[Mesa-dev] [PATCH v4 39/48] nir: Add a new subgroups lowering pass
Jason Ekstrand
jason at jlekstrand.net
Tue Oct 31 23:54:30 UTC 2017
This commit pulls nir_lower_read_invocations_to_scalar along with most
of the guts of nir_opt_intrinsics (which mostly does subgroup lowering)
into a new nir_lower_subgroups pass. There are various other bits of
subgroup lowering that we're going to want to do so it makes a bit more
sense to keep it all together in one pass. We also move it in i965 to
happen after nir_lower_system_values to ensure that because we want to
handle the subgroup mask system value intrinsics here.
Reviewed-by: Iago Toral Quiroga <itoral at igalia.com>
---
src/compiler/Makefile.sources | 2 +-
src/compiler/nir/meson.build | 2 +-
src/compiler/nir/nir.h | 12 +-
.../nir/nir_lower_read_invocation_to_scalar.c | 112 -------------
src/compiler/nir/nir_lower_subgroups.c | 184 +++++++++++++++++++++
src/compiler/nir/nir_opt_intrinsics.c | 71 +-------
src/intel/compiler/brw_compiler.c | 3 -
src/intel/compiler/brw_nir.c | 8 +-
8 files changed, 208 insertions(+), 186 deletions(-)
delete mode 100644 src/compiler/nir/nir_lower_read_invocation_to_scalar.c
create mode 100644 src/compiler/nir/nir_lower_subgroups.c
diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
index 27cc33a..12d932f 100644
--- a/src/compiler/Makefile.sources
+++ b/src/compiler/Makefile.sources
@@ -233,11 +233,11 @@ NIR_FILES = \
nir/nir_lower_passthrough_edgeflags.c \
nir/nir_lower_patch_vertices.c \
nir/nir_lower_phis_to_scalar.c \
- nir/nir_lower_read_invocation_to_scalar.c \
nir/nir_lower_regs_to_ssa.c \
nir/nir_lower_returns.c \
nir/nir_lower_samplers.c \
nir/nir_lower_samplers_as_deref.c \
+ nir/nir_lower_subgroups.c \
nir/nir_lower_system_values.c \
nir/nir_lower_tex.c \
nir/nir_lower_to_source_mods.c \
diff --git a/src/compiler/nir/meson.build b/src/compiler/nir/meson.build
index cb88eff..5c22bf6 100644
--- a/src/compiler/nir/meson.build
+++ b/src/compiler/nir/meson.build
@@ -120,11 +120,11 @@ files_libnir = files(
'nir_lower_passthrough_edgeflags.c',
'nir_lower_patch_vertices.c',
'nir_lower_phis_to_scalar.c',
- 'nir_lower_read_invocation_to_scalar.c',
'nir_lower_regs_to_ssa.c',
'nir_lower_returns.c',
'nir_lower_samplers.c',
'nir_lower_samplers_as_deref.c',
+ 'nir_lower_subgroups.c',
'nir_lower_system_values.c',
'nir_lower_tex.c',
'nir_lower_to_source_mods.c',
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index dd833cf..8c3a20c 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -1835,9 +1835,6 @@ typedef struct nir_shader_compiler_options {
bool lower_extract_byte;
bool lower_extract_word;
- bool lower_vote_trivial;
- bool lower_subgroup_masks;
-
/**
* Does the driver support real 32-bit integers? (Otherwise, integers
* are simulated by floats.)
@@ -2462,6 +2459,15 @@ bool nir_lower_samplers(nir_shader *shader,
bool nir_lower_samplers_as_deref(nir_shader *shader,
const struct gl_shader_program *shader_program);
+typedef struct nir_lower_subgroups_options {
+ bool lower_to_scalar:1;
+ bool lower_vote_trivial:1;
+ bool lower_subgroup_masks:1;
+} nir_lower_subgroups_options;
+
+bool nir_lower_subgroups(nir_shader *shader,
+ const nir_lower_subgroups_options *options);
+
bool nir_lower_system_values(nir_shader *shader);
typedef struct nir_lower_tex_options {
diff --git a/src/compiler/nir/nir_lower_read_invocation_to_scalar.c b/src/compiler/nir/nir_lower_read_invocation_to_scalar.c
deleted file mode 100644
index 69e7c0a..0000000
--- a/src/compiler/nir/nir_lower_read_invocation_to_scalar.c
+++ /dev/null
@@ -1,112 +0,0 @@
-/*
- * Copyright © 2017 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.
