[CIR] Backport functional cast to ComplexType (llvm#1737)

Backport functional cast to ComplexType

Author: AmrDeveloper

clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp

@@ -419,12 +419,12 @@ mlir::Value ComplexExprEmitter::emitCast(CastKind CK, Expr *Op,
 
   // Atomic to non-atomic casts may be more than a no-op for some platforms and
   // for some types.
+  case CK_NoOp:
   case CK_LValueToRValue:
     return Visit(Op);
 
   case CK_AtomicToNonAtomic:
   case CK_NonAtomicToAtomic:
-  case CK_NoOp:
   case CK_UserDefinedConversion:
     llvm_unreachable("NYI");
 

clang/test/CIR/CodeGen/complex.cpp

@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -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 -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
+
+void complex_functional_cast() {
+  using IntComplex = int _Complex;
+  int _Complex a = IntComplex{};
+}
+
+// CIR: %[[INIT:.*]] = cir.alloca !cir.complex<!s32i>, !cir.ptr<!cir.complex<!s32i>>, ["a", init]
+// CIR: %[[COMPLEX:.*]] = cir.const #cir.complex<#cir.int<0> : !s32i, #cir.int<0> : !s32i> : !cir.complex<!s32i>
+// CIR: cir.store{{.*}} %[[COMPLEX]], %[[INIT]] : !cir.complex<!s32i>, !cir.ptr<!cir.complex<!s32i>>
+
+// LLVM: %[[INIT:.*]] = alloca { i32, i32 }, i64 1, align 4
+// LLVM: store { i32, i32 } zeroinitializer, ptr %[[INIT]], align 4