shader: Initial recompiler work

src/shader_recompiler/ir_opt/dead_code_elimination_pass.cpp

@@ -0,0 +1,23 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <ranges>
+
+#include "shader_recompiler/frontend/ir/basic_block.h"
+#include "shader_recompiler/frontend/ir/microinstruction.h"
+#include "shader_recompiler/ir_opt/passes.h"
+
+namespace Shader::Optimization {
+
+void DeadCodeEliminationPass(IR::Block& block) {
+    // We iterate over the instructions in reverse order.
+    // This is because removing an instruction reduces the number of uses for earlier instructions.
+    for (IR::Inst& inst : std::views::reverse(block)) {
+        if (!inst.HasUses() && !inst.MayHaveSideEffects()) {
+            inst.Invalidate();
+        }
+    }
+}
+
+} // namespace Shader::Optimization