[Mesa-dev] [PATCH 27/87] glsl, i965: don't used shader cache when transform feedback enabled

[Timothy Arceri]

Note in future we may want to use the cache when in shader xfb
qualifiers override the API.
---
 src/compiler/glsl/linker.cpp                 | 15 ++++++++++++++-
 src/compiler/glsl/shader_cache.cpp           |  7 +++++++
 src/mesa/drivers/dri/i965/brw_shader_cache.c |  7 +++++++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index a6b9c26..ca758dc 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -4512,7 +4512,20 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog,
    tfeedback_decl *tfeedback_decls = NULL;
 
 #ifdef ENABLE_SHADER_CACHE
-   if (!is_cache_fallback && shader_cache_read_program_metadata(ctx, prog))
+   /* If transform feedback used on the program then compile all shaders. */
+   bool skip_cache = false;
+   if (prog->TransformFeedback.NumVarying > 0) {
+      for (unsigned i = 0; i < prog->NumShaders; i++) {
+         if (prog->Shaders[i]->ir) {
+            continue;
+         }
+         _mesa_glsl_compile_shader(ctx, prog->Shaders[i], false, false, true);
+      }
+      skip_cache = true;
+   }
+
+   if (!is_cache_fallback && !skip_cache &&
+       shader_cache_read_program_metadata(ctx, prog))
       return;
 #endif
 
diff --git a/src/compiler/glsl/shader_cache.cpp b/src/compiler/glsl/shader_cache.cpp
index 0cb8f85..3ed46f3 100644
--- a/src/compiler/glsl/shader_cache.cpp
+++ b/src/compiler/glsl/shader_cache.cpp
@@ -343,6 +343,13 @@ write_program_resource_data(struct blob *metadata,
          }
       }
       break;
+   case GL_TRANSFORM_FEEDBACK_BUFFER:
+   case GL_TRANSFORM_FEEDBACK_VARYING:
+      /* Don't bother caching transform feedback varyings/buffers as we will
+       * always relink a program which enables transform feedback.
+       * TODO: We may want to this for shaders that use the xfb_* qualifiers.
+       */
+      break;
    default:
       assert(!"Support for writting resource not yet implemneted.");
    }
diff --git a/src/mesa/drivers/dri/i965/brw_shader_cache.c b/src/mesa/drivers/dri/i965/brw_shader_cache.c
index aceaf32..751abb1 100644
--- a/src/mesa/drivers/dri/i965/brw_shader_cache.c
+++ b/src/mesa/drivers/dri/i965/brw_shader_cache.c
@@ -210,6 +210,13 @@ upload_cached_program(struct brw_context *brw, gl_shader_stage stage)
    if (prog == NULL)
       return;
 
+   /* FIXME: For now we don't read from the cache if transform feedback is
+    * enabled. However we should be able to use cached shaders when the xfb_*
+    * qualifiers were used to enable transform feedback.
+    */
+   if (prog->TransformFeedback.NumVarying > 0)
+      return;
+
    brw_vs_populate_key(brw, &vs_key);
    switch (stage) {
    case MESA_SHADER_VERTEX:
-- 
2.7.4