public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug c++/54036] New: Negating a DFP NAN in C++ produces NAN not -NAN
@ 2012-07-19 20:46 bergner at gcc dot gnu.org
2012-07-24 21:08 ` [Bug libstdc++/54036] " bergner at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: bergner at gcc dot gnu.org @ 2012-07-19 20:46 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54036
Bug #: 54036
Summary: Negating a DFP NAN in C++ produces NAN not -NAN
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: bergner@gcc.gnu.org
ReportedBy: bergner@gcc.gnu.org
Target: powerpc*-linux, x86*-linux
When negating a DFP NaN, we produce another NaN and not a -NaN like we do when
using a C test case or with binary floating point (C or C++). This happens on
both my power64-linux and x86_64-linux systems.
bergner@bns:~> cat dfp-nan.C
#include <stdio.h>
#include <decimal/decimal>
using namespace std;
decimal::decimal64
my_nan (void)
{
decimal::decimal64 z = 0.0DD;
decimal::decimal64 v = z/z;
return v;
}
int
main (void)
{
decimal::decimal64 v;
v = my_nan ();
printf ("value is %Dg\n", v);
v = -v;
printf ("-value is %Dg\n", v);
return 0;
}
bergner@bns:~> g++ dfp-nan.C -ldfp
bergner@bns:~> ./a.out
value is nan
-value is nan
The problem seems to be due to the following lines in
libstdc++-v3/include/decimal/decimal.h:
#define _DEFINE_DECIMAL_UNARY_OP(_Op, _Tp) \
inline _Tp operator _Op(_Tp __rhs) \
{ \
_Tp __tmp; \
__tmp.__setval(0 _Op __rhs.__getval()); \
return __tmp; \
}
_DEFINE_DECIMAL_UNARY_OP(+, decimal32)
_DEFINE_DECIMAL_UNARY_OP(+, decimal64)
_DEFINE_DECIMAL_UNARY_OP(+, decimal128)
_DEFINE_DECIMAL_UNARY_OP(-, decimal32)
_DEFINE_DECIMAL_UNARY_OP(-, decimal64)
_DEFINE_DECIMAL_UNARY_OP(-, decimal128)
This causes us to compute a "0 - nan" rather than a "-nan" and "0 - nan" will
not produce a -nan. The following change fixes the problem for me:
- __tmp.__setval(0 _Op __rhs.__getval()); \
+ __tmp.__setval(_Op __rhs.__getval()); \
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug libstdc++/54036] Negating a DFP NAN in C++ produces NAN not -NAN
2012-07-19 20:46 [Bug c++/54036] New: Negating a DFP NAN in C++ produces NAN not -NAN bergner at gcc dot gnu.org
@ 2012-07-24 21:08 ` bergner at gcc dot gnu.org
2012-07-25 17:02 ` bergner at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: bergner at gcc dot gnu.org @ 2012-07-24 21:08 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54036
--- Comment #1 from Peter Bergner <bergner at gcc dot gnu.org> 2012-07-24 21:07:58 UTC ---
Author: bergner
Date: Tue Jul 24 21:07:53 2012
New Revision: 189824
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=189824
Log:
Backport prospective patch from mainline
libstdc++-v3/
PR libstdc++/54036
* include/decimal/decimal.h (_DEFINE_DECIMAL_UNARY_OP): Use _Op as
a unary operator.
gcc/testsuite/
PR libstdc++/54036
* g++.dg/dfp/pr54036-1.C: New test.
* g++.dg/dfp/pr54036-2.C: Likewise.
* g++.dg/dfp/pr54036-3.C: Likewise.
Added:
branches/ibm/gcc-4_7-branch/gcc/testsuite/g++.dg/dfp/pr54036-1.C
branches/ibm/gcc-4_7-branch/gcc/testsuite/g++.dg/dfp/pr54036-2.C
branches/ibm/gcc-4_7-branch/gcc/testsuite/g++.dg/dfp/pr54036-3.C
branches/ibm/gcc-4_7-branch/libstdc++-v3/ChangeLog.ibm
Modified:
branches/ibm/gcc-4_7-branch/gcc/testsuite/ChangeLog.ibm
branches/ibm/gcc-4_7-branch/libstdc++-v3/include/decimal/decimal.h
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug libstdc++/54036] Negating a DFP NAN in C++ produces NAN not -NAN
2012-07-19 20:46 [Bug c++/54036] New: Negating a DFP NAN in C++ produces NAN not -NAN bergner at gcc dot gnu.org
2012-07-24 21:08 ` [Bug libstdc++/54036] " bergner at gcc dot gnu.org
@ 2012-07-25 17:02 ` bergner at gcc dot gnu.org
2012-08-06 18:00 ` paolo at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: bergner at gcc dot gnu.org @ 2012-07-25 17:02 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54036
--- Comment #2 from Peter Bergner <bergner at gcc dot gnu.org> 2012-07-25 17:02:39 UTC ---
Author: bergner
Date: Wed Jul 25 17:02:27 2012
New Revision: 189857
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=189857
Log:
Backport prospective patch from mainline
libstdc++-v3/
PR libstdc++/54036
* include/decimal/decimal.h (_DEFINE_DECIMAL_UNARY_OP): Use _Op as
a unary operator.
