move, 0, sizeof(last_mrf_move));
foreach_block_and_inst_safe (block, fs_inst, inst, cfg) {
if (inst->is_control_flow()) {
memset(last_mrf_move, 0, sizeof(last_mrf_move));
}
if (inst->opcode == BRW_OPCODE_MOV &&
inst->dst.file == MRF) {
fs_inst *prev_inst = last_mrf_move[inst->dst.nr];
if (prev_inst && inst->equals(prev_inst)) {
inst->remove(block);
progress = true;
continue;
}
}
/* Clear out the last-write records for MRFs that were overwritten. */
if (inst->dst.file == MRF) {
last_mrf_move[inst->dst.nr] = NULL;
}
if (inst->mlen > 0 && inst->base_mrf != -1) {
/* Found a SEND instruction, which will include two or fewer
* implied MRF writes. We could do better here.
*/
for (int i = 0; i < implied_mrf_writes(inst); i++) {
last_mrf_move[inst->base_mrf + i] = NULL;
}
}
/* Clear out any MRF move records whose sources got overwritten. */
for (unsigned i = 0; i < ARRAY_SIZE(last_mrf_move); i++) {
if (last_mrf_move[i] &&
regions_overlap(inst->dst, inst->size_written,
last_mrf_move[i]->src[0],
last_mrf_move[i]->size_read(0))) {
last_mrf_move[i] = NULL;
}
}
if (inst->opcode == BRW_OPCODE_MOV &&
inst->dst.file == MRF &&
inst->src[0].file != ARF &&
!inst->is_partial_write()) {
last_mrf_move[inst->dst.nr] = inst;
}
}
if (progress)
invalidate_live_intervals();
return progress;
}
/**
* Rounding modes for conversion instructions are included for each
* conversion, but right now it is a state. So once it is set,
* we don't need to call it again for subsequent calls.
*
* This is useful for vector/matrices conversions, as setting the
* mode once is enough for the full vector/matrix
*/
bool
fs_visitor::remove_extra_rounding_modes()
{
bool progress = false;
foreach_block (block, cfg) {
brw_rnd_mode prev_mode = BRW_RND_MODE_UNSPECIFIED;
foreach_inst_in_block_safe (fs_inst, inst, block) {
if (inst->opcode == SHADER_OPCODE_RND_MODE) {
assert(inst->src[0].file == BRW_IMMEDIATE_VALUE);
const brw_rnd_mode mode = (brw_rnd_mode) inst->src[0].d;
if (mode == prev_mode) {
inst->remove(block);
progress = true;
} else {
prev_mode = mode;
}
}
}
}
if (progress)
invalidate_live_intervals();
return progress;
}
static void
clear_deps_for_inst_src(fs_inst *inst, bool *deps, int first_grf, int grf_len)
{
/* Clear the flag for registers that actually got read (as expected). */
for (int i = 0; i < inst->sources; i++) {
int grf;
if (inst->src[i].file == VGRF || inst->src[i].file == FIXED_GRF) {
grf = inst->src[i].nr;
} else {
continue;
}
if (grf >= first_grf &&
grf < first_grf + grf_len) {
deps[grf - first_grf] = false;
if (inst->exec_size == 16)
deps[grf - first_grf + 1] = false;
}
}
}
/**
* Implements this workaround for the original 965:
*
* "[DevBW, DevCL] Implementation Restrictions: As the hardware does not
* check for post destination dependencies on this instruction, software
* must ensure that there is no destination hazard for the case of ‘write
* followed by a posted write’ shown in the following example.
*
* 1. mov r3 0
* 2. send r3.xy <rest of send instruction>
* 3. mov r2 r3
*
* Due to no post-destination dependency check on the ‘send’, the above
* code sequence could have two instructions (1 and 2) in flight at the
* same time that both consider ‘r3’ as the target of their final writes.
*/
void
fs_visitor::insert_gen4_pre_send_dependency_workarounds(bblock_t *block,
fs_inst *inst)
{
int write_len = regs_written(inst);
int first_write_grf = inst->dst.nr;
bool needs_dep[BRW_MAX_MRF(devinfo->gen)];
assert(write_len < (int)sizeof(needs_dep) - 1);
memset(needs_dep, false, sizeof(needs_dep));
memset(needs_dep, true, write_len);
clear_deps_for_inst_src(inst, needs_dep, first_write_grf, write_len);
/* Walk backwards looking for writes to registers we're writing which
* aren't read since being written. If we hit the start of the program,
* we assume that there are no outstanding dependencies on entry to the
* program.
*/
foreach_inst_in_block_reverse_starting_from(fs_inst, scan_inst, inst) {
/* If we hit control flow, assume that there *are* outstanding
* dependencies, and force their cleanup before our instruction.
*/
if (block->start() == scan_inst && block->num != 0) {
for (int i = 0; i < write_len; i++) {
if (needs_dep[i])
DEP_RESOLVE_MOV(fs_builder(this, block, inst),
first_write_grf + i);
}
return;
}
/* We insert our reads as late as possible on the assumption that any
* instruction but a MOV that might have left us an outstanding
* dependency has more latency than a MOV.
*/
if (scan_inst->dst.file == VGRF) {
for (unsigned i = 0; i < regs_written(scan_inst); i++) {
int reg = scan_inst->dst.nr + i;
if (reg >= first_write_grf &&
reg < first_write_grf + write_len &&
needs_dep[reg - first_write_grf]) {
DEP_RESOLVE_MOV(fs_builder(this, block, inst), reg);
needs_dep[reg - first_write_grf] = false;
if (scan_inst->exec_size == 16)
needs_dep[reg - first_write_grf + 1] = false;
}
}
}
/* Clear the flag for registers that actually got read (as expected). */
clear_deps_for_inst_src(scan_inst, needs_dep, first_write_grf, write_len);
/* Continue the loop only if we haven't resolved all the dependencies */
int i;
for (i = 0; i < write_len; i++) {
if (needs_dep[i])
break;
}
if (i == write_len)
return;
}
}
/**
* Implements this workaround for the original 965:
*
* "[DevBW, DevCL] Errata: A destination register from a send can not be
* used as a destination register until after it has been sourced by an
* instruction with a different destination register.
*/
void
fs_visitor::insert_gen4_post_send_dependency_workarounds(bblock_t *block, fs_inst *inst)
{
int write_len = regs_written(inst);
int first_write_grf = inst->dst.nr;
bool needs_dep[BRW_MAX_MRF(devinfo->gen)];
assert(write_len < (int)sizeof(needs_dep) - 1);
memset(needs_dep, false, sizeof(needs_dep));
memset(needs_dep, true, write_len);
/* Walk forwards looking for writes to registers we're writing which aren't
* read before being written.
*/
foreach_inst_in_block_starting_from(fs_inst, scan_inst, inst) {
/* If we hit control flow, force resolve all remaining dependencies. */
if (block->end() == scan_inst && block->num != cfg->num_blocks - 1) {
for (int i = 0; i < write_len; i++) {
if (needs_dep[i])
DEP_RESOLVE_MOV(fs_builder(this, block, scan_inst),
first_write_grf + i);
}
return;
}
/* Clear the flag for registers that actually got read (as expected). */
clear_deps_for_inst_src(scan_inst, needs_dep, first_write_grf, write_len);
/* We insert our reads as late as possible since they're reading the
* result of a SEND, which has massive latency.
*/
if (scan_inst->dst.file == VGRF &&
scan_inst->dst.nr >= first_write_grf &&
scan_inst->dst.nr < first_write_grf + write_len &&
needs_dep[scan_inst->dst.nr - first_write_grf]) {
DEP_RESOLVE_MOV(fs_builder(this, block, scan_inst),
scan_inst->dst.nr);
needs_dep[scan_inst->dst.nr - first_write_grf] = false;
}
/* Continue the loop only if we haven't resolved all the dependencies */
int i;
for (i = 0; i < write_len; i++) {
if (needs_dep[i])
break;
}
if (i == write_len)
return;
}
}
void
fs_visitor::insert_gen4_send_dependency_workarounds()
{
if (devinfo->gen != 4 || devinfo->is_g4x)
return;
bool progress = false;
foreach_block_and_inst(block, fs_inst, inst, cfg) {
if (inst->mlen != 0 && inst->dst.file == VGRF) {
insert_gen4_pre_send_dependency_workarounds(block, inst);
insert_gen4_post_send_dependency_workarounds(block, inst);
progress = true;
}
}
if (progress)
invalidate_live_intervals();
}
/**
* Turns the generic expression-style uniform pull constant load instruction
* into a hardware-specific series of instructions for loading a pull
* constant.
*
* The expression style allows the CSE pass before this to optimize out
* repeated loads from the same offset, and gives the pre-register-allocation
* scheduling full flexibility, while the conversion to native instructions
* allows the post-register-allocation scheduler the best information
* possible.
*
* Note that execution masking for setting up pull constant loads is special:
* the channels that need to be written are unrelated to the current execution
* mask, since a later instruction will use one of the result channels as a
* source operand for all 8 or 16 of its channels.
*/
void
fs_visitor::lower_uniform_pull_constant_loads()
{
foreach_block_and_inst (block, fs_inst, inst, cfg) {
if (inst->opcode != FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD)
continue;
if (devinfo->gen >= 7) {
const fs_builder ubld = fs_builder(this, block, inst).exec_all();
const fs_reg payload = ubld.group(8, 0).vgrf(BRW_REGISTER_TYPE_UD);
ubld.group(8, 0).MOV(payload,
retype(brw_vec8_grf(0, 0), BRW_REGISTER_TYPE_UD));
ubld.group(1, 0).MOV(component(payload, 2),
brw_imm_ud(inst->src[1].ud / 16));
inst->opcode = FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD_GEN7;
inst->src[1] = payload;
inst->header_size = 1;
inst->mlen = 1;
invalidate_live_intervals();
} else {
/* Before register allocation, we didn't tell the scheduler about the
* MRF we use. We know it's safe to use this MRF because nothing
* else does except for register spill/unspill, which generates and
* uses its MRF within a single IR instruction.
*/
inst->base_mrf = FIRST_PULL_LOAD_MRF(devinfo->gen) + 1;
inst->mlen = 1;
}
}
}
bool
fs_visitor::lower_load_payload()
{
bool progress = false;
foreach_block_and_inst_safe (block, fs_inst, inst, cfg) {
if (inst->opcode != SHADER_OPCODE_LOAD_PAYLOAD)
continue;
assert(inst->dst.file == MRF || inst->dst.file == VGRF);
assert(inst->saturate == false);
fs_reg dst = inst->dst;
/* Get rid of COMPR4. We'll add it back in if we need it */
if (dst.file == MRF)
dst.nr = dst.nr & ~BRW_MRF_COMPR4;
const fs_builder ibld(this, block, inst);
const fs_builder hbld = ibld.exec_all().group(8, 0);
for (uint8_t i = 0; i < inst->header_size; i++) {
if (inst->src[i].file != BAD_FILE) {
fs_reg mov_dst = retype(dst, BRW_REGISTER_TYPE_UD);
fs_reg mov_src = retype(inst->src[i], BRW_REGISTER_TYPE_UD);
hbld.MOV(mov_dst, mov_src);
}
dst = offset(dst, hbld, 1);
}
if (inst->dst.file == MRF && (inst->dst.nr & BRW_MRF_COMPR4) &&
inst->exec_size > 8) {
/* In this case, the payload portion of the LOAD_PAYLOAD isn't
* a straightforward copy. Instead, the result of the
* LOAD_PAYLOAD is treated as interleaved and the first four
* non-header sources are unpacked as:
*
* m + 0: r0
* m + 1: g0
* m + 2: b0
* m + 3: a0
* m + 4: r1
* m + 5: g1
* m + 6: b1
* m + 7: a1
*
* This is used for gen <= 5 fb writes.
*/
assert(inst->exec_size == 16);
assert(inst->header_size + 4 <= inst->sources);
for (uint8_t i = inst->header_size; i < inst->header_size + 4; i++) {
if (inst->src[i].file != BAD_FILE) {
if (devinfo->has_compr4) {
fs_reg compr4_dst = retype(dst, inst->src[i].type);
compr4_dst.nr |= BRW_MRF_COMPR4;
ibld.MOV(compr4_dst, inst->src[i]);
} else {
/* Platform doesn't have COMPR4. We have to fake it */
fs_reg mov_dst = retype(dst, inst->src[i].type);
ibld.half(0).MOV(mov_dst, half(inst->src[i], 0));
mov_dst.nr += 4;
ibld.half(1).MOV(mov_dst, half(inst->src[i], 1));
}
}
dst.nr++;
}
/* The loop above only ever incremented us through the first set
* of 4 registers. However, thanks to the magic of COMPR4, we
* actually wrote to the first 8 registers, so we need to take
* that into account now.
*/
dst.nr += 4;
/* The COMPR4 code took care of the first 4 sources. We'll let
* the regular path handle any remaining sources. Yes, we are
* modifying the instruction but we're about to delete it so
* this really doesn't hurt anything.
*/
inst->header_size += 4;
}
for (uint8_t i = inst->header_size; i < inst->sources; i++) {
if (inst->src[i].file != BAD_FILE)
ibld.MOV(retype(dst, inst->src[i].type), inst->src[i]);
dst = offset(dst, ibld, 1);
}
inst->remove(block);
progress = true;
}
if (progress)
invalidate_live_intervals();
return progress;
}
bool
fs_visitor::lower_integer_multiplication()
{
bool progress = false;
foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
const fs_builder ibld(this, block, inst);
if (inst->opcode == BRW_OPCODE_MUL) {
if (inst->dst.is_accumulator() ||
(inst->dst.type != BRW_REGISTER_TYPE_D &&
inst->dst.type != BRW_REGISTER_TYPE_UD))
continue;
/* Gen8's MUL instruction can do a 32-bit x 32-bit -> 32-bit
* operation directly, but CHV/BXT cannot.
*/
if (devinfo->gen >= 8 &&
!devinfo->is_cherryview && !gen_device_info_is_9lp(devinfo))
continue;
if (inst->src[1].file == IMM &&
inst->src[1].ud < (1 << 16)) {
/* The MUL instruction isn't commutative. On Gen <= 6, only the low
* 16-bits of src0 are read, and on Gen >= 7 only the low 16-bits of
* src1 are used.
*
* If multiplying by an immediate value that fits in 16-bits, do a
* single MUL instruction with that value in the proper location.
*/
if (devinfo->gen < 7) {
fs_reg imm(VGRF, alloc.allocate(dispatch_width / 8),
inst->dst.type);
ibld.MOV(imm, inst->src[1]);
ibld.MUL(inst->dst, imm, inst->src[0]);
} else {
const bool ud = (inst->src[1].type == BRW_REGISTER_TYPE_UD);
ibld.MUL(inst->dst, inst->src[0],
ud ? brw_imm_uw(inst->src[1].ud)
: brw_imm_w(inst->src[1].d));
}
} else {
/* Gen < 8 (and some Gen8+ low-power parts like Cherryview) cannot
* do 32-bit integer multiplication in one instruction, but instead
* must do a sequence (which actually calculates a 64-bit result):
*
* mul(8) acc0<1>D g3<8,8,1>D g4<8,8,1>D
* mach(8) null g3<8,8,1>D g4<8,8,1>D
* mov(8) g2<1>D acc0<8,8,1>D
*
* But on Gen > 6, the ability to use second accumulator register
* (acc1) for non-float data types was removed, preventing a simple
* implementation in SIMD16. A 16-channel result can be calculated by
* executing the three instructions twice in SIMD8, once with quarter
* control of 1Q for the first eight channels and again with 2Q for
* the second eight channels.
*
* Which accumulator register is implicitly accessed (by AccWrEnable
* for instance) is determined by the quarter control. Unfortunately
* Ivybridge (and presumably Baytrail) has a hardware bug in which an
* implicit accumulator access by an instruction with 2Q will access
* acc1 regardless of whether the data type is usable in acc1.
*
* Specifically, the 2Q mach(8) writes acc1 which does not exist for
* integer data types.
*
* Since we only want the low 32-bits of the result, we can do two
* 32-bit x 16-bit multiplies (like the mul and mach are doing), and
* adjust the high result and add them (like the mach is doing):
*
* mul(8) g7<1>D g3<8,8,1>D g4.0<8,8,1>UW
* mul(8) g8<1>D g3<8,8,1>D g4.1<8,8,1>UW
* shl(8) g9<1>D g8<8,8,1>D 16D
* add(8) g2<1>D g7<8,8,1>D g8<8,8,1>D
*
* We avoid the shl instruction by realizing that we only want to add
* the low 16-bits of the "high" result to the high 16-bits of the
* "low" result and using proper regioning on the add:
*
* mul(8) g7<1>D g3<8,8,1>D g4.0<16,8,2>UW
* mul(8) g8<1>D g3<8,8,1>D g4.1<16,8,2>UW
* add(8) g7.1<2>UW g7.1<16,8,2>UW g8<16,8,2>UW
*
* Since it does not use the (single) accumulator register, we can
* schedule multi-component multiplications much better.
