[src/trunk]: src/lib/libm/src fix return value in case of NaN input

[drochner <drochner%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/cb5e60e13c43
branches:  trunk
changeset: 751186:cb5e60e13c43
user:      drochner <drochner%NetBSD.org@localhost>
date:      Wed Jan 27 14:07:41 2010 +0000

description:
fix return value in case of NaN input
(the code also shortcuts the +-inf case, but this was OK before -- it
only avoids an extra check of the mantissa)

diffstat:

 lib/libm/src/s_modf.c  |  4 +++-
 lib/libm/src/s_modff.c |  4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diffs (42 lines):

diff -r 791a5ee289c4 -r cb5e60e13c43 lib/libm/src/s_modf.c
--- a/lib/libm/src/s_modf.c     Wed Jan 27 13:30:45 2010 +0000
+++ b/lib/libm/src/s_modf.c     Wed Jan 27 14:07:41 2010 +0000
@@ -12,7 +12,7 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBM_SCCS) && !defined(lint)
-__RCSID("$NetBSD: s_modf.c,v 1.13 2008/09/28 18:54:55 christos Exp $");
+__RCSID("$NetBSD: s_modf.c,v 1.14 2010/01/27 14:07:41 drochner Exp $");
 #endif
 
 /*
@@ -57,6 +57,8 @@
        } else if (jj0>51) {            /* no fraction part */
            u_int32_t high;
            *iptr = x*one;
+           if (jj0 == 0x400)           /* +-inf or NaN */
+               return 0.0 / x;         /* +-0 or NaN */
            GET_HIGH_WORD(high,x);
            INSERT_WORDS(x,high&0x80000000,0);  /* return +-0 */
            return x;
diff -r 791a5ee289c4 -r cb5e60e13c43 lib/libm/src/s_modff.c
--- a/lib/libm/src/s_modff.c    Wed Jan 27 13:30:45 2010 +0000
+++ b/lib/libm/src/s_modff.c    Wed Jan 27 14:07:41 2010 +0000
@@ -15,7 +15,7 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBM_SCCS) && !defined(lint)
-__RCSID("$NetBSD: s_modff.c,v 1.8 2008/04/25 22:21:53 christos Exp $");
+__RCSID("$NetBSD: s_modff.c,v 1.9 2010/01/27 14:07:41 drochner Exp $");
 #endif
 
 #include "math.h"
@@ -50,6 +50,8 @@
        } else {                        /* no fraction part */
            u_int32_t ix;
            *iptr = x*one;
+           if (jj0 == 0x80)            /* +-inf or NaN */
+               return 0.0 / x;         /* +-0 or NaN */
            GET_FLOAT_WORD(ix,x);
            SET_FLOAT_WORD(x,ix&0x80000000);    /* return +-0 */
            return x;