[clang] [CIR] Upstream handling for member ptr function compare (PR #176029)
Andy Kaylor via cfe-commits
cfe-commits at lists.llvm.org
Wed Jan 14 12:25:20 PST 2026
https://github.com/andykaylor created https://github.com/llvm/llvm-project/pull/176029
This adds handling for compare expressions involving member pointer to functions.
>From 68dd618cd4814685c49aaea2ab4188c6d071bcbe Mon Sep 17 00:00:00 2001
From: Andy Kaylor <akaylor at nvidia.com>
Date: Wed, 14 Jan 2026 12:21:40 -0800
Subject: [PATCH] [CIR] Upstream handling for member ptr function compare
This adds handling for compare expressions involving member pointer to
functions.
---
.../CIR/Dialect/Transforms/CXXABILowering.cpp | 16 ++-
.../Transforms/TargetLowering/CIRCXXABI.h | 4 +
.../TargetLowering/LowerItaniumCXXABI.cpp | 51 ++++++++
.../CodeGen/pointer-to-member-func-cmp.cpp | 121 ++++++++++++++++++
4 files changed, 186 insertions(+), 6 deletions(-)
create mode 100644 clang/test/CIR/CodeGen/pointer-to-member-func-cmp.cpp
diff --git a/clang/lib/CIR/Dialect/Transforms/CXXABILowering.cpp b/clang/lib/CIR/Dialect/Transforms/CXXABILowering.cpp
index 145f8574893f4..dbe656ac011d8 100644
--- a/clang/lib/CIR/Dialect/Transforms/CXXABILowering.cpp
+++ b/clang/lib/CIR/Dialect/Transforms/CXXABILowering.cpp
@@ -159,12 +159,16 @@ mlir::LogicalResult CIRCmpOpABILowering::matchAndRewrite(
cir::CmpOp op, OpAdaptor adaptor,
mlir::ConversionPatternRewriter &rewriter) const {
mlir::Type type = op.getLhs().getType();
- assert((mlir::isa<cir::DataMemberType>(type)) &&
- "input to cmp in ABI lowering must be a data member");
-
- assert(!cir::MissingFeatures::methodType());
- mlir::Value loweredResult = lowerModule->getCXXABI().lowerDataMemberCmp(
- op, adaptor.getLhs(), adaptor.getRhs(), rewriter);
+ assert((mlir::isa<cir::DataMemberType, cir::MethodType>(type)) &&
+ "input to cmp in ABI lowering must be a data member or method");
+
+ mlir::Value loweredResult;
+ if (mlir::isa<cir::DataMemberType>(type))
+ loweredResult = lowerModule->getCXXABI().lowerDataMemberCmp(
+ op, adaptor.getLhs(), adaptor.getRhs(), rewriter);
+ else
+ loweredResult = lowerModule->getCXXABI().lowerMethodCmp(
+ op, adaptor.getLhs(), adaptor.getRhs(), rewriter);
rewriter.replaceOp(op, loweredResult);
return mlir::success();
diff --git a/clang/lib/CIR/Dialect/Transforms/TargetLowering/CIRCXXABI.h b/clang/lib/CIR/Dialect/Transforms/TargetLowering/CIRCXXABI.h
index 0dedfa7221f5f..f4d608cdbad03 100644
--- a/clang/lib/CIR/Dialect/Transforms/TargetLowering/CIRCXXABI.h
+++ b/clang/lib/CIR/Dialect/Transforms/TargetLowering/CIRCXXABI.h
@@ -81,6 +81,10 @@ class CIRCXXABI {
virtual mlir::Value lowerDataMemberCmp(cir::CmpOp op, mlir::Value loweredLhs,
mlir::Value loweredRhs,
mlir::OpBuilder &builder) const = 0;
+
+ virtual mlir::Value lowerMethodCmp(cir::CmpOp op, mlir::Value loweredLhs,
+ mlir::Value loweredRhs,
+ mlir::OpBuilder &builder) const = 0;
};
/// Creates an Itanium-family ABI.
