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[CIR][Lowering] Enabled VAArg lowering for cir::PointerType #1762

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Merged
merged 1 commit into from
Jul 28, 2025
Merged

[CIR][Lowering] Enabled VAArg lowering for cir::PointerType #1762

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3 changes: 2 additions & 1 deletion clang/lib/CIR/Dialect/Transforms/TargetLowering/Targets/LoweringPrepareX86CXXABI.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -91,7 +91,8 @@ mlir::Value LoweringPrepareX86CXXABI::lowerVAArgX86_64(
// Let's hope LLVM's va_arg instruction can take care of it.
// Remove this when X86_64ABIInfo::classify can take care of every type.
if (!mlir::isa<VoidType, IntType, SingleType, DoubleType, BoolType,
cir::RecordType, LongDoubleType>(op.getType()))
cir::RecordType, LongDoubleType, cir::PointerType>(
op.getType()))
return nullptr;

// Assume that va_list type is correct; should be pointer to LLVM type:
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60 changes: 60 additions & 0 deletions clang/test/CIR/Lowering/var-arg-x86_64.c
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Original file line number Diff line number Diff line change
Expand Up @@ -125,3 +125,63 @@ long double f2(int n, ...) {
// CIR: [[CAST_ALIGNED_VALUE:%.+]] = cir.load [[CAST_ALIGNED]]
// CIR: cir.store{{.*}} [[CAST_ALIGNED_VALUE]], [[RES]]
// CIR. cir.via.end

const char *f3(va_list args) {
return va_arg(args, const char *);
}

// CHECK: define{{.*}} @f3
// CHECK: [[VA_LIST_ALLOCA:%.+]] = alloca ptr
// ...
// CHECK: [[VA_LIST:%.+]] = load {{.*}} [[VA_LIST_ALLOCA]]
// CHECK: [[OFFSET_PTR:%.+]] = getelementptr {{.*}} [[VA_LIST]], i32 0, i32 0
// CHECK: [[OFFSET:%.+]] = load {{.*}}, ptr [[OFFSET_PTR]]
// CHECK: [[CMP:%.+]] = icmp ule i32 [[OFFSET]], 40
// CHECK: br i1 [[CMP]], label %[[THEN_BB:.+]], label %[[ELSE_BB:.+]]
//
// CHECK: [[THEN_BB]]:
// ...
// CHECK: [[NEW_OFFSET:%.+]] = add i32 [[OFFSET]], 8
// CHECK: store i32 [[NEW_OFFSET]], ptr [[OFFSET_PTR]]
// CHECK: br label %[[CONT_BB:.+]]
//
// CHECK: [[ELSE_BB]]:
// ...
// CHECK: [[OVERFLOW_ARG_AREA_ADDR:%.+]] = getelementptr {{.*}} [[VA_LIST]], i32 0, i32 2
// CHECK: [[OVERFLOW_ARG_AREA:%.+]] = load ptr, ptr [[OVERFLOW_ARG_AREA_ADDR]]
// CHECK: [[OVERFLOW_ARG_AREA_OFFSET:%.+]] = getelementptr {{.*}} [[OVERFLOW_ARG_AREA]], i64 8
// CHECK: store ptr [[OVERFLOW_ARG_AREA_OFFSET]], ptr [[OVERFLOW_ARG_AREA_ADDR]]
// CHECK: br label %[[CONT_BB]]
//
// CHECK: [[CONT_BB]]:
// ...
// CHECK: ret

// CIR-LABEL: cir.func dso_local @f3(
// CIR: %[[VALIST_VAR:.*]] = cir.alloca !cir.ptr<!rec___va_list_tag>, !cir.ptr<!cir.ptr<!rec___va_list_tag>>, ["args", init] {alignment = 8 : i64}
// CIR: %[[VALIST:.*]] = cir.load align(8) %[[VALIST_VAR]] : !cir.ptr<!cir.ptr<!rec___va_list_tag>>, !cir.ptr<!rec___va_list_tag>
// CIR: %[[GP_OFFSET_PTR:.*]] = cir.get_member %[[VALIST]][0] {name = "gp_offset"} : !cir.ptr<!rec___va_list_tag> -> !cir.ptr<!u32i>
// CIR: %[[GP_OFFSET:.*]] = cir.load %[[GP_OFFSET_PTR]] : !cir.ptr<!u32i>, !u32i
// CIR: %[[VAL_6:.*]] = cir.const #cir.int<40> : !u32i
// CIR: %[[VAL_7:.*]] = cir.cmp(le, %[[GP_OFFSET]], %[[VAL_6]]) : !u32i, !cir.bool
// CIR: cir.brcond %[[VAL_7]]

// CIR: %[[REG_SAVE_AREA_PTR:.*]] = cir.get_member %[[VALIST]][3] {name = "reg_save_area"} : !cir.ptr<!rec___va_list_tag> -> !cir.ptr<!cir.ptr<!void>>
// CIR: %[[REG_SAVE_AREA:.*]] = cir.load %[[REG_SAVE_AREA_PTR]] : !cir.ptr<!cir.ptr<!void>>, !cir.ptr<!void>
// CIR: %[[CUR_REG_SAVE_AREA:.*]] = cir.ptr_stride(%[[REG_SAVE_AREA]] : !cir.ptr<!void>, %[[GP_OFFSET]] : !u32i), !cir.ptr<!void>
// CIR: %[[VAL_11:.*]] = cir.const #cir.int<8> : !u32i
// CIR: %[[NEW_REG_SAVE_AREA:.*]] = cir.binop(add, %[[GP_OFFSET]], %[[VAL_11]]) : !u32i
// CIR: cir.store %[[NEW_REG_SAVE_AREA]], %[[GP_OFFSET_PTR]] : !u32i, !cir.ptr<!u32i>
// CIR: cir.br ^[[CONT_BB:.*]](%[[CUR_REG_SAVE_AREA]] : !cir.ptr<!void>)

// CIR: %[[OVERFLOW_ARG_AREA_PTR:.*]] = cir.get_member %[[VALIST]][2] {name = "overflow_arg_area"} : !cir.ptr<!rec___va_list_tag> -> !cir.ptr<!cir.ptr<!void>>
// CIR: %[[OVERFLOW_ARG_AREA:.*]] = cir.load %[[OVERFLOW_ARG_AREA_PTR]] : !cir.ptr<!cir.ptr<!void>>, !cir.ptr<!void>
// CIR: %[[VAL_15:.*]] = cir.const #cir.int<8> : !s32i
// CIR: %[[CUR_OVERFLOW_ARG_AREA:.*]] = cir.cast(bitcast, %[[OVERFLOW_ARG_AREA]] : !cir.ptr<!void>), !cir.ptr<!s8i>
// CIR: %[[NEW_OVERFLOW_ARG_AREA:.*]] = cir.ptr_stride(%[[CUR_OVERFLOW_ARG_AREA]] : !cir.ptr<!s8i>, %[[VAL_15]] : !s32i), !cir.ptr<!s8i>
// CIR: %[[VAL_18:.*]] = cir.cast(bitcast, %[[OVERFLOW_ARG_AREA_PTR]] : !cir.ptr<!cir.ptr<!void>>), !cir.ptr<!cir.ptr<!s8i>>
// CIR: cir.store %[[NEW_OVERFLOW_ARG_AREA]], %[[VAL_18]] : !cir.ptr<!s8i>, !cir.ptr<!cir.ptr<!s8i>>
// CIR: cir.br ^[[CONT_BB]](%[[OVERFLOW_ARG_AREA]] : !cir.ptr<!void>)

// ...
// CIR: cir.return
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