The spec explains later in the "Operator precedence" section that *
has a higher precedence than +, but the current production rule
requires that "1 + 2 * 3" be parsed as "(1 + 2) * 3", instead of the
intended "1 + (2 * 3)".
The new production rule better matches cmd/internal/gc/go.y's grammar:
expr:
uexpr
| expr LOROR expr
| expr LANDAND expr
| ...
Fixes#10151.
Change-Id: I13c9635d6ddf1263cafe7cc63e68f3e5779e24ba
Reviewed-on: https://go-review.googlesource.com/9163
Reviewed-by: Robert Griesemer <gri@golang.org>
Set overflowing integer constants to 1 rather than 0 to avoid
spurious div-zero errors in subsequent constant expressions.
Also: Exclude new test case from go/types test since it's
running too long (go/types doesn't have an upper constant
size limit at the moment).
Fixes#7746.
Change-Id: I3768488ad9909a3cf995247b81ee78a8eb5a1e41
Reviewed-on: https://go-review.googlesource.com/9165
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
One important use case is a pipeline computation that pass values
from one Goroutine to the next and then exits or is placed in a
wait state. If GOMAXPROCS > 1 a Goroutine running on P1 will enable
another Goroutine and then immediately make P1 available to execute
it. We need to prevent other Ps from stealing the G that P1 is about
to execute. Otherwise the Gs can thrash between Ps causing unneeded
synchronization and slowing down throughput.
Fix this by changing the stealing logic so that when a P attempts to
steal the only G on some other P's run queue, it will pause
momentarily to allow the victim P to schedule the G.
As part of optimizing stealing we also use a per P victim queue
move stolen gs. This eliminates the zeroing of a stack local victim
queue which turned out to be expensive.
This CL is a necessary but not sufficient prerequisite to changing
the default value of GOMAXPROCS to something > 1 which is another
CL/discussion.
For highly serialized programs, such as GoroutineRing below this can
make a large difference. For larger and more parallel programs such
as the x/benchmarks there is no noticeable detriment.
~/work/code/src/rsc.io/benchstat/benchstat old.txt new.txt
name old mean new mean delta
GoroutineRing 30.2µs × (0.98,1.01) 30.1µs × (0.97,1.04) ~ (p=0.941)
GoroutineRing-2 113µs × (0.91,1.07) 30µs × (0.98,1.03) -73.17% (p=0.004)
GoroutineRing-4 144µs × (0.98,1.02) 32µs × (0.98,1.01) -77.69% (p=0.000)
GoroutineRingBuf 32.7µs × (0.97,1.03) 32.5µs × (0.97,1.02) ~ (p=0.795)
GoroutineRingBuf-2 120µs × (0.92,1.08) 33µs × (1.00,1.00) -72.48% (p=0.004)
GoroutineRingBuf-4 138µs × (0.92,1.06) 33µs × (1.00,1.00) -76.21% (p=0.003)
The bench benchmarks show little impact.
old new
garbage 7032879 7011696
httpold 25509 25301
splayold 1022073 1019499
jsonold 28230624 28081433
Change-Id: I228c48fed8d85c9bbef16a7edc53ab7898506f50
Reviewed-on: https://go-review.googlesource.com/9872
Reviewed-by: Austin Clements <austin@google.com>
FileConn and FilePacketConn APIs accept user-configured socket
descriptors to make them work together with runtime-integrated network
poller, but there's a limitation. The APIs reject protocol sockets that
are not supported by standard library. It's very hard for the net,
syscall packages to look after all platform, feature-specific sockets.
This change allows various platform, feature-specific socket descriptors
to use runtime-integrated network poller by using SocketConn,
SocketPacketConn APIs that bridge between the net, syscall packages and
platforms.
New exposed APIs:
pkg net, func SocketConn(*os.File, SocketAddr) (Conn, error)
pkg net, func SocketPacketConn(*os.File, SocketAddr) (PacketConn, error)
pkg net, type SocketAddr interface { Addr, Raw }
pkg net, type SocketAddr interface, Addr([]uint8) Addr
pkg net, type SocketAddr interface, Raw(Addr) []uint8
Fixes#10565.
