------- Comment #19 from hjl dot tools at gmail dot com 2010-09-16 14:17 ------- (In reply to comment #17) > That's true. But many expanders can make use of DECL_ALIGN information, e.g. > to choose faster code. If cfgexpand keeps doing what it does now, namely > bumping DECL_ALIGN of variables up to PREFERRED_STACK_BOUNDARY even when in > the > end the stack block doesn't end up being aligned that way, then it lies to the > expander
The problem isn't limited to stack. > and that will hit us again and again. On x86-64/i686, I don't think we want > to > prevent memcpy folding as your patch does, at least not for CPUs where movu* > is > fast. That is true. Whatever we do, we can't lie about alignment, on stack or not. Once we fix that, the rest shouldn't be too hard to fix. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45678
