[Bug middle-end/89125] Misoptimization of converting sin(x) and cos(x) into sincos(x,&s,&c)

[sgk at troutmask dot apl.washington.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89125

--- Comment #5 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Wed, Jan 30, 2019 at 08:47:50PM +0000, glisse at gcc dot gnu.org wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89125
> 
> --- Comment #4 from Marc Glisse <glisse at gcc dot gnu.org> ---
> This looks like a target issue, gcc does produce a call to sincos here. So
> please specify your target precisely.
> 

Yes, it seems to be a target issue.  It's i585-*-freebsd
and x86_64-*-freebsd.  

I've found that gcc/config/freebsd.h contains 

#define TARGET_LIBC_HAS_FUNCTION no_c99_libc_has_function

AFAIK, FreeBSD is C99 compliant.  This is an area I haven't worked
in.  I might be able to change this to default_libc_has_function,
but that doesn't include sincos.  So, it seems I need a function,
perhaps, bsd_libc_has_function in targhooks.[ch]

/* Assume that c99 functions are present at the runtime,
   including sincos.  */
bool
bsd_libc_has_function (enum function_class fn_class)
{
  if (fn_class == function_c94
      || fn_class == function_c99_misc
      || fn_class == function_c99_math_complex
      || fn_class == function_sincos)
    return true;

  return false;
}