[CIR] Implement support for OffsetOfExpr #167726
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@llvm/pr-subscribers-clangir Author: Amr Hesham (AmrDeveloper) ChangesImplement support for the OffsetOfExpr Full diff: https://github.com/llvm/llvm-project/pull/167726.diff 2 Files Affected:
diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
index c1a36134d8942..c62e30d7e9c98 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
@@ -197,6 +197,8 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
return emitNullValue(e->getType(), cgf.getLoc(e->getSourceRange()));
}
+ mlir::Value VisitOffsetOfExpr(OffsetOfExpr *e);
+
mlir::Value VisitOpaqueValueExpr(OpaqueValueExpr *e) {
if (e->isGLValue())
return emitLoadOfLValue(cgf.getOrCreateOpaqueLValueMapping(e),
@@ -2164,6 +2166,21 @@ mlir::Value ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *e) {
return maybePromoteBoolResult(boolVal, cgf.convertType(e->getType()));
}
+mlir::Value ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *e) {
+ // Try folding the offsetof to a constant.
+ Expr::EvalResult evalResult;
+ if (e->EvaluateAsInt(evalResult, cgf.getContext())) {
+ mlir::Type type = cgf.convertType(e->getType());
+ llvm::APSInt value = evalResult.Val.getInt();
+ return builder.getConstAPInt(cgf.getLoc(e->getExprLoc()), type, value);
+ }
+
+ cgf.getCIRGenModule().errorNYI(
+ e->getSourceRange(),
+ "ScalarExprEmitter::VisitOffsetOfExpr Can't eval expr as int");
+ return {};
+}
+
mlir::Value ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *e) {
QualType promotionTy = getPromotionType(e->getSubExpr()->getType());
mlir::Value result = VisitRealImag(e, promotionTy);
diff --git a/clang/test/CIR/CodeGen/offset-of.cpp b/clang/test/CIR/CodeGen/offset-of.cpp
new file mode 100644
index 0000000000000..f62da9e6d9413
--- /dev/null
+++ b/clang/test/CIR/CodeGen/offset-of.cpp
@@ -0,0 +1,93 @@
+// 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 Struct {
+ int a;
+ float b;
+ double c;
+ bool d;
+};
+
+void offset_of_builtin() {
+ unsigned long a = __builtin_offsetof(Struct, a);
+ unsigned long b = __builtin_offsetof(Struct, b);
+ unsigned long c = __builtin_offsetof(Struct, c);
+ unsigned long d = __builtin_offsetof(Struct, d);
+}
+
+// CIR: %[[A_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["a", init]
+// CIR: %[[B_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["b", init]
+// CIR: %[[C_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["c", init]
+// CIR: %[[D_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["d", init]
+// CIR: %[[CONST_0:.*]] = cir.const #cir.int<0> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_0]], %[[A_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_4:.*]] = cir.const #cir.int<4> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_4]], %[[B_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_8:.*]] = cir.const #cir.int<8> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_8]], %[[C_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_16:.*]] = cir.const #cir.int<16> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_16]], %[[D_ADDR]] : !u64i, !cir.ptr<!u64i>
+
+// LLVM: %[[A_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[B_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[C_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[D_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: store i64 0, ptr %[[A_ADDR]], align 8
+// LLVM: store i64 4, ptr %[[B_ADDR]], align 8
+// LLVM: store i64 8, ptr %[[C_ADDR]], align 8
+// LLVM: store i64 16, ptr %[[D_ADDR]], align 8
+
