nir: Try to make sense of the nir_shader_compiler_options code.

The code in glsl_to_nir is entirely dead, as we translate from GLSL to
NIR at link time, when there isn't a _mesa_glsl_parse_state to pass,
so every caller passes NULL.

glsl_to_nir seems like the wrong place to try and create the shader
compiler options structure anyway - tgsi_to_nir, prog_to_nir, and other
translators all would have to duplicate that code.  The driver should
set this up once with whatever settings it wants, and pass it in.

Eric also added a NirOptions field to ctx->Const.ShaderCompilerOptions[]
and left a comment saying: "The memory for the options is expected to be
kept in a single static copy by the driver."  This suggests the plan was
to do exactly that.  That pointer was not marked const, however, and the
dead code used a mix of static structures and ralloced ones.

This patch deletes the dead code in glsl_to_nir, instead making it take
the shader compiler options as a mandatory argument.  It creates an
(empty) options struct in the i965 driver, and makes NirOptions point
to that.  It marks the pointer const so that we can actually do so
without generating "discards const qualifier" compiler warnings.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

diff --git a/src/glsl/nir/glsl_to_nir.cpp b/src/glsl/nir/glsl_to_nir.cpp
index b82e5c7ac18a7ac225622280764f22ef6e33716f..7e40ef485a1a732cbdde0fc5b4bd7b3274fb8b46 100644 (file)
--- a/src/glsl/nir/glsl_to_nir.cpp
+++ b/src/glsl/nir/glsl_to_nir.cpp
@@ -124,34 +124,10 @@ private:
 
 }; /* end of anonymous namespace */
 
-static const nir_shader_compiler_options default_options = {
-};
-
 nir_shader *
-glsl_to_nir(exec_list *ir, _mesa_glsl_parse_state *state,
-            bool native_integers)
+glsl_to_nir(exec_list *ir, bool native_integers,
+            const nir_shader_compiler_options *options)
 {
-   const nir_shader_compiler_options *options;
-
-   if (state) {
-      struct gl_context *ctx = state->ctx;
-      struct gl_shader_compiler_options *gl_options =
-         &ctx->Const.ShaderCompilerOptions[state->stage];
-
-      if (!gl_options->NirOptions) {
-         nir_shader_compiler_options *new_options =
-            rzalloc(ctx, nir_shader_compiler_options);
-         options = gl_options->NirOptions = new_options;
-
-         if (gl_options->EmitNoPow)
-            new_options->lower_fpow = true;
-      } else {
-         options = gl_options->NirOptions;
-      }
-   } else {
-      options = &default_options;
-   }
-
    nir_shader *shader = nir_shader_create(NULL, options);
 
    nir_visitor v1(shader, native_integers);

diff --git a/src/glsl/nir/glsl_to_nir.h b/src/glsl/nir/glsl_to_nir.h
index 58b2cee6a4812e26a09c9b2e457c98a4b1e031d5..730094552ce61899ca8f1ae5ff6816f1e1324d55 100644 (file)
--- a/src/glsl/nir/glsl_to_nir.h
+++ b/src/glsl/nir/glsl_to_nir.h
@@ -32,8 +32,8 @@
 extern "C" {
 #endif
 
-nir_shader *glsl_to_nir(exec_list * ir, _mesa_glsl_parse_state *state,
-                        bool native_integers);
+nir_shader *glsl_to_nir(exec_list *ir, bool native_integers,
+                        const nir_shader_compiler_options *options);
 
 #ifdef __cplusplus
 }

diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index 972e458f4377159e9b1e4e4ca65b2c4dd3538948..8141b45f73561553cb52102a81c98755dfe382f3 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -68,6 +68,8 @@
 #include "tnl/t_pipeline.h"
 #include "util/ralloc.h"
 
+#include "glsl/nir/nir.h"
+
 /***************************************
  * Mesa's Driver Functions
  ***************************************/
@@ -549,6 +551,8 @@ brw_initialize_context_constants(struct brw_context *brw)
       ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxInputComponents = 128;
    }
 
+   static const nir_shader_compiler_options nir_options = {};
+
    /* We want the GLSL compiler to emit code that uses condition codes */
    for (int i = 0; i < MESA_SHADER_STAGES; i++) {
       ctx->Const.ShaderCompilerOptions[i].MaxIfDepth = brw->gen < 6 ? 16 : UINT_MAX;
@@ -562,6 +566,7 @@ brw_initialize_context_constants(struct brw_context *brw)
         (i == MESA_SHADER_FRAGMENT);
       ctx->Const.ShaderCompilerOptions[i].EmitNoIndirectUniform = false;
       ctx->Const.ShaderCompilerOptions[i].LowerClipDistance = true;
+      ctx->Const.ShaderCompilerOptions[i].NirOptions = &nir_options;
    }
 
    ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].OptimizeForAOS = true;

diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
index a0300aa36d5d7370cc35e2785a9962c668448c8a..e24bf92eef5dd381e2feb19fe597c3deef858b5d 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
@@ -82,9 +82,12 @@ count_nir_instrs(nir_shader *nir)
 void
 fs_visitor::emit_nir_code()
 {
+   const nir_shader_compiler_options *options =
+      ctx->Const.ShaderCompilerOptions[stage].NirOptions;
+
    /* first, lower the GLSL IR shader to NIR */
    lower_output_reads(shader->base.ir);
-   nir_shader *nir = glsl_to_nir(shader->base.ir, NULL, true);
+   nir_shader *nir = glsl_to_nir(shader->base.ir, true, options);
    nir_validate_shader(nir);
 
    nir_lower_global_vars_to_local(nir);

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index efeee8bff675ec3d6827d3bc737064810421069d..c43c6ac6710f352f5d407dcfd71c3bb3d60839a5 100644 (file)
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3036,7 +3036,7 @@ struct gl_shader_compiler_options
 
    struct gl_sl_pragmas DefaultPragmas; /**< Default #pragma settings */
 
-   struct nir_shader_compiler_options *NirOptions;
+   const struct nir_shader_compiler_options *NirOptions;
 };