[Bug c++/99012] New: gcc-8.4.0 on aarch64 hits internal error during RTL pass: expand if `std::copysign` is used

[nikita.shulga at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99012

            Bug ID: 99012
           Summary: gcc-8.4.0 on aarch64 hits internal error during RTL
                    pass: expand if `std::copysign` is used
           Product: gcc
           Version: 8.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: nikita.shulga at gmail dot com
  Target Milestone: ---

Created attachment 50146
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50146&action=edit
gzipped preprocessed file that hits the issue

To repro, run `g++-8 -O3 -c BinaryOpsKernel.cpp.DEFAULT.E.cpp` and it will fail
with:
```
/usr/include/c++/8/cmath: In function
‘at::native::{anonymous}::cpu_kernel(at::TensorIteratorBase&, func_t&&) [with
func_t =
at::native::{anonymous}::div_floor_kernel(at::TensorIterator&)::<lambda()>::<lambda()>::<lambda(scalar_t,
scalar_t)>]::<lambda(char**, const int64_t*, int64_t)>::<lambda(size_t)>’:
/usr/include/c++/8/cmath:1287:31: internal compiler error: Segmentation fault
   { return __builtin_copysignf(__x, __y); }
            ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
```