[PATCH] D30254: Remove sometimes faulty rewrite of memcpy in instcombine.

[Mikael Holmén via Phabricator via llvm-commits]

uabelho added a comment.

Ok, with help from llvm-dev I now get more stable benchmark numbers.
I don't if this is still too messy to draw any conclusions from, but
at least it's significantly more stable than before.

I've run the benchmarks with

lnt runtest nt --sandbox SANDBOX --cflag=-m32 --cc <path-to-compiler> --test-suite <path-to-test-suite> --threads 1 --build-threads 12 --benchmarking-only --use-perf=1 --make-param="RUNUNDER=taskset -c 1" --benchmarking-only --multisample=3

lnt runtest nt doesn't have any "--cxxflags" flag so I'm only using
--cflag=-m32.

(The failing tests I got with -m32 seems to be connected with zconf.h,
maybe https://bugs.launchpad.net/ubuntu/+source/zlib/+bug/1155307
I tried the workaround suggested at the end but it failed in some
unclear way then so I simply hope that those three tests aren't vital for
the results we're looking for.)

Base vs base comparison (only improvements):
http://i.imgur.com/6eTlc7H.png

Patch vs base comparison (also only improvements):
http://i.imgur.com/ye8EDSl.png

Ok?


https://reviews.llvm.org/D30254