RE: [PATCH v2] Remove isinf uses that rely on signed return value

["Wilco Dijkstra" <wdijkstr at arm dot com>]

> Wilco Dijkstra wrote:
> I found a few more cases where isinf is used to get the signbit. Clean these up to improve the
> readability and maintainability and allow inlining. Generated code is virtually identical once
> isinf is inlined using the GCC builtin.
> 
> OK for commit?

Ping



> 2015-08-20  Wilco Dijkstra  <wdijkstr@arm.com>
> 
> 	* math/w_tgamma.c (__ieee754_gamma_r): Use explicit sign check.
> 	* math/w_tgammaf.c (__ieee754_gammaf_r): Likewise.
> 	* math/w_tgammal.c (__ieee754_gammal_r): Likewise.
> 	* stdio-common/printf_fp.c (___printf_fp):
> 	Use signbit to get the sign. Use isinf macro to allow inlining.
> 	* stdio-common/printf_fphex.c (__printf_fphex): Likewise.
> 	* stdio-common/printf_size.c (__printf_size): Likewise.c
> 
> ---
>  math/w_tgamma.c             |  2 +-
>  math/w_tgammaf.c            |  2 +-
>  math/w_tgammal.c            |  2 +-
>  stdio-common/printf_fp.c    | 13 +++++--------
>  stdio-common/printf_fphex.c | 10 +++-------
>  stdio-common/printf_size.c  | 19 +++++++++----------
>  6 files changed, 20 insertions(+), 28 deletions(-)
> 
> diff --git a/math/w_tgamma.c b/math/w_tgamma.c
> index 1ca7765..99b6029 100644
> --- a/math/w_tgamma.c
> +++ b/math/w_tgamma.c
> @@ -26,7 +26,7 @@ __tgamma(double x)
>  	double y = __ieee754_gamma_r(x,&local_signgam);
> 
>  	if(__glibc_unlikely (!isfinite (y) || y == 0)
> -	   && (isfinite (x) || isinf (x) < 0)
> +	   && (isfinite (x) || (isinf (x) && x < 0.0))
>  	   && _LIB_VERSION != _IEEE_) {
>  	  if (x == 0.0)
>  	    return __kernel_standard(x,x,50); /* tgamma pole */
> diff --git a/math/w_tgammaf.c b/math/w_tgammaf.c
> index 9ed7660..dfce894 100644
> --- a/math/w_tgammaf.c
> +++ b/math/w_tgammaf.c
> @@ -24,7 +24,7 @@ __tgammaf(float x)
>  	float y = __ieee754_gammaf_r(x,&local_signgam);
> 
>  	if(__glibc_unlikely (!isfinite (y) || y == 0)
> -	   && (isfinite (x) || isinf (x) < 0)
> +	   && (isfinite (x) || (isinf (x) && x < 0.0))
>  	   && _LIB_VERSION != _IEEE_) {
>  	  if (x == (float)0.0)
>  	    /* tgammaf pole */
> diff --git a/math/w_tgammal.c b/math/w_tgammal.c
> index b3a9e4a..50de8cf 100644
> --- a/math/w_tgammal.c
> +++ b/math/w_tgammal.c
> @@ -29,7 +29,7 @@ __tgammal(long double x)
>  	long double y = __ieee754_gammal_r(x,&local_signgam);
> 
>  	if(__glibc_unlikely (!isfinite (y) || y == 0)
> -	   && (isfinite (x) || isinf (x) < 0)
> +	   && (isfinite (x) || (isinf (x) && x < 0.0))
>  	   && _LIB_VERSION != _IEEE_) {
>  	  if(x==0.0)
>  	    return __kernel_standard_l(x,x,250); /* tgamma pole */
> diff --git a/stdio-common/printf_fp.c b/stdio-common/printf_fp.c
> index 3023b20..11f3145 100644
> --- a/stdio-common/printf_fp.c
> +++ b/stdio-common/printf_fp.c
> @@ -332,7 +332,6 @@ ___printf_fp (FILE *fp,
>        fpnum.ldbl = *(const long double *) args[0];
> 
>        /* Check for special values: not a number or infinity.  */
> -      int res;
>        if (isnan (fpnum.ldbl))
>  	{
>  	  is_neg = signbit (fpnum.ldbl);
> @@ -347,9 +346,9 @@ ___printf_fp (FILE *fp,
>  		wspecial = L"nan";
>  	      }
>  	}
> -      else if ((res = __isinfl (fpnum.ldbl)))
> +      else if (isinf (fpnum.ldbl))
>  	{
> -	  is_neg = res < 0;
> +	  is_neg = signbit (fpnum.ldbl);
>  	  if (isupper (info->spec))
>  	    {
>  	      special = "INF";
> @@ -377,11 +376,9 @@ ___printf_fp (FILE *fp,
>        fpnum.dbl = *(const double *) args[0];
> 
>        /* Check for special values: not a number or infinity.  */
> -      int res;
>        if (isnan (fpnum.dbl))
>  	{
> -	  union ieee754_double u = { .d = fpnum.dbl };
