Patchwork [v2,07/18] Use GCC builtins for nearbyint functions if desired.

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Submitter Stefan Liebler
Date Dec. 9, 2019, 12:45 p.m.
Message ID <1575895568-26473-8-git-send-email-stli@linux.ibm.com>
Download mbox | patch
Permalink /patch/36652/
State Committed
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Comments

Stefan Liebler - Dec. 9, 2019, 12:45 p.m.
This patch is using the corresponding GCC builtin for nearbyintf, nearbyint,
nearbintl and nearbyintf128 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.  The code of the generic
implementation is not changed.
---
 sysdeps/generic/math-use-builtins.h         | 29 ++++++++++++
 sysdeps/ieee754/dbl-64/s_nearbyint.c        | 17 ++++---
 sysdeps/ieee754/float128/float128_private.h |  4 ++
 sysdeps/ieee754/flt-32/s_nearbyintf.c       | 17 ++++---
 sysdeps/ieee754/ldbl-128/s_nearbyintl.c     | 17 ++++---
 sysdeps/s390/fpu/math-use-builtins.h        | 49 +++++++++++++++++++++
 6 files changed, 115 insertions(+), 18 deletions(-)
 create mode 100644 sysdeps/generic/math-use-builtins.h
 create mode 100644 sysdeps/s390/fpu/math-use-builtins.h
Adhemerval Zanella Netto - Dec. 10, 2019, 7:15 p.m.
On 09/12/2019 09:45, Stefan Liebler wrote:
> This patch is using the corresponding GCC builtin for nearbyintf, nearbyint,
> nearbintl and nearbyintf128 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.  The code of the generic
> implementation is not changed.

LGTM, thanks.

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

> ---
>  sysdeps/generic/math-use-builtins.h         | 29 ++++++++++++
>  sysdeps/ieee754/dbl-64/s_nearbyint.c        | 17 ++++---
>  sysdeps/ieee754/float128/float128_private.h |  4 ++
>  sysdeps/ieee754/flt-32/s_nearbyintf.c       | 17 ++++---
>  sysdeps/ieee754/ldbl-128/s_nearbyintl.c     | 17 ++++---
>  sysdeps/s390/fpu/math-use-builtins.h        | 49 +++++++++++++++++++++
>  6 files changed, 115 insertions(+), 18 deletions(-)
>  create mode 100644 sysdeps/generic/math-use-builtins.h
>  create mode 100644 sysdeps/s390/fpu/math-use-builtins.h
> 
> diff --git a/sysdeps/generic/math-use-builtins.h b/sysdeps/generic/math-use-builtins.h
> new file mode 100644
> index 0000000000..e12490ed41
> --- /dev/null
> +++ b/sysdeps/generic/math-use-builtins.h
> @@ -0,0 +1,29 @@
> +/* Using math gcc builtins instead of generic implementation.  Generic version.
> +   Copyright (C) 2019 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#ifndef MATH_USE_BUILTINS_H
> +#define MATH_USE_BUILTINS_H	1
> +
> +/* Define these macros to 1 to use __builtin_xyz instead of the
> +   generic implementation.  */
> +#define USE_NEARBYINT_BUILTIN 0
> +#define USE_NEARBYINTF_BUILTIN 0
> +#define USE_NEARBYINTL_BUILTIN 0
> +#define USE_NEARBYINTF128_BUILTIN 0
> +
> +#endif /* math-use-builtins.h */

Ok.

> diff --git a/sysdeps/ieee754/dbl-64/s_nearbyint.c b/sysdeps/ieee754/dbl-64/s_nearbyint.c
> index c261885c5a..2deaeb2568 100644
> --- a/sysdeps/ieee754/dbl-64/s_nearbyint.c
> +++ b/sysdeps/ieee754/dbl-64/s_nearbyint.c
> @@ -26,16 +26,20 @@
>  #include <math_private.h>
>  #include <fenv_private.h>
>  #include <libm-alias-double.h>
> -
> -static const double
> -TWO52[2] = {
> -	    4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
> -	    -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
> -};
> +#include <math-use-builtins.h>
>  
>  double
>  __nearbyint (double x)
>  {
> +#if USE_NEARBYINT_BUILTIN
> +  return __builtin_nearbyint (x);
> +#else
> +  /* Use generic implementation.  */
> +  static const double
> +    TWO52[2] = {
> +		4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
> +		-4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
> +  };
>    fenv_t env;
>    int64_t i0, sx;
>    int32_t j0;
> @@ -67,5 +71,6 @@ __nearbyint (double x)
>    math_force_eval (t);
>    libc_fesetenv (&env);
>    return t;
> +#endif /* ! USE_NEARBYINT_BUILTIN  */
>  }
>  libm_alias_double (__nearbyint, nearbyint)

Ok.

