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Re: [PATCH] Account for prologue spills in reg_pressure scheduling
- From: Sebastian Pop <sebpop at gmail dot com>
- To: Maxim Kuvyrkov <maxim dot kuvyrkov at linaro dot org>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, Vladimir Makarov <vmakarov at redhat dot com>, Richard Sandiford <rdsandiford at googlemail dot com>
- Date: Mon, 20 Oct 2014 20:44:17 +0000
- Subject: Re: [PATCH] Account for prologue spills in reg_pressure scheduling
- Authentication-results: sourceware.org; auth=none
- References: <FE7CEF4D-A27B-46D0-96B3-3569C1558DF9 at linaro dot org> <20141020191105 dot GB30024 at f1 dot c dot bardezibar dot internal> <ED2138EC-B4EA-4BBA-AC29-5B5A3B628A9F at linaro dot org>
Maxim Kuvyrkov wrote:
> Thanks, benchmarking results are welcome! AArch64 doesn't use reg_pressure
> scheduling by default. Use "-fsched-pressure
> --param=sched-pressure-algorithm=2" to enable same thing as on ARM. I would
> imagine C++ and Fortran floating-point code to be most affected.
On aarch64 I only see perf improvements with your patch: no perf degradations on
all the tests that I have run.
base0: r216447, -O3
base1: r216447, -O3 -fsched-pressure --param=sched-pressure-algorithm=2
patch: r216447 + your patch, -O3 -fsched-pressure --param=sched-pressure-algorithm=2
patch vs. base1 is only an improvement.
base1 vs. base0 has a few good improvements, and some small degradations: your
patch improves the perf for one of the degradations to the point it is better
now with -fsched-pressure --param=sched-pressure-algorithm=2 than at -O3.
Could we turn on "-fsched-pressure --param=sched-pressure-algorithm=2" by
default for aarch64?