1 files changed, 75 insertions, 0 deletions

diff --git a/src/video_core/shader/expr.cpp b/src/video_core/shader/expr.cpp
new file mode 100644
index 000000000..ebce6339b
--- /dev/null
+++ b/src/video_core/shader/expr.cpp
@@ -0,0 +1,75 @@
+// Copyright 2019 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <variant>
+
+#include "video_core/shader/expr.h"
+
+namespace VideoCommon::Shader {
+
+bool ExprAnd::operator==(const ExprAnd& b) const {
+    return (*operand1 == *b.operand1) && (*operand2 == *b.operand2);
+}
+
+bool ExprOr::operator==(const ExprOr& b) const {
+    return (*operand1 == *b.operand1) && (*operand2 == *b.operand2);
+}
+
+bool ExprNot::operator==(const ExprNot& b) const {
+    return (*operand1 == *b.operand1);
+}
+
+bool ExprIsBoolean(Expr expr) {
+    return std::holds_alternative<ExprBoolean>(*expr);
+}
+
+bool ExprBooleanGet(Expr expr) {
+    return std::get_if<ExprBoolean>(expr.get())->value;
+}
+
+Expr MakeExprNot(Expr first) {
+    if (std::holds_alternative<ExprNot>(*first)) {
+        return std::get_if<ExprNot>(first.get())->operand1;
+    }
+    return MakeExpr<ExprNot>(first);
+}
+
+Expr MakeExprAnd(Expr first, Expr second) {
+    if (ExprIsBoolean(first)) {
+        return ExprBooleanGet(first) ? second : first;
+    }
+    if (ExprIsBoolean(second)) {
+        return ExprBooleanGet(second) ? first : second;
+    }
+    return MakeExpr<ExprAnd>(first, second);
+}
+
+Expr MakeExprOr(Expr first, Expr second) {
+    if (ExprIsBoolean(first)) {
+        return ExprBooleanGet(first) ? first : second;
+    }
+    if (ExprIsBoolean(second)) {
+        return ExprBooleanGet(second) ? second : first;
+    }
+    return MakeExpr<ExprOr>(first, second);
+}
+
+bool ExprAreEqual(Expr first, Expr second) {
+    return (*first) == (*second);
+}
+
+bool ExprAreOpposite(Expr first, Expr second) {
+    if (std::holds_alternative<ExprNot>(*first)) {
+        return ExprAreEqual(std::get_if<ExprNot>(first.get())->operand1, second);
+    }
+    if (std::holds_alternative<ExprNot>(*second)) {
+        return ExprAreEqual(std::get_if<ExprNot>(second.get())->operand1, first);
+    }
+    return false;
+}
+
+} // namespace VideoCommon::Shader