*/
bool needs_mov = false;
fs_reg orig_dst = inst->dst;
fs_reg low = inst->dst;
if (orig_dst.is_null() || orig_dst.file == MRF ||
regions_overlap(inst->dst, inst->size_written,
inst->src[0], inst->size_read(0)) ||
regions_overlap(inst->dst, inst->size_written,
inst->src[1], inst->size_read(1))) {
needs_mov = true;
/* Get a new VGRF but keep the same stride as inst->dst */
low = fs_reg(VGRF, alloc.allocate(regs_written(inst)),
inst->dst.type);
low.stride = inst->dst.stride;
low.offset = inst->dst.offset % REG_SIZE;
}
/* Get a new VGRF but keep the same stride as inst->dst */
fs_reg high(VGRF, alloc.allocate(regs_written(inst)),
inst->dst.type);
high.stride = inst->dst.stride;
high.offset = inst->dst.offset % REG_SIZE;
if (devinfo->gen >= 7) {
if (inst->src[1].file == IMM) {
ibld.MUL(low, inst->src[0],
brw_imm_uw(inst->src[1].ud & 0xffff));
ibld.MUL(high, inst->src[0],
brw_imm_uw(inst->src[1].ud >> 16));
} else {
ibld.MUL(low, inst->src[0],
subscript(inst->src[1], BRW_REGISTER_TYPE_UW, 0));
ibld.MUL(high, inst->src[0],
subscript(inst->src[1], BRW_REGISTER_TYPE_UW, 1));
}
} else {
ibld.MUL(low, subscript(inst->src[0], BRW_REGISTER_TYPE_UW, 0),
inst->src[1]);
ibld.MUL(high, subscript(inst->src[0], BRW_REGISTER_TYPE_UW, 1),
inst->src[1]);
}
ibld.ADD(subscript(low, BRW_REGISTER_TYPE_UW, 1),
subscript(low, BRW_REGISTER_TYPE_UW, 1),
subscript(high, BRW_REGISTER_TYPE_UW, 0));
if (needs_mov || inst->conditional_mod) {
set_condmod(inst->conditional_mod,
ibld.MOV(orig_dst, low));
}
}
} else if (inst->opcode == SHADER_OPCODE_MULH) {
/* Should have been lowered to 8-wide. */
assert(inst->exec_size <= get_lowered_simd_width(devinfo, inst));
const fs_reg acc = retype(brw_acc_reg(inst->exec_size),
inst->dst.type);
fs_inst *mul = ibld.MUL(acc, inst->src[0], inst->src[1]);
fs_inst *mach = ibld.MACH(inst->dst, inst->src[0], inst->src[1]);
if (devinfo->gen >= 8) {
/* Until Gen8, integer multiplies read 32-bits from one source,
* and 16-bits from the other, and relying on the MACH instruction
* to generate the high bits of the result.
*
* On Gen8, the multiply instruction does a full 32x32-bit
* multiply, but in order to do a 64-bit multiply we can simulate
* the previous behavior and then use a MACH instruction.
*
* FINISHME: Don't use source modifiers on src1.
*/
assert(mul->src[1].type == BRW_REGISTER_TYPE_D ||
mul->src[1].type == BRW_REGISTER_TYPE_UD);
mul->src[1].type = BRW_REGISTER_TYPE_UW;
mul->src[1].stride *= 2;
} else if (devinfo->gen == 7 && !devinfo->is_haswell &&
inst->group > 0) {
/* Among other things the quarter control bits influence which
* accumulator register is used by the hardware for instructions
* that access the accumulator implicitly (e.g. MACH). A
* second-half instruction would normally map to acc1, which
* doesn't exist on Gen7 and up (the hardware does emulate it for
* floating-point instructions *only* by taking advantage of the
* extra precision of acc0 not normally used for floating point
* arithmetic).
*
* HSW and up are careful enough not to try to access an
* accumulator register that doesn't exist, but on earlier Gen7
* hardware we need to make sure that the quarter control bits are
* zero to avoid non-deterministic behaviour and emit an extra MOV
* to get the result masked correctly according to the current
* channel enables.
*/
mach->group = 0;
mach->force_writemask_all = true;
mach->dst = ibld.vgrf(inst->dst.type);
ibld.MOV(inst->dst, mach->dst);
}
} else {
continue;
}
inst->remove(block);
progress = true;
}
if (progress)
invalidate_live_intervals();
return progress;
}
bool
fs_visitor::lower_minmax()
{
assert(devinfo->gen < 6);
bool progress = false;
foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
const fs_builder ibld(this, block, inst);
if (inst->opcode == BRW_OPCODE_SEL &&
inst->predicate == BRW_PREDICATE_NONE) {
/* FIXME: Using CMP doesn't preserve the NaN propagation semantics of
* the original SEL.L/GE instruction
*/
ibld.CMP(ibld.null_reg_d(), inst->src[0], inst->src[1],
inst->conditional_mod);
inst->predicate = BRW_PREDICATE_NORMAL;
inst->conditional_mod = BRW_CONDITIONAL_NONE;
progress = true;
}
}
if (progress)
invalidate_live_intervals();
return progress;
}
static void
setup_color_payload(const fs_builder &bld, const brw_wm_prog_key *key,
fs_reg *dst, fs_reg color, unsigned components)
{
if (key->clamp_fragment_color) {
fs_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_F, 4);
assert(color.type == BRW_REGISTER_TYPE_F);
for (unsigned i = 0; i < components; i++)
set_saturate(true,
bld.MOV(offset(tmp, bld, i), offset(color, bld, i)));
color = tmp;
}
for (unsigned i = 0; i < components; i++)
dst[i] = offset(color, bld, i);
}
static void
lower_fb_write_logical_send(const fs_builder &bld, fs_inst *inst,
const struct brw_wm_prog_data *prog_data,
const brw_wm_prog_key *key,
const fs_visitor::thread_payload &payload)
{
assert(inst->src[FB_WRITE_LOGICAL_SRC_COMPONENTS].file == IMM);
const gen_device_info *devinfo = bld.shader->devinfo;
const fs_reg &color0 = inst->src[FB_WRITE_LOGICAL_SRC_COLOR0];
const fs_reg &color1 = inst->src[FB_WRITE_LOGICAL_SRC_COLOR1];
const fs_reg &src0_alpha = inst->src[FB_WRITE_LOGICAL_SRC_SRC0_ALPHA];
const fs_reg &src_depth = inst->src[FB_WRITE_LOGICAL_SRC_SRC_DEPTH];
const fs_reg &dst_depth = inst->src[FB_WRITE_LOGICAL_SRC_DST_DEPTH];
const fs_reg &src_stencil = inst->src[FB_WRITE_LOGICAL_SRC_SRC_STENCIL];
fs_reg sample_mask = inst->src[FB_WRITE_LOGICAL_SRC_OMASK];
const unsigned components =
inst->src[FB_WRITE_LOGICAL_SRC_COMPONENTS].ud;
/* We can potentially have a message length of up to 15, so we have to set
* base_mrf to either 0 or 1 in order to fit in m0..m15.
*/
fs_reg sources[15];
int header_size = 2, payload_header_size;
unsigned length = 0;
/* From the Sandy Bridge PRM, volume 4, page 198:
*
* "Dispatched Pixel Enables. One bit per pixel indicating
* which pixels were originally enabled when the thread was
* dispatched. This field is only required for the end-of-
* thread message and on all dual-source messages."
*/
if (devinfo->gen >= 6 &&
(devinfo->is_haswell || devinfo->gen >= 8 || !prog_data->uses_kill) &&
color1.file == BAD_FILE &&
key->nr_color_regions == 1) {
header_size = 0;
}
if (header_size != 0) {
assert(header_size == 2);
/* Allocate 2 registers for a header */
length += 2;
}
if (payload.aa_dest_stencil_reg) {
sources[length] = fs_reg(VGRF, bld.shader->alloc.allocate(1));
bld.group(8, 0).exec_all().annotate("FB write stencil/AA alpha")
.MOV(sources[length],
fs_reg(brw_vec8_grf(payload.aa_dest_stencil_reg, 0)));
length++;
}
if (sample_mask.file != BAD_FILE) {
sources[length] = fs_reg(VGRF, bld.shader->alloc.allocate(1),
BRW_REGISTER_TYPE_UD);
/* Hand over gl_SampleMask. Only the lower 16 bits of each channel are
* relevant. Since it's unsigned single words one vgrf is always
* 16-wide, but only the lower or higher 8 channels will be used by the
* hardware when doing a SIMD8 write depending on whether we have
* selected the subspans for the first or second half respectively.
*/
assert(sample_mask.file != BAD_FILE && type_sz(sample_mask.type) == 4);
sample_mask.type = BRW_REGISTER_TYPE_UW;
sample_mask.stride *= 2;
bld.exec_all().annotate("FB write oMask")
.MOV(horiz_offset(retype(sources[length], BRW_REGISTER_TYPE_UW),
inst->group),
sample_mask);
length++;
}
payload_header_size = length;
if (src0_alpha.file != BAD_FILE) {
/* FIXME: This is being passed at the wrong location in the payload and
* doesn't work when gl_SampleMask and MRTs are used simultaneously.
* It's supposed to be immediately before oMask but there seems to be no
* reasonable way to pass them in the correct order because LOAD_PAYLOAD
* requires header sources to form a contiguous segment at the beginning
* of the message and src0_alpha has per-channel semantics.
*/
setup_color_payload(bld, key, &sources[length], src0_alpha, 1);
length++;
} else if (key->replicate_alpha && inst->target != 0) {
/* Handle the case when fragment shader doesn't write to draw buffer
* zero. No need to call setup_color_payload() for src0_alpha because
* alpha value will be undefined.
*/
length++;
}
setup_color_payload(bld, key, &sources[length], color0, components);
length += 4;
if (color1.file != BAD_FILE) {
setup_color_payload(bld, key, &sources[length], color1, components);
length += 4;
}
if (src_depth.file != BAD_FILE) {
sources[length] = src_depth;
length++;
}
if (dst_depth.file != BAD_FILE) {
sources[length] = dst_depth;
length++;
}
if (src_stencil.file != BAD_FILE) {
assert(devinfo->gen >= 9);
assert(bld.dispatch_width() != 16);
/* XXX: src_stencil is only available on gen9+. dst_depth is never
* available on gen9+. As such it's impossible to have both enabled at the
* same time and therefore length cannot overrun the array.
*/
assert(length < 15);
sources[length] = bld.vgrf(BRW_REGISTER_TYPE_UD);
bld.exec_all().annotate("FB write OS")
.MOV(retype(sources[length], BRW_REGISTER_TYPE_UB),
subscript(src_stencil, BRW_REGISTER_TYPE_UB, 0));
length++;
}
fs_inst *load;
if (devinfo->gen >= 7) {
/* Send from the GRF */
fs_reg payload = fs_reg(VGRF, -1, BRW_REGISTER_TYPE_F);
load = bld.LOAD_PAYLOAD(payload, sources, length, payload_header_size);
payload.nr = bld.shader->alloc.allocate(regs_written(load));
load->dst = payload;
inst->src[0] = payload;
inst->resize_sources(1);
} else {
/* Send from the MRF */
load = bld.LOAD_PAYLOAD(fs_reg(MRF, 1, BRW_REGISTER_TYPE_F),
sources, length, payload_header_size);
/* On pre-SNB, we have to interlace the color values. LOAD_PAYLOAD
* will do this for us if we just give it a COMPR4 destination.
*/
if (devinfo->gen < 6 && bld.dispatch_width() == 16)
load->dst.nr |= BRW_MRF_COMPR4;
inst->resize_sources(0);
inst->base_mrf = 1;
}
inst->opcode = FS_OPCODE_FB_WRITE;
inst->mlen = regs_written(load);
inst->header_size = header_size;
}
static void
lower_fb_read_logical_send(const fs_builder &bld, fs_inst *inst)
{
const fs_builder &ubld = bld.exec_all();
const unsigned length = 2;
const fs_reg header = ubld.group(8, 0).vgrf(BRW_REGISTER_TYPE_UD, length);
ubld.group(16, 0)
.MOV(header, retype(brw_vec8_grf(0, 0), BRW_REGISTER_TYPE_UD));
inst->resize_sources(1);
inst->src[0] = header;
inst->opcode = FS_OPCODE_FB_READ;
inst->mlen = length;
inst->header_size = length;
}
static void
lower_sampler_logical_send_gen4(const fs_builder &bld, fs_inst *inst, opcode op,
const fs_reg &coordinate,
const fs_reg &shadow_c,
const fs_reg &lod, const fs_reg &lod2,
const fs_reg &surface,
const fs_reg &sampler,
unsigned coord_components,
unsigned grad_components)
{
const bool has_lod = (op == SHADER_OPCODE_TXL || op == FS_OPCODE_TXB ||
op == SHADER_OPCODE_TXF || op == SHADER_OPCODE_TXS);
fs_reg msg_begin(MRF, 1, BRW_REGISTER_TYPE_F);
fs_reg msg_end = msg_begin;
/* g0 header. */
msg_end = offset(msg_end, bld.group(8, 0), 1);
for (unsigned i = 0; i < coord_components; i++)
bld.MOV(retype(offset(msg_end, bld, i), coordinate.type),
offset(coordinate, bld, i));
msg_end = offset(msg_end, bld, coord_components);
/* Messages other than SAMPLE and RESINFO in SIMD16 and TXD in SIMD8
* require all three components to be present and zero if they are unused.
*/
if (coord_components > 0 &&
(has_lod || shadow_c.file != BAD_FILE ||
(op == SHADER_OPCODE_TEX && bld.dispatch_width() == 8))) {
for (unsigned i = coord_components; i < 3; i++)
bld.MOV(offset(msg_end, bld, i), brw_imm_f(0.0f));
msg_end = offset(msg_end, bld, 3 - coord_components);
}
if (op == SHADER_OPCODE_TXD) {
/* TXD unsupported in SIMD16 mode. */
assert(bld.dispatch_width() == 8);
/* the slots for u and v are always present, but r is optional */
if (coord_components < 2)
msg_end = offset(msg_end, bld, 2 - coord_components);
/* P = u, v, r
* dPdx = dudx, dvdx, drdx
* dPdy = dudy, dvdy, drdy
*
* 1-arg: Does not exist.
*
* 2-arg: dudx dvdx dudy dvdy
* dPdx.x dPdx.y dPdy.x dPdy.y
* m4 m5 m6 m7
*
* 3-arg: dudx dvdx drdx dudy dvdy drdy
* dPdx.x dPdx.y dPdx.z dPdy.x dPdy.y dPdy.z
* m5 m6 m7 m8 m9 m10
*/
for (unsigned i = 0; i < grad_components; i++)
bld.MOV(offset(msg_end, bld, i), offset(lod, bld, i));
msg_end = offset(msg_end, bld, MAX2(grad_components, 2));
for (unsigned i = 0; i < grad_components; i++)
bld.MOV(offset(msg_end, bld, i), offset(lod2, bld, i));
msg_end = offset(msg_end, bld, MAX2(grad_components, 2));
}
if (has_lod) {
/* Bias/LOD with shadow comparator is unsupported in SIMD16 -- *Without*
* shadow comparator (including RESINFO) it's unsupported in SIMD8 mode.
*/
assert(shadow_c.file != BAD_FILE ? bld.dispatch_width() == 8 :
bld.dispatch_width() == 16);
const brw_reg_type type =
(op == SHADER_OPCODE_TXF || op == SHADER_OPCODE_TXS ?
BRW_REGISTER_TYPE_UD : BRW_REGISTER_TYPE_F);
bld.MOV(retype(msg_end, type), lod);
msg_end = offset(msg_end, bld, 1);
}
if (shadow_c.file != BAD_FILE) {
if (op == SHADER_OPCODE_TEX && bld.dispatch_width() == 8) {
/* There's no plain shadow compare message, so we use shadow
* compare with a bias of 0.0.
*/
bld.MOV(msg_end, brw_imm_f(0.0f));
msg_end = offset(msg_end, bld, 1);
}
bld.MOV(msg_end, shadow_c);
msg_end = offset(msg_end, bld, 1);
}
inst->opcode = op;
inst->src[0] = reg_undef;
inst->src[1] = surface;
inst->src[2] = sampler;
inst->resize_sources(3);
inst->base_mrf = msg_begin.nr;
inst->mlen = msg_end.nr - msg_begin.nr;
inst->header_size = 1;
}
static void
lower_sampler_logical_send_gen5(const fs_builder &bld, fs_inst *inst, opcode op,
const fs_reg &coordinate,
const fs_reg &shadow_c,
const fs_reg &lod, const fs_reg &lod2,
const fs_reg &sample_index,
const fs_reg &surface,
const fs_reg &sampler,
unsigned coord_components,
unsigned grad_components)
{
fs_reg message(MRF, 2, BRW_REGISTER_TYPE_F);
fs_reg msg_coords = message;
unsigned header_size = 0;
if (inst->offset != 0) {
/* The offsets set up by the visitor are in the m1 header, so we can't
* go headerless.
