diff --git a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
index 476f994959285..61d1c54ee9ec9 100644
--- a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
@@ -125,7 +125,7 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID,
     mlir::Value real = emitScalarExpr(e->getArg(0));
     mlir::Value imag = emitScalarExpr(e->getArg(1));
     mlir::Value complex = builder.createComplexCreate(loc, real, imag);
-    return RValue::get(complex);
+    return RValue::getComplex(complex);
   }
 
   case Builtin::BI__builtin_creal:
@@ -150,6 +150,18 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID,
     return RValue::get(imag);
   }
 
+  case Builtin::BI__builtin_conj:
+  case Builtin::BI__builtin_conjf:
+  case Builtin::BI__builtin_conjl:
+  case Builtin::BIconj:
+  case Builtin::BIconjf:
+  case Builtin::BIconjl: {
+    mlir::Value complex = emitComplexExpr(e->getArg(0));
+    mlir::Value conj = builder.createUnaryOp(getLoc(e->getExprLoc()),
+                                             cir::UnaryOpKind::Not, complex);
+    return RValue::getComplex(conj);
+  }
+
   case Builtin::BI__builtin_clrsb:
   case Builtin::BI__builtin_clrsbl:
   case Builtin::BI__builtin_clrsbll:
diff --git a/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp b/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
index 6663f5ea1e758..9f36be5397ad8 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
@@ -231,8 +231,7 @@ mlir::Value ComplexExprEmitter::VisitBinComma(const BinaryOperator *e) {
 mlir::Value ComplexExprEmitter::VisitCallExpr(const CallExpr *e) {
   if (e->getCallReturnType(cgf.getContext())->isReferenceType())
     return emitLoadOfLValue(e);
-
-  return cgf.emitCallExpr(e).getValue();
+  return cgf.emitCallExpr(e).getComplexValue();
 }
 
 mlir::Value ComplexExprEmitter::VisitCastExpr(CastExpr *e) {
diff --git a/clang/lib/CIR/CodeGen/CIRGenValue.h b/clang/lib/CIR/CodeGen/CIRGenValue.h
index 0a6dba5e80a62..0832c4141a10f 100644
--- a/clang/lib/CIR/CodeGen/CIRGenValue.h
+++ b/clang/lib/CIR/CodeGen/CIRGenValue.h
@@ -58,6 +58,12 @@ class RValue {
     return value;
   }
 
+  /// Return the value of this complex value.
+  mlir::Value getComplexValue() const {
+    assert(isComplex() && "Not a complex!");
+    return value;
+  }
+
   /// Return the value of the address of the aggregate.
   Address getAggregateAddress() const {
     assert(isAggregate() && "Not an aggregate!");
diff --git a/clang/test/CIR/CodeGen/complex-builtins.cpp b/clang/test/CIR/CodeGen/complex-builtins.cpp
index f0d12d0ef6663..811af47a704f5 100644
--- a/clang/test/CIR/CodeGen/complex-builtins.cpp
+++ b/clang/test/CIR/CodeGen/complex-builtins.cpp
@@ -83,3 +83,39 @@ void foo3() {
 // OGCG: %[[A_IMAG_PTR:.*]] = getelementptr inbounds nuw { double, double }, ptr %[[COMPLEX]], i32 0, i32 1
 // OGCG: %[[A_IMAG:.*]] = load double, ptr %[[A_IMAG_PTR]], align 8
 // OGCG: store double %[[A_IMAG]], ptr %[[INIT]], align 8
+
+void foo4() {
+  float _Complex a;
+  float _Complex b = __builtin_conjf(a);
+}
+
+// CIR: %[[COMPLEX:.*]] = cir.alloca !cir.complex<!cir.float>, !cir.ptr<!cir.complex<!cir.float>>, ["a"]
+// CIR: %[[RESULT:.*]] = cir.alloca !cir.complex<!cir.float>, !cir.ptr<!cir.complex<!cir.float>>, ["b", init]
+// CIR: %[[TMP:.*]] = cir.load{{.*}} %[[COMPLEX]] : !cir.ptr<!cir.complex<!cir.float>>, !cir.complex<!cir.float>
+// CIR: %[[REAL:.*]] = cir.complex.real %[[TMP]] : !cir.complex<!cir.float> -> !cir.float
+// CIR: %[[IMAG:.*]] = cir.complex.imag %[[TMP]] : !cir.complex<!cir.float> -> !cir.float
+// CIR: %[[IMAG_MINUS:.*]] = cir.unary(minus, %[[IMAG]]) : !cir.float, !cir.float
+// CIR: %[[RESULT_VAL:.*]] = cir.complex.create %[[REAL]], %[[IMAG_MINUS]] : !cir.float -> !cir.complex<!cir.float>
+// CIR: cir.store{{.*}} %[[RESULT_VAL]], %[[RESULT]] : !cir.complex<!cir.float>, !cir.ptr<!cir.complex<!cir.float>>
+
+// LLVM: %[[COMPLEX:.*]] = alloca { float, float }, i64 1, align 4
+// LLVM: %[[RESULT:.*]] = alloca { float, float }, i64 1, align 4
+// LLVM: %[[TMP:.*]] = load { float, float }, ptr %[[COMPLEX]], align 4
+// LLVM: %[[REAL:.*]] = extractvalue { float, float } %[[TMP]], 0
+// LLVM: %[[IMAG:.*]] = extractvalue { float, float } %[[TMP]], 1
+// LLVM: %[[IMAG_MINUS:.*]] = fneg float %[[IMAG]]
+// LLVM: %[[RESULT_TMP:.*]] = insertvalue { float, float } {{.*}}, float %[[REAL]], 0
+// LLVM: %[[RESULT_VAL:.*]] = insertvalue { float, float } %[[RESULT_TMP]], float %[[IMAG_MINUS]], 1
+// LLVM: store { float, float } %[[RESULT_VAL]], ptr %[[RESULT]], align 4
+
+// OGCG: %[[COMPLEX:.*]] = alloca { float, float }, align 4
+// OGCG: %[[RESULT:.*]] = alloca { float, float }, align 4
+// OGCG: %[[A_REAL_PTR:.*]] = getelementptr inbounds nuw { float, float }, ptr %[[COMPLEX]], i32 0, i32 0
+// OGCG: %[[A_REAL:.*]] = load float, ptr %[[A_REAL_PTR]], align 4
+// OGCG: %[[A_IMAG_PTR:.*]] = getelementptr inbounds nuw { float, float }, ptr %[[COMPLEX]], i32 0, i32 1
+// OGCG: %[[A_IMAG:.*]] = load float, ptr %[[A_IMAG_PTR]], align 4
+// OGCG: %[[A_IMAG_MINUS:.*]] = fneg float  %[[A_IMAG]]
+// OGCG: %[[RESULT_REAL_PTR:.*]] = getelementptr inbounds nuw { float, float }, ptr %[[RESULT]], i32 0, i32 0
+// OGCG: %[[RESULT_IMAG_PTR:.*]] = getelementptr inbounds nuw { float, float }, ptr %[[RESULT]], i32 0, i32 1
+// OGCG: store float %[[A_REAL]], ptr %[[RESULT_REAL_PTR]], align 4
+// OGCG: store float %[[A_IMAG_MINUS]], ptr %[[RESULT_IMAG_PTR]], align 4