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authorUlrich Drepper <drepper@redhat.com>2004-12-22 19:55:46 +0000
committerUlrich Drepper <drepper@redhat.com>2004-12-22 19:55:46 +0000
commitec8c29dc013a5e0ca3330ce5e4ae989e811491e6 (patch)
tree89ed45fb997421e63457013f492fa91e5b6abb6c /misc/efgcvt_r.c
parent3b7a95fb6b12e8184299378082831d52381a189b (diff)
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(FLOAT_MIN_10_EXP, FLOAT_MIN_10_NORM): Define. (ecvt_r): Special case denormals.
Diffstat (limited to 'misc/efgcvt_r.c')
-rw-r--r--misc/efgcvt_r.c25
1 files changed, 24 insertions, 1 deletions
diff --git a/misc/efgcvt_r.c b/misc/efgcvt_r.c
index ac2a5c4..69cca90 100644
--- a/misc/efgcvt_r.c
+++ b/misc/efgcvt_r.c
@@ -1,5 +1,5 @@
/* Compatibility functions for floating point formatting, reentrant versions.
- Copyright (C) 1995,96,97,98,99,2000,01,02 Free Software Foundation, Inc.
+ Copyright (C) 1995,96,97,98,99,2000,01,02,04 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
@@ -31,6 +31,7 @@
# define FUNC_PREFIX
# define FLOAT_FMT_FLAG
# define FLOAT_NAME_EXT
+# define FLOAT_MIN_10_EXP DBL_MIN_10_EXP
# if DBL_MANT_DIG == 53
# define NDIGIT_MAX 17
# elif DBL_MANT_DIG == 24
@@ -43,6 +44,17 @@
# error "NDIGIT_MAX must be precomputed"
# define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * DBL_MANT_DIG + 1.0)))
# endif
+# if DBL_MIN_10_EXP == -37
+# define FLOAT_MIN_10_NORM 1.0e-37
+# elif DBL_MIN_10_EXP == -307
+# define FLOAT_MIN_10_NORM 1.0e-307
+# elif DBL_MIN_10_EXP == -4931
+# define FLOAT_MIN_10_NORM 1.0e-4931
+# else
+/* libc can't depend on libm. */
+# error "FLOAT_MIN_10_NORM must be precomputed"
+# define FLOAT_MIN_10_NORM exp10 (DBL_MIN_10_EXP)
+# endif
#endif
#define APPEND(a, b) APPEND2 (a, b)
@@ -171,6 +183,17 @@ APPEND (FUNC_PREFIX, ecvt_r) (value, ndigit, decpt, sign, buf, len)
d = -value;
else
d = value;
+ /* For denormalized numbers the d < 1.0 case below won't work,
+ as f can overflow to +Inf. */
+ if (d < FLOAT_MIN_10_NORM)
+ {
+ value /= FLOAT_MIN_10_NORM;
+ if (value < 0.0)
+ d = -value;
+ else
+ d = value;
+ exponent += FLOAT_MIN_10_EXP;
+ }
if (d < 1.0)
{
do