[Bug c++/60702] thread_local initialization

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60702 arturomdn at gmail dot com changed: What|Removed |Added CC||arturomdn at gmail dot com

[Bug tree-optimization/56309] -O3 optimizer generates conditional moves instead of compare and branch resulting in almost 2x slower code

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56309 --- Comment #16 from arturomdn at gmail dot com 2013-02-14 17:42:55 UTC --- With -ftree-vectorize -fno-tree-loop-if-convert flags it generated this for the loop in question: .L39: movq%rdi, %rdx addq(%rsi,%rax,8

[Bug tree-optimization/56309] -O3 optimizer generates conditional moves instead of compare and branch resulting in almost 2x slower code

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56309 --- Comment #14 from arturomdn at gmail dot com 2013-02-14 17:30:54 UTC --- I also did the experiment, with the same results... it got faster but not as fast as the version with conditional branch instead of conditional moves: ./by-ref

[Bug target/56309] -O3 optimizer generates conditional moves instead of compare and branch resulting in almost 2x slower code

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56309 --- Comment #10 from arturomdn at gmail dot com 2013-02-14 16:43:23 UTC --- Might be worth mentioning here what I said in the stackoverflow answer, that in this particular case the entire conditional branch can be avoided because it is

[Bug target/56309] -O3 optimizer generates conditional moves instead of compare and branch resulting in almost 2x slower code

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56309 --- Comment #9 from arturomdn at gmail dot com 2013-02-14 16:00:49 UTC --- I found in the Intel optimization guide an example of this idiom of comparing once and issuing two cmov back-to-back... so the problem isn't the two cmov,

[Bug target/56309] -O3 optimizer generates conditional moves instead of compare and branch resulting in almost 2x slower code

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56309 --- Comment #8 from arturomdn at gmail dot com 2013-02-14 15:53:15 UTC --- It is possible (just a guess) that the extra compare is causing an interlock in the processor since the first cmov is issued speculatively and the condition won'

[Bug target/56309] -O3 optimizer generates conditional moves instead of compare and branch resulting in almost 2x slower code

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56309 --- Comment #3 from arturomdn at gmail dot com 2013-02-13 20:29:12 UTC --- Intel Xeon X5570 @ 2.93GHz (In reply to comment #2) > Which target is this on? On some (most non x86 targets) conditional moves are > faster than compa

[Bug middle-end/56309] -O3 optimizer generates conditional moves instead of compare and branch resulting in almost 2x slower code

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56309 --- Comment #1 from arturomdn at gmail dot com 2013-02-13 20:22:51 UTC --- Created attachment 29443 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29443 Self contained source file with parameter x passed by reference (fast) T

[Bug middle-end/56309] New: -O3 optimizer generates conditional moves instead of compare and branch resulting in almost 2x slower code

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56309 Bug #: 56309 Summary: -O3 optimizer generates conditional moves instead of compare and branch resulting in almost 2x slower code Classification: Unclassified Product: gcc