Commit Graph

7860 Commits

Author SHA1 Message Date
Dmitriy Vyukov 828c68f8d8 undo CL 9805043 / 776aba85ece8
multiple failures on amd64

««« original CL description
runtime: introduce helper persistentalloc() function
It is a caching wrapper around SysAlloc() that can allocate small chunks.
Use it for symtab allocations. Reduces number of symtab walks from 4 to 3
(reduces buildfuncs time from 10ms to 7.5ms on a large binary,
reduces initial heap size by 680K on the same binary).
Also can be used for type info allocation, itab allocation.
There are also several places in GC where we do the same thing,
they can be changed to use persistentalloc().
Also can be used in FixAlloc, because each instance of FixAlloc allocates
in 128K regions, which is too eager.

R=golang-dev, daniel.morsing, khr
CC=golang-dev
https://golang.org/cl/9805043
»»»

R=golang-dev
CC=golang-dev
https://golang.org/cl/9822043
2013-05-28 11:14:39 +04:00
Dmitriy Vyukov 5166013f75 runtime: inline MCache_Alloc() into mallocgc()
benchmark                    old ns/op    new ns/op    delta
BenchmarkMalloc8                    68           62   -8.63%
BenchmarkMalloc16                   75           69   -7.94%
BenchmarkMallocTypeInfo8           102           98   -3.73%
BenchmarkMallocTypeInfo16          108          103   -4.63%

R=golang-dev, dave, khr
CC=golang-dev
https://golang.org/cl/9790043
2013-05-28 11:05:55 +04:00
Dmitriy Vyukov 47e0a3d7b1 runtime: introduce helper persistentalloc() function
It is a caching wrapper around SysAlloc() that can allocate small chunks.
Use it for symtab allocations. Reduces number of symtab walks from 4 to 3
(reduces buildfuncs time from 10ms to 7.5ms on a large binary,
reduces initial heap size by 680K on the same binary).
Also can be used for type info allocation, itab allocation.
There are also several places in GC where we do the same thing,
they can be changed to use persistentalloc().
Also can be used in FixAlloc, because each instance of FixAlloc allocates
in 128K regions, which is too eager.

R=golang-dev, daniel.morsing, khr
CC=golang-dev
https://golang.org/cl/9805043
2013-05-28 10:47:35 +04:00
Bill Neubauer 82ef961af5 runtime: fix runtime·netpoll() to call runtime·netpollready() only once per event.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/9808043
2013-05-28 05:03:10 +08:00
Shenghou Ma ae73b90369 runtime: make arm signal handler call runtime.badsignal
In preparation for CL 9249043 (already submitted).

Fixes #5553.

R=golang-dev, iant, capnm9, dave
CC=golang-dev
https://golang.org/cl/9251043
2013-05-27 20:46:53 +08:00
Dmitriy Vyukov 5782f4117d runtime: introduce cnewarray() to simplify allocation of typed arrays
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/9648044
2013-05-27 11:29:11 +04:00
Jan Ziak e017e0cb24 runtime: flag static variables as no-pointers
Variables in data sections of 32-bit executables interfere with
garbage collector's ability to free objects and/or unnecessarily
slow down the garbage collector.

This changeset moves some static variables to .noptr sections.
'files' in symtab.c is now allocated dynamically.

R=golang-dev, dvyukov, minux.ma
CC=golang-dev
https://golang.org/cl/9786044
2013-05-27 08:11:59 +02:00
Dmitriy Vyukov 46137f227b runtime: update comment on stack allocator
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/9665046
2013-05-25 22:47:36 +04:00
Rob Pike 7472ce0e58 fmt.Printf: introduce notation for random access to arguments.
This text is added to doc.go:

        Explicit argument indexes:

        In Printf, Sprintf, and Fprintf, the default behavior is for each
        formatting verb to format successive arguments passed in the call.
        However, the notation [n] immediately before the verb indicates that the
        nth one-indexed argument is to be formatted instead. The same notation
        before a '*' for a width or precision selects the argument index holding
        the value. After processing a bracketed expression [n], arguments n+1,
        n+2, etc. will be processed unless otherwise directed.

