diff options
Diffstat (limited to 'lib/isnan.c')
| -rw-r--r-- | lib/isnan.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/lib/isnan.c b/lib/isnan.c index d95e4bac..878c1804 100644 --- a/lib/isnan.c +++ b/lib/isnan.c @@ -1,5 +1,5 @@ /* Test for NaN that does not need libm. - Copyright (C) 2007-2013 Free Software Foundation, Inc. + Copyright (C) 2007-2014 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -79,10 +79,21 @@ extern int rpl_isnanf (float x); ((sizeof (DOUBLE) + sizeof (unsigned int) - 1) / sizeof (unsigned int)) typedef union { DOUBLE value; unsigned int word[NWORDS]; } memory_double; +/* Most hosts nowadays use IEEE floating point, so they use IEC 60559 + representations, have infinities and NaNs, and do not trap on + exceptions. Define IEEE_FLOATING_POINT if this host is one of the + typical ones. The C11 macro __STDC_IEC_559__ is close to what is + wanted here, but is not quite right because this file does not require + all the features of C11 Annex F (and does not require C11 at all, + for that matter). */ + +#define IEEE_FLOATING_POINT (FLT_RADIX == 2 && FLT_MANT_DIG == 24 \ + && FLT_MIN_EXP == -125 && FLT_MAX_EXP == 128) + int FUNC (DOUBLE x) { -#ifdef KNOWN_EXPBIT0_LOCATION +#if defined KNOWN_EXPBIT0_LOCATION && IEEE_FLOATING_POINT # if defined USE_LONG_DOUBLE && ((defined __ia64 && LDBL_MANT_DIG == 64) || (defined __x86_64__ || defined __amd64__) || (defined __i386 || defined __i386__ || defined _I386 || defined _M_IX86 || defined _X86_)) && !HAVE_SAME_LONG_DOUBLE_AS_DOUBLE /* Special CPU dependent code is needed to treat bit patterns outside the IEEE 754 specification (such as Pseudo-NaNs, Pseudo-Infinities, @@ -153,8 +164,9 @@ FUNC (DOUBLE x) } # endif #else - /* The configuration did not find sufficient information. Give up about - the signaling NaNs, handle only the quiet NaNs. */ + /* The configuration did not find sufficient information, or does + not use IEEE floating point. Give up about the signaling NaNs; + handle only the quiet NaNs. */ if (x == x) { # if defined USE_LONG_DOUBLE && ((defined __ia64 && LDBL_MANT_DIG == 64) || (defined __x86_64__ || defined __amd64__) || (defined __i386 || defined __i386__ || defined _I386 || defined _M_IX86 || defined _X86_)) && !HAVE_SAME_LONG_DOUBLE_AS_DOUBLE |