*/
header_size = 1;
message.nr--;
}
for (unsigned i = 0; i < coord_components; i++)
bld.MOV(retype(offset(msg_coords, bld, i), coordinate.type),
offset(coordinate, bld, i));
fs_reg msg_end = offset(msg_coords, bld, coord_components);
fs_reg msg_lod = offset(msg_coords, bld, 4);
if (shadow_c.file != BAD_FILE) {
fs_reg msg_shadow = msg_lod;
bld.MOV(msg_shadow, shadow_c);
msg_lod = offset(msg_shadow, bld, 1);
msg_end = msg_lod;
}
switch (op) {
case SHADER_OPCODE_TXL:
case FS_OPCODE_TXB:
bld.MOV(msg_lod, lod);
msg_end = offset(msg_lod, bld, 1);
break;
case SHADER_OPCODE_TXD:
/**
* P = u, v, r
* dPdx = dudx, dvdx, drdx
* dPdy = dudy, dvdy, drdy
*
* Load up these values:
* - dudx dudy dvdx dvdy drdx drdy
* - dPdx.x dPdy.x dPdx.y dPdy.y dPdx.z dPdy.z
*/
msg_end = msg_lod;
for (unsigned i = 0; i < grad_components; i++) {
bld.MOV(msg_end, offset(lod, bld, i));
msg_end = offset(msg_end, bld, 1);
bld.MOV(msg_end, offset(lod2, bld, i));
msg_end = offset(msg_end, bld, 1);
}
break;
case SHADER_OPCODE_TXS:
msg_lod = retype(msg_end, BRW_REGISTER_TYPE_UD);
bld.MOV(msg_lod, lod);
msg_end = offset(msg_lod, bld, 1);
break;
case SHADER_OPCODE_TXF:
msg_lod = offset(msg_coords, bld, 3);
bld.MOV(retype(msg_lod, BRW_REGISTER_TYPE_UD), lod);
msg_end = offset(msg_lod, bld, 1);
break;
case SHADER_OPCODE_TXF_CMS:
msg_lod = offset(msg_coords, bld, 3);
/* lod */
bld.MOV(retype(msg_lod, BRW_REGISTER_TYPE_UD), brw_imm_ud(0u));
/* sample index */
bld.MOV(retype(offset(msg_lod, bld, 1), BRW_REGISTER_TYPE_UD), sample_index);
msg_end = offset(msg_lod, bld, 2);
break;
default:
break;
}
inst->opcode = op;
inst->src[0] = reg_undef;
inst->src[1] = surface;
inst->src[2] = sampler;
inst->resize_sources(3);
inst->base_mrf = message.nr;
inst->mlen = msg_end.nr - message.nr;
inst->header_size = header_size;
/* Message length > MAX_SAMPLER_MESSAGE_SIZE disallowed by hardware. */
assert(inst->mlen <= MAX_SAMPLER_MESSAGE_SIZE);
}
static bool
is_high_sampler(const struct gen_device_info *devinfo, const fs_reg &sampler)
{
if (devinfo->gen < 8 && !devinfo->is_haswell)
return false;
return sampler.file != IMM || sampler.ud >= 16;
}
static void
lower_sampler_logical_send_gen7(const fs_builder &bld, fs_inst *inst, opcode op,
const fs_reg &coordinate,
const fs_reg &shadow_c,
fs_reg lod, const fs_reg &lod2,
const fs_reg &sample_index,
const fs_reg &mcs,
const fs_reg &surface,
const fs_reg &sampler,
const fs_reg &tg4_offset,
unsigned coord_components,
unsigned grad_components)
{
const gen_device_info *devinfo = bld.shader->devinfo;
unsigned reg_width = bld.dispatch_width() / 8;
unsigned header_size = 0, length = 0;
fs_reg sources[MAX_SAMPLER_MESSAGE_SIZE];
for (unsigned i = 0; i < ARRAY_SIZE(sources); i++)
sources[i] = bld.vgrf(BRW_REGISTER_TYPE_F);
if (op == SHADER_OPCODE_TG4 || op == SHADER_OPCODE_TG4_OFFSET ||
inst->offset != 0 || inst->eot ||
op == SHADER_OPCODE_SAMPLEINFO ||
is_high_sampler(devinfo, sampler)) {
/* For general texture offsets (no txf workaround), we need a header to
* put them in.
*
* TG4 needs to place its channel select in the header, for interaction
* with ARB_texture_swizzle. The sampler index is only 4-bits, so for
* larger sampler numbers we need to offset the Sampler State Pointer in
* the header.
*/
fs_reg header = retype(sources[0], BRW_REGISTER_TYPE_UD);
header_size = 1;
length++;
/* If we're requesting fewer than four channels worth of response,
* and we have an explicit header, we need to set up the sampler
* writemask. It's reversed from normal: 1 means "don't write".
*/
if (!inst->eot && regs_written(inst) != 4 * reg_width) {
assert(regs_written(inst) % reg_width == 0);
unsigned mask = ~((1 << (regs_written(inst) / reg_width)) - 1) & 0xf;
inst->offset |= mask << 12;
}
/* Build the actual header */
const fs_builder ubld = bld.exec_all().group(8, 0);
const fs_builder ubld1 = ubld.group(1, 0);
ubld.MOV(header, retype(brw_vec8_grf(0, 0), BRW_REGISTER_TYPE_UD));
if (inst->offset) {
ubld1.MOV(component(header, 2), brw_imm_ud(inst->offset));
} else if (bld.shader->stage != MESA_SHADER_VERTEX &&
bld.shader->stage != MESA_SHADER_FRAGMENT) {
/* The vertex and fragment stages have g0.2 set to 0, so
* header0.2 is 0 when g0 is copied. Other stages may not, so we
* must set it to 0 to avoid setting undesirable bits in the
* message.
*/
ubld1.MOV(component(header, 2), brw_imm_ud(0));
}
if (is_high_sampler(devinfo, sampler)) {
if (sampler.file == BRW_IMMEDIATE_VALUE) {
assert(sampler.ud >= 16);
const int sampler_state_size = 16; /* 16 bytes */
ubld1.ADD(component(header, 3),
retype(brw_vec1_grf(0, 3), BRW_REGISTER_TYPE_UD),
brw_imm_ud(16 * (sampler.ud / 16) * sampler_state_size));
} else {
fs_reg tmp = ubld1.vgrf(BRW_REGISTER_TYPE_UD);
ubld1.AND(tmp, sampler, brw_imm_ud(0x0f0));
ubld1.SHL(tmp, tmp, brw_imm_ud(4));
ubld1.ADD(component(header, 3),
retype(brw_vec1_grf(0, 3), BRW_REGISTER_TYPE_UD),
tmp);
}
}
}
if (shadow_c.file != BAD_FILE) {
bld.MOV(sources[length], shadow_c);
length++;
}
bool coordinate_done = false;
/* Set up the LOD info */
switch (op) {
case FS_OPCODE_TXB:
case SHADER_OPCODE_TXL:
if (devinfo->gen >= 9 && op == SHADER_OPCODE_TXL && lod.is_zero()) {
op = SHADER_OPCODE_TXL_LZ;
break;
}
bld.MOV(sources[length], lod);
length++;
break;
case SHADER_OPCODE_TXD:
/* TXD should have been lowered in SIMD16 mode. */
assert(bld.dispatch_width() == 8);
/* Load dPdx and the coordinate together:
* [hdr], [ref], x, dPdx.x, dPdy.x, y, dPdx.y, dPdy.y, z, dPdx.z, dPdy.z
*/
for (unsigned i = 0; i < coord_components; i++) {
bld.MOV(sources[length++], offset(coordinate, bld, i));
/* For cube map array, the coordinate is (u,v,r,ai) but there are
* only derivatives for (u, v, r).
*/
if (i < grad_components) {
bld.MOV(sources[length++], offset(lod, bld, i));
bld.MOV(sources[length++], offset(lod2, bld, i));
}
}
coordinate_done = true;
break;
case SHADER_OPCODE_TXS:
bld.MOV(retype(sources[length], BRW_REGISTER_TYPE_UD), lod);
length++;
break;
case SHADER_OPCODE_TXF:
/* Unfortunately, the parameters for LD are intermixed: u, lod, v, r.
* On Gen9 they are u, v, lod, r
*/
bld.MOV(retype(sources[length++], BRW_REGISTER_TYPE_D), coordinate);
if (devinfo->gen >= 9) {
if (coord_components >= 2) {
bld.MOV(retype(sources[length], BRW_REGISTER_TYPE_D),
offset(coordinate, bld, 1));
} else {
sources[length] = brw_imm_d(0);
}
length++;
}
if (devinfo->gen >= 9 && lod.is_zero()) {
op = SHADER_OPCODE_TXF_LZ;
} else {
bld.MOV(retype(sources[length], BRW_REGISTER_TYPE_D), lod);
length++;
}
for (unsigned i = devinfo->gen >= 9 ? 2 : 1; i < coord_components; i++)
bld.MOV(retype(sources[length++], BRW_REGISTER_TYPE_D),
offset(coordinate, bld, i));
coordinate_done = true;
break;
case SHADER_OPCODE_TXF_CMS:
case SHADER_OPCODE_TXF_CMS_W:
case SHADER_OPCODE_TXF_UMS:
case SHADER_OPCODE_TXF_MCS:
if (op == SHADER_OPCODE_TXF_UMS ||
op == SHADER_OPCODE_TXF_CMS ||
op == SHADER_OPCODE_TXF_CMS_W) {
bld.MOV(retype(sources[length], BRW_REGISTER_TYPE_UD), sample_index);
length++;
}
if (op == SHADER_OPCODE_TXF_CMS || op == SHADER_OPCODE_TXF_CMS_W) {
/* Data from the multisample control surface. */
bld.MOV(retype(sources[length], BRW_REGISTER_TYPE_UD), mcs);
length++;
/* On Gen9+ we'll use ld2dms_w instead which has two registers for
* the MCS data.
*/
if (op == SHADER_OPCODE_TXF_CMS_W) {
bld.MOV(retype(sources[length], BRW_REGISTER_TYPE_UD),
mcs.file == IMM ?
mcs :
offset(mcs, bld, 1));
length++;
}
}
/* There is no offsetting for this message; just copy in the integer
* texture coordinates.
*/
for (unsigned i = 0; i < coord_components; i++)
bld.MOV(retype(sources[length++], BRW_REGISTER_TYPE_D),
offset(coordinate, bld, i));
coordinate_done = true;
break;
case SHADER_OPCODE_TG4_OFFSET:
/* More crazy intermixing */
for (unsigned i = 0; i < 2; i++) /* u, v */
bld.MOV(sources[length++], offset(coordinate, bld, i));
for (unsigned i = 0; i < 2; i++) /* offu, offv */
bld.MOV(retype(sources[length++], BRW_REGISTER_TYPE_D),
offset(tg4_offset, bld, i));
if (coord_components == 3) /* r if present */
bld.MOV(sources[length++], offset(coordinate, bld, 2));
coordinate_done = true;
break;
default:
break;
}
/* Set up the coordinate (except for cases where it was done above) */
if (!coordinate_done) {
for (unsigned i = 0; i < coord_components; i++)
bld.MOV(sources[length++], offset(coordinate, bld, i));
}
int mlen;
if (reg_width == 2)
mlen = length * reg_width - header_size;
else
mlen = length * reg_width;
const fs_reg src_payload = fs_reg(VGRF, bld.shader->alloc.allocate(mlen),
BRW_REGISTER_TYPE_F);
bld.LOAD_PAYLOAD(src_payload, sources, length, header_size);
/* Generate the SEND. */
inst->opcode = op;
inst->src[0] = src_payload;
inst->src[1] = surface;
inst->src[2] = sampler;
inst->resize_sources(3);
inst->mlen = mlen;
inst->header_size = header_size;
/* Message length > MAX_SAMPLER_MESSAGE_SIZE disallowed by hardware. */
assert(inst->mlen <= MAX_SAMPLER_MESSAGE_SIZE);
}
static void
lower_sampler_logical_send(const fs_builder &bld, fs_inst *inst, opcode op)
{
const gen_device_info *devinfo = bld.shader->devinfo;
const fs_reg &coordinate = inst->src[TEX_LOGICAL_SRC_COORDINATE];
const fs_reg &shadow_c = inst->src[TEX_LOGICAL_SRC_SHADOW_C];
const fs_reg &lod = inst->src[TEX_LOGICAL_SRC_LOD];
const fs_reg &lod2 = inst->src[TEX_LOGICAL_SRC_LOD2];
const fs_reg &sample_index = inst->src[TEX_LOGICAL_SRC_SAMPLE_INDEX];
const fs_reg &mcs = inst->src[TEX_LOGICAL_SRC_MCS];
const fs_reg &surface = inst->src[TEX_LOGICAL_SRC_SURFACE];
const fs_reg &sampler = inst->src[TEX_LOGICAL_SRC_SAMPLER];
const fs_reg &tg4_offset = inst->src[TEX_LOGICAL_SRC_TG4_OFFSET];
assert(inst->src[TEX_LOGICAL_SRC_COORD_COMPONENTS].file == IMM);
const unsigned coord_components = inst->src[TEX_LOGICAL_SRC_COORD_COMPONENTS].ud;
assert(inst->src[TEX_LOGICAL_SRC_GRAD_COMPONENTS].file == IMM);
const unsigned grad_components = inst->src[TEX_LOGICAL_SRC_GRAD_COMPONENTS].ud;
if (devinfo->gen >= 7) {
lower_sampler_logical_send_gen7(bld, inst, op, coordinate,
shadow_c, lod, lod2, sample_index,
mcs, surface, sampler, tg4_offset,
coord_components, grad_components);
} else if (devinfo->gen >= 5) {
lower_sampler_logical_send_gen5(bld, inst, op, coordinate,
shadow_c, lod, lod2, sample_index,
surface, sampler,
coord_components, grad_components);
} else {
lower_sampler_logical_send_gen4(bld, inst, op, coordinate,
shadow_c, lod, lod2,
surface, sampler,
coord_components, grad_components);
}
}
/**
* Initialize the header present in some typed and untyped surface
* messages.
*/
static fs_reg
emit_surface_header(const fs_builder &bld, const fs_reg &sample_mask)
{
fs_builder ubld = bld.exec_all().group(8, 0);
const fs_reg dst = ubld.vgrf(BRW_REGISTER_TYPE_UD);
ubld.MOV(dst, brw_imm_d(0));
ubld.group(1, 0).MOV(component(dst, 7), sample_mask);
return dst;
}
static void
lower_surface_logical_send(const fs_builder &bld, fs_inst *inst, opcode op,
const fs_reg &sample_mask)
{
/* Get the logical send arguments. */
const fs_reg &addr = inst->src[0];
const fs_reg &src = inst->src[1];
const fs_reg &surface = inst->src[2];
const UNUSED fs_reg &dims = inst->src[3];
const fs_reg &arg = inst->src[4];
/* Calculate the total number of components of the payload. */
const unsigned addr_sz = inst->components_read(0);
const unsigned src_sz = inst->components_read(1);
const unsigned header_sz = (sample_mask.file == BAD_FILE ? 0 : 1);
const unsigned sz = header_sz + addr_sz + src_sz;
/* Allocate space for the payload. */
fs_reg *const components = new fs_reg[sz];
const fs_reg payload = bld.vgrf(BRW_REGISTER_TYPE_UD, sz);
unsigned n = 0;
/* Construct the payload. */
if (header_sz)
components[n++] = emit_surface_header(bld, sample_mask);
for (unsigned i = 0; i < addr_sz; i++)
components[n++] = offset(addr, bld, i);
for (unsigned i = 0; i < src_sz; i++)
components[n++] = offset(src, bld, i);
bld.LOAD_PAYLOAD(payload, components, sz, header_sz);
/* Update the original instruction. */
inst->opcode = op;
inst->mlen = header_sz + (addr_sz + src_sz) * inst->exec_size / 8;
inst->header_size = header_sz;
inst->src[0] = payload;
inst->src[1] = surface;
inst->src[2] = arg;
inst->resize_sources(3);
delete[] components;
}
static void
lower_varying_pull_constant_logical_send(const fs_builder &bld, fs_inst *inst)
{
const gen_device_info *devinfo = bld.shader->devinfo;
if (devinfo->gen >= 7) {
/* We are switching the instruction from an ALU-like instruction to a
* send-from-grf instruction. Since sends can't handle strides or
* source modifiers, we have to make a copy of the offset source.
*/
fs_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_UD);
bld.MOV(tmp, inst->src[1]);
inst->src[1] = tmp;
inst->opcode = FS_OPCODE_VARYING_PULL_CONSTANT_LOAD_GEN7;
} else {
const fs_reg payload(MRF, FIRST_PULL_LOAD_MRF(devinfo->gen),
BRW_REGISTER_TYPE_UD);
bld.MOV(byte_offset(payload, REG_SIZE), inst->src[1]);
inst->opcode = FS_OPCODE_VARYING_PULL_CONSTANT_LOAD_GEN4;
inst->resize_sources(1);
inst->base_mrf = payload.nr;
inst->header_size = 1;
inst->mlen = 1 + inst->exec_size / 8;
}
}
static void
lower_math_logical_send(const fs_builder &bld, fs_inst *inst)
{
assert(bld.shader->devinfo->gen < 6);
inst->base_mrf = 2;
inst->mlen = inst->sources * inst->exec_size / 8;
if (inst->sources > 1) {
/* From the Ironlake PRM, Volume 4, Part 1, Section 6.1.13
* "Message Payload":
*
* "Operand0[7]. For the INT DIV functions, this operand is the
* denominator."
* ...
* "Operand1[7]. For the INT DIV functions, this operand is the
* numerator."
