shader: Add integer attribute get optimization pass

Works around an nvidia driver bug, where casting the integer attributes to float and back to an integer always returned 0.

2 files changed, 18 insertions, 0 deletions

diff --git a/src/shader_recompiler/backend/glsl/emit_glsl_context_get_set.cpp b/src/shader_recompiler/backend/glsl/emit_glsl_context_get_set.cpp
index 6477bd192..5ef46d634 100644
--- a/src/shader_recompiler/backend/glsl/emit_glsl_context_get_set.cpp
+++ b/src/shader_recompiler/backend/glsl/emit_glsl_context_get_set.cpp
@@ -221,6 +221,22 @@ void EmitGetAttribute(EmitContext& ctx, IR::Inst& inst, IR::Attribute attr,
     }
 }
 
+void EmitGetAttributeU32(EmitContext& ctx, IR::Inst& inst, IR::Attribute attr, std::string_view) {
+    switch (attr) {
+    case IR::Attribute::PrimitiveId:
+        ctx.AddU32("{}=uint(gl_PrimitiveID);", inst);
+        break;
+    case IR::Attribute::InstanceId:
+        ctx.AddU32("{}=uint(gl_InstanceID);", inst);
+        break;
+    case IR::Attribute::VertexId:
+        ctx.AddU32("{}=uint(gl_VertexID);", inst);
+        break;
+    default:
+        throw NotImplementedException("Get U32 attribute {}", attr);
+    }
+}
+
 void EmitSetAttribute(EmitContext& ctx, IR::Attribute attr, std::string_view value,
                       [[maybe_unused]] std::string_view vertex) {
     if (IR::IsGeneric(attr)) {
diff --git a/src/shader_recompiler/backend/glsl/emit_glsl_instructions.h b/src/shader_recompiler/backend/glsl/emit_glsl_instructions.h
index f86502e4c..6cabbc717 100644
--- a/src/shader_recompiler/backend/glsl/emit_glsl_instructions.h
+++ b/src/shader_recompiler/backend/glsl/emit_glsl_instructions.h
@@ -60,6 +60,8 @@ void EmitGetCbufU32x2(EmitContext& ctx, IR::Inst& inst, const IR::Value& binding
                       const IR::Value& offset);
 void EmitGetAttribute(EmitContext& ctx, IR::Inst& inst, IR::Attribute attr,
                       std::string_view vertex);
+void EmitGetAttributeU32(EmitContext& ctx, IR::Inst& inst, IR::Attribute attr,
+                         std::string_view vertex);
 void EmitSetAttribute(EmitContext& ctx, IR::Attribute attr, std::string_view value,
                       std::string_view vertex);
 void EmitGetAttributeIndexed(EmitContext& ctx, IR::Inst& inst, std::string_view offset,