> diff --git a/sysdeps/ieee754/float128/float128_private.h b/sysdeps/ieee754/float128/float128_private.h
> index 4e31ef365b..e96986a968 100644
> --- a/sysdeps/ieee754/float128/float128_private.h
> +++ b/sysdeps/ieee754/float128/float128_private.h
> @@ -139,6 +139,9 @@
>  #undef libm_alias_double_ldouble
>  #define libm_alias_double_ldouble(func) libm_alias_float64_float128 (func)
>  
> +#include <math-use-builtins.h>
> +#undef USE_NEARBYINTL_BUILTIN
> +#define USE_NEARBYINTL_BUILTIN USE_NEARBYINTF128_BUILTIN
>  
>  /* IEEE function renames.  */
>  #define __ieee754_acoshl __ieee754_acoshf128
> @@ -342,6 +345,7 @@
>  /* Builtin renames.  */
>  #define __builtin_copysignl __builtin_copysignf128
>  #define __builtin_signbitl __builtin_signbit
> +#define __builtin_nearbyintl __builtin_nearbyintf128
>  
>  /* Get the constant suffix from bits/floatn-compat.h.  */
>  #define L(x) __f128 (x)

Ok.

> diff --git a/sysdeps/ieee754/flt-32/s_nearbyintf.c b/sysdeps/ieee754/flt-32/s_nearbyintf.c
> index acedf34c90..b37e003e12 100644
> --- a/sysdeps/ieee754/flt-32/s_nearbyintf.c
> +++ b/sysdeps/ieee754/flt-32/s_nearbyintf.c
> @@ -21,16 +21,20 @@
>  #include <math_private.h>
>  #include <fenv_private.h>
>  #include <libm-alias-float.h>
> -
> -static const float
> -TWO23[2]={
> -  8.3886080000e+06, /* 0x4b000000 */
> - -8.3886080000e+06, /* 0xcb000000 */
> -};
> +#include <math-use-builtins.h>
>  
>  float
>  __nearbyintf(float x)
>  {
> +#if USE_NEARBYINTF_BUILTIN
> +  return __builtin_nearbyintf (x);
> +#else
> +  /* Use generic implementation.  */
> +  static const float
> +    TWO23[2] = {
> +		8.3886080000e+06, /* 0x4b000000 */
> +		-8.3886080000e+06, /* 0xcb000000 */
> +  };
>  	fenv_t env;
>  	int32_t i0,j0,sx;
>  	float w,t;
> @@ -58,5 +62,6 @@ __nearbyintf(float x)
>  	math_force_eval (t);
>  	libc_fesetenvf (&env);
>  	return t;
> +#endif /* ! USE_NEARBYINT_BUILTIN  */
>  }
>  libm_alias_float (__nearbyint, nearbyint)

Ok.

> diff --git a/sysdeps/ieee754/ldbl-128/s_nearbyintl.c b/sysdeps/ieee754/ldbl-128/s_nearbyintl.c
> index f044cb4334..a4ad8e82e5 100644
> --- a/sysdeps/ieee754/ldbl-128/s_nearbyintl.c
> +++ b/sysdeps/ieee754/ldbl-128/s_nearbyintl.c
> @@ -28,15 +28,19 @@
>  #include <math-barriers.h>
>  #include <math_private.h>
>  #include <libm-alias-ldouble.h>
> -
> -static const _Float128
> -TWO112[2]={
> -  L(5.19229685853482762853049632922009600E+33), /* 0x406F000000000000, 0 */
> - L(-5.19229685853482762853049632922009600E+33)  /* 0xC06F000000000000, 0 */
> -};
> +#include <math-use-builtins.h>
>  
>  _Float128 __nearbyintl(_Float128 x)
>  {
> +#if USE_NEARBYINTL_BUILTIN
> +  return __builtin_nearbyintl (x);
> +#else
> +  /* Use generic implementation.  */
> +  static const _Float128
> +    TWO112[2] = {
> +		 L(5.19229685853482762853049632922009600E+33), /* 0x406F000000000000, 0 */
> +		 L(-5.19229685853482762853049632922009600E+33)  /* 0xC06F000000000000, 0 */
> +  };
>  	fenv_t env;
>  	int64_t i0,j0,sx;
>  	uint64_t i1 __attribute__ ((unused));
> @@ -65,5 +69,6 @@ _Float128 __nearbyintl(_Float128 x)
>  	math_force_eval (t);
>  	fesetenv (&env);
>  	return t;
> +#endif /* ! USE_NEARBYINTL_BUILTIN  */
>  }
>  libm_alias_ldouble (__nearbyint, nearbyint)

Ok.