gcc/testsuite/
PR libstdc++/54036
* g++.dg/dfp/pr54036-1.C: New test.
* g++.dg/dfp/pr54036-2.C: Likewise.
* g++.dg/dfp/pr54036-3.C: Likewise.
Added:
branches/ibm/gcc-4_6-branch/gcc/testsuite/g++.dg/dfp/pr54036-1.C
branches/ibm/gcc-4_6-branch/gcc/testsuite/g++.dg/dfp/pr54036-2.C
branches/ibm/gcc-4_6-branch/gcc/testsuite/g++.dg/dfp/pr54036-3.C
Modified:
branches/ibm/gcc-4_6-branch/gcc/testsuite/ChangeLog.ibm
branches/ibm/gcc-4_6-branch/libstdc++-v3/ChangeLog.ibm
branches/ibm/gcc-4_6-branch/libstdc++-v3/include/decimal/decimal.h
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug libstdc++/54036] Negating a DFP NAN in C++ produces NAN not -NAN
2012-07-19 20:46 [Bug c++/54036] New: Negating a DFP NAN in C++ produces NAN not -NAN bergner at gcc dot gnu.org
2012-07-24 21:08 ` [Bug libstdc++/54036] " bergner at gcc dot gnu.org
2012-07-25 17:02 ` bergner at gcc dot gnu.org
@ 2012-08-06 18:00 ` paolo at gcc dot gnu.org
2012-08-06 18:07 ` paolo.carlini at oracle dot com
2012-08-06 18:07 ` paolo at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: paolo at gcc dot gnu.org @ 2012-08-06 18:00 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54036
--- Comment #3 from paolo at gcc dot gnu.org <paolo at gcc dot gnu.org> 2012-08-06 18:00:11 UTC ---
Author: paolo
Date: Mon Aug 6 18:00:00 2012
New Revision: 190185
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=190185
Log:
2012-08-06 Peter Bergner <bergner@vnet.ibm.com>
PR libstdc++/54036
* include/decimal/decimal.h (_DEFINE_DECIMAL_UNARY_OP): Use _Op as
a unary operator.
* testsuite/decimal/pr54036-1.cc: New test.
* testsuite/decimal/pr54036-2.cc: Likewise.
* testsuite/decimal/pr54036-3.cc: Likewise.
Added:
branches/gcc-4_7-branch/libstdc++-v3/testsuite/decimal/pr54036-1.cc
branches/gcc-4_7-branch/libstdc++-v3/testsuite/decimal/pr54036-2.cc
branches/gcc-4_7-branch/libstdc++-v3/testsuite/decimal/pr54036-3.cc
Modified:
branches/gcc-4_7-branch/libstdc++-v3/ChangeLog
branches/gcc-4_7-branch/libstdc++-v3/include/decimal/decimal.h
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug libstdc++/54036] Negating a DFP NAN in C++ produces NAN not -NAN
2012-07-19 20:46 [Bug c++/54036] New: Negating a DFP NAN in C++ produces NAN not -NAN bergner at gcc dot gnu.org
` (2 preceding siblings ...)
2012-08-06 18:00 ` paolo at gcc dot gnu.org
@ 2012-08-06 18:07 ` paolo.carlini at oracle dot com
2012-08-06 18:07 ` paolo at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: paolo.carlini at oracle dot com @ 2012-08-06 18:07 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54036
Paolo Carlini <paolo.carlini at oracle dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |FIXED
Target Milestone|--- |4.7.2
--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-08-06 18:07:35 UTC ---
Fixed mainline and 4.7.2.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug libstdc++/54036] Negating a DFP NAN in C++ produces NAN not -NAN
2012-07-19 20:46 [Bug c++/54036] New: Negating a DFP NAN in C++ produces NAN not -NAN bergner at gcc dot gnu.org
` (3 preceding siblings ...)
