[llvm] r354051 - Recommit Optional specialization for trivially copyable types

Hans Wennborg via llvm-commits llvm-commits at lists.llvm.org
Fri Feb 15 04:59:54 PST 2019


This fixed the Chromium build, and it also seems to have helped the
clang-cmake-x86_64-avx2-linux bot ("ninja check 1" is green on
http://lab.llvm.org:8011/builders/clang-cmake-x86_64-avx2-linux/builds/8318)
so I'll let the revert stay in.

On Fri, Feb 15, 2019 at 1:21 PM Hans Wennborg <hans at chromium.org> wrote:
>
> I've speculatively reverted this (and r354055) in r354126. Because I
> suspect this caused Clang to get miscompiled with GCC on Ubuntu 14.04
> breaking the Chromium build
> (https://bugs.chromium.org/p/chromium/issues/detail?id=932277).
>
> I'd like to keep the revert in for an hour to see if it makes any
> difference. We can see if that also affects the
> clang-cmake-x86_64-avx2-linux bot.
>
> Thanks,
> Hans
>
> On Fri, Feb 15, 2019 at 2:22 AM via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
> >
> > Hi Serge,
> >
> > I'm not sure how/why, but it seems your commit is causing a test failure on one of the bots:
> >
> > http://lab.llvm.org:8011/builders/clang-cmake-x86_64-avx2-linux/builds/8308
> >
> > ******************** TEST 'LLVM :: ThinLTO/X86/funcimport.ll' FAILED ********************
> > Script:
> > --
> > : 'RUN: at line 2';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/opt -module-summary /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/llvm/test/ThinLTO/X86/funcimport.ll -o /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp.bc
> > : 'RUN: at line 3';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/opt -module-summary /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/llvm/test/ThinLTO/X86/Inputs/funcimport.ll -o /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp2.bc
> > : 'RUN: at line 4';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-lto -thinlto-action=thinlink -o /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp3.bc /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp.bc /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp2.bc
> > : 'RUN: at line 6';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-lto -thinlto-index-stats /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp3.bc | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/FileCheck /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/llvm/test/ThinLTO/X86/funcimport.ll -check-prefix=STATS
> > : 'RUN: at line 11';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-lto -thinlto-action=promote /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp.bc -thinlto-index=/home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp3.bc -o - | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-dis -o - | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/FileCheck /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/llvm/test/ThinLTO/X86/funcimport.ll --check-prefix=EXPORTSTATIC
> > : 'RUN: at line 24';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-lto -thinlto-action=import /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp2.bc -thinlto-index=/home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp3.bc -o - | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-dis -o - | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/FileCheck /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/llvm/test/ThinLTO/X86/funcimport.ll --check-prefix=IMPORTGLOB1
> > : 'RUN: at line 35';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-lto -thinlto-action=optimize /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp2.bc -o - | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-dis -o - | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/FileCheck /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/llvm/test/ThinLTO/X86/funcimport.ll --check-prefix=OPTIMIZED
> > : 'RUN: at line 39';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-lto -thinlto-action=codegen /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp2.bc -o - | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-nm -o - | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/FileCheck /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/llvm/test/ThinLTO/X86/funcimport.ll --check-prefix=CODEGEN
> > : 'RUN: at line 43';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-lto -thinlto-action=run /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp2.bc  /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp.bc  -exported-symbol=_main
> > : 'RUN: at line 44';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-nm -o - < /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp.bc.thinlto.o | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/FileCheck /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/llvm/test/ThinLTO/X86/funcimport.ll --check-prefix=ALL
> > : 'RUN: at line 45';   /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/llvm-nm -o - < /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/test/ThinLTO/X86/Output/funcimport.ll.tmp2.bc.thinlto.o | /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/stage1/bin/FileCheck /home/ssglocal/clang-cmake-x86_64-avx2-linux/clang-cmake-x86_64-avx2-linux/llvm/test/ThinLTO/X86/funcimport.ll --check-prefix=ALL2
> > --
> > Exit Code: 1
> >
> > Command Output (stderr):
> > --
> > LLVM ERROR: 32-bit absolute addressing is not supported in 64-bit mode
> >
> > --
> >
> > Can you please take a look? We hit this on our internal linux build bot which is also running gcc 5.4 on Ubuntu 16.04.5.
> >
> > Douglas Yung
> >
> > -----Original Message-----
