[Bug libfortran/93871] COTAN is slow for complex types

[sgk at troutmask dot apl.washington.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93871

--- Comment #12 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Fri, Feb 21, 2020 at 08:40:22PM +0000, sgk at troutmask dot
apl.washington.edu wrote:
> 
> Ugh, this diff fixes constant-folding (without your mpc_sincos) patch.
> 
> Index: gcc/fortran/simplify.c
> ===================================================================
> --- gcc/fortran/simplify.c (revision 280157)
> +++ gcc/fortran/simplify.c (working copy)
> @@ -7782,26 +7787,32 @@ gfc_simplify_sum (gfc_expr *array, gfc_expr *dim, gfc_
>  gfc_expr *
>  gfc_simplify_cotan (gfc_expr *x)
>  {
> -  gfc_expr *result;
> +  gfc_expr *arg, *result;
>    mpc_t swp, *val;
> 
> -  if (x->expr_type != EXPR_CONSTANT)
> +  if (x->expr_type == EXPR_FUNCTION
> +      && strcmp(x->value.function.isym->name, "cotan") == 0)

  if (x->expr_type == EXPR_FUNCTION
      && (strcmp(x->value.function.isym->name, "cotan") == 0
          || strcmp(x->value.function.isym->name, "dcotan") == 0))

Something is broken. :(