On Fri, May 31, 2024 at 10:05:55PM -0600, Jeff Law wrote: > > > On 5/31/24 9:03 AM, Robin Dapp wrote: > > Hi, > > > > before noce_find_if_block processes a block it sets up an if_info > > structure that holds the original costs. At that point the costs of > > the then/else blocks have not been added so we only care about the > > "if" cost. > > > > The code originally used BRANCH_COST for that but was then changed > > to COST_N_INSNS (2) - a compare and a jump. > > This patch computes the jump costs via > > insn_cost (if_info.jump, ...) > > which is supposed to incorporate the branch costs and, in case of a CC > > comparison, > > pattern_cost (if_info.cond, ...) > > which is supposed to account for the CC creation. > > > > For compare_and_jump patterns insn_cost should have already computed > > the right cost. > > > > Does this "split" make sense, generally? > > > > Bootstrapped and regtested on x86, aarch64 and power10. Regtested > > on riscv. > > > > Regards > > Robin > > > > gcc/ChangeLog: > > > > * ifcvt.cc (noce_process_if_block): Subtract condition pattern > > cost if applicable. > > (noce_find_if_block): Use insn_cost and pattern_cost for > > original cost. > OK. Obviously we'll need to be on the lookout for regressions. My bet is > on s390 since you already tested the x86, aarch64 & p10 targets :-)
I just gave it a try on s390 where bootstrap and regtest were successful. Cheers, Stefan > > > jeff >
