From 3ebf1fcacdb1fd2db58de7f3ad7f4fbd9a89fd0f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=80=9CAmr?= <amr96@programmer.net>
Date: Fri, 26 Sep 2025 23:02:12 +0200
Subject: [PATCH] [CIR] Implement UO real on result from real with type
 promotion

---
 clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp |  7 ++--
 clang/test/CIR/CodeGen/complex.cpp         | 37 ++++++++++++++++++++++
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
index 3b22c689ecd9f..62af9828f0a45 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
@@ -1278,9 +1278,7 @@ mlir::Value ScalarExprEmitter::emitPromoted(const Expr *e,
                        "ScalarExprEmitter::emitPromoted unary imag");
       return {};
     case UO_Real:
-      cgf.cgm.errorNYI(e->getSourceRange(),
-                       "ScalarExprEmitter::emitPromoted unary real");
-      return {};
+      return VisitRealImag(uo, promotionType);
     case UO_Minus:
       return emitUnaryPlusOrMinus(uo, cir::UnaryOpKind::Minus, promotionType);
     case UO_Plus:
@@ -2132,6 +2130,9 @@ mlir::Value ScalarExprEmitter::VisitRealImag(const UnaryOperator *e,
     // this won't work for, e.g. an Obj-C property
     mlir::Value complex = cgf.emitComplexExpr(op);
     if (e->isGLValue() && !promotionTy.isNull()) {
+      promotionTy = promotionTy->isAnyComplexType()
+                        ? promotionTy
+                        : cgf.getContext().getComplexType(promotionTy);
       complex = cgf.emitPromotedValue(complex, promotionTy);
     }
 
diff --git a/clang/test/CIR/CodeGen/complex.cpp b/clang/test/CIR/CodeGen/complex.cpp
index f036b7e6a971d..e90163172d2df 100644
--- a/clang/test/CIR/CodeGen/complex.cpp
+++ b/clang/test/CIR/CodeGen/complex.cpp
@@ -1233,3 +1233,40 @@ void imag_on_const_scalar() {
 // OGCG: %[[A_ADDR:.*]] = alloca float, align 4
 // OGCG: %[[B_ADDR:.*]] = alloca float, align 4
 // OGCG: store float 0.000000e+00, ptr %[[B_ADDR]], align 4
+
+void real_on_scalar_from_real_with_type_promotion() {
+  _Float16 _Complex a;
+  _Float16 b = __real__(__real__ a);
+}
+
+// CIR: %[[A_ADDR:.*]] = cir.alloca !cir.complex<!cir.f16>, !cir.ptr<!cir.complex<!cir.f16>>, ["a"]
+// CIR: %[[B_ADDR:.*]] = cir.alloca !cir.f16, !cir.ptr<!cir.f16>, ["b", init]
+// CIR: %[[TMP_A:.*]] = cir.load{{.*}} %[[A_ADDR]] : !cir.ptr<!cir.complex<!cir.f16>>, !cir.complex<!cir.f16>
+// CIR: %[[A_REAL:.*]] = cir.complex.real %[[TMP_A]] : !cir.complex<!cir.f16> -> !cir.f16
+// CIR: %[[A_IMAG:.*]] = cir.complex.imag %[[TMP_A]] : !cir.complex<!cir.f16> -> !cir.f16
+// CIR: %[[A_REAL_F32:.*]] = cir.cast(floating, %[[A_REAL]] : !cir.f16), !cir.float
+// CIR: %[[A_IMAG_F32:.*]] = cir.cast(floating, %[[A_IMAG]] : !cir.f16), !cir.float
+// CIR: %[[A_COMPLEX_F32:.*]] = cir.complex.create %[[A_REAL_F32]], %[[A_IMAG_F32]] : !cir.float -> !cir.complex<!cir.float>
+// CIR: %[[A_REAL_F32:.*]] = cir.complex.real %[[A_COMPLEX_F32]] : !cir.complex<!cir.float> -> !cir.float
+// CIR: %[[A_REAL_F16:.*]] = cir.cast(floating, %[[A_REAL_F32]] : !cir.float), !cir.f16
+// CIR: cir.store{{.*}} %[[A_REAL_F16]], %[[B_ADDR]] : !cir.f16, !cir.ptr<!cir.f16>
+
+// LLVM: %[[A_ADDR:.*]] = alloca { half, half }, i64 1, align 2
+// LLVM: %[[B_ADDR]] = alloca half, i64 1, align 2
+// LLVM: %[[TMP_A:.*]] = load { half, half }, ptr %[[A_ADDR]], align 2
+// LLVM: %[[A_REAL:.*]] = extractvalue { half, half } %[[TMP_A]], 0
+// LLVM: %[[A_IMAG:.*]] = extractvalue { half, half } %[[TMP_A]], 1
+// LLVM: %[[A_REAL_F32:.*]] = fpext half %[[A_REAL]] to float
+// LLVM: %[[A_IMAG_F32:.*]] = fpext half %[[A_IMAG]] to float
+// LLVM: %[[TMP_A_COMPLEX_F32:.*]] = insertvalue { float, float } {{.*}}, float %[[A_REAL_F32]], 0
+// LLVM: %[[A_COMPLEX_F32:.*]] = insertvalue { float, float } %[[TMP_A_COMPLEX_F32]], float %[[A_IMAG_F32]], 1
+// LLVM: %[[A_REAL_F16:.*]] = fptrunc float %[[A_REAL_F32]] to half
+// LLVM: store half %[[A_REAL_F16]], ptr %[[B_ADDR]], align 2
+
+// OGCG: %[[A_ADDR:.*]] = alloca { half, half }, align 2
+// OGCG: %[[B_ADDR:.*]] = alloca half, align 2
+// OGCG: %[[A_REAL_PTR:.*]] = getelementptr inbounds nuw { half, half }, ptr %[[A_ADDR]], i32 0, i32 0
+// OGCG: %[[A_REAL:.*]] = load half, ptr %[[A_REAL_PTR]], align 2
+// OGCG: %[[A_REAL_F32:.*]] = fpext half %[[A_REAL]] to float
+// OGCG: %[[A_REAL_F16:.*]] = fptrunc float %[[A_REAL_F32]] to half
+// OGCG: store half %[[A_REAL_F16]], ptr %[[B_ADDR]], align 2