[Bug c++/61121] -O2 -ftree-parallelize-loops=0 for maximum not accepted in 4.9.0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61121 --- Comment #10 from Paolo Carlini --- Jakub, is this a C++ front-end issue (if anything)?
[Bug c++/61121] -O2 -ftree-parallelize-loops=0 for maximum not accepted in 4.9.0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61121 Manuel López-Ibáñez changed: What|Removed |Added Target||x86_64-w64-mingw32 CC||manu at gcc dot gnu.org --- Comment #9 from Manuel López-Ibáñez --- "This option implies -pthread, and thus is only supported on targets that have support for -pthread." Does x86_64-w64-mingw32 support -pthread? You are better off asking in the mingw mailing lists. There are no Windows developers/users here.
[Bug c++/61121] -O2 -ftree-parallelize-loops=0 for maximum not accepted in 4.9.0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61121 --- Comment #8 from Jim Michaels jmichae3 at yahoo dot com --- in the mingw-w64 gcc compiler at least, -ftree-parallize-loops=12 -O2 runs single-threaded. https://gcc.gnu.org/ml/gcc-help/2007-01/msg00165.html I probably don't understand the compiler, but I have been trying with -static and without, using -Wall -Wextra -v -save-temps -ftree-parallelize-loops=12 -O2 -std=c++11 I have also tried 0 on that number with same results. I always get single-threaded programs, and my stuff contains a lot of vectors and loops. I have also tried with -floop-parallelize-all -ftree-slp-vectorize additionally with same results. it's like that -ftree-parallize-loops is being ignored by the compiler. I did what everybody said and used the posix/pthreads version. this has not helped. auto-threading seems broken in 4.9.0 v3rev2.
[Bug c++/61121] -O2 -ftree-parallelize-loops=0 for maximum not accepted in 4.9.0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61121 Jim Michaels jmichae3 at yahoo dot com changed: What|Removed |Added Summary|-ftree-parallelize-loops=n |-O2 |(n as value) not accepted |-ftree-parallelize-loops=0 |in 4.9.0|for maximum not accepted in ||4.9.0 --- Comment #6 from Jim Michaels jmichae3 at yahoo dot com --- changed title to something more appropriate since value is always numeric. so give 0 a special meaning. really, there is always a minimum of 1 thread. so the value 0 could be used for the max number of threads on the system or ther max number of threads on the system -1 (1 for the OS to use as a NICE factor).
[Bug c++/61121] -O2 -ftree-parallelize-loops=0 for maximum not accepted in 4.9.0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61121
--- Comment #7 from Jim Michaels jmichae3 at yahoo dot com ---
http://msdn.microsoft.com/en-us/library/windows/desktop/dd405485%28v=vs.85%29.aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/ms679351%28v=vs.85%29.aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/ms680582%28v=vs.85%29.aspx
in windows,
#if defined(_MSC_VER)||defined(__BORLANDC__)||defined(__MINGW32__)
#include windows.h
int64_t getmaxthreads(void) {
DWORD numprocs=GetActiveProcessorCount(ALL_PROCESSOR_GROUPS);
if (0==numprocs) {
//ERROR. do something.
DWORD lasterr=GetLastError();
//do something with error
return 0;//failure
}
return numprocs-1;
}
#endif