- */
-
-#include "nir.h"
-#include "nir_builder.h"
-
-/** @file nir_lower_read_invocation_to_scalar.c
- *
- * Replaces nir_intrinsic_read_invocation/nir_intrinsic_read_first_invocation
- * operations with num_components != 1 with individual per-channel operations.
- */
-
-static void
-lower_read_invocation_to_scalar(nir_builder *b, nir_intrinsic_instr *intrin)
-{
- b->cursor = nir_before_instr(&intrin->instr);
-
- nir_ssa_def *value = nir_ssa_for_src(b, intrin->src[0], intrin->num_components);
- nir_ssa_def *reads[4];
-
- for (unsigned i = 0; i < intrin->num_components; i++) {
- nir_intrinsic_instr *chan_intrin =
- nir_intrinsic_instr_create(b->shader, intrin->intrinsic);
- nir_ssa_dest_init(&chan_intrin->instr, &chan_intrin->dest,
- 1, intrin->dest.ssa.bit_size, NULL);
- chan_intrin->num_components = 1;
-
- /* value */
- chan_intrin->src[0] = nir_src_for_ssa(nir_channel(b, value, i));
- /* invocation */
- if (intrin->intrinsic == nir_intrinsic_read_invocation)
- nir_src_copy(&chan_intrin->src[1], &intrin->src[1], chan_intrin);
-
- nir_builder_instr_insert(b, &chan_intrin->instr);
-
- reads[i] = &chan_intrin->dest.ssa;
- }
-
- nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
- nir_src_for_ssa(nir_vec(b, reads,
- intrin->num_components)));
- nir_instr_remove(&intrin->instr);
-}
-
-static bool
-nir_lower_read_invocation_to_scalar_impl(nir_function_impl *impl)
-{
- bool progress = false;
- nir_builder b;
- nir_builder_init(&b, impl);
-
- nir_foreach_block(block, 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->num_components == 1)
- continue;
-
- switch (intrin->intrinsic) {
- case nir_intrinsic_read_invocation:
- case nir_intrinsic_read_first_invocation:
- lower_read_invocation_to_scalar(&b, intrin);
- progress = true;
- break;
- default:
- break;
- }
- }
- }
-
- if (progress) {
- nir_metadata_preserve(impl, nir_metadata_block_index |
- nir_metadata_dominance);
- }
- return progress;
-}
-
-bool
-nir_lower_read_invocation_to_scalar(nir_shader *shader)
-{
- bool progress = false;
-
- nir_foreach_function(function, shader) {
- if (function->impl)
- progress |= nir_lower_read_invocation_to_scalar_impl(function->impl);
- }
-
- return progress;
-}
diff --git a/src/compiler/nir/nir_lower_subgroups.c b/src/compiler/nir/nir_lower_subgroups.c
new file mode 100644
index 0000000..0d11dc9
--- /dev/null
+++ b/src/compiler/nir/nir_lower_subgroups.c
@@ -0,0 +1,184 @@
+/*
+ * Copyright © 2017 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.
