/**************************************************************************
*
* Copyright 2009 VMware, Inc.
* All Rights Reserved.
*
* 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, sub license, 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 NON-INFRINGEMENT.
* IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS 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
* Helper functions for type conversions.
*
* We want to use the fastest type for a given computation whenever feasible.
* The other side of this is that we need to be able convert between several
* types accurately and efficiently.
*
* Conversion between types of different bit width is quite complex since a
*
* To remember there are a few invariants in type conversions:
*
* - register width must remain constant:
*
* src_type.width * src_type.length == dst_type.width * dst_type.length
*
* - total number of elements must remain constant:
*
* src_type.length * num_srcs == dst_type.length * num_dsts
*
* It is not always possible to do the conversion both accurately and
* efficiently, usually due to lack of adequate machine instructions. In these
* cases it is important not to cut shortcuts here and sacrifice accuracy, as
* there this functions can be used anywhere. In the future we might have a
* precision parameter which can gauge the accuracy vs efficiency compromise,
* but for now if the data conversion between two stages happens to be the
* bottleneck, then most likely should just avoid converting at all and run
* both stages with the same type.
*
* Make sure to run lp_test_conv unit test after any change to this file.
*
* @author Jose Fonseca <jfonseca@vmware.com>
*/
#include "util/u_debug.h"
#include "util/u_math.h"
#include "util/u_half.h"
#include "util/u_cpu_detect.h"
#include "lp_bld_type.h"
#include "lp_bld_const.h"
#include "lp_bld_arit.h"
#include "lp_bld_bitarit.h"
#include "lp_bld_pack.h"
#include "lp_bld_conv.h"
#include "lp_bld_logic.h"
#include "lp_bld_intr.h"
#include "lp_bld_printf.h"
#include "lp_bld_format.h"
/**
* Converts int16 half-float to float32
* Note this can be performed in 1 instruction if vcvtph2ps exists (f16c/cvt16)
* [llvm.x86.vcvtph2ps / _mm_cvtph_ps]
*
* @param src value to convert
*
*/
LLVMValueRef
lp_build_half_to_float(struct gallivm_state *gallivm,
LLVMValueRef src)
{
LLVMBuilderRef builder = gallivm->builder;
LLVMTypeRef src_type = LLVMTypeOf(src);
unsigned src_length = LLVMGetTypeKind(src_type) == LLVMVectorTypeKind ?
LLVMGetVectorSize(src_type) : 1;
struct lp_type f32_type = lp_type_float_vec(32, 32 * src_length);
struct lp_type i32_type = lp_type_int_vec(32, 32 * src_length);
LLVMTypeRef int_vec_type = lp_build_vec_type(gallivm, i32_type);
LLVMValueRef h;
if (util_cpu_caps.has_f16c &&
(src_length == 4 || src_length == 8)) {
const char *intrinsic = NULL;
if (src_length == 4) {
src = lp_build_pad_vector(gallivm, src, 8);
intrinsic = "llvm.x86.vcvtph2ps.128";
}
else {
intrinsic = "llvm.x86.vcvtph2ps.256";
}
return lp_build_intrinsic_unary(builder, intrinsic,
lp_build_vec_type(gallivm, f32_type), src);
}
/* Convert int16 vector to int32 vector by zero ext (might generate bad code) */
h = LLVMBuildZExt(builder, src, int_vec_type, "");
return lp_build_smallfloat_to_float(gallivm, f32_type, h, 10, 5, 0, true);
}
/**
* Converts float32 to int16 half-float
* Note this can be performed in 1 instruction if vcvtps2ph exists (f16c/cvt16)
* [llvm.x86.vcvtps2ph / _mm_cvtps_ph]
*
* @param src value to convert
*
* Convert float32 to half floats, preserving Infs and NaNs,
* with rounding towards zero (trunc).
* XXX: For GL, would prefer rounding towards nearest(-even).
*/
LLVMValueRef
lp_build_float_to_half(struct gallivm_state *gallivm,
LLVMValueRef src)
{
LLVMBuilderRef builder = gallivm->builder;
LLVMTypeRef f32_vec_type = LLVMTypeOf(src);
unsigned length = LLVMGetTypeKind(f32_vec_type) == LLVMVectorTypeKind
? LLVMGetVectorSize(f32_vec_type) : 1;
struct lp_type i32_type = lp_type_int_vec(32, 32 * length);
struct lp_type i16_type = lp_type_int_vec(16, 16 * length);
LLVMValueRef result;
/*
* Note: Newer llvm versions (3.6 or so) support fptrunc to 16 bits
* directly, without any (x86 or generic) intrinsics.
