qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-09-25 15:10:11 -06:00
Code Releases Activity

runtime: check pointer equality in arm64 cmpbody

Browse Source 
Updates #11336

Follow the lead of amd64 by doing a pointer equality check
before comparing string/byte contents on arm64.

BenchmarkCompareBytesEqual-8               25.8           26.3           +1.94%
BenchmarkCompareBytesToNil-8               9.59           9.59           +0.00%
BenchmarkCompareBytesEmpty-8               9.59           9.17           -4.38%
BenchmarkCompareBytesIdentical-8           26.3           9.17           -65.13%
BenchmarkCompareBytesSameLength-8          16.3           16.3           +0.00%
BenchmarkCompareBytesDifferentLength-8     16.3           16.3           +0.00%
BenchmarkCompareBytesBigUnaligned-8        1132038        1131409        -0.06%
BenchmarkCompareBytesBig-8                 1126758        1128470        +0.15%
BenchmarkCompareBytesBigIdentical-8        1084366        9.17           -100.00%

Change-Id: Id7125c31957eff1ddb78897d4511bd50e79af3f7
Reviewed-on: https://go-review.googlesource.com/13885
Reviewed-by: Keith Randall <khr@golang.org>
This commit is contained in:
Dave Cheney 2015-08-25 13:12:32 +10:00
parent 3efe36d4c4
commit 686d44d9e0
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/runtime/asm_arm64.s
View File

@ -870,6 +870,8 @@ TEXT bytes·Compare(SB),NOSPLIT,$-4-56
// On exit:
// R4, R5, and R6 are clobbered
TEXT runtime·cmpbody<>(SB),NOSPLIT,$-4-0
CMP R2, R3
BEQ samebytes // same starting pointers; compare lengths
CMP R0, R1
CSEL LT, R1, R0, R6 // R6 is min(R0, R1)