On 11/8/18 6:10 AM, Kyrill Tkachov wrote: > The attached patch avoids that by making the alap calculation only > look at true dependencies. This shouldn't be too bad, since we use > INSN_PRIORITY as the final tie-breaker than that does take > anti-dependencies into account. > > This reduces the number of spills in the hot function from 436.cactusADM > by 14% on aarch64 at -O3 (and the number of instructions in general). > SPEC2017 shows a minor improvement on Cortex-A72 (about 0.1% overall). > Thanks to Wilco for the benchmarking.
I tried the patch on PowerPC since it also uses SCHED_PRESSURE_MODEL algorithm. For CPU2006 only cactusADM had a noticeable difference, but I'm seeing a 5% degradation. Looking at the generated asm for function bench_staggeredleapfrog2_(), I see about a 1% increase in number of loads and stores generated and an extra 100 bytes allocated on the stack. -Pat
