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authorAdhemerval Zanella <azanella@linux.vnet.ibm.com>2012-04-11 16:30:13 -0300
committerAndreas Jaeger <aj@suse.de>2012-04-17 22:12:53 +0200
commit76da7265320010c7a273ed99f53938c0f32d5fad (patch)
treef094871a5f38652d2d320a11423fee602a8746e6 /math/w_ilogb.c
parent0396e69dbefb3630651d93e0a7526c4326a071bb (diff)
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Fix ilogb exception and errno (bug 6794)
[BZ #6794] Following Joseph comments about bug 6794, here is a proposed fix. It turned out to be a large fix mainly because I had to move some file along to follow libm files/names conventions. Basically I have added wrappers (w_ilogb.c, w_ilogbf.c, w_ilogbl.c) that now calls the symbol '__ieee754_ilogb'. The wrappers checks for '__ieee754_ilogb' output and set the errno and raise exceptions as expected. The '__ieee754_ilogb' is implemented in sysdeps. I have moved the 's_ilogb[f|l]' files to e_ilogb[f|l] and renamed the '__ilogb[f|l]' to '__ieee754_ilogb[f|l]'. I also found out a bug in i386 and x86-64 assembly coded ilogb implementation where it raises a FE_DIVBYZERO when argument is '0.0'. I corrected this issue as well. Finally I added the errno and FE_INVALID tests for 0.0, NaN and +-InF argument. Tested on i386, x86-64, ppc32 and ppc64.
Diffstat (limited to 'math/w_ilogb.c')
-rw-r--r--math/w_ilogb.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/math/w_ilogb.c b/math/w_ilogb.c
new file mode 100644
index 0000000000..c87b517c50
--- /dev/null
+++ b/math/w_ilogb.c
@@ -0,0 +1,42 @@
+/* Copyright (C) 2012 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Adhemerval Zanella <azanella@linux.vnet.ibm.com>, 2011.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <math.h>
+#include <errno.h>
+#include <math_private.h>
+
+/* wrapper ilogb */
+int
+__ilogb (double x)
+{
+ int r = __ieee754_ilogb (x);
+ if (__builtin_expect (r == FP_ILOGB0, 0)
+ || __builtin_expect (r == FP_ILOGBNAN, 0)
+ || __builtin_expect (r == INT_MAX, 0))
+ {
+ __set_errno (EDOM);
+ feraiseexcept (FE_INVALID);
+ }
+ return r;
+}
+
+weak_alias (__ilogb, ilogb)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__ilogb, __ilogbl)
+weak_alias (__ilogb, ilogbl)
+#endif