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