* Albeit the rounding mode cannot be specified (and is undefined,
* though in practice on x86 seems to do nearest-even but it may
* be dependent on instruction set support), so is essentially
* useless.
*/
if (util_cpu_caps.has_f16c &&
(length == 4 || length == 8)) {
struct lp_type i168_type = lp_type_int_vec(16, 16 * 8);
unsigned mode = 3; /* same as LP_BUILD_ROUND_TRUNCATE */
LLVMTypeRef i32t = LLVMInt32TypeInContext(gallivm->context);
const char *intrinsic = NULL;
if (length == 4) {
intrinsic = "llvm.x86.vcvtps2ph.128";
}
else {
intrinsic = "llvm.x86.vcvtps2ph.256";
}
result = lp_build_intrinsic_binary(builder, intrinsic,
lp_build_vec_type(gallivm, i168_type),
src, LLVMConstInt(i32t, mode, 0));
if (length == 4) {
result = lp_build_extract_range(gallivm, result, 0, 4);
}
}
else {
result = lp_build_float_to_smallfloat(gallivm, i32_type, src, 10, 5, 0, true);
/* Convert int32 vector to int16 vector by trunc (might generate bad code) */
result = LLVMBuildTrunc(builder, result, lp_build_vec_type(gallivm, i16_type), "");
}
/*
* Debugging code.
*/
if (0) {
LLVMTypeRef i32t = LLVMInt32TypeInContext(gallivm->context);
LLVMTypeRef i16t = LLVMInt16TypeInContext(gallivm->context);
LLVMTypeRef f32t = LLVMFloatTypeInContext(gallivm->context);
LLVMValueRef ref_result = LLVMGetUndef(LLVMVectorType(i16t, length));
unsigned i;
LLVMTypeRef func_type = LLVMFunctionType(i16t, &f32t, 1, 0);
LLVMValueRef func = lp_build_const_int_pointer(gallivm, func_to_pointer((func_pointer)util_float_to_half));
func = LLVMBuildBitCast(builder, func, LLVMPointerType(func_type, 0), "util_float_to_half");
for (i = 0; i < length; ++i) {
LLVMValueRef index = LLVMConstInt(i32t, i, 0);
LLVMValueRef f32 = LLVMBuildExtractElement(builder, src, index, "");
#if 0
/*
* XXX: not really supported by backends.
* Even if they would now, rounding mode cannot be specified and
* is undefined.
*/
LLVMValueRef f16 = lp_build_intrinsic_unary(builder, "llvm.convert.to.fp16", i16t, f32);
#else
LLVMValueRef f16 = LLVMBuildCall(builder, func, &f32, 1, "");
#endif
ref_result = LLVMBuildInsertElement(builder, ref_result, f16, index, "");
}
lp_build_print_value(gallivm, "src = ", src);
lp_build_print_value(gallivm, "llvm = ", result);
lp_build_print_value(gallivm, "util = ", ref_result);
lp_build_printf(gallivm, "\n");
}
return result;
}
/**
* Special case for converting clamped IEEE-754 floats to unsigned norms.
*
* The mathematical voodoo below may seem excessive but it is actually
* paramount we do it this way for several reasons. First, there is no single
* precision FP to unsigned integer conversion Intel SSE instruction. Second,
* secondly, even if there was, since the FP's mantissa takes only a fraction
* of register bits the typically scale and cast approach would require double
* precision for accurate results, and therefore half the throughput
*
* Although the result values can be scaled to an arbitrary bit width specified
* by dst_width, the actual result type will have the same width.
*
* Ex: src = { float, float, float, float }
* return { i32, i32, i32, i32 } where each value is in [0, 2^dst_width-1].
*/
LLVMValueRef
lp_build_clamped_float_to_unsigned_norm(struct gallivm_state *gallivm,
struct lp_type src_type,
unsigned dst_width,
LLVMValueRef src)
{
LLVMBuilderRef builder = gallivm->builder;
LLVMTypeRef int_vec_type = lp_build_int_vec_type(gallivm, src_type);
LLVMValueRef res;
unsigned mantissa;
assert(src_type.floating);
assert(dst_width <= src_type.width);
src_type.sign = FALSE;
mantissa = lp_mantissa(src_type);
if (dst_width <= mantissa) {
/*
* Apply magic coefficients that will make the desired result to appear
* in the lowest significant bits of the mantissa, with correct rounding.
