[Bug c++/82505] g++ -O3 -funroll-loops generates weird code

2017-10-10 Thread redi at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82505 --- Comment #6 from Jonathan Wakely --- Ah no, because we have global pointers here, with potentially unknowable aliasing, as Alexander said.

[Bug c++/82505] g++ -O3 -funroll-loops generates weird code

2017-10-10 Thread redi at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82505 --- Comment #5 from Jonathan Wakely --- dup of PR 82394?

[Bug c++/82505] g++ -O3 -funroll-loops generates weird code

2017-10-10 Thread amonakov at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82505 Alexander Monakov changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED CC|

[Bug c++/82505] g++ -O3 -funroll-loops generates weird code

2017-10-10 Thread barto at cambridgesemantics dot com
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82505 --- Comment #3 from David Barto --- I understand that it can't optimize much, my major concern is that the pointer version of the code is so much worse than the index version of the code.

[Bug c++/82505] g++ -O3 -funroll-loops generates weird code

2017-10-10 Thread glisse at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82505 --- Comment #2 from Marc Glisse --- dest/src might alias anything (even themselves), so the compiler can't really optimize much.

[Bug c++/82505] g++ -O3 -funroll-loops generates weird code

2017-10-10 Thread barto at cambridgesemantics dot com
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82505 --- Comment #1 from David Barto --- This is gcc-mp-7 pre-built object from MacPorts. Should have mentioned that.