[Bug tree-optimization/78114] New: [7 regression] gfortran.dg/vect/fast-math-mgrid-resid.f FAILs

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78114

            Bug ID: 78114
           Summary: [7 regression]
                    gfortran.dg/vect/fast-math-mgrid-resid.f FAILs
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
                CC: amker at gcc dot gnu.org
  Target Milestone: ---
            Target: i?86-*-*

Between 20161011 and 20161013, the gfortran.dg/vect/fast-math-mgrid-resid.f
started
to FAIL

FAIL: gfortran.dg/vect/fast-math-mgrid-resid.f   -O   scan-tree-dump-times pcom
"Executing predictive commoning without unrolling" 2

for 32-bit x86 (seen on Solaris, Linux, and Darwin).

Most likely introduced by this patch:


changeset:   33495:0318d4fdc3ab
user:        amker@138bc75d-0d04-0410-961f-82ee72b054a4
date:        Thu Oct 13 11:05:53 2016 +0000
files:       gcc/ChangeLog gcc/testsuite/ChangeLog
gcc/testsuite/gfortran.dg/vec
t/fast-math-mgrid-resid.f gcc/tree-predcom.c
description:
* tree-predcom.c (tree_predictive_commoning_loop): Skip loop that only
        iterates 1 time.

        gcc/testsuite
        * gfortran.dg/vect/fast-math-mgrid-resid.f: New test string.

  Rainer