diff --git a/clang/lib/CIR/Dialect/Transforms/TargetLowering/LowerItaniumCXXABI.cpp b/clang/lib/CIR/Dialect/Transforms/TargetLowering/LowerItaniumCXXABI.cpp
index d944fa3294684..0850368d62718 100644
--- a/clang/lib/CIR/Dialect/Transforms/TargetLowering/LowerItaniumCXXABI.cpp
+++ b/clang/lib/CIR/Dialect/Transforms/TargetLowering/LowerItaniumCXXABI.cpp
@@ -67,6 +67,10 @@ class LowerItaniumCXXABI : public CIRCXXABI {
mlir::Value lowerDataMemberCmp(cir::CmpOp op, mlir::Value loweredLhs,
mlir::Value loweredRhs,
mlir::OpBuilder &builder) const override;
+
+ mlir::Value lowerMethodCmp(cir::CmpOp op, mlir::Value loweredLhs,
+ mlir::Value loweredRhs,
+ mlir::OpBuilder &builder) const override;
};
} // namespace
@@ -249,4 +253,51 @@ LowerItaniumCXXABI::lowerDataMemberCmp(cir::CmpOp op, mlir::Value loweredLhs,
loweredRhs);
}
+mlir::Value LowerItaniumCXXABI::lowerMethodCmp(cir::CmpOp op,
+ mlir::Value loweredLhs,
+ mlir::Value loweredRhs,
+ mlir::OpBuilder &builder) const {
+ assert(op.getKind() == cir::CmpOpKind::eq ||
+ op.getKind() == cir::CmpOpKind::ne);
+
+ cir::IntType ptrdiffCIRTy = getPtrDiffCIRTy(lm);
+ mlir::Value ptrdiffZero = cir::ConstantOp::create(
+ builder, op.getLoc(), cir::IntAttr::get(ptrdiffCIRTy, 0));
+ mlir::Location loc = op.getLoc();
+
+ mlir::Value lhsPtrField =
+ cir::ExtractMemberOp::create(builder, loc, ptrdiffCIRTy, loweredLhs, 0);
+ mlir::Value rhsPtrField =
+ cir::ExtractMemberOp::create(builder, loc, ptrdiffCIRTy, loweredRhs, 0);
+ mlir::Value ptrCmp =
+ cir::CmpOp::create(builder, loc, op.getKind(), lhsPtrField, rhsPtrField);
+ mlir::Value ptrCmpToNull =
+ cir::CmpOp::create(builder, loc, op.getKind(), lhsPtrField, ptrdiffZero);
+
+ mlir::Value lhsAdjField =
+ cir::ExtractMemberOp::create(builder, loc, ptrdiffCIRTy, loweredLhs, 1);
+ mlir::Value rhsAdjField =
+ cir::ExtractMemberOp::create(builder, loc, ptrdiffCIRTy, loweredRhs, 1);
+ mlir::Value adjCmp =
+ cir::CmpOp::create(builder, loc, op.getKind(), lhsAdjField, rhsAdjField);
+
+ auto create_and = [&](mlir::Value lhs, mlir::Value rhs) {
+ return cir::BinOp::create(builder, loc, cir::BinOpKind::And, lhs, rhs);
+ };
+ auto create_or = [&](mlir::Value lhs, mlir::Value rhs) {
+ return cir::BinOp::create(builder, loc, cir::BinOpKind::Or, lhs, rhs);
+ };
+
+ mlir::Value result;
+ if (op.getKind() == cir::CmpOpKind::eq) {
+ // (lhs.ptr == null || lhs.adj == rhs.adj) && lhs.ptr == rhs.ptr
+ result = create_and(ptrCmp, create_or(ptrCmpToNull, adjCmp));
+ } else {
+ // (lhs.ptr != null && lhs.adj != rhs.adj) || lhs.ptr != rhs.ptr