        For example,
                fmt.Sprintf("%[2]d %[1]d\n", 11, 22)
        will yield "22, 11", while
                fmt.Sprintf("%[3]*[2].*[1]f", 12.0, 2, 6),
        equivalent to
                fmt.Sprintf("%6.2f", 12.0),
        will yield " 12.00". Because an explicit index affects subsequent verbs,
        this notation can be used to print the same values multiple times
        by resetting the index for the first argument to be repeated:
                fmt.Sprintf("%d %d %#[1]x %#x", 16, 17)
        will yield "16 17 0x10 0x11".

The notation chosen differs from that in C, but I believe it's easier to read
and to remember (we're indexing the arguments), and compatibility with
C's printf was never a strong goal anyway.

While we're here, change the word "field" to "arg" or "argument" in the
code; it was being misused and was confusing.

R=rsc, bradfitz, rogpeppe, minux.ma, peter.armitage
CC=golang-dev
https://golang.org/cl/9680043
2013-05-24 15:49:26 -07:00
Adam Langley ddc8679128 crypto/x509: harmonise error prefixes.
crypto/x509 has ended up with a variety of error formats. This change makes them all start with "x509: ".

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/9736043
2013-05-24 16:23:13 -04:00
Christopher Nielsen ee78a707c0 path/filepath: Skip TestEvalSymlinks. Plan 9 doesn't have symlinks.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/9713044
2013-05-24 11:01:04 -07:00
Gerasimos Dimitriadis af48543c54 asn1: Stricter checks for DER encoded booleans
According to X.690, only 0 and 255 are allowed as values
for encoded booleans. Also added some test for parsing
booleans

R=golang-dev, agl, r
CC=golang-dev
https://golang.org/cl/9692043
2013-05-24 12:37:42 -04:00
Dmitriy Vyukov 0806c97209 log/syslog: fix deadlock in test
The problem was that server handlers block on done<-,
the goroutine that reads from done blocks on count<-,
and the main goroutine that is supposed to read from count
waits for server handlers to exit.
Fixes #5547.

R=golang-dev, dave, bradfitz
CC=golang-dev
https://golang.org/cl/9722043
2013-05-24 18:35:48 +04:00
Frederick Kelly Mayle III 7b9df09261 runtime: faster range on empty map
benchmark                old ns/op    new ns/op    delta
BenchmarkMapIter               191          190   -0.52%
BenchmarkMapIterEmpty           22            4  -78.96%

R=golang-dev, minux.ma, dvyukov, iant, khr
CC=golang-dev
https://golang.org/cl/9637043
2013-05-23 14:17:52 -07:00
Daniel Morsing fdc4ce6ec7 io: Prioritize WriterTos over ReaderFroms in Copy.
This only affects calls where both ReaderFrom and WriterTo are implemented. WriterTo can issue one large write, while ReaderFrom must Read until EOF, potentially reallocating when out of memory. With one large Write, the Writer only needs to allocate once.

This also helps in ioutil.Discard since we can avoid copying memory when the Reader implements WriterTo.

R=golang-dev, dsymonds, remyoudompheng, bradfitz
CC=golang-dev, minux.ma
https://golang.org/cl/9462044
2013-05-23 18:29:19 +02:00
Nan Deng 876455f3ba crypto/rsa: implement PSS signatures.
This change contains an implementation of the RSASSA-PSS signature
algorithm described in RFC 3447.

R=agl, agl
CC=gobot, golang-dev, r
https://golang.org/cl/9438043
2013-05-23 11:10:41 -04:00
Mikio Hara adbe59e332 syscall: add IPv6 socket options for Unix variants
This CL adds missing IPv6 socket options which are required
to control IPv6 as described in RFC 3493, RFC 3542.

