on 2021/5/24 下午3:21, Kewen.Lin via Gcc-patches wrote: > Hi Andre, > > on 2021/5/24 下午2:17, Andre Vieira (lists) via Gcc-patches wrote: >> Hi, >> >> When vectorizing with --param vect-partial-vector-usage=1 the vectorizer >> uses an unpredicated (all-true predicate for SVE) main loop and a predicated >> tail loop. The way this was implemented seems to mean it re-uses the same >> vector-mode for both loops, which means the tail loop isn't an actual loop >> but only executes one iteration. >> >> This patch uses the knowledge of the conditions to enter an epilogue loop to >> help come up with a potentially more restricive upper bound. >> >> Regression tested on aarch64-linux-gnu and also ran the testsuite using >> '--param vect-partial-vector-usage=1' detecting no ICEs and no execution >> failures. >> >> Would be good to have this tested for PPC too as I believe they are the main >> users of the --param vect-partial-vector-usage=1 option. Can someone help me >> test (and maybe even benchmark?) this on a PPC target? >> > > > Thanks for doing this! I can test it on Power10 which enables this parameter > by default, also evaluate its impact on SPEC2017 Ofast/unroll. >
Bootstrapped/regtested on powerpc64le-linux-gnu Power10. SPEC2017 run didn't show any remarkable improvement/degradation. BR, Kewen
