From: Jim Meyering <jim@meyering.net>
Date: Sat, 17 Mar 2001 08:50:51 +0000 (+0000)
Subject: (INT_STRLEN_BOUND): New macro.
X-Git-Tag: FILEUTILS-4_0_42~21
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=9f9610d9833dd394269443111e4e612c55cdd820;p=thirdparty%2Fcoreutils.git

(INT_STRLEN_BOUND): New macro.
---

diff --git a/src/sys2.h b/src/sys2.h
index 2ed46b16b7..48af648c30 100644
--- a/src/sys2.h
+++ b/src/sys2.h
@@ -488,6 +488,11 @@ enum
 			      ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0))
 #define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t)))
 
+/* Upper bound on the string length of an integer converted to string.
+   302 / 1000 is ceil (log10 (2.0)).  Subtract 1 for the sign bit;
+   add 1 for integer division truncation; add 1 more for a minus sign.  */
+#define INT_STRLEN_BOUND(t) ((sizeof (t) * CHAR_BIT - 1) * 302 / 1000 + 2)
+
 #ifndef CHAR_MIN
 # define CHAR_MIN TYPE_MINIMUM (char)
 #endif