glsl: add support for caching shaders with xfb qualifiers

For now this disables the shader cache when transform feedback is
enabled via the GL API as we don't currently allow for it when
generating the sha for the shader.

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

src/compiler/glsl/linker.cpp

@@ -4621,7 +4621,19 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       return;
    }
 
-   if (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 (!skip_cache && shader_cache_read_program_metadata(ctx, prog))
       return;
 
    void *mem_ctx = ralloc_context(NULL); // temporary linker context

src/compiler/glsl/shader_cache.cpp

@@ -207,6 +207,84 @@ decode_type_from_blob(struct blob_reader *blob)
    }
 }
 
+static void
+write_xfb(struct blob *metadata, struct gl_shader_program *shProg)
+{
+   struct gl_program *prog = shProg->last_vert_prog;
+
+   if (!prog) {
+      blob_write_uint32(metadata, ~0u);
+      return;
+   }
+
+   struct gl_transform_feedback_info *ltf = prog->sh.LinkedTransformFeedback;
+
+   blob_write_uint32(metadata, prog->info.stage);
+
+   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 *shProg)
+{
+   unsigned xfb_stage = blob_read_uint32(metadata);
+
+   if (xfb_stage == ~0u)
+      return;
+
+   struct gl_program *prog = shProg->_LinkedShaders[xfb_stage]->Program;
+   struct gl_transform_feedback_info *ltf =
+      rzalloc(prog, struct gl_transform_feedback_info);
+
+   prog->sh.LinkedTransformFeedback = ltf;
+   shProg->last_vert_prog = prog;
+
+   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)
 {
@@ -458,6 +536,24 @@ 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->last_vert_prog->sh.LinkedTransformFeedback->Buffers[i].Binding) {
+            blob_write_uint32(metadata, i);
+            break;
+         }
+      }
+      break;
+   case GL_TRANSFORM_FEEDBACK_VARYING:
+      for (int i = 0; i < prog->last_vert_prog->sh.LinkedTransformFeedback->NumVarying; i++) {
+         if (strcmp(((gl_transform_feedback_varying_info *)res->Data)->Name,
+                    prog->last_vert_prog->sh.LinkedTransformFeedback->Varyings[i].Name) == 0) {
+            blob_write_uint32(metadata, i);
+            break;
+         }
+      }
+      break;
    default:
       assert(!"Support for writing resource not yet implemented.");
    }
@@ -497,6 +593,14 @@ read_program_resource_data(struct blob_reader *metadata,
    case GL_UNIFORM:
       res->Data = &prog->data->UniformStorage[blob_read_uint32(metadata)];
       break;
+   case GL_TRANSFORM_FEEDBACK_BUFFER:
+      res->Data = &prog->last_vert_prog->
+         sh.LinkedTransformFeedback->Buffers[blob_read_uint32(metadata)];
+      break;
+   case GL_TRANSFORM_FEEDBACK_VARYING:
+      res->Data = &prog->last_vert_prog->
+         sh.LinkedTransformFeedback->Varyings[blob_read_uint32(metadata)];
+      break;
    default:
       assert(!"Support for reading resource not yet implemented.");
    }
@@ -709,6 +813,8 @@ shader_cache_write_program_metadata(struct gl_context *ctx,
       }
    }
 
+   write_xfb(metadata, prog);
+
    write_uniform_remap_table(metadata, prog);
 
    write_program_resource_list(metadata, prog);
@@ -814,6 +920,8 @@ shader_cache_read_program_metadata(struct gl_context *ctx,
                                        &metadata);
    }
 
+   read_xfb(&metadata, prog);
+
    read_uniform_remap_table(&metadata, prog);
 
    read_program_resource_list(&metadata, prog);