Update #5538

R=golang-dev, dave, iant
CC=golang-dev
https://golang.org/cl/9373046
2013-05-23 16:22:05 +09:00
Robert Griesemer e3a72b05f8 go/doc: fix build
1) go/doc:
   - create correct ast.FuncType
   - use more commonly used variable names in a test case

2) make ast.FuncType.Pos robust in case of incorrect ASTs

R=golang-dev
CC=golang-dev
https://golang.org/cl/9651044
2013-05-22 14:22:50 -07:00
Shenghou Ma cb8782e8b3 bufio: fix SplitFunc docs
Fixes #5532.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/9672044
2013-05-23 04:38:32 +08:00
Robert Griesemer 75b62e367b go/ast: fix FuncType.Pos() impl. and FuncType.Params documentation
As pointed out by adonovan.

R=golang-dev, adonovan
CC=golang-dev
https://golang.org/cl/9662045
2013-05-22 13:36:43 -07:00
Rob Pike e17a6d4b9d log/syslog: report errors from write
Fixes #5541.
This time for sure.

R=golang-dev, minux.ma, iant
CC=golang-dev
https://golang.org/cl/9668043
2013-05-22 12:45:52 -07:00
Dmitriy Vyukov 72c4ee1a9d runtime: properly synchronize GC and finalizer goroutine
This is needed for preemptive scheduler, because the goroutine
can be preempted at surprising points.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/9376043
2013-05-22 23:04:46 +04:00
Dmitriy Vyukov 34c67eb24e runtime: detect deadlocks in programs using cgo
When cgo is used, runtime creates an additional M to handle callbacks on threads not created by Go.
This effectively disabled deadlock detection, which is a right thing, because Go program can be blocked
and only serve callbacks on external threads.
This also disables deadlock detection under race detector, because it happens to use cgo.
With this change the additional M is created lazily on first cgo call. So deadlock detector
works for programs that import "C", "net" or "net/http/pprof" but do not use them in fact.
Also fixes deadlock detector under race detector.
It should be fine to create the M later, because C code can not call into Go before first cgo call,
because C code does not know when Go initialization has completed. So a Go program need to call into C
first either to create an external thread, or notify a thread created in global ctor that Go
initialization has completed.
Fixes #4973.
Fixes #5475.

R=golang-dev, minux.ma, iant
CC=golang-dev
https://golang.org/cl/9303046
2013-05-22 22:57:47 +04:00
Rob Pike f6c7b339a6 undo CL 9658043 / ac7877558dce
The original code was correct. The count returned must be the length
of the input slice, not the length of the formatted message.

««« original CL description
log/syslog: report errors from Fprintf
Thanks to chiparus for identifying this.

Fixes #5541.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/9658043
»»»

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/9644044
2013-05-22 11:42:04 -07:00
Dmitriy Vyukov c075d82cca runtime: fix and speedup malloc stats
Currently per-sizeclass stats are lost for destroyed MCache's. This patch fixes this.
Also, only update mstats.heap_alloc on heap operations, because that's the only
stat that needs to be promptly updated. Everything else needs to be up-to-date only in ReadMemStats().

R=golang-dev, remyoudompheng, dave, iant
CC=golang-dev
https://golang.org/cl/9207047
2013-05-22 22:22:57 +04:00
Rob Pike 4c2df76b7d log/syslog: report errors from Fprintf
Thanks to chiparus for identifying this.

Fixes #5541.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/9658043
2013-05-22 11:03:10 -07:00
Dmitriy Vyukov c4cfef075e runtime: simplify MCache
The nlistmin/size thresholds are copied from tcmalloc,
but are unnecesary for Go malloc. We do not do explicit
frees into MCache. For sparse cases when we do (mainly hashmap),
simpler logic will do.