*/
const bool is_int_div = inst->opcode != SHADER_OPCODE_POW;
const fs_reg src0 = is_int_div ? inst->src[1] : inst->src[0];
const fs_reg src1 = is_int_div ? inst->src[0] : inst->src[1];
inst->resize_sources(1);
inst->src[0] = src0;
assert(inst->exec_size == 8);
bld.MOV(fs_reg(MRF, inst->base_mrf + 1, src1.type), src1);
}
}
bool
fs_visitor::lower_logical_sends()
{
bool progress = false;
foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
const fs_builder ibld(this, block, inst);
switch (inst->opcode) {
case FS_OPCODE_FB_WRITE_LOGICAL:
assert(stage == MESA_SHADER_FRAGMENT);
lower_fb_write_logical_send(ibld, inst,
brw_wm_prog_data(prog_data),
(const brw_wm_prog_key *)key,
payload);
break;
case FS_OPCODE_FB_READ_LOGICAL:
lower_fb_read_logical_send(ibld, inst);
break;
case SHADER_OPCODE_TEX_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TEX);
break;
case SHADER_OPCODE_TXD_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TXD);
break;
case SHADER_OPCODE_TXF_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TXF);
break;
case SHADER_OPCODE_TXL_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TXL);
break;
case SHADER_OPCODE_TXS_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TXS);
break;
case FS_OPCODE_TXB_LOGICAL:
lower_sampler_logical_send(ibld, inst, FS_OPCODE_TXB);
break;
case SHADER_OPCODE_TXF_CMS_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TXF_CMS);
break;
case SHADER_OPCODE_TXF_CMS_W_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TXF_CMS_W);
break;
case SHADER_OPCODE_TXF_UMS_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TXF_UMS);
break;
case SHADER_OPCODE_TXF_MCS_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TXF_MCS);
break;
case SHADER_OPCODE_LOD_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_LOD);
break;
case SHADER_OPCODE_TG4_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TG4);
break;
case SHADER_OPCODE_TG4_OFFSET_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_TG4_OFFSET);
break;
case SHADER_OPCODE_SAMPLEINFO_LOGICAL:
lower_sampler_logical_send(ibld, inst, SHADER_OPCODE_SAMPLEINFO);
break;
case SHADER_OPCODE_UNTYPED_SURFACE_READ_LOGICAL:
lower_surface_logical_send(ibld, inst,
SHADER_OPCODE_UNTYPED_SURFACE_READ,
fs_reg());
break;
case SHADER_OPCODE_UNTYPED_SURFACE_WRITE_LOGICAL:
lower_surface_logical_send(ibld, inst,
SHADER_OPCODE_UNTYPED_SURFACE_WRITE,
ibld.sample_mask_reg());
break;
case SHADER_OPCODE_BYTE_SCATTERED_READ_LOGICAL:
lower_surface_logical_send(ibld, inst,
SHADER_OPCODE_BYTE_SCATTERED_READ,
fs_reg());
break;
case SHADER_OPCODE_BYTE_SCATTERED_WRITE_LOGICAL:
lower_surface_logical_send(ibld, inst,
SHADER_OPCODE_BYTE_SCATTERED_WRITE,
ibld.sample_mask_reg());
break;
case SHADER_OPCODE_UNTYPED_ATOMIC_LOGICAL:
lower_surface_logical_send(ibld, inst,
SHADER_OPCODE_UNTYPED_ATOMIC,
ibld.sample_mask_reg());
break;
case SHADER_OPCODE_TYPED_SURFACE_READ_LOGICAL:
lower_surface_logical_send(ibld, inst,
SHADER_OPCODE_TYPED_SURFACE_READ,
brw_imm_d(0xffff));
break;
case SHADER_OPCODE_TYPED_SURFACE_WRITE_LOGICAL:
lower_surface_logical_send(ibld, inst,
SHADER_OPCODE_TYPED_SURFACE_WRITE,
ibld.sample_mask_reg());
break;
case SHADER_OPCODE_TYPED_ATOMIC_LOGICAL:
lower_surface_logical_send(ibld, inst,
SHADER_OPCODE_TYPED_ATOMIC,
ibld.sample_mask_reg());
break;
case FS_OPCODE_VARYING_PULL_CONSTANT_LOAD_LOGICAL:
lower_varying_pull_constant_logical_send(ibld, inst);
break;
case SHADER_OPCODE_RCP:
case SHADER_OPCODE_RSQ:
case SHADER_OPCODE_SQRT:
case SHADER_OPCODE_EXP2:
case SHADER_OPCODE_LOG2:
case SHADER_OPCODE_SIN:
case SHADER_OPCODE_COS:
case SHADER_OPCODE_POW:
case SHADER_OPCODE_INT_QUOTIENT:
case SHADER_OPCODE_INT_REMAINDER:
/* The math opcodes are overloaded for the send-like and
* expression-like instructions which seems kind of icky. Gen6+ has
* a native (but rather quirky) MATH instruction so we don't need to
* do anything here. On Gen4-5 we'll have to lower the Gen6-like
* logical instructions (which we can easily recognize because they
* have mlen = 0) into send-like virtual instructions.
*/
if (devinfo->gen < 6 && inst->mlen == 0) {
lower_math_logical_send(ibld, inst);
break;
} else {
continue;
}
default:
continue;
}
progress = true;
}
if (progress)
invalidate_live_intervals();
return progress;
}
/**
* Get the closest allowed SIMD width for instruction \p inst accounting for
* some common regioning and execution control restrictions that apply to FPU
* instructions. These restrictions don't necessarily have any relevance to
* instructions not executed by the FPU pipeline like extended math, control
* flow or send message instructions.
*
* For virtual opcodes it's really up to the instruction -- In some cases
* (e.g. where a virtual instruction unrolls into a simple sequence of FPU
* instructions) it may simplify virtual instruction lowering if we can
* enforce FPU-like regioning restrictions already on the virtual instruction,
* in other cases (e.g. virtual send-like instructions) this may be
* excessively restrictive.
*/
static unsigned
get_fpu_lowered_simd_width(const struct gen_device_info *devinfo,
const fs_inst *inst)
{
/* Maximum execution size representable in the instruction controls. */
unsigned max_width = MIN2(32, inst->exec_size);
/* According to the PRMs:
* "A. In Direct Addressing mode, a source cannot span more than 2
* adjacent GRF registers.
* B. A destination cannot span more than 2 adjacent GRF registers."
*
* Look for the source or destination with the largest register region
* which is the one that is going to limit the overall execution size of
* the instruction due to this rule.
*/
unsigned reg_count = DIV_ROUND_UP(inst->size_written, REG_SIZE);
for (unsigned i = 0; i < inst->sources; i++)
reg_count = MAX2(reg_count, DIV_ROUND_UP(inst->size_read(i), REG_SIZE));
/* Calculate the maximum execution size of the instruction based on the
* factor by which it goes over the hardware limit of 2 GRFs.
*/
if (reg_count > 2)
max_width = MIN2(max_width, inst->exec_size / DIV_ROUND_UP(reg_count, 2));
/* According to the IVB PRMs:
* "When destination spans two registers, the source MUST span two
* registers. The exception to the above rule:
*
* - When source is scalar, the source registers are not incremented.
* - When source is packed integer Word and destination is packed
* integer DWord, the source register is not incremented but the
* source sub register is incremented."
*
* The hardware specs from Gen4 to Gen7.5 mention similar regioning
* restrictions. The code below intentionally doesn't check whether the
* destination type is integer because empirically the hardware doesn't
* seem to care what the actual type is as long as it's dword-aligned.
*/
if (devinfo->gen < 8) {
for (unsigned i = 0; i < inst->sources; i++) {
/* IVB implements DF scalars as <0;2,1> regions. */
const bool is_scalar_exception = is_uniform(inst->src[i]) &&
(devinfo->is_haswell || type_sz(inst->src[i].type) != 8);
const bool is_packed_word_exception =
type_sz(inst->dst.type) == 4 && inst->dst.stride == 1 &&
type_sz(inst->src[i].type) == 2 && inst->src[i].stride == 1;
if (inst->size_written > REG_SIZE &&
inst->size_read(i) != 0 && inst->size_read(i) <= REG_SIZE &&
!is_scalar_exception && !is_packed_word_exception) {
const unsigned reg_count = DIV_ROUND_UP(inst->size_written, REG_SIZE);
max_width = MIN2(max_width, inst->exec_size / reg_count);
}
}
}
/* From the IVB PRMs:
* "When an instruction is SIMD32, the low 16 bits of the execution mask
* are applied for both halves of the SIMD32 instruction. If different
* execution mask channels are required, split the instruction into two
* SIMD16 instructions."
*
* There is similar text in the HSW PRMs. Gen4-6 don't even implement
* 32-wide control flow support in hardware and will behave similarly.
*/
if (devinfo->gen < 8 && !inst->force_writemask_all)
max_width = MIN2(max_width, 16);
/* From the IVB PRMs (applies to HSW too):
* "Instructions with condition modifiers must not use SIMD32."
*
* From the BDW PRMs (applies to later hardware too):
* "Ternary instruction with condition modifiers must not use SIMD32."
*/
if (inst->conditional_mod && (devinfo->gen < 8 || inst->is_3src(devinfo)))
max_width = MIN2(max_width, 16);
/* From the IVB PRMs (applies to other devices that don't have the
* gen_device_info::supports_simd16_3src flag set):
* "In Align16 access mode, SIMD16 is not allowed for DW operations and
* SIMD8 is not allowed for DF operations."
*/
if (inst->is_3src(devinfo) && !devinfo->supports_simd16_3src)
max_width = MIN2(max_width, inst->exec_size / reg_count);
/* Pre-Gen8 EUs are hardwired to use the QtrCtrl+1 (where QtrCtrl is
* the 8-bit quarter of the execution mask signals specified in the
* instruction control fields) for the second compressed half of any
* single-precision instruction (for double-precision instructions
* it's hardwired to use NibCtrl+1, at least on HSW), which means that
* the EU will apply the wrong execution controls for the second
* sequential GRF write if the number of channels per GRF is not exactly
* eight in single-precision mode (or four in double-float mode).
*
* In this situation we calculate the maximum size of the split
* instructions so they only ever write to a single register.
*/
if (devinfo->gen < 8 && inst->size_written > REG_SIZE &&
!inst->force_writemask_all) {
const unsigned channels_per_grf = inst->exec_size /
DIV_ROUND_UP(inst->size_written, REG_SIZE);
const unsigned exec_type_size = get_exec_type_size(inst);
assert(exec_type_size);
/* The hardware shifts exactly 8 channels per compressed half of the
* instruction in single-precision mode and exactly 4 in double-precision.
*/
if (channels_per_grf != (exec_type_size == 8 ? 4 : 8))
max_width = MIN2(max_width, channels_per_grf);
/* Lower all non-force_writemask_all DF instructions to SIMD4 on IVB/BYT
* because HW applies the same channel enable signals to both halves of
* the compressed instruction which will be just wrong under
* non-uniform control flow.
*/
if (devinfo->gen == 7 && !devinfo->is_haswell &&
(exec_type_size == 8 || type_sz(inst->dst.type) == 8))
max_width = MIN2(max_width, 4);
}
/* Only power-of-two execution sizes are representable in the instruction
* control fields.
*/
return 1 << _mesa_logbase2(max_width);
}
/**
* Get the maximum allowed SIMD width for instruction \p inst accounting for
* various payload size restrictions that apply to sampler message
* instructions.
*
* This is only intended to provide a maximum theoretical bound for the
* execution size of the message based on the number of argument components
* alone, which in most cases will determine whether the SIMD8 or SIMD16
* variant of the message can be used, though some messages may have
* additional restrictions not accounted for here (e.g. pre-ILK hardware uses
* the message length to determine the exact SIMD width and argument count,
* which makes a number of sampler message combinations impossible to
* represent).
*/
static unsigned
get_sampler_lowered_simd_width(const struct gen_device_info *devinfo,
const fs_inst *inst)
{
/* Calculate the number of coordinate components that have to be present
* assuming that additional arguments follow the texel coordinates in the
* message payload. On IVB+ there is no need for padding, on ILK-SNB we
* need to pad to four or three components depending on the message,
* pre-ILK we need to pad to at most three components.
*/
const unsigned req_coord_components =
(devinfo->gen >= 7 ||
!inst->components_read(TEX_LOGICAL_SRC_COORDINATE)) ? 0 :
(devinfo->gen >= 5 && inst->opcode != SHADER_OPCODE_TXF_LOGICAL &&
inst->opcode != SHADER_OPCODE_TXF_CMS_LOGICAL) ? 4 :
3;
/* On Gen9+ the LOD argument is for free if we're able to use the LZ
* variant of the TXL or TXF message.
*/
const bool implicit_lod = devinfo->gen >= 9 &&
(inst->opcode == SHADER_OPCODE_TXL ||
inst->opcode == SHADER_OPCODE_TXF) &&
inst->src[TEX_LOGICAL_SRC_LOD].is_zero();
/* Calculate the total number of argument components that need to be passed
* to the sampler unit.
*/
const unsigned num_payload_components =
MAX2(inst->components_read(TEX_LOGICAL_SRC_COORDINATE),
req_coord_components) +
inst->components_read(TEX_LOGICAL_SRC_SHADOW_C) +
(implicit_lod ? 0 : inst->components_read(TEX_LOGICAL_SRC_LOD)) +
inst->components_read(TEX_LOGICAL_SRC_LOD2) +
inst->components_read(TEX_LOGICAL_SRC_SAMPLE_INDEX) +
(inst->opcode == SHADER_OPCODE_TG4_OFFSET_LOGICAL ?
inst->components_read(TEX_LOGICAL_SRC_TG4_OFFSET) : 0) +
inst->components_read(TEX_LOGICAL_SRC_MCS);
/* SIMD16 messages with more than five arguments exceed the maximum message
* size supported by the sampler, regardless of whether a header is
* provided or not.
*/
return MIN2(inst->exec_size,
num_payload_components > MAX_SAMPLER_MESSAGE_SIZE / 2 ? 8 : 16);
}
/**
* Get the closest native SIMD width supported by the hardware for instruction
* \p inst. The instruction will be left untouched by
* fs_visitor::lower_simd_width() if the returned value is equal to the
* original execution size.
*/
static unsigned
get_lowered_simd_width(const struct gen_device_info *devinfo,
const fs_inst *inst)
{
switch (inst->opcode) {
case BRW_OPCODE_MOV:
case BRW_OPCODE_SEL:
case BRW_OPCODE_NOT:
case BRW_OPCODE_AND:
case BRW_OPCODE_OR:
case BRW_OPCODE_XOR:
case BRW_OPCODE_SHR:
case BRW_OPCODE_SHL:
case BRW_OPCODE_ASR:
case BRW_OPCODE_CMPN:
case BRW_OPCODE_CSEL:
case BRW_OPCODE_F32TO16:
case BRW_OPCODE_F16TO32:
case BRW_OPCODE_BFREV:
case BRW_OPCODE_BFE:
case BRW_OPCODE_ADD:
case BRW_OPCODE_MUL:
case BRW_OPCODE_AVG:
case BRW_OPCODE_FRC:
case BRW_OPCODE_RNDU:
case BRW_OPCODE_RNDD:
case BRW_OPCODE_RNDE:
case BRW_OPCODE_RNDZ:
case BRW_OPCODE_LZD:
case BRW_OPCODE_FBH:
case BRW_OPCODE_FBL:
case BRW_OPCODE_CBIT:
case BRW_OPCODE_SAD2:
case BRW_OPCODE_MAD:
case BRW_OPCODE_LRP:
case FS_OPCODE_PACK:
return get_fpu_lowered_simd_width(devinfo, inst);
case BRW_OPCODE_CMP: {
/* The Ivybridge/BayTrail WaCMPInstFlagDepClearedEarly workaround says that
* when the destination is a GRF the dependency-clear bit on the flag
* register is cleared early.
*
* Suggested workarounds are to disable coissuing CMP instructions
* or to split CMP(16) instructions into two CMP(8) instructions.
*
* We choose to split into CMP(8) instructions since disabling
* coissuing would affect CMP instructions not otherwise affected by
* the errata.
*/
const unsigned max_width = (devinfo->gen == 7 && !devinfo->is_haswell &&
!inst->dst.is_null() ? 8 : ~0);
return MIN2(max_width, get_fpu_lowered_simd_width(devinfo, inst));
}
case BRW_OPCODE_BFI1:
case BRW_OPCODE_BFI2:
/* The Haswell WaForceSIMD8ForBFIInstruction workaround says that we
* should
* "Force BFI instructions to be executed always in SIMD8."
*/
return MIN2(devinfo->is_haswell ? 8 : ~0u,
get_fpu_lowered_simd_width(devinfo, inst));
case BRW_OPCODE_IF:
assert(inst->src[0].file == BAD_FILE || inst->exec_size <= 16);
return inst->exec_size;
case SHADER_OPCODE_RCP:
case SHADER_OPCODE_RSQ:
case SHADER_OPCODE_SQRT:
case SHADER_OPCODE_EXP2:
case SHADER_OPCODE_LOG2:
case SHADER_OPCODE_SIN:
case SHADER_OPCODE_COS:
/* Unary extended math instructions are limited to SIMD8 on Gen4 and
* Gen6.
