commit 045dbeaf053f0c78941a11140e5a877237ccc489
author Rémy Oudompheng <oudomphe@phare.normalesup.org> Mon Sep 16 20:31:21 2013 -0400
committer Russ Cox <rsc@golang.org> Mon Sep 16 20:31:21 2013 -0400
tree 61a21dc187ba93e8feb0df2d85fa3127ed665590
parent 00061219f03d666e93947a3cb326256062a7a92c

cmd/gc, runtime: inline append in frontend.

A new transformation during walk turns append calls
into a combination of growslice and memmove.

benchmark                     old ns/op    new ns/op    delta
BenchmarkAppend                     141          141   +0.00%
BenchmarkAppend1Byte                 18           11  -39.56%
BenchmarkAppend4Bytes                19           10  -42.63%
BenchmarkAppend7Bytes                18           10  -42.16%
BenchmarkAppend8Bytes                18           10  -40.44%
BenchmarkAppend15Bytes               19           11  -41.67%
BenchmarkAppend16Bytes               19           11  -41.97%
BenchmarkAppend32Bytes               23           14  -38.82%
BenchmarkAppendStr1Byte              14           10  -23.78%
BenchmarkAppendStr4Bytes             14           11  -21.13%
BenchmarkAppendStr8Bytes             14           10  -25.17%
BenchmarkAppendStr16Bytes            19           11  -41.45%
BenchmarkAppendStr32Bytes            18           14  -19.44%
BenchmarkAppendSpecialCase           62           63   +1.77%

R=golang-dev, khr, cshapiro, rsc, dave
CC=golang-dev
https://golang.org/cl/12815046