R=rsc, dave, iant
CC=gobot, golang-dev, r, remyoudompheng
https://golang.org/cl/9373043
2013-05-22 13:29:17 +04:00
Brad Fitzpatrick 950fa93531 net/http: add another Hijacker test
R=dsymonds
CC=gobot, golang-dev
https://golang.org/cl/9570043
2013-05-21 18:43:28 -07:00
Brad Fitzpatrick 99f6722860 bufio: reuse Writer buffers after Flush
A bufio.Writer.Flush marks the usual end of a Writer's
life. Recycle its internal buffer on those explicit flushes,
but not on normal, as-needed internal flushes.

benchmark               old ns/op    new ns/op    delta
BenchmarkWriterEmpty         1959          727  -62.89%

benchmark              old allocs   new allocs    delta
BenchmarkWriterEmpty            2            1  -50.00%

benchmark               old bytes    new bytes    delta
BenchmarkWriterEmpty         4215           83  -98.03%

R=gri, iant
CC=gobot, golang-dev, voidlogic7
https://golang.org/cl/9459044
2013-05-21 15:51:49 -07:00
Brad Fitzpatrick ddda7980c5 net/http: don't send Accept-Encoding on HEAD requests
Works around a bug in nginx: http://trac.nginx.org/nginx/ticket/358

Fixes #5522

R=iant
CC=gobot, golang-dev
https://golang.org/cl/9627043
2013-05-21 15:21:30 -07:00
Brad Fitzpatrick 0e10196982 database/sql: remove extra RemoveDep call
This should have been removed in 45c12efb4635. Not a correctness
issue, but unnecessary work.

This CL also adds paranoia checks in removeDep so this doesn't
happen again.

Fixes #5502

R=adg
CC=gobot, golang-dev, google
https://golang.org/cl/9543043
2013-05-21 14:58:08 -07:00
Brad Fitzpatrick 509a1173a3 time: remove Time.FormatAppend
undo CL 8478044 / 0d28fd55e721

Lack of consensus.

««« original CL description
time: add Time.FormatAppend

This is a version of Time.Format that doesn't require allocation.

Fixes #5192
Update #5195

R=r
CC=gobot, golang-dev
https://golang.org/cl/8478044
»»»

R=r
CC=golang-dev
https://golang.org/cl/9462049
2013-05-21 14:32:09 -07:00
Adam Langley 8590e1bd3c crypto/tls: don't send NPN extension if NextProtos is not set.
This isn't clearly a bug on Go's part, but it triggers a bug in Firefox
which means that crypto/tls and net/http cannot be wired up together
unless NextProtos includes "http/1.1". When net/http sets up the
tls.Config, it does this and so works fine. But anyone setting up the
tls.Config themselves will hit the Firefox bug.

Fixes #5445.

R=golang-dev, bradfitz, r
CC=golang-dev
https://golang.org/cl/9539045
2013-05-21 10:47:31 -04:00
Brad Fitzpatrick c6c439d7a0 net/http: use WriteString directly when possible
Several places used io.WriteString unnecessarily when the
static type already implemented WriteString. No need to
check for it at runtime.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/9608043
2013-05-20 19:26:26 -07:00
Rémy Oudompheng fc3bec386e cmd/gc: clear n->list of OFOR range loop after walk.
It contains the LHS of the range clause and gets
instrumented by racewalk, but it doesn't have any meaning.

Fixes #5446.

R=golang-dev, dvyukov, daniel.morsing, r
CC=golang-dev
https://golang.org/cl/9560044
2013-05-20 23:45:22 +02:00
Adam Langley b419e2b57c crypto/x509: provide better error messages for X.509 verify failures.
Failures caused by errors like invalid signatures or missing hash
functions cause rather generic, unhelpful error messages because no
trust chain can be constructed: "x509: certificate signed by unknown
authority."

