[clang] [CIR] Upstream CXXRewrittenBinaryOperator for Scalar expr (PR #167210)

[Amr Hesham via cfe-commits]

https://github.com/AmrDeveloper created https://github.com/llvm/llvm-project/pull/167210

Upstream the CXXRewrittenBinaryOperator support for Scalar expr

>From 144da372a6b5945612848212e7a5e8c0238f2af4 Mon Sep 17 00:00:00 2001
From: Amr Hesham <amr96 at programmer.net>
Date: Sun, 9 Nov 2025 10:32:56 +0100
Subject: [PATCH] [CIR] Upstream CXXRewrittenBinaryOperator for Scalar expr

---
 clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp    |  4 ++
 .../CodeGen/cxx-rewritten-binary-operator.cpp | 39 +++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 clang/test/CIR/CodeGen/cxx-rewritten-binary-operator.cpp

diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
index 5eba5ba6c3df1..c1a36134d8942 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
@@ -438,6 +438,10 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
     return cgf.emitVAArg(ve);
   }
 
+  mlir::Value VisitCXXRewrittenBinaryOperator(CXXRewrittenBinaryOperator *e) {
+    return Visit(e->getSemanticForm());
+  }
+
   mlir::Value VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *e);
   mlir::Value
   VisitAbstractConditionalOperator(const AbstractConditionalOperator *e);
diff --git a/clang/test/CIR/CodeGen/cxx-rewritten-binary-operator.cpp b/clang/test/CIR/CodeGen/cxx-rewritten-binary-operator.cpp
new file mode 100644
index 0000000000000..ac4cac429cb0f
--- /dev/null
+++ b/clang/test/CIR/CodeGen/cxx-rewritten-binary-operator.cpp
@@ -0,0 +1,39 @@
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --input-file=%t-cir.ll %s -check-prefix=LLVM
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -Wno-unused-value -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=OGCG
+
+struct HasOpEq {
+  bool operator==(const HasOpEq &) const;
+};
+
+void cxx_rewritten_binary_operator_scalar_expr() {
+  HasOpEq a;
+  HasOpEq b;
+  bool neq = a != b;
+}
+
+// CIR: %[[A_ADDR:.*]] = cir.alloca !rec_HasOpEq, !cir.ptr<!rec_HasOpEq>, ["a"]
+// CIR: %[[B_ADDR:.*]] = cir.alloca !rec_HasOpEq, !cir.ptr<!rec_HasOpEq>, ["b"]
+// CIR: %[[NEQ_ADDR:.*]] = cir.alloca !cir.bool, !cir.ptr<!cir.bool>, ["neq", init]
+// CIR: %[[EQ:.*]] = cir.call @_ZNK7HasOpEqeqERKS_(%[[A_ADDR]], %[[B_ADDR]]) : (!cir.ptr<!rec_HasOpEq>, !cir.ptr<!rec_HasOpEq>) -> !cir.bool
+// CIR: %[[NEQ:.*]] = cir.unary(not, %[[EQ]]) : !cir.bool, !cir.bool
+// CIR: cir.store{{.*}} %[[NEQ]], %[[NEQ_ADDR]] : !cir.bool, !cir.ptr<!cir.bool>
+
+// LLVM: %[[A_ADDR:.*]] = alloca %struct.HasOpEq, i64 1, align 1
+// LLVM: %[[B_ADDR:.*]] = alloca %struct.HasOpEq, i64 1, align 1
+// LLVM: %[[NEQ_ADDR:.*]] = alloca i8, i64 1, align 1
+// LLVM: %[[EQ:.*]] = call i1 @_ZNK7HasOpEqeqERKS_(ptr %[[A_ADDR]], ptr %[[B_ADDR]])
+// LLVM: %[[NEQ_I1:.*]] = xor i1 %[[EQ]], true
+// LLVM: %[[NEQ:.*]] = zext i1 %[[NEQ_I1]] to i8
+// LLVM: store i8 %[[NEQ]], ptr %[[NEQ_ADDR]], align 1
+
+// OGCG: %[[A_ADDR:.*]] = alloca %struct.HasOpEq, align 1
+// OGCG: %[[B_ADDR:.*]] = alloca %struct.HasOpEq, align 1
+// OGCG: %[[NEQ_ADDR:.*]] = alloca i8, align 1
+// OGCG: %[[EQ:.*]] = call {{.*}} zeroext i1 @_ZNK7HasOpEqeqERKS_(ptr {{.*}} %[[A_ADDR]], ptr {{.*}} %[[B_ADDR]])
+// OGCG: %[[NEQ_I1:.*]] = xor i1 %[[EQ]], true
+// OGCG: %[[NEQ:.*]] = zext i1 %[[NEQ_I1]] to i8
+// OGCG: store i8 %[[NEQ]], ptr %[[NEQ_ADDR]], align 1