Re: [PATCH 12/13] Use GCC builtins for round functions if desired.

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On 02/12/2019 11:46, Stefan Liebler wrote:
> This patch is using the corresponding GCC builtin for roundf, round,
> roundl and roundf128 if the USE_FUNCTION_BUILTIN macros are defined to one
> in math-use-builtins.h.
> 
> This is the case for s390 if build with at least --march=z196 --mzarch.
> Otherwise the generic implementation is used.

LGTM, thanks.

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

> ---
>  sysdeps/generic/math-use-builtins.h         | 5 +++++
>  sysdeps/ieee754/dbl-64/s_round.c            | 6 +++++-
>  sysdeps/ieee754/float128/float128_private.h | 3 +++
>  sysdeps/ieee754/flt-32/s_roundf.c           | 6 +++++-
>  sysdeps/ieee754/ldbl-128/s_roundl.c         | 6 +++++-
>  sysdeps/s390/fpu/math-use-builtins.h        | 6 ++++++
>  6 files changed, 29 insertions(+), 3 deletions(-)
> 
> diff --git a/sysdeps/generic/math-use-builtins.h b/sysdeps/generic/math-use-builtins.h
> index ab379f45ba..34ca438a8c 100644
> --- a/sysdeps/generic/math-use-builtins.h
> +++ b/sysdeps/generic/math-use-builtins.h
> @@ -46,4 +46,9 @@
>  #define USE_TRUNCL_BUILTIN 0
>  #define USE_TRUNCF128_BUILTIN 0
>  
> +#define USE_ROUND_BUILTIN 0
> +#define USE_ROUNDF_BUILTIN 0
> +#define USE_ROUNDL_BUILTIN 0
> +#define USE_ROUNDF128_BUILTIN 0
> +
>  #endif /* math-use-builtins.h */

Ok.

> diff --git a/sysdeps/ieee754/dbl-64/s_round.c b/sysdeps/ieee754/dbl-64/s_round.c
> index 8f4b7cff86..00c8485efb 100644
> --- a/sysdeps/ieee754/dbl-64/s_round.c
> +++ b/sysdeps/ieee754/dbl-64/s_round.c
> @@ -23,11 +23,14 @@
>  #include <math_private.h>
>  #include <libm-alias-double.h>
>  #include <stdint.h>
> -
> +#include <math-use-builtins.h>
>  
>  double
>  __round (double x)
>  {
> +#if USE_ROUND_BUILTIN
> +  return __builtin_round (x);
> +#else
>    int64_t i0, j0;
>  
>    EXTRACT_WORDS64 (i0, x);
> @@ -62,5 +65,6 @@ __round (double x)
>  
>    INSERT_WORDS64 (x, i0);
>    return x;
> +#endif /* USE_ROUND_BUILTIN  */
>  }
>  libm_alias_double (__round, round)

Ok.

> diff --git a/sysdeps/ieee754/float128/float128_private.h b/sysdeps/ieee754/float128/float128_private.h
> index 9cd3a63f11..a6c76ce364 100644
> --- a/sysdeps/ieee754/float128/float128_private.h
> +++ b/sysdeps/ieee754/float128/float128_private.h
> @@ -150,6 +150,8 @@
>  #define USE_CEILL_BUILTIN USE_CEILF128_BUILTIN
>  #undef USE_TRUNCL_BUILTIN
>  #define USE_TRUNCL_BUILTIN USE_TRUNCF128_BUILTIN
> +#undef USE_ROUNDL_BUILTIN
> +#define USE_ROUNDL_BUILTIN USE_ROUNDF128_BUILTIN
>  
>  /* IEEE function renames.  */
>  #define __ieee754_acoshl __ieee754_acoshf128
> @@ -358,6 +360,7 @@
>  #define __builtin_floorl __builtin_floorf128
>  #define __builtin_ceill __builtin_ceilf128
>  #define __builtin_truncl __builtin_truncf128
> +#define __builtin_roundl __builtin_roundf128
>  
>  /* Get the constant suffix from bits/floatn-compat.h.  */
>  #define L(x) __f128 (x)

Ok.

