Copies utf8 constants and EncodeRune implementation from unicode/utf8.
Adds a new decoderune implementation that is used by the compiler
in code generated for ranging over strings. It does not handle
ASCII runes since these are handled directly before calls to decoderune.
The DecodeRuneInString implementation from unicode/utf8 is not used
since it uses a lookup table that would increase the use of cpu caches.
Adds more tests that check decoding of valid and invalid utf8 sequences.
name old time/op new time/op delta
RuneIterate/range2/ASCII-4 7.45ns ± 2% 7.45ns ± 1% ~ (p=0.634 n=16+16)
RuneIterate/range2/Japanese-4 53.5ns ± 1% 49.2ns ± 2% -8.03% (p=0.000 n=20+20)
RuneIterate/range2/MixedLength-4 46.3ns ± 1% 41.0ns ± 2% -11.57% (p=0.000 n=20+20)
new:
"".decoderune t=1 size=423 args=0x28 locals=0x0
old:
"".charntorune t=1 size=666 args=0x28 locals=0x0
Change-Id: I1df1fdb385bb9ea5e5e71b8818ea2bf5ce62de52
Reviewed-on: https://go-review.googlesource.com/28490
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
when not instrumenting:
- Intrinsify uses of slicebytetostringtmp within the runtime package
in the ssa backend.
- Pass OARRAYBYTESTRTMP nodes to the compiler backends for lowering
instead of generating calls to slicebytetostringtmp.
name old time/op new time/op delta
ConcatStringAndBytes-4 27.9ns ± 2% 24.7ns ± 2% -11.52% (p=0.000 n=43+43)
Fixes#17044
Change-Id: I51ce9c3b93284ce526edd0234f094e98580faf2d
Reviewed-on: https://go-review.googlesource.com/29017
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Before this CL the runtime prevented printing of overlong strings with the print
function when the length of the string was determined to be corrupted.
Corruption was checked by comparing the string size against the limit
which was stored in maxstring.
However maxstring was not updated everywhere were go strings were created
e.g. for string constants during compile time. Thereby the check for maximum
string length prevented the printing of some valid strings.
The protection maxstring provided did not warrant the bookkeeping
and global synchronization needed to keep maxstring updated to the
correct limit everywhere.
Fixes#16999
Change-Id: I62cc2f4362f333f75b77f199ce1a71aac0ff7aeb
Reviewed-on: https://go-review.googlesource.com/28813
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Generate a for loop for ranging over strings that only needs to call
the runtime function charntorune for non ASCII characters.
This provides faster iteration over ASCII characters and slightly
faster iteration for other characters.
The runtime function charntorune is changed to take an index from where
to start decoding and returns the index after the last byte belonging
to the decoded rune.
All call sites of charntorune in the runtime are replaced by a for loop
that will be transformed by the compiler instead of calling the charntorune
function directly.
go binary size decreases by 80 bytes.
godoc binary size increases by around 4 kilobytes.
runtime:
name old time/op new time/op delta
RuneIterate/range/ASCII-4 43.7ns ± 3% 10.3ns ± 4% -76.33% (p=0.000 n=44+45)
RuneIterate/range/Japanese-4 72.5ns ± 2% 62.8ns ± 2% -13.41% (p=0.000 n=49+50)
RuneIterate/range1/ASCII-4 43.5ns ± 2% 10.4ns ± 3% -76.18% (p=0.000 n=50+50)
RuneIterate/range1/Japanese-4 72.5ns ± 2% 62.9ns ± 2% -13.26% (p=0.000 n=50+49)
RuneIterate/range2/ASCII-4 43.5ns ± 3% 10.3ns ± 2% -76.22% (p=0.000 n=48+47)
RuneIterate/range2/Japanese-4 72.4ns ± 2% 62.7ns ± 2% -13.47% (p=0.000 n=50+50)
strings:
name old time/op new time/op delta
IndexRune-4 64.7ns ± 5% 22.4ns ± 3% -65.43% (p=0.000 n=25+21)
MapNoChanges-4 269ns ± 2% 157ns ± 2% -41.46% (p=0.000 n=23+24)
Fields-4 23.0ms ± 2% 19.7ms ± 2% -14.35% (p=0.000 n=25+25)
FieldsFunc-4 23.1ms ± 2% 19.6ms ± 2% -14.94% (p=0.000 n=25+24)
name old speed new speed delta
Fields-4 45.6MB/s ± 2% 53.2MB/s ± 2% +16.87% (p=0.000 n=24+25)
FieldsFunc-4 45.5MB/s ± 2% 53.5MB/s ± 2% +17.57% (p=0.000 n=25+24)
Updates #13162
Change-Id: I79ffaf828d82bf9887592f08e5cad883e9f39701
Reviewed-on: https://go-review.googlesource.com/27853
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Martin Möhrmann <martisch@uos.de>
Zero the entire buffer so we don't need to
lower its capacity upon return. This lets callers
do some appending without allocation.
Zeroing is cheap, the byte buffer requires only
4 extra instructions.
Fixes#14235
Change-Id: I970d7badcef047dafac75ac17130030181f18fe2
Reviewed-on: https://go-review.googlesource.com/22424
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.
