1 files changed, 93 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..2647865d4
--- /dev/null
+++ b/src/video_core/shader/expr.cpp
@@ -0,0 +1,93 @@
+// Copyright 2019 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <memory>
+#include <variant>
+
+#include "video_core/shader/expr.h"
+
+namespace VideoCommon::Shader {
+namespace {
+bool ExprIsBoolean(const Expr& expr) {
+    return std::holds_alternative<ExprBoolean>(*expr);
+}
+
+bool ExprBooleanGet(const Expr& expr) {
+    return std::get_if<ExprBoolean>(expr.get())->value;
+}
+} // Anonymous namespace
+
+bool ExprAnd::operator==(const ExprAnd& b) const {
+    return (*operand1 == *b.operand1) && (*operand2 == *b.operand2);
+}
+
+bool ExprAnd::operator!=(const ExprAnd& b) const {
+    return !operator==(b);
+}
+
+bool ExprOr::operator==(const ExprOr& b) const {
+    return (*operand1 == *b.operand1) && (*operand2 == *b.operand2);
+}
+
+bool ExprOr::operator!=(const ExprOr& b) const {
+    return !operator==(b);
+}
+
+bool ExprNot::operator==(const ExprNot& b) const {
+    return *operand1 == *b.operand1;
+}
+
+bool ExprNot::operator!=(const ExprNot& b) const {
+    return !operator==(b);
+}
+
+Expr MakeExprNot(Expr first) {
+    if (std::holds_alternative<ExprNot>(*first)) {
+        return std::get_if<ExprNot>(first.get())->operand1;
+    }
+    return MakeExpr<ExprNot>(std::move(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>(std::move(first), std::move(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>(std::move(first), std::move(second));
+}
+
+bool ExprAreEqual(const Expr& first, const Expr& second) {
+    return (*first) == (*second);
+}
+
+bool ExprAreOpposite(const Expr& first, const 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;
+}
+
+bool ExprIsTrue(const Expr& first) {
+    if (ExprIsBoolean(first)) {
+        return ExprBooleanGet(first);
+    }
+    return false;
+}
+
+} // namespace VideoCommon::Shader