/*
* Copyright © 2017 Red Hat
*
* 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.
*
* Authors:
* Rob Clark <robclark@freedesktop.org>
*/
#include "nir.h"
#include "nir_builder.h"
#if defined(_WIN32) && !defined(snprintf)
#define snprintf _snprintf
#endif
/*
* Remap atomic counters to SSBOs. Atomic counters get remapped to
* SSBO binding points [0..ssbo_offset) and the original SSBOs are
* remapped to [ssbo_offset..n) (mostly to align with what mesa/st
* does.
*/
static bool
lower_instr(nir_intrinsic_instr *instr, unsigned ssbo_offset, nir_builder *b)
{
nir_intrinsic_op op;
int idx_src;
b->cursor = nir_before_instr(&instr->instr);
switch (instr->intrinsic) {
case nir_intrinsic_ssbo_atomic_add:
case nir_intrinsic_ssbo_atomic_imin:
case nir_intrinsic_ssbo_atomic_umin:
case nir_intrinsic_ssbo_atomic_imax:
case nir_intrinsic_ssbo_atomic_umax:
case nir_intrinsic_ssbo_atomic_and:
case nir_intrinsic_ssbo_atomic_or:
case nir_intrinsic_ssbo_atomic_xor:
case nir_intrinsic_ssbo_atomic_exchange:
case nir_intrinsic_ssbo_atomic_comp_swap:
case nir_intrinsic_store_ssbo:
case nir_intrinsic_load_ssbo:
case nir_intrinsic_get_buffer_size:
/* easy case, keep same opcode and just remap SSBO buffer index: */
op = instr->intrinsic;
idx_src = (op == nir_intrinsic_store_ssbo) ? 1 : 0;
nir_ssa_def *old_idx = nir_ssa_for_src(b, instr->src[idx_src], 1);
nir_ssa_def *new_idx = nir_iadd(b, old_idx, nir_imm_int(b, ssbo_offset));
nir_instr_rewrite_src(&instr->instr,
&instr->src[idx_src],
nir_src_for_ssa(new_idx));
return true;
case nir_intrinsic_atomic_counter_inc:
case nir_intrinsic_atomic_counter_add:
case nir_intrinsic_atomic_counter_dec:
/* inc and dec get remapped to add: */
op = nir_intrinsic_ssbo_atomic_add;
break;
case nir_intrinsic_atomic_counter_read:
op = nir_intrinsic_load_ssbo;
break;
case nir_intrinsic_atomic_counter_min:
op = nir_intrinsic_ssbo_atomic_umin;
break;
case nir_intrinsic_atomic_counter_max:
op = nir_intrinsic_ssbo_atomic_umax;
break;
case nir_intrinsic_atomic_counter_and:
op = nir_intrinsic_ssbo_atomic_and;
break;
case nir_intrinsic_atomic_counter_or:
op = nir_intrinsic_ssbo_atomic_or;
break;
case nir_intrinsic_atomic_counter_xor:
op = nir_intrinsic_ssbo_atomic_xor;
break;
case nir_intrinsic_atomic_counter_exchange:
op = nir_intrinsic_ssbo_atomic_exchange;
break;
case nir_intrinsic_atomic_counter_comp_swap:
op = nir_intrinsic_ssbo_atomic_comp_swap;
break;
default:
return false;
}
nir_ssa_def *buffer = nir_imm_int(b, nir_intrinsic_base(instr));
nir_ssa_def *temp = NULL;
nir_intrinsic_instr *new_instr =
nir_intrinsic_instr_create(ralloc_parent(instr), op);
/* a couple instructions need special handling since they don't map
* 1:1 with ssbo atomics
*/
switch (instr->intrinsic) {
case nir_intrinsic_atomic_counter_inc:
/* remapped to ssbo_atomic_add: { buffer_idx, offset, +1 } */
temp = nir_imm_int(b, +1);
new_instr->src[0] = nir_src_for_ssa(buffer);
nir_src_copy(&new_instr->src[1], &instr->src[0], new_instr);
new_instr->src[2] = nir_src_for_ssa(temp);
break;
case nir_intrinsic_atomic_counter_dec:
/* remapped to ssbo_atomic_add: { buffer_idx, offset, -1 } */
/* NOTE semantic difference so we adjust the return value below */