*/
return (devinfo->gen >= 7 ? MIN2(16, inst->exec_size) :
devinfo->gen == 5 || devinfo->is_g4x ? MIN2(16, inst->exec_size) :
MIN2(8, inst->exec_size));
case SHADER_OPCODE_POW:
/* SIMD16 is only allowed on Gen7+. */
return (devinfo->gen >= 7 ? MIN2(16, inst->exec_size) :
MIN2(8, inst->exec_size));
case SHADER_OPCODE_INT_QUOTIENT:
case SHADER_OPCODE_INT_REMAINDER:
/* Integer division is limited to SIMD8 on all generations. */
return MIN2(8, inst->exec_size);
case FS_OPCODE_LINTERP:
case SHADER_OPCODE_GET_BUFFER_SIZE:
case FS_OPCODE_DDX_COARSE:
case FS_OPCODE_DDX_FINE:
case FS_OPCODE_DDY_COARSE:
case FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD:
case FS_OPCODE_VARYING_PULL_CONSTANT_LOAD_GEN7:
case FS_OPCODE_PACK_HALF_2x16_SPLIT:
case FS_OPCODE_UNPACK_HALF_2x16_SPLIT_X:
case FS_OPCODE_UNPACK_HALF_2x16_SPLIT_Y:
case FS_OPCODE_INTERPOLATE_AT_SAMPLE:
case FS_OPCODE_INTERPOLATE_AT_SHARED_OFFSET:
case FS_OPCODE_INTERPOLATE_AT_PER_SLOT_OFFSET:
return MIN2(16, inst->exec_size);
case FS_OPCODE_VARYING_PULL_CONSTANT_LOAD_LOGICAL:
/* Pre-ILK hardware doesn't have a SIMD8 variant of the texel fetch
* message used to implement varying pull constant loads, so expand it
* to SIMD16. An alternative with longer message payload length but
* shorter return payload would be to use the SIMD8 sampler message that
* takes (header, u, v, r) as parameters instead of (header, u).
*/
return (devinfo->gen == 4 ? 16 : MIN2(16, inst->exec_size));
case FS_OPCODE_DDY_FINE:
/* The implementation of this virtual opcode may require emitting
* compressed Align16 instructions, which are severely limited on some
* generations.
*
* From the Ivy Bridge PRM, volume 4 part 3, section 3.3.9 (Register
* Region Restrictions):
*
* "In Align16 access mode, SIMD16 is not allowed for DW operations
* and SIMD8 is not allowed for DF operations."
*
* In this context, "DW operations" means "operations acting on 32-bit
* values", so it includes operations on floats.
*
* Gen4 has a similar restriction. From the i965 PRM, section 11.5.3
* (Instruction Compression -> Rules and Restrictions):
*
* "A compressed instruction must be in Align1 access mode. Align16
* mode instructions cannot be compressed."
*
* Similar text exists in the g45 PRM.
*
* Empirically, compressed align16 instructions using odd register
* numbers don't appear to work on Sandybridge either.
*/
return (devinfo->gen == 4 || devinfo->gen == 6 ||
(devinfo->gen == 7 && !devinfo->is_haswell) ?
MIN2(8, inst->exec_size) : MIN2(16, inst->exec_size));
case SHADER_OPCODE_MULH:
/* MULH is lowered to the MUL/MACH sequence using the accumulator, which
* is 8-wide on Gen7+.
*/
return (devinfo->gen >= 7 ? 8 :
get_fpu_lowered_simd_width(devinfo, inst));
case FS_OPCODE_FB_WRITE_LOGICAL:
/* Gen6 doesn't support SIMD16 depth writes but we cannot handle them
* here.
*/
assert(devinfo->gen != 6 ||
inst->src[FB_WRITE_LOGICAL_SRC_SRC_DEPTH].file == BAD_FILE ||
inst->exec_size == 8);
/* Dual-source FB writes are unsupported in SIMD16 mode. */
return (inst->src[FB_WRITE_LOGICAL_SRC_COLOR1].file != BAD_FILE ?
8 : MIN2(16, inst->exec_size));
case FS_OPCODE_FB_READ_LOGICAL:
return MIN2(16, inst->exec_size);
case SHADER_OPCODE_TEX_LOGICAL:
case SHADER_OPCODE_TXF_CMS_LOGICAL:
case SHADER_OPCODE_TXF_UMS_LOGICAL:
case SHADER_OPCODE_TXF_MCS_LOGICAL:
case SHADER_OPCODE_LOD_LOGICAL:
case SHADER_OPCODE_TG4_LOGICAL:
case SHADER_OPCODE_SAMPLEINFO_LOGICAL:
case SHADER_OPCODE_TXF_CMS_W_LOGICAL:
case SHADER_OPCODE_TG4_OFFSET_LOGICAL:
return get_sampler_lowered_simd_width(devinfo, inst);
case SHADER_OPCODE_TXD_LOGICAL:
/* TXD is unsupported in SIMD16 mode. */
return 8;
case SHADER_OPCODE_TXL_LOGICAL:
case FS_OPCODE_TXB_LOGICAL:
/* Only one execution size is representable pre-ILK depending on whether
* the shadow reference argument is present.
*/
if (devinfo->gen == 4)
return inst->src[TEX_LOGICAL_SRC_SHADOW_C].file == BAD_FILE ? 16 : 8;
else
return get_sampler_lowered_simd_width(devinfo, inst);
case SHADER_OPCODE_TXF_LOGICAL:
case SHADER_OPCODE_TXS_LOGICAL:
/* Gen4 doesn't have SIMD8 variants for the RESINFO and LD-with-LOD
* messages. Use SIMD16 instead.
*/
if (devinfo->gen == 4)
return 16;
else
return get_sampler_lowered_simd_width(devinfo, inst);
case SHADER_OPCODE_TYPED_ATOMIC_LOGICAL:
case SHADER_OPCODE_TYPED_SURFACE_READ_LOGICAL:
case SHADER_OPCODE_TYPED_SURFACE_WRITE_LOGICAL:
return 8;
case SHADER_OPCODE_UNTYPED_ATOMIC_LOGICAL:
case SHADER_OPCODE_UNTYPED_SURFACE_READ_LOGICAL:
case SHADER_OPCODE_UNTYPED_SURFACE_WRITE_LOGICAL:
case SHADER_OPCODE_BYTE_SCATTERED_WRITE_LOGICAL:
case SHADER_OPCODE_BYTE_SCATTERED_READ_LOGICAL:
return MIN2(16, inst->exec_size);
case SHADER_OPCODE_URB_READ_SIMD8:
case SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT:
case SHADER_OPCODE_URB_WRITE_SIMD8:
case SHADER_OPCODE_URB_WRITE_SIMD8_PER_SLOT:
case SHADER_OPCODE_URB_WRITE_SIMD8_MASKED:
case SHADER_OPCODE_URB_WRITE_SIMD8_MASKED_PER_SLOT:
return MIN2(8, inst->exec_size);
case SHADER_OPCODE_MOV_INDIRECT: {
/* From IVB and HSW PRMs:
*
* "2.When the destination requires two registers and the sources are
* indirect, the sources must use 1x1 regioning mode.
*
* In case of DF instructions in HSW/IVB, the exec_size is limited by
* the EU decompression logic not handling VxH indirect addressing
* correctly.
*/
const unsigned max_size = (devinfo->gen >= 8 ? 2 : 1) * REG_SIZE;
/* Prior to Broadwell, we only have 8 address subregisters. */
return MIN3(devinfo->gen >= 8 ? 16 : 8,
max_size / (inst->dst.stride * type_sz(inst->dst.type)),
inst->exec_size);
}
case SHADER_OPCODE_LOAD_PAYLOAD: {
const unsigned reg_count =
DIV_ROUND_UP(inst->dst.component_size(inst->exec_size), REG_SIZE);
if (reg_count > 2) {
/* Only LOAD_PAYLOAD instructions with per-channel destination region
* can be easily lowered (which excludes headers and heterogeneous
* types).
*/
assert(!inst->header_size);
for (unsigned i = 0; i < inst->sources; i++)
assert(type_sz(inst->dst.type) == type_sz(inst->src[i].type) ||
inst->src[i].file == BAD_FILE);
return inst->exec_size / DIV_ROUND_UP(reg_count, 2);
} else {
return inst->exec_size;
}
}
default:
return inst->exec_size;
}
}
/**
* Return true if splitting out the group of channels of instruction \p inst
* given by lbld.group() requires allocating a temporary for the i-th source
* of the lowered instruction.
*/
static inline bool
needs_src_copy(const fs_builder &lbld, const fs_inst *inst, unsigned i)
{
return !(is_periodic(inst->src[i], lbld.dispatch_width()) ||
(inst->components_read(i) == 1 &&
lbld.dispatch_width() <= inst->exec_size)) ||
(inst->flags_written() &
flag_mask(inst->src[i], type_sz(inst->src[i].type)));
}
/**
* Extract the data that would be consumed by the channel group given by
* lbld.group() from the i-th source region of instruction \p inst and return
* it as result in packed form.
*/
static fs_reg
emit_unzip(const fs_builder &lbld, fs_inst *inst, unsigned i)
{
/* Specified channel group from the source region. */
const fs_reg src = horiz_offset(inst->src[i], lbld.group());
if (needs_src_copy(lbld, inst, i)) {
/* Builder of the right width to perform the copy avoiding uninitialized
* data if the lowered execution size is greater than the original
* execution size of the instruction.
*/
const fs_builder cbld = lbld.group(MIN2(lbld.dispatch_width(),
inst->exec_size), 0);
const fs_reg tmp = lbld.vgrf(inst->src[i].type, inst->components_read(i));
for (unsigned k = 0; k < inst->components_read(i); ++k)
cbld.MOV(offset(tmp, lbld, k), offset(src, inst->exec_size, k));
return tmp;
} else if (is_periodic(inst->src[i], lbld.dispatch_width())) {
/* The source is invariant for all dispatch_width-wide groups of the
* original region.
*/
return inst->src[i];
} else {
/* We can just point the lowered instruction at the right channel group
* from the original region.
*/
return src;
}
}
/**
* Return true if splitting out the group of channels of instruction \p inst
* given by lbld.group() requires allocating a temporary for the destination
* of the lowered instruction and copying the data back to the original
* destination region.
*/
static inline bool
needs_dst_copy(const fs_builder &lbld, const fs_inst *inst)
{
/* If the instruction writes more than one component we'll have to shuffle
* the results of multiple lowered instructions in order to make sure that
* they end up arranged correctly in the original destination region.
*/
if (inst->size_written > inst->dst.component_size(inst->exec_size))
return true;
/* If the lowered execution size is larger than the original the result of
* the instruction won't fit in the original destination, so we'll have to
* allocate a temporary in any case.
*/
if (lbld.dispatch_width() > inst->exec_size)
return true;
for (unsigned i = 0; i < inst->sources; i++) {
/* If we already made a copy of the source for other reasons there won't
* be any overlap with the destination.
*/
if (needs_src_copy(lbld, inst, i))
continue;
/* In order to keep the logic simple we emit a copy whenever the
* destination region doesn't exactly match an overlapping source, which
* may point at the source and destination not being aligned group by
* group which could cause one of the lowered instructions to overwrite
* the data read from the same source by other lowered instructions.
*/
if (regions_overlap(inst->dst, inst->size_written,
inst->src[i], inst->size_read(i)) &&
!inst->dst.equals(inst->src[i]))
return true;
}
return false;
}
/**
* Insert data from a packed temporary into the channel group given by
* lbld.group() of the destination region of instruction \p inst and return
* the temporary as result. Any copy instructions that are required for
* unzipping the previous value (in the case of partial writes) will be
* inserted using \p lbld_before and any copy instructions required for
* zipping up the destination of \p inst will be inserted using \p lbld_after.
*/
static fs_reg
emit_zip(const fs_builder &lbld_before, const fs_builder &lbld_after,
fs_inst *inst)
{
assert(lbld_before.dispatch_width() == lbld_after.dispatch_width());
assert(lbld_before.group() == lbld_after.group());
/* Specified channel group from the destination region. */
const fs_reg dst = horiz_offset(inst->dst, lbld_after.group());
const unsigned dst_size = inst->size_written /
inst->dst.component_size(inst->exec_size);
if (needs_dst_copy(lbld_after, inst)) {
const fs_reg tmp = lbld_after.vgrf(inst->dst.type, dst_size);
if (inst->predicate) {
/* Handle predication by copying the original contents of
* the destination into the temporary before emitting the
* lowered instruction.
*/
const fs_builder gbld_before =
lbld_before.group(MIN2(lbld_before.dispatch_width(),
inst->exec_size), 0);
for (unsigned k = 0; k < dst_size; ++k) {
gbld_before.MOV(offset(tmp, lbld_before, k),
offset(dst, inst->exec_size, k));
}
}
const fs_builder gbld_after =
lbld_after.group(MIN2(lbld_after.dispatch_width(),
inst->exec_size), 0);
for (unsigned k = 0; k < dst_size; ++k) {
/* Use a builder of the right width to perform the copy avoiding
* uninitialized data if the lowered execution size is greater than
* the original execution size of the instruction.
*/
gbld_after.MOV(offset(dst, inst->exec_size, k),
offset(tmp, lbld_after, k));
}
return tmp;
} else {
/* No need to allocate a temporary for the lowered instruction, just
* take the right group of channels from the original region.
*/
return dst;
}
}
bool
fs_visitor::lower_simd_width()
{
bool progress = false;
foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
const unsigned lower_width = get_lowered_simd_width(devinfo, inst);
if (lower_width != inst->exec_size) {
/* Builder matching the original instruction. We may also need to
* emit an instruction of width larger than the original, set the
* execution size of the builder to the highest of both for now so
* we're sure that both cases can be handled.
*/
const unsigned max_width = MAX2(inst->exec_size, lower_width);
const fs_builder ibld = bld.at(block, inst)
.exec_all(inst->force_writemask_all)
.group(max_width, inst->group / max_width);
/* Split the copies in chunks of the execution width of either the
* original or the lowered instruction, whichever is lower.
*/
const unsigned n = DIV_ROUND_UP(inst->exec_size, lower_width);
const unsigned dst_size = inst->size_written /
inst->dst.component_size(inst->exec_size);
assert(!inst->writes_accumulator && !inst->mlen);
/* Inserting the zip, unzip, and duplicated instructions in all of
* the right spots is somewhat tricky. All of the unzip and any
* instructions from the zip which unzip the destination prior to
* writing need to happen before all of the per-group instructions
* and the zip instructions need to happen after. In order to sort
* this all out, we insert the unzip instructions before \p inst,
* insert the per-group instructions after \p inst (i.e. before
* inst->next), and insert the zip instructions before the
* instruction after \p inst. Since we are inserting instructions
* after \p inst, inst->next is a moving target and we need to save
* it off here so that we insert the zip instructions in the right
* place.
*/
exec_node *const after_inst = inst->next;
for (unsigned i = 0; i < n; i++) {
/* Emit a copy of the original instruction with the lowered width.
* If the EOT flag was set throw it away except for the last
* instruction to avoid killing the thread prematurely.
*/
fs_inst split_inst = *inst;
split_inst.exec_size = lower_width;
split_inst.eot = inst->eot && i == 0;
/* Select the correct channel enables for the i-th group, then
* transform the sources and destination and emit the lowered
* instruction.
