[Bug target/50091] New: [4.5/4.6/4.7 Regression] -fstack-check gives bad assembly on powerpc-apple-darwin9

["dominiq at lps dot ens.fr" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50091

             Bug #: 50091
           Summary: [4.5/4.6/4.7 Regression] -fstack-check gives bad
                    assembly on powerpc-apple-darwin9
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: dominiq@lps.ens.fr
                CC: iains@gcc.gnu.org, spop@gcc.gnu.org
              Host: powerpc-apple-darwin9
            Target: powerpc-apple-darwin9
             Build: powerpc-apple-darwin9


On powerpc-apple-darwin9 I get

FAIL: gcc.dg/graphite/run-id-pr47653.c (test for excess errors)

The error is

[karma] f90/bug% gcc47 -O -fstack-check=generic -ftree-pre -fgraphite-identity
/opt/gcc/work/gcc/testsuite/gcc.dg/graphite/run-id-pr47653.c
/var/tmp//ccQC61mg.s:12:Parameter syntax error (parameter 1)
/var/tmp//ccQC61mg.s:13:Parameter syntax error (parameter 1)

The syntax error comming from "stw 0,..." in

...
        stw 0,-12284(r1)
        mr r0,r1
        stw 0,-12556(r1)
...

It turns out that -fstack-check=generic (or -fstack-check) is enough to trigger
the error for gcc 4.5.3, 4.6.1, and trunk, but not for 4.4.6. I have tested
some C files and this seems quite generic although
gcc/testsuite/gcc.dg/pr48134.c assembles with -O or -O1, but not with -O2.

QUESTION for graphite: is -fstack-check=generic really necessary for
gcc.dg/graphite/run-id-pr47653.c?