On Tue, Dec 5, 2017 at 4:00 AM, Martin Jambor <mjam...@suse.cz> wrote: > On Tue, Dec 05 2017, Martin Jambor wrote: >> On Tue, Dec 05 2017, Martin Jambor wrote: >> Hi, >> >>> Hi, >>> >>> this is a followup to Richi's >>> https://gcc.gnu.org/ml/gcc-patches/2017-11/msg02396.html to fix PR >>> 83141. The basic idea is simple, be just as conservative about type >>> changing MEM_REFs as we are about actual VCEs. >>> >>> I have checked how that would affect compilation of SPEC 2006 and (non >>> LTO) Mozilla Firefox and am happy to report that the difference was >>> tiny. However, I had to make the test less strict, otherwise testcase >>> gcc.dg/guality/pr54970.c kept failing because it contains folded memcpy >>> and expects us to track values accross: >>> >>> int a[] = { 1, 2, 3 }; >>> /* ... */ >>> __builtin_memcpy (&a, (int [3]) { 4, 5, 6 }, sizeof (a)); >>> /* { dg-final { gdb-test 31 "a\[0\]" "4" } } */ >>> /* { dg-final { gdb-test 31 "a\[1\]" "5" } } */ >>> /* { dg-final { gdb-test 31 "a\[2\]" "6" } } */ >>> >>> SRA is able to load replacement of a[0] directly from the temporary >>> array which is apparently necessary to generate proper debug info. I >>> have therefore allowed the current transformation to go forward if the >>> source does not contain any padding or if it is a read-only declaration. >> >> Ah, the read-only test is of course bogus, it was a last minute addition >> when I was apparently already too tired to think it through. Please >> disregard that line in the patch (it has passed bootstrap and testing >> without it). >> >> Sorry for the noise, >> >> Martin >> > > And for the record, below is the actual patch, after a fresh round of > re-testing to double check I did not mess up anything else. As before, > I'd like to ask for review, especially of the type_contains_padding_p > predicate and then would like to commit it to trunk. > > Thanks, > > Martin > > > 2017-12-05 Martin Jambor <mjam...@suse.cz> > > PR tree-optimization/83141 > * tree-sra.c (type_contains_padding_p): New function. > (contains_vce_or_bfcref_p): Move up in the file, also test for > MEM_REFs implicitely changing types with padding. Remove inline > keyword. > (build_accesses_from_assign): Check contains_vce_or_bfcref_p > before setting bit in should_scalarize_away_bitmap. >
This caused: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86763 H.J.
