[Bug target/66959] New: Bad code generated for union type punning of NEON intrinsic types on ARM64

[dpb at corrigendum dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66959

            Bug ID: 66959
           Summary: Bad code generated for union type punning of NEON
                    intrinsic types on ARM64
           Product: gcc
           Version: 4.9.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dpb at corrigendum dot ru
  Target Milestone: ---

Created attachment 36024
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36024&action=edit
Original source

Original and preprocessed source attached.

$ gcc -dumpmachine
aarch64-linux-gnu

$ gcc -O0 -std=c11 test.c && ./a.out ; echo $?
0
$ gcc -O1 -std=c11 test.c && ./a.out ; echo $?
1

Reproduced with 4.9.3 and the head of the 4.9 branch. Couldn't reproduce on
trunk.