[Bug middle-end/67518] New: [6 Regression] ISL: position out of bounds

[Joost.VandeVondele at mat dot ethz.ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67518

            Bug ID: 67518
           Summary: [6 Regression] ISL: position out of bounds
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: Joost.VandeVondele at mat dot ethz.ch
  Target Milestone: ---

The testcase below triggers a bug in graphite and leads to:

> gfortran  -c -floop-nest-optimize -O2 -ffast-math bug.f90
/data/vjoost/toolchain-trunk/build/gcc-master/isl/isl_aff.c:944: position out
of bounds
bug.f90:14:0:

  FUNCTION
exp_radius_very_extended(la_min,la_max,lb_min,lb_max,pab,o1,o2,ra,rb,rp,&
^
internal compiler error: Aborted
0xb3f37f crash_signal
        /data/vjoost/toolchain-trunk/build/gcc-master/gcc/toplev.c:352
0x12f9bd2 isl_handle_error
        /data/vjoost/toolchain-trunk/build/gcc-master/isl/isl_ctx.c:96
0x12c4a91 isl_aff_set_coefficient_si
        /data/vjoost/toolchain-trunk/build/gcc-master/isl/isl_aff.c:943
0x1196d7a extract_affine_chrec
       
/data/vjoost/toolchain-trunk/build/gcc-master/gcc/graphite-sese-to-poly.c:600
0x1196d7a extract_affine
       
/data/vjoost/toolchain-trunk/build/gcc-master/gcc/graphite-sese-to-poly.c:788
0x1198354 build_loop_iteration_domains
       
/data/vjoost/toolchain-trunk/build/gcc-master/gcc/graphite-sese-to-poly.c:1024
0x119a7df build_scop_iteration_domain
       
/data/vjoost/toolchain-trunk/build/gcc-master/gcc/graphite-sese-to-poly.c:1389
0x119a7df build_poly_scop(scop*)
       
/data/vjoost/toolchain-trunk/build/gcc-master/gcc/graphite-sese-to-poly.c:3162
0x11872e5 graphite_transform_loops()
        /data/vjoost/toolchain-trunk/build/gcc-master/gcc/graphite.c:282
0x1187940 graphite_transforms
        /data/vjoost/toolchain-trunk/build/gcc-master/gcc/graphite.c:317
0x1187940 execute
        /data/vjoost/toolchain-trunk/build/gcc-master/gcc/graphite.c:394


> cat bug.f90
MODULE ao_util
    INTEGER, PARAMETER :: dp=8
CONTAINS
  FUNCTION exp_radius(l,alpha,threshold,prefactor,epsin) RESULT(radius)
    REAL(KIND=dp), INTENT(IN)                :: alpha, threshold, prefactor
    REAL(KIND=dp), INTENT(IN), OPTIONAL      :: epsin
    DO
       IF (iter.gt.maxiter) THEN
          CALL stop_program(routineN,moduleN,1,"exceeded")
       ENDIF
    ENDDO
    CALL stop_program(routineN,moduleN,1,"exceeded")
  END FUNCTION exp_radius
 FUNCTION
exp_radius_very_extended(la_min,la_max,lb_min,lb_max,pab,o1,o2,ra,rb,rp,&
                          zetp,eps,prefactor,cutoff,epsin) RESULT(radius)
    REAL(KIND=dp), DIMENSION(:, :), &
      OPTIONAL, POINTER                      :: pab
    REAL(KIND=dp), INTENT(IN)                :: ra(3), rb(3), rp(3), zetp, &
                                                eps, prefactor, cutoff
    REAL(KIND=dp)                            :: bini, binj, coef(0:20), &
                                                epsin_local, polycoef(0:60), &
                                                rad_b, s1, s2
    IF (PRESENT(pab)) THEN
    ENDIF
    DO lxa=0,la_max
    DO lxb=0,lb_max
       coef(0:la_max+lb_max)=0.0_dp
       DO i=0,lxa
          DO j=0,lxb
             coef(lxa+lxb-i-j)=coef(lxa+lxb-i-j) + bini*binj*s1*s2
          ENDDO
       ENDDO
       DO i=0,lxa+lxb
          polycoef(i)=MAX(polycoef(i),coef(i))
       ENDDO
    ENDDO
    ENDDO
    DO i=0,la_max+lb_max
          radius=MAX(radius,exp_radius(i,zetp,eps,polycoef(i),epsin_local) )
    ENDDO
  END FUNCTION exp_radius_very_extended
END MODULE ao_util