+// OGCG: %[[A_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[B_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[C_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[D_ADDR:.*]] = alloca i64, align 8
+// OGCG: store i64 0, ptr %[[A_ADDR]], align 8
+// OGCG: store i64 4, ptr %[[B_ADDR]], align 8
+// OGCG: store i64 8, ptr %[[C_ADDR]], align 8
+// OGCG: store i64 16, ptr %[[D_ADDR]], align 8
+
+struct StructWithArray {
+ Struct array[4][4];
+};
+
+void offset_of_builtin_from_array_element() {
+ unsigned long a = __builtin_offsetof(StructWithArray, array[0][0].a);
+ unsigned long b = __builtin_offsetof(StructWithArray, array[1][1].b);
+ unsigned long c = __builtin_offsetof(StructWithArray, array[2][2].c);
+ unsigned long d = __builtin_offsetof(StructWithArray, array[3][3].d);
+}
+
+// CIR: %[[A_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["a", init]
+// CIR: %[[B_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["b", init]
+// CIR: %[[C_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["c", init]
+// CIR: %[[D_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["d", init]
+// CIR: %[[CONST_0:.*]] = cir.const #cir.int<0> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_0]], %[[A_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_124:.*]] = cir.const #cir.int<124> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_124]], %[[B_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_248:.*]] = cir.const #cir.int<248> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_248]], %[[C_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_376:.*]] = cir.const #cir.int<376> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_376]], %[[D_ADDR]] : !u64i, !cir.ptr<!u64i>
+
+// LLVM: %[[A_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[B_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[C_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[D_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: store i64 0, ptr %[[A_ADDR]], align 8
+// LLVM: store i64 124, ptr %[[B_ADDR]], align 8
+// LLVM: store i64 248, ptr %[[C_ADDR]], align 8
+// LLVM: store i64 376, ptr %[[D_ADDR]], align 8
+
+// OGCG: %[[A_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[B_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[C_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[D_ADDR:.*]] = alloca i64, align 8
+// OGCG: store i64 0, ptr %[[A_ADDR]], align 8
+// OGCG: store i64 124, ptr %[[B_ADDR]], align 8
+// OGCG: store i64 248, ptr %[[C_ADDR]], align 8
+// OGCG: store i64 376, ptr %[[D_ADDR]], align 8
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Member
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@llvm/pr-subscribers-clang Author: Amr Hesham (AmrDeveloper) ChangesImplement support for the OffsetOfExpr Full diff: https://github.com/llvm/llvm-project/pull/167726.diff 2 Files Affected:
diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
index c1a36134d8942..c62e30d7e9c98 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
@@ -197,6 +197,8 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
return emitNullValue(e->getType(), cgf.getLoc(e->getSourceRange()));
}
+ mlir::Value VisitOffsetOfExpr(OffsetOfExpr *e);
+
mlir::Value VisitOpaqueValueExpr(OpaqueValueExpr *e) {
if (e->isGLValue())
return emitLoadOfLValue(cgf.getOrCreateOpaqueLValueMapping(e),
@@ -2164,6 +2166,21 @@ mlir::Value ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *e) {
return maybePromoteBoolResult(boolVal, cgf.convertType(e->getType()));
}
+mlir::Value ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *e) {
+ // Try folding the offsetof to a constant.
