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author | Paul Eggert <eggert@cs.ucla.edu> | 2005-12-02 00:42:52 +0000 |
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committer | Paul Eggert <eggert@cs.ucla.edu> | 2005-12-02 00:42:52 +0000 |
commit | 76bebf24a531f7019ba6369eb5eafe34c2992882 (patch) | |
tree | 49f0a2466e3dceb957fee8fb154d7cba140f2f87 /lib/intprops.h | |
parent | b3c0bca1f8a793e886889f711a11d4490b8cab85 (diff) | |
download | coreutils-76bebf24a531f7019ba6369eb5eafe34c2992882.tar.xz |
Import from gnulib.
Diffstat (limited to 'lib/intprops.h')
-rw-r--r-- | lib/intprops.h | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/lib/intprops.h b/lib/intprops.h index 65280b159..34f971cba 100644 --- a/lib/intprops.h +++ b/lib/intprops.h @@ -53,12 +53,25 @@ ? (t) -1 \ : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))) +/* Return zero if T can be determined to be an unsigned type. + Otherwise, return 1. + When compiling with GCC, INT_STRLEN_BOUND uses this macro to obtain a + tighter bound. Otherwise, it overestimates the true bound by one byte + when applied to unsigned types of size 2, 4, 16, ... bytes. + The symbol signed_type_or_expr__ is private to this header file. */ +#if __GNUC__ >= 2 +# define signed_type_or_expr__(t) TYPE_SIGNED (__typeof__ (t)) +#else +# define signed_type_or_expr__(t) 1 +#endif + /* Bound on length of the string representing an integer type or expression T. - Subtract 1 for the sign bit if t is signed; log10 (2.0) < 146/485; + Subtract 1 for the sign bit if T is signed; log10 (2.0) < 146/485; add 1 for integer division truncation; add 1 more for a minus sign if needed. */ #define INT_STRLEN_BOUND(t) \ - ((sizeof (t) * CHAR_BIT - 1) * 146 / 485 + 2) + ((sizeof (t) * CHAR_BIT - signed_type_or_expr__ (t)) * 146 / 485 \ + + signed_type_or_expr__ (t) + 1) /* Bound on buffer size needed to represent an integer type or expression T, including the terminating null. */ |