[llvm-branch-commits] [clang] [CIR] Upstream __real__ for ComplexType (PR #144261)

[Amr Hesham via llvm-branch-commits]

https://github.com/AmrDeveloper created https://github.com/llvm/llvm-project/pull/144261

None

>From 9cbbfd20f045ca71e51d5bddd5e2bbe5a8ddd22f Mon Sep 17 00:00:00 2001
From: AmrDeveloper <amr96 at programmer.net>
Date: Sun, 15 Jun 2025 14:44:11 +0200
Subject: [PATCH] [CIR] Upstream __real__ for ComplexType

---
 clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp | 21 ++++++++++++++++++++
 clang/test/CIR/CodeGen/complex.cpp         | 23 ++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
index 75b4d2a637e6e..615a0e7bef556 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
@@ -603,6 +603,8 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
 
   mlir::Value VisitUnaryLNot(const UnaryOperator *e);
 
+  mlir::Value VisitUnaryReal(const UnaryOperator *e);
+
   mlir::Value VisitCXXThisExpr(CXXThisExpr *te) { return cgf.loadCXXThis(); }
 
   /// Emit a conversion from the specified type to the specified destination
@@ -1891,6 +1893,25 @@ mlir::Value ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *e) {
   return maybePromoteBoolResult(boolVal, cgf.convertType(e->getType()));
 }
 
+mlir::Value ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *e) {
+  // TODO(cir): handle scalar promotion.
+  Expr *op = e->getSubExpr();
+  if (op->getType()->isAnyComplexType()) {
+    // If it's an l-value, load through the appropriate subobject l-value.
+    // Note that we have to ask E because Op might be an l-value that
+    // this won't work for, e.g. an Obj-C property.
+    if (e->isGLValue())
+      return cgf.emitLoadOfLValue(cgf.emitLValue(e), e->getExprLoc())
+          .getScalarVal();
+
+    // Otherwise, calculate and project.
+    cgf.cgm.errorNYI(e->getSourceRange(),
+                     "VisitUnaryReal calculate and project");
+  }
+
+  return Visit(op);
+}
+
 /// Return the size or alignment of the type of argument of the sizeof
 /// expression as an integer.
 mlir::Value ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr(
diff --git a/clang/test/CIR/CodeGen/complex.cpp b/clang/test/CIR/CodeGen/complex.cpp
index 4bccf65cceb13..3d1e395d7613c 100644
--- a/clang/test/CIR/CodeGen/complex.cpp
+++ b/clang/test/CIR/CodeGen/complex.cpp
@@ -203,3 +203,26 @@ void foo11() {
 
 // OGCG: %[[COMPLEX:.*]] = alloca { double, double }, align 8
 // OGCG: %[[IMAG_PTR:.*]] = getelementptr inbounds nuw { double, double }, ptr %[[COMPLEX]], i32 0, i32 1
+
+void foo12() {
+  double _Complex c;
+  double real = __real__ c;
+}
+
+// CIR: %[[COMPLEX:.*]] = cir.alloca !cir.complex<!cir.double>, !cir.ptr<!cir.complex<!cir.double>>, ["c"]
+// CIR: %[[INIT:.*]] = cir.alloca !cir.double, !cir.ptr<!cir.double>, ["real", init]
+// CIR: %[[REAL_PTR:.*]] = cir.complex.real_ptr %[[COMPLEX]] : !cir.ptr<!cir.complex<!cir.double>> -> !cir.ptr<!cir.double>
+// CIR: %[[REAL:.*]] = cir.load{{.*}} %[[REAL_PTR]] : !cir.ptr<!cir.double>, !cir.double
+// CIR: cir.store{{.*}} %[[REAL]], %[[INIT]] : !cir.double, !cir.ptr<!cir.double>
+
+// LLVM: %[[COMPLEX:.*]] = alloca { double, double }, i64 1, align 8
+// LLVM: %[[INIT:.*]] = alloca double, i64 1, align 8
+// LLVM: %[[REAL_PTR:.*]] = getelementptr inbounds nuw { double, double }, ptr %[[COMPLEX]], i32 0, i32 0
+// LLVM: %[[REAL:.*]] = load double, ptr %[[REAL_PTR]], align 8
+// LLVM: store double %[[REAL]], ptr %[[INIT]], align 8
+
+// OGCG: %[[COMPLEX:.*]] = alloca { double, double }, align 8
+// OGCG: %[[INIT:.*]] = alloca double, align 8
+// OGCG: %[[REAL_PTR:.*]] = getelementptr inbounds nuw { double, double }, ptr %[[COMPLEX]], i32 0, i32 0
+// OGCG: %[[REAL:.*]] = load double, ptr %[[REAL_PTR]], align 8
+// OGCG: store double %[[REAL]], ptr %[[INIT]], align 8