[Mesa-dev] [PATCH 03/16] ac/nir: Add vote_ieq/vote_feq lowering pass.
Timothy Arceri
tarceri at itsqueeze.com
Sat Mar 10 09:55:15 UTC 2018
This causes radeonsi to segfault on the piglit testss e.g.
R600_DEBUG=nir /bin/shader_runner
tests/spec/arb_shader_group_vote/cs-eq.shader_test -auto -fbo
On 08/03/18 01:47, Bas Nieuwenhuizen wrote:
> The old vote_eq implementation supported only booleans, but now
> we have to support arbitrary values, so use the read_first_invocation
> intrinsic + ballot.
>
> I took this as an opportunity to figure out how easy it was to do this
> in nir instead of in the nir_to_llvm pass, and it actually turned out
> pretty okay IMO. Only creating the pass is some extra code.
>
> Reviewed-by: Dave Airlie <airlied at redhat.com>
> ---
> src/amd/Makefile.sources | 1 +
> src/amd/common/ac_lower_subgroups.c | 92 +++++++++++++++++++++++++++++++++++++
> src/amd/common/ac_nir_to_llvm.c | 8 ++--
> src/amd/common/ac_nir_to_llvm.h | 2 +
> src/amd/common/meson.build | 1 +
> 5 files changed, 99 insertions(+), 5 deletions(-)
> create mode 100644 src/amd/common/ac_lower_subgroups.c
>
> diff --git a/src/amd/Makefile.sources b/src/amd/Makefile.sources
> index 10c4827e19..f57dd403c5 100644
> --- a/src/amd/Makefile.sources
> +++ b/src/amd/Makefile.sources
> @@ -44,6 +44,7 @@ AMD_COMPILER_FILES = \
> common/ac_llvm_helper.cpp \
> common/ac_llvm_util.c \
> common/ac_llvm_util.h \
> + common/ac_lower_subgroups.c \
> common/ac_shader_abi.h \
> common/ac_shader_info.c \
> common/ac_shader_info.h \
> diff --git a/src/amd/common/ac_lower_subgroups.c b/src/amd/common/ac_lower_subgroups.c
> new file mode 100644
> index 0000000000..d0782b481b
> --- /dev/null
> +++ b/src/amd/common/ac_lower_subgroups.c
> @@ -0,0 +1,92 @@
> +/*
> + * Copyright © 2018 Google Inc.
> + *
> + * 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 "nir/nir.h"
> +#include "nir/nir_builder.h"
> +
> +#include "ac_nir_to_llvm.h"
> +
> +static nir_ssa_def *ac_lower_subgroups_intrin(nir_builder *b, nir_intrinsic_instr *intrin)
> +{
> + switch(intrin->intrinsic) {
> + case nir_intrinsic_vote_ieq:
> + case nir_intrinsic_vote_feq: {
> + nir_intrinsic_instr *rfi =
> + nir_intrinsic_instr_create(b->shader, nir_intrinsic_read_first_invocation);
> + nir_ssa_dest_init(&rfi->instr, &rfi->dest,
> + 1, intrin->src[0].ssa->bit_size, NULL);
> + nir_src_copy(&rfi->src[0], &intrin->src[0], rfi);
> + rfi->num_components = 1;
> +
> + nir_ssa_def *is_ne;
> + if (intrin->intrinsic == nir_intrinsic_vote_feq)
> + is_ne = nir_fne(b, &rfi->dest.ssa, intrin->src[0].ssa);
> + else
> + is_ne = nir_ine(b, &rfi->dest.ssa, intrin->src[0].ssa);
> +
> + nir_intrinsic_instr *ballot =
> + nir_intrinsic_instr_create(b->shader, nir_intrinsic_ballot);
> + nir_ssa_dest_init(&ballot->instr, &ballot->dest,
> + 1, 64, NULL);
> + ballot->src[0] = nir_src_for_ssa(is_ne);
> + ballot->num_components = 1;
> +
> + return nir_ieq(b, &ballot->dest.ssa, nir_imm_int64(b, 0));
> + }
> + default:
> + return NULL;
> + }
> +}
> +
> +bool ac_lower_subgroups(struct nir_shader *shader)
> +{
> + bool progress = false;
> +
> + nir_foreach_function(function, shader) {
> + if (!function->impl)
> + continue;
> +
> + nir_builder b;
> + nir_builder_init(&b, function->impl);
> +
> + nir_foreach_block(block, function->impl) {
> + nir_foreach_instr_safe(instr, block) {
> + if (instr->type != nir_instr_type_intrinsic)
> + continue;
> +
> + nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
> + b.cursor = nir_before_instr(instr);
> +
> + nir_ssa_def *lower = ac_lower_subgroups_intrin(&b, intrin);
> + if (!lower)
> + continue;
> +
> + nir_ssa_def_rewrite_uses(&intrin->dest.ssa, nir_src_for_ssa(lower));
> + nir_instr_remove(instr);
> + progress = true;
> + }
> + }
> + }
> +
> + return progress;
> +}
> diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
> index d2df2837c8..3bf1a4ba3c 100644
> --- a/src/amd/common/ac_nir_to_llvm.c
> +++ b/src/amd/common/ac_nir_to_llvm.c
> @@ -4563,11 +4563,6 @@ static void visit_intrinsic(struct ac_nir_context *ctx,
> result = LLVMBuildSExt(ctx->ac.builder, tmp, ctx->ac.i32, "");
> break;
> }
> - case nir_intrinsic_vote_eq: {
> - LLVMValueRef tmp = ac_build_vote_eq(&ctx->ac, get_src(ctx, instr->src[0]));
> - result = LLVMBuildSExt(ctx->ac.builder, tmp, ctx->ac.i32, "");
> - break;
> - }
> default:
> fprintf(stderr, "Unknown intrinsic: ");
> nir_print_instr(&instr->instr, stderr);
> @@ -6737,6 +6732,9 @@ void ac_nir_translate(struct ac_llvm_context *ac, struct ac_shader_abi *abi,
> struct ac_nir_context ctx = {};
> struct nir_function *func;
>
> + /* Last minute passes for both radv & radeonsi */
> + ac_lower_subgroups(nir);
> +
> ctx.ac = *ac;
> ctx.abi = abi;
>
> diff --git a/src/amd/common/ac_nir_to_llvm.h b/src/amd/common/ac_nir_to_llvm.h
> index eea393a9c2..306039aecf 100644
> --- a/src/amd/common/ac_nir_to_llvm.h
> +++ b/src/amd/common/ac_nir_to_llvm.h
> @@ -234,4 +234,6 @@ void ac_lower_indirect_derefs(struct nir_shader *nir, enum chip_class);
> void ac_nir_translate(struct ac_llvm_context *ac, struct ac_shader_abi *abi,
> struct nir_shader *nir);
>
> +bool ac_lower_subgroups(struct nir_shader *shader);
> +
> #endif /* AC_NIR_TO_LLVM_H */
> diff --git a/src/amd/common/meson.build b/src/amd/common/meson.build
> index 22c13b955f..6c5c2f45ac 100644
> --- a/src/amd/common/meson.build
> +++ b/src/amd/common/meson.build
> @@ -35,6 +35,7 @@ amd_common_files = files(
> 'ac_llvm_helper.cpp',
> 'ac_llvm_util.c',
> 'ac_llvm_util.h',
> + 'ac_lower_subgroups.c',
> 'ac_shader_abi.h',
> 'ac_shader_info.c',
> 'ac_shader_info.h',
>
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