Change-Id: Iec57499b3d84bb5cb0bcf3f664330c535eec11e3
Reviewed-on: https://go-review.googlesource.com/9275
Reviewed-by: Ian Lance Taylor <iant@golang.org>
If __LP64__ is defined then the type "long" is 64-bits, and there is
no need to explicitly request _FILE_OFFSET_BITS == 64. This changes
the definitions of F_GETLK, F_SETLK, and F_SETLKW on PPC to the values
that the kernel requires. The values used in C when _FILE_OFFSET_BITS
== 64 are corrected by the glibc fcntl function before making the
system call.
With this change, regenerate ppc64le files on Ubuntu trusty.
Change-Id: I8dddbd8a6bae877efff818f5c5dd06291ade3238
Reviewed-on: https://go-review.googlesource.com/9962
Reviewed-by: Minux Ma <minux@golang.org>
On android the generated header files are located in
pkg/$(go env GOOS)_$(go env GOARCH)_testcshared.
The test was broken since https://go-review.googlesource.com/9798.
The installation path differs based on codegenArgs
(around src/cmd/go/build.go line 389), and the codegenArgs
is platform dependent.
Change-Id: I01ae9cb957fb7676e399f3b8c067f24c5bd20b9d
Reviewed-on: https://go-review.googlesource.com/9980
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This will skip system call numbers that are ifdef'ed out in unistd.h,
as occurs on PPC.
Change-Id: I88e640e4621c7a8cc266433f34a7b4be71543ec9
Reviewed-on: https://go-review.googlesource.com/9966
Reviewed-by: Minux Ma <minux@golang.org>
Running these tests on the system stack is problematic because they
allocate Ps, which are large enough to overflow the system stack if
they are stack-allocated. It used to be necessary to run these tests
on the system stack because they were written in C, but since this is
no longer the case, we can fix this problem by simply not running the
tests on the system stack.
This also means we no longer need the hack in one of these tests that
forces the allocated Ps to escape to the heap, so eliminate that as
well.
Change-Id: I9064f5f8fd7f7b446ff39a22a70b172cfcb2dc57
Reviewed-on: https://go-review.googlesource.com/9923
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
The line in cgen.go was lost during the ginscmp CL.
The ggen.go change is not strictly necessary, but
it makes the 5g -S output for x[0] match what it said
before the ginscmp CL.
Change-Id: I5890a9ec1ac69a38509416eda5aea13b8b12b94a
Reviewed-on: https://go-review.googlesource.com/9929
Reviewed-by: Russ Cox <rsc@golang.org>
Fix bug on Linux SysProcAttr handling: setting both Pdeathsig and
Credential caused Pdeathsig to be ignored. This is because the kernel
clears the deathsignal field when performing a setuid/setgid
system call.
Avoid this by moving Pdeathsig handling after Credential handling.
Fixes#9686
Change-Id: Id01896ad4e979b8c448e0061f00aa8762ca0ac94
Reviewed-on: https://go-review.googlesource.com/3290
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The code generated for x = append(x, v) is roughly:
t := x
if len(t)+1 > cap(t) {
t = grow(t)
}
t[len(t)] = v
len(t)++
x = t
We used to generate this code as Go pseudocode during walk.
Generate it instead as actual instructions during gen.
Doing so lets us apply a few optimizations. The most important
is that when, as in the above example, the source slice and the
destination slice are the same, the code can instead do:
t := x
if len(t)+1 > cap(t) {
t = grow(t)
x = {base(t), len(t)+1, cap(t)}
} else {
len(x)++
}
t[len(t)] = v
That is, in the fast path that does not reallocate the array,
only the updated length needs to be written back to x,
not the array pointer and not the capacity. This is more like
what you'd write by hand in C. It's faster in general, since
the fast path elides two of the three stores, but it's especially
faster when the form of x is such that the base pointer write
would turn into a write barrier. No write, no barrier.
