[Bug c++/91563] New: [9 regression] wrong code

[guillaume at morinfr dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91563

            Bug ID: 91563
           Summary: [9 regression] wrong code
           Product: gcc
           Version: 9.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: guillaume at morinfr dot org
  Target Milestone: ---

Created attachment 46766
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46766&action=edit
test program

Hi,

The attached program aborts with gcc 9.x -O{1,2,3} (including recent version of
the Debian package which has picked recent fixes to the gcc 9 branch). Adding
-fno-strict-aliasing does not make any difference. Full example is uploaded at
https://godbolt.org/z/We99i_

It seems to work correctly with gcc 8.x and the gcc trunk on goldbot.org.

Thank you.