[Bug target/63749] New: [4.9/5 Regression] registers may not be the same

["doko at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63749

            Bug ID: 63749
           Summary: [4.9/5 Regression] registers may not be the same
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: doko at gcc dot gnu.org

Created attachment 33894
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33894&action=edit
test case

seen with current 4.9 branch and trunk on arm-linux-gnueabihf

$ gcc-4.8 -O2 -c reg.c
$ gcc -O2 -c reg.c
/tmp/ccQvkuYw.s: Assembler messages:
/tmp/ccQvkuYw.s:106: Error: registers may not be the same -- `str r2,[r2],#4'
$ gcc -O1 -fexpensive-optimizations -fschedule-insns -c reg.c
/tmp/ccy5nxu8.s: Assembler messages:
/tmp/ccy5nxu8.s:81: Error: registers may not be the same -- `str r2,[r2],#4'