[Mesa-dev] [PATCH 1/2] glsl: add driconf to zero-init unintialized vars
Rob Clark
robdclark at gmail.com
Sat Jun 25 12:37:47 UTC 2016
From: Rob Clark <robclark at freedesktop.org>
Some games are sloppy.. perhaps because it is defined behavior for DX or
perhaps because nv blob driver defaults things to zero.
So add driconf param to force uninitialized variables to default to zero.
This issue was observed with rust, from steam store. But has surfaced
elsewhere in the past.
Signed-off-by: Rob Clark <robclark at freedesktop.org>
---
Note that I left out the drirc bit, since not entirely sure how to
identify this game. (I don't actually have the game, just working off
of an apitrace)
Possibly worth mentioning that for the shaders using uninitialized vars
having zero-initializers lets constant-propagation get rid of a whole
lot of instructions. One shader I saw dropped to less than half of
it's original instruction count.
Second patch in the series is just fixing an i965 bug that was exposed
by this patch.
src/compiler/glsl/ast_to_hir.cpp | 9 +++++++++
src/compiler/glsl/glsl_parser_extras.cpp | 1 +
src/compiler/glsl/glsl_parser_extras.h | 1 +
src/gallium/include/state_tracker/st_api.h | 1 +
src/gallium/state_trackers/dri/dri_screen.c | 2 ++
src/mesa/drivers/dri/common/xmlpool/t_options.h | 5 ++++-
src/mesa/drivers/dri/i965/brw_context.c | 2 ++
src/mesa/drivers/dri/i965/intel_screen.c | 4 ++++
src/mesa/main/mtypes.h | 5 +++++
src/mesa/state_tracker/st_extensions.c | 2 ++
10 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
index 0cfce68..d2c284f 100644
--- a/src/compiler/glsl/ast_to_hir.cpp
+++ b/src/compiler/glsl/ast_to_hir.cpp
@@ -4697,6 +4697,15 @@ ast_declarator_list::hir(exec_list *instructions,
apply_layout_qualifier_to_variable(&this->type->qualifier, var, state,
&loc);
+ if ((var->data.mode == ir_var_auto || var->data.mode == ir_var_temporary)
+ && (var->type->base_type >= GLSL_TYPE_UINT)
+ && (var->type->base_type <= GLSL_TYPE_BOOL)
+ && state->zero_init) {
+ const ir_constant_data data = {0};
+ var->data.has_initializer = true;
+ var->constant_initializer = new(var) ir_constant(var->type, &data);
+ }
+
if (this->type->qualifier.flags.q.invariant) {
if (!is_varying_var(var, state->stage)) {
_mesa_glsl_error(&loc, state,
diff --git a/src/compiler/glsl/glsl_parser_extras.cpp b/src/compiler/glsl/glsl_parser_extras.cpp
index 09f7477..fc2859a 100644
--- a/src/compiler/glsl/glsl_parser_extras.cpp
+++ b/src/compiler/glsl/glsl_parser_extras.cpp
@@ -74,6 +74,7 @@ _mesa_glsl_parse_state::_mesa_glsl_parse_state(struct gl_context *_ctx,
/* Set default language version and extensions */
this->language_version = 110;
this->forced_language_version = ctx->Const.ForceGLSLVersion;
+ this->zero_init = ctx->Const.GLSLZeroInit;
this->es_shader = false;
this->ARB_texture_rectangle_enable = true;
diff --git a/src/compiler/glsl/glsl_parser_extras.h b/src/compiler/glsl/glsl_parser_extras.h
index 8c43292..669b3d1 100644
--- a/src/compiler/glsl/glsl_parser_extras.h
+++ b/src/compiler/glsl/glsl_parser_extras.h
@@ -306,6 +306,7 @@ struct _mesa_glsl_parse_state {
bool es_shader;
unsigned language_version;
unsigned forced_language_version;
+ bool zero_init;
gl_shader_stage stage;
/**
diff --git a/src/gallium/include/state_tracker/st_api.h b/src/gallium/include/state_tracker/st_api.h
index 41daa47..21d5177 100644
--- a/src/gallium/include/state_tracker/st_api.h
+++ b/src/gallium/include/state_tracker/st_api.h