name old mean new mean delta
BinaryTree17 5.68s × (0.97,1.04) 5.81s × (0.98,1.03) +2.35% (p=0.023)
Fannkuch11 4.41s × (0.98,1.03) 4.35s × (1.00,1.00) ~ (p=0.090)
FmtFprintfEmpty 92.7ns × (0.91,1.16) 86.0ns × (0.94,1.11) -7.31% (p=0.038)
FmtFprintfString 281ns × (0.96,1.08) 276ns × (0.98,1.04) ~ (p=0.219)
FmtFprintfInt 288ns × (0.97,1.06) 274ns × (0.98,1.06) -4.94% (p=0.002)
FmtFprintfIntInt 493ns × (0.97,1.04) 506ns × (0.99,1.01) +2.65% (p=0.009)
FmtFprintfPrefixedInt 423ns × (0.97,1.04) 391ns × (0.99,1.01) -7.52% (p=0.000)
FmtFprintfFloat 598ns × (0.99,1.01) 566ns × (0.99,1.01) -5.27% (p=0.000)
FmtManyArgs 1.89µs × (0.98,1.05) 1.91µs × (0.99,1.01) ~ (p=0.231)
GobDecode 14.8ms × (0.98,1.03) 15.3ms × (0.99,1.02) +3.01% (p=0.000)
GobEncode 12.3ms × (0.98,1.01) 11.5ms × (0.97,1.03) -5.93% (p=0.000)
Gzip 656ms × (0.99,1.05) 645ms × (0.99,1.01) ~ (p=0.055)
Gunzip 142ms × (1.00,1.00) 142ms × (1.00,1.00) -0.32% (p=0.034)
HTTPClientServer 91.2µs × (0.97,1.04) 90.5µs × (0.97,1.04) ~ (p=0.468)
JSONEncode 32.6ms × (0.97,1.08) 32.0ms × (0.98,1.03) ~ (p=0.190)
JSONDecode 114ms × (0.97,1.05) 114ms × (0.99,1.01) ~ (p=0.887)
Mandelbrot200 6.11ms × (0.98,1.04) 6.04ms × (1.00,1.01) ~ (p=0.167)
GoParse 6.66ms × (0.97,1.04) 6.47ms × (0.97,1.05) -2.81% (p=0.014)
RegexpMatchEasy0_32 159ns × (0.99,1.00) 171ns × (0.93,1.07) +7.19% (p=0.002)
RegexpMatchEasy0_1K 538ns × (1.00,1.01) 550ns × (0.98,1.01) +2.30% (p=0.000)
RegexpMatchEasy1_32 138ns × (1.00,1.00) 135ns × (0.99,1.02) -1.60% (p=0.000)
RegexpMatchEasy1_1K 869ns × (0.99,1.01) 879ns × (1.00,1.01) +1.08% (p=0.000)
RegexpMatchMedium_32 252ns × (0.99,1.01) 243ns × (1.00,1.00) -3.71% (p=0.000)
RegexpMatchMedium_1K 72.7µs × (1.00,1.00) 70.3µs × (1.00,1.00) -3.34% (p=0.000)
RegexpMatchHard_32 3.85µs × (1.00,1.00) 3.82µs × (1.00,1.01) -0.81% (p=0.000)
RegexpMatchHard_1K 118µs × (1.00,1.00) 117µs × (1.00,1.00) -0.56% (p=0.000)
Revcomp 920ms × (0.97,1.07) 917ms × (0.97,1.04) ~ (p=0.808)
Template 129ms × (0.98,1.03) 114ms × (0.99,1.01) -12.06% (p=0.000)
TimeParse 619ns × (0.99,1.01) 622ns × (0.99,1.01) ~ (p=0.062)
TimeFormat 661ns × (0.98,1.04) 665ns × (0.99,1.01) ~ (p=0.524)
See next CL for combination with a similar optimization for slice.
The benchmarks that are slower in this CL are still faster overall
with the combination of the two.
Change-Id: I2a7421658091b2488c64741b4db15ab6c3b4cb7e
Reviewed-on: https://go-review.googlesource.com/9812
Reviewed-by: David Chase <drchase@google.com>
This lets us abstract away which arguments can be constants and so on
and lets the back ends reverse the order of arguments if that helps.
Change-Id: I283ec1d694f2dd84eba22e5eb4aad78a2d2d9eb0
Reviewed-on: https://go-review.googlesource.com/9810
Reviewed-by: David Chase <drchase@google.com>
Messages that are too big are rejected when read, so they should
be rejected when written too.
Fixes#10518.
Change-Id: I96678fbe2d94f51b957fe26faef33cd8df3823dd
Reviewed-on: https://go-review.googlesource.com/9965
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The status buffer built by the exit function
was not nil-terminated.
Fixes#10789.
Change-Id: I2d34ac50a19d138176c4b47393497ba7070d5b61
Reviewed-on: https://go-review.googlesource.com/9953
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Once added to the signal queue, the pointer passed to the
signal handler could no longer be valid. Instead of passing
the pointer to the note string, we recopy the value of the
note string to a static array in the signal queue.
Fixes#10784.
