Eggert mods

SCCS-file: difftime.c
SCCS-SID: 7.3

difftime.c

@@ -12,6 +12,13 @@ static char	elsieid[] = "%W%";
 ** Algorithm courtesy Paul Eggert (eggert@twinsun.com).
 */
 
+#ifdef HAVE_LONG_DOUBLE
+	typedef long double long_double;
+#endif /* defined HAVE_LONG_DOUBLE */
+#ifndef HAVE_LONG_DOUBLE
+	typedef double long_double;
+#endif /* !defined HAVE_LONG_DOUBLE */
+
 double
 difftime(time1, time0)
 const time_t	time1;
@@ -22,10 +29,8 @@ const time_t	time0;
 
 	if (sizeof(time_t) < sizeof(double))
 		return (double) time1 - (double) time0;
-#ifdef HAVE_LONG_DOUBLE
-	if (sizeof(time_t) < sizeof(long double))
-		return (long double) time1 - (long double) time0;
-#endif /* defined HAVE_LONG_DOUBLE */
+	if (sizeof(time_t) < sizeof(long_double))
+		return (long_double) time1 - (long_double) time0;
 	if (time1 < time0)
 		return -difftime(time0, time1);
 	/*
@@ -45,14 +50,14 @@ const time_t	time0;
 	** The following expression rounds twice, which means
 	** the result may not be the closest to the true answer.
 	** For example, suppose time_t is 64-bit signed int,
-	** double is IEEE 754 double with default rounding,
+	** long_double is IEEE 754 double with default rounding,
 	** time1 = 9223372036854775807 and time0 = -1536.
 	** Then the true difference is 9223372036854777343,
 	** which rounds to 9223372036854777856
 	** with a total error of 513.
 	** But delta overflows to -9223372036854774273,
 	** which rounds to -9223372036854774784, and correcting
-	** this by subtracting 2 * (double) hibit
+	** this by subtracting 2 * (long_double) hibit
 	** (i.e. by adding 2**64 = 18446744073709551616)
 	** yields 9223372036854776832, which
 	** rounds to 9223372036854775808
@@ -65,5 +70,5 @@ const time_t	time0;
 	** so if time_t is unsigned the "return delta" above
 	** has the same double-rounding problem.
 	*/
-	return delta - 2 * (double) hibit;
+	return delta - 2 * (long_double) hibit;
 }