With this change, authority errors may contain the reason why an
arbitary candidate step in the chain was rejected. For example, in the
event of a missing hash function the error looks like:

x509: certificate signed by unknown authority (possibly because of
"crypto/x509: cannot verify signature: algorithm unimplemented" while
trying to verify candidate authority certificate 'Thawte SGC CA')

Fixes 5058.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/9104051
2013-05-20 14:20:26 -04:00
Brad Fitzpatrick 27f7427995 net/http: simplify transfer body; reduces allocations too
benchmark                                   old ns/op    new ns/op    delta
BenchmarkServerFakeConnNoKeepAlive              14431        14247   -1.28%
BenchmarkServerFakeConnWithKeepAlive            11618        11357   -2.25%
BenchmarkServerFakeConnWithKeepAliveLite         6735         6427   -4.57%
BenchmarkServerHandlerTypeLen                    8842         8740   -1.15%
BenchmarkServerHandlerNoLen                      8001         7828   -2.16%
BenchmarkServerHandlerNoType                     8270         8227   -0.52%
BenchmarkServerHandlerNoHeader                   6148         5920   -3.71%

benchmark                                  old allocs   new allocs    delta
BenchmarkServerFakeConnNoKeepAlive                 30           29   -3.33%
BenchmarkServerFakeConnWithKeepAlive               25           24   -4.00%
BenchmarkServerFakeConnWithKeepAliveLite           10            9  -10.00%
BenchmarkServerHandlerTypeLen                      18           17   -5.56%
BenchmarkServerHandlerNoLen                        15           14   -6.67%
BenchmarkServerHandlerNoType                       16           15   -6.25%
BenchmarkServerHandlerNoHeader                     10            9  -10.00%

benchmark                                   old bytes    new bytes    delta
BenchmarkServerFakeConnNoKeepAlive               2557         2492   -2.54%
BenchmarkServerFakeConnWithKeepAlive             2260         2194   -2.92%
BenchmarkServerFakeConnWithKeepAliveLite         1092         1026   -6.04%
BenchmarkServerHandlerTypeLen                    1941         1875   -3.40%
BenchmarkServerHandlerNoLen                      1898         1832   -3.48%
BenchmarkServerHandlerNoType                     1906         1840   -3.46%
BenchmarkServerHandlerNoHeader                   1092         1026   -6.04%

Update #5195

R=golang-dev, daniel.morsing
CC=golang-dev
https://golang.org/cl/9492044
2013-05-20 07:23:59 -07:00
Mikio Hara b98a4d1a10 syscall: prefer PATH environment variable in bootstrap scripts
R=golang-dev, dave, iant
CC=golang-dev
https://golang.org/cl/9575043
2013-05-20 23:18:52 +09:00
Mikio Hara c5732c8526 runtime: integrated network poller for freebsd/amd64,386, openbsd/amd64,386
Update #5199

R=golang-dev, dvyukov
CC=golang-dev
https://golang.org/cl/8825043
2013-05-20 19:25:32 +09:00
Alex Brainman 1a948950f7 net: move system common global variables into fd_unix.go
R=golang-dev, bradfitz
CC=dvyukov, golang-dev, mikioh.mikioh
https://golang.org/cl/9495044
2013-05-20 15:23:45 +10:00
Dmitriy Vyukov 1308194204 runtime: zeroize g->fnstart to not prevent GC of the closure
Fixes #5493.

R=golang-dev, minux.ma, iant
CC=golang-dev
https://golang.org/cl/9557043
2013-05-20 08:17:21 +04:00
Brad Fitzpatrick d4cbc80d10 net/http: fewer allocations in the server path
Don't allocate for the Date or Content-Length headers.
A custom Date header formatter replaces use of time.Format.

