[Bug tree-optimization/32087] New: ICE with FORTRAN and -fprefetch-loop-arrays

["sje at cup dot hp dot com" <gcc-bugzilla at gcc dot gnu dot org>]

The following program will ICE when compiled with -O2 -fprefetch-loop-arrays on
a x86_64 box or on IA64 box (Linux and/or HP-UX in 64 bit mode). 
scale_bbs_frequencies_int is called with nbbs=1, num=0, and den=0.  Since we do
a division by den, the compiler aborts during the division.  If we give X a
size of 2 instead of 1, the ICE does not happen.


$ cat x.f
      SUBROUTINE TFHF(HINT,NVAR,NCOORD,LDI)
      IMPLICIT DOUBLE PRECISION(A-H,O-Z)
      DIMENSION HINT(LDI,NVAR)
      COMMON /FMCOM / X(1)
      LHI   = 1 + LOADFM + (NCOORD*NVAR) + (NCOORD*NCOORD+NCOORD)/2
      LOC = LHI-1
      DO 160 I = 1,NVAR
         DO 150 J = 1,I
            LOC = LOC + 1
            HINT(I,J) = X(LOC)
            HINT(J,I) = X(LOC)
  150    CONTINUE
  160 CONTINUE
      RETURN
      END

$ gfortran -O2 -fprefetch-loop-arrays -c x.f

x.f: In function 'tfhf':
x.f:1: internal compiler error: Floating point exception
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.


-- 
           Summary: ICE with FORTRAN and -fprefetch-loop-arrays
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: sje at cup dot hp dot com
GCC target triplet: x86_64-*-* ia64-*-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32087