On Mon, Jul 3, 2017 at 5:12 PM, Jeff Law <l...@redhat.com> wrote: > On 04/18/2017 04:54 AM, Bin Cheng wrote: >> Hi, >> This is the same patch posted at >> https://gcc.gnu.org/ml/gcc-patches/2016-05/msg02000.html, >> after rebase against this patch series. This patch was blocked because >> without this patch >> series, it could generate worse code on targets with limited addressing mode >> support, like >> AArch64. >> There was some discussion about alternative fix for PRs, but after thinking >> twice I think >> this fix is in the correct direction. A CSE interface is useful to clean up >> code generated >> in vectorizer, and we should improve this CSE interface into a region base >> one. for the >> moment, optimal code is not generated on targets like x86, I believe it's >> because the CSE >> is weak and doesn't cover all basic blocks generated by vectorizer, the >> issue should be >> fixed if region-based CSE is implemented. >> Is it OK? >> >> Thanks, >> bin >> 2017-04-11 Bin Cheng <bin.ch...@arm.com> >> >> PR tree-optimization/68030 >> PR tree-optimization/69710 >> * tree-ssa-dom.c (cse_bbs): New function. >> * tree-ssa-dom.h (cse_bbs): New declaration. >> * tree-vect-data-refs.c (vect_create_addr_base_for_vector_ref): >> Re-associate address by splitting constant offset. >> (vect_create_data_ref_ptr, vect_setup_realignment): Record changed >> basic block. >> * tree-vect-loop-manip.c (vect_gen_prolog_loop_niters): Record >> changed basic block. >> * tree-vectorizer.c (tree-ssa-dom.h): Include header file. >> (changed_bbs): New variable. >> (vectorize_loops): Allocate and free CHANGED_BBS. Call cse_bbs. >> * tree-vectorizer.h (changed_bbs): New declaration. >> > So are you still interested in moving this forward Bin? I know you did > a minor update in response to Michael Meissner's problems. Is there > another update planned? Hi, Yes I want to move this forward, but better with confirmation whether the regression is real or just u-arch hazard. OTOH, given the proceeding 32 patches have been applied, I think there is no need to hold this one. It is proceeding patch rather than this one causes regression I guess.
> > THe only obvious thing I'd suggest changing in the DOM interface is to > have continue to walk the dominator tree, but do nothing for blocks that > are not in changed_bbs. That way you walk blocks in changed_bbs in > dominator order rather than in bb->index order. I will update patch as you suggested, but may take some time. Thanks, bin > > Jeff >
