| Age | Commit message (Collapse) | Author |
|---|
|
Makes sure the copyright notice is not interpreted as the package level
godoc.
Change-Id: I2afce7c9d620f19d51ec1438b1d0db1774b57146
Reviewed-on: https://go-review.googlesource.com/c/go/+/248760
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
|
|
match:
m = make([]T, x); copy(m, s)
for pointer free T and x==len(s) rewrite to:
m = mallocgc(x*elemsize(T), nil, false); memmove(&m, &s, x*elemsize(T))
otherwise rewrite to:
m = makeslicecopy([]T, x, s)
This avoids memclear and shading of pointers in the newly created slice
before the copy.
With this CL "s" is only be allowed to bev a variable and not a more
complex expression. This restriction could be lifted in future versions
of this optimization when it can be proven that "s" is not referencing "m".
Triggers 450 times during make.bash..
Reduces go binary size by ~8 kbyte.
name old time/op new time/op delta
MakeSliceCopy/mallocmove/Byte 71.1ns ± 1% 65.8ns ± 0% -7.49% (p=0.000 n=10+9)
MakeSliceCopy/mallocmove/Int 71.2ns ± 1% 66.0ns ± 0% -7.27% (p=0.000 n=10+8)
MakeSliceCopy/mallocmove/Ptr 104ns ± 4% 99ns ± 1% -5.13% (p=0.000 n=10+10)
MakeSliceCopy/makecopy/Byte 70.3ns ± 0% 68.0ns ± 0% -3.22% (p=0.000 n=10+9)
MakeSliceCopy/makecopy/Int 70.3ns ± 0% 68.5ns ± 1% -2.59% (p=0.000 n=9+10)
MakeSliceCopy/makecopy/Ptr 102ns ± 0% 99ns ± 1% -2.97% (p=0.000 n=9+9)
MakeSliceCopy/nilappend/Byte 75.4ns ± 0% 74.9ns ± 2% -0.63% (p=0.015 n=9+9)
MakeSliceCopy/nilappend/Int 75.6ns ± 0% 76.4ns ± 3% ~ (p=0.245 n=9+10)
MakeSliceCopy/nilappend/Ptr 107ns ± 0% 108ns ± 1% +0.93% (p=0.005 n=9+10)
Fixes #26252
Change-Id: Iec553dd1fef6ded16197216a472351c8799a8e71
Reviewed-on: https://go-review.googlesource.com/c/go/+/146719
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
|
|
This improves performance for slices with an element size larger
than 32 bytes and removes loading a value from the maxElems
array for smaller element sizes.
name old time/op new time/op delta
MakeSlice/Byte 18.0ns ± 4% 18.0ns ± 2% ~ (p=0.575 n=20+17)
MakeSlice/Int16 21.8ns ± 2% 21.6ns ± 1% -0.63% (p=0.035 n=20+19)
MakeSlice/Int 42.0ns ± 2% 41.6ns ± 1% ~ (p=0.121 n=20+18)
MakeSlice/Ptr 62.6ns ± 2% 62.4ns ± 2% ~ (p=0.491 n=20+18)
MakeSlice/Struct/24 57.4ns ± 3% 56.0ns ± 2% -2.40% (p=0.000 n=19+19)
MakeSlice/Struct/32 62.1ns ± 2% 60.6ns ± 3% -2.43% (p=0.000 n=20+20)
MakeSlice/Struct/40 77.3ns ± 3% 68.9ns ± 3% -10.91% (p=0.000 n=20+20)
Updates #21588
Change-Id: Ie12807bf8f77c0e15453413f47e3d7de771b798f
Reviewed-on: https://go-review.googlesource.com/c/142377
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
|
|
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>
|
|
Add a special case for power-of-2 sized elements.
We can replace div/mul with left/right shift and avoid expensive operation.
growslice is hotter for short slices of small elements, such as int16, so
add an int16 version for GrowSlice benchmark.
name old time/op new time/op delta
GrowSlice/Byte-6 61.3ns ± 3% 60.5ns ± 4% -1.33% (p=0.002 n=30+30)
GrowSlice/Int16-6 94.0ns ± 4% 84.7ns ± 2% -9.82% (p=0.000 n=30+30)
GrowSlice/Int-6 100ns ± 1% 99ns ± 1% -0.25% (p=0.032 n=29+28)
GrowSlice/Ptr-6 197ns ± 2% 195ns ± 2% -0.94% (p=0.001 n=30+29)
GrowSlice/Struct/24-6 168ns ± 1% 166ns ± 2% -1.09% (p=0.000 n=25+30)
GrowSlice/Struct/32-6 187ns ± 2% 180ns ± 1% -3.59% (p=0.000 n=30+30)
GrowSlice/Struct/40-6 241ns ± 2% 238ns ± 2% -1.41% (p=0.000 n=30+30)
Change-Id: I31e8388d73fd9356e2dcc091d8d92eef3e3ccdbc
Reviewed-on: https://go-review.googlesource.com/102279
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
|
|
The runtime builtin functions that are tested in append_test.go
are defined in slice.go. Renaming the test file to slice_test.go
makes this relation explicit with a common file name prefix.
Change-Id: I2f89ec23a6077fe6b80d2161efc760df828c8cd4
Reviewed-on: https://go-review.googlesource.com/90655
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
|