2012-08-06 18:07 ` paolo.carlini at oracle dot com
@ 2012-08-06 18:07 ` paolo at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: paolo at gcc dot gnu.org @ 2012-08-06 18:07 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54036
--- Comment #4 from paolo at gcc dot gnu.org <paolo at gcc dot gnu.org> 2012-08-06 18:06:46 UTC ---
Author: paolo
Date: Mon Aug 6 18:06:42 2012
New Revision: 190186
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=190186
Log:
2012-08-06 Paolo Carlini <paolo.carlini@oracle.com>
* testsuite/decimal/mixed-mode-cmp_neg.cc: Add test variable; minor
tweaks.
* testsuite/decimal/unary-arith.cc: Likewise.
* testsuite/decimal/ctor.cc: Likewise.
* testsuite/decimal/conversion-to-integral.cc: Likewise.
* testsuite/decimal/make-decimal.cc: Likewise.
* testsuite/decimal/comparison.cc: Likewise.
* testsuite/decimal/incdec-memfunc.cc: Likewise.
* testsuite/decimal/conversion-to-generic-float.cc: Likewise.
* testsuite/decimal/compound-assignment-memfunc.cc: Likewise.
* testsuite/decimal/cast_neg.cc: Likewise.
* testsuite/decimal/incdec.cc: Likewise.
* testsuite/decimal/mixed-mode-arith_neg.cc: Likewise.
* testsuite/decimal/binary-arith.cc: Likewise.
* testsuite/decimal/conversion-from-float.cc: Likewise.
* testsuite/decimal/conversion-from-integral.cc: Likewise.
* testsuite/decimal/compound-assignment.cc: Likewise.
2012-08-06 Peter Bergner <bergner@vnet.ibm.com>
PR libstdc++/54036
* include/decimal/decimal.h (_DEFINE_DECIMAL_UNARY_OP): Use _Op as
a unary operator.
* testsuite/decimal/pr54036-1.cc: New test.
* testsuite/decimal/pr54036-2.cc: Likewise.
* testsuite/decimal/pr54036-3.cc: Likewise.
Added:
trunk/libstdc++-v3/testsuite/decimal/pr54036-1.cc
trunk/libstdc++-v3/testsuite/decimal/pr54036-2.cc
trunk/libstdc++-v3/testsuite/decimal/pr54036-3.cc
Modified:
trunk/libstdc++-v3/ChangeLog
trunk/libstdc++-v3/include/decimal/decimal.h
trunk/libstdc++-v3/testsuite/decimal/binary-arith.cc
trunk/libstdc++-v3/testsuite/decimal/cast_neg.cc
trunk/libstdc++-v3/testsuite/decimal/comparison.cc
trunk/libstdc++-v3/testsuite/decimal/compound-assignment-memfunc.cc
trunk/libstdc++-v3/testsuite/decimal/compound-assignment.cc
trunk/libstdc++-v3/testsuite/decimal/conversion-from-float.cc
trunk/libstdc++-v3/testsuite/decimal/conversion-from-integral.cc
trunk/libstdc++-v3/testsuite/decimal/conversion-to-generic-float.cc
trunk/libstdc++-v3/testsuite/decimal/conversion-to-integral.cc
trunk/libstdc++-v3/testsuite/decimal/ctor.cc
trunk/libstdc++-v3/testsuite/decimal/incdec-memfunc.cc
trunk/libstdc++-v3/testsuite/decimal/incdec.cc
trunk/libstdc++-v3/testsuite/decimal/make-decimal.cc
trunk/libstdc++-v3/testsuite/decimal/mixed-mode-arith_neg.cc
trunk/libstdc++-v3/testsuite/decimal/mixed-mode-cmp_neg.cc
trunk/libstdc++-v3/testsuite/decimal/unary-arith.cc
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-08-06 18:07 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-07-19 20:46 [Bug c++/54036] New: Negating a DFP NAN in C++ produces NAN not -NAN bergner at gcc dot gnu.org
2012-07-24 21:08 ` [Bug libstdc++/54036] " bergner at gcc dot gnu.org
2012-07-25 17:02 ` bergner at gcc dot gnu.org
2012-08-06 18:00 ` paolo at gcc dot gnu.org
2012-08-06 18:07 ` paolo.carlini at oracle dot com
2012-08-06 18:07 ` paolo at gcc dot gnu.org
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).