[Bug tree-optimization/46297] New: [4.6 Regression] gfortran.dg/g77/980701-0.f FAILs with -Os -fno-asynchronous-unwind-tables

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46297

           Summary: [4.6 Regression] gfortran.dg/g77/980701-0.f FAILs with
                    -Os -fno-asynchronous-unwind-tables
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz


Output:
$ gfortran -Os -fno-asynchronous-unwind-tables 980701-0.f
$ ./a.out 
Aborted

valgrind output:
$ gfortran -Os -fno-asynchronous-unwind-tables 980701-0.f -g
$ valgrind -q ./a.out 
==3171== Conditional jump or move depends on uninitialised value(s)
==3171==    at 0x40078C: x_ (980701-0.f:67)
==3171== 
==3171== Conditional jump or move depends on uninitialised value(s)
==3171==    at 0x40078E: x_ (980701-0.f:67)
==3171== 
Aborted

The warning is for these instructions:
  400781:       f3 0f 10 00             movss  (%rax),%xmm0
  400785:       0f 2e 05 7c 02 00 00    ucomiss 0x27c(%rip),%xmm0        #
400a08 <options.0.1574+0x28>
  40078c:       7a 41                   jp     4007cf <x_+0x14b>
  40078e:       75 3f                   jne    4007cf <x_+0x14b>

Tested revisions:
r166272 - fail
r163636 - fail
r161659 - OK
4.5 r165781 - OK