Martin Möhrmann
a8a60ac2a7
cmd/compile: optimize append(x, make([]T, y)...) slice extension
...
Changes the compiler to recognize the slice extension pattern
append(x, make([]T, y)...)
and replace it with growslice and an optional memclr to avoid an allocation for make([]T, y).
Memclr is not called in case growslice already allocated a new cleared backing array
when T contains pointers.
amd64:
name old time/op new time/op delta
ExtendSlice/IntSlice 103ns ± 4% 57ns ± 4% -44.55% (p=0.000 n=18+18)
ExtendSlice/PointerSlice 155ns ± 3% 77ns ± 3% -49.93% (p=0.000 n=20+20)
ExtendSlice/NoGrow 50.2ns ± 3% 5.2ns ± 2% -89.67% (p=0.000 n=18+18)
name old alloc/op new alloc/op delta
ExtendSlice/IntSlice 64.0B ± 0% 32.0B ± 0% -50.00% (p=0.000 n=20+20)
ExtendSlice/PointerSlice 64.0B ± 0% 32.0B ± 0% -50.00% (p=0.000 n=20+20)
ExtendSlice/NoGrow 32.0B ± 0% 0.0B -100.00% (p=0.000 n=20+20)
name old allocs/op new allocs/op delta
ExtendSlice/IntSlice 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=20+20)
ExtendSlice/PointerSlice 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=20+20)
ExtendSlice/NoGrow 1.00 ± 0% 0.00 -100.00% (p=0.000 n=20+20)
Fixes #21266
Change-Id: Idc3077665f63cbe89762b590c5967a864fd1c07f
Reviewed-on: https://go-review.googlesource.com/109517
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2018-05-06 04:28:23 +00:00
Rob Pike
fc0dc04095
test: [a-c]: add introductory comments to tests
...
Very few of the compiler regression tests include a comment
saying waht they do. Many are obvious, some are anything but.
I've started with a-c in the top directory. More will follow once
we agree on the approach, correctness, and thoroughness here.
zerodivide.go sneaked in too.
R=rsc, r
CC=golang-dev
https://golang.org/cl/5656100
2012-02-19 13:19:43 +11:00
Russ Cox
0b477ef17e
test: use testlib (first 100)
...
X ,s;^// \$G (\$D/)?\$F\.go *$;// compile;g
X ,s;^// \$G (\$D/)?\$F\.go && \$L \$F\.\$A *$;// build;g
X ,s;^// \$G (\$D/)?\$F\.go && \$L \$F\.\$A && \./\$A\.out *$;// run;g
X ,s;^// errchk \$G( -e)? (\$D/)?\$F\.go *$;// errorcheck;g
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5656082
2012-02-16 23:48:57 -05:00
Ian Lance Taylor
3692726f32
test: test append with two different named types with same element type
...
R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5615045
2012-02-01 15:24:15 -08:00
Luuk van Dijk
77fac21e82
runtime: append([]byte, string...)
...
Fixes #2274
R=rsc, gri, dsymonds, bradfitz, lvd
CC=golang-dev
https://golang.org/cl/5149045
2011-10-12 15:59:23 +02:00
Russ Cox
f2b5a07453
delete float, complex - code changes
...
also:
cmplx -> complex
float64(1.0) -> 1.0
float64(1) -> 1.0
R=gri, r, gri1, r2
CC=golang-dev
https://golang.org/cl/3991043
2011-01-19 23:09:00 -05:00
Robert Griesemer
e79ebb008f
test for append() built-in
...
R=r, rsc
CC=golang-dev
https://golang.org/cl/2777041
2010-10-28 08:14:31 -07:00