This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:
$ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])')
$ go test go/doc -update
Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
They do the same thing, except memequal also has the short-circuit
check if the two pointers are equal.
A) We might as well always do the short-circuit check, it is only 2 instructions.
B) The extra function call (memequal->memeq) is expensive.
benchmark old ns/op new ns/op delta
BenchmarkArrayEqual-8 8.56 5.31 -37.97%
No noticeable affect on the former memeq user (maps).
Fixes#14302
Change-Id: I85d1ada59ed11e64dd6c54667f79d32cc5f81948
Reviewed-on: https://go-review.googlesource.com/19843
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
When using a stack-allocated buffer for the result, don't
expose the uninitialized portion of it by restricting its
capacity to its length.
The other option is to zero the portion between len and cap.
That seems like more work, but might be worth it if the caller
then appends some stuff to the result. But this close to 1.6,
I'm inclined to do the simplest fix possible.
Fixes#14232
Change-Id: I21c50d3cda02fd2df4d60ba5e2cfe2efe272f333
Reviewed-on: https://go-review.googlesource.com/19231
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Now there are just three programs to compile instead of many,
and repeated tests can reuse the compilation result instead of
rebuilding it.
Combined, these changes reduce the time spent testing runtime
during all.bash on my laptop from about 60 to about 30 seconds.
(All.bash itself runs in 5½ minutes.)
For #10571.
Change-Id: Ie2c1798b847f1a635a860d11dcdab14375319ae9
Reviewed-on: https://go-review.googlesource.com/18085
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
Using benchmark from the issue:
benchmark old ns/op new ns/op delta
BenchmarkRangeStringCast 2162 1152 -46.72%
benchmark old allocs new allocs delta
BenchmarkRangeStringCast 1 0 -100.00%
Fixes#2204
Change-Id: I92c5edd2adca4a7b6fba00713a581bf49dc59afe
Reviewed-on: https://go-review.googlesource.com/3790
Reviewed-by: Keith Randall <khr@golang.org>
If result of string(i) does not escape,
allocate a [4]byte temp on stack for it.
Change-Id: If31ce9447982929d5b3b963fd0830efae4247c37
Reviewed-on: https://go-review.googlesource.com/3411
Reviewed-by: Russ Cox <rsc@golang.org>
Currently we always allocate string buffers in heap.
For example, in the following code we allocate a temp string
just for comparison:
if string(byteSlice) == "abc" { ... }
This change extends escape analysis to cover []byte->string
conversions and string concatenation. If the result of operations
does not escape, compiler allocates a small buffer
on stack and passes it to slicebytetostring and concatstrings.
Then runtime uses the buffer if the result fits into it.
Size of the buffer is 32 bytes. There is no fundamental theory
behind this number. Just an observation that on std lib
tests/benchmarks frequency of string allocation is inversely
proportional to string length; and there is significant number
of allocations up to length 32.
benchmark old allocs new allocs delta
BenchmarkFprintfBytes 2 1 -50.00%
BenchmarkDecodeComplex128Slice 318 316 -0.63%
BenchmarkDecodeFloat64Slice 318 316 -0.63%
BenchmarkDecodeInt32Slice 318 316 -0.63%
BenchmarkDecodeStringSlice 2318 2316 -0.09%
BenchmarkStripTags 11 5 -54.55%
BenchmarkDecodeGray 111 102 -8.11%
BenchmarkDecodeNRGBAGradient 200 188 -6.00%
BenchmarkDecodeNRGBAOpaque 165 152 -7.88%
BenchmarkDecodePaletted 319 309 -3.13%
BenchmarkDecodeRGB 166 157 -5.42%
BenchmarkDecodeInterlacing 279 268 -3.94%
BenchmarkGoLookupIP 153 135 -11.76%
BenchmarkGoLookupIPNoSuchHost 508 466 -8.27%
BenchmarkGoLookupIPWithBrokenNameServer 245 226 -7.76%
BenchmarkClientServerParallel4 62 61 -1.61%
BenchmarkClientServerParallel64 62 61 -1.61%
BenchmarkClientServerParallelTLS4 79 78 -1.27%
BenchmarkClientServerParallelTLS64 112 111 -0.89%
benchmark old ns/op new ns/op delta
BenchmarkFprintfBytes 381 311 -18.37%
BenchmarkStripTags 2615 2351 -10.10%
BenchmarkDecodeNRGBAGradient 3715887 3635096 -2.17%
BenchmarkDecodeNRGBAOpaque 3047645 2928644 -3.90%
BenchmarkGoLookupIP 153 135 -11.76%
BenchmarkGoLookupIPNoSuchHost 508 466 -8.27%
Change-Id: I9ec01da816945c3329d7be3c7794b520418c3f99
Reviewed-on: https://go-review.googlesource.com/3120
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Currently we allocate a new string during []byte->string conversion
in string comparison expressions. String allocation is unnecessary in
this case, because comparison does memorize the strings for later use.
This change uses slicebytetostringtmp to construct temp string directly
from []byte buffer and passes it to runtime.eqstring.
Change-Id: If00f1faaee2076baa6f6724d245d5b5e0f59b563
Reviewed-on: https://go-review.googlesource.com/3410
Reviewed-by: Russ Cox <rsc@golang.org>
