[Mesa-dev] [PATCH 2/3] glsl: Lower UBO and SSBO access in glsl linker

[Kristian Høgsberg Kristensen]

All GLSL IR consumers run this lowering pass so we can move it to the
linker. This moves the pass up quite a bit, but that's the point: it
needs to run before we throw away information about per-component vector
access.

Signed-off-by: Kristian Høgsberg Kristensen <krh at bitplanet.net>
---
 src/glsl/linker.cpp                        | 8 ++++++++
 src/mesa/drivers/dri/i965/brw_link.cpp     | 2 --
 src/mesa/drivers/dri/i965/brw_shader.cpp   | 2 ++
 src/mesa/main/mtypes.h                     | 2 ++
 src/mesa/state_tracker/st_extensions.c     | 1 +
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 1 -
 6 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index c35d87a..ea6a3f3 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -4449,6 +4449,14 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
 
    /* FINISHME: Assign fragment shader output locations. */
 
+   for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
+      if (prog->_LinkedShaders[i] == NULL)
+	 continue;
+
+      if (ctx->Const.ShaderCompilerOptions[i].LowerBufferInterfaceBlocks)
+         lower_ubo_reference(prog->_LinkedShaders[i]);
+   }
+
 done:
    for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
       free(shader_list[i]);
diff --git a/src/mesa/drivers/dri/i965/brw_link.cpp b/src/mesa/drivers/dri/i965/brw_link.cpp
index f1e3860..2991173 100644
--- a/src/mesa/drivers/dri/i965/brw_link.cpp
+++ b/src/mesa/drivers/dri/i965/brw_link.cpp
@@ -157,8 +157,6 @@ process_glsl_ir(gl_shader_stage stage,
                  _mesa_shader_stage_to_abbrev(shader->Stage));
    }
 
-   lower_ubo_reference(shader);
-
    bool progress;
    do {
       progress = false;
diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index 4ea297a..5adc986 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -148,6 +148,8 @@ brw_compiler_create(void *mem_ctx, const struct brw_device_info *devinfo)
          compiler->glsl_compiler_options[i].EmitNoIndirectSampler = true;
 
       compiler->glsl_compiler_options[i].NirOptions = nir_options;
+
+      compiler->glsl_compiler_options[i].LowerBufferInterfaceBlocks = true;
    }
 
    return compiler;
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index d6c1eb8..800ad81 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -2874,6 +2874,8 @@ struct gl_shader_compiler_options
     */
    GLboolean OptimizeForAOS;
 
+   GLboolean LowerBufferInterfaceBlocks; /**< Lower UBO and SSBO access to intrinsics. */
+
    const struct nir_shader_compiler_options *NirOptions;
 };
 
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index bd7cbcc..bbb9027 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -254,6 +254,7 @@ void st_init_limits(struct pipe_screen *screen,
                                       PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT);
 
       options->LowerClipDistance = true;
+      options->LowerBufferInterfaceBlocks = true;
    }
 
    c->LowerTessLevel = true;
diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index ca00930..9ee6f8f 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -5822,7 +5822,6 @@ st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
                          (!ctx->Const.NativeIntegers ? INT_DIV_TO_MUL_RCP : 0) |
                          (options->EmitNoSat ? SAT_TO_CLAMP : 0));
 
-      lower_ubo_reference(prog->_LinkedShaders[i]);
       do_vec_index_to_cond_assign(ir);
       lower_vector_insert(ir, true);
       lower_quadop_vector(ir, false);
-- 
2.6.2