> -	  is_neg = u.ieee.negative != 0;
> +	  is_neg = signbit (fpnum.dbl);
>  	  if (isupper (info->spec))
>  	    {
>  	      special = "NAN";
> @@ -393,9 +390,9 @@ ___printf_fp (FILE *fp,
>  	      wspecial = L"nan";
>  	    }
>  	}
> -      else if ((res = __isinf (fpnum.dbl)))
> +      else if (isinf (fpnum.dbl))
>  	{
> -	  is_neg = res < 0;
> +	  is_neg = signbit (fpnum.dbl);
>  	  if (isupper (info->spec))
>  	    {
>  	      special = "INF";
> diff --git a/stdio-common/printf_fphex.c b/stdio-common/printf_fphex.c
> index 6c3b5e9..0627bea 100644
> --- a/stdio-common/printf_fphex.c
> +++ b/stdio-common/printf_fphex.c
> @@ -180,7 +180,7 @@ __printf_fphex (FILE *fp,
>  	}
>        else
>  	{
> -	  if (__isinfl (fpnum.ldbl))
> +	  if (isinf (fpnum.ldbl))
>  	    {
>  	      if (isupper (info->spec))
>  		{
> @@ -204,7 +204,6 @@ __printf_fphex (FILE *fp,
>        /* Check for special values: not a number or infinity.  */
>        if (isnan (fpnum.dbl.d))
>  	{
> -	  negative = fpnum.dbl.ieee.negative != 0;
>  	  if (isupper (info->spec))
>  	    {
>  	      special = "NAN";
> @@ -218,8 +217,7 @@ __printf_fphex (FILE *fp,
>  	}
>        else
>  	{
> -	  int res = __isinf (fpnum.dbl.d);
> -	  if (res)
> +	  if (isinf (fpnum.dbl.d))
>  	    {
>  	      if (isupper (info->spec))
>  		{
> @@ -231,11 +229,9 @@ __printf_fphex (FILE *fp,
>  		  special = "inf";
>  		  wspecial = L"inf";
>  		}
> -	      negative = res < 0;
>  	    }
> -	  else
> -	    negative = signbit (fpnum.dbl.d);
>  	}
> +      negative = signbit (fpnum.dbl.d);
>      }
> 
>    if (special)
> diff --git a/stdio-common/printf_size.c b/stdio-common/printf_size.c
> index 7dcd58e..216f170 100644
> --- a/stdio-common/printf_size.c
> +++ b/stdio-common/printf_size.c
> @@ -108,7 +108,7 @@ __printf_size (FILE *fp, const struct printf_info *info,
>    fpnum;
>    const void *ptr = &fpnum;
> 
> -  int fpnum_sign = 0;
> +  int is_neg = 0;
> 
>    /* "NaN" or "Inf" for the special cases.  */
>    const char *special = NULL;
> @@ -117,7 +117,6 @@ __printf_size (FILE *fp, const struct printf_info *info,
>    struct printf_info fp_info;
>    int done = 0;
>    int wide = info->wide;
> -  int res;
> 
>    /* Fetch the argument value.	*/
>  #ifndef __NO_LONG_DOUBLE_MATH
> @@ -130,11 +129,11 @@ __printf_size (FILE *fp, const struct printf_info *info,
>  	{
>  	  special = "nan";
>  	  wspecial = L"nan";
> -	  // fpnum_sign = 0;	Already zero
> +	  // is_neg = 0;	Already zero
>  	}
> -      else if ((res = __isinfl (fpnum.ldbl)))
> +      else if (isinf (fpnum.ldbl))
>  	{
> -	  fpnum_sign = res;
> +	  is_neg = signbit (fpnum.ldbl);
>  	  special = "inf";
>  	  wspecial = L"inf";
>  	}
> @@ -155,11 +154,11 @@ __printf_size (FILE *fp, const struct printf_info *info,
>  	{
>  	  special = "nan";
>  	  wspecial = L"nan";
> -	  // fpnum_sign = 0;	Already zero
> +	  // is_neg = 0;	Already zero
>  	}
> -      else if ((res = __isinf (fpnum.dbl.d)))
> +      else if (isinf (fpnum.dbl.d))
>  	{
> -	  fpnum_sign = res;
> +	  is_neg = signbit (fpnum.dbl.d);
>  	  special = "inf";
>  	  wspecial = L"inf";
>  	}
> @@ -175,14 +174,14 @@ __printf_size (FILE *fp, const struct printf_info *info,
>      {
>        int width = info->prec > info->width ? info->prec : info->width;
> 
> -      if (fpnum_sign < 0 || info->showsign || info->space)
> +      if (is_neg || info->showsign || info->space)
>  	--width;
>        width -= 3;
> 
>        if (!info->left && width > 0)
>  	PADN (' ', width);
> 
> -      if (fpnum_sign < 0)
> +      if (is_neg)
>  	outchar ('-');
>        else if (info->showsign)
>  	outchar ('+');
> --
> 1.9.1