[Mesa-dev] [PATCH 27/88] glsl, i965: add support for caching shaders with xfb qualifiers

[Timothy Arceri]

For now this disables the shader cache when transform feedback is enabled
via the GL API.
---
 src/compiler/glsl/linker.cpp                 | 15 ++++-
 src/compiler/glsl/shader_cache.cpp           | 87 ++++++++++++++++++++++++++++
 src/mesa/drivers/dri/i965/brw_shader_cache.c |  7 +++
 3 files changed, 108 insertions(+), 1 deletion(-)

diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index d71f96c..13336f8 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -4629,7 +4629,20 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog,
    unsigned int num_explicit_uniform_locs = 0;
 
 #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 0020963..66506af 100644
--- a/src/compiler/glsl/shader_cache.cpp
+++ b/src/compiler/glsl/shader_cache.cpp
@@ -126,6 +126,65 @@ decode_type_from_blob(struct blob_reader *blob)
 }
 
 static void
+write_xfb(struct blob *metadata, struct gl_shader_program *prog)
+{
+   struct gl_transform_feedback_info *ltf = &prog->LinkedTransformFeedback;
+
+   blob_write_uint32(metadata, ltf->NumOutputs);
+   blob_write_uint32(metadata, ltf->ActiveBuffers);
+   blob_write_uint32(metadata, ltf->NumVarying);
+
+   blob_write_bytes(metadata, ltf->Outputs,
+                    sizeof(struct gl_transform_feedback_output) *
+                       ltf->NumOutputs);
+
+   for (int i = 0; i < ltf->NumVarying; i++) {
+      blob_write_string(metadata, ltf->Varyings[i].Name);
+      blob_write_uint32(metadata, ltf->Varyings[i].Type);
+      blob_write_uint32(metadata, ltf->Varyings[i].BufferIndex);
+      blob_write_uint32(metadata, ltf->Varyings[i].Size);
+      blob_write_uint32(metadata, ltf->Varyings[i].Offset);
+   }
+
+   blob_write_bytes(metadata, ltf->Buffers,
+                    sizeof(struct gl_transform_feedback_buffer) *
+                       MAX_FEEDBACK_BUFFERS);
+}
+
+static void
+read_xfb(struct blob_reader *metadata, struct gl_shader_program *prog)
+{
+   struct gl_transform_feedback_info *ltf = &prog->LinkedTransformFeedback;
+
+   ltf->NumOutputs = blob_read_uint32(metadata);
+   ltf->ActiveBuffers = blob_read_uint32(metadata);
+   ltf->NumVarying = blob_read_uint32(metadata);
+
+   ltf->Outputs = rzalloc_array(prog, struct gl_transform_feedback_output,
+                                ltf->NumOutputs);
+
+   blob_copy_bytes(metadata, (uint8_t *) ltf->Outputs,
+                   sizeof(struct gl_transform_feedback_output) *
+                      ltf->NumOutputs);
+
+   ltf->Varyings = rzalloc_array(prog,
+                                 struct gl_transform_feedback_varying_info,
+                                 ltf->NumVarying);
+
+   for (int i = 0; i < ltf->NumVarying; i++) {
+      ltf->Varyings[i].Name = ralloc_strdup(prog, blob_read_string(metadata));
+      ltf->Varyings[i].Type = blob_read_uint32(metadata);
+      ltf->Varyings[i].BufferIndex = blob_read_uint32(metadata);
+      ltf->Varyings[i].Size = blob_read_uint32(metadata);
+      ltf->Varyings[i].Offset = blob_read_uint32(metadata);
+   }
+
+   blob_copy_bytes(metadata, (uint8_t *) ltf->Buffers,
+                   sizeof(struct gl_transform_feedback_buffer) *
+                      MAX_FEEDBACK_BUFFERS);
+}
+
+static void
 write_uniforms(struct blob *metadata, struct gl_shader_program *prog)
 {
    uint32_t i;
@@ -343,6 +402,24 @@ write_program_resource_data(struct blob *metadata,
          }
       }
       break;
+   case GL_TRANSFORM_FEEDBACK_BUFFER:
+      for (unsigned i = 0; i < MAX_FEEDBACK_BUFFERS; i++) {
+         if (((gl_transform_feedback_buffer *)res->Data)->Binding ==
+             prog->LinkedTransformFeedback.Buffers[i].Binding) {
+            blob_write_uint32(metadata, i);
+            break;
+         }
+      }
+      break;
+   case GL_TRANSFORM_FEEDBACK_VARYING:
+      for (int i = 0; i < prog->LinkedTransformFeedback.NumVarying; i++) {
+         if (strcmp(((gl_transform_feedback_varying_info *)res->Data)->Name,
+                    prog->LinkedTransformFeedback.Varyings[i].Name) == 0) {
+            blob_write_uint32(metadata, i);
+            break;
+         }
+      }
+      break;
    default:
       assert(!"Support for writting resource not yet implemented.");
    }
@@ -379,6 +456,12 @@ read_program_resource_data(struct blob_reader *metadata,
    case GL_UNIFORM:
       res->Data = &prog->UniformStorage[blob_read_uint32(metadata)];
       break;
+   case GL_TRANSFORM_FEEDBACK_BUFFER:
+      res->Data = &prog->LinkedTransformFeedback.Buffers[blob_read_uint32(metadata)];
+      break;
+   case GL_TRANSFORM_FEEDBACK_VARYING:
+      res->Data = &prog->LinkedTransformFeedback.Varyings[blob_read_uint32(metadata)];
+      break;
    default:
       assert(!"Support for reading resource not yet implemented.");
    }
@@ -584,6 +667,8 @@ shader_cache_write_program_metadata(struct gl_context *ctx,
 
    metadata = blob_create(NULL);
 
+   write_xfb(metadata, prog);
+
    write_uniforms(metadata, prog);
 
    write_hash_tables(metadata, prog);
@@ -681,6 +766,8 @@ shader_cache_read_program_metadata(struct gl_context *ctx,
 
    assert(prog->UniformStorage == NULL);
 
+   read_xfb(&metadata, prog);
+
    read_uniforms(&metadata, prog);
 
    read_hash_tables(&metadata, prog);
diff --git a/src/mesa/drivers/dri/i965/brw_shader_cache.c b/src/mesa/drivers/dri/i965/brw_shader_cache.c
index aceaf32..f64269e 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 via the API. However the shader cache does support transform
+    * feedback when enabled via in shader xfb qualifiers.
+    */
+   if (prog->TransformFeedback.NumVarying > 0)
+      return;
+
    brw_vs_populate_key(brw, &vs_key);
    switch (stage) {
    case MESA_SHADER_VERTEX:
-- 
2.7.4