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| author | Josh Bleecher Snyder <josharian@gmail.com> | 2017-07-16 17:46:52 -1000 |
|---|---|---|
| committer | Josh Bleecher Snyder <josharian@gmail.com> | 2017-08-14 23:32:03 +0000 |
| commit | 29e9b89b9ada73fa7775b351c100709c330c0a46 (patch) | |
| tree | e5ba3ae68b465dcca720be7bec91410ddf059d16 /src | |
| parent | 733567a1860956e87daa1a2fa46d58fc44b896cc (diff) | |
| download | go-29e9b89b9ada73fa7775b351c100709c330c0a46.tar.xz | |
runtime: special case allocation of arrays of size 1
This avoids division and multiplication.
Instrumentation suggests that this is a very common case.
Change-Id: I2d5d5012d4f4df4c4af1f9f85ca9c323c9889c0e
Reviewed-on: https://go-review.googlesource.com/54657
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/runtime/malloc.go | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go index 0ebd2c0ab2..274ab537fc 100644 --- a/src/runtime/malloc.go +++ b/src/runtime/malloc.go @@ -847,6 +847,9 @@ func reflect_unsafe_New(typ *_type) unsafe.Pointer { // newarray allocates an array of n elements of type typ. func newarray(typ *_type, n int) unsafe.Pointer { + if n == 1 { + return mallocgc(typ.size, typ, true) + } if n < 0 || uintptr(n) > maxSliceCap(typ.size) { panic(plainError("runtime: allocation size out of range")) } |