Mesa (main): nir: Rename is_arb_asm to use_legacy_math_rules and document its meaning.
GitLab Mirror
gitlab-mirror at kemper.freedesktop.org
Fri Jun 10 03:54:57 UTC 2022
Module: Mesa
Branch: main
Commit: cf265c66066828a63641497086c8d29c004a99ed
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=cf265c66066828a63641497086c8d29c004a99ed
Author: Emma Anholt <emma at anholt.net>
Date: Tue Apr 26 11:58:14 2022 -0700
nir: Rename is_arb_asm to use_legacy_math_rules and document its meaning.
On iris and crocus, this flag is used to set "alt mode" math on the shader
as a whole. Some other drivers have a similar mode for DX9/ARB-program
behavior, so document what it does so we can start using it.
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16176>
---
src/compiler/glsl/standalone.cpp | 2 +-
src/compiler/shader_info.h | 23 +++++++++++++++++++++--
src/gallium/drivers/crocus/crocus_program.c | 4 ++--
src/gallium/drivers/iris/iris_program.c | 4 ++--
src/gallium/drivers/radeonsi/si_shader_nir.c | 2 +-
src/mesa/main/uniform_query.cpp | 4 ++--
src/mesa/program/program.c | 2 +-
7 files changed, 30 insertions(+), 11 deletions(-)
diff --git a/src/compiler/glsl/standalone.cpp b/src/compiler/glsl/standalone.cpp
index d79151c1f56..b94ded29dfe 100644
--- a/src/compiler/glsl/standalone.cpp
+++ b/src/compiler/glsl/standalone.cpp
@@ -102,7 +102,7 @@ init_gl_program(struct gl_program *prog, bool is_arb_asm, gl_shader_stage stage)
{
prog->RefCount = 1;
prog->Format = GL_PROGRAM_FORMAT_ASCII_ARB;
- prog->info.is_arb_asm = is_arb_asm;
+ prog->info.use_legacy_math_rules = is_arb_asm;
prog->info.stage = stage;
}
diff --git a/src/compiler/shader_info.h b/src/compiler/shader_info.h
index 186cef2619c..86d7ca14505 100644
--- a/src/compiler/shader_info.h
+++ b/src/compiler/shader_info.h
@@ -310,9 +310,28 @@ typedef struct shader_info {
bool workgroup_size_variable:1;
/**
- * Is this an ARB assembly-style program.
+ * Set if this shader uses legacy (DX9 or ARB assembly) math rules.
+ *
+ * From the ARB_fragment_program specification:
+ *
+ * "The following rules apply to multiplication:
+ *
+ * 1. <x> * <y> == <y> * <x>, for all <x> and <y>.
+ * 2. +/-0.0 * <x> = +/-0.0, at least for all <x> that correspond to
+ * *representable numbers (IEEE "not a number" and "infinity"
+ * *encodings may be exceptions).
+ * 3. +1.0 * <x> = <x>, for all <x>.""
+ *
+ * However, in effect this was due to DX9 semantics implying that 0*x=0 even
+ * for inf/nan if the hardware generated them instead of float_min/max. So,
+ * you should not have an exception for inf/nan to rule 2 above.
+ *
+ * One implementation of this behavior would be to flush all generated NaNs
+ * to zero, at which point 0*Inf=Nan=0. Most DX9/ARB-asm hardware did not
+ * generate NaNs, and the only way the GPU saw one was to possibly feed it
+ * in as a uniform.
