On Thu, Aug 10, 2017 at 9:50 AM, Martin Liška <mli...@suse.cz> wrote: > On 08/02/2017 01:51 PM, Richard Biener wrote: >> On Wed, Aug 2, 2017 at 1:20 PM, Martin Liška <mli...@suse.cz> wrote: >>> Hello. >>> >>> After some discussions with Honza, I've decided to convert current code in >>> stmt.c that >>> is responsible for switch expansion. More precisely, I would like to >>> convert the code >>> to expand gswitch statements on tree level. Currently the newly created >>> pass is executed >>> at the end of tree optimizations. >>> >>> My plan for future is to inspire in [1] and come up with some more >>> sophisticated switch >>> expansions. For that I've been working on a paper where I'll summarize >>> statistics based >>> on what I've collected in openSUSE distribution with specially instrumented >>> GCC. If I'll be >>> happy I can also fit in to schedule of this year's Cauldron with a talk. >>> >>> Patch can bootstrap on ppc64le-redhat-linux and survives regression tests. >>> >>> Thoughts? >> >> First of all thanks. >> >> I think part of switch expansion moved to switch-conversion some time ago >> (emit_case_bit_tests). So maybe the full lowering should be in at least >> the same source file and it should maybe applied earlier for a subset of >> cases (very low number of cases for example). > > Hello. > > Agree! Eventually we should merge both files into a single one. I would > prefer to start > with new generic name of file (gimple-switch-low.c), which will eventually > eat content > of tree-switch-conversion.c. Is it acceptable approach?
Hmm, but the existing "lowering" part is called from the switch-conversion pass. So I'm not sure a new file is good. > As Jeff already accepted the patch, I will install it as soon as an agreement > in the question > will be done. > > Martin > >> >> Did you base the code on the RTL expansion code or did you re-write it from >> scratch? >> >> No further comments sofar. >> >> Richard. >> >>> Martin >>> >>> [1] https://www.nextmovesoftware.com/technology/SwitchOptimization.pdf >>> >>> gcc/ChangeLog: >>> >>> 2017-07-31 Martin Liska <mli...@suse.cz> >>> >>> * Makefile.in: Add gimple-switch-low.o. >>> * passes.def: Include pass_lower_switch. >>> * stmt.c (dump_case_nodes): Remove and move to >>> gimple-switch-low.c. >>> (case_values_threshold): Likewise. >>> (expand_switch_as_decision_tree_p): Likewise. >>> (emit_case_decision_tree): Likewise. >>> (expand_case): Likewise. >>> (balance_case_nodes): Likewise. >>> (node_has_low_bound): Likewise. >>> (node_has_high_bound): Likewise. >>> (node_is_bounded): Likewise. >>> (emit_case_nodes): Likewise. >>> * timevar.def: Add TV_TREE_SWITCH_LOWERING. >>> * tree-pass.h: Add make_pass_lower_switch. >>> * gimple-switch-low.c: New file. >>> >>> gcc/testsuite/ChangeLog: >>> >>> 2017-07-31 Martin Liska <mli...@suse.cz> >>> >>> * gcc.dg/tree-prof/update-loopch.c: Scan patterns in >>> switchlower. >>> * gcc.dg/tree-ssa/vrp104.c: Likewise. >>> --- >>> gcc/Makefile.in | 1 + >>> gcc/gimple-switch-low.c | 1226 >>> ++++++++++++++++++++++++ >>> gcc/passes.def | 1 + >>> gcc/stmt.c | 861 ----------------- >>> gcc/testsuite/gcc.dg/tree-prof/update-loopch.c | 10 +- >>> gcc/testsuite/gcc.dg/tree-ssa/vrp104.c | 2 +- >>> gcc/timevar.def | 1 + >>> gcc/tree-pass.h | 1 + >>> 8 files changed, 1236 insertions(+), 867 deletions(-) >>> create mode 100644 gcc/gimple-switch-low.c >>> >>> >
