From 14ac0c2923c41df9c6fc4833d2a8e46a6efe5b59 Mon Sep 17 00:00:00 2001
From: ameerj <52414509+ameerj@users.noreply.github.com>
Date: Fri, 24 Dec 2021 20:00:28 -0500
Subject: 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.
---
 .../backend/spirv/emit_spirv_context_get_set.cpp   | 25 ++++++++++++++++++++++
 .../backend/spirv/emit_spirv_instructions.h        |  1 +
 2 files changed, 26 insertions(+)

(limited to 'src/shader_recompiler/backend/spirv')

diff --git a/src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp b/src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp
index 14f470812..8ea730c80 100644
--- a/src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp
+++ b/src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp
@@ -355,6 +355,31 @@ Id EmitGetAttribute(EmitContext& ctx, IR::Attribute attr, Id vertex) {
     }
 }
 
+Id EmitGetAttributeU32(EmitContext& ctx, IR::Attribute attr, Id) {
+    switch (attr) {
+    case IR::Attribute::PrimitiveId:
+        return ctx.OpLoad(ctx.U32[1], ctx.primitive_id);
+    case IR::Attribute::InstanceId:
+        if (ctx.profile.support_vertex_instance_id) {
+            return ctx.OpLoad(ctx.U32[1], ctx.instance_id);
+        } else {
+            const Id index{ctx.OpLoad(ctx.U32[1], ctx.instance_index)};
+            const Id base{ctx.OpLoad(ctx.U32[1], ctx.base_instance)};
+            return ctx.OpISub(ctx.U32[1], index, base);
+        }
+    case IR::Attribute::VertexId:
+        if (ctx.profile.support_vertex_instance_id) {
+            return ctx.OpLoad(ctx.U32[1], ctx.vertex_id);
+        } else {
+            const Id index{ctx.OpLoad(ctx.U32[1], ctx.vertex_index)};
+            const Id base{ctx.OpLoad(ctx.U32[1], ctx.base_vertex)};
+            return ctx.OpISub(ctx.U32[1], index, base);
+        }
+    default:
+        throw NotImplementedException("Read U32 attribute {}", attr);
+    }
+}
+
 void EmitSetAttribute(EmitContext& ctx, IR::Attribute attr, Id value, [[maybe_unused]] Id vertex) {
     const std::optional<OutAttr> output{OutputAttrPointer(ctx, attr)};
     if (!output) {
diff --git a/src/shader_recompiler/backend/spirv/emit_spirv_instructions.h b/src/shader_recompiler/backend/spirv/emit_spirv_instructions.h
index 6cd22dd3e..887112deb 100644
--- a/src/shader_recompiler/backend/spirv/emit_spirv_instructions.h
+++ b/src/shader_recompiler/backend/spirv/emit_spirv_instructions.h
@@ -53,6 +53,7 @@ Id EmitGetCbufU32(EmitContext& ctx, const IR::Value& binding, const IR::Value& o
 Id EmitGetCbufF32(EmitContext& ctx, const IR::Value& binding, const IR::Value& offset);
 Id EmitGetCbufU32x2(EmitContext& ctx, const IR::Value& binding, const IR::Value& offset);
 Id EmitGetAttribute(EmitContext& ctx, IR::Attribute attr, Id vertex);
+Id EmitGetAttributeU32(EmitContext& ctx, IR::Attribute attr, Id vertex);
 void EmitSetAttribute(EmitContext& ctx, IR::Attribute attr, Id value, Id vertex);
 Id EmitGetAttributeIndexed(EmitContext& ctx, Id offset, Id vertex);
 void EmitSetAttributeIndexed(EmitContext& ctx, Id offset, Id value, Id vertex);
-- 
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