Change-Id: Iddd6837b58a14dfaa16b069308ae28a7b8e0965b
Reviewed-on: https://go-review.googlesource.com/9950
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Today's earlier fix can stay, but it's a band-aid over the real problem,
which is that bad code was slipping through the type checker
into the back end (and luckily causing a type error there).
I discovered this because my new append does not use the same
temporaries and failed the test as written.
Fixes#9521.
Change-Id: I7e33e2ea15743406e15c6f3fdf73e1edecda69bd
Reviewed-on: https://go-review.googlesource.com/9921
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Any Git branch can be the default branch not only master. Removing
hardwired 'checkout master', and using 'checkout {tag}' is the best
choice. It works with and without a master branch. Furthermore it
resolves the Github default branch issue. Changing Github default
branch is effectively changing HEAD.
Fixes#9032
Change-Id: I19a1221bcefe0806e7556c124c6da7ac0c2160b5
Reviewed-on: https://go-review.googlesource.com/5312
Reviewed-by: Russ Cox <rsc@golang.org>
registry.ReadSubKeyNames requires QUERY access right in addition to
ENUMERATE_SUB_KEYS.
This was making TestLocalZoneAbbr fail on Windows 7 in Paris/Madrid
timezone. It succeeded on Windows 8 because timezone name changed from
"Paris/Madrid" to "Romance Standard Time", the latter being matched by
an abbrs entry.
Change-Id: I791287ba9d1b3556246fa4e9e1604a1fbba1f5e6
Reviewed-on: https://go-review.googlesource.com/9809
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TestAcceptIgnoreSomeErrors was created to test that network
accept function ignores some errors. But conditions created
by the test also affects network reads. Change the test to
ignore these read errors when acceptable.
Fixes#10785
Change-Id: I3da85cb55bd3e78c1980ad949e53e82391f9b41e
Reviewed-on: https://go-review.googlesource.com/9942
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This:
1) Defines the ABI hash of a package (as the SHA1 of the __.PKGDEF)
2) Defines the ABI hash of a shared library (sort the packages by import
path, concatenate the hashes of the packages and SHA1 that)
3) When building a shared library, compute the above value and define a
global symbol that points to a go string that has the hash as its value.
4) When linking against a shared library, read the abi hash from the
library and put both the value seen at link time and a reference
to the global symbol into the moduledata.
5) During runtime initialization, check that the hash seen at link time
still matches the hash the global symbol points to.
Change-Id: Iaa54c783790e6dde3057a2feadc35473d49614a5
Reviewed-on: https://go-review.googlesource.com/8773
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
addmoduledata is called from a .init_array function and need to follow the
platform ABI. It contains accesses to global data which are rewritten to use
R15 by the assembler, and as R15 is callee-save we need to save it.
Change-Id: I03893efb1576aed4f102f2465421f256f3bb0f30
Reviewed-on: https://go-review.googlesource.com/9941
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I89778988baec1cf4a35d9342c7dbe8c4c08ff3cd
Reviewed-on: https://go-review.googlesource.com/9893
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Instead of errors like:
./blank2.go:15: cannot use ~b1 (type []int) as type int in assignment
we now have:
./blank2.go:15: cannot use _ (type []int) as type int in assignment
Less confusing for users.
Fixes#9521
Change-Id: Ieab9859040e8e0df95deeaee7eeb408d3be61c0f
Reviewed-on: https://go-review.googlesource.com/9902
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
DWARF generation appears to assume Cpos is cheap and this makes linking godoc
about 8% faster and linking the standard library into a single shared library
about 22% faster on my machine.
Updates #10571
Change-Id: I3f81efd0174e356716e7971c4f59810b72378177
Reviewed-on: https://go-review.googlesource.com/9913
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When running the client header timeout test, there is a race between
us timing out and waiting on the remaining requests to be serviced. If
the client times out before the server blocks on the channel in the
handler, we will be simultaneously adding to a waitgroup with the
value 0 and waiting on it when we call TestServer.Close().
This is largely a theoretical race. We have to time out before we
enter the handler and the only reason we would time out if we're
blocked on the channel. Nevertheless, make the race detector happy
by turning the close into a channel send. This turns the defer call
into a synchronization point and we can be sure that we've entered
the handler before we close the server.