temp = nir_imm_int(b, -1);
new_instr->src[0] = nir_src_for_ssa(buffer);
nir_src_copy(&new_instr->src[1], &instr->src[0], new_instr);
new_instr->src[2] = nir_src_for_ssa(temp);
break;
case nir_intrinsic_atomic_counter_read:
/* remapped to load_ssbo: { buffer_idx, offset } */
new_instr->src[0] = nir_src_for_ssa(buffer);
nir_src_copy(&new_instr->src[1], &instr->src[0], new_instr);
break;
default:
/* remapped to ssbo_atomic_x: { buffer_idx, offset, data, (compare)? } */
new_instr->src[0] = nir_src_for_ssa(buffer);
nir_src_copy(&new_instr->src[1], &instr->src[0], new_instr);
nir_src_copy(&new_instr->src[2], &instr->src[1], new_instr);
if (op == nir_intrinsic_ssbo_atomic_comp_swap)
nir_src_copy(&new_instr->src[3], &instr->src[2], new_instr);
break;
}
nir_ssa_dest_init(&new_instr->instr, &new_instr->dest,
instr->dest.ssa.num_components,
instr->dest.ssa.bit_size, NULL);
nir_instr_insert_before(&instr->instr, &new_instr->instr);
nir_instr_remove(&instr->instr);
if (instr->intrinsic == nir_intrinsic_atomic_counter_dec) {
b->cursor = nir_after_instr(&new_instr->instr);
nir_ssa_def *result = nir_iadd(b, &new_instr->dest.ssa, temp);
nir_ssa_def_rewrite_uses(&instr->dest.ssa, nir_src_for_ssa(result));
} else {
nir_ssa_def_rewrite_uses(&instr->dest.ssa, nir_src_for_ssa(&new_instr->dest.ssa));
}
/* we could be replacing an intrinsic with fixed # of dest num_components
* with one that has variable number. So best to take this from the dest:
*/
new_instr->num_components = instr->dest.ssa.num_components;
return true;
}
static bool
is_atomic_uint(const struct glsl_type *type)
{
if (glsl_get_base_type(type) == GLSL_TYPE_ARRAY)
return is_atomic_uint(glsl_get_array_element(type));
return glsl_get_base_type(type) == GLSL_TYPE_ATOMIC_UINT;
}
bool
nir_lower_atomics_to_ssbo(nir_shader *shader, unsigned ssbo_offset)
{
bool progress = false;
nir_foreach_function(function, shader) {
if (function->impl) {
nir_builder builder;
nir_builder_init(&builder, function->impl);
nir_foreach_block(block, function->impl) {
nir_foreach_instr_safe(instr, block) {
if (instr->type == nir_instr_type_intrinsic)
progress |= lower_instr(nir_instr_as_intrinsic(instr),
ssbo_offset, &builder);
}
}
nir_metadata_preserve(function->impl, nir_metadata_block_index |
nir_metadata_dominance);
}
}
if (progress) {
/* replace atomic_uint uniforms with ssbo's: */
unsigned replaced = 0;
nir_foreach_variable_safe(var, &shader->uniforms) {
if (is_atomic_uint(var->type)) {
exec_node_remove(&var->node);
if (replaced & (1 << var->data.binding))
continue;
nir_variable *ssbo;
char name[16];
/* A length of 0 is used to denote unsized arrays */
const struct glsl_type *type = glsl_array_type(glsl_uint_type(), 0);
snprintf(name, sizeof(name), "counter%d", var->data.binding);
ssbo = nir_variable_create(shader, nir_var_shader_storage,
type, name);
ssbo->data.binding = var->data.binding;
struct glsl_struct_field field = {
.type = type,
.name = "counters",
.location = -1,
};
ssbo->interface_type =
glsl_interface_type(&field, 1, GLSL_INTERFACE_PACKING_STD430,
false, "counters");
replaced |= (1 << var->data.binding);
}
}
}
return progress;
}