[CIR] Implement part of ConstantExpr support for ComplexType (#173102)

Implement part of the ConstantExpr support for the ComplexType

Author: AmrDeveloper

clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp

@@ -1,4 +1,5 @@
 #include "CIRGenBuilder.h"
+#include "CIRGenConstantEmitter.h"
 #include "CIRGenFunction.h"
 
 #include "clang/AST/StmtVisitor.h"
@@ -66,7 +67,12 @@ class ComplexExprEmitter : public StmtVisitor<ComplexExprEmitter, mlir::Value> {
 
   mlir::Value VisitExpr(Expr *e);
   mlir::Value VisitConstantExpr(ConstantExpr *e) {
-    cgf.cgm.errorNYI(e->getExprLoc(), "ComplexExprEmitter VisitConstantExpr");
+    if (mlir::Attribute result = ConstantEmitter(cgf).tryEmitConstantExpr(e))
+      return builder.getConstant(cgf.getLoc(e->getSourceRange()),
+                                 mlir::cast<mlir::TypedAttr>(result));
+
+    cgf.cgm.errorNYI(e->getExprLoc(),
+                     "ComplexExprEmitter VisitConstantExpr non constantexpr");
     return {};
   }
 

clang/test/CIR/CodeGen/constant-expr.cpp

@@ -0,0 +1,31 @@
+// RUN: %clang_cc1 -std=c++20 -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 -std=c++20 -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
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -Wno-unused-value -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=OGCG
+
+struct StructWithConstEval {
+  consteval int _Complex consteval_ret_complex() { return {1, 2}; }
+};
+
+void calling_consteval_methods() {
+  StructWithConstEval a;
+  int _Complex c = a.consteval_ret_complex();
+}
+
+// CIR: %[[A_ADDR:.*]] = cir.alloca !rec_StructWithConstEval, !cir.ptr<!rec_StructWithConstEval>, ["a"]
+// CIR: %[[C_ADDR:.*]] = cir.alloca !cir.complex<!s32i>, !cir.ptr<!cir.complex<!s32i>>, ["c", init]
+// CIR: %[[CONST_COMPLEX:.*]] = cir.const #cir.const_complex<#cir.int<1> : !s32i, #cir.int<2> : !s32i> : !cir.complex<!s32i>
+// CIR: cir.store {{.*}} %[[CONST_COMPLEX]], %[[C_ADDR]] : !cir.complex<!s32i>, !cir.ptr<!cir.complex<!s32i>>
+
+// LLVM: %[[A_ADDR:.*]] = alloca %struct.StructWithConstEval, i64 1, align 1
+// LLVM: %[[C_ADDR:.*]] = alloca { i32, i32 }, i64 1, align 4
+// LLVM: store { i32, i32 } { i32 1, i32 2 }, ptr %[[C_ADDR]], align 4
+
+// OGCG: %[[A_ADDR:.*]] = alloca %struct.StructWithConstEval, align 1
+// OGCG: %[[C_ADDR:.*]] = alloca { i32, i32 }, align 4
+// OGCG: %[[C_REAL_PTR:.*]] = getelementptr inbounds nuw { i32, i32 }, ptr %[[C_ADDR]], i32 0, i32 0
+// OGCG: %[[C_IMAG_PTR:.*]] = getelementptr inbounds nuw { i32, i32 }, ptr %[[C_ADDR]], i32 0, i32 1
+// OGCG: store i32 1, ptr %[[C_REAL_PTR]], align 4
+// OGCG: store i32 2, ptr %[[C_IMAG_PTR]], align 4