backport: re PR fortran/85544 (ICE in gfc_conv_scalarized_array_ref, at fortran/trans-array.c:3385)

2018-12-22  Thomas Koenig  <tkoenig@gcc.gnu.org>

    Backport from trunk
    PR fortran/85544
    * gfortran.dg/power_7.f90: New test.

From-SVN: r267348

gcc/testsuite/gfortran.dg/power_7.f90

+! { dg-do run }
+! { dg-additional-options "-fdump-tree-original" }
+! PR 85544 - this used to ICE.
+program p
+   integer, parameter :: na = -3, ne = 10
+   integer :: i, a(na:ne), b(na:ne)
+   integer :: v
+   a = [(i, i=na, ne)]
+   b = [2**a]
+   if (any (b /= [0,0,0,1,2,4,8,16,32,64,128,256,512,1024])) stop 1
+   b = [1**a]
+   if (any (b /= 1)) stop 2
+   b = [(-1)**a]
+   if (any (b /= [-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1]) )stop 3
+   b = [8**a]
+   if (any (b /= [0,0,0,1,8,64,512,4096,32768,262144,2097152,16777216,&
+        134217728,1073741824])) stop 4
+   b = [4**a]
+   if (any (b /= [0,0,0,1,4,16,64,256,1024,4096,16384,65536,262144,1048576])) stop 5
+   
+   v = 1
+   do i=1,6
+      v = v * 16
+      if (v /= 16**i) stop 6 
+   end do
+ end program p
+! { dg-final { scan-tree-dump-not "_gfortran_pow" "original" } }