Compilation fails of the small code sample found at:
http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt12ch31s03.html
I am using the suggested compiler options.
This is the code (cut and pasted from your documentation):
#include <vector>
#include <parallel/algorithm>
int main()
{
std::vector<int> v(100);
// ...
// Explicitly force a call to parallel sort.
__gnu_parallel::sort(v.begin(), v.end());
return 0;
}
If it is this code that is incorrect the docs should be fixed as there are not
many examples of parallel libstdc++ usage to be found on the net at the
moment.
This is g++ output:
g++ -v -save-temps -fopenmp -march=i686 -o test parallelsort.cpp
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.3.2-1ubuntu11'
--with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3
--program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug
--enable-objc-gc --enable-mpfr --enable-targets=all --enable-checking=release
--build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu
Thread model: posix
gcc version 4.3.2 (Ubuntu 4.3.2-1ubuntu11)
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-fopenmp' '-march=i686' '-o' 'test'
'-shared-libgcc' '-pthread'
/usr/lib/gcc/i486-linux-gnu/4.3.2/cc1plus -E -quiet -v -D_GNU_SOURCE
-D_REENTRANT parallelsort.cpp -D_FORTIFY_SOURCE=2 -march=i686 -fopenmp
-fpch-preprocess -o parallelsort.ii
ignoring nonexistent directory "/usr/local/include/i486-linux-gnu"
ignoring nonexistent directory
"/usr/lib/gcc/i486-linux-gnu/4.3.2/../../../../i486-linux-gnu/include"
ignoring nonexistent directory "/usr/include/i486-linux-gnu"
#include "..." search starts here:
#include <...> search starts here:
/usr/include/c++/4.3
/usr/include/c++/4.3/i486-linux-gnu
/usr/include/c++/4.3/backward
/usr/local/include
/usr/lib/gcc/i486-linux-gnu/4.3.2/include
/usr/lib/gcc/i486-linux-gnu/4.3.2/include-fixed
/usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-fopenmp' '-march=i686' '-o' 'test'
'-shared-libgcc' '-pthread'
/usr/lib/gcc/i486-linux-gnu/4.3.2/cc1plus -fpreprocessed parallelsort.ii
-quiet -dumpbase parallelsort.cpp -march=i686 -auxbase parallelsort -version
-fopenmp -fstack-protector -o parallelsort.s
GNU C++ (Ubuntu 4.3.2-1ubuntu11) version 4.3.2 (i486-linux-gnu)
compiled by GNU C version 4.3.2, GMP version 4.2.2, MPFR version 2.3.2.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: dc8f858cacda993dd8f70837f0d9565d
/usr/include/c++/4.3/parallel/algo.h: In function void
std::__parallel::sort(_RAIter, _RAIter) [with _RAIter =
__gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> > >]:
parallelsort.cpp:11: instantiated from here
/usr/include/c++/4.3/parallel/algo.h:1736: error: call of overloaded
sort(__gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> >
>&, __gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> >
>&, std::less<int>) is ambiguous
/usr/include/c++/4.3/parallel/algo.h:1741: note: candidates are: void
std::__parallel::sort(_RAIter, _RAIter, _Compare) [with _RAIter =
__gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> > >,
_Compare = std::less<int>]
/usr/include/c++/4.3/bits/stl_algo.h:4806: note: void
std::sort(_RAIter, _RAIter, _Compare) [with _RAIter =
__gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> > >,
_Compare = std::less<int>]
So it can't resolve the ambiguous overloading between a parallel and
non-parallel version of sort.
I am not sure which -march option i should be using, but i tried using none,
-march=i686, and -march=native, with identical results.
This is an up-to-date ubuntu 8.10, by the way.
--
Summary: Parallel mode example code does not compile
Product: gcc
Version: 4.3.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: j dot s dot sebastian at gmail dot com
GCC build triplet: i486-linux-gnu
GCC host triplet: i486-linux-gnu
GCC target triplet: i486-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38897
