tree d742b34e443272da728531f0498d266b68517b37
parent 2b29335120440273ce87e777e4d1d511fe7894b8
author Nigel Tao <nigeltao@golang.org> 1461892964 +1000
committer Nigel Tao <nigeltao@golang.org> 1461892964 +1000

Rearrange the emitCopy register allocation.

This minimizes the diff in a follow-up commit, when manually inlining.

It's not an optimization per se, but for the record:
name              old speed      new speed      delta
WordsEncode1e1-8   711MB/s ± 1%   700MB/s ± 1%  -1.64%   (p=0.000 n=9+10)
WordsEncode1e2-8   407MB/s ± 1%   430MB/s ± 0%  +5.57%  (p=0.000 n=10+10)
WordsEncode1e3-8   441MB/s ± 1%   447MB/s ± 0%  +1.52%    (p=0.000 n=8+8)
WordsEncode1e4-8   311MB/s ± 1%   322MB/s ± 0%  +3.69%   (p=0.000 n=9+10)
WordsEncode1e5-8   267MB/s ± 0%   267MB/s ± 1%    ~      (p=0.068 n=8+10)
WordsEncode1e6-8   312MB/s ± 1%   314MB/s ± 0%  +0.45%   (p=0.000 n=9+10)
RandomEncode-8    14.4GB/s ± 2%  14.4GB/s ± 2%    ~     (p=0.739 n=10+10)
_ZFlat0-8          792MB/s ± 1%   801MB/s ± 0%  +1.11%    (p=0.000 n=8+9)
_ZFlat1-8          435MB/s ± 1%   437MB/s ± 0%    ~      (p=0.857 n=9+10)
_ZFlat2-8         16.0GB/s ± 4%  16.3GB/s ± 1%    ~     (p=0.143 n=10+10)
_ZFlat3-8          613MB/s ± 0%   634MB/s ± 0%  +3.54%   (p=0.000 n=8+10)
_ZFlat4-8         7.96GB/s ± 1%  7.97GB/s ± 1%    ~      (p=0.829 n=8+10)
_ZFlat5-8          770MB/s ± 0%   773MB/s ± 0%  +0.33%    (p=0.000 n=8+9)
_ZFlat6-8          283MB/s ± 0%   283MB/s ± 0%  +0.13%    (p=0.043 n=8+9)
_ZFlat7-8          264MB/s ± 2%   265MB/s ± 0%  +0.61%    (p=0.000 n=9+9)
_ZFlat8-8          297MB/s ± 3%   299MB/s ± 0%    ~       (p=0.161 n=9+9)
_ZFlat9-8          247MB/s ± 1%   247MB/s ± 0%    ~       (p=0.465 n=8+9)
_ZFlat10-8        1.03GB/s ± 0%  1.05GB/s ± 1%  +1.75%    (p=0.000 n=9+9)
_ZFlat11-8         409MB/s ± 0%   412MB/s ± 0%  +0.64%    (p=0.000 n=8+8)