+ */
+
+#include "nir.h"
+#include "nir_builder.h"
+
+/**
+ * \file nir_opt_intrinsics.c
+ */
+
+static nir_ssa_def *
+lower_read_invocation_to_scalar(nir_builder *b, nir_intrinsic_instr *intrin)
+{
+ /* This is safe to call on scalar things but it would be silly */
+ assert(intrin->dest.ssa.num_components > 1);
+
+ nir_ssa_def *value = nir_ssa_for_src(b, intrin->src[0],
+ intrin->num_components);
+ nir_ssa_def *reads[4];
+
+ for (unsigned i = 0; i < intrin->num_components; i++) {
+ nir_intrinsic_instr *chan_intrin =
+ nir_intrinsic_instr_create(b->shader, intrin->intrinsic);
+ nir_ssa_dest_init(&chan_intrin->instr, &chan_intrin->dest,
+ 1, intrin->dest.ssa.bit_size, NULL);
+ chan_intrin->num_components = 1;
+
+ /* value */
+ chan_intrin->src[0] = nir_src_for_ssa(nir_channel(b, value, i));
+ /* invocation */
+ if (intrin->intrinsic == nir_intrinsic_read_invocation)
+ nir_src_copy(&chan_intrin->src[1], &intrin->src[1], chan_intrin);
+
+ nir_builder_instr_insert(b, &chan_intrin->instr);
+
+ reads[i] = &chan_intrin->dest.ssa;
+ }
+
+ return nir_vec(b, reads, intrin->num_components);
+}
+
+static nir_ssa_def *
+high_subgroup_mask(nir_builder *b,
+ nir_ssa_def *count,
+ uint64_t base_mask)
+{
+ /* group_mask could probably be calculated more efficiently but we want to
+ * be sure not to shift by 64 if the subgroup size is 64 because the GLSL
+ * shift operator is undefined in that case. In any case if we were worried
+ * about efficency this should probably be done further down because the
+ * subgroup size is likely to be known at compile time.
+ */
+ nir_ssa_def *subgroup_size = nir_load_subgroup_size(b);
+ nir_ssa_def *all_bits = nir_imm_int64(b, ~0ull);
+ nir_ssa_def *shift = nir_isub(b, nir_imm_int(b, 64), subgroup_size);
+ nir_ssa_def *group_mask = nir_ushr(b, all_bits, shift);
+ nir_ssa_def *higher_bits = nir_ishl(b, nir_imm_int64(b, base_mask), count);
+
+ return nir_iand(b, higher_bits, group_mask);
+}
+
+static nir_ssa_def *
+lower_subgroups_intrin(nir_builder *b, nir_intrinsic_instr *intrin,
+ const nir_lower_subgroups_options *options)
+{
+ switch (intrin->intrinsic) {
+ case nir_intrinsic_vote_any:
+ case nir_intrinsic_vote_all:
+ if (options->lower_vote_trivial)
+ return nir_ssa_for_src(b, intrin->src[0], 1);
+ break;
+
+ case nir_intrinsic_vote_eq:
+ if (options->lower_vote_trivial)
+ return nir_imm_int(b, NIR_TRUE);
+ break;
+
+ case nir_intrinsic_read_invocation:
+ case nir_intrinsic_read_first_invocation:
+ if (options->lower_to_scalar && intrin->num_components > 1)
+ return lower_read_invocation_to_scalar(b, intrin);
+ break;
+
+ case nir_intrinsic_load_subgroup_eq_mask:
+ case nir_intrinsic_load_subgroup_ge_mask:
+ case nir_intrinsic_load_subgroup_gt_mask:
+ case nir_intrinsic_load_subgroup_le_mask:
+ case nir_intrinsic_load_subgroup_lt_mask: {
+ if (!options->lower_subgroup_masks)
+ return NULL;
+
+ nir_ssa_def *count = nir_load_subgroup_invocation(b);
+
+ switch (intrin->intrinsic) {
+ case nir_intrinsic_load_subgroup_eq_mask:
+ return nir_ishl(b, nir_imm_int64(b, 1ull), count);
+ case nir_intrinsic_load_subgroup_ge_mask:
+ return high_subgroup_mask(b, count, ~0ull);
+ case nir_intrinsic_load_subgroup_gt_mask:
