[Bug tree-optimization/41811] New: graphite miscompiles 454.calculix of the SPEC 2k6

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

The kernel that is miscompiled is in shape20h.f and it looks like this:

      do i=1,3
        do j=1,3
          xs(i,j)=0.d0
          do k=1,20
            xs(i,j)=xs(i,j)+xl(i,k)*shp(j,k)
          enddo
        enddo
      enddo

There is an interchange of the j and k loops that is applied to the
kernel.  The statement induction variable order is interchanged for
scat_5 and scat_3, as in S5(scat_1,scat_5,scat_3).  The code generated
by CLooG looks like this:

for (scat_1=0;scat_1<=2;scat_1++) {
  S3(scat_1) ;
  for (scat_3=0;scat_3<=1;scat_3++) {
    S4(scat_1,scat_3) ;
    for (scat_5=0;scat_5<=2;scat_5++) {
      S5(scat_1,scat_5,scat_3) ;
      S6(scat_1,scat_5,scat_3) ;
    }
    S7(scat_1,scat_3) ;
    S26(scat_1,scat_3) ;
    S8(scat_1,scat_3) ;
  }
  S4(scat_1,2) ;
  for (scat_5=0;scat_5<=2;scat_5++) {
    S5(scat_1,scat_5,2) ;
    S6(scat_1,scat_5,2) ;
  }
  S7(scat_1,2) ;
  S26(scat_1,2) ;
  for (scat_3=3;scat_3<=18;scat_3++) {
    for (scat_5=0;scat_5<=2;scat_5++) {
      S5(scat_1,scat_5,scat_3) ;
      S6(scat_1,scat_5,scat_3) ;
    }
  }
  for (scat_5=0;scat_5<=2;scat_5++) {
    S5(scat_1,scat_5,19) ;
  }
}


-- 
           Summary: graphite miscompiles 454.calculix of the SPEC 2k6
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: spop at gcc dot gnu dot org
        ReportedBy: spop at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41811