> > From: llvm-commits <llvm-commits-bounces at lists.llvm.org> On Behalf Of Serge Guelton via llvm-commits
> > Sent: Thursday, February 14, 2019 11:17
> > To: llvm-commits at lists.llvm.org
> > Subject: [llvm] r354051 - Recommit Optional specialization for trivially copyable types
> >
> > Author: serge_sans_paille
> > Date: Thu Feb 14 11:17:00 2019
> > New Revision: 354051
> >
> > URL: http://llvm.org/viewvc/llvm-project?rev=354051&view=rev
> > Log:
> > Recommit Optional specialization for trivially copyable types
> >
> > Unfortunately the original code gets misscompiled by GCC (at least 8.1), this is a tentative workaround using std::memcpy instead of inplace new for trivially copyable types. I'll revert if it breaks.
> >
> > Original revision: https://reviews.llvm.org/D57097
> >
> > Modified:
> >     llvm/trunk/include/llvm/ADT/Optional.h
> >     llvm/trunk/unittests/ADT/OptionalTest.cpp
> >
> > Modified: llvm/trunk/include/llvm/ADT/Optional.h
> > URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/Optional.h?rev=354051&r1=354050&r2=354051&view=diff
> > ==============================================================================
> > --- llvm/trunk/include/llvm/ADT/Optional.h (original)
> > +++ llvm/trunk/include/llvm/ADT/Optional.h Thu Feb 14 11:17:00 2019
> > @@ -21,6 +21,7 @@
> >  #include "llvm/Support/type_traits.h"
> >  #include <algorithm>
> >  #include <cassert>
> > +#include <cstring>
> >  #include <new>
> >  #include <utility>
> >
> > @@ -109,6 +110,48 @@ template <typename T, bool = is_triviall
> >    }
> >  };
> >
> > +template <typename T> struct OptionalStorage<T, true> {
> > +  AlignedCharArrayUnion<T> storage;
> > +  bool hasVal = false;
> > +
> > +  OptionalStorage() = default;
> > +
> > +  OptionalStorage(const T &y) : hasVal(true) { new (storage.buffer)
> > + T(y); }  OptionalStorage(const OptionalStorage &O) = default;
> > + OptionalStorage(T &&y) : hasVal(true) {
> > +    std::memcpy(storage.buffer, reinterpret_cast<char*>(&y),
> > + sizeof(T));  }
> > +
> > +  OptionalStorage(OptionalStorage &&O) = default;
> > +
> > +  OptionalStorage &operator=(T &&y) {
> > +    hasVal = true;
> > +    std::memcpy(storage.buffer, reinterpret_cast<char*>(&y), sizeof(T));
> > +    return *this;
> > +  }
> > +  OptionalStorage &operator=(OptionalStorage &&O) = default;
> > +
> > +  OptionalStorage &operator=(const T &y) {
> > +    hasVal = true;
> > +    std::memcpy(storage.buffer, reinterpret_cast<char const*>(&y), sizeof(T));
> > +    return *this;
> > +  }
> > +  OptionalStorage &operator=(const OptionalStorage &O) = default;
> > +
> > +  ~OptionalStorage() = default;
> > +
> > +  T *getPointer() {
> > +    assert(hasVal);
> > +    return reinterpret_cast<T *>(storage.buffer);  }  const T
> > + *getPointer() const {
> > +    assert(hasVal);
> > +    return reinterpret_cast<const T *>(storage.buffer);  }
> > +
> > +  void reset() { hasVal = false; }
> > +};
> > +
> >  } // namespace optional_detail
> >
> >  template <typename T> class Optional {
> >
> > Modified: llvm/trunk/unittests/ADT/OptionalTest.cpp
> > URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/OptionalTest.cpp?rev=354051&r1=354050&r2=354051&view=diff
> > ==============================================================================
> > --- llvm/trunk/unittests/ADT/OptionalTest.cpp (original)
> > +++ llvm/trunk/unittests/ADT/OptionalTest.cpp Thu Feb 14 11:17:00 2019
> > @@ -18,6 +18,12 @@ using namespace llvm;
> >
> >  namespace {
> >
> > +static_assert(llvm::is_trivially_copyable<Optional<int>>::value,
> > +              "trivially copyable");
> > +
> > +static_assert(llvm::is_trivially_copyable<Optional<std::array<int, 3>>>::value,
> > +              "trivially copyable");
> > +
> >  struct NonDefaultConstructible {
> >    static unsigned CopyConstructions;
> >    static unsigned Destructions;
> > @@ -45,6 +51,10 @@ unsigned NonDefaultConstructible::CopyCo  unsigned NonDefaultConstructible::Destructions = 0;  unsigned NonDefaultConstructible::CopyAssignments = 0;
> >
> > +static_assert(
> > +    !llvm::is_trivially_copyable<Optional<NonDefaultConstructible>>::value,
> > +    "not trivially copyable");
> > +
> >  // Test fixture
> >  class OptionalTest : public testing::Test {  }; @@ -203,6 +213,10 @@ struct MultiArgConstructor {  };  unsigned MultiArgConstructor::Destructions = 0;
> >
> > +static_assert(
> > +    !llvm::is_trivially_copyable<Optional<MultiArgConstructor>>::value,
> > +    "not trivially copyable");
> > +
> >  TEST_F(OptionalTest, Emplace) {
> >    MultiArgConstructor::ResetCounts();
> >    Optional<MultiArgConstructor> A;
> > @@ -250,6 +264,9 @@ unsigned MoveOnly::MoveConstructions = 0  unsigned MoveOnly::Destructions = 0;  unsigned MoveOnly::MoveAssignments = 0;
> >
> > +static_assert(!llvm::is_trivially_copyable<Optional<MoveOnly>>::value,
> > +              "not trivially copyable");
> > +
> >  TEST_F(OptionalTest, MoveOnlyNull) {
> >    MoveOnly::ResetCounts();
> >    Optional<MoveOnly> O;
> > @@ -351,6 +368,9 @@ private:
> >  unsigned Immovable::Constructions = 0;
> >  unsigned Immovable::Destructions = 0;
> >
> > +static_assert(!llvm::is_trivially_copyable<Optional<Immovable>>::value,
> > +              "not trivially copyable");
> > +
> >  TEST_F(OptionalTest, ImmovableEmplace) {
> >    Optional<Immovable> A;
> >    Immovable::ResetCounts();
> >
> >
> > _______________________________________________
> > llvm-commits mailing list
> > llvm-commits at lists.llvm.org
> > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
> > _______________________________________________
> > llvm-commits mailing list
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