+ return high_subgroup_mask(b, count, ~1ull);
+ case nir_intrinsic_load_subgroup_le_mask:
+ return nir_inot(b, nir_ishl(b, nir_imm_int64(b, ~1ull), count));
+ case nir_intrinsic_load_subgroup_lt_mask:
+ return nir_inot(b, nir_ishl(b, nir_imm_int64(b, ~0ull), count));
+ default:
+ unreachable("you seriously can't tell this is unreachable?");
+ }
+ break;
+ }
+ default:
+ break;
+ }
+
+ return NULL;
+}
+
+static bool
+lower_subgroups_impl(nir_function_impl *impl,
+ const nir_lower_subgroups_options *options)
+{
+ nir_builder b;
+ nir_builder_init(&b, impl);
+ bool progress = false;
+
+ nir_foreach_block(block, 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 = lower_subgroups_intrin(&b, intrin, options);
+ if (!lower)
+ continue;
+
+ nir_ssa_def_rewrite_uses(&intrin->dest.ssa, nir_src_for_ssa(lower));
+ nir_instr_remove(instr);
+ progress = true;
+ }
+ }
+
+ return progress;
+}
+
+bool
+nir_lower_subgroups(nir_shader *shader,
+ const nir_lower_subgroups_options *options)
+{
+ bool progress = false;
+
+ nir_foreach_function(function, shader) {
+ if (!function->impl)
+ continue;
+
+ if (lower_subgroups_impl(function->impl, options)) {
+ progress = true;
+ nir_metadata_preserve(function->impl, nir_metadata_block_index |
+ nir_metadata_dominance);
+ }
+ }
+
+ return progress;
+}
diff --git a/src/compiler/nir/nir_opt_intrinsics.c b/src/compiler/nir/nir_opt_intrinsics.c
index d5fdc51..98c8b1a 100644
--- a/src/compiler/nir/nir_opt_intrinsics.c
+++ b/src/compiler/nir/nir_opt_intrinsics.c
@@ -28,26 +28,6 @@
* \file nir_opt_intrinsics.c
*/
-static nir_ssa_def *
-high_subgroup_mask(nir_builder *b,
- nir_ssa_def *count,
- uint64_t base_mask)
-{
- /* group_mask could probably be calculated more efficiently but we want to
- * be sure not to shift by 64 if the subgroup size is 64 because the GLSL
- * shift operator is undefined in that case. In any case if we were worried
- * about efficency this should probably be done further down because the
- * subgroup size is likely to be known at compile time.
- */
- nir_ssa_def *subgroup_size = nir_load_subgroup_size(b);
- nir_ssa_def *all_bits = nir_imm_int64(b, ~0ull);
- nir_ssa_def *shift = nir_isub(b, nir_imm_int(b, 64), subgroup_size);
- nir_ssa_def *group_mask = nir_ushr(b, all_bits, shift);
- nir_ssa_def *higher_bits = nir_ishl(b, nir_imm_int64(b, base_mask), count);
-
- return nir_iand(b, higher_bits, group_mask);
-}
-
static bool
opt_intrinsics_impl(nir_function_impl *impl)
{
@@ -66,22 +46,14 @@ opt_intrinsics_impl(nir_function_impl *impl)
switch (intrin->intrinsic) {
case nir_intrinsic_vote_any:
- case nir_intrinsic_vote_all: {
- nir_const_value *val = nir_src_as_const_value(intrin->src[0]);
- if (!val && !b.shader->options->lower_vote_trivial)
- continue;
-
- replacement = nir_ssa_for_src(&b, intrin->src[0], 1);
+ case nir_intrinsic_vote_all:
+ if (nir_src_as_const_value(intrin->src[0]))
+ replacement = nir_ssa_for_src(&b, intrin->src[0], 1);
break;
- }
- case nir_intrinsic_vote_eq: {
- nir_const_value *val = nir_src_as_const_value(intrin->src[0]);
- if (!val && !b.shader->options->lower_vote_trivial)
- continue;
-
- replacement = nir_imm_int(&b, NIR_TRUE);
+ case nir_intrinsic_vote_eq:
+ if (nir_src_as_const_value(intrin->src[0]))
