From 360e897ccd53bf863cea1ad6184d35e9b6ffbf40 Mon Sep 17 00:00:00 2001
From: Fernando Sahmkow <fsahmkow27@gmail.com>
Date: Sun, 18 Jul 2021 23:06:12 +0200
Subject: [PATCH] ShaderDecompiler: Add initial support for rescaling.
---
.../ir_opt/rescaling_pass.cpp | 72 +++++++++++++++++++
src/shader_recompiler/shader_info.h | 1 +
2 files changed, 73 insertions(+)
create mode 100644 src/shader_recompiler/ir_opt/rescaling_pass.cpp
diff --git a/src/shader_recompiler/ir_opt/rescaling_pass.cpp b/src/shader_recompiler/ir_opt/rescaling_pass.cpp
new file mode 100644
index 0000000000..d3ae3f159a
--- /dev/null
+++ b/src/shader_recompiler/ir_opt/rescaling_pass.cpp
@@ -0,0 +1,72 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/alignment.h"
+#include "shader_recompiler/environment.h"
+#include "shader_recompiler/frontend/ir/modifiers.h"
+#include "shader_recompiler/frontend/ir/program.h"
+#include "shader_recompiler/frontend/ir/value.h"
+#include "shader_recompiler/ir_opt/passes.h"
+#include "shader_recompiler/shader_info.h"
+
+namespace Shader::Optimization {
+namespace {
+
+void PatchFragCoord(IR::Inst& inst) {
+ IR::IREmitter ir{block, IR::Block::InstructionList::s_iterator_to(inst)};
+ const IR::F32 inv_resolution_factor = IR::F32{Settings::values.resolution_info.down_factor};
+ const IR::F32 new_get_attribute = ir.GetAttribute(inst.Arg(0).Attribute());
+ const IR::F32 mul = ir.FMul(new_get_attribute, inv_resolution_factor);
+ const IR::U1 should_rescale = IR::U1{true};
+ const IR::F32 selection = ir.Select(should_rescale, mul, new_get_attribute);
+ inst.ReplaceUsesWith(selection);
+}
+
+void Visit(Info& info, IR::Inst& inst) {
+ info.requires_rescaling_uniform = false;
+ switch (inst.GetOpcode()) {
+ case IR::Opcode::GetAttribute: {
+ conast auto attrib = inst.Arg(0).Attribute();
+ const bool is_frag =
+ attrib == IR::Attribute::PositionX || attrib == IR::Attribute::PositionY;
+ const bool must_path = is_frag && program.stage == Stage::Fragment;
+ if (must_path) {
+ PatchFragCoord(inst);
+ info.requires_rescaling_uniform = true;
+ }
+ break;
+ }
+ case IR::Opcode::ImageQueryDimensions: {
+ info.requires_rescaling_uniform |= true;
+ break;
+ }
+ case IR::Opcode::ImageFetch: {
+ info.requires_rescaling_uniform |= true;
+ break;
+ }
+ case IR::Opcode::ImageRead: {
+ info.requires_rescaling_uniform |= true;
+ break;
+ }
+ case IR::Opcode::ImageWrite: {
+ info.requires_rescaling_uniform |= true;
+ break;
+ }
+ default:
+ break;
+ }
+}
+
+} // namespace
+
+void RescalingPass(Environment& env, IR::Program& program) {
+ Info& info{program.info};
+ for (IR::Block* const block : program.post_order_blocks) {
+ for (IR::Inst& inst : block->Instructions()) {
+ Visit(info, inst);
+ }
+ }
+}
+
+} // namespace Shader::Optimization
diff --git a/src/shader_recompiler/shader_info.h b/src/shader_recompiler/shader_info.h
index 4ef4dbd406..e7981a08cd 100644
--- a/src/shader_recompiler/shader_info.h
+++ b/src/shader_recompiler/shader_info.h
@@ -172,6 +172,7 @@ struct Info {
bool uses_global_memory{};
bool uses_atomic_image_u32{};
bool uses_shadow_lod{};
+ bool requires_rescaling_uniform{};
IR::Type used_constant_buffer_types{};
IR::Type used_storage_buffer_types{};