2016-06-21 23:57 GMT+03:00 Jeff Law <l...@redhat.com>: > On 06/16/2016 05:06 AM, Ilya Enkovich wrote: >> >> Hi, >> >> This patch fixes incorrect comparison vectorization for booleans. >> The problem is that regular comparison which works for scalars >> doesn't work for vectors due to different binary representation. >> Also this never works for scalar masks. >> >> This patch replaces such comparisons with bitwise operations >> which work correctly for both vector and scalar masks. >> >> Bootstrapped and regtested on x86_64-unknown-linux-gnu. Is it >> OK for trunk? What should be done for gcc-6-branch? Port this >> patch or just restrict vectorization for comparison of booleans? >> >> Thanks, >> Ilya >> -- >> gcc/ >> >> 2016-06-15 Ilya Enkovich <ilya.enkov...@intel.com> >> >> PR middle-end/71488 >> * tree-vect-patterns.c (vect_recog_mask_conversion_pattern): >> Support >> comparison of boolean vectors. >> * tree-vect-stmts.c (vectorizable_comparison): Vectorize >> comparison >> of boolean vectors using bitwise operations. >> >> gcc/testsuite/ >> >> 2016-06-15 Ilya Enkovich <ilya.enkov...@intel.com> >> >> PR middle-end/71488 >> * g++.dg/pr71488.C: New test. >> * gcc.dg/vect/vect-bool-cmp.c: New test. > > OK. Given this is a code generation bug, I'll support porting this patch to > the gcc-6 branch. Is there any reason to think that porting out be more > risky than usual? It looks pretty simple to me, am I missing some subtle > dependency?
I don't feel this patch is too risky. I asked only because simple restriction on masks comparison is even more safe. Thanks, Ilya > > jeff >
