From 735a36828f349419379f15e942bfdf0c532d58eb Mon Sep 17 00:00:00 2001
From: Stefan Liebler <stli@linux.ibm.com>
Date: Wed, 11 Dec 2019 15:09:18 +0100
Subject: [PATCH 07/28] Use GCC builtins for nearbyint functions if desired.
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.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit ae3577f607b50bf3ce9b0877e43ad2508c9da61b)
Note: The TWO52 constants are now located in # ! USE_NEARBYINT_BUILTIN
---
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 */
diff --git a/sysdeps/ieee754/dbl-64/s_nearbyint.c b/sysdeps/ieee754/dbl-64/s_nearbyint.c
index 903121d456..6b9f44dc8d 100644
--- a/sysdeps/ieee754/dbl-64/s_nearbyint.c
+++ b/sysdeps/ieee754/dbl-64/s_nearbyint.c
@@ -29,16 +29,20 @@ static char rcsid[] = "$NetBSD: s_rint.c,v 1.8 1995/05/10 20:48:04 jtc Exp $";
#include <math-barriers.h>
#include <math_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;
int32_t i0, j0, sx;
double w, t;
@@ -72,5 +76,6 @@ __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 9dd15601e6..0bf6e8dee2 100644
--- a/sysdeps/ieee754/float128/float128_private.h
+++ b/sysdeps/ieee754/float128/float128_private.h
@@ -138,6 +138,9 @@
#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
@@ -339,6 +342,7 @@
/* 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 4dfe491f27..438dcae8cc 100644
--- a/sysdeps/ieee754/flt-32/s_nearbyintf.c
+++ b/sysdeps/ieee754/flt-32/s_nearbyintf.c
@@ -20,16 +20,20 @@
#include <math-barriers.h>
#include <math_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;
@@ -57,5 +61,6 @@ __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 */
--
2.18.2