+ result = create_or(ptrCmp, create_and(ptrCmpToNull, adjCmp));
+ }
+
+ return result;
+}
+
} // namespace cir
diff --git a/clang/test/CIR/CodeGen/pointer-to-member-func-cmp.cpp b/clang/test/CIR/CodeGen/pointer-to-member-func-cmp.cpp
new file mode 100644
index 0000000000000..f00d227e97fe7
--- /dev/null
+++ b/clang/test/CIR/CodeGen/pointer-to-member-func-cmp.cpp
@@ -0,0 +1,121 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++17 -fclangir -emit-cir -mmlir -mlir-print-ir-before=cir-cxxabi-lowering %s -o %t.cir 2> %t-before.cir
+// RUN: FileCheck --check-prefix=CIR-BEFORE --input-file=%t-before.cir %s
+// RUN: FileCheck --check-prefix=CIR-AFTER --input-file=%t.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 --check-prefix=OGCG --input-file=%t.ll %s
+
+struct Foo {
+ void m1(int);
+ virtual void m2(int);
+ virtual void m3(int);
+};
+
+bool cmp_eq(void (Foo::*lhs)(int), void (Foo::*rhs)(int)) {
+ return lhs == rhs;
+}
+
+// CIR-BEFORE: cir.func {{.*}} @_Z6cmp_eqM3FooFviES1_
+// CIR-BEFORE: %[[LHS:.*]] = cir.load{{.*}} %0 : !cir.ptr<!cir.method<!cir.func<(!s32i)> in !rec_Foo>>
+// CIR-BEFORE: %[[RHS:.*]] = cir.load{{.*}} %1 : !cir.ptr<!cir.method<!cir.func<(!s32i)> in !rec_Foo>>
+// CIR-BEFORE: %[[CMP:.*]] = cir.cmp(eq, %[[LHS]], %[[RHS]]) : !cir.method<!cir.func<(!s32i)> in !rec_Foo>, !cir.bool
+// CIR-BEFORE: cir.store %[[CMP]], %{{.*}} : !cir.bool, !cir.ptr<!cir.bool>
+
+// CIR-AFTER: @_Z6cmp_eqM3FooFviES1_
+// CIR-AFTER: %[[LHS:.*]] = cir.load{{.*}} %0 : !cir.ptr<!rec_anon_struct>, !rec_anon_struct
+// CIR-AFTER: %[[RHS:.*]] = cir.load{{.*}} %1 : !cir.ptr<!rec_anon_struct>, !rec_anon_struct
+// CIR-AFTER: %[[NULL:.*]] = cir.const #cir.int<0> : !s64i
+// CIR-AFTER: %[[LHS_PTR:.*]] = cir.extract_member %[[LHS]][0] : !rec_anon_struct -> !s64i
+// CIR-AFTER: %[[RHS_PTR:.*]] = cir.extract_member %[[RHS]][0] : !rec_anon_struct -> !s64i
+// CIR-AFTER: %[[PTR_CMP:.*]] = cir.cmp(eq, %[[LHS_PTR]], %[[RHS_PTR]]) : !s64i, !cir.bool
+// CIR-AFTER: %[[PTR_NULL:.*]] = cir.cmp(eq, %[[LHS_PTR]], %[[NULL]]) : !s64i, !cir.bool
+// CIR-AFTER: %[[LHS_ADJ:.*]] = cir.extract_member %[[LHS]][1] : !rec_anon_struct -> !s64i
+// CIR-AFTER: %[[RHS_ADJ:.*]] = cir.extract_member %[[RHS]][1] : !rec_anon_struct -> !s64i
+// CIR-AFTER: %[[ADJ_CMP:.*]] = cir.cmp(eq, %[[LHS_ADJ]], %[[RHS_ADJ]]) : !s64i, !cir.bool
+// CIR-AFTER: %[[TMP:.*]] = cir.binop(or, %[[PTR_NULL]], %[[ADJ_CMP]]) : !cir.bool
+// CIR-AFTER: %[[RESULT:.*]] = cir.binop(and, %[[PTR_CMP]], %[[TMP]]) : !cir.bool
+