Fixes#10780
Change-Id: Id73b017d1eb7503e446aa51538712ef49f2f5c9e
Reviewed-on: https://go-review.googlesource.com/9905
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The current implementation of typedmemmove walks the ptrmask
in the type to find out where pointers are. This led to turning off
GC programs for the Go 1.5 dev cycle, so that there would always
be a ptrmask. Instead of also interpreting the GC programs,
interpret the heap bitmap, which we know must be available and
up to date. (There is no point to write barriers when writing outside
the heap.)
This CL is only about correctness. The next CL will optimize the code.
Change-Id: Id1305c7c071fd2734ab96634b0e1c745b23fa793
Reviewed-on: https://go-review.googlesource.com/9886
Reviewed-by: Austin Clements <austin@google.com>
We want typedmemmove to use the heap bitmap to determine
where pointers are, instead of reinterpreting the type information.
The heap bitmap is simpler to access.
In general, typedmemmove will need to be able to look up the bits
for any word and find valid pointer information, so fill even after the
dead marker. Not filling after the dead marker was an optimization
I introduced only a few days ago, when reintroducing the dead marker
code. At the time I said it probably wouldn't last, and it didn't.
Change-Id: I6ba01bff17ddee1ff429f454abe29867ec60606e
Reviewed-on: https://go-review.googlesource.com/9885
Reviewed-by: Austin Clements <austin@google.com>
Moving them up makes them properly aligned on 32-bit systems.
There are some odd fields above them right now
(like fixalloc and mutex maybe).
Change-Id: I57851a5bbb2e7cc339712f004f99bb6c0cce0ca5
Reviewed-on: https://go-review.googlesource.com/9889
Reviewed-by: Austin Clements <austin@google.com>
Dead code.
This field is left over from Go 1.4, when we elided the fake write
barrier in this case. Today, it's unused (always false).
The upcoming append/slice changes handle this case again,
but without needing this field.
Change-Id: Ic6f160b64efdc1bbed02097ee03050f8cd0ab1b8
Reviewed-on: https://go-review.googlesource.com/9789
Reviewed-by: David Chase <drchase@google.com>
If you are using -h to get a stack trace at the site of the failure,
Yyerror will never return. Dump the register allocation sites
before calling Yyerror.
Change-Id: I51266c03e06cb5084c2eaa89b367b9ed85ba286a
Reviewed-on: https://go-review.googlesource.com/9788
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
The new(uint64) was moving to the stack, which may not be aligned.
Change-Id: Iad070964202001b52029494d43e299fed980f939
Reviewed-on: https://go-review.googlesource.com/9787
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: David Chase <drchase@google.com>
The -g mode is a debugging mode that prints instructions
as they are constructed. Gbranch was just missing the print.
Change-Id: I3fb45fd9bd3996ed96df5be903b9fd6bd97148b0
Reviewed-on: https://go-review.googlesource.com/9827
Reviewed-by: Rick Hudson <rlh@golang.org>
Reintroduce an optimization discarded during the initial conversion
from 4-bit heap bitmaps to 2-bit heap bitmaps: when we reach the
place in the bitmap where there are no more pointers, mark that position
for the GC so that it can avoid scanning past that place.
During heapBitsSetType we can also avoid initializing heap bitmap
beyond that location, which gives a bit of a win compared to Go 1.4.
This particular optimization (not initializing the heap bitmap) may not last:
we might change typedmemmove to use the heap bitmap, in which
case it would all need to be initialized. The early stop in the GC scan
will stay no matter what.
Compared to Go 1.4 (github.com/rsc/go, branch go14bench):
name old mean new mean delta
SetTypeNode64 80.7ns × (1.00,1.01) 57.4ns × (1.00,1.01) -28.83% (p=0.000)
SetTypeNode64Dead 80.5ns × (1.00,1.01) 13.1ns × (0.99,1.02) -83.77% (p=0.000)
SetTypeNode64Slice 2.16µs × (1.00,1.01) 1.54µs × (1.00,1.01) -28.75% (p=0.000)
SetTypeNode64DeadSlice 2.16µs × (1.00,1.01) 1.52µs × (1.00,1.00) -29.74% (p=0.000)
Compared to previous CL:
name old mean new mean delta
SetTypeNode64 56.7ns × (1.00,1.00) 57.4ns × (1.00,1.01) +1.19% (p=0.000)
SetTypeNode64Dead 57.2ns × (1.00,1.00) 13.1ns × (0.99,1.02) -77.15% (p=0.000)
SetTypeNode64Slice 1.56µs × (1.00,1.01) 1.54µs × (1.00,1.01) -0.89% (p=0.000)
SetTypeNode64DeadSlice 1.55µs × (1.00,1.01) 1.52µs × (1.00,1.00) -2.23% (p=0.000)
This is the last CL in the sequence converting from the 4-bit heap
to the 2-bit heap, with all the same optimizations reenabled.
