On Tue, Aug 19, 2014 at 10:39 PM, Steve Ellcey <sell...@mips.com> wrote: > Here is an official submission for the switch optimization described in > PR 54742. I have addressed the formatting/comment issues that were raised > and also added a test case based on comment #27 from PR 54742 and I fixed a > bug I found while doing benchmarking with SPEC2006 (the perl benchmark was > generating an ICE in a routine with multiple switch statements). > > I ran the benchmarking to see if I could find any more tests that are > helped like coremark is and while I found a number of benchmarks in > SPEC 2006 and EEMBC where the optimization is triggered, this optimization > generally didn't affect the performance of those benchmarks. The biggest > impact I could find was on the perl benchmark in SPEC where I saw around > a 0.4% improvement on a MIPS 74k. Not huge, but not nothing. > > So, OK to checkin?
Without looking at the patch in detail what is the rationale for the pass placement (looks quite early)? I would have guessed that the pass could benefit from value-range analysis. Jeff, Steve is it possible to trigger the transform by simply "manually forcing" the right "path" jump-threads from inside VRP? That is, basically integrate the transform part with the existing jump threading framework but do an alternate discovery pass? Thanks, Richard. > Steve Ellcey > sell...@mips.com > > > 2014-08-12 Steve Ellcey <sell...@mips.com> > > PR tree-opt/54742 > * Makefile.in (OBJS): Add tree-switch-shortcut.o. > * common.opt (ftree-switch-shortcut): New. > * opts.c (default_options_table): Add OPT_ftree_switch_shortcut. > * params.def (PARAM_MAX_SWITCH_INSNS): New. > (PARAM_MAX_SWITCH_PATHS): New. > * passes.def (pass_tree_switch_shortcut): New. > * timevar.def (TV_TREE_SWITCH_SHORTCUT): New. > * tree-pass.h (make_pass_tree_switch_shortcut): New. > * tree-switch-shortcut.c: New. > > > 2014-08-12 Steve Ellcey <sell...@mips.com> > > PR tree-opt/54742 > * gcc.dg/pr54742.c: New test. >
