[CIR] Implement CXXScalarValueInitExpr for ComplexType (llvm#147143)

Implement CXXScalarValueInitExpr support for ComplexType

llvm#141365

Author: AmrDeveloper

clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp

@@ -47,6 +47,7 @@ class ComplexExprEmitter : public StmtVisitor<ComplexExprEmitter, mlir::Value> {
   mlir::Value VisitCallExpr(const CallExpr *e);
   mlir::Value VisitCastExpr(CastExpr *e);
   mlir::Value VisitChooseExpr(ChooseExpr *e);
+  mlir::Value VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *e);
   mlir::Value VisitDeclRefExpr(DeclRefExpr *e);
   mlir::Value VisitGenericSelectionExpr(GenericSelectionExpr *e);
   mlir::Value VisitImplicitCastExpr(ImplicitCastExpr *e);
@@ -201,6 +202,13 @@ mlir::Value ComplexExprEmitter::VisitChooseExpr(ChooseExpr *e) {
   return Visit(e->getChosenSubExpr());
 }
 
+mlir::Value
+ComplexExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *e) {
+  mlir::Location loc = cgf.getLoc(e->getExprLoc());
+  mlir::Type complexTy = cgf.convertType(e->getType());
+  return builder.getNullValue(complexTy, loc);
+}
+
 mlir::Value ComplexExprEmitter::VisitDeclRefExpr(DeclRefExpr *e) {
   if (CIRGenFunction::ConstantEmission constant = cgf.tryEmitAsConstant(e))
     return emitConstant(constant, e);

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp

@@ -1044,10 +1044,19 @@ mlir::LogicalResult CIRToLLVMConstantOpLowering::matchAndRewrite(
                                                getTypeConverter()));
     return mlir::success();
   } else if (auto complexTy = mlir::dyn_cast<cir::ComplexType>(op.getType())) {
-    auto complexAttr = mlir::cast<cir::ConstComplexAttr>(op.getValue());
     mlir::Type complexElemTy = complexTy.getElementType();
     mlir::Type complexElemLLVMTy = typeConverter->convertType(complexElemTy);
 
+    if (auto zeroInitAttr = mlir::dyn_cast<cir::ZeroAttr>(op.getValue())) {
+      mlir::TypedAttr zeroAttr = rewriter.getZeroAttr(complexElemLLVMTy);
+      mlir::ArrayAttr array = rewriter.getArrayAttr({zeroAttr, zeroAttr});
+      rewriter.replaceOpWithNewOp<mlir::LLVM::ConstantOp>(
+          op, getTypeConverter()->convertType(op.getType()), array);
+      return mlir::success();
+    }
+
+    auto complexAttr = mlir::cast<cir::ConstComplexAttr>(op.getValue());
+
     mlir::Attribute components[2];
     if (mlir::isa<cir::IntType>(complexElemTy)) {
       components[0] = rewriter.getIntegerAttr(

clang/test/CIR/CodeGen/complex.cpp

@@ -717,6 +717,24 @@ void foo27(bool cond, int _Complex a, int _Complex b) {
 // OGCG:  store i32 %[[REAL]], ptr %[[RESULT_REAL_PTR]], align 4
 // OGCG:  store i32 %[[IMAG]], ptr %[[RESULT_IMAG_PTR]], align 4
 
+void foo28() {
+  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.zero : !cir.complex<!s32i>
+// CIR: cir.store align(4) %[[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
+
+// OGCG: %[[INIT:.*]] = alloca { i32, i32 }, align 4
+// OGCG: %[[INIT_REAL_PTR:.*]] = getelementptr inbounds nuw { i32, i32 }, ptr %[[INIT]], i32 0, i32 0
+// OGCG: %[[INIT_IMAG_PTR:.*]] = getelementptr inbounds nuw { i32, i32 }, ptr %[[INIT]], i32 0, i32 1
+// OGCG: store i32 0, ptr %[[INIT_REAL_PTR]], align 4
+// OGCG: store i32 0, ptr %[[INIT_IMAG_PTR]], align 4
+
 void foo29() {
   using IntComplex = int _Complex;
   int _Complex a = IntComplex{};