extend.texi (Other Builtins): Document that __builtin_nan is a compile-time constant only when...

	* doc/extend.texi (Other Builtins): Document that
	__builtin_nan is a compile-time constant only when its argument
	is valid.

From-SVN: r112646

gcc/ChangeLog

+2006-04-03  Geoffrey Keating  <geoffk@apple.com>
+
+	* doc/extend.texi (Other Builtins): Document that
+	__builtin_nan is a compile-time constant only when its argument
+	is valid.
+
 2006-04-03  Adam Nemet  <anemet@caviumnetworks.com>
 
 	* simplify-rtx.c (simplify_unary_operation_1) <TRUNCATE>: When

gcc/doc/extend.texi

@@ -5734,8 +5734,9 @@ is at the least significant bit of the significand.  The number is
 truncated to fit the significand field provided.  The significand is
 forced to be a quiet NaN@.
 
-This function, if given a string literal, is evaluated early enough
-that it is considered a compile-time constant.
+This function, if given a string literal all of which would have been
+consumed by strtol, is evaluated early enough that it is considered a
+compile-time constant.
 @end deftypefn
 
 @deftypefn {Built-in Function} _Decimal32 __builtin_nand32 (const char *str)