tree 12f95245ff506b61b1478aa8a9dcac28cdfdb3c0
parent 0e4aa31b26a20b6a6a2ca102b85ba8c8b8cdf876
author Cherry Zhang <cherryyz@google.com> 1560649666 -0400
committer Ian Lance Taylor <iant@golang.org> 1560957198 +0000

compiler: optimize string concatenations

runtime.concatstring{2,3,4,5} are just wrappers of concatstrings.
These wrappers don't provide any benefit, at least in the C
calling convention we use, where passing arrays by value isn't an
efficient thing. Change it to always use concatstrings.

Also, the cap field of the slice passed to concatstrings is not
necessary. So change it to pass a pointer and a length directly,
which is more efficient than passing a slice header by value.

Change-Id: I068a5cc83f938d3fa936b8fa5a064aaa0a42d9d1
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/182539
Reviewed-by: Ian Lance Taylor <iant@golang.org>