https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88579
--- Comment #3 from Harald Anlauf <anlauf at gmx dot de> ---
Suggested testcase for the patch in comment #1, derived from power_7.f90:
! { dg-do run }
! { dg-additional-options "-fdump-tree-original" }
! Test optimizations for bases that are powers of 2.
program p
integer :: i
integer(8) :: v
v = 1
do i=1,7
v = v * 256_8
if (v /= 256_8 ** i) stop 1
end do
v = 1
do i=1,3
v = v * 65536_8
if (v /= 65536_8 ** i) stop 2
end do
end program p
! { dg-final { scan-tree-dump-not "_gfortran_pow" "original" } }
Don't know how to handle optimizations for (-2**m)**n, maybe someone
with better knowledge of the frontend can drop a hint.
