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Ilya Tocar 983dcf70ba cmd/compile/internal/ssa: update regalloc in loops
Currently we don't lift spill out of loop if loop contains call.
However often we have code like this:

for .. {
    if hard_case {
	call()
    }
    // simple case, without call
}

So instead of checking for any call, check for unavoidable call.
For #22698 cases I see:
mime/quotedprintable/Writer-6                   10.9µs ± 4%      9.2µs ± 3%   -15.02%  (p=0.000 n=8+8)
And:
compress/flate/Encode/Twain/Huffman/1e4-6       99.4µs ± 6%     90.9µs ± 0%    -8.57%  (p=0.000 n=8+8)
compress/flate/Encode/Twain/Huffman/1e5-6       760µs ± 1%      725µs ± 1%     -4.56%  (p=0.000 n=8+8)
compress/flate/Encode/Twain/Huffman/1e6-6       7.55ms ± 0%      7.24ms ± 0%     -4.07%  (p=0.000 n=8+7)

There are no significant changes on go1 benchmarks.
But for cases with runtime arch checks, where we call generic version on old hardware,
there are respectable performance gains:
math/RoundToEven-6                             1.43ns ± 0%     1.25ns ± 0%   -12.59%  (p=0.001 n=7+7)
math/bits/OnesCount64-6                        1.60ns ± 1%     1.42ns ± 1%   -11.32%  (p=0.000 n=8+8)

Also on some runtime benchmarks loops have less loads and higher performance:
runtime/RuneIterate/range1/ASCII-6             15.6ns ± 1%     13.9ns ± 1%   -10.74%  (p=0.000 n=7+8)
runtime/ArrayEqual-6                           3.22ns ± 0%     2.86ns ± 2%   -11.06%  (p=0.000 n=7+8)

Fixes #22698
Updates #22234

Change-Id: I0ae2f19787d07a9026f064366dedbe601bf7257a
Reviewed-on: https://go-review.googlesource.com/84055
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2018-03-20 21:02:39 +00:00
.github github: update Pull Request template 2018-02-21 02:07:46 +00:00
api syscall: support Getwd on all BSDs 2018-02-13 15:41:19 +00:00
doc Revert "doc: remove non-prime from list of primes in spec" 2018-03-19 21:51:23 +00:00
lib/time all: use HTTPS for iana.org links 2018-02-13 18:36:48 +00:00
misc runtime: identify special functions by flag instead of address 2018-03-15 17:31:57 +00:00
src cmd/compile/internal/ssa: update regalloc in loops 2018-03-20 21:02:39 +00:00
test test/codegen: port comparisons tests to codegen 2018-03-20 19:38:06 +00:00
.gitattributes
.gitignore .gitignore: ignore src/cmd/dist/dist 2017-10-28 21:55:49 +00:00
AUTHORS A+C: update my name and spelling 2018-02-21 04:12:57 +00:00
CONTRIBUTING.md all: restore changes from faulty merge/revert 2018-02-12 20:13:59 +00:00
CONTRIBUTORS C: add Filippo Valsorda's @golang.org email 2018-03-12 22:29:04 +00:00
LICENSE
PATENTS
README.md all: restore changes from faulty merge/revert 2018-02-12 20:13:59 +00:00
favicon.ico website: recreate 16px and 32px favicon 2016-08-25 15:43:32 +00:00
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