Remove duplicate inline implementation of issignalingf

  From: "Paul A. Clarke" <pc@us.ibm.com>

Very recent commit 854e91bf6b4221f424ffa13b9ef50f35623b7b74 enabled
inline of issignalingf() in general (__issignalingf in include/math.h).
There is another implementation for an inline use of issignalingf
(issignalingf_inline in sysdeps/ieee754/flt-32/math_config.h)
which could instead make use of the new enablement.

Replace the use of issignalingf_inline with __issignaling.

The implementations are slightly different, and compile to slightly
different code, but I measured no significant performance difference.

The second implementation was brought to my attention by:
Suggested-by: Joseph Myers <joseph@codesourcery.com>

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
---
 sysdeps/ieee754/flt-32/e_powf.c      | 4 ++--
 sysdeps/ieee754/flt-32/math_config.h | 9 ---------
 2 files changed, 2 insertions(+), 11 deletions(-)
  

On 21/11/2019 15:06, Paul A. Clarke wrote:
> From: "Paul A. Clarke" <pc@us.ibm.com>
> 
> Very recent commit 854e91bf6b4221f424ffa13b9ef50f35623b7b74 enabled
> inline of issignalingf() in general (__issignalingf in include/math.h).
> There is another implementation for an inline use of issignalingf
> (issignalingf_inline in sysdeps/ieee754/flt-32/math_config.h)
> which could instead make use of the new enablement.
> 
> Replace the use of issignalingf_inline with __issignaling.
> 
> The implementations are slightly different, and compile to slightly
> different code, but I measured no significant performance difference.
> 
> The second implementation was brought to my attention by:
> Suggested-by: Joseph Myers <joseph@codesourcery.com>
> 
> Signed-off-by: Paul A. Clarke <pc@us.ibm.com>

We do not use sign-off.

LGTM.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  sysdeps/ieee754/flt-32/e_powf.c      | 4 ++--
>  sysdeps/ieee754/flt-32/math_config.h | 9 ---------
>  2 files changed, 2 insertions(+), 11 deletions(-)
> 
> diff --git a/sysdeps/ieee754/flt-32/e_powf.c b/sysdeps/ieee754/flt-32/e_powf.c
> index 4947ae2..d4f52f2 100644
> --- a/sysdeps/ieee754/flt-32/e_powf.c
> +++ b/sysdeps/ieee754/flt-32/e_powf.c
> @@ -158,9 +158,9 @@ __powf (float x, float y)
>        if (__glibc_unlikely (zeroinfnan (iy)))
>  	{
>  	  if (2 * iy == 0)
> -	    return issignalingf_inline (x) ? x + y : 1.0f;
> +	    return __issignalingf (x) ? x + y : 1.0f;
>  	  if (ix == 0x3f800000)
> -	    return issignalingf_inline (y) ? x + y : 1.0f;
> +	    return __issignalingf (y) ? x + y : 1.0f;
>  	  if (2 * ix > 2u * 0x7f800000 || 2 * iy > 2u * 0x7f800000)
>  	    return x + y;
>  	  if (2 * ix == 2 * 0x3f800000)
> diff --git a/sysdeps/ieee754/flt-32/math_config.h b/sysdeps/ieee754/flt-32/math_config.h
> index c5e9299..57cf441 100644
> --- a/sysdeps/ieee754/flt-32/math_config.h
> +++ b/sysdeps/ieee754/flt-32/math_config.h
> @@ -101,15 +101,6 @@ asdouble (uint64_t i)
>    return u.f;
>  }
>  
> -static inline int
> -issignalingf_inline (float x)
> -{
> -  uint32_t ix = asuint (x);
> -  if (HIGH_ORDER_BIT_IS_SET_FOR_SNAN)
> -    return (ix & 0x7fc00000) == 0x7fc00000;
> -  return 2 * (ix ^ 0x00400000) > 2u * 0x7fc00000;
> -}
> -
>  #define NOINLINE __attribute__ ((noinline))
>  
>  attribute_hidden float __math_oflowf (uint32_t);
>
  

On Thu, 21 Nov 2019, Paul A. Clarke wrote:

> From: "Paul A. Clarke" <pc@us.ibm.com>
> 
> Very recent commit 854e91bf6b4221f424ffa13b9ef50f35623b7b74 enabled
> inline of issignalingf() in general (__issignalingf in include/math.h).
> There is another implementation for an inline use of issignalingf
> (issignalingf_inline in sysdeps/ieee754/flt-32/math_config.h)
> which could instead make use of the new enablement.
> 
> Replace the use of issignalingf_inline with __issignaling.

I think it's better to replace it with calls to issignaling (the 
type-generic macro), rather than to __issignalingf (the inline function).  
That way, if in future GCC gets __builtin_issignaling and glibc's <math.h> 
starts to use it, this code will automatically start using 
__builtin_issignaling via the macro definition.