Hi Ira, thanks for your answer, however:
On 31 May 2011 08:06, Ira Rosen <i...@il.ibm.com> wrote: >> This test fails for me because I get 4 vectorized loops instead of 3. >> There are multiple other tests that generate more vectorization then >> expected. I'd like to understand the reason for these failures, but I >> can't see what motivates the choice of only 3 vectorized loops among >> the 4 vectorizable loops of the test. Can someone enlighten me? > > The fourth loop (line 104) has only 3 scalar iterations, too few to > vectorize unless your target has vectors of 2 shorts. My port has vectors of 2 shorts, but I don't expose them directly to GCC. The V2HI type is defined, but UNITS_PER_SIMD_WORD always returns 8, which I believe should prompt GCC to use V4HI which is also defined. Regarding slp-3.c I don't get why the loop you point isn't vectorizable. I my version of the file (4.5 branch), I see 9 short copies in a loop iterating 4 times (a total of 36 short assignements). After the vectorization pass, I get 9 V4HI assignments which seem totally right. I don't see why this shouldn't be the case... Many thanks, Fred
