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Re: [PATCH v2 13/18] Use GCC builtins for copysign functions if desired.
On 09/12/2019 09:46, Stefan Liebler wrote:
> This patch is always using the corresponding GCC builtin for copysignf, copysign,
> and is using the builtin for copysignl, copysignf128 if the USE_FUNCTION_BUILTIN
> macros are defined to one in math-use-builtins.h.
>
> Altough the long double version is enabled by default we still need
> the macro and the alternative implementation as the _Float128 version
> of the builtin is not available with all supported GCC versions.
LGTM, thanks.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> sysdeps/generic/math-use-builtins.h | 9 +++++++++
> sysdeps/ieee754/dbl-64/s_copysign.c | 9 ++-------
> sysdeps/ieee754/float128/float128_private.h | 3 +++
> sysdeps/ieee754/flt-32/s_copysignf.c | 12 ++++--------
> sysdeps/ieee754/ldbl-128/s_copysignl.c | 6 ++++++
> sysdeps/s390/fpu/math-use-builtins.h | 7 +++++++
> 6 files changed, 31 insertions(+), 15 deletions(-)
>
> diff --git a/sysdeps/generic/math-use-builtins.h b/sysdeps/generic/math-use-builtins.h
> index 34ca438a8c..770b54ce61 100644
> --- a/sysdeps/generic/math-use-builtins.h
> +++ b/sysdeps/generic/math-use-builtins.h
> @@ -19,6 +19,8 @@
> #ifndef MATH_USE_BUILTINS_H
> #define MATH_USE_BUILTINS_H 1
>
> +#include <features.h> /* For __GNUC_PREREQ. */
> +
> /* Define these macros to 1 to use __builtin_xyz instead of the
> generic implementation. */
> #define USE_NEARBYINT_BUILTIN 0
> @@ -51,4 +53,11 @@
> #define USE_ROUNDL_BUILTIN 0
> #define USE_ROUNDF128_BUILTIN 0
>
> +#define USE_COPYSIGNL_BUILTIN 1
> +#if __GNUC_PREREQ (7, 0)
> +# define USE_COPYSIGNF128_BUILTIN 1
> +#else
> +# define USE_COPYSIGNF128_BUILTIN 0
> +#endif
> +
> #endif /* math-use-builtins.h */
Ok.
> diff --git a/sysdeps/ieee754/dbl-64/s_copysign.c b/sysdeps/ieee754/dbl-64/s_copysign.c
> index 589b088c95..94025b7854 100644
> --- a/sysdeps/ieee754/dbl-64/s_copysign.c
> +++ b/sysdeps/ieee754/dbl-64/s_copysign.c
> @@ -10,7 +10,7 @@
> * ====================================================
> */
>
> -#if defined(LIBM_SCCS) && !defined(lint)
> +#if defined (LIBM_SCCS) && ! defined (lint)
> static char rcsid[] = "$NetBSD: s_copysign.c,v 1.8 1995/05/10 20:46:57 jtc Exp $";
> #endif
>
> @@ -22,16 +22,11 @@ static char rcsid[] = "$NetBSD: s_copysign.c,v 1.8 1995/05/10 20:46:57 jtc Exp $
>
> #define NO_MATH_REDIRECT
> #include <math.h>
> -#include <math_private.h>
> #include <libm-alias-double.h>
>
> double
> __copysign (double x, double y)
> {
> - uint32_t hx, hy;
> - GET_HIGH_WORD (hx, x);
> - GET_HIGH_WORD (hy, y);
> - SET_HIGH_WORD (x, (hx & 0x7fffffff) | (hy & 0x80000000));
> - return x;
> + return __builtin_copysign (x, y);
> }
> libm_alias_double (__copysign, copysign)
Ok.
