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| author | Ilya Tocar <ilya.tocar@intel.com> | 2017-03-28 15:30:31 -0500 |
|---|---|---|
| committer | Ilya Tocar <ilya.tocar@intel.com> | 2017-04-07 15:40:25 +0000 |
| commit | e4a500ce1490a5db709da5880f0121e5eeac73cd (patch) | |
| tree | 99bc58f9a1d58b9f2824db56a55e575d857b6f66 /test/prove.go | |
| parent | d206af1e6c53df0c59d9466fe9c50415f9d8dcd5 (diff) | |
| download | go-e4a500ce1490a5db709da5880f0121e5eeac73cd.tar.gz go-e4a500ce1490a5db709da5880f0121e5eeac73cd.zip | |
cmd/compile/internal/gc: improve comparison with constant strings
Currently we expand comparison with small constant strings into len check
and a sequence of byte comparisons. Generate 16/32/64-bit comparisons,
instead of bytewise on 386 and amd64. Also increase limits on what is
considered small constant string.
Shaves ~30kb (0.5%) from go executable.
This also updates test/prove.go to keep test case valid.
Change-Id: I99ae8871a1d00c96363c6d03d0b890782fa7e1d9
Reviewed-on: https://go-review.googlesource.com/38776
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Diffstat (limited to 'test/prove.go')
| -rw-r--r-- | test/prove.go | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/test/prove.go b/test/prove.go index 5f4de604c6..e89ab3f8d8 100644 --- a/test/prove.go +++ b/test/prove.go @@ -250,7 +250,9 @@ func f9(a, b bool) int { func f10(a string) int { n := len(a) - if a[:n>>1] == "aaaaaaaaaaaaaa" { + // We optimize comparisons with small constant strings (see cmd/compile/internal/gc/walk.go), + // so this string literal must be long. + if a[:n>>1] == "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" { return 0 } return 1 |