> diff --git a/sysdeps/s390/fpu/math-use-builtins.h b/sysdeps/s390/fpu/math-use-builtins.h
> new file mode 100644
> index 0000000000..7abbfb3b50
> --- /dev/null
> +++ b/sysdeps/s390/fpu/math-use-builtins.h
> @@ -0,0 +1,49 @@
> +/* Using math gcc builtins instead of generic implementation.  s390/s390x version.
> +   Copyright (C) 2019 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#ifndef MATH_USE_BUILTINS_S390_H
> +#define MATH_USE_BUILTINS_S390_H	1
> +
> +#ifdef HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT
> +
> +# include <features.h> /* For __GNUC_PREREQ.  */
> +
> +/* GCC emits the z196 zarch "load fp integer" instructions for these
> +   builtins if build with at least --march=z196 -mzarch.  Otherwise a
> +   function call to libc is emitted.  */
> +# define USE_NEARBYINT_BUILTIN 1
> +# define USE_NEARBYINTF_BUILTIN 1
> +# define USE_NEARBYINTL_BUILTIN 1
> +
> +# if __GNUC_PREREQ (8, 0)
> +#  define USE_NEARBYINTF128_BUILTIN 1
> +# else
> +#  define USE_NEARBYINTF128_BUILTIN 0
> +# endif
> +
> +#else
> +
> +/* Disable the builtins if we do not have the z196 zarch instructions.  */
> +# define USE_NEARBYINT_BUILTIN 0
> +# define USE_NEARBYINTF_BUILTIN 0
> +# define USE_NEARBYINTL_BUILTIN 0
> +# define USE_NEARBYINTF128_BUILTIN 0
> +
> +#endif /* ! HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT  */
> +
> +#endif /* math-use-builtins.h */
> 

Ok.

Patch

diff --git a/sysdeps/generic/math-use-builtins.h b/sysdeps/generic/math-use-builtins.h
new file mode 100644
index 0000000000..e12490ed41
--- /dev/null
+++ b/sysdeps/generic/math-use-builtins.h
@@ -0,0 +1,29 @@ 
+/* Using math gcc builtins instead of generic implementation.  Generic version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef MATH_USE_BUILTINS_H
+#define MATH_USE_BUILTINS_H	1
+
+/* Define these macros to 1 to use __builtin_xyz instead of the
+   generic implementation.  */
+#define USE_NEARBYINT_BUILTIN 0
+#define USE_NEARBYINTF_BUILTIN 0
+#define USE_NEARBYINTL_BUILTIN 0
+#define USE_NEARBYINTF128_BUILTIN 0
+
+#endif /* math-use-builtins.h */
diff --git a/sysdeps/ieee754/dbl-64/s_nearbyint.c b/sysdeps/ieee754/dbl-64/s_nearbyint.c
index c261885c5a..2deaeb2568 100644
--- a/sysdeps/ieee754/dbl-64/s_nearbyint.c
+++ b/sysdeps/ieee754/dbl-64/s_nearbyint.c
@@ -26,16 +26,20 @@ 
 #include <math_private.h>
 #include <fenv_private.h>
 #include <libm-alias-double.h>
-
-static const double
-TWO52[2] = {
-	    4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
-	    -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
-};
+#include <math-use-builtins.h>
 
 double
 __nearbyint (double x)
 {
+#if USE_NEARBYINT_BUILTIN
+  return __builtin_nearbyint (x);
+#else
+  /* Use generic implementation.  */
+  static const double
+    TWO52[2] = {
+		4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
+		-4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
+  };
   fenv_t env;
   int64_t i0, sx;
   int32_t j0;
@@ -67,5 +71,6 @@  __nearbyint (double x)
   math_force_eval (t);
   libc_fesetenv (&env);
   return t;
+#endif /* ! USE_NEARBYINT_BUILTIN  */
 }
 libm_alias_double (__nearbyint, nearbyint)
diff --git a/sysdeps/ieee754/float128/float128_private.h b/sysdeps/ieee754/float128/float128_private.h
index 4e31ef365b..e96986a968 100644
--- a/sysdeps/ieee754/float128/float128_private.h
+++ b/sysdeps/ieee754/float128/float128_private.h
@@ -139,6 +139,9 @@ 
 #undef libm_alias_double_ldouble
 #define libm_alias_double_ldouble(func) libm_alias_float64_float128 (func)
 
+#include <math-use-builtins.h>
+#undef USE_NEARBYINTL_BUILTIN
+#define USE_NEARBYINTL_BUILTIN USE_NEARBYINTF128_BUILTIN
 
 /* IEEE function renames.  */
 #define __ieee754_acoshl __ieee754_acoshf128
@@ -342,6 +345,7 @@ 
 /* Builtin renames.  */
 #define __builtin_copysignl __builtin_copysignf128
 #define __builtin_signbitl __builtin_signbit
+#define __builtin_nearbyintl __builtin_nearbyintf128
 
