[ https://issues.apache.org/jira/browse/STDCXX-51?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12600120#action_12600120 ] 

Farid Zaripov commented on STDCXX-51:
-------------------------------------

On x86 platform copying of the floating-point value using fld + fstp assembly commands converting the snan value to qnan.

So the __rw_fmat_infinite() on compilers, that uses fld+fstp (i.e. MSVC), will always print qnan when snan value is passed, because of the parameter val passed by value.

> infinity, NaN formatted differently on different platforms
> ----------------------------------------------------------
>
>                 Key: STDCXX-51
>                 URL: https://issues.apache.org/jira/browse/STDCXX-51
>             Project: C++ Standard Library
>          Issue Type: Improvement
>          Components: 22. Localization
>    Affects Versions: 4.1.2, 4.1.3, 4.1.4, 4.2.0, 4.2.1
>         Environment: all
>            Reporter: Martin Sebor
>            Assignee: Martin Sebor
>            Priority: Minor
>             Fix For: 4.2.2
>
>         Attachments: num_put.diff
>
>   Original Estimate: 13h
>          Time Spent: 13h
>  Remaining Estimate: 8h
>
> The output of the program below is different depending on the operating system it runs on. It should be the same (preferably like that on AIX).
> {noformat}
> $ cat u.cpp && uname -sr && make u -r && ./u
> #include <iostream>
> #include <limits>
> int main ()
> {
>     std::cout << std::numeric_limits<double>::infinity () << '\n'
>               << std::numeric_limits<double>::quiet_NaN () << '\n'
>               << std::numeric_limits<double>::signaling_NaN () << '\n'; 
> }
> SunOS 5.9
> gcc -c -I/build/sebor/dev/stdlib/include/ansi -D_RWSTDDEBUG   -pthreads -D_RWSTD_USE_CONFIG -I/build/sebor/gcc-3.4.3-15s/include -I/build/sebor/dev/stdlib/include -I/build/sebor/dev/stdlib/examples/include  -pedantic -nostdinc++ -g  -Wall -W -Wcast-qual -Winline -Wshadow -Wwrite-strings -Wno-long-long  u.cpp
> gcc u.o -o u -pthreads -L/build/sebor/gcc-3.4.3-15s/lib -lstd15s  -lsupc++ -lm
> rm u.o
> inf
> nan
> nan
> $ uname -vs && gmake u -r && ./u
> AIX 5
> xlCcore_r -c -I/build/sebor/dev/stdlib/include/ansi -D_RWSTDDEBUG    -D_RWSTD_USE_CONFIG -I/build/sebor/vacpp-7.0.0.3-15D/include -I/build/sebor/dev/stdlib/include -I/build/sebor/dev/stdlib/examples/include  -g  -q64  -qtemplateregistry=u.ti   u.cpp
> xlCcore_r u.o -o u -I/build/sebor/dev/stdlib/include/ansi -D_RWSTDDEBUG    -D_RWSTD_USE_CONFIG -liconv -brtl   -q64 -I/build/sebor/dev/stdlib/include/ansi -D_RWSTDDEBUG    -D_RWSTD_USE_CONFIG -I/build/sebor/vacpp-7.0.0.3-15D/include -I/build/sebor/dev/stdlib/include -I/build/sebor/dev/stdlib/examples/include  -qtemplateregistry=u.ti -L/build/sebor/vacpp-7.0.0.3-15D/lib -lstd15D   -lm
> rm u.o
> inf
> nanq
> nans
> {noformat}

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.