*/
const fs_builder lbld = ibld.group(lower_width, i);
for (unsigned j = 0; j < inst->sources; j++)
split_inst.src[j] = emit_unzip(lbld.at(block, inst), inst, j);
split_inst.dst = emit_zip(lbld.at(block, inst),
lbld.at(block, after_inst), inst);
split_inst.size_written =
split_inst.dst.component_size(lower_width) * dst_size;
lbld.at(block, inst->next).emit(split_inst);
}
inst->remove(block);
progress = true;
}
}
if (progress)
invalidate_live_intervals();
return progress;
}
void
fs_visitor::dump_instructions()
{
dump_instructions(NULL);
}
void
fs_visitor::dump_instructions(const char *name)
{
FILE *file = stderr;
if (name && geteuid() != 0) {
file = fopen(name, "w");
if (!file)
file = stderr;
}
if (cfg) {
calculate_register_pressure();
int ip = 0, max_pressure = 0;
foreach_block_and_inst(block, backend_instruction, inst, cfg) {
max_pressure = MAX2(max_pressure, regs_live_at_ip[ip]);
fprintf(file, "{%3d} %4d: ", regs_live_at_ip[ip], ip);
dump_instruction(inst, file);
ip++;
}
fprintf(file, "Maximum %3d registers live at once.\n", max_pressure);
} else {
int ip = 0;
foreach_in_list(backend_instruction, inst, &instructions) {
fprintf(file, "%4d: ", ip++);
dump_instruction(inst, file);
}
}
if (file != stderr) {
fclose(file);
}
}
void
fs_visitor::dump_instruction(backend_instruction *be_inst)
{
dump_instruction(be_inst, stderr);
}
void
fs_visitor::dump_instruction(backend_instruction *be_inst, FILE *file)
{
fs_inst *inst = (fs_inst *)be_inst;
if (inst->predicate) {
fprintf(file, "(%cf0.%d) ",
inst->predicate_inverse ? '-' : '+',
inst->flag_subreg);
}
fprintf(file, "%s", brw_instruction_name(devinfo, inst->opcode));
if (inst->saturate)
fprintf(file, ".sat");
if (inst->conditional_mod) {
fprintf(file, "%s", conditional_modifier[inst->conditional_mod]);
if (!inst->predicate &&
(devinfo->gen < 5 || (inst->opcode != BRW_OPCODE_SEL &&
inst->opcode != BRW_OPCODE_IF &&
inst->opcode != BRW_OPCODE_WHILE))) {
fprintf(file, ".f0.%d", inst->flag_subreg);
}
}
fprintf(file, "(%d) ", inst->exec_size);
if (inst->mlen) {
fprintf(file, "(mlen: %d) ", inst->mlen);
}
if (inst->eot) {
fprintf(file, "(EOT) ");
}
switch (inst->dst.file) {
case VGRF:
fprintf(file, "vgrf%d", inst->dst.nr);
break;
case FIXED_GRF:
fprintf(file, "g%d", inst->dst.nr);
break;
case MRF:
fprintf(file, "m%d", inst->dst.nr);
break;
case BAD_FILE:
fprintf(file, "(null)");
break;
case UNIFORM:
fprintf(file, "***u%d***", inst->dst.nr);
break;
case ATTR:
fprintf(file, "***attr%d***", inst->dst.nr);
break;
case ARF:
switch (inst->dst.nr) {
case BRW_ARF_NULL:
fprintf(file, "null");
break;
case BRW_ARF_ADDRESS:
fprintf(file, "a0.%d", inst->dst.subnr);
break;
case BRW_ARF_ACCUMULATOR:
fprintf(file, "acc%d", inst->dst.subnr);
break;
case BRW_ARF_FLAG:
fprintf(file, "f%d.%d", inst->dst.nr & 0xf, inst->dst.subnr);
break;
default:
fprintf(file, "arf%d.%d", inst->dst.nr & 0xf, inst->dst.subnr);
break;
}
break;
case IMM:
unreachable("not reached");
}
if (inst->dst.offset ||
(inst->dst.file == VGRF &&
alloc.sizes[inst->dst.nr] * REG_SIZE != inst->size_written)) {
const unsigned reg_size = (inst->dst.file == UNIFORM ? 4 : REG_SIZE);
fprintf(file, "+%d.%d", inst->dst.offset / reg_size,
inst->dst.offset % reg_size);
}
if (inst->dst.stride != 1)
fprintf(file, "<%u>", inst->dst.stride);
fprintf(file, ":%s, ", brw_reg_type_to_letters(inst->dst.type));
for (int i = 0; i < inst->sources; i++) {
if (inst->src[i].negate)
fprintf(file, "-");
if (inst->src[i].abs)
fprintf(file, "|");
switch (inst->src[i].file) {
case VGRF:
fprintf(file, "vgrf%d", inst->src[i].nr);
break;
case FIXED_GRF:
fprintf(file, "g%d", inst->src[i].nr);
break;
case MRF:
fprintf(file, "***m%d***", inst->src[i].nr);
break;
case ATTR:
fprintf(file, "attr%d", inst->src[i].nr);
break;
case UNIFORM:
fprintf(file, "u%d", inst->src[i].nr);
break;
case BAD_FILE:
fprintf(file, "(null)");
break;
case IMM:
switch (inst->src[i].type) {
case BRW_REGISTER_TYPE_F:
fprintf(file, "%-gf", inst->src[i].f);
break;
case BRW_REGISTER_TYPE_DF:
fprintf(file, "%fdf", inst->src[i].df);
break;
case BRW_REGISTER_TYPE_W:
case BRW_REGISTER_TYPE_D:
fprintf(file, "%dd", inst->src[i].d);
break;
case BRW_REGISTER_TYPE_UW:
case BRW_REGISTER_TYPE_UD:
fprintf(file, "%uu", inst->src[i].ud);
break;
case BRW_REGISTER_TYPE_VF:
fprintf(file, "[%-gF, %-gF, %-gF, %-gF]",
brw_vf_to_float((inst->src[i].ud >> 0) & 0xff),
brw_vf_to_float((inst->src[i].ud >> 8) & 0xff),
brw_vf_to_float((inst->src[i].ud >> 16) & 0xff),
brw_vf_to_float((inst->src[i].ud >> 24) & 0xff));
break;
default:
fprintf(file, "???");
break;
}
break;
case ARF:
switch (inst->src[i].nr) {
case BRW_ARF_NULL:
fprintf(file, "null");
break;
case BRW_ARF_ADDRESS:
fprintf(file, "a0.%d", inst->src[i].subnr);
break;
case BRW_ARF_ACCUMULATOR:
fprintf(file, "acc%d", inst->src[i].subnr);
break;
case BRW_ARF_FLAG:
fprintf(file, "f%d.%d", inst->src[i].nr & 0xf, inst->src[i].subnr);
break;
default:
fprintf(file, "arf%d.%d", inst->src[i].nr & 0xf, inst->src[i].subnr);
break;
}
break;
}
if (inst->src[i].offset ||
(inst->src[i].file == VGRF &&
alloc.sizes[inst->src[i].nr] * REG_SIZE != inst->size_read(i))) {
const unsigned reg_size = (inst->src[i].file == UNIFORM ? 4 : REG_SIZE);
fprintf(file, "+%d.%d", inst->src[i].offset / reg_size,
inst->src[i].offset % reg_size);
}
if (inst->src[i].abs)
fprintf(file, "|");
if (inst->src[i].file != IMM) {
unsigned stride;
if (inst->src[i].file == ARF || inst->src[i].file == FIXED_GRF) {
unsigned hstride = inst->src[i].hstride;
stride = (hstride == 0 ? 0 : (1 << (hstride - 1)));
} else {
stride = inst->src[i].stride;
}
if (stride != 1)
fprintf(file, "<%u>", stride);
fprintf(file, ":%s", brw_reg_type_to_letters(inst->src[i].type));
}
if (i < inst->sources - 1 && inst->src[i + 1].file != BAD_FILE)
fprintf(file, ", ");
}
fprintf(file, " ");
if (inst->force_writemask_all)
fprintf(file, "NoMask ");
if (inst->exec_size != dispatch_width)
fprintf(file, "group%d ", inst->group);
fprintf(file, "\n");
}
/**
* Possibly returns an instruction that set up @param reg.
*
* Sometimes we want to take the result of some expression/variable
* dereference tree and rewrite the instruction generating the result
* of the tree. When processing the tree, we know that the
* instructions generated are all writing temporaries that are dead
* outside of this tree. So, if we have some instructions that write
* a temporary, we're free to point that temp write somewhere else.
*
* Note that this doesn't guarantee that the instruction generated
* only reg -- it might be the size=4 destination of a texture instruction.
*/
fs_inst *
fs_visitor::get_instruction_generating_reg(fs_inst *start,
fs_inst *end,
const fs_reg ®)
{
if (end == start ||
end->is_partial_write() ||
!reg.equals(end->dst)) {
return NULL;
} else {
return end;
}
}
void
fs_visitor::setup_fs_payload_gen6()
{
assert(stage == MESA_SHADER_FRAGMENT);
struct brw_wm_prog_data *prog_data = brw_wm_prog_data(this->prog_data);
assert(devinfo->gen >= 6);
/* R0-1: masks, pixel X/Y coordinates. */
payload.num_regs = 2;
/* R2: only for 32-pixel dispatch.*/
/* R3-26: barycentric interpolation coordinates. These appear in the
* same order that they appear in the brw_barycentric_mode
* enum. Each set of coordinates occupies 2 registers if dispatch width
* == 8 and 4 registers if dispatch width == 16. Coordinates only
* appear if they were enabled using the "Barycentric Interpolation
* Mode" bits in WM_STATE.
*/
for (int i = 0; i < BRW_BARYCENTRIC_MODE_COUNT; ++i) {
if (prog_data->barycentric_interp_modes & (1 << i)) {
payload.barycentric_coord_reg[i] = payload.num_regs;
payload.num_regs += 2;
if (dispatch_width == 16) {
payload.num_regs += 2;
}
}
}
/* R27: interpolated depth if uses source depth */
prog_data->uses_src_depth =
(nir->info.inputs_read & (1 << VARYING_SLOT_POS)) != 0;
if (prog_data->uses_src_depth) {
payload.source_depth_reg = payload.num_regs;
payload.num_regs++;
if (dispatch_width == 16) {
/* R28: interpolated depth if not SIMD8. */
payload.num_regs++;
}
}
/* R29: interpolated W set if GEN6_WM_USES_SOURCE_W. */
prog_data->uses_src_w =
(nir->info.inputs_read & (1 << VARYING_SLOT_POS)) != 0;
if (prog_data->uses_src_w) {
payload.source_w_reg = payload.num_regs;
payload.num_regs++;
if (dispatch_width == 16) {
/* R30: interpolated W if not SIMD8. */
payload.num_regs++;
}
}
/* R31: MSAA position offsets. */
if (prog_data->persample_dispatch &&
(nir->info.system_values_read & SYSTEM_BIT_SAMPLE_POS)) {
/* From the Ivy Bridge PRM documentation for 3DSTATE_PS:
*
* "MSDISPMODE_PERSAMPLE is required in order to select
* POSOFFSET_SAMPLE"
*
* So we can only really get sample positions if we are doing real
* per-sample dispatch. If we need gl_SamplePosition and we don't have
* persample dispatch, we hard-code it to 0.5.
*/
prog_data->uses_pos_offset = true;
payload.sample_pos_reg = payload.num_regs;
payload.num_regs++;
}
/* R32: MSAA input coverage mask */
prog_data->uses_sample_mask =
(nir->info.system_values_read & SYSTEM_BIT_SAMPLE_MASK_IN) != 0;
if (prog_data->uses_sample_mask) {
assert(devinfo->gen >= 7);
payload.sample_mask_in_reg = payload.num_regs;
payload.num_regs++;
if (dispatch_width == 16) {
/* R33: input coverage mask if not SIMD8. */
payload.num_regs++;
}
}
/* R34-: bary for 32-pixel. */
/* R58-59: interp W for 32-pixel. */
if (nir->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
source_depth_to_render_target = true;
}
}
void
fs_visitor::setup_vs_payload()
{
/* R0: thread header, R1: urb handles */
payload.num_regs = 2;
}
void
fs_visitor::setup_gs_payload()
{
assert(stage == MESA_SHADER_GEOMETRY);
struct brw_gs_prog_data *gs_prog_data = brw_gs_prog_data(prog_data);
struct brw_vue_prog_data *vue_prog_data = brw_vue_prog_data(prog_data);
/* R0: thread header, R1: output URB handles */
payload.num_regs = 2;
if (gs_prog_data->include_primitive_id) {
/* R2: Primitive ID 0..7 */
payload.num_regs++;
}
/* Always enable VUE handles so we can safely use pull model if needed.
*
* The push model for a GS uses a ton of register space even for trivial
* scenarios with just a few inputs, so just make things easier and a bit
* safer by always having pull model available.
*/
gs_prog_data->base.include_vue_handles = true;
/* R3..RN: ICP Handles for each incoming vertex (when using pull model) */
payload.num_regs += nir->info.gs.vertices_in;
/* Use a maximum of 24 registers for push-model inputs. */
const unsigned max_push_components = 24;
/* If pushing our inputs would take too many registers, reduce the URB read
* length (which is in HWords, or 8 registers), and resort to pulling.
*
* Note that the GS reads <URB Read Length> HWords for every vertex - so we
* have to multiply by VerticesIn to obtain the total storage requirement.
*/
if (8 * vue_prog_data->urb_read_length * nir->info.gs.vertices_in >
max_push_components) {
vue_prog_data->urb_read_length =
ROUND_DOWN_TO(max_push_components / nir->info.gs.vertices_in, 8) / 8;
}
}
void
fs_visitor::setup_cs_payload()
{
assert(devinfo->gen >= 7);
payload.num_regs = 1;
}
void
fs_visitor::calculate_register_pressure()
{
invalidate_live_intervals();
calculate_live_intervals();
unsigned num_instructions = 0;
foreach_block(block, cfg)
num_instructions += block->instructions.length();
regs_live_at_ip = rzalloc_array(mem_ctx, int, num_instructions);
for (unsigned reg = 0; reg < alloc.count; reg++) {
for (int ip = virtual_grf_start[reg]; ip <= virtual_grf_end[reg]; ip++)
regs_live_at_ip[ip] += alloc.sizes[reg];
}
}
/**
* Look for repeated FS_OPCODE_MOV_DISPATCH_TO_FLAGS and drop the later ones.
*
* The needs_unlit_centroid_workaround ends up producing one of these per
* channel of centroid input, so it's good to clean them up.
*
* An assumption here is that nothing ever modifies the dispatched pixels
* value that FS_OPCODE_MOV_DISPATCH_TO_FLAGS reads from, but the hardware
* dictates that anyway.
*/
bool
fs_visitor::opt_drop_redundant_mov_to_flags()
{
bool flag_mov_found[2] = {false};
bool progress = false;
/* Instructions removed by this pass can only be added if this were true */
if (!devinfo->needs_unlit_centroid_workaround)
return false;
foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
if (inst->is_control_flow()) {
memset(flag_mov_found, 0, sizeof(flag_mov_found));
} else if (inst->opcode == FS_OPCODE_MOV_DISPATCH_TO_FLAGS) {
if (!flag_mov_found[inst->flag_subreg]) {
flag_mov_found[inst->flag_subreg] = true;
} else {
inst->remove(block);
progress = true;
}
} else if (inst->flags_written()) {
flag_mov_found[inst->flag_subreg] = false;
}
}
return progress;
}
void
fs_visitor::optimize()
{
/* Start by validating the shader we currently have. */
validate();
/* bld is the common builder object pointing at the end of the program we
* used to translate it into i965 IR. For the optimization and lowering
* passes coming next, any code added after the end of the program without
* having explicitly called fs_builder::at() clearly points at a mistake.
* Ideally optimization passes wouldn't be part of the visitor so they
* wouldn't have access to bld at all, but they do, so just in case some
* pass forgets to ask for a location explicitly set it to NULL here to
* make it trip. The dispatch width is initialized to a bogus value to
* make sure that optimizations set the execution controls explicitly to
* match the code they are manipulating instead of relying on the defaults.
*/
bld = fs_builder(this, 64);
assign_constant_locations();
lower_constant_loads();
validate();
split_virtual_grfs();
validate();
#define OPT(pass, args...) ({ \
pass_num++; \
bool this_progress = pass(args); \
\
if (unlikely(INTEL_DEBUG & DEBUG_OPTIMIZER) && this_progress) { \
char filename[64]; \
snprintf(filename, 64, "%s%d-%s-%02d-%02d-" #pass, \
stage_abbrev, dispatch_width, nir->info.name, iteration, pass_num); \
\
backend_shader::dump_instructions(filename); \
} \
\
validate(); \
\
progress = progress || this_progress; \
this_progress; \
})
if (unlikely(INTEL_DEBUG & DEBUG_OPTIMIZER)) {
char filename[64];
snprintf(filename, 64, "%s%d-%s-00-00-start",
stage_abbrev, dispatch_width, nir->info.name);
backend_shader::dump_instructions(filename);
}
bool progress = false;
int iteration = 0;
int pass_num = 0;
OPT(opt_drop_redundant_mov_to_flags);
OPT(remove_extra_rounding_modes);
do {
progress = false;
pass_num = 0;
iteration++;
OPT(remove_duplicate_mrf_writes);
OPT(opt_algebraic);
OPT(opt_cse);
OPT(opt_copy_propagation);
OPT(opt_predicated_break, this);
OPT(opt_cmod_propagation);
OPT(dead_code_eliminate);
OPT(opt_peephole_sel);
OPT(dead_control_flow_eliminate, this);
OPT(opt_register_renaming);
OPT(opt_saturate_propagation);
OPT(register_coalesce);
OPT(compute_to_mrf);
OPT(eliminate_find_live_channel);
OPT(compact_virtual_grfs);
} while (progress);
progress = false;
pass_num = 0;
if (OPT(lower_pack)) {
OPT(register_coalesce);
OPT(dead_code_eliminate);
}
OPT(lower_simd_width);
/* After SIMD lowering just in case we had to unroll the EOT send. */
OPT(opt_sampler_eot);
OPT(lower_logical_sends);
if (progress) {
OPT(opt_copy_propagation);
/* Only run after logical send lowering because it's easier to implement
* in terms of physical sends.
*/
if (OPT(opt_zero_samples))
OPT(opt_copy_propagation);
/* Run after logical send lowering to give it a chance to CSE the
* LOAD_PAYLOAD instructions created to construct the payloads of
* e.g. texturing messages in cases where it wasn't possible to CSE the
* whole logical instruction.
*/
OPT(opt_cse);
OPT(register_coalesce);
OPT(compute_to_mrf);
OPT(dead_code_eliminate);
OPT(remove_duplicate_mrf_writes);
OPT(opt_peephole_sel);
}
OPT(opt_redundant_discard_jumps);
if (OPT(lower_load_payload)) {
split_virtual_grfs();
OPT(register_coalesce);
OPT(compute_to_mrf);
OPT(dead_code_eliminate);
}
OPT(opt_combine_constants);
OPT(lower_integer_multiplication);
if (devinfo->gen <= 5 && OPT(lower_minmax)) {
OPT(opt_cmod_propagation);
OPT(opt_cse);
OPT(opt_copy_propagation);
OPT(dead_code_eliminate);
}
if (OPT(lower_conversions)) {
OPT(opt_copy_propagation);
OPT(dead_code_eliminate);
OPT(lower_simd_width);
}
lower_uniform_pull_constant_loads();
validate();
}
/**
* Three source instruction must have a GRF/MRF destination register.
* ARF NULL is not allowed. Fix that up by allocating a temporary GRF.