*
* This only works if the destination width fits in the mantissa.
*/
unsigned long long ubound;
unsigned long long mask;
double scale;
double bias;
ubound = (1ULL << dst_width);
mask = ubound - 1;
scale = (double)mask/ubound;
bias = (double)(1ULL << (mantissa - dst_width));
res = LLVMBuildFMul(builder, src, lp_build_const_vec(gallivm, src_type, scale), "");
/* instead of fadd/and could (with sse2) just use lp_build_iround */
res = LLVMBuildFAdd(builder, res, lp_build_const_vec(gallivm, src_type, bias), "");
res = LLVMBuildBitCast(builder, res, int_vec_type, "");
res = LLVMBuildAnd(builder, res,
lp_build_const_int_vec(gallivm, src_type, mask), "");
}
else if (dst_width == (mantissa + 1)) {
/*
* The destination width matches exactly what can be represented in
* floating point (i.e., mantissa + 1 bits). Even so correct rounding
* still needs to be applied (only for numbers in [0.5-1.0] would
* conversion using truncation after scaling be sufficient).
*/
double scale;
struct lp_build_context uf32_bld;
lp_build_context_init(&uf32_bld, gallivm, src_type);
scale = (double)((1ULL << dst_width) - 1);
res = LLVMBuildFMul(builder, src,
lp_build_const_vec(gallivm, src_type, scale), "");
res = lp_build_iround(&uf32_bld, res);
}
else {
/*
* The destination exceeds what can be represented in the floating point.
* So multiply by the largest power two we get away with, and when
* subtract the most significant bit to rescale to normalized values.
*
* The largest power of two factor we can get away is
* (1 << (src_type.width - 1)), because we need to use signed . In theory it
* should be (1 << (src_type.width - 2)), but IEEE 754 rules states
* INT_MIN should be returned in FPToSI, which is the correct result for
* values near 1.0!
*
* This means we get (src_type.width - 1) correct bits for values near 0.0,
* and (mantissa + 1) correct bits for values near 1.0. Equally or more
* important, we also get exact results for 0.0 and 1.0.
*/
unsigned n = MIN2(src_type.width - 1u, dst_width);
double scale = (double)(1ULL << n);
unsigned lshift = dst_width - n;
unsigned rshift = n;
LLVMValueRef lshifted;
LLVMValueRef rshifted;
res = LLVMBuildFMul(builder, src,
lp_build_const_vec(gallivm, src_type, scale), "");
res = LLVMBuildFPToSI(builder, res, int_vec_type, "");
/*
* Align the most significant bit to its final place.
*
* This will cause 1.0 to overflow to 0, but the later adjustment will
* get it right.
*/
if (lshift) {
lshifted = LLVMBuildShl(builder, res,
lp_build_const_int_vec(gallivm, src_type,
lshift), "");
} else {
lshifted = res;
}
/*
* Align the most significant bit to the right.
*/
rshifted = LLVMBuildLShr(builder, res,
lp_build_const_int_vec(gallivm, src_type, rshift),
"");
/*
* Subtract the MSB to the LSB, therefore re-scaling from
* (1 << dst_width) to ((1 << dst_width) - 1).
*/
res = LLVMBuildSub(builder, lshifted, rshifted, "");
}
return res;
}
/**
* Inverse of lp_build_clamped_float_to_unsigned_norm above.
* Ex: src = { i32, i32, i32, i32 } with values in range [0, 2^src_width-1]
* return {float, float, float, float} with values in range [0, 1].
*/
LLVMValueRef
lp_build_unsigned_norm_to_float(struct gallivm_state *gallivm,
unsigned src_width,
struct lp_type dst_type,
LLVMValueRef src)
{
LLVMBuilderRef builder = gallivm->builder;
LLVMTypeRef vec_type = lp_build_vec_type(gallivm, dst_type);
LLVMTypeRef int_vec_type = lp_build_int_vec_type(gallivm, dst_type);
LLVMValueRef bias_;
LLVMValueRef res;
unsigned mantissa;
unsigned n;
unsigned long long ubound;
unsigned long long mask;
double scale;
double bias;
assert(dst_type.floating);
mantissa = lp_mantissa(dst_type);
if (src_width <= (mantissa + 1)) {
/*
* The source width matches fits what can be represented in floating
* point (i.e., mantissa + 1 bits). So do a straight multiplication
* followed by casting. No further rounding is necessary.
