gcc/testsuite/gfortran.dg/mod_sign0_1.f90

   1 ! { dg-do run }
   2 ! PR fortran/49010
   3 ! MOD/MODULO sign of zero.
   4
   5 ! We wish to provide the following guarantees:
   6
   7 ! MOD(A, P): The result has the sign of A and a magnitude less than
   8 ! that of P.
   9
  10 ! MODULO(A, P): The result has the sign of P and a magnitude less than
  11 ! that of P.
  12
  13 ! Here we test only with constant arguments (evaluated with
  14 ! mpfr_fmod), as we don't want to cause failures on targets with a
  15 ! crappy libm. But, a target where fmod follows C99 Annex F is
  16 ! fine. Also, targets where GCC inline expands fmod (such as x86(-64))
  17 ! are also fine.
  18 program mod_sign0_1
  19   implicit none
  20   real :: r, t
  21
  22   r = mod (4., 2.)
  23   t = sign (1., r)
  24   if (t < 0.) call abort
  25
  26   r = modulo (4., 2.)
  27   t = sign (1., r)
  28   if (t < 0.) call abort
  29
  30   r = mod (-4., 2.)
  31   t = sign (1., r)
  32   if (t > 0.) call abort
  33
  34   r = modulo (-4., 2.)
  35   t = sign (1., r)
  36   if (t < 0.) call abort
  37
  38   r = mod (4., -2.)
  39   t = sign (1., r)
  40   if (t < 0.) call abort
  41
  42   r = modulo (4., -2.)
  43   t = sign (1., r)
  44   if (t > 0.) call abort
  45
  46   r = mod (-4., -2.)
  47   t = sign (1., r)
  48   if (t > 0.) call abort
  49
  50   r = modulo (-4., -2.)
  51   t = sign (1., r)
  52   if (t > 0.) call abort
  53
  54 end program mod_sign0_1