| Message ID | BANLkTimUp8Rk3DFCHmqUikr=GSoG2y9jww@mail.gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
Index: tree-vect-data-refs.c =================================================================== --- tree-vect-data-refs.c (revision 174964) +++ tree-vect-data-refs.c (working copy) @@ -1248,7 +1248,9 @@ vect_peeling_hash_get_most_frequent (void **slot, vect_peel_info elem = (vect_peel_info) *slot; vect_peel_extended_info max = (vect_peel_extended_info) data; - if (elem->count > max->peel_info.count) + if (elem->count > max->peel_info.count + || (elem->count == max->peel_info.count + && max->peel_info.npeel > elem->npeel)) { max->peel_info.npeel = elem->npeel; max->peel_info.count = elem->count;
Hi, gcc.dg/vect/vect-72.c is not expected to use loop peeling for alignment, but it does on ARM with double-word vectors. The loop contains two data-refs of type char: one is aligned and the other is misaligned by 1. When the cost model is disabled the peeling heuristic chooses to peel a number of scalar iterations that aligns the highest number of data-refs in the loop. When there are two (with different alignment), the decision is arbitrary, which causes the vectorizer to peel 7 iterations in vect-72.c, while not peeling at all is an obviously better option (at least since the cost model is disabled). This patch takes into account the required number of iterations to peel. Bootstrapped and tested on powerpc64-suse-linux, and tested the vectorizer testsuite on arm-linux-gnueabi. Committed. Ira ChangeLog: * tree-vect-data-refs.c (vect_peeling_hash_get_most_frequent): Take number of iterations to peel into account for equally frequent misalignment values.