benchmark                                   old ns/op    new ns/op    delta
BenchmarkClientServer                           67791        64424   -4.97%
BenchmarkClientServerParallel4                  62956        58533   -7.03%
BenchmarkClientServerParallel64                 62043        54789  -11.69%
BenchmarkServer                                254609       229060  -10.03%
BenchmarkServerFakeConnNoKeepAlive              17038        16316   -4.24%
BenchmarkServerFakeConnWithKeepAlive            14184        13226   -6.75%
BenchmarkServerFakeConnWithKeepAliveLite         8591         7532  -12.33%
BenchmarkServerHandlerTypeLen                   10750         9961   -7.34%
BenchmarkServerHandlerNoLen                      9535         8935   -6.29%
BenchmarkServerHandlerNoType                     9858         9362   -5.03%
BenchmarkServerHandlerNoHeader                   7754         6856  -11.58%

benchmark                                  old allocs   new allocs    delta
BenchmarkClientServer                              68           66   -2.94%
BenchmarkClientServerParallel4                     68           66   -2.94%
BenchmarkClientServerParallel64                    68           66   -2.94%
BenchmarkServer                                    21           19   -9.52%
BenchmarkServerFakeConnNoKeepAlive                 32           30   -6.25%
BenchmarkServerFakeConnWithKeepAlive               27           25   -7.41%
BenchmarkServerFakeConnWithKeepAliveLite           12           10  -16.67%
BenchmarkServerHandlerTypeLen                      19           18   -5.26%
BenchmarkServerHandlerNoLen                        17           15  -11.76%
BenchmarkServerHandlerNoType                       17           16   -5.88%
BenchmarkServerHandlerNoHeader                     12           10  -16.67%

Update #5195

R=nigeltao
CC=golang-dev
https://golang.org/cl/9432046
2013-05-19 20:15:40 -07:00
Alex Brainman 38abb09a2e runtime: change PollDesc.fd from int32 to uintptr
This is in preparation for netpoll windows version.

R=golang-dev, bradfitz
CC=dvyukov, golang-dev, mikioh.mikioh
https://golang.org/cl/9569043
2013-05-20 12:55:50 +10:00
Dmitriy Vyukov fee1d1cda0 runtime: properly set G status after syscall
R=golang-dev, r, dave
CC=golang-dev
https://golang.org/cl/9307045
2013-05-19 19:35:09 +04:00
Anthony Martin 2dc751ac21 runtime, cmd/gc: clean up function protoypes
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/8652043
2013-05-18 15:49:23 -07:00
Anthony Martin 8b85a3d480 runtime: mark usleep as NOSPLIT on Plan 9
Usleep is called from lockextra, also marked NOSPLIT.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/9258043
2013-05-18 15:47:49 -07:00
Anthony Martin b65271d008 runtime: fix newproc debugging print
R=golang-dev, remyoudompheng, r
CC=golang-dev
https://golang.org/cl/9249044
2013-05-18 15:47:15 -07:00
Keith Randall 28882bbd33 compress/flate: faster version of forwardCopy
benchmark                           old ns/op    new ns/op    delta
BenchmarkDecodeDigitsSpeed1e4          197767       203490   +2.89%
BenchmarkDecodeDigitsSpeed1e5         1873969      1912761   +2.07%
BenchmarkDecodeDigitsSpeed1e6        18922760     19021056   +0.52%
BenchmarkDecodeDigitsDefault1e4        194975       197054   +1.07%
BenchmarkDecodeDigitsDefault1e5       1704262      1719988   +0.92%
BenchmarkDecodeDigitsDefault1e6      16618354     16351957   -1.60%
BenchmarkDecodeDigitsCompress1e4       195281       194626   -0.34%
BenchmarkDecodeDigitsCompress1e5      1694364      1702372   +0.47%
BenchmarkDecodeDigitsCompress1e6     16463347     16492126   +0.17%
BenchmarkDecodeTwainSpeed1e4           200653       200127   -0.26%
BenchmarkDecodeTwainSpeed1e5          1861385      1759632   -5.47%
BenchmarkDecodeTwainSpeed1e6         18255769     17186679   -5.86%
BenchmarkDecodeTwainDefault1e4         189080       185157   -2.07%
BenchmarkDecodeTwainDefault1e5        1559222      1461465   -6.27%
BenchmarkDecodeTwainDefault1e6       14792125     13879051   -6.17%
BenchmarkDecodeTwainCompress1e4        188881       185151   -1.97%
BenchmarkDecodeTwainCompress1e5       1537031      1456945   -5.21%
BenchmarkDecodeTwainCompress1e6      14805972     13405094   -9.46%
BenchmarkPaeth                          4            4   -0.89%
BenchmarkDecodeGray                964679       937244   -2.84%
BenchmarkDecodeNRGBAGradient      3753769      3646416   -2.86%
BenchmarkDecodeNRGBAOpaque        3165856      2981300   -5.83%
BenchmarkDecodePaletted            713950       691984   -3.08%
BenchmarkDecodeRGB                3051718      2924260   -4.18%

