[1/7] ldbl-128ibm-compat: Provide nexttoward functions

Message ID 20200214161051.32579-2-murphyp@linux.vnet.ibm.com
State Committed
Delegated to: Tulio Magno Quites Machado Filho
Headers

Commit Message

Paul E. Murphy Feb. 14, 2020, 4:10 p.m. UTC
  From: "Gabriel F. T. Gomes" <gabriel@inconstante.eti.br>

The functions in the nexttoward family are special, in the sense that
they always have a long double argument, regardless of their suffix
(i.e.: nexttowardf and nexttoward have a long double argument, besides
the float and double arguments).

On top of that, they are also special because nexttoward functions are
not part of the _FloatN API, hence __nexttowardf128 do not exist.

This patch adds 4 new function implementations for the new long double
format:

  __nexttoward_to_ieee128
  __nexttowardf_to_ieee128
  __nexttowardieee128 (as an alias to __nextafterieee128)

Likewise, rename "long double" "_Float128" in shared ldbl-128
files to ensure correct type is used irrespective of ABI
switches.

Thank you to those who helped out with this patch:

 Gabriel F. T. Gomes  <gabriel@inconstante.eti.br>
 Tulio Magno Quites Machado Filho  <tuliom@linux.ibm.com>
---
 sysdeps/ieee754/ldbl-128/s_nexttoward.c       |  4 +-
 sysdeps/ieee754/ldbl-128/s_nexttowardf.c      |  4 +-
 sysdeps/ieee754/ldbl-128ibm-compat/Versions   |  3 ++
 .../ldbl-128ibm-compat/s_nextafterf128.c      | 20 ++++++++++
 .../ldbl-128ibm-compat/s_nexttowardf128.c     | 38 +++++++++++++++++++
 5 files changed, 65 insertions(+), 4 deletions(-)
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/s_nextafterf128.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/s_nexttowardf128.c
  

Comments

Tulio Magno Quites Machado Filho Feb. 27, 2020, 8:16 p.m. UTC | #1
"Paul E. Murphy" <murphyp@linux.vnet.ibm.com> writes:

> From: "Gabriel F. T. Gomes" <gabriel@inconstante.eti.br>
>
> The functions in the nexttoward family are special, in the sense that
> they always have a long double argument, regardless of their suffix
> (i.e.: nexttowardf and nexttoward have a long double argument, besides
> the float and double arguments).
>
> On top of that, they are also special because nexttoward functions are
> not part of the _FloatN API, hence __nexttowardf128 do not exist.
>
> This patch adds 4 new function implementations for the new long double
> format:
>
>   __nexttoward_to_ieee128
>   __nexttowardf_to_ieee128
>   __nexttowardieee128 (as an alias to __nextafterieee128)
>
> Likewise, rename "long double" "_Float128" in shared ldbl-128
> files to ensure correct type is used irrespective of ABI
> switches.

LGTM.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
  
Paul E Murphy Feb. 28, 2020, 2:56 p.m. UTC | #2
On 2/27/20 2:16 PM, Tulio Magno Quites Machado Filho wrote:
> "Paul E. Murphy" <murphyp@linux.vnet.ibm.com> writes:
> 
>> From: "Gabriel F. T. Gomes" <gabriel@inconstante.eti.br>
>>
>> The functions in the nexttoward family are special, in the sense that
>> they always have a long double argument, regardless of their suffix
>> (i.e.: nexttowardf and nexttoward have a long double argument, besides
>> the float and double arguments).
>>
>> On top of that, they are also special because nexttoward functions are
>> not part of the _FloatN API, hence __nexttowardf128 do not exist.
>>
>> This patch adds 4 new function implementations for the new long double
>> format:
>>
>>    __nexttoward_to_ieee128
>>    __nexttowardf_to_ieee128
>>    __nexttowardieee128 (as an alias to __nextafterieee128)
>>
>> Likewise, rename "long double" "_Float128" in shared ldbl-128
>> files to ensure correct type is used irrespective of ABI
>> switches.
> 
> LGTM.
> 
> Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
> 

Committed.  Thanks!
  

