[Bug tree-optimization/68775] New: spec2006 test case 465.tonto fails with the gcc 6.0 fortran compiler

[seurer at linux dot vnet.ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68775

            Bug ID: 68775
           Summary: spec2006 test case 465.tonto fails with the gcc 6.0
                    fortran compiler
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: seurer at linux dot vnet.ibm.com
  Target Milestone: ---

The spec2006 test case 465.tonto fails with the gcc 6.0 fortran compiler on
powerpc.  The failure started with revision r230855.  The compilation works but
the output of the test is wrong.


r230855 | rguenth | 2015-11-25 02:53:22 -0600 (Wed, 25 Nov 2015) | 6 lines

2015-11-25  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/68492
        * tree-vect-slp.c (vect_build_slp_tree): Consistently build up
        op from scalars after operand swapping.

Options used were:  -m64 -O3 -mcpu=power8 -fpeel-loops -funroll-loops
-ffast-math -fvect-cost-model -mpopcntd -mrecip=rsqrt

Minimal option set to cause the failure:  -m64 -O3 -mcpu=power8 -ffast-math

Note that it succeeds with -mcpu=power7