Compared to before that process began (compared to CL 9701 patch set 1):
name old mean new mean delta
BinaryTree17 5.87s × (0.94,1.09) 5.91s × (0.96,1.06) ~ (p=0.578)
Fannkuch11 4.32s × (1.00,1.00) 4.32s × (1.00,1.00) ~ (p=0.474)
FmtFprintfEmpty 89.1ns × (0.95,1.16) 89.0ns × (0.93,1.10) ~ (p=0.942)
FmtFprintfString 283ns × (0.98,1.02) 298ns × (0.98,1.06) +5.33% (p=0.000)
FmtFprintfInt 284ns × (0.98,1.04) 286ns × (0.98,1.03) ~ (p=0.208)
FmtFprintfIntInt 486ns × (0.98,1.03) 498ns × (0.97,1.06) +2.48% (p=0.000)
FmtFprintfPrefixedInt 400ns × (0.99,1.02) 408ns × (0.98,1.02) +2.23% (p=0.000)
FmtFprintfFloat 566ns × (0.99,1.01) 587ns × (0.98,1.01) +3.69% (p=0.000)
FmtManyArgs 1.91µs × (0.99,1.02) 1.94µs × (0.99,1.02) +1.81% (p=0.000)
GobDecode 15.5ms × (0.98,1.05) 15.8ms × (0.98,1.03) +1.94% (p=0.002)
GobEncode 11.9ms × (0.97,1.03) 12.0ms × (0.96,1.09) ~ (p=0.263)
Gzip 648ms × (0.99,1.01) 648ms × (0.99,1.01) ~ (p=0.992)
Gunzip 143ms × (1.00,1.00) 143ms × (1.00,1.01) ~ (p=0.585)
HTTPClientServer 89.2µs × (0.99,1.02) 90.3µs × (0.98,1.01) +1.24% (p=0.000)
JSONEncode 32.3ms × (0.97,1.06) 31.6ms × (0.99,1.01) -2.29% (p=0.000)
JSONDecode 106ms × (0.99,1.01) 107ms × (1.00,1.01) +0.62% (p=0.000)
Mandelbrot200 6.02ms × (1.00,1.00) 6.03ms × (1.00,1.01) ~ (p=0.250)
GoParse 6.57ms × (0.97,1.06) 6.53ms × (0.99,1.03) ~ (p=0.243)
RegexpMatchEasy0_32 162ns × (1.00,1.00) 161ns × (1.00,1.01) -0.80% (p=0.000)
RegexpMatchEasy0_1K 561ns × (0.99,1.02) 541ns × (0.99,1.01) -3.67% (p=0.000)
RegexpMatchEasy1_32 145ns × (0.95,1.04) 138ns × (1.00,1.00) -5.04% (p=0.000)
RegexpMatchEasy1_1K 864ns × (0.99,1.04) 887ns × (0.99,1.01) +2.57% (p=0.000)
RegexpMatchMedium_32 255ns × (0.99,1.04) 253ns × (0.99,1.01) -1.05% (p=0.012)
RegexpMatchMedium_1K 73.9µs × (0.98,1.04) 72.8µs × (1.00,1.00) -1.51% (p=0.005)
RegexpMatchHard_32 3.92µs × (0.98,1.04) 3.85µs × (1.00,1.01) -1.88% (p=0.002)
RegexpMatchHard_1K 120µs × (0.98,1.04) 117µs × (1.00,1.01) -2.02% (p=0.001)
Revcomp 936ms × (0.95,1.08) 922ms × (0.97,1.08) ~ (p=0.234)
Template 130ms × (0.98,1.04) 126ms × (0.99,1.01) -2.99% (p=0.000)
TimeParse 638ns × (0.98,1.05) 628ns × (0.99,1.01) -1.54% (p=0.004)
TimeFormat 674ns × (0.99,1.01) 668ns × (0.99,1.01) -0.80% (p=0.001)
The slowdown of the first few benchmarks seems to be due to the new
atomic operations for certain small size allocations. But the larger
benchmarks mostly improve, probably due to the decreased memory
pressure from having half as much heap bitmap.