*/
- bool is_arb_asm;
+ bool use_legacy_math_rules;
union {
struct {
diff --git a/src/gallium/drivers/crocus/crocus_program.c b/src/gallium/drivers/crocus/crocus_program.c
index f1ee9b9c816..b07a4ceb20f 100644
--- a/src/gallium/drivers/crocus/crocus_program.c
+++ b/src/gallium/drivers/crocus/crocus_program.c
@@ -1208,7 +1208,7 @@ crocus_compile_vs(struct crocus_context *ice,
if (key->clamp_pointsize)
nir_lower_point_size(nir, 1.0, 255.0);
- prog_data->use_alt_mode = nir->info.is_arb_asm;
+ prog_data->use_alt_mode = nir->info.use_legacy_math_rules;
crocus_setup_uniforms(compiler, mem_ctx, nir, prog_data, &system_values,
&num_system_values, &num_cbufs);
@@ -1858,7 +1858,7 @@ crocus_compile_fs(struct crocus_context *ice,
nir_shader *nir = nir_shader_clone(mem_ctx, ish->nir);
- prog_data->use_alt_mode = nir->info.is_arb_asm;
+ prog_data->use_alt_mode = nir->info.use_legacy_math_rules;
crocus_setup_uniforms(compiler, mem_ctx, nir, prog_data, &system_values,
&num_system_values, &num_cbufs);
diff --git a/src/gallium/drivers/iris/iris_program.c b/src/gallium/drivers/iris/iris_program.c
index 02423c0d308..64097d87de2 100644
--- a/src/gallium/drivers/iris/iris_program.c
+++ b/src/gallium/drivers/iris/iris_program.c
@@ -1335,7 +1335,7 @@ iris_compile_vs(struct iris_screen *screen,
nir_shader_gather_info(nir, impl);
}
- prog_data->use_alt_mode = nir->info.is_arb_asm;
+ prog_data->use_alt_mode = nir->info.use_legacy_math_rules;
iris_setup_uniforms(compiler, mem_ctx, nir, prog_data, 0, &system_values,
&num_system_values, &num_cbufs);
@@ -1967,7 +1967,7 @@ iris_compile_fs(struct iris_screen *screen,
nir_shader *nir = nir_shader_clone(mem_ctx, ish->nir);
const struct iris_fs_prog_key *const key = &shader->key.fs;
- prog_data->use_alt_mode = nir->info.is_arb_asm;
+ prog_data->use_alt_mode = nir->info.use_legacy_math_rules;
iris_setup_uniforms(compiler, mem_ctx, nir, prog_data, 0, &system_values,
&num_system_values, &num_cbufs);
diff --git a/src/gallium/drivers/radeonsi/si_shader_nir.c b/src/gallium/drivers/radeonsi/si_shader_nir.c
index ec1013f8d74..0c64689ccef 100644
--- a/src/gallium/drivers/radeonsi/si_shader_nir.c
+++ b/src/gallium/drivers/radeonsi/si_shader_nir.c
@@ -273,7 +273,7 @@ static void si_lower_nir(struct si_screen *sscreen, struct nir_shader *nir)
NIR_PASS_V(nir, nir_lower_discard_or_demote,
(sscreen->debug_flags & DBG(FS_CORRECT_DERIVS_AFTER_KILL)) ||
- nir->info.is_arb_asm);
+ nir->info.use_legacy_math_rules);
/* Lower load constants to scalar and then clean up the mess */
NIR_PASS_V(nir, nir_lower_load_const_to_scalar);
diff --git a/src/mesa/main/uniform_query.cpp b/src/mesa/main/uniform_query.cpp
index 86e25c8861d..6135c80586a 100644
--- a/src/mesa/main/uniform_query.cpp
+++ b/src/mesa/main/uniform_query.cpp
@@ -956,7 +956,7 @@ associate_uniform_storage(struct gl_context *ctx,
unsigned columns = 0;
int dmul;
- if (ctx->Const.PackedDriverUniformStorage && !prog->info.is_arb_asm) {
+ if (ctx->Const.PackedDriverUniformStorage && !prog->info.use_legacy_math_rules) {
dmul = storage->type->vector_elements * sizeof(float);
} else {
dmul = 4 * sizeof(float);
@@ -1050,7 +1050,7 @@ associate_uniform_storage(struct gl_context *ctx,
* initializers in the source code to be copied over.
*/
unsigned array_elements = MAX2(1, storage->array_elements);
- if (ctx->Const.PackedDriverUniformStorage && !prog->info.is_arb_asm &&
+ if (ctx->Const.PackedDriverUniformStorage && !prog->info.use_legacy_math_rules &&
(storage->is_bindless || !storage->type->contains_opaque())) {
const int dmul = storage->type->is_64bit() ? 2 : 1;
const unsigned components =
diff --git a/src/mesa/program/program.c b/src/mesa/program/program.c
index 1cf8ae48004..c151b92ee50 100644
--- a/src/mesa/program/program.c
+++ b/src/mesa/program/program.c
@@ -196,7 +196,7 @@ _mesa_init_gl_program(struct gl_program *prog, gl_shader_stage stage,
prog->RefCount = 1;
prog->Format = GL_PROGRAM_FORMAT_ASCII_ARB;
prog->info.stage = stage;
- prog->info.is_arb_asm = is_arb_asm;
+ prog->info.use_legacy_math_rules = is_arb_asm;
/* Uniforms that lack an initializer in the shader code have an initial
* value of zero. This includes sampler uniforms.
More information about the mesa-commit
mailing list