+// LLVM: define {{.*}} i1 @_Z6cmp_eqM3FooFviES1_
+// LLVM: %[[LHS:.*]] = load { i64, i64 }, ptr %{{.+}}
+// LLVM: %[[RHS:.*]] = load { i64, i64 }, ptr %{{.+}}
+// LLVM: %[[LHS_PTR:.*]] = extractvalue { i64, i64 } %[[LHS]], 0
+// LLVM: %[[RHS_PTR:.*]] = extractvalue { i64, i64 } %[[RHS]], 0
+// LLVM: %[[PTR_CMP:.*]] = icmp eq i64 %[[LHS_PTR]], %[[RHS_PTR]]
+// LLVM: %[[PTR_NULL:.*]] = icmp eq i64 %[[LHS_PTR]], 0
+// LLVM: %[[LHS_ADJ:.*]] = extractvalue { i64, i64 } %[[LHS]], 1
+// LLVM: %[[RHS_ADJ:.*]] = extractvalue { i64, i64 } %[[RHS]], 1
+// LLVM: %[[ADJ_CMP:.*]] = icmp eq i64 %[[LHS_ADJ]], %[[RHS_ADJ]]
+// LLVM: %[[TMP:.*]] = or i1 %[[PTR_NULL]], %[[ADJ_CMP]]
+// LLVM: %[[RESULT:.*]] = and i1 %[[PTR_CMP]], %[[TMP]]
+
+// OGCG: define {{.*}} i1 @_Z6cmp_eqM3FooFviES1_
+// OGCG: %[[LHS_TMP:.*]] = alloca { i64, i64 }
+// OGCG: %[[RHS_TMP:.*]] = alloca { i64, i64 }
+// OGCG: %[[LHS_ADDR:.*]] = alloca { i64, i64 }
+// OGCG: %[[RHS_ADDR:.*]] = alloca { i64, i64 }
+// OGCG: %[[LHS:.*]] = load { i64, i64 }, ptr %[[LHS_ADDR]]
+// OGCG: %[[RHS:.*]] = load { i64, i64 }, ptr %[[RHS_ADDR]]
+// OGCG: %[[LHS_PTR:.*]] = extractvalue { i64, i64 } %[[LHS]], 0
+// OGCG: %[[RHS_PTR:.*]] = extractvalue { i64, i64 } %[[RHS]], 0
+// OGCG: %[[PTR_CMP:.*]] = icmp eq i64 %[[LHS_PTR]], %[[RHS_PTR]]
+// OGCG: %[[PTR_NULL:.*]] = icmp eq i64 %[[LHS_PTR]], 0
+// OGCG: %[[LHS_ADJ:.*]] = extractvalue { i64, i64 } %[[LHS]], 1
+// OGCG: %[[RHS_ADJ:.*]] = extractvalue { i64, i64 } %[[RHS]], 1
+// OGCG: %[[ADJ_CMP:.*]] = icmp eq i64 %[[LHS_ADJ]], %[[RHS_ADJ]]
+// OGCG: %[[TMP:.*]] = or i1 %[[PTR_NULL]], %[[ADJ_CMP]]
+// OGCG: %[[RESULT:.*]] = and i1 %[[PTR_CMP]], %[[TMP]]
+
+bool cmp_ne(void (Foo::*lhs)(int), void (Foo::*rhs)(int)) {
+ return lhs != rhs;
+}
+
+// CIR-BEFORE: cir.func {{.*}} @_Z6cmp_neM3FooFviES1_
+// CIR-BEFORE: %[[LHS:.*]] = cir.load{{.*}} %0 : !cir.ptr<!cir.method<!cir.func<(!s32i)> in !rec_Foo>>
+// CIR-BEFORE: %[[RHS:.*]] = cir.load{{.*}} %1 : !cir.ptr<!cir.method<!cir.func<(!s32i)> in !rec_Foo>>
+// CIR-BEFORE: %[[CMP:.*]] = cir.cmp(ne, %[[LHS]], %[[RHS]]) : !cir.method<!cir.func<(!s32i)> in !rec_Foo>, !cir.bool
+// CIR-BEFORE: cir.store %[[CMP]], %{{.*}} : !cir.bool, !cir.ptr<!cir.bool>
+
+// CIR-AFTER: cir.func {{.*}} @_Z6cmp_neM3FooFviES1_
+// CIR-AFTER: %[[LHS:.*]] = cir.load{{.*}} %0 : !cir.ptr<!rec_anon_struct>, !rec_anon_struct
+// CIR-AFTER: %[[RHS:.*]] = cir.load{{.*}} %1 : !cir.ptr<!rec_anon_struct>, !rec_anon_struct
+// CIR-AFTER: %[[NULL:.*]] = cir.const #cir.int<0> : !s64i
