On Dec 12, 2007, at 2:02 PM, Bill Wendling wrote: > On Dec 12, 2007 11:32 AM, Evan Cheng <[EMAIL PROTECTED]> wrote: >> On Dec 12, 2007, at 11:12 AM, Bill Wendling wrote: >>> I'm sure I could move it, but as Chris asked, isn't it trivial to >>> get >>> this information anyway? Also, I'm kind of hesitant to put so much >>> effort into compile-time performance issues when it doesn't even >>> have >>> partial (let alone full) functionality right now. We don't know what >>> impact any of those optimizations have or if they are necessary yet. >>> :-) >> >> It's something to keep in mind. Not critical right now if we are not >> hoisting anything with implicit defs / uses. >> > Sounds good. :-) > >> If we are keeping LICM before livevariables, we will have to compute >> liveness in the BB's where the invariants are hoisted to. Now that I >> think about it, we *cannot* use the register scavenger to do this >> because it also depends on kill / dead markers on the operands. The >> scavenger's job is not to add the kill / dead markers, it is to track >> what registers are live at any point of the BB. This means you'll >> have to walk the BB and track all physical register defs and uses in >> the BB. >> > I see. Okay, so by the time I get to the point where I'm moving > instructions that access physical registers, I should have the pass > after LiveVariables...
Yeah, maybe. :-) We'll discuss some more. Evan > > -bw > _______________________________________________ > llvm-commits mailing list > llvm-commits@cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
