From: Bruno Haible <bruno@clisp.org>
Date: Sat, 24 Feb 2007 16:31:38 +0000 (+0000)
Subject: Fix a bug with 1.0.
X-Git-Tag: cvs-readonly~989
X-Git-Url: http://erislabs.org.uk/gitweb/?a=commitdiff_plain;h=92f4139cf45cd23105f61e8d7c9e8d06ab719d7e;p=gnulib.git

Fix a bug with 1.0.
---

diff --git a/ChangeLog b/ChangeLog
index ae7b937dd..1c3626cf6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2007-02-24  Bruno Haible  <bruno@clisp.org>
+
+	* lib/frexpl.c (frexpl): Correct return values for x = 1.0L. Don't
+	assume that an exponent fits in 20 bits.
+
 2007-02-24  Jim Meyering  <jim@meyering.net>
 
 	* m4/regex.m4: Update the description of the configure-time option,
diff --git a/lib/frexpl.c b/lib/frexpl.c
index c563fc0c9..f78c4000d 100644
--- a/lib/frexpl.c
+++ b/lib/frexpl.c
@@ -30,11 +30,14 @@
 long double
 frexpl(long double x, int *exp)
 {
-  long double exponents[20], *next;
+  /* Since the exponent is an 'int', it fits in 64 bits.  Therefore the
+     loops are executed no more than 64 times.  */
+  long double exponents[64];
+  long double *next;
   int exponent, bit;
 
   /* Check for zero, nan and infinity. */
-  if (x != x || x + x == x )
+  if (x != x || x + x == x)
     {
       *exp = 0;
       return x;
@@ -44,7 +47,7 @@ frexpl(long double x, int *exp)
     return -frexpl(-x, exp);
 
   exponent = 0;
-  if (x > 1.0)
+  if (x >= 1.0)
     {
       for (next = exponents, exponents[0] = 2.0L, bit = 1;
 	   *next <= x + x;
@@ -90,6 +93,7 @@ main (void)
   x = frexpl(-1.0L / 0.0L, &y); printf ("%.6Lg %d\n", x, y);
   x = frexpl(0.5L, &y); printf ("%.6Lg %d\n", x, y);
   x = frexpl(0.75L, &y); printf ("%.6Lg %d\n", x, y);
+  x = frexpl(1.0L, &y); printf ("%.6Lg %d\n", x, y);
   x = frexpl(3.6L, &y); printf ("%.6Lg %d\n", x, y);
   x = frexpl(17.8L, &y); printf ("%.6Lg %d\n", x, y);
   x = frexpl(8.0L, &y); printf ("%.6Lg %d\n", x, y);