bc6b527b52
We need to use nir_is_helper_invocation instead of
nir_load_helper_invocation, to correctly predicate stores after demote.
Identified in a Piglit on AGX a year ago but I forgot to upstream this.
Fixes: 586da7b329 ("nir: Add nir_lower_helper_writes pass")
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Mary Guillemard <mary.guillemard@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33939>
112 lines
4.0 KiB
C
112 lines
4.0 KiB
C
/*
|
|
* Copyright (C) 2020-2021 Collabora, Ltd.
|
|
* Copyright © 2020 Valve 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.
|
|
*/
|
|
|
|
#include "compiler/nir/nir.h"
|
|
#include "compiler/nir/nir_builder.h"
|
|
|
|
static bool
|
|
lower(nir_builder *b, nir_intrinsic_instr *intr, void *data)
|
|
{
|
|
bool *lower_plain_stores = data;
|
|
|
|
switch (intr->intrinsic) {
|
|
case nir_intrinsic_global_atomic:
|
|
case nir_intrinsic_global_atomic_swap:
|
|
case nir_intrinsic_image_atomic:
|
|
case nir_intrinsic_image_atomic_swap:
|
|
case nir_intrinsic_bindless_image_atomic:
|
|
case nir_intrinsic_bindless_image_atomic_swap:
|
|
break;
|
|
case nir_intrinsic_store_global:
|
|
case nir_intrinsic_image_store:
|
|
case nir_intrinsic_bindless_image_store:
|
|
if (!(*lower_plain_stores))
|
|
return false;
|
|
else
|
|
break;
|
|
default:
|
|
return false;
|
|
}
|
|
|
|
b->cursor = nir_before_instr(&intr->instr);
|
|
bool has_dest = nir_intrinsic_infos[intr->intrinsic].has_dest;
|
|
nir_def *undef = NULL;
|
|
|
|
/* We need to use nir_is_helper_invocation instead of
|
|
* nir_load_helper_invocation, to correctly predicate stores after demote.
|
|
*/
|
|
nir_def *helper = nir_is_helper_invocation(b, 1);
|
|
nir_push_if(b, nir_inot(b, helper));
|
|
nir_instr_remove(&intr->instr);
|
|
nir_builder_instr_insert(b, &intr->instr);
|
|
|
|
/* Per the spec, it does not matter what we return for helper threads.
|
|
* Represent this by an ssa_undef in the hopes the backend will be clever
|
|
* enough to optimize out the phi.
|
|
*
|
|
* Fragment shader helper invocations execute the same shader code as
|
|
* non-helper invocations, but will not have side effects that modify the
|
|
* framebuffer or other shader-accessible memory. In particular:
|
|
*
|
|
* ...
|
|
*
|
|
* Atomic operations to image, buffer, or atomic counter variables
|
|
* performed by helper invocations have no effect on the underlying
|
|
* image or buffer memory. The values returned by such atomic
|
|
* operations are undefined.
|
|
*/
|
|
if (has_dest) {
|
|
nir_push_else(b, NULL);
|
|
undef = nir_undef(b, intr->def.num_components,
|
|
intr->def.bit_size);
|
|
}
|
|
|
|
nir_pop_if(b, NULL);
|
|
|
|
if (has_dest) {
|
|
nir_def *phi = nir_if_phi(b, &intr->def, undef);
|
|
|
|
/* We can't use nir_def_rewrite_uses_after on phis, so use the global
|
|
* version and fixup the phi manually
|
|
*/
|
|
nir_def_rewrite_uses(&intr->def, phi);
|
|
|
|
nir_instr *phi_instr = phi->parent_instr;
|
|
nir_phi_instr *phi_as_phi = nir_instr_as_phi(phi_instr);
|
|
nir_phi_src *phi_src = nir_phi_get_src_from_block(phi_as_phi,
|
|
intr->instr.block);
|
|
nir_src_rewrite(&phi_src->src, &intr->def);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool
|
|
nir_lower_helper_writes(nir_shader *shader, bool lower_plain_stores)
|
|
{
|
|
assert(shader->info.stage == MESA_SHADER_FRAGMENT);
|
|
return nir_shader_intrinsics_pass(shader, lower, nir_metadata_none,
|
|
&lower_plain_stores);
|
|
}
|