Add SNAN, SNANF, SNANL macros.

TS 18661-1 defines SNAN macros for signaling NaN values, suitable for
use in static initializers.  This patch adds them to glibc's <math.h>
(provided you are building with GCC 3.3 or later; no attempt is made
to provide any kind of nonconforming fallback for older compilers
without the __builtin_nans functions).

Tested for x86_64 and x86.

	* math/math.h
	[__GLIBC_USE (IEC_60559_BFP_EXT) && __GNUC_PREREQ (3, 3)] (SNANF):
	New macro.
	[__GLIBC_USE (IEC_60559_BFP_EXT) && __GNUC_PREREQ (3, 3)] (SNAN):
	Likewise.
	[__GLIBC_USE (IEC_60559_BFP_EXT) && __GNUC_PREREQ (3, 3)] (SNANL):
	Likewise.
	* manual/arith.texi (Infinity and NaN): Document SNANF, SNAN and
	SNANL.
	* math/test-double.h (snan_value_MACRO): New macro.
	* math/test-float.h (snan_value_MACRO): Likewise.
	* math/test-ldouble.h (snan_value_MACRO): Likewise.
	* math/libm-test.inc (issignaling_test_data): Add tests of
	snan_value_MACRO.
This commit is contained in:
Joseph Myers 2016-10-28 21:15:26 +00:00
parent 739e14f900
commit f82a4bdb73
8 changed files with 42 additions and 0 deletions

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@ -1,3 +1,20 @@
2016-10-28 Joseph Myers <joseph@codesourcery.com>
* math/math.h
[__GLIBC_USE (IEC_60559_BFP_EXT) && __GNUC_PREREQ (3, 3)] (SNANF):
New macro.
[__GLIBC_USE (IEC_60559_BFP_EXT) && __GNUC_PREREQ (3, 3)] (SNAN):
Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT) && __GNUC_PREREQ (3, 3)] (SNANL):
Likewise.
* manual/arith.texi (Infinity and NaN): Document SNANF, SNAN and
SNANL.
* math/test-double.h (snan_value_MACRO): New macro.
* math/test-float.h (snan_value_MACRO): Likewise.
* math/test-ldouble.h (snan_value_MACRO): Likewise.
* math/libm-test.inc (issignaling_test_data): Add tests of
snan_value_MACRO.
2016-10-28 Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com>
* nptl/pthread_rwlock_unlock.c: Add a comment explaining its

2
NEWS
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@ -51,6 +51,8 @@ Version 2.25
* New <math.h> features are added from TS 18661-1:2014:
- Signaling NaN macros: SNANF, SNAN, SNANL.
- Comparison macros: iseqsig.
- Classification macros: iscanonical, issubnormal, iszero.

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@ -711,6 +711,15 @@ such as by defining @code{_GNU_SOURCE}, and then you must include
@file{math.h}.)
@end deftypevr
@comment math.h
@comment ISO
@deftypevr Macro float SNANF
@deftypevrx Macro double SNAN
@deftypevrx Macro {long double} SNANL
These macros, defined by TS 18661-1:2014, are constant expressions for
signaling NaNs.
@end deftypevr
@w{IEEE 754} also allows for another unusual value: negative zero. This
value is produced when you divide a positive number by negative
infinity, or when a negative result is smaller than the limits of

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@ -8901,6 +8901,8 @@ static const struct test_f_i_data issignaling_test_data[] =
TEST_f_b (issignaling, -qnan_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
TEST_f_b (issignaling, snan_value, 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
TEST_f_b (issignaling, -snan_value, 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
TEST_f_b (issignaling, snan_value_MACRO, 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
TEST_f_b (issignaling, -snan_value_MACRO, 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
};
static void

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@ -45,6 +45,15 @@ __BEGIN_DECLS
# include <bits/nan.h>
#endif /* __USE_ISOC99 */
#if __GLIBC_USE (IEC_60559_BFP_EXT)
/* Signaling NaN macros, if supported. */
# if __GNUC_PREREQ (3, 3)
# define SNANF (__builtin_nansf (""))
# define SNAN (__builtin_nans (""))
# define SNANL (__builtin_nansl (""))
# endif
#endif
/* Get the architecture specific values describing the floating-point
evaluation. The following symbols will get defined:

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@ -27,3 +27,4 @@
#define TYPE_STR "double"
#define LITM(x) x
#define FTOSTR snprintf
#define snan_value_MACRO SNAN

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@ -28,3 +28,4 @@
/* Use the double variants of macro constants. */
#define LITM(x) x
#define FTOSTR snprintf
#define snan_value_MACRO SNANF

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@ -27,3 +27,4 @@
#define LIT(x) (x ## L)
#define LITM(x) x ## l
#define FTOSTR snprintf
#define snan_value_MACRO SNANL