 /* Get the constant suffix from bits/floatn-compat.h.  */
 #define L(x) __f128 (x)
diff --git a/sysdeps/ieee754/flt-32/s_nearbyintf.c b/sysdeps/ieee754/flt-32/s_nearbyintf.c
index acedf34c90..b37e003e12 100644
--- a/sysdeps/ieee754/flt-32/s_nearbyintf.c
+++ b/sysdeps/ieee754/flt-32/s_nearbyintf.c
@@ -21,16 +21,20 @@ 
 #include <math_private.h>
 #include <fenv_private.h>
 #include <libm-alias-float.h>
-
-static const float
-TWO23[2]={
-  8.3886080000e+06, /* 0x4b000000 */
- -8.3886080000e+06, /* 0xcb000000 */
-};
+#include <math-use-builtins.h>
 
 float
 __nearbyintf(float x)
 {
+#if USE_NEARBYINTF_BUILTIN
+  return __builtin_nearbyintf (x);
+#else
+  /* Use generic implementation.  */
+  static const float
+    TWO23[2] = {
+		8.3886080000e+06, /* 0x4b000000 */
+		-8.3886080000e+06, /* 0xcb000000 */
+  };
 	fenv_t env;
 	int32_t i0,j0,sx;
 	float w,t;
@@ -58,5 +62,6 @@  __nearbyintf(float x)
 	math_force_eval (t);
 	libc_fesetenvf (&env);
 	return t;
+#endif /* ! USE_NEARBYINT_BUILTIN  */
 }
 libm_alias_float (__nearbyint, nearbyint)
diff --git a/sysdeps/ieee754/ldbl-128/s_nearbyintl.c b/sysdeps/ieee754/ldbl-128/s_nearbyintl.c
index f044cb4334..a4ad8e82e5 100644
--- a/sysdeps/ieee754/ldbl-128/s_nearbyintl.c
+++ b/sysdeps/ieee754/ldbl-128/s_nearbyintl.c
@@ -28,15 +28,19 @@ 
 #include <math-barriers.h>
 #include <math_private.h>
 #include <libm-alias-ldouble.h>
-
-static const _Float128
-TWO112[2]={
-  L(5.19229685853482762853049632922009600E+33), /* 0x406F000000000000, 0 */
- L(-5.19229685853482762853049632922009600E+33)  /* 0xC06F000000000000, 0 */
-};
+#include <math-use-builtins.h>
 
 _Float128 __nearbyintl(_Float128 x)
 {
+#if USE_NEARBYINTL_BUILTIN
+  return __builtin_nearbyintl (x);
+#else
+  /* Use generic implementation.  */
+  static const _Float128
+    TWO112[2] = {
+		 L(5.19229685853482762853049632922009600E+33), /* 0x406F000000000000, 0 */
+		 L(-5.19229685853482762853049632922009600E+33)  /* 0xC06F000000000000, 0 */
+  };
 	fenv_t env;
 	int64_t i0,j0,sx;
 	uint64_t i1 __attribute__ ((unused));
@@ -65,5 +69,6 @@  _Float128 __nearbyintl(_Float128 x)
 	math_force_eval (t);
 	fesetenv (&env);
 	return t;
+#endif /* ! USE_NEARBYINTL_BUILTIN  */
 }
 libm_alias_ldouble (__nearbyint, nearbyint)
diff --git a/sysdeps/s390/fpu/math-use-builtins.h b/sysdeps/s390/fpu/math-use-builtins.h
new file mode 100644
index 0000000000..7abbfb3b50
--- /dev/null
+++ b/sysdeps/s390/fpu/math-use-builtins.h
@@ -0,0 +1,49 @@ 
+/* Using math gcc builtins instead of generic implementation.  s390/s390x version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef MATH_USE_BUILTINS_S390_H
+#define MATH_USE_BUILTINS_S390_H	1
+
+#ifdef HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT
+
+# include <features.h> /* For __GNUC_PREREQ.  */
+
+/* GCC emits the z196 zarch "load fp integer" instructions for these
+   builtins if build with at least --march=z196 -mzarch.  Otherwise a
+   function call to libc is emitted.  */
+# define USE_NEARBYINT_BUILTIN 1
+# define USE_NEARBYINTF_BUILTIN 1
+# define USE_NEARBYINTL_BUILTIN 1
+
+# if __GNUC_PREREQ (8, 0)
+#  define USE_NEARBYINTF128_BUILTIN 1
+# else
+#  define USE_NEARBYINTF128_BUILTIN 0
+# endif
+
+#else
+
+/* Disable the builtins if we do not have the z196 zarch instructions.  */
+# define USE_NEARBYINT_BUILTIN 0
+# define USE_NEARBYINTF_BUILTIN 0
+# define USE_NEARBYINTL_BUILTIN 0
+# define USE_NEARBYINTF128_BUILTIN 0
+
+#endif /* ! HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT  */
+
+#endif /* math-use-builtins.h */