CL 9706, which removes the (never used anymore) wbshadow mode,
gets back what is lost in the early microbenchmarks.
Change-Id: I37423a209e8ec2a2e92538b45cac5422a6acd32d
Reviewed-on: https://go-review.googlesource.com/9705
Reviewed-by: Rick Hudson <rlh@golang.org>
For the conversion of the heap bitmap from 4-bit to 2-bit fields,
I replaced heapBitsSetType with the dumbest thing that could possibly work:
two atomic operations (atomicand8+atomicor8) per 2-bit field.
This CL replaces that code with a proper implementation that
avoids the atomics whenever possible. Benchmarks vs base CL
(before the conversion to 2-bit heap bitmap) and vs Go 1.4 below.
Compared to Go 1.4, SetTypePtr (a 1-pointer allocation)
is 10ns slower because a race against the concurrent GC requires the
use of an atomicor8 that used to be an ordinary write. This slowdown
was present even in the base CL.
Compared to both Go 1.4 and base, SetTypeNode8 (a 10-word allocation)
is 10ns slower because it too needs a new atomic, because with the
denser representation, the byte on the end of the allocation is now shared
with the object next to it; this was not true with the 4-bit representation.
Excluding these two (fundamental) slowdowns due to the use of atomics,
the new code is noticeably faster than both Go 1.4 and the base CL.
The next CL will reintroduce the ``typeDead'' optimization.
Stats are from 5 runs on a MacBookPro10,2 (late 2012 Core i5).
Compared to base CL (** = new atomic)
name old mean new mean delta
SetTypePtr 14.1ns × (0.99,1.02) 14.7ns × (0.93,1.10) ~ (p=0.175)
SetTypePtr8 18.4ns × (1.00,1.01) 18.6ns × (0.81,1.21) ~ (p=0.866)
SetTypePtr16 28.7ns × (1.00,1.00) 22.4ns × (0.90,1.27) -21.88% (p=0.015)
SetTypePtr32 52.3ns × (1.00,1.00) 33.8ns × (0.93,1.24) -35.37% (p=0.001)
SetTypePtr64 79.2ns × (1.00,1.00) 55.1ns × (1.00,1.01) -30.43% (p=0.000)
SetTypePtr126 118ns × (1.00,1.00) 100ns × (1.00,1.00) -15.97% (p=0.000)
SetTypePtr128 130ns × (0.92,1.19) 98ns × (1.00,1.00) -24.36% (p=0.008)
SetTypePtrSlice 726ns × (0.96,1.08) 760ns × (1.00,1.00) ~ (p=0.152)
SetTypeNode1 14.1ns × (0.94,1.15) 12.0ns × (1.00,1.01) -14.60% (p=0.020)
SetTypeNode1Slice 135ns × (0.96,1.07) 88ns × (1.00,1.00) -34.53% (p=0.000)
SetTypeNode8 20.9ns × (1.00,1.01) 32.6ns × (1.00,1.00) +55.37% (p=0.000) **
SetTypeNode8Slice 414ns × (0.99,1.02) 244ns × (1.00,1.00) -41.09% (p=0.000)
SetTypeNode64 80.0ns × (1.00,1.00) 57.4ns × (1.00,1.00) -28.23% (p=0.000)
SetTypeNode64Slice 2.15µs × (1.00,1.01) 1.56µs × (1.00,1.00) -27.43% (p=0.000)
SetTypeNode124 119ns × (0.99,1.00) 100ns × (1.00,1.00) -16.11% (p=0.000)
SetTypeNode124Slice 3.40µs × (1.00,1.00) 2.93µs × (1.00,1.00) -13.80% (p=0.000)
SetTypeNode126 120ns × (1.00,1.01) 98ns × (1.00,1.00) -18.19% (p=0.000)
SetTypeNode126Slice 3.53µs × (0.98,1.08) 3.02µs × (1.00,1.00) -14.49% (p=0.002)
SetTypeNode1024 726ns × (0.97,1.09) 740ns × (1.00,1.00) ~ (p=0.451)
SetTypeNode1024Slice 24.9µs × (0.89,1.37) 23.1µs × (1.00,1.00) ~ (p=0.476)
Compared to Go 1.4 (** = new atomic)
name old mean new mean delta
SetTypePtr 5.71ns × (0.89,1.19) 14.68ns × (0.93,1.10) +157.24% (p=0.000) **
SetTypePtr8 19.3ns × (0.96,1.10) 18.6ns × (0.81,1.21) ~ (p=0.638)
SetTypePtr16 30.7ns × (0.99,1.03) 22.4ns × (0.90,1.27) -26.88% (p=0.005)
SetTypePtr32 51.5ns × (1.00,1.00) 33.8ns × (0.93,1.24) -34.40% (p=0.001)
