Hi, On Sat, Apr 01, 2017 at 02:20:27PM +0200, Jakub Jelinek wrote: > As discussed in the PR, in the following testcase we don't if-convert > with the generic (and many other) tuning, because we default to > --param max-rtl-if-conversion-insns=1 in most of the tunings. > The problem we have is with multiple cmov instructions, but in the > testcase there is just one cmov and the other insn is turned into a SSE > max insn, which is fine. > > This patch stops artificially lowering that param, and for one_if_conv_insn > tuning it instead rejects the if-conversion if the resulting sequence has > multiple cmov instructions. The hook is passed if_info too, so it can > in the future do better heuristics based on predictability of the edges, > how far the uses of the cmov result are (I assume cmov major problem is > latency, right?) etc. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Does this change anything for targets that do not implement the new hook? It isn't immediately obvious from the patch. Segher
