https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62631
--- Comment #32 from amker at gcc dot gnu.org --- (In reply to dave.anglin from comment #30) > On 2015-02-08, at 9:09 AM, amker at gcc dot gnu.org wrote: > > > Ah, candidate 5 is considered cheaper according to the cost table. > > Is this a problem with insn costs, or a problem in the estimation of the > total cost > for each candidate? The total cost I think. Cost in IVOPT is tricky and inaccurate since 1) it needs to estimate cost of RTL on gimple IR; 2) The rtx expression cost is computed together with address expression cost, which doesn't happen in other part of GCC. I can try to make the case less vulnerable for now. Should we consider this as a missed optimization since GCC never did the optimization for the case before (and still not for mentioned targets)? Thanks, bin > > Dave > -- > John David Anglin dave.ang...@bell.net