+ replacement = nir_imm_int(&b, NIR_TRUE);
break;
- }
case nir_intrinsic_ballot: {
assert(b.shader->options->max_subgroup_size != 0);
if (b.shader->options->max_subgroup_size > 32 ||
@@ -100,37 +72,6 @@ opt_intrinsics_impl(nir_function_impl *impl)
nir_imm_int(&b, 0));
break;
}
- case nir_intrinsic_load_subgroup_eq_mask:
- case nir_intrinsic_load_subgroup_ge_mask:
- case nir_intrinsic_load_subgroup_gt_mask:
- case nir_intrinsic_load_subgroup_le_mask:
- case nir_intrinsic_load_subgroup_lt_mask: {
- if (!b.shader->options->lower_subgroup_masks)
- break;
-
- nir_ssa_def *count = nir_load_subgroup_invocation(&b);
-
- switch (intrin->intrinsic) {
- case nir_intrinsic_load_subgroup_eq_mask:
- replacement = nir_ishl(&b, nir_imm_int64(&b, 1ull), count);
- break;
- case nir_intrinsic_load_subgroup_ge_mask:
- replacement = high_subgroup_mask(&b, count, ~0ull);
- break;
- case nir_intrinsic_load_subgroup_gt_mask:
- replacement = high_subgroup_mask(&b, count, ~1ull);
- break;
- case nir_intrinsic_load_subgroup_le_mask:
- replacement = nir_inot(&b, nir_ishl(&b, nir_imm_int64(&b, ~1ull), count));
- break;
- case nir_intrinsic_load_subgroup_lt_mask:
- replacement = nir_inot(&b, nir_ishl(&b, nir_imm_int64(&b, ~0ull), count));
- break;
- default:
- unreachable("you seriously can't tell this is unreachable?");
- }
- break;
- }
default:
break;
}
diff --git a/src/intel/compiler/brw_compiler.c b/src/intel/compiler/brw_compiler.c
index 2f6af7d..a6129e9 100644
--- a/src/intel/compiler/brw_compiler.c
+++ b/src/intel/compiler/brw_compiler.c
@@ -57,7 +57,6 @@ static const struct nir_shader_compiler_options scalar_nir_options = {
.lower_unpack_snorm_4x8 = true,
.lower_unpack_unorm_2x16 = true,
.lower_unpack_unorm_4x8 = true,
- .lower_subgroup_masks = true,
.max_subgroup_size = 32,
.max_unroll_iterations = 32,
};
@@ -80,7 +79,6 @@ static const struct nir_shader_compiler_options vector_nir_options = {
.lower_unpack_unorm_2x16 = true,
.lower_extract_byte = true,
.lower_extract_word = true,
- .lower_vote_trivial = true,
.max_unroll_iterations = 32,
};
@@ -99,7 +97,6 @@ static const struct nir_shader_compiler_options vector_nir_options_gen6 = {
.lower_unpack_unorm_2x16 = true,
.lower_extract_byte = true,
.lower_extract_word = true,
- .lower_vote_trivial = true,
.max_unroll_iterations = 32,
};
diff --git a/src/intel/compiler/brw_nir.c b/src/intel/compiler/brw_nir.c
index e5ff6de..f599f74 100644
--- a/src/intel/compiler/brw_nir.c
+++ b/src/intel/compiler/brw_nir.c
@@ -620,7 +620,6 @@ brw_preprocess_nir(const struct brw_compiler *compiler, nir_shader *nir)
OPT(nir_lower_tex, &tex_options);
OPT(nir_normalize_cubemap_coords);
- OPT(nir_lower_read_invocation_to_scalar);
OPT(nir_lower_global_vars_to_local);
@@ -637,6 +636,13 @@ brw_preprocess_nir(const struct brw_compiler *compiler, nir_shader *nir)
OPT(nir_lower_system_values);
+ const nir_lower_subgroups_options subgroups_options = {
+ .lower_to_scalar = true,
+ .lower_subgroup_masks = true,
+ .lower_vote_trivial = !is_scalar,
+ };
+ OPT(nir_lower_subgroups, &subgroups_options);
+
OPT(nir_lower_clip_cull_distance_arrays);
nir_variable_mode indirect_mask = 0;
--
2.5.0.400.gff86faf
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