On 11/19/18 2:30 PM, Pat Haugen wrote: >> This is a follow-up from >> https://gcc.gnu.org/ml/gcc-patches/2018-11/msg01525.html >> This version introduces an "artificial" property of the dependencies >> produced in >> sched-deps.c that is recorded when they are created due to >> MAX_PENDING_LIST_LENGTH >> and they are thus ignored in the model_analyze_insns ALAP calculation. >> >> This approach gives most of the benefits of the original patch [1] on >> aarch64. >> I tried it on the cactusADM hot function (bench_staggeredleapfrog2_) on >> powerpc64le-unknown-linux-gnu >> with -O3 and found that the initial version proposed did indeed increase the >> instruction count >> and stack space. This version gives a small improvement on powerpc in terms >> of instruction count >> (number of st* instructions stays the same), so I'm hoping this version >> addresses Pat's concerns. >> Pat, could you please try this version out if you've got the chance? >> > I tried the new verison on cactusADM, it's showing a 2% degradation. I've > kicked off a full CPU2006 run just to see if any others are affected.
The other benchmarks were neutral. So the only benchmark showing a change is the 2% degradation on cactusADM. Comparing the generated .s files for bench_staggeredleapfrog2_(), there is about a 0.7% increase in load insns and still the 1% increase in store insns. -Pat