*/
scale = 1.0/(double)((1ULL << src_width) - 1);
res = LLVMBuildSIToFP(builder, src, vec_type, "");
res = LLVMBuildFMul(builder, res,
lp_build_const_vec(gallivm, dst_type, scale), "");
return res;
}
else {
/*
* The source width exceeds what can be represented in floating
* point. So truncate the incoming values.
*/
n = MIN2(mantissa, src_width);
ubound = ((unsigned long long)1 << n);
mask = ubound - 1;
scale = (double)ubound/mask;
bias = (double)((unsigned long long)1 << (mantissa - n));
res = src;
if (src_width > mantissa) {
int shift = src_width - mantissa;
res = LLVMBuildLShr(builder, res,
lp_build_const_int_vec(gallivm, dst_type, shift), "");
}
bias_ = lp_build_const_vec(gallivm, dst_type, bias);
res = LLVMBuildOr(builder,
res,
LLVMBuildBitCast(builder, bias_, int_vec_type, ""), "");
res = LLVMBuildBitCast(builder, res, vec_type, "");
res = LLVMBuildFSub(builder, res, bias_, "");
res = LLVMBuildFMul(builder, res, lp_build_const_vec(gallivm, dst_type, scale), "");
}
return res;
}
/**
* Pick a suitable num_dsts for lp_build_conv to ensure optimal cases are used.
*
* Returns the number of dsts created from src
*/
int lp_build_conv_auto(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type* dst_type,
const LLVMValueRef *src,
unsigned num_srcs,
LLVMValueRef *dst)
{
unsigned i;
int num_dsts = num_srcs;
if (src_type.floating == dst_type->floating &&
src_type.width == dst_type->width &&
src_type.length == dst_type->length &&
src_type.fixed == dst_type->fixed &&
src_type.norm == dst_type->norm &&
src_type.sign == dst_type->sign)
return num_dsts;
/* Special case 4x4x32 -> 1x16x8 or 2x8x32 -> 1x16x8
*/
if (src_type.norm == 0 &&
src_type.width == 32 &&
src_type.fixed == 0 &&
dst_type->floating == 0 &&
dst_type->fixed == 0 &&
dst_type->width == 8 &&
((src_type.floating == 1 && src_type.sign == 1 && dst_type->norm == 1) ||
(src_type.floating == 0 && dst_type->floating == 0 &&
src_type.sign == dst_type->sign && dst_type->norm == 0))) {
/* Special case 4x4x32 --> 1x16x8 */
if (src_type.length == 4 &&
(util_cpu_caps.has_sse2 || util_cpu_caps.has_altivec))
{
num_dsts = (num_srcs + 3) / 4;
dst_type->length = num_srcs * 4 >= 16 ? 16 : num_srcs * 4;
lp_build_conv(gallivm, src_type, *dst_type, src, num_srcs, dst, num_dsts);
return num_dsts;
}
/* Special case 2x8x32 --> 1x16x8 */
if (src_type.length == 8 &&
util_cpu_caps.has_avx)
{
num_dsts = (num_srcs + 1) / 2;
dst_type->length = num_srcs * 8 >= 16 ? 16 : num_srcs * 8;
lp_build_conv(gallivm, src_type, *dst_type, src, num_srcs, dst, num_dsts);
return num_dsts;
}
}
/* lp_build_resize does not support M:N */
if (src_type.width == dst_type->width) {
lp_build_conv(gallivm, src_type, *dst_type, src, num_srcs, dst, num_dsts);
} else {
/*
* If dst_width is 16 bits and src_width 32 and the dst vector size
* 64bit, try feeding 2 vectors at once so pack intrinsics can be used.
* (For AVX, this isn't needed, since we usually get 256bit src and
* 128bit dst vectors which works ok. If we do AVX2 pack this should
* be extended but need to be able to tell conversion code about pack
* ordering first.)
*/
unsigned ratio = 1;
if (src_type.width == 2 * dst_type->width &&
src_type.length == dst_type->length &&
dst_type->floating == 0 && (num_srcs % 2 == 0) &&
dst_type->width * dst_type->length == 64) {
ratio = 2;
num_dsts /= 2;
dst_type->length *= 2;
}
for (i = 0; i < num_dsts; i++) {
lp_build_conv(gallivm, src_type, *dst_type, &src[i*ratio], ratio, &dst[i], 1);
}
}
return num_dsts;
}
/**
* Generic type conversion.