> diff --git a/sysdeps/ieee754/float128/float128_private.h b/sysdeps/ieee754/float128/float128_private.h
> index a6c76ce364..7f7f904152 100644
> --- a/sysdeps/ieee754/float128/float128_private.h
> +++ b/sysdeps/ieee754/float128/float128_private.h
> @@ -152,6 +152,8 @@
> #define USE_TRUNCL_BUILTIN USE_TRUNCF128_BUILTIN
> #undef USE_ROUNDL_BUILTIN
> #define USE_ROUNDL_BUILTIN USE_ROUNDF128_BUILTIN
> +#undef USE_COPYSIGNL_BUILTIN
> +#define USE_COPYSIGNL_BUILTIN USE_COPYSIGNF128_BUILTIN
>
> /* IEEE function renames. */
> #define __ieee754_acoshl __ieee754_acoshf128
> @@ -361,6 +363,7 @@
> #define __builtin_ceill __builtin_ceilf128
> #define __builtin_truncl __builtin_truncf128
> #define __builtin_roundl __builtin_roundf128
> +#define __builtin_copysignl __builtin_copysignf128
>
> /* Get the constant suffix from bits/floatn-compat.h. */
> #define L(x) __f128 (x)
Ok.
> diff --git a/sysdeps/ieee754/flt-32/s_copysignf.c b/sysdeps/ieee754/flt-32/s_copysignf.c
> index 77d1d90e92..1c097d313f 100644
> --- a/sysdeps/ieee754/flt-32/s_copysignf.c
> +++ b/sysdeps/ieee754/flt-32/s_copysignf.c
> @@ -13,7 +13,7 @@
> * ====================================================
> */
>
> -#if defined(LIBM_SCCS) && !defined(lint)
> +#if defined (LIBM_SCCS) && ! defined (lint)
> static char rcsid[] = "$NetBSD: s_copysignf.c,v 1.4 1995/05/10 20:46:59 jtc Exp $";
> #endif
>
> @@ -25,15 +25,11 @@ static char rcsid[] = "$NetBSD: s_copysignf.c,v 1.4 1995/05/10 20:46:59 jtc Exp
>
> #define NO_MATH_REDIRECT
> #include <math.h>
> -#include <math_private.h>
> #include <libm-alias-float.h>
>
> -float __copysignf(float x, float y)
> +float
> +__copysignf (float x, float y)
> {
> - uint32_t ix,iy;
> - GET_FLOAT_WORD(ix,x);
> - GET_FLOAT_WORD(iy,y);
> - SET_FLOAT_WORD(x,(ix&0x7fffffff)|(iy&0x80000000));
> - return x;
> + return __builtin_copysignf (x, y);
> }
> libm_alias_float (__copysign, copysign)
Ok.
> diff --git a/sysdeps/ieee754/ldbl-128/s_copysignl.c b/sysdeps/ieee754/ldbl-128/s_copysignl.c
> index a501139f71..848a184524 100644
> --- a/sysdeps/ieee754/ldbl-128/s_copysignl.c
> +++ b/sysdeps/ieee754/ldbl-128/s_copysignl.c
> @@ -27,14 +27,20 @@ static char rcsid[] = "$NetBSD: $";
> #include <math.h>
> #include <math_private.h>
> #include <libm-alias-ldouble.h>
> +#include <math-use-builtins.h>
>
> _Float128 __copysignl(_Float128 x, _Float128 y)
> {
> +#if USE_COPYSIGNL_BUILTIN
> + return __builtin_copysignl (x, y);
> +#else
> + /* Use generic implementation. */
> uint64_t hx,hy;
> GET_LDOUBLE_MSW64(hx,x);
> GET_LDOUBLE_MSW64(hy,y);
> SET_LDOUBLE_MSW64(x,(hx&0x7fffffffffffffffULL)
> |(hy&0x8000000000000000ULL));
> return x;
> +#endif /* ! USE_COPYSIGNL_BUILTIN */
> }
> libm_alias_ldouble (__copysign, copysign)
Ok.
> diff --git a/sysdeps/s390/fpu/math-use-builtins.h b/sysdeps/s390/fpu/math-use-builtins.h
> index 51cb9f91ab..4c4aad2ab5 100644
> --- a/sysdeps/s390/fpu/math-use-builtins.h
> +++ b/sysdeps/s390/fpu/math-use-builtins.h
> @@ -101,4 +101,11 @@
>
> #endif /* ! HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT */
>
> +#define USE_COPYSIGNL_BUILTIN 1
> +#if __GNUC_PREREQ (7, 0)
> +# define USE_COPYSIGNF128_BUILTIN 1
> +#else
> +# define USE_COPYSIGNF128_BUILTIN 0
> +#endif
> +
> #endif /* math-use-builtins.h */
>
Ok.