From: Stefan Liebler <stli@linux.ibm.com>
To: Joseph Myers <joseph@codesourcery.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH 13/13] Use GCC builtins for copysign functions if desired.
Date: Wed, 04 Dec 2019 16:34:00 -0000 [thread overview]
Message-ID: <b9338b4d-b058-5975-74e9-1116c864131f@linux.ibm.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1912041320080.19057@digraph.polyomino.org.uk>
[-- Attachment #1: Type: text/plain, Size: 1008 bytes --]
On 12/4/19 2:20 PM, Joseph Myers wrote:
> On Wed, 4 Dec 2019, Stefan Liebler wrote:
>
>>> I think they can all be 1, given that IBM long double has its own
>>> implementation. Except that you shouldn't need the indirection through
>>> these macros at all. Just use __builtin_copysign etc. directly in the
>>> implementations (other than IBM long double), unconditionally, the same
>>> way that sysdeps/ieee754/dbl-64/s_fabs.c uses __builtin_fabs directly
>>> without such macros being needed.
>>>
>>
>> Okay. I've set them to 1 and also used build-many-glibcs.py and had a look
>> into the s_copysign*.os files. There is no function call to copysign* itself.
>
> I think we should handle this like fabs and not have the macros at all,
> just call __builtin_copysign etc. unconditionally.
>
Okay. Then I've removed the macros for float and double and call the
builtins unconditionally.
But I still need the long double version as the f128 builtin is not
available with every GCC version.
Bye,
Stefan
[-- Attachment #2: 0013-Use-GCC-builtins-for-copysign-functions-if-desired.patch --]
[-- Type: text/x-patch, Size: 6038 bytes --]
commit 105b38cfc6d03772b4fe913dc1db9f56b4045bfb
Author: Stefan Liebler <stli@linux.ibm.com>
Date: Mon Dec 2 15:32:44 2019 +0100
Use GCC builtins for copysign functions if desired.
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.
diff --git a/sysdeps/generic/math-use-builtins.h b/sysdeps/generic/math-use-builtins.h
index 34ca438a8c..ca44926dc6 100644
--- a/sysdeps/generic/math-use-builtins.h
+++ b/sysdeps/generic/math-use-builtins.h
@@ -51,4 +51,7 @@
#define USE_ROUNDL_BUILTIN 0
#define USE_ROUNDF128_BUILTIN 0
+#define USE_COPYSIGNL_BUILTIN 1
+#define USE_COPYSIGNF128_BUILTIN 0
+
#endif /* math-use-builtins.h */
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)
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)
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)
diff --git a/sysdeps/ieee754/ldbl-128/s_copysignl.c b/sysdeps/ieee754/ldbl-128/s_copysignl.c
index a501139f71..6095b7fc73 100644
--- a/sysdeps/ieee754/ldbl-128/s_copysignl.c
+++ b/sysdeps/ieee754/ldbl-128/s_copysignl.c
@@ -13,7 +13,9 @@
* ====================================================
*/
-#if defined(LIBM_SCCS) && !defined(lint)
+#include <math-use-builtins.h>
+
+#if ! USE_COPYSIGNL_BUILTIN && defined (LIBM_SCCS) && ! defined (lint)
static char rcsid[] = "$NetBSD: $";
#endif
@@ -28,13 +30,18 @@ static char rcsid[] = "$NetBSD: $";
#include <math_private.h>
#include <libm-alias-ldouble.h>
-_Float128 __copysignl(_Float128 x, _Float128 y)
+_Float128
+__copysignl (_Float128 x, _Float128 y)
{
- uint64_t hx,hy;
- GET_LDOUBLE_MSW64(hx,x);
- GET_LDOUBLE_MSW64(hy,y);
- SET_LDOUBLE_MSW64(x,(hx&0x7fffffffffffffffULL)
- |(hy&0x8000000000000000ULL));
- return x;
+#if USE_COPYSIGNL_BUILTIN
+ return __builtin_copysignl (x, y);
+#else
+ 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
}
libm_alias_ldouble (__copysign, copysign)
diff --git a/sysdeps/s390/fpu/math-use-builtins.h b/sysdeps/s390/fpu/math-use-builtins.h
index 5838a31c50..cd722ad884 100644
--- a/sysdeps/s390/fpu/math-use-builtins.h
+++ b/sysdeps/s390/fpu/math-use-builtins.h
@@ -50,6 +50,11 @@
# define USE_ROUNDF_BUILTIN 1
# define USE_ROUNDL_BUILTIN 1
+/* GCC emits the z9-ec zarch "copy sign" instruction for these
+ builtins if build with at least --march=z196 -mzarch.
+ Note: z196 is no typo but a bug in GCC! */
+# define USE_COPYSIGNL_BUILTIN 1
+
# if __GNUC_PREREQ (8, 1)
# define USE_NEARBYINTF128_BUILTIN 1
# define USE_RINTF128_BUILTIN 1
@@ -57,6 +62,7 @@
# define USE_CEILF128_BUILTIN 1
# define USE_TRUNCF128_BUILTIN 1
# define USE_ROUNDF128_BUILTIN 1
+# define USE_COPYSIGNF128_BUILTIN 1
# else
# define USE_NEARBYINTF128_BUILTIN 0
# define USE_RINTF128_BUILTIN 0
@@ -64,6 +70,7 @@
# define USE_CEILF128_BUILTIN 0
# define USE_TRUNCF128_BUILTIN 0
# define USE_ROUNDF128_BUILTIN 0
+# define USE_COPYSIGNF128_BUILTIN 0
# endif
#else
next prev parent reply other threads:[~2019-12-04 16:34 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-02 14:46 [PATCH 00/13] Use GCC builtins for some math " Stefan Liebler
2019-12-02 14:46 ` [PATCH 01/13] Always use wordsize-64 version of s_nearbyint.c Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 07/13] Use GCC builtins for nearbyint functions if desired Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 05/13] Always use wordsize-64 version of s_trunc.c Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 03/13] Always use wordsize-64 version of s_floor.c Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 02/13] Always use wordsize-64 version of s_rint.c Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 09/13] Use GCC builtins for floor functions if desired Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 08/13] Use GCC builtins for rint " Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 15:10 ` [PATCH 11/13] Use GCC builtins for trunc " Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 15:15 ` [PATCH 04/13] Always use wordsize-64 version of s_ceil.c Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 15:18 ` [PATCH 10/13] Use GCC builtins for ceil functions if desired Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 15:46 ` [PATCH 06/13] Always use wordsize-64 version of s_round.c Stefan Liebler
2019-12-05 20:40 ` Adhemerval Zanella
2019-12-02 15:50 ` [PATCH 12/13] Use GCC builtins for round functions if desired Stefan Liebler
2019-12-05 20:41 ` Adhemerval Zanella
2019-12-02 15:52 ` [PATCH 13/13] Use GCC builtins for copysign " Stefan Liebler
2019-12-02 21:00 ` Joseph Myers
2019-12-03 8:27 ` Stefan Liebler
2019-12-03 16:51 ` Joseph Myers
2019-12-04 13:15 ` Stefan Liebler
2019-12-04 13:20 ` Joseph Myers
2019-12-04 16:34 ` Stefan Liebler [this message]
2019-12-04 20:43 ` Joseph Myers
2019-12-05 15:40 ` Stefan Liebler
2019-12-09 12:58 ` [PATCH 00/13] Use GCC builtins for some math " Stefan Liebler
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=b9338b4d-b058-5975-74e9-1116c864131f@linux.ibm.com \
--to=stli@linux.ibm.com \
--cc=joseph@codesourcery.com \
--cc=libc-alpha@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).