*
* TODO: Take a precision argument, or even better, add a new precision member
* to the lp_type union.
*/
void
lp_build_conv(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type dst_type,
const LLVMValueRef *src, unsigned num_srcs,
LLVMValueRef *dst, unsigned num_dsts)
{
LLVMBuilderRef builder = gallivm->builder;
struct lp_type tmp_type;
LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH];
unsigned num_tmps;
unsigned i;
/* We must not loose or gain channels. Only precision */
assert(src_type.length * num_srcs == dst_type.length * num_dsts);
assert(src_type.length <= LP_MAX_VECTOR_LENGTH);
assert(dst_type.length <= LP_MAX_VECTOR_LENGTH);
assert(num_srcs <= LP_MAX_VECTOR_LENGTH);
assert(num_dsts <= LP_MAX_VECTOR_LENGTH);
tmp_type = src_type;
for(i = 0; i < num_srcs; ++i) {
assert(lp_check_value(src_type, src[i]));
tmp[i] = src[i];
}
num_tmps = num_srcs;
/*
* Special case 4x4x32 --> 1x16x8, 2x4x32 -> 1x8x8, 1x4x32 -> 1x4x8
* Only float -> s/unorm8 and (u)int32->(u)int8.
* XXX: This should cover all interesting backend cases for 8 bit,
* but should use same strategy if dst is 16 bit.
*/
if (src_type.norm == 0 &&
src_type.width == 32 &&
src_type.length == 4 &&
src_type.fixed == 0 &&
dst_type.floating == 0 &&
dst_type.fixed == 0 &&
dst_type.width == 8 &&
((src_type.floating == 1 && src_type.sign == 1 && dst_type.norm == 1) ||
(src_type.floating == 0 && dst_type.floating == 0 &&
src_type.sign == dst_type.sign && dst_type.norm == 0)) &&
((dst_type.length == 16 && 4 * num_dsts == num_srcs) ||
(num_dsts == 1 && dst_type.length * num_srcs == 16 && num_srcs != 3)) &&
(util_cpu_caps.has_sse2 || util_cpu_caps.has_altivec))
{
struct lp_build_context bld;
struct lp_type int16_type, int32_type;
struct lp_type dst_type_ext = dst_type;
LLVMValueRef const_scale;
unsigned i, j;
lp_build_context_init(&bld, gallivm, src_type);
dst_type_ext.length = 16;
int16_type = int32_type = dst_type_ext;
int16_type.width *= 2;
int16_type.length /= 2;
int16_type.sign = 1;
int32_type.width *= 4;
int32_type.length /= 4;
int32_type.sign = 1;
const_scale = lp_build_const_vec(gallivm, src_type, lp_const_scale(dst_type));
for (i = 0; i < num_dsts; ++i, src += 4) {
LLVMValueRef lo, hi;
if (src_type.floating) {
for (j = 0; j < dst_type.length / 4; ++j) {
/*
* XXX This is not actually fully correct. The float to int
* conversion will produce 0x80000000 value for everything
* out of range and NaNs (on x86, llvm.x86.sse2.cvtps2dq).
* Hence, NaNs and negatives will get clamped just fine to zero
* (relying on clamping pack behavior) when converting to unorm,
* however too large values (both finite and infinite) will also
* end up as zero, not 255.
* For snorm, for now we'll keep bug compatibility with generic
* conversion path (meaning too large values are fine, but
* NaNs get converted to -128 (purely by luck, as we don't
* specify nan behavior for the max there) instead of 0).
*/
if (dst_type.sign) {
tmp[j] = lp_build_min(&bld, bld.one, src[j]);
}
else {
if (0) {
tmp[j] = lp_build_min_ext(&bld, bld.one, src[j],
GALLIVM_NAN_RETURN_NAN_FIRST_NONNAN);
}
tmp[j] = src[j];
}
tmp[j] = LLVMBuildFMul(builder, tmp[j], const_scale, "");
tmp[j] = lp_build_iround(&bld, tmp[j]);
}
} else {
for (j = 0; j < dst_type.length / 4; ++j) {
if (!dst_type.sign) {
/*
* Pack clamp is always signed->unsigned (or signed->signed).
* Hence need min.