@@ -242,6 +242,7 @@ struct st_config_options
unsigned force_glsl_version;
boolean force_s3tc_enable;
boolean allow_glsl_extension_directive_midshader;
+ boolean glsl_zero_init;
};
/**
diff --git a/src/gallium/state_trackers/dri/dri_screen.c b/src/gallium/state_trackers/dri/dri_screen.c
index 2ac55c8..b16585a 100644
--- a/src/gallium/state_trackers/dri/dri_screen.c
+++ b/src/gallium/state_trackers/dri/dri_screen.c
@@ -74,6 +74,7 @@ const __DRIconfigOptionsExtension gallium_config_options = {
DRI_CONF_SECTION_MISCELLANEOUS
DRI_CONF_ALWAYS_HAVE_DEPTH_BUFFER("false")
+ DRI_CONF_GLSL_ZERO_INIT("false")
DRI_CONF_SECTION_END
DRI_CONF_END
};
@@ -98,6 +99,7 @@ dri_fill_st_options(struct st_config_options *options,
driQueryOptionb(optionCache, "force_s3tc_enable");
options->allow_glsl_extension_directive_midshader =
driQueryOptionb(optionCache, "allow_glsl_extension_directive_midshader");
+ options->glsl_zero_init = driQueryOptionb(optionCache, "glsl_zero_init");
}
static const __DRIconfig **
diff --git a/src/mesa/drivers/dri/common/xmlpool/t_options.h b/src/mesa/drivers/dri/common/xmlpool/t_options.h
index 4b298a4..341c376 100644
--- a/src/mesa/drivers/dri/common/xmlpool/t_options.h
+++ b/src/mesa/drivers/dri/common/xmlpool/t_options.h
@@ -337,7 +337,10 @@ DRI_CONF_OPT_BEGIN_B(always_have_depth_buffer, def) \
DRI_CONF_DESC(en,gettext("Create all visuals with a depth buffer")) \
DRI_CONF_OPT_END
-
+#define DRI_CONF_GLSL_ZERO_INIT(def) \
+DRI_CONF_OPT_BEGIN_B(glsl_zero_init, def) \
+ DRI_CONF_DESC(en,gettext("Force uninitialized variables to default to zero")) \
+DRI_CONF_OPT_END
/**
* \brief Initialization configuration options
diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index c7a66cb..66d4e94 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -826,6 +826,8 @@ brw_process_driconf_options(struct brw_context *brw)
ctx->Const.AllowGLSLExtensionDirectiveMidShader =
driQueryOptionb(options, "allow_glsl_extension_directive_midshader");
+ ctx->Const.GLSLZeroInit = driQueryOptionb(options, "glsl_zero_init");
+
brw->dual_color_blend_by_location =
driQueryOptionb(options, "dual_color_blend_by_location");
}
diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
index 869119b..5aa28c6 100644
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -88,6 +88,10 @@ DRI_CONF_BEGIN
DRI_CONF_DESC(en, "Perform code generation at shader link time.")
DRI_CONF_OPT_END
DRI_CONF_SECTION_END
+
+ DRI_CONF_SECTION_MISCELLANEOUS
+ DRI_CONF_GLSL_ZERO_INIT("false")
+ DRI_CONF_SECTION_END
DRI_CONF_END
};
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 73ae55d..2210658 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3514,6 +3514,11 @@ struct gl_constants
GLboolean AllowGLSLExtensionDirectiveMidShader;
/**
+ * Force uninitialized variables to default to zero.
+ */
+ GLboolean GLSLZeroInit;
+
+ /**
* Does the driver support real 32-bit integers? (Otherwise, integers are
* simulated via floats.)
*/
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 412f598..e56d282 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -926,6 +926,8 @@ void st_init_extensions(struct pipe_screen *screen,
extensions->EXT_texture_integer = GL_FALSE;
}
+ consts->GLSLZeroInit = options->glsl_zero_init;
+
consts->UniformBooleanTrue = consts->NativeIntegers ? ~0U : fui(1.0f);
/* Below are the cases which cannot be moved into tables easily. */
--
2.7.4
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