*/
void
fs_visitor::fixup_3src_null_dest()
{
bool progress = false;
foreach_block_and_inst_safe (block, fs_inst, inst, cfg) {
if (inst->is_3src(devinfo) && inst->dst.is_null()) {
inst->dst = fs_reg(VGRF, alloc.allocate(dispatch_width / 8),
inst->dst.type);
progress = true;
}
}
if (progress)
invalidate_live_intervals();
}
void
fs_visitor::allocate_registers(unsigned min_dispatch_width, bool allow_spilling)
{
bool allocated_without_spills;
static const enum instruction_scheduler_mode pre_modes[] = {
SCHEDULE_PRE,
SCHEDULE_PRE_NON_LIFO,
SCHEDULE_PRE_LIFO,
};
bool spill_all = allow_spilling && (INTEL_DEBUG & DEBUG_SPILL_FS);
/* Try each scheduling heuristic to see if it can successfully register
* allocate without spilling. They should be ordered by decreasing
* performance but increasing likelihood of allocating.
*/
for (unsigned i = 0; i < ARRAY_SIZE(pre_modes); i++) {
schedule_instructions(pre_modes[i]);
if (0) {
assign_regs_trivial();
allocated_without_spills = true;
} else {
allocated_without_spills = assign_regs(false, spill_all);
}
if (allocated_without_spills)
break;
}
if (!allocated_without_spills) {
if (!allow_spilling)
fail("Failure to register allocate and spilling is not allowed.");
/* We assume that any spilling is worse than just dropping back to
* SIMD8. There's probably actually some intermediate point where
* SIMD16 with a couple of spills is still better.
*/
if (dispatch_width > min_dispatch_width) {
fail("Failure to register allocate. Reduce number of "
"live scalar values to avoid this.");
} else {
compiler->shader_perf_log(log_data,
"%s shader triggered register spilling. "
"Try reducing the number of live scalar "
"values to improve performance.\n",
stage_name);
}
/* Since we're out of heuristics, just go spill registers until we
* get an allocation.
*/
while (!assign_regs(true, spill_all)) {
if (failed)
break;
}
}
/* This must come after all optimization and register allocation, since
* it inserts dead code that happens to have side effects, and it does
* so based on the actual physical registers in use.
*/
insert_gen4_send_dependency_workarounds();
if (failed)
return;
opt_bank_conflicts();
schedule_instructions(SCHEDULE_POST);
if (last_scratch > 0) {
MAYBE_UNUSED unsigned max_scratch_size = 2 * 1024 * 1024;
prog_data->total_scratch = brw_get_scratch_size(last_scratch);
if (stage == MESA_SHADER_COMPUTE) {
if (devinfo->is_haswell) {
/* According to the MEDIA_VFE_STATE's "Per Thread Scratch Space"
* field documentation, Haswell supports a minimum of 2kB of
* scratch space for compute shaders, unlike every other stage
* and platform.
*/
prog_data->total_scratch = MAX2(prog_data->total_scratch, 2048);
} else if (devinfo->gen <= 7) {
/* According to the MEDIA_VFE_STATE's "Per Thread Scratch Space"
* field documentation, platforms prior to Haswell measure scratch
* size linearly with a range of [1kB, 12kB] and 1kB granularity.
*/
prog_data->total_scratch = ALIGN(last_scratch, 1024);
max_scratch_size = 12 * 1024;
}
}
/* We currently only support up to 2MB of scratch space. If we
* need to support more eventually, the documentation suggests
* that we could allocate a larger buffer, and partition it out
* ourselves. We'd just have to undo the hardware's address
* calculation by subtracting (FFTID * Per Thread Scratch Space)
* and then add FFTID * (Larger Per Thread Scratch Space).
*
* See 3D-Media-GPGPU Engine > Media GPGPU Pipeline >
* Thread Group Tracking > Local Memory/Scratch Space.
*/
assert(prog_data->total_scratch < max_scratch_size);
}
}
bool
fs_visitor::run_vs()
{
assert(stage == MESA_SHADER_VERTEX);
setup_vs_payload();
if (shader_time_index >= 0)
emit_shader_time_begin();
emit_nir_code();
if (failed)
return false;
compute_clip_distance();
emit_urb_writes();
if (shader_time_index >= 0)
emit_shader_time_end();
calculate_cfg();
optimize();
assign_curb_setup();
assign_vs_urb_setup();
fixup_3src_null_dest();
allocate_registers(8, true);
return !failed;
}
bool
fs_visitor::run_tcs_single_patch()
{
assert(stage == MESA_SHADER_TESS_CTRL);
struct brw_tcs_prog_data *tcs_prog_data = brw_tcs_prog_data(prog_data);
/* r1-r4 contain the ICP handles. */
payload.num_regs = 5;
if (shader_time_index >= 0)
emit_shader_time_begin();
/* Initialize gl_InvocationID */
fs_reg channels_uw = bld.vgrf(BRW_REGISTER_TYPE_UW);
fs_reg channels_ud = bld.vgrf(BRW_REGISTER_TYPE_UD);
bld.MOV(channels_uw, fs_reg(brw_imm_uv(0x76543210)));
bld.MOV(channels_ud, channels_uw);
if (tcs_prog_data->instances == 1) {
invocation_id = channels_ud;
} else {
invocation_id = bld.vgrf(BRW_REGISTER_TYPE_UD);
/* Get instance number from g0.2 bits 23:17, and multiply it by 8. */
fs_reg t = bld.vgrf(BRW_REGISTER_TYPE_UD);
fs_reg instance_times_8 = bld.vgrf(BRW_REGISTER_TYPE_UD);
bld.AND(t, fs_reg(retype(brw_vec1_grf(0, 2), BRW_REGISTER_TYPE_UD)),
brw_imm_ud(INTEL_MASK(23, 17)));
bld.SHR(instance_times_8, t, brw_imm_ud(17 - 3));
bld.ADD(invocation_id, instance_times_8, channels_ud);
}
/* Fix the disptach mask */
if (nir->info.tess.tcs_vertices_out % 8) {
bld.CMP(bld.null_reg_ud(), invocation_id,
brw_imm_ud(nir->info.tess.tcs_vertices_out), BRW_CONDITIONAL_L);
bld.IF(BRW_PREDICATE_NORMAL);
}
emit_nir_code();
if (nir->info.tess.tcs_vertices_out % 8) {
bld.emit(BRW_OPCODE_ENDIF);
}
/* Emit EOT write; set TR DS Cache bit */
fs_reg srcs[3] = {
fs_reg(retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_UD)),
fs_reg(brw_imm_ud(WRITEMASK_X << 16)),
fs_reg(brw_imm_ud(0)),
};
fs_reg payload = bld.vgrf(BRW_REGISTER_TYPE_UD, 3);
bld.LOAD_PAYLOAD(payload, srcs, 3, 2);
fs_inst *inst = bld.emit(SHADER_OPCODE_URB_WRITE_SIMD8_MASKED,
bld.null_reg_ud(), payload);
inst->mlen = 3;
inst->eot = true;
if (shader_time_index >= 0)
emit_shader_time_end();
if (failed)
return false;
calculate_cfg();
optimize();
assign_curb_setup();
assign_tcs_single_patch_urb_setup();
fixup_3src_null_dest();
allocate_registers(8, true);
return !failed;
}
bool
fs_visitor::run_tes()
{
assert(stage == MESA_SHADER_TESS_EVAL);
/* R0: thread header, R1-3: gl_TessCoord.xyz, R4: URB handles */
payload.num_regs = 5;
if (shader_time_index >= 0)
emit_shader_time_begin();
emit_nir_code();
if (failed)
return false;
emit_urb_writes();
if (shader_time_index >= 0)
emit_shader_time_end();
calculate_cfg();
optimize();
assign_curb_setup();
assign_tes_urb_setup();
fixup_3src_null_dest();
allocate_registers(8, true);
return !failed;
}
bool
fs_visitor::run_gs()
{
assert(stage == MESA_SHADER_GEOMETRY);
setup_gs_payload();
this->final_gs_vertex_count = vgrf(glsl_type::uint_type);
if (gs_compile->control_data_header_size_bits > 0) {
/* Create a VGRF to store accumulated control data bits. */
this->control_data_bits = vgrf(glsl_type::uint_type);
/* If we're outputting more than 32 control data bits, then EmitVertex()
* will set control_data_bits to 0 after emitting the first vertex.
* Otherwise, we need to initialize it to 0 here.
*/
if (gs_compile->control_data_header_size_bits <= 32) {
const fs_builder abld = bld.annotate("initialize control data bits");
abld.MOV(this->control_data_bits, brw_imm_ud(0u));
}
}
if (shader_time_index >= 0)
emit_shader_time_begin();
emit_nir_code();
emit_gs_thread_end();
if (shader_time_index >= 0)
emit_shader_time_end();
if (failed)
return false;
calculate_cfg();
optimize();
assign_curb_setup();
assign_gs_urb_setup();
fixup_3src_null_dest();
allocate_registers(8, true);
return !failed;
}
/* From the SKL PRM, Volume 16, Workarounds:
*
* 0877 3D Pixel Shader Hang possible when pixel shader dispatched with
* only header phases (R0-R2)
*
* WA: Enable a non-header phase (e.g. push constant) when dispatch would
* have been header only.
*
* Instead of enabling push constants one can alternatively enable one of the
* inputs. Here one simply chooses "layer" which shouldn't impose much
* overhead.
*/
static void
gen9_ps_header_only_workaround(struct brw_wm_prog_data *wm_prog_data)
{
if (wm_prog_data->num_varying_inputs)
return;
if (wm_prog_data->base.curb_read_length)
return;
wm_prog_data->urb_setup[VARYING_SLOT_LAYER] = 0;
wm_prog_data->num_varying_inputs = 1;
}
bool
fs_visitor::run_fs(bool allow_spilling, bool do_rep_send)
{
struct brw_wm_prog_data *wm_prog_data = brw_wm_prog_data(this->prog_data);
brw_wm_prog_key *wm_key = (brw_wm_prog_key *) this->key;
assert(stage == MESA_SHADER_FRAGMENT);
if (devinfo->gen >= 6)
setup_fs_payload_gen6();
else
setup_fs_payload_gen4();
if (0) {
emit_dummy_fs();
} else if (do_rep_send) {
assert(dispatch_width == 16);
emit_repclear_shader();
} else {
if (shader_time_index >= 0)
emit_shader_time_begin();
calculate_urb_setup();
if (nir->info.inputs_read > 0 ||
(nir->info.outputs_read > 0 && !wm_key->coherent_fb_fetch)) {
if (devinfo->gen < 6)
emit_interpolation_setup_gen4();
else
emit_interpolation_setup_gen6();
}
/* We handle discards by keeping track of the still-live pixels in f0.1.
* Initialize it with the dispatched pixels.
*/
if (wm_prog_data->uses_kill) {
fs_inst *discard_init = bld.emit(FS_OPCODE_MOV_DISPATCH_TO_FLAGS);
discard_init->flag_subreg = 1;
}
/* Generate FS IR for main(). (the visitor only descends into
* functions called "main").
*/
emit_nir_code();
if (failed)
return false;
if (wm_prog_data->uses_kill)
bld.emit(FS_OPCODE_PLACEHOLDER_HALT);
if (wm_key->alpha_test_func)
emit_alpha_test();
emit_fb_writes();
if (shader_time_index >= 0)
emit_shader_time_end();
calculate_cfg();
optimize();
assign_curb_setup();
if (devinfo->gen >= 9)
gen9_ps_header_only_workaround(wm_prog_data);
assign_urb_setup();
fixup_3src_null_dest();
allocate_registers(8, allow_spilling);
if (failed)
return false;
}
return !failed;
}
bool
fs_visitor::run_cs(unsigned min_dispatch_width)
{
assert(stage == MESA_SHADER_COMPUTE);
assert(dispatch_width >= min_dispatch_width);
setup_cs_payload();
if (shader_time_index >= 0)
emit_shader_time_begin();
if (devinfo->is_haswell && prog_data->total_shared > 0) {
/* Move SLM index from g0.0[27:24] to sr0.1[11:8] */
const fs_builder abld = bld.exec_all().group(1, 0);
abld.MOV(retype(brw_sr0_reg(1), BRW_REGISTER_TYPE_UW),
suboffset(retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_UW), 1));
}
emit_nir_code();
if (failed)
return false;
emit_cs_terminate();
if (shader_time_index >= 0)
emit_shader_time_end();
calculate_cfg();
optimize();
assign_curb_setup();
fixup_3src_null_dest();
allocate_registers(min_dispatch_width, true);
if (failed)
return false;
return !failed;
}
/**
* Return a bitfield where bit n is set if barycentric interpolation mode n
* (see enum brw_barycentric_mode) is needed by the fragment shader.
*
* We examine the load_barycentric intrinsics rather than looking at input
* variables so that we catch interpolateAtCentroid() messages too, which
* also need the BRW_BARYCENTRIC_[NON]PERSPECTIVE_CENTROID mode set up.
*/
static unsigned
brw_compute_barycentric_interp_modes(const struct gen_device_info *devinfo,
const nir_shader *shader)
{
unsigned barycentric_interp_modes = 0;
nir_foreach_function(f, shader) {
if (!f->impl)
continue;
nir_foreach_block(block, f->impl) {
nir_foreach_instr(instr, block) {
if (instr->type != nir_instr_type_intrinsic)
continue;
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
if (intrin->intrinsic != nir_intrinsic_load_interpolated_input)
continue;
/* Ignore WPOS; it doesn't require interpolation. */
if (nir_intrinsic_base(intrin) == VARYING_SLOT_POS)
continue;
intrin = nir_instr_as_intrinsic(intrin->src[0].ssa->parent_instr);
enum glsl_interp_mode interp = (enum glsl_interp_mode)
nir_intrinsic_interp_mode(intrin);
nir_intrinsic_op bary_op = intrin->intrinsic;
enum brw_barycentric_mode bary =
brw_barycentric_mode(interp, bary_op);
barycentric_interp_modes |= 1 << bary;
if (devinfo->needs_unlit_centroid_workaround &&
bary_op == nir_intrinsic_load_barycentric_centroid)
barycentric_interp_modes |= 1 << centroid_to_pixel(bary);
}
}
}
return barycentric_interp_modes;
}
static void
brw_compute_flat_inputs(struct brw_wm_prog_data *prog_data,
const nir_shader *shader)
{
prog_data->flat_inputs = 0;
nir_foreach_variable(var, &shader->inputs) {
int input_index = prog_data->urb_setup[var->data.location];
if (input_index < 0)
continue;
/* flat shading */
if (var->data.interpolation == INTERP_MODE_FLAT)
prog_data->flat_inputs |= (1 << input_index);
}
}
static uint8_t
computed_depth_mode(const nir_shader *shader)
{
if (shader->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
switch (shader->info.fs.depth_layout) {
case FRAG_DEPTH_LAYOUT_NONE:
case FRAG_DEPTH_LAYOUT_ANY:
return BRW_PSCDEPTH_ON;
case FRAG_DEPTH_LAYOUT_GREATER:
return BRW_PSCDEPTH_ON_GE;
case FRAG_DEPTH_LAYOUT_LESS:
return BRW_PSCDEPTH_ON_LE;
case FRAG_DEPTH_LAYOUT_UNCHANGED:
return BRW_PSCDEPTH_OFF;
}
}
return BRW_PSCDEPTH_OFF;
}
/**
* Move load_interpolated_input with simple (payload-based) barycentric modes
* to the top of the program so we don't emit multiple PLNs for the same input.
*
* This works around CSE not being able to handle non-dominating cases
* such as:
*
* if (...) {
* interpolate input
* } else {
* interpolate the same exact input
* }
*
* This should be replaced by global value numbering someday.
*/
static bool
move_interpolation_to_top(nir_shader *nir)
{
bool progress = false;
nir_foreach_function(f, nir) {
if (!f->impl)
continue;
nir_block *top = nir_start_block(f->impl);
exec_node *cursor_node = NULL;
nir_foreach_block(block, f->impl) {
if (block == top)
continue;
nir_foreach_instr_safe(instr, block) {
if (instr->type != nir_instr_type_intrinsic)
continue;
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
if (intrin->intrinsic != nir_intrinsic_load_interpolated_input)
continue;
nir_intrinsic_instr *bary_intrinsic =
nir_instr_as_intrinsic(intrin->src[0].ssa->parent_instr);
nir_intrinsic_op op = bary_intrinsic->intrinsic;
/* Leave interpolateAtSample/Offset() where they are. */
if (op == nir_intrinsic_load_barycentric_at_sample ||
op == nir_intrinsic_load_barycentric_at_offset)
continue;
nir_instr *move[3] = {
&bary_intrinsic->instr,
intrin->src[1].ssa->parent_instr,
instr
};
for (unsigned i = 0; i < ARRAY_SIZE(move); i++) {
if (move[i]->block != top) {
move[i]->block = top;
exec_node_remove(&move[i]->node);
if (cursor_node) {
exec_node_insert_after(cursor_node, &move[i]->node);
} else {
exec_list_push_head(&top->instr_list, &move[i]->node);
}
cursor_node = &move[i]->node;
progress = true;
}
}
}
}
nir_metadata_preserve(f->impl, (nir_metadata)
((unsigned) nir_metadata_block_index |
(unsigned) nir_metadata_dominance));
}
return progress;
}
/**
* Demote per-sample barycentric intrinsics to centroid.
*
* Useful when rendering to a non-multisampled buffer.