*/
LLVMValueRef const_max;
const_max = lp_build_const_int_vec(gallivm, src_type, 255);
tmp[j] = lp_build_min(&bld, src[j], const_max);
} else {
tmp[j] = src[j];
}
}
}
if (num_srcs == 1) {
tmp[1] = tmp[0];
}
/* relying on clamping behavior of sse2 intrinsics here */
lo = lp_build_pack2(gallivm, int32_type, int16_type, tmp[0], tmp[1]);
if (num_srcs < 4) {
hi = lo;
}
else {
hi = lp_build_pack2(gallivm, int32_type, int16_type, tmp[2], tmp[3]);
}
dst[i] = lp_build_pack2(gallivm, int16_type, dst_type_ext, lo, hi);
}
if (num_srcs < 4) {
dst[0] = lp_build_extract_range(gallivm, dst[0], 0, dst_type.length);
}
return;
}
/* Special case 2x8x32 --> 1x16x8, 1x8x32 ->1x8x8
*/
else if (src_type.norm == 0 &&
src_type.width == 32 &&
src_type.length == 8 &&
src_type.fixed == 0 &&
dst_type.floating == 0 &&
dst_type.fixed == 0 &&
dst_type.width == 8 &&
((src_type.floating == 1 && src_type.sign == 1 && dst_type.norm == 1) ||
(src_type.floating == 0 && dst_type.floating == 0 &&
src_type.sign == dst_type.sign && dst_type.norm == 0)) &&
((dst_type.length == 16 && 2 * num_dsts == num_srcs) ||
(num_dsts == 1 && dst_type.length * num_srcs == 8)) &&
util_cpu_caps.has_avx) {
struct lp_build_context bld;
struct lp_type int16_type, int32_type;
struct lp_type dst_type_ext = dst_type;
LLVMValueRef const_scale;
unsigned i;
lp_build_context_init(&bld, gallivm, src_type);
dst_type_ext.length = 16;
int16_type = int32_type = dst_type_ext;
int16_type.width *= 2;
int16_type.length /= 2;
int16_type.sign = 1;
int32_type.width *= 4;
int32_type.length /= 4;
int32_type.sign = 1;
const_scale = lp_build_const_vec(gallivm, src_type, lp_const_scale(dst_type));
for (i = 0; i < num_dsts; ++i, src += 2) {
unsigned j;
for (j = 0; j < (num_srcs == 1 ? 1 : 2); j++) {
LLVMValueRef lo, hi, a;
a = src[j];
if (src_type.floating) {
if (dst_type.sign) {
a = lp_build_min(&bld, bld.one, a);
}
else {
if (0) {
a = lp_build_min_ext(&bld, bld.one, a,
GALLIVM_NAN_RETURN_NAN_FIRST_NONNAN);
}
}
a = LLVMBuildFMul(builder, a, const_scale, "");
a = lp_build_iround(&bld, a);
} else {
if (!dst_type.sign) {
LLVMValueRef const_max;
const_max = lp_build_const_int_vec(gallivm, src_type, 255);
a = lp_build_min(&bld, a, const_max);
}
}
lo = lp_build_extract_range(gallivm, a, 0, 4);
hi = lp_build_extract_range(gallivm, a, 4, 4);
/* relying on clamping behavior of sse2 intrinsics here */
tmp[j] = lp_build_pack2(gallivm, int32_type, int16_type, lo, hi);
}
if (num_srcs == 1) {
tmp[1] = tmp[0];
}
dst[i] = lp_build_pack2(gallivm, int16_type, dst_type_ext, tmp[0], tmp[1]);
}
if (num_srcs == 1) {
dst[0] = lp_build_extract_range(gallivm, dst[0], 0, dst_type.length);
}
return;
}
/* Special case -> 16bit half-float
*/
else if (dst_type.floating && dst_type.width == 16)
{
/* Only support src as 32bit float currently */
assert(src_type.floating && src_type.width == 32);
for(i = 0; i < num_tmps; ++i)
dst[i] = lp_build_float_to_half(gallivm, tmp[i]);
return;
}
/* Pre convert half-floats to floats
*/
else if (src_type.floating && src_type.width == 16)
{
for(i = 0; i < num_tmps; ++i)
tmp[i] = lp_build_half_to_float(gallivm, tmp[i]);
tmp_type.width = 32;
}
/*
* Clamp if necessary
*/
if(memcmp(&src_type, &dst_type, sizeof src_type) != 0) {
struct lp_build_context bld;