+ Expr::EvalResult evalResult;
+ if (e->EvaluateAsInt(evalResult, cgf.getContext())) {
+ mlir::Type type = cgf.convertType(e->getType());
+ llvm::APSInt value = evalResult.Val.getInt();
+ return builder.getConstAPInt(cgf.getLoc(e->getExprLoc()), type, value);
+ }
+
+ cgf.getCIRGenModule().errorNYI(
+ e->getSourceRange(),
+ "ScalarExprEmitter::VisitOffsetOfExpr Can't eval expr as int");
+ return {};
+}
+
mlir::Value ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *e) {
QualType promotionTy = getPromotionType(e->getSubExpr()->getType());
mlir::Value result = VisitRealImag(e, promotionTy);
diff --git a/clang/test/CIR/CodeGen/offset-of.cpp b/clang/test/CIR/CodeGen/offset-of.cpp
new file mode 100644
index 0000000000000..f62da9e6d9413
--- /dev/null
+++ b/clang/test/CIR/CodeGen/offset-of.cpp
@@ -0,0 +1,93 @@
+// 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 Struct {
+ int a;
+ float b;
+ double c;
+ bool d;
+};
+
+void offset_of_builtin() {
+ unsigned long a = __builtin_offsetof(Struct, a);
+ unsigned long b = __builtin_offsetof(Struct, b);
+ unsigned long c = __builtin_offsetof(Struct, c);
+ unsigned long d = __builtin_offsetof(Struct, d);
+}
+
+// CIR: %[[A_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["a", init]
+// CIR: %[[B_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["b", init]
+// CIR: %[[C_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["c", init]
+// CIR: %[[D_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["d", init]
+// CIR: %[[CONST_0:.*]] = cir.const #cir.int<0> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_0]], %[[A_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_4:.*]] = cir.const #cir.int<4> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_4]], %[[B_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_8:.*]] = cir.const #cir.int<8> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_8]], %[[C_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_16:.*]] = cir.const #cir.int<16> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_16]], %[[D_ADDR]] : !u64i, !cir.ptr<!u64i>
+
+// LLVM: %[[A_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[B_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[C_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[D_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: store i64 0, ptr %[[A_ADDR]], align 8
+// LLVM: store i64 4, ptr %[[B_ADDR]], align 8
+// LLVM: store i64 8, ptr %[[C_ADDR]], align 8
+// LLVM: store i64 16, ptr %[[D_ADDR]], align 8
+
+// OGCG: %[[A_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[B_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[C_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[D_ADDR:.*]] = alloca i64, align 8
+// OGCG: store i64 0, ptr %[[A_ADDR]], align 8
+// OGCG: store i64 4, ptr %[[B_ADDR]], align 8
+// OGCG: store i64 8, ptr %[[C_ADDR]], align 8
+// OGCG: store i64 16, ptr %[[D_ADDR]], align 8
+
+struct StructWithArray {
+ Struct array[4][4];
+};
+
+void offset_of_builtin_from_array_element() {
+ unsigned long a = __builtin_offsetof(StructWithArray, array[0][0].a);
+ unsigned long b = __builtin_offsetof(StructWithArray, array[1][1].b);
+ unsigned long c = __builtin_offsetof(StructWithArray, array[2][2].c);
+ unsigned long d = __builtin_offsetof(StructWithArray, array[3][3].d);
+}
+
+// CIR: %[[A_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["a", init]
+// CIR: %[[B_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["b", init]
+// CIR: %[[C_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["c", init]
+// CIR: %[[D_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["d", init]
+// CIR: %[[CONST_0:.*]] = cir.const #cir.int<0> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_0]], %[[A_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_124:.*]] = cir.const #cir.int<124> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_124]], %[[B_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_248:.*]] = cir.const #cir.int<248> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_248]], %[[C_ADDR]] : !u64i, !cir.ptr<!u64i>
+// CIR: %[[CONST_376:.*]] = cir.const #cir.int<376> : !u64i
+// CIR: cir.store {{.*}} %[[CONST_376]], %[[D_ADDR]] : !u64i, !cir.ptr<!u64i>
+
+// LLVM: %[[A_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[B_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[C_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: %[[D_ADDR:.*]] = alloca i64, i64 1, align 8
+// LLVM: store i64 0, ptr %[[A_ADDR]], align 8
+// LLVM: store i64 124, ptr %[[B_ADDR]], align 8
+// LLVM: store i64 248, ptr %[[C_ADDR]], align 8
+// LLVM: store i64 376, ptr %[[D_ADDR]], align 8
+
+// OGCG: %[[A_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[B_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[C_ADDR:.*]] = alloca i64, align 8
+// OGCG: %[[D_ADDR:.*]] = alloca i64, align 8
+// OGCG: store i64 0, ptr %[[A_ADDR]], align 8
+// OGCG: store i64 124, ptr %[[B_ADDR]], align 8
+// OGCG: store i64 248, ptr %[[C_ADDR]], align 8
+// OGCG: store i64 376, ptr %[[D_ADDR]], align 8
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bcardosolopes
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Nov 14, 2025
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Implement support for the OffsetOfExpr