On Tue, 18 Jan 2022 at 11:04, Jonathan Wakely <jwakely(a)redhat.com> wrote:
On Tue, 18 Jan 2022 at 10:29, Frantisek Zatloukal <fzatlouk(a)redhat.com>
wrote:
>
>
> On Fri, Jan 14, 2022 at 3:33 PM Jakub Jelinek <jakub(a)redhat.com> wrote:
>
>> If there are bugs on the compiler side, please let me know immediately,
>> so that those bugs can be fixed before the mass rebuild next week.
>>
>
> While I was trying to rebuild some Intel components, i've encountered
> this issue, which seems to be caused by libstdc. It affects
> intel-graphics-compiler (not yet in Fedora). That is compiled with clang,
> however, since gcc/libstdc 12, I am hitting this:
>
>
/builddir/build/BUILD/intel-graphics-compiler-igc-1.0.9933/IGC/VectorCompiler/lib/GenXCodeGen/GenXLiveness.cpp:590:46:
> error: call to constructor of 'LiveRangeMap_t::value_type' (aka
'pair<const
> llvm::genx::SimpleValue, llvm::genx::LiveRange *>') is ambiguous
> auto [i, isInserted] =
> LiveRangeMap.insert(LiveRangeMap_t::value_type(V, 0));
> ^
> ~~~~
>
/usr/bin/../lib/gcc/x86_64-redhat-linux/12/../../../../include/c++/12/bits/stl_pair.h:425:17:
> note: candidate constructor [with _U1 = const llvm::genx::SimpleValue, _U2
> = llvm::genx::LiveRange *, $2 = true]
> constexpr pair(const _T1& __a, const _T2& __b)
> ^
>
/usr/bin/../lib/gcc/x86_64-redhat-linux/12/../../../../include/c++/12/bits/stl_pair.h:492:18:
> note: candidate constructor [with _U1 = llvm::genx::SimpleValue &, $1 =
> true]
> constexpr pair(_U1&& __x, __null_ptr_constant)
> ^
> 1 error generated.
>
> I've tried to locally recompile clang and llvm against the new libstdc
> (as it seems ambiguousness is caused by #if _GLIBCXX_USE_DEPRECATED being
> met), but that didn't help. Maybe I am missing some library that needs to
> be recompiled too. Anyhow, is this expected behavior?
>
> The affected file is this one:
>
https://github.com/intel/intel-graphics-compiler/blob/master/IGC/VectorCo...
>
I think the code is just wrong, and should use nullptr instead of 0 in
that initializer on line 590.
Even better would be to stop creating the unnecessary temporary:
auto [i, isInserted] = LiveRangeMap.emplace(V, nullptr);
It's related to
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101124
though. I tried to keep that old incorrect code working, but apparently
failed.