Patch

diff --git a/sysdeps/ieee754/ldbl-128/s_nexttoward.c b/sysdeps/ieee754/ldbl-128/s_nexttoward.c
index 6db8b7f15f..e8c25f51b7 100644
--- a/sysdeps/ieee754/ldbl-128/s_nexttoward.c
+++ b/sysdeps/ieee754/ldbl-128/s_nexttoward.c
@@ -31,7 +31,7 @@  static char rcsid[] = "$NetBSD: $";
 #include <math_private.h>
 #include <float.h>
 
-double __nexttoward(double x, long double y)
+double __nexttoward(double x, _Float128 y)
 {
 	int32_t hx,ix;
 	int64_t hy,iy;
@@ -47,7 +47,7 @@  double __nexttoward(double x, long double y)
 	   ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0))
 							    /* y is nan */
 	   return x+y;
-	if((long double) x==y) return y;	/* x=y, return y */
+	if((_Float128) x==y) return y;		/* x=y, return y */
 	if((ix|lx)==0) {			/* x == 0 */
 	    double u;
 	    INSERT_WORDS(x,(uint32_t)((hy>>32)&0x80000000),1);/* return +-minsub */
diff --git a/sysdeps/ieee754/ldbl-128/s_nexttowardf.c b/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
index 7840cb382e..7770c4256d 100644
--- a/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
+++ b/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
@@ -23,7 +23,7 @@  static char rcsid[] = "$NetBSD: $";
 #include <math-barriers.h>
 #include <math_private.h>
 
-float __nexttowardf(float x, long double y)
+float __nexttowardf(float x, _Float128 y)
 {
 	int32_t hx,ix;
 	int64_t hy,iy;
@@ -38,7 +38,7 @@  float __nexttowardf(float x, long double y)
 	   ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0))
 				/* y is nan */
 	   return x+y;
-	if((long double) x==y) return y;	/* x=y, return y */
+	if((_Float128) x==y) return y;		/* x=y, return y */
 	if(ix==0) {				/* x == 0 */
 	    float u;
 	    SET_FLOAT_WORD(x,(uint32_t)((hy>>32)&0x80000000)|1);/* return +-minsub*/
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/Versions b/sysdeps/ieee754/ldbl-128ibm-compat/Versions
index 7224e1ddc7..07e6a5b08a 100644
--- a/sysdeps/ieee754/ldbl-128ibm-compat/Versions
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/Versions
@@ -91,6 +91,9 @@  libm {
     __nearbyintieee128;
     __nextafterieee128;
     __nextdownieee128;
+    __nexttowardf_to_ieee128;
+    __nexttowardieee128;
+    __nexttoward_to_ieee128;
     __nextupieee128;
     __powieee128;
     __remainderieee128;
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/s_nextafterf128.c b/sysdeps/ieee754/ldbl-128ibm-compat/s_nextafterf128.c
new file mode 100644
index 0000000000..cc30ae02d7
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/s_nextafterf128.c
@@ -0,0 +1,20 @@ 
+/* Provide nexttowardl and nextafterl implementations for IEEE long double.
+   Copyright (C) 2020 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
+   <http://www.gnu.org/licenses/>.  */
+#include "../float128/s_nextafterf128.c"
+
+strong_alias (__nextafterieee128, __nexttowardieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/s_nexttowardf128.c b/sysdeps/ieee754/ldbl-128ibm-compat/s_nexttowardf128.c
new file mode 100644
index 0000000000..0b4204cf64
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/s_nexttowardf128.c
@@ -0,0 +1,38 @@ 
+/* Provide nexttoward[|f] implementations for IEEE long double.
+   Copyright (C) 2020 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <float128_private.h>
+
+/* Build nexttoward functions with binary128 format.  */
+#undef weak_alias
+#define weak_alias(from, to)
+#undef libm_alias_ldouble
+#define libm_alias_ldouble(from, to)
+#undef __nexttoward
+#define __nexttoward __nexttoward_to_ieee128
+#include <sysdeps/ieee754/ldbl-128/s_nexttoward.c>
+
+#undef weak_alias
+#define weak_alias(from, to)
+#undef libm_alias_ldouble
+#define libm_alias_ldouble(from, to)
+#undef __nexttowardf
+#define __nexttowardf __nexttowardf_to_ieee128
+#include <sysdeps/ieee754/ldbl-128/s_nexttowardf.c>
+
+#include <libm-alias-ldouble.h>