From b541f5e5e333a8ec8c3569e02d67e59ad14217c2 Mon Sep 17 00:00:00 2001
From: FernandoS27
Date: Mon, 19 Apr 2021 01:03:38 +0200
Subject: shader: Implement VertexA stage

---
 src/shader_recompiler/ir_opt/dual_vertex_pass.cpp | 74 +++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 src/shader_recompiler/ir_opt/dual_vertex_pass.cpp

(limited to 'src/shader_recompiler/ir_opt/dual_vertex_pass.cpp')

diff --git a/src/shader_recompiler/ir_opt/dual_vertex_pass.cpp b/src/shader_recompiler/ir_opt/dual_vertex_pass.cpp
new file mode 100644
index 000000000..f35c6478a
--- /dev/null
+++ b/src/shader_recompiler/ir_opt/dual_vertex_pass.cpp
@@ -0,0 +1,74 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <ranges>
+#include <tuple>
+#include <type_traits>
+
+#include "common/bit_cast.h"
+#include "common/bit_util.h"
+#include "shader_recompiler/exception.h"
+#include "shader_recompiler/frontend/ir/ir_emitter.h"
+#include "shader_recompiler/ir_opt/passes.h"
+
+namespace Shader::Optimization {
+
+void VertexATransformPass(IR::Program& program) {
+    bool replaced_join{};
+    bool eliminated_epilogue{};
+    for (IR::Block* const block : program.post_order_blocks) {
+        for (IR::Inst& inst : block->Instructions()) {
+            switch (inst.GetOpcode()) {
+            case IR::Opcode::Return:
+                inst.ReplaceOpcode(IR::Opcode::Join);
+                replaced_join = true;
+                break;
+            case IR::Opcode::Epilogue:
+                inst.Invalidate();
+                eliminated_epilogue = true;
+                break;
+            default:
+                break;
+            }
+            if (replaced_join && eliminated_epilogue) {
+                return;
+            }
+        }
+    }
+}
+
+void VertexBTransformPass(IR::Program& program) {
+    for (IR::Block* const block : program.post_order_blocks | std::views::reverse) {
+        for (IR::Inst& inst : block->Instructions()) {
+            if (inst.GetOpcode() == IR::Opcode::Prologue) {
+                return inst.Invalidate();
+            }
+        }
+    }
+}
+
+void DualVertexJoinPass(IR::Program& program) {
+    const auto& blocks = program.blocks;
+    s64 s = static_cast<s64>(blocks.size()) - 1;
+    if (s < 1) {
+        throw NotImplementedException("Dual Vertex Join pass failed, expected atleast 2 blocks!");
+    }
+    for (s64 index = 0; index < s; index++) {
+        IR::Block* const current_block = blocks[index];
+        IR::Block* const next_block = blocks[index + 1];
+        for (IR::Inst& inst : current_block->Instructions()) {
+            if (inst.GetOpcode() == IR::Opcode::Join) {
+                IR::IREmitter ir{*current_block, IR::Block::InstructionList::s_iterator_to(inst)};
+                ir.Branch(next_block);
+                inst.Invalidate();
+                // only 1 join should exist
+                return;
+            }
+        }
+    }
+    throw NotImplementedException("Dual Vertex Join pass failed, no join present!");
+}
+
+} // namespace Shader::Optimization
-- 
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