double src_min = lp_const_min(src_type);
double dst_min = lp_const_min(dst_type);
double src_max = lp_const_max(src_type);
double dst_max = lp_const_max(dst_type);
LLVMValueRef thres;
lp_build_context_init(&bld, gallivm, tmp_type);
if(src_min < dst_min) {
if(dst_min == 0.0)
thres = bld.zero;
else
thres = lp_build_const_vec(gallivm, src_type, dst_min);
for(i = 0; i < num_tmps; ++i)
tmp[i] = lp_build_max(&bld, tmp[i], thres);
}
if(src_max > dst_max) {
if(dst_max == 1.0)
thres = bld.one;
else
thres = lp_build_const_vec(gallivm, src_type, dst_max);
for(i = 0; i < num_tmps; ++i)
tmp[i] = lp_build_min(&bld, tmp[i], thres);
}
}
/*
* Scale to the narrowest range
*/
if(dst_type.floating) {
/* Nothing to do */
}
else if(tmp_type.floating) {
if(!dst_type.fixed && !dst_type.sign && dst_type.norm) {
for(i = 0; i < num_tmps; ++i) {
tmp[i] = lp_build_clamped_float_to_unsigned_norm(gallivm,
tmp_type,
dst_type.width,
tmp[i]);
}
tmp_type.floating = FALSE;
}
else {
double dst_scale = lp_const_scale(dst_type);
if (dst_scale != 1.0) {
LLVMValueRef scale = lp_build_const_vec(gallivm, tmp_type, dst_scale);
for(i = 0; i < num_tmps; ++i)
tmp[i] = LLVMBuildFMul(builder, tmp[i], scale, "");
}
/*
* these functions will use fptosi in some form which won't work
* with 32bit uint dst. Causes lp_test_conv failures though.
*/
if (0)
assert(dst_type.sign || dst_type.width < 32);
if (dst_type.sign && dst_type.norm && !dst_type.fixed) {
struct lp_build_context bld;
lp_build_context_init(&bld, gallivm, tmp_type);
for(i = 0; i < num_tmps; ++i) {
tmp[i] = lp_build_iround(&bld, tmp[i]);
}
tmp_type.floating = FALSE;
}
else {
LLVMTypeRef tmp_vec_type;
tmp_type.floating = FALSE;
tmp_vec_type = lp_build_vec_type(gallivm, tmp_type);
for(i = 0; i < num_tmps; ++i) {
#if 0
if(dst_type.sign)
tmp[i] = LLVMBuildFPToSI(builder, tmp[i], tmp_vec_type, "");
else
tmp[i] = LLVMBuildFPToUI(builder, tmp[i], tmp_vec_type, "");
#else
/* FIXME: there is no SSE counterpart for LLVMBuildFPToUI */
tmp[i] = LLVMBuildFPToSI(builder, tmp[i], tmp_vec_type, "");
#endif
}
}
}
}
else {
unsigned src_shift = lp_const_shift(src_type);
unsigned dst_shift = lp_const_shift(dst_type);
unsigned src_offset = lp_const_offset(src_type);
unsigned dst_offset = lp_const_offset(dst_type);
struct lp_build_context bld;
lp_build_context_init(&bld, gallivm, tmp_type);
/* Compensate for different offsets */
/* sscaled -> unorm and similar would cause negative shift count, skip */
if (dst_offset > src_offset && src_type.width > dst_type.width && src_shift > 0) {
for (i = 0; i < num_tmps; ++i) {
LLVMValueRef shifted;
shifted = lp_build_shr_imm(&bld, tmp[i], src_shift - 1);
tmp[i] = LLVMBuildSub(builder, tmp[i], shifted, "");
}
}
if(src_shift > dst_shift) {
for(i = 0; i < num_tmps; ++i)
tmp[i] = lp_build_shr_imm(&bld, tmp[i], src_shift - dst_shift);
}
}
/*
* Truncate or expand bit width
*
* No data conversion should happen here, although the sign bits are
* crucial to avoid bad clamping.
*/
{
struct lp_type new_type;
new_type = tmp_type;
new_type.sign = dst_type.sign;
new_type.width = dst_type.width;
new_type.length = dst_type.length;
/*
* Note that resize when using packs can sometimes get min/max
* clamping for free. Should be able to exploit this...