SetTypePtr64 83.6ns × (0.94,1.12) 55.1ns × (1.00,1.01) -34.12% (p=0.001)
SetTypePtr126 137ns × (0.87,1.26) 100ns × (1.00,1.00) -27.10% (p=0.028)
SetTypePtrSlice 865ns × (0.80,1.23) 760ns × (1.00,1.00) ~ (p=0.243)
SetTypeNode1 15.2ns × (0.88,1.12) 12.0ns × (1.00,1.01) -20.89% (p=0.014)
SetTypeNode1Slice 156ns × (0.93,1.16) 88ns × (1.00,1.00) -43.57% (p=0.001)
SetTypeNode8 23.8ns × (0.90,1.18) 32.6ns × (1.00,1.00) +36.76% (p=0.003) **
SetTypeNode8Slice 502ns × (0.92,1.10) 244ns × (1.00,1.00) -51.46% (p=0.000)
SetTypeNode64 85.6ns × (0.94,1.11) 57.4ns × (1.00,1.00) -32.89% (p=0.001)
SetTypeNode64Slice 2.36µs × (0.91,1.14) 1.56µs × (1.00,1.00) -33.96% (p=0.002)
SetTypeNode124 130ns × (0.91,1.12) 100ns × (1.00,1.00) -23.49% (p=0.004)
SetTypeNode124Slice 3.81µs × (0.90,1.22) 2.93µs × (1.00,1.00) -23.09% (p=0.025)
There are fewer benchmarks vs Go 1.4 because unrolling directly
into the heap bitmap is not yet implemented, so those would not
be meaningful comparisons.
These benchmarks were not present in Go 1.4 as distributed.
The backport to Go 1.4 is in github.com/rsc/go's go14bench branch,
commit 71d5ee5.
Change-Id: I95ed05a22bf484b0fc9efad549279e766c98d2b6
Reviewed-on: https://go-review.googlesource.com/9704
Reviewed-by: Rick Hudson <rlh@golang.org>
Previous CLs changed the representation of the non-heap type bitmaps
to be 1-bit bitmaps (pointer or not). Before this CL, the heap bitmap
stored a 2-bit type for each word and a mark bit and checkmark bit
for the first word of the object. (There used to be additional per-word bits.)
Reduce heap bitmap to 2-bit, with 1 dedicated to pointer or not,
and the other used for mark, checkmark, and "keep scanning forward
to find pointers in this object." See comments for details.
This CL replaces heapBitsSetType with very slow but obviously correct code.
A followup CL will optimize it. (Spoiler: the new code is faster than Go 1.4 was.)
Change-Id: I999577a133f3cfecacebdec9cdc3573c235c7fb9
Reviewed-on: https://go-review.googlesource.com/9703
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
The type information in reflect.Type and the GC programs is now
1 bit per word, down from 2 bits.
The in-memory unrolled type bitmap representation are now
1 bit per word, down from 4 bits.
The conversion from the unrolled (now 1-bit) bitmap to the
heap bitmap (still 4-bit) is not optimized. A followup CL will
work on that, after the heap bitmap has been converted to 2-bit.
The typeDead optimization, in which a special value denotes
that there are no more pointers anywhere in the object, is lost
in this CL. A followup CL will bring it back in the final form of
heapBitsSetType.
Change-Id: If61e67950c16a293b0b516a6fd9a1c755b6d5549
Reviewed-on: https://go-review.googlesource.com/9702
Reviewed-by: Austin Clements <austin@google.com>
There was an old benchmark that measured this indirectly
via allocation, but I don't understand how to factor out the
allocation cost when interpreting the numbers.
Replace with a benchmark that only calls heapBitsSetType,
that does not allocate. This was not possible when the
benchmark was first written, because heapBitsSetType had
not been factored out of mallocgc.
Change-Id: I30f0f02362efab3465a50769398be859832e6640
Reviewed-on: https://go-review.googlesource.com/9701
Reviewed-by: Austin Clements <austin@google.com>