> diff --git a/sysdeps/ieee754/flt-32/s_roundf.c b/sysdeps/ieee754/flt-32/s_roundf.c
> index cddab7b505..33304b21f1 100644
> --- a/sysdeps/ieee754/flt-32/s_roundf.c
> +++ b/sysdeps/ieee754/flt-32/s_roundf.c
> @@ -22,11 +22,14 @@
>  
>  #include <math_private.h>
>  #include <libm-alias-float.h>
> -
> +#include <math-use-builtins.h>
>  
>  float
>  __roundf (float x)
>  {
> +#if USE_ROUNDF_BUILTIN
> +  return __builtin_roundf (x);
> +#else
>    int32_t i0, j0;
>  
>    GET_FLOAT_WORD (i0, x);
> @@ -61,5 +64,6 @@ __roundf (float x)
>  
>    SET_FLOAT_WORD (x, i0);
>    return x;
> +#endif /* USE_ROUNDF_BUILTIN  */
>  }
>  libm_alias_float (__round, round)

Ok.

> diff --git a/sysdeps/ieee754/ldbl-128/s_roundl.c b/sysdeps/ieee754/ldbl-128/s_roundl.c
> index d41c9a04dc..8d3f42cd42 100644
> --- a/sysdeps/ieee754/ldbl-128/s_roundl.c
> +++ b/sysdeps/ieee754/ldbl-128/s_roundl.c
> @@ -23,11 +23,14 @@
>  
>  #include <math_private.h>
>  #include <libm-alias-ldouble.h>
> -
> +#include <math-use-builtins.h>
>  
>  _Float128
>  __roundl (_Float128 x)
>  {
> +#if USE_ROUNDL_BUILTIN
> +  return __builtin_roundl (x);
> +#else
>    int32_t j0;
>    uint64_t i1, i0;
>  
> @@ -78,5 +81,6 @@ __roundl (_Float128 x)
>  
>    SET_LDOUBLE_WORDS64 (x, i0, i1);
>    return x;
> +#endif /* USE_ROUNDL_BUILTIN  */
>  }
>  libm_alias_ldouble (__round, round)

Ok.

> diff --git a/sysdeps/s390/fpu/math-use-builtins.h b/sysdeps/s390/fpu/math-use-builtins.h
> index 1d88a2c40f..5838a31c50 100644
> --- a/sysdeps/s390/fpu/math-use-builtins.h
> +++ b/sysdeps/s390/fpu/math-use-builtins.h
> @@ -46,18 +46,24 @@
>  # define USE_TRUNCF_BUILTIN 1
>  # define USE_TRUNCL_BUILTIN 1
>  
> +# define USE_ROUND_BUILTIN 1
> +# define USE_ROUNDF_BUILTIN 1
> +# define USE_ROUNDL_BUILTIN 1
> +
>  # if __GNUC_PREREQ (8, 1)
>  #  define USE_NEARBYINTF128_BUILTIN 1
>  #  define USE_RINTF128_BUILTIN 1
>  #  define USE_FLOORF128_BUILTIN 1
>  #  define USE_CEILF128_BUILTIN 1
>  #  define USE_TRUNCF128_BUILTIN 1
> +#  define USE_ROUNDF128_BUILTIN 1
>  # else
>  #  define USE_NEARBYINTF128_BUILTIN 0
>  #  define USE_RINTF128_BUILTIN 0
>  #  define USE_FLOORF128_BUILTIN 0
>  #  define USE_CEILF128_BUILTIN 0
>  #  define USE_TRUNCF128_BUILTIN 0
> +#  define USE_ROUNDF128_BUILTIN 0
>  # endif
>  
>  #else
> 

Ok.