*/
lp_build_resize(gallivm, tmp_type, new_type, tmp, num_srcs, tmp, num_dsts);
tmp_type = new_type;
num_tmps = num_dsts;
}
/*
* Scale to the widest range
*/
if(src_type.floating) {
/* Nothing to do */
}
else if(!src_type.floating && dst_type.floating) {
if(!src_type.fixed && !src_type.sign && src_type.norm) {
for(i = 0; i < num_tmps; ++i) {
tmp[i] = lp_build_unsigned_norm_to_float(gallivm,
src_type.width,
dst_type,
tmp[i]);
}
tmp_type.floating = TRUE;
}
else {
double src_scale = lp_const_scale(src_type);
LLVMTypeRef tmp_vec_type;
/* Use an equally sized integer for intermediate computations */
tmp_type.floating = TRUE;
tmp_type.sign = TRUE;
tmp_vec_type = lp_build_vec_type(gallivm, tmp_type);
for(i = 0; i < num_tmps; ++i) {
#if 0
if(dst_type.sign)
tmp[i] = LLVMBuildSIToFP(builder, tmp[i], tmp_vec_type, "");
else
tmp[i] = LLVMBuildUIToFP(builder, tmp[i], tmp_vec_type, "");
#else
/* FIXME: there is no SSE counterpart for LLVMBuildUIToFP */
tmp[i] = LLVMBuildSIToFP(builder, tmp[i], tmp_vec_type, "");
#endif
}
if (src_scale != 1.0) {
LLVMValueRef scale = lp_build_const_vec(gallivm, tmp_type, 1.0/src_scale);
for(i = 0; i < num_tmps; ++i)
tmp[i] = LLVMBuildFMul(builder, tmp[i], scale, "");
}
/* the formula above will produce value below -1.0 for most negative
* value but everything seems happy with that hence disable for now */
if (0 && !src_type.fixed && src_type.norm && src_type.sign) {
struct lp_build_context bld;
lp_build_context_init(&bld, gallivm, dst_type);
for(i = 0; i < num_tmps; ++i) {
tmp[i] = lp_build_max(&bld, tmp[i],
lp_build_const_vec(gallivm, dst_type, -1.0f));
}
}
}
}
else {
unsigned src_shift = lp_const_shift(src_type);
unsigned dst_shift = lp_const_shift(dst_type);
unsigned src_offset = lp_const_offset(src_type);
unsigned dst_offset = lp_const_offset(dst_type);
struct lp_build_context bld;
lp_build_context_init(&bld, gallivm, tmp_type);
if (src_shift < dst_shift) {
LLVMValueRef pre_shift[LP_MAX_VECTOR_LENGTH];
if (dst_shift - src_shift < dst_type.width) {
for (i = 0; i < num_tmps; ++i) {
pre_shift[i] = tmp[i];
tmp[i] = lp_build_shl_imm(&bld, tmp[i], dst_shift - src_shift);
}
}
else {
/*
* This happens for things like sscaled -> unorm conversions. Shift
* counts equal to bit width cause undefined results, so hack around it.
*/
for (i = 0; i < num_tmps; ++i) {
pre_shift[i] = tmp[i];
tmp[i] = lp_build_zero(gallivm, dst_type);
}
}
/* Compensate for different offsets */
if (dst_offset > src_offset) {
for (i = 0; i < num_tmps; ++i) {
tmp[i] = LLVMBuildSub(builder, tmp[i], pre_shift[i], "");
}
}
}
}
for(i = 0; i < num_dsts; ++i) {
dst[i] = tmp[i];
assert(lp_check_value(dst_type, dst[i]));
}
}
/**
* Bit mask conversion.
*
* This will convert the integer masks that match the given types.
*
* The mask values should 0 or -1, i.e., all bits either set to zero or one.
* Any other value will likely cause unpredictable results.
*
* This is basically a very trimmed down version of lp_build_conv.
*/
void
lp_build_conv_mask(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type dst_type,
const LLVMValueRef *src, unsigned num_srcs,
LLVMValueRef *dst, unsigned num_dsts)
{
/* We must not loose or gain channels. Only precision */
assert(src_type.length * num_srcs == dst_type.length * num_dsts);
/*
* Drop
*
* We assume all values are 0 or -1
*/
src_type.floating = FALSE;
src_type.fixed = FALSE;
src_type.sign = TRUE;
src_type.norm = FALSE;
dst_type.floating = FALSE;
dst_type.fixed = FALSE;
dst_type.sign = TRUE;
dst_type.norm = FALSE;
/*
* Truncate or expand bit width
*/
lp_build_resize(gallivm, src_type, dst_type, src, num_srcs, dst, num_dsts);
}