164410324d
After D17993, with -fno-delete-null-pointer-checks we add the dereferenceable attribute to the `this` pointer. We have observed that one internal target which worked before fails even with -fno-delete-null-pointer-checks. Switching to dereferenceable_or_null fixes the problem. dereferenceable currently does not always respect NullPointerIsValid and may imply nonnull and lead to aggressive optimization. The optimization may be related to `CallBase::isReturnNonNull`, `Argument::hasNonNullAttr`, or `Value::getPointerDereferenceableBytes`. See D66664 and D66618 for some discussions. Reviewed By: bkramer, rsmith Differential Revision: https://reviews.llvm.org/D92297
21 lines
862 B
C++
21 lines
862 B
C++
// RUN: %clang_cc1 -S -emit-llvm -o - -triple=x86_64-linux-gnu %s | FileCheck %s -check-prefix=CHECK-YES
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// RUN: %clang_cc1 -S -emit-llvm -o - -fno-delete-null-pointer-checks -triple=x86_64-linux-gnu %s | FileCheck %s -check-prefix=CHECK-NO
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struct Struct {
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int many;
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int member;
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int fields;
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void ReturnsVoid();
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};
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void TestReturnsVoid(Struct &s) {
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s.ReturnsVoid();
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// CHECK-YES: call void @_ZN6Struct11ReturnsVoidEv(%struct.Struct* nonnull dereferenceable(12) %0)
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/// FIXME Use dereferenceable after dereferenceable respects NullPointerIsValid.
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// CHECK-NO: call void @_ZN6Struct11ReturnsVoidEv(%struct.Struct* dereferenceable_or_null(12) %0)
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}
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// CHECK-YES: declare void @_ZN6Struct11ReturnsVoidEv(%struct.Struct* nonnull dereferenceable(12))
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// CHECK-NO: declare void @_ZN6Struct11ReturnsVoidEv(%struct.Struct* dereferenceable_or_null(12))
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