*/
static bool
demote_sample_qualifiers(nir_shader *nir)
{
bool progress = true;
nir_foreach_function(f, nir) {
if (!f->impl)
continue;
nir_builder b;
nir_builder_init(&b, f->impl);
nir_foreach_block(block, f->impl) {
nir_foreach_instr_safe(instr, block) {
if (instr->type != nir_instr_type_intrinsic)
continue;
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
if (intrin->intrinsic != nir_intrinsic_load_barycentric_sample &&
intrin->intrinsic != nir_intrinsic_load_barycentric_at_sample)
continue;
b.cursor = nir_before_instr(instr);
nir_ssa_def *centroid =
nir_load_barycentric(&b, nir_intrinsic_load_barycentric_centroid,
nir_intrinsic_interp_mode(intrin));
nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
nir_src_for_ssa(centroid));
nir_instr_remove(instr);
progress = true;
}
}
nir_metadata_preserve(f->impl, (nir_metadata)
((unsigned) nir_metadata_block_index |
(unsigned) nir_metadata_dominance));
}
return progress;
}
/**
* Pre-gen6, the register file of the EUs was shared between threads,
* and each thread used some subset allocated on a 16-register block
* granularity. The unit states wanted these block counts.
*/
static inline int
brw_register_blocks(int reg_count)
{
return ALIGN(reg_count, 16) / 16 - 1;
}
const unsigned *
brw_compile_fs(const struct brw_compiler *compiler, void *log_data,
void *mem_ctx,
const struct brw_wm_prog_key *key,
struct brw_wm_prog_data *prog_data,
const nir_shader *src_shader,
struct gl_program *prog,
int shader_time_index8, int shader_time_index16,
bool allow_spilling,
bool use_rep_send, struct brw_vue_map *vue_map,
char **error_str)
{
const struct gen_device_info *devinfo = compiler->devinfo;
nir_shader *shader = nir_shader_clone(mem_ctx, src_shader);
shader = brw_nir_apply_sampler_key(shader, compiler, &key->tex, true);
brw_nir_lower_fs_inputs(shader, devinfo, key);
brw_nir_lower_fs_outputs(shader);
if (devinfo->gen < 6) {
brw_setup_vue_interpolation(vue_map, shader, prog_data, devinfo);
}
if (!key->multisample_fbo)
NIR_PASS_V(shader, demote_sample_qualifiers);
NIR_PASS_V(shader, move_interpolation_to_top);
shader = brw_postprocess_nir(shader, compiler, true);
/* key->alpha_test_func means simulating alpha testing via discards,
* so the shader definitely kills pixels.
*/
prog_data->uses_kill = shader->info.fs.uses_discard ||
key->alpha_test_func;
prog_data->uses_omask = key->multisample_fbo &&
shader->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_SAMPLE_MASK);
prog_data->computed_depth_mode = computed_depth_mode(shader);
prog_data->computed_stencil =
shader->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_STENCIL);
prog_data->persample_dispatch =
key->multisample_fbo &&
(key->persample_interp ||
(shader->info.system_values_read & (SYSTEM_BIT_SAMPLE_ID |
SYSTEM_BIT_SAMPLE_POS)) ||
shader->info.fs.uses_sample_qualifier ||
shader->info.outputs_read);
prog_data->has_render_target_reads = shader->info.outputs_read != 0ull;
prog_data->early_fragment_tests = shader->info.fs.early_fragment_tests;
prog_data->post_depth_coverage = shader->info.fs.post_depth_coverage;
prog_data->inner_coverage = shader->info.fs.inner_coverage;
prog_data->barycentric_interp_modes =
brw_compute_barycentric_interp_modes(compiler->devinfo, shader);
cfg_t *simd8_cfg = NULL, *simd16_cfg = NULL;
uint8_t simd8_grf_start = 0, simd16_grf_start = 0;
unsigned simd8_grf_used = 0, simd16_grf_used = 0;
fs_visitor v8(compiler, log_data, mem_ctx, key,
&prog_data->base, prog, shader, 8,
shader_time_index8);
if (!v8.run_fs(allow_spilling, false /* do_rep_send */)) {
if (error_str)
*error_str = ralloc_strdup(mem_ctx, v8.fail_msg);
return NULL;
} else if (likely(!(INTEL_DEBUG & DEBUG_NO8))) {
simd8_cfg = v8.cfg;
simd8_grf_start = v8.payload.num_regs;
simd8_grf_used = v8.grf_used;
}
if (v8.max_dispatch_width >= 16 &&
likely(!(INTEL_DEBUG & DEBUG_NO16) || use_rep_send)) {
/* Try a SIMD16 compile */
fs_visitor v16(compiler, log_data, mem_ctx, key,
&prog_data->base, prog, shader, 16,
shader_time_index16);
v16.import_uniforms(&v8);
if (!v16.run_fs(allow_spilling, use_rep_send)) {
compiler->shader_perf_log(log_data,
"SIMD16 shader failed to compile: %s",
v16.fail_msg);
} else {
simd16_cfg = v16.cfg;
simd16_grf_start = v16.payload.num_regs;
simd16_grf_used = v16.grf_used;
}
}
/* When the caller requests a repclear shader, they want SIMD16-only */
if (use_rep_send)
simd8_cfg = NULL;
/* Prior to Iron Lake, the PS had a single shader offset with a jump table
* at the top to select the shader. We've never implemented that.
* Instead, we just give them exactly one shader and we pick the widest one
* available.
*/
if (compiler->devinfo->gen < 5 && simd16_cfg)
simd8_cfg = NULL;
if (prog_data->persample_dispatch) {
/* Starting with SandyBridge (where we first get MSAA), the different
* pixel dispatch combinations are grouped into classifications A
* through F (SNB PRM Vol. 2 Part 1 Section 7.7.1). On all hardware
* generations, the only configurations supporting persample dispatch
* are are this in which only one dispatch width is enabled.
*
* If computed depth is enabled, SNB only allows SIMD8 while IVB+
* allow SIMD8 or SIMD16 so we choose SIMD16 if available.
*/
if (compiler->devinfo->gen == 6 &&
prog_data->computed_depth_mode != BRW_PSCDEPTH_OFF) {
simd16_cfg = NULL;
} else if (simd16_cfg) {
simd8_cfg = NULL;
}
}
/* We have to compute the flat inputs after the visitor is finished running
* because it relies on prog_data->urb_setup which is computed in
* fs_visitor::calculate_urb_setup().
*/
brw_compute_flat_inputs(prog_data, shader);
fs_generator g(compiler, log_data, mem_ctx, (void *) key, &prog_data->base,
v8.promoted_constants, v8.runtime_check_aads_emit,
MESA_SHADER_FRAGMENT);
if (unlikely(INTEL_DEBUG & DEBUG_WM)) {
g.enable_debug(ralloc_asprintf(mem_ctx, "%s fragment shader %s",
shader->info.label ?
shader->info.label : "unnamed",
shader->info.name));
}
if (simd8_cfg) {
prog_data->dispatch_8 = true;
g.generate_code(simd8_cfg, 8);
prog_data->base.dispatch_grf_start_reg = simd8_grf_start;
prog_data->reg_blocks_0 = brw_register_blocks(simd8_grf_used);
if (simd16_cfg) {
prog_data->dispatch_16 = true;
prog_data->prog_offset_2 = g.generate_code(simd16_cfg, 16);
prog_data->dispatch_grf_start_reg_2 = simd16_grf_start;
prog_data->reg_blocks_2 = brw_register_blocks(simd16_grf_used);
}
} else if (simd16_cfg) {
prog_data->dispatch_16 = true;
g.generate_code(simd16_cfg, 16);
prog_data->base.dispatch_grf_start_reg = simd16_grf_start;
prog_data->reg_blocks_0 = brw_register_blocks(simd16_grf_used);
}
return g.get_assembly(&prog_data->base.program_size);
}
fs_reg *
fs_visitor::emit_cs_work_group_id_setup()
{
assert(stage == MESA_SHADER_COMPUTE);
fs_reg *reg = new(this->mem_ctx) fs_reg(vgrf(glsl_type::uvec3_type));
struct brw_reg r0_1(retype(brw_vec1_grf(0, 1), BRW_REGISTER_TYPE_UD));
struct brw_reg r0_6(retype(brw_vec1_grf(0, 6), BRW_REGISTER_TYPE_UD));
struct brw_reg r0_7(retype(brw_vec1_grf(0, 7), BRW_REGISTER_TYPE_UD));
bld.MOV(*reg, r0_1);
bld.MOV(offset(*reg, bld, 1), r0_6);
bld.MOV(offset(*reg, bld, 2), r0_7);
return reg;
}
static void
fill_push_const_block_info(struct brw_push_const_block *block, unsigned dwords)
{
block->dwords = dwords;
block->regs = DIV_ROUND_UP(dwords, 8);
block->size = block->regs * 32;
}
static void
cs_fill_push_const_info(const struct gen_device_info *devinfo,
struct brw_cs_prog_data *cs_prog_data)
{
const struct brw_stage_prog_data *prog_data = &cs_prog_data->base;
int subgroup_id_index = get_subgroup_id_param_index(prog_data);
bool cross_thread_supported = devinfo->gen > 7 || devinfo->is_haswell;
/* The thread ID should be stored in the last param dword */
assert(subgroup_id_index == -1 ||
subgroup_id_index == (int)prog_data->nr_params - 1);
unsigned cross_thread_dwords, per_thread_dwords;
if (!cross_thread_supported) {
cross_thread_dwords = 0u;
per_thread_dwords = prog_data->nr_params;
} else if (subgroup_id_index >= 0) {
/* Fill all but the last register with cross-thread payload */
cross_thread_dwords = 8 * (subgroup_id_index / 8);
per_thread_dwords = prog_data->nr_params - cross_thread_dwords;
assert(per_thread_dwords > 0 && per_thread_dwords <= 8);
} else {
/* Fill all data using cross-thread payload */
cross_thread_dwords = prog_data->nr_params;
per_thread_dwords = 0u;
}
fill_push_const_block_info(&cs_prog_data->push.cross_thread, cross_thread_dwords);
fill_push_const_block_info(&cs_prog_data->push.per_thread, per_thread_dwords);
unsigned total_dwords =
(cs_prog_data->push.per_thread.size * cs_prog_data->threads +
cs_prog_data->push.cross_thread.size) / 4;
fill_push_const_block_info(&cs_prog_data->push.total, total_dwords);
assert(cs_prog_data->push.cross_thread.dwords % 8 == 0 ||
cs_prog_data->push.per_thread.size == 0);
assert(cs_prog_data->push.cross_thread.dwords +
cs_prog_data->push.per_thread.dwords ==
prog_data->nr_params);
}
static void
cs_set_simd_size(struct brw_cs_prog_data *cs_prog_data, unsigned size)
{
cs_prog_data->simd_size = size;
unsigned group_size = cs_prog_data->local_size[0] *
cs_prog_data->local_size[1] * cs_prog_data->local_size[2];
cs_prog_data->threads = (group_size + size - 1) / size;
}
static nir_shader *
compile_cs_to_nir(const struct brw_compiler *compiler,
void *mem_ctx,
const struct brw_cs_prog_key *key,
struct brw_cs_prog_data *prog_data,
const nir_shader *src_shader,
unsigned dispatch_width)
{
nir_shader *shader = nir_shader_clone(mem_ctx, src_shader);
shader = brw_nir_apply_sampler_key(shader, compiler, &key->tex, true);
brw_nir_lower_cs_intrinsics(shader, dispatch_width);
return brw_postprocess_nir(shader, compiler, true);
}
const unsigned *
brw_compile_cs(const struct brw_compiler *compiler, void *log_data,
void *mem_ctx,
const struct brw_cs_prog_key *key,
struct brw_cs_prog_data *prog_data,
const nir_shader *src_shader,
int shader_time_index,
char **error_str)
{
prog_data->local_size[0] = src_shader->info.cs.local_size[0];
prog_data->local_size[1] = src_shader->info.cs.local_size[1];
prog_data->local_size[2] = src_shader->info.cs.local_size[2];
unsigned local_workgroup_size =
src_shader->info.cs.local_size[0] * src_shader->info.cs.local_size[1] *
src_shader->info.cs.local_size[2];
unsigned min_dispatch_width =
DIV_ROUND_UP(local_workgroup_size, compiler->devinfo->max_cs_threads);
min_dispatch_width = MAX2(8, min_dispatch_width);
min_dispatch_width = util_next_power_of_two(min_dispatch_width);
assert(min_dispatch_width <= 32);
fs_visitor *v8 = NULL, *v16 = NULL, *v32 = NULL;
cfg_t *cfg = NULL;
const char *fail_msg = NULL;
unsigned promoted_constants = 0;
/* Now the main event: Visit the shader IR and generate our CS IR for it.
*/
if (min_dispatch_width <= 8) {
nir_shader *nir8 = compile_cs_to_nir(compiler, mem_ctx, key,
prog_data, src_shader, 8);
v8 = new fs_visitor(compiler, log_data, mem_ctx, key, &prog_data->base,
NULL, /* Never used in core profile */
nir8, 8, shader_time_index);
if (!v8->run_cs(min_dispatch_width)) {
fail_msg = v8->fail_msg;
} else {
/* We should always be able to do SIMD32 for compute shaders */
assert(v8->max_dispatch_width >= 32);
cfg = v8->cfg;
cs_set_simd_size(prog_data, 8);
cs_fill_push_const_info(compiler->devinfo, prog_data);
promoted_constants = v8->promoted_constants;
}
}
if (likely(!(INTEL_DEBUG & DEBUG_NO16)) &&
!fail_msg && min_dispatch_width <= 16) {
/* Try a SIMD16 compile */
nir_shader *nir16 = compile_cs_to_nir(compiler, mem_ctx, key,
prog_data, src_shader, 16);
v16 = new fs_visitor(compiler, log_data, mem_ctx, key, &prog_data->base,
NULL, /* Never used in core profile */
nir16, 16, shader_time_index);
if (v8)
v16->import_uniforms(v8);
if (!v16->run_cs(min_dispatch_width)) {
compiler->shader_perf_log(log_data,
"SIMD16 shader failed to compile: %s",
v16->fail_msg);
if (!cfg) {
fail_msg =
"Couldn't generate SIMD16 program and not "
"enough threads for SIMD8";
}
} else {
/* We should always be able to do SIMD32 for compute shaders */
assert(v16->max_dispatch_width >= 32);
cfg = v16->cfg;
cs_set_simd_size(prog_data, 16);
cs_fill_push_const_info(compiler->devinfo, prog_data);
promoted_constants = v16->promoted_constants;
}
}
/* We should always be able to do SIMD32 for compute shaders */
assert(!v16 || v16->max_dispatch_width >= 32);
if (!fail_msg && (min_dispatch_width > 16 || (INTEL_DEBUG & DEBUG_DO32))) {
/* Try a SIMD32 compile */
nir_shader *nir32 = compile_cs_to_nir(compiler, mem_ctx, key,
prog_data, src_shader, 32);
v32 = new fs_visitor(compiler, log_data, mem_ctx, key, &prog_data->base,
NULL, /* Never used in core profile */
nir32, 32, shader_time_index);
if (v8)
v32->import_uniforms(v8);
else if (v16)
v32->import_uniforms(v16);
if (!v32->run_cs(min_dispatch_width)) {
compiler->shader_perf_log(log_data,
"SIMD32 shader failed to compile: %s",
v16->fail_msg);
if (!cfg) {
fail_msg =
"Couldn't generate SIMD32 program and not "
"enough threads for SIMD16";
}
} else {
cfg = v32->cfg;
cs_set_simd_size(prog_data, 32);
cs_fill_push_const_info(compiler->devinfo, prog_data);
promoted_constants = v32->promoted_constants;
}
}
const unsigned *ret = NULL;
if (unlikely(cfg == NULL)) {
assert(fail_msg);
if (error_str)
*error_str = ralloc_strdup(mem_ctx, fail_msg);
} else {
fs_generator g(compiler, log_data, mem_ctx, (void*) key, &prog_data->base,
promoted_constants, false, MESA_SHADER_COMPUTE);
if (INTEL_DEBUG & DEBUG_CS) {
char *name = ralloc_asprintf(mem_ctx, "%s compute shader %s",
src_shader->info.label ?
src_shader->info.label : "unnamed",
src_shader->info.name);
g.enable_debug(name);
}
g.generate_code(cfg, prog_data->simd_size);
ret = g.get_assembly(&prog_data->base.program_size);
}
delete v8;
delete v16;
delete v32;
return ret;
}
/**
* Test the dispatch mask packing assumptions of
* brw_stage_has_packed_dispatch(). Call this from e.g. the top of
* fs_visitor::emit_nir_code() to cause a GPU hang if any shader invocation is
* executed with an unexpected dispatch mask.
*/
static UNUSED void
brw_fs_test_dispatch_packing(const fs_builder &bld)
{
const gl_shader_stage stage = bld.shader->stage;
if (brw_stage_has_packed_dispatch(bld.shader->devinfo, stage,
bld.shader->stage_prog_data)) {
const fs_builder ubld = bld.exec_all().group(1, 0);
const fs_reg tmp = component(bld.vgrf(BRW_REGISTER_TYPE_UD), 0);
const fs_reg mask = (stage == MESA_SHADER_FRAGMENT ? brw_vmask_reg() :
brw_dmask_reg());
ubld.ADD(tmp, mask, brw_imm_ud(1));
ubld.AND(tmp, mask, tmp);
/* This will loop forever if the dispatch mask doesn't have the expected
* form '2^n-1', in which case tmp will be non-zero.
*/
bld.emit(BRW_OPCODE_DO);
bld.CMP(bld.null_reg_ud(), tmp, brw_imm_ud(0), BRW_CONDITIONAL_NZ);
set_predicate(BRW_PREDICATE_NORMAL, bld.emit(BRW_OPCODE_WHILE));
}
}