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! { dg-do run }
! PR 33683 - we used to pick up the wrong gamma function
! from the library on some systems.
program main
implicit none
integer, parameter :: n_max = 20
double precision, dimension(0:n_max) :: c
double precision :: pi
integer :: n
double precision :: td, xd
real :: ts,xs
pi = 4 * atan(1.d0)
c(0) = 1.
do n=1, n_max
c(n) = (2*n-1)*c(n-1)*0.5d0
end do
do n=1, n_max
xs = n + 0.5
xd = n + 0.5d0
td = c(n)*sqrt(pi)
ts = c(n)*sqrt(pi)
if (abs(gamma(xs)-ts)/ts > 9e-6) call abort
if (abs(gamma(xd)-td)/td > 5e-14) call abort
end do
call tst_s(2.3, gamma(2.3))
call tst_s(3.7, gamma(3.7))
call tst_s(5.5, gamma(5.5))
call tst_d(4.2d0, gamma(4.2d0))
call tst_d(8.1d0, gamma(8.1d0))
contains
subroutine tst_s(a, b)
real :: a, b
if (abs(gamma(a) - b)/b > 1e-6) call abort
end subroutine tst_s
subroutine tst_d(a, b)
double precision :: a,b
if (abs(gamma(a) - b)/b > 5e-14) call abort
end subroutine tst_d
end program main
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