gcc/testsuite/gfortran.dg/power_3.f90

   1 ! { dg-do run }
   2 ! { dg-options "-ffrontend-optimize -fdump-tree-original" }
   3 ! PR 57071 - Check that (-1)**k is transformed into 1-2*iand(k,1).
   4 program main
   5   implicit none
   6   integer, parameter :: n = 3
   7   integer(kind=8), dimension(-n:n) :: a, b
   8   integer, dimension(-n:n) :: c, d, e
   9   integer :: m
  10   integer :: i, v
  11   integer (kind=2) :: i2
  12
  13   m = n
  14   v = -1
  15   ! Test in scalar expressions
  16   do i=-n,n
  17      if (v**i /= (-1)**i) call abort
  18   end do
  19
  20   ! Test in array constructors
  21   a(-m:m) = [ ((-1)**i, i= -m, m) ]
  22   b(-m:m) = [ (   v**i, i= -m, m) ]
  23   if (any(a .ne. b)) call abort
  24
  25   ! Test in array expressions
  26   c = [ ( i, i = -n , n ) ]
  27   d = (-1)**c
  28   e = v**c
  29   if (any(d .ne. e)) call abort
  30
  31   ! Test in different kind expressions
  32   do i2=-n,n
  33      if (v**i2 /= (-1)**i2) call abort
  34   end do
  35
  36 end program main
  37 ! { dg-final { scan-tree-dump-times "_gfortran_pow_i4_i4" 4 "original" } }