+// CIR-AFTER: %[[LHS_PTR:.*]] = cir.extract_member %[[LHS]][0] : !rec_anon_struct -> !s64i
+// CIR-AFTER: %[[RHS_PTR:.*]] = cir.extract_member %[[RHS]][0] : !rec_anon_struct -> !s64i
+// CIR-AFTER: %[[PTR_CMP:.*]] = cir.cmp(ne, %[[LHS_PTR]], %[[RHS_PTR]]) : !s64i, !cir.bool
+// CIR-AFTER: %[[PTR_NULL:.*]] = cir.cmp(ne, %[[LHS_PTR]], %[[NULL]]) : !s64i, !cir.bool
+// CIR-AFTER: %[[LHS_ADJ:.*]] = cir.extract_member %[[LHS]][1] : !rec_anon_struct -> !s64i
+// CIR-AFTER: %[[RHS_ADJ:.*]] = cir.extract_member %[[RHS]][1] : !rec_anon_struct -> !s64i
+// CIR-AFTER: %[[ADJ_CMP:.*]] = cir.cmp(ne, %[[LHS_ADJ]], %[[RHS_ADJ]]) : !s64i, !cir.bool
+// CIR-AFTER: %[[TMP:.*]] = cir.binop(and, %[[PTR_NULL]], %[[ADJ_CMP]]) : !cir.bool
+// CIR-AFTER: %[[RESULT:.*]] = cir.binop(or, %[[PTR_CMP]], %[[TMP]]) : !cir.bool
+
+// LLVM: define {{.*}} i1 @_Z6cmp_neM3FooFviES1_
+// LLVM: %[[LHS:.*]] = load { i64, i64 }, ptr %{{.*}}
+// LLVM: %[[RHS:.*]] = load { i64, i64 }, ptr %{{.*}}
+// LLVM: %[[LHS_PTR:.*]] = extractvalue { i64, i64 } %[[LHS]], 0
+// LLVM: %[[RHS_PTR:.*]] = extractvalue { i64, i64 } %[[RHS]], 0
+// LLVM: %[[PTR_CMP:.*]] = icmp ne i64 %[[LHS_PTR]], %[[RHS_PTR]]
+// LLVM: %[[PTR_NULL:.*]] = icmp ne i64 %[[LHS_PTR]], 0
+// LLVM: %[[LHS_ADJ:.*]] = extractvalue { i64, i64 } %[[LHS]], 1
+// LLVM: %[[RHS_ADJ:.*]] = extractvalue { i64, i64 } %[[RHS]], 1
+// LLVM: %[[ADJ_CMP:.*]] = icmp ne i64 %[[LHS_ADJ]], %[[RHS_ADJ]]
+// LLVM: %[[TMP:.*]] = and i1 %[[PTR_NULL]], %[[ADJ_CMP]]
+// LLVM: %[[RESULT:.*]] = or i1 %[[PTR_CMP]], %[[TMP]]
+
+// OGCG: define {{.*}} i1 @_Z6cmp_neM3FooFviES1_
+// OGCG: %[[LHS_TMP:.*]] = alloca { i64, i64 }
+// OGCG: %[[RHS_TMP:.*]] = alloca { i64, i64 }
+// OGCG: %[[LHS_ADDR:.*]] = alloca { i64, i64 }
+// OGCG: %[[RHS_ADDR:.*]] = alloca { i64, i64 }
+// OGCG: %[[LHS:.*]] = load { i64, i64 }, ptr %[[LHS_ADDR]]
+// OGCG: %[[RHS:.*]] = load { i64, i64 }, ptr %[[RHS_ADDR]]
+// OGCG: %[[LHS_PTR:.*]] = extractvalue { i64, i64 } %[[LHS]], 0
+// OGCG: %[[RHS_PTR:.*]] = extractvalue { i64, i64 } %[[RHS]], 0
+// OGCG: %[[PTR_CMP:.*]] = icmp ne i64 %[[LHS_PTR]], %[[RHS_PTR]]
+// OGCG: %[[PTR_NULL:.*]] = icmp ne i64 %[[LHS_PTR]], 0
+// OGCG: %[[LHS_ADJ:.*]] = extractvalue { i64, i64 } %[[LHS]], 1
+// OGCG: %[[RHS_ADJ:.*]] = extractvalue { i64, i64 } %[[RHS]], 1
+// OGCG: %[[ADJ_CMP:.*]] = icmp ne i64 %[[LHS_ADJ]], %[[RHS_ADJ]]
+// OGCG: %[[TMP:.*]] = and i1 %[[PTR_NULL]], %[[ADJ_CMP]]
+// OGCG: %[[RESULT:.*]] = or i1 %[[PTR_CMP]], %[[TMP]]
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