R=nigeltao, bradfitz
CC=golang-dev, raph
https://golang.org/cl/9425046
2013-05-18 15:28:27 -07:00
Brad Fitzpatrick b25a53acd7 bufio: make Reader buffer transient
Share garbage between different bufio Readers. When a Reader
has zero buffered data, put its buffer into a pool.

This acknowledges that most bufio.Readers eventually get
read to completion, and their buffers are then no longer
needed.

benchmark               old ns/op    new ns/op    delta
BenchmarkReaderEmpty         2993         1058  -64.65%

benchmark              old allocs   new allocs    delta
BenchmarkReaderEmpty            3            2  -33.33%

benchmark               old bytes    new bytes    delta
BenchmarkReaderEmpty         4278          133  -96.89%

Update #5100

R=r
CC=adg, dvyukov, gobot, golang-dev, rogpeppe
https://golang.org/cl/8819049
2013-05-17 15:16:06 -07:00
Keith Randall 6021449236 runtime: faster x86 memmove (a.k.a. built-in copy())
REP instructions have a high startup cost, so we handle small
sizes with some straightline code.  The REP MOVSx instructions
are really fast for large sizes.  The cutover is approximately
1K.  We implement up to 128/256 because that is the maximum
SSE register load (loading all data into registers before any
stores lets us ignore copy direction).

(on a Sandy Bridge E5-1650 @ 3.20GHz)
benchmark               old ns/op    new ns/op    delta
BenchmarkMemmove0               3            3   +0.86%
BenchmarkMemmove1               5            5   +5.40%
BenchmarkMemmove2              18            8  -56.84%
BenchmarkMemmove3              18            7  -58.45%
BenchmarkMemmove4              36            7  -78.63%
BenchmarkMemmove5              36            8  -77.91%
BenchmarkMemmove6              36            8  -77.76%
BenchmarkMemmove7              36            8  -77.82%
BenchmarkMemmove8              18            8  -56.33%
BenchmarkMemmove9              18            7  -58.34%
BenchmarkMemmove10             18            7  -58.34%
BenchmarkMemmove11             18            7  -58.45%
BenchmarkMemmove12             36            7  -78.51%
BenchmarkMemmove13             36            7  -78.48%
BenchmarkMemmove14             36            7  -78.56%
BenchmarkMemmove15             36            7  -78.56%
BenchmarkMemmove16             18            7  -58.24%
BenchmarkMemmove32             18            8  -54.33%
BenchmarkMemmove64             18            8  -53.37%
BenchmarkMemmove128            20            9  -55.93%
BenchmarkMemmove256            25           11  -55.16%
BenchmarkMemmove512            33           33   -1.19%
BenchmarkMemmove1024           43           44   +2.06%
BenchmarkMemmove2048           61           61   +0.16%
BenchmarkMemmove4096           95           95   +0.00%

R=golang-dev, bradfitz, remyoudompheng, khr, iant, dominik.honnef
CC=golang-dev
https://golang.org/cl/9038048
2013-05-17 12:53:49 -07:00