Help w/ CFG/loop optimization problem?
Roger Sayle
roger@eyesopen.com
Tue Sep 10 15:53:00 GMT 2002
Hi Dale,
> Advice?
Spooky! I posted to patch to gcc-patches to fix a similar problem
(CFG vs LOOP) less than an hour after your question.
I think I know a possible fix. I believe that the "conditional branch
over an unconditional branch" idiom that GCC's initial RTL generation
uses is a historical artifact. I suspect that GCC now handles long
conditional branches perfectly well, so creating jumps over jumps
does nothing but confuse CFG, which in turn confuses LOOP.
Roger
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