[src/trunk]: src/include PR 36988: ISO C99 mandates that HUGE_VAL, HUGE_VALF, ...

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

details:   https://anonhg.NetBSD.org/src/rev/cb0fd283daa0
branches:  trunk
changeset: 752318:cb0fd283daa0
user:      joerg <joerg%NetBSD.org@localhost>
date:      Tue Feb 23 00:03:09 2010 +0000

description:
PR 36988: ISO C99 mandates that HUGE_VAL, HUGE_VALF, HUGE_VALL and
INFINITY are constant expressions.

Use the GCC builtins if possible to implement them.

diffstat:

 include/math.h |  15 +++++++++++++--
 1 files changed, 13 insertions(+), 2 deletions(-)

diffs (45 lines):

diff -r 3d90d33b215e -r cb0fd283daa0 include/math.h
--- a/include/math.h    Mon Feb 22 23:52:17 2010 +0000
+++ b/include/math.h    Tue Feb 23 00:03:09 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: math.h,v 1.50 2010/01/11 16:28:39 christos Exp $       */
+/*     $NetBSD: math.h,v 1.51 2010/02/23 00:03:09 joerg Exp $  */
 
 /*
  * ====================================================
@@ -59,8 +59,12 @@
  * ANSI/POSIX
  */
 /* 7.12#3 HUGE_VAL, HUGELF, HUGE_VALL */
+#if __GNUC_PREREQ__(3, 3)
+#define HUGE_VAL       __builtin_huge_val()
+#else
 extern const union __double_u __infinity;
 #define HUGE_VAL       __infinity.__val
+#endif
 
 /*
  * ISO C99
@@ -72,14 +76,21 @@
     ((_XOPEN_SOURCE  - 0) >= 600) || \
     defined(_ISOC99_SOURCE) || defined(_NETBSD_SOURCE)
 /* 7.12#3 HUGE_VAL, HUGELF, HUGE_VALL */
+#if __GNUC_PREREQ__(3, 3)
+#define        HUGE_VALF       __builtin_huge_valf()
+#define        HUGE_VALL       __builtin_huge_vall()
+#else
 extern const union __float_u __infinityf;
 #define        HUGE_VALF       __infinityf.__val
 
 extern const union __long_double_u __infinityl;
 #define        HUGE_VALL       __infinityl.__val
+#endif
 
 /* 7.12#4 INFINITY */
-#ifdef __INFINITY
+#if __GNUC_PREREQ__(3, 3)
+#define        INFINITY        __builtin_inff()
+#elif defined(__INFINITY)
 #define        INFINITY        __INFINITY      /* float constant which overflows */
 #else
 #define        INFINITY        HUGE_VALF       /* positive infinity */