[CIR] Upstream support for data member comparison

clang/lib/CIR/Dialect/Transforms/TargetLowering/CIRCXXABI.h

@@ -53,6 +53,10 @@ class CIRCXXABI {
   lowerGetRuntimeMember(cir::GetRuntimeMemberOp op, mlir::Type loweredResultTy,
                         mlir::Value loweredAddr, mlir::Value loweredMember,
                         mlir::OpBuilder &builder) const = 0;
+
+  virtual mlir::Value lowerDataMemberCmp(cir::CmpOp op, mlir::Value loweredLhs,
+                                         mlir::Value loweredRhs,
+                                         mlir::OpBuilder &builder) const = 0;
 };
 
 /// Creates an Itanium-family ABI.

clang/lib/CIR/Dialect/Transforms/TargetLowering/CMakeLists.txt

@@ -17,4 +17,5 @@ add_clang_library(MLIRCIRTargetLowering
   MLIRDLTIDialect
   MLIRCIR
   MLIRCIRInterfaces
+  MLIRLLVMDialect
 )

clang/lib/CIR/Dialect/Transforms/TargetLowering/LowerItaniumCXXABI.cpp

@@ -47,6 +47,10 @@ class LowerItaniumCXXABI : public CIRCXXABI {
   lowerGetRuntimeMember(cir::GetRuntimeMemberOp op, mlir::Type loweredResultTy,
                         mlir::Value loweredAddr, mlir::Value loweredMember,
                         mlir::OpBuilder &builder) const override;
+
+  mlir::Value lowerDataMemberCmp(cir::CmpOp op, mlir::Value loweredLhs,
+                                 mlir::Value loweredRhs,
+                                 mlir::OpBuilder &builder) const override;
 };
 
 } // namespace
@@ -108,4 +112,17 @@ mlir::Operation *LowerItaniumCXXABI::lowerGetRuntimeMember(
                              cir::CastKind::bitcast, memberBytesPtr);
 }
 
+mlir::Value
+LowerItaniumCXXABI::lowerDataMemberCmp(cir::CmpOp op, mlir::Value loweredLhs,
+                                       mlir::Value loweredRhs,
+                                       mlir::OpBuilder &builder) const {
+  assert(op.getKind() == cir::CmpOpKind::eq ||
+         op.getKind() == cir::CmpOpKind::ne);
+  mlir::LLVM::ICmpPredicate kind = op.getKind() == cir::CmpOpKind::eq
+                                       ? mlir::LLVM::ICmpPredicate::eq
+                                       : mlir::LLVM::ICmpPredicate::ne;
+  return mlir::LLVM::ICmpOp::create(builder, op.getLoc(), kind, loweredLhs,
+                                    loweredRhs);
+}
+
 } // namespace cir

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

@@ -2559,8 +2559,17 @@ mlir::LogicalResult CIRToLLVMCmpOpLowering::matchAndRewrite(
     mlir::ConversionPatternRewriter &rewriter) const {
   mlir::Type type = cmpOp.getLhs().getType();
 
-  assert(!cir::MissingFeatures::dataMemberType());
   assert(!cir::MissingFeatures::methodType());
+  if (mlir::isa<cir::DataMemberType>(type)) {
+    assert(lowerMod && "lowering module is not available");
+
+    mlir::Value loweredResult;
+    loweredResult = lowerMod->getCXXABI().lowerDataMemberCmp(
+        cmpOp, adaptor.getLhs(), adaptor.getRhs(), rewriter);
+
+    rewriter.replaceOp(cmpOp, loweredResult);
+    return mlir::success();
+  }
 
   if (mlir::isa<cir::IntType, mlir::IntegerType>(type)) {
     bool isSigned = mlir::isa<cir::IntType>(type)

clang/test/CIR/CodeGen/pointer-to-data-member-cmp.cpp

@@ -0,0 +1,58 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++17 -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir --check-prefix=CIR %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++17 -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --input-file=%t-cir.ll --check-prefix=LLVM %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++17 -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll --check-prefix=OGCG %s
+
+struct Foo {
+  int a;
+};
+
+struct Bar {
+  int a;
+};
+
+bool eq(int Foo::*x, int Foo::*y) {
+  return x == y;
+}
+
+// CIR-LABEL: @_Z2eqM3FooiS0_
+//      CIR:   %[[#x:]] = cir.load{{.*}} %{{.+}} : !cir.ptr<!cir.data_member<!s32i in !rec_Foo>>, !cir.data_member<!s32i in !rec_Foo>
+// CIR-NEXT:   %[[#y:]] = cir.load{{.*}} %{{.+}} : !cir.ptr<!cir.data_member<!s32i in !rec_Foo>>, !cir.data_member<!s32i in !rec_Foo>
+// CIR-NEXT:   %{{.+}} = cir.cmp(eq, %[[#x]], %[[#y]]) : !cir.data_member<!s32i in !rec_Foo>, !cir.bool
+//      CIR: }
+
+// LLVM-LABEL: @_Z2eqM3FooiS0_
+//      LLVM:   %[[#x:]] = load i64, ptr %{{.+}}, align 8
+// LLVM-NEXT:   %[[#y:]] = load i64, ptr %{{.+}}, align 8
+// LLVM-NEXT:   %{{.+}} = icmp eq i64 %[[#x]], %[[#y]]
+//      LLVM: }
+
+// OGCG-LABEL: @_Z2eqM3FooiS0_
+//      OGCG:   %[[#x:]] = load i64, ptr %{{.+}}, align 8
+// OGCG-NEXT:   %[[#y:]] = load i64, ptr %{{.+}}, align 8
+// OGCG-NEXT:   %{{.+}} = icmp eq i64 %[[#x]], %[[#y]]
+//      OGCG: }
+
+bool ne(int Foo::*x, int Foo::*y) {
+  return x != y;
+}
+
+// CIR-LABEL: @_Z2neM3FooiS0_
+//      CIR:   %[[#x:]] = cir.load{{.*}} %{{.+}} : !cir.ptr<!cir.data_member<!s32i in !rec_Foo>>, !cir.data_member<!s32i in !rec_Foo>
+// CIR-NEXT:   %[[#y:]] = cir.load{{.*}} %{{.+}} : !cir.ptr<!cir.data_member<!s32i in !rec_Foo>>, !cir.data_member<!s32i in !rec_Foo>
+// CIR-NEXT:   %{{.+}} = cir.cmp(ne, %[[#x]], %[[#y]]) : !cir.data_member<!s32i in !rec_Foo>, !cir.bool
+//      CIR: }
+
+// LLVM-LABEL: @_Z2neM3FooiS0_
+//      LLVM:   %[[#x:]] = load i64, ptr %{{.+}}, align 8
+// LLVM-NEXT:   %[[#y:]] = load i64, ptr %{{.+}}, align 8
+// LLVM-NEXT:   %{{.+}} = icmp ne i64 %[[#x]], %[[#y]]
+//      LLVM: }
+
+// OGCG-LABEL: @_Z2neM3FooiS0_
+//      OGCG:   %[[#x:]] = load i64, ptr %{{.+}}, align 8
+// OGCG-NEXT:   %[[#y:]] = load i64, ptr %{{.+}}, align 8
+// OGCG-NEXT:   %{{.+}} = icmp ne i64 %[[#x]], %[[#y]]
+//      OGCG: }