Module Name: src
Committed By: christos
Date: Sat Aug 27 09:11:56 UTC 2016
Modified Files:
src/lib/libc/compat/gen: compat_ldexp_ieee754.c
Log Message:
detect overflow in oldexp + newexp
To generate a diff of this commit:
cvs rdiff -u -r1.5 -r1.6 src/lib/libc/compat/gen/compat_ldexp_ieee754.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/libc/compat/gen/compat_ldexp_ieee754.c
diff -u src/lib/libc/compat/gen/compat_ldexp_ieee754.c:1.5 src/lib/libc/compat/gen/compat_ldexp_ieee754.c:1.6
--- src/lib/libc/compat/gen/compat_ldexp_ieee754.c:1.5 Fri Apr 23 15:04:54 2010
+++ src/lib/libc/compat/gen/compat_ldexp_ieee754.c Sat Aug 27 05:11:56 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: compat_ldexp_ieee754.c,v 1.5 2010/04/23 19:04:54 drochner Exp $ */
+/* $NetBSD: compat_ldexp_ieee754.c,v 1.6 2016/08/27 09:11:56 christos Exp $ */
/*-
* Copyright (c) 1999 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: compat_ldexp_ieee754.c,v 1.5 2010/04/23 19:04:54 drochner Exp $");
+__RCSID("$NetBSD: compat_ldexp_ieee754.c,v 1.6 2016/08/27 09:11:56 christos Exp $");
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
@@ -40,6 +40,7 @@ __RCSID("$NetBSD: compat_ldexp_ieee754.c
double ldexp(double, int);
+#include <stdio.h>
/*
* Multiply the given value by 2^expon.
*/
@@ -99,8 +100,19 @@ ldexp(double val, int expon)
* Calculate the new exponent and check for underflow and overflow.
*/
newexp = oldexp + expon;
+ printf("ee %#x oldexp %#x\n", oldexp, expon);
- if (newexp <= 0) {
+ if (newexp >= DBL_EXP_INFNAN ||
+ (oldexp >= 0 && expon >= DBL_EXP_INFNAN)) {
+ /*
+ * The result overflowed; return +/-Inf.
+ */
+ u.dblu_dbl.dbl_exp = DBL_EXP_INFNAN;
+ u.dblu_dbl.dbl_frach = 0;
+ u.dblu_dbl.dbl_fracl = 0;
+ errno = ERANGE;
+ return (u.dblu_d);
+ } else if (newexp <= 0) {
/*
* The output number is either denormal or underflows (see
* comments in machine/ieee.h).
@@ -123,15 +135,6 @@ ldexp(double val, int expon)
mul.dblu_dbl.dbl_exp = expon + DBL_EXP_BIAS;
u.dblu_d *= mul.dblu_d;
return (u.dblu_d);
- } else if (newexp >= DBL_EXP_INFNAN) {
- /*
- * The result overflowed; return +/-Inf.
- */
- u.dblu_dbl.dbl_exp = DBL_EXP_INFNAN;
- u.dblu_dbl.dbl_frach = 0;
- u.dblu_dbl.dbl_fracl = 0;
- errno = ERANGE;
- return (u.dblu_d);
} else {
/*
* The result is normal; just replace the old exponent with the
