Currently we always create context objects for closures that capture variables.
However, it is completely unnecessary for direct calls of closures
(whether it is func()(), defer func()() or go func()()).
This change transforms any OCALLFUNC(OCLOSURE) to normal function call.
Closed variables become function arguments.
This transformation is especially beneficial for go func(),
because we do not need to allocate context object on heap.
But it makes direct closure calls a bit faster as well (see BenchmarkClosureCall).
On implementation level it required to introduce yet another compiler pass.
However, the pass iterates only over xtop, so it should not be an issue.
Transformation consists of two parts: closure transformation and call site
transformation. We can't run these parts on different sides of escape analysis,
because tree state is inconsistent. We can do both parts during typecheck,
we don't know how to capture variables and don't have call site.
We can't do both parts during walk of OCALLFUNC, because we can walk
OCLOSURE body earlier.
So now capturevars pass only decides how to capture variables
(this info is required for escape analysis). New transformclosure
pass, that runs just before order/walk, does all transformations
of a closure. And later walk of OCALLFUNC(OCLOSURE) transforms call site.
benchmark old ns/op new ns/op delta
BenchmarkClosureCall 4.89 3.09 -36.81%
BenchmarkCreateGoroutinesCapture 1634 1294 -20.81%
benchmark old allocs new allocs delta
BenchmarkCreateGoroutinesCapture 6 2 -66.67%
benchmark old bytes new bytes delta
BenchmarkCreateGoroutinesCapture 176 48 -72.73%
Change-Id: Ic85e1706e18c3235cc45b3c0c031a9c1cdb7a40e
Reviewed-on: https://go-review.googlesource.com/4050
Reviewed-by: Russ Cox <rsc@golang.org>
Consider an interface value i of type I and concrete value c of type C.
Prior to this CL, i==c was evaluated as
I(c) == i
Evaluating I(c) can allocate.
This CL changes the evaluation of i==c to
x, ok := i.(C); ok && x == c
The new generated code is shorter and does not allocate directly.
If C is small, as it is in every instance in the stdlib,
the new code also uses less stack space
and makes one runtime call instead of two.
If C is very large, the original implementation is used.
The cutoff for "very large" is 1<<16,
following the stack vs heap cutoff used elsewhere.
This kind of comparison occurs in 38 places in the stdlib,
mostly in the net and os packages.
benchmark old ns/op new ns/op delta
BenchmarkEqEfaceConcrete 29.5 7.92 -73.15%
BenchmarkEqIfaceConcrete 32.1 7.90 -75.39%
BenchmarkNeEfaceConcrete 29.9 7.90 -73.58%
BenchmarkNeIfaceConcrete 35.9 7.90 -77.99%
Fixes#9370.
Change-Id: I7c4555950bcd6406ee5c613be1f2128da2c9a2b7
Reviewed-on: https://go-review.googlesource.com/2096
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Support the following conversions in escape analysis:
[]rune("foo")
[]byte("foo")
string([]rune{})
If the result does not escape, allocate temp buffer on stack
and pass it to runtime functions.
Change-Id: I1d075907eab8b0109ad7ad1878104b02b3d5c690
Reviewed-on: https://go-review.googlesource.com/3590
Reviewed-by: Russ Cox <rsc@golang.org>
Ordinary switch statements are rewritten
into a sequence of if statements.
Staticly dead cases were not being eliminated
because the rewrite introduced a temporary,
which hid the fact that the case was a constant.
Stop doing that.
This eliminates dead code in the standard library at:
runtime/cgocall.go:219
runtime/cgocall.go:269
debug/gosym/pclntab.go:175
debug/macho/file.go:208
math/big/nat.go:635
math/big/nat.go:850
math/big/nat.go:1058
cmd/pprof/internal/commands/commands.go:86
net/sock_bsd.go:19
cmd/go/build.go:2657
cmd/go/env.go:90
Fixes#9608.
Change-Id: Ic23a05dfbb1ad91d5f62a6506b35a13e51b33e38
Reviewed-on: https://go-review.googlesource.com/3980
Reviewed-by: Keith Randall <khr@golang.org>
Only documentation / comment changes. Update references to
point to golang.org permalinks or go.googlesource.com/go.
References in historical release notes under doc are left as is.
Change-Id: Icfc14e4998723e2c2d48f9877a91c5abef6794ea
Reviewed-on: https://go-review.googlesource.com/4060
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The main issue is that the misc/cgo/{stdio,life} tests are silently
getting skipped when invoked from run.bash.
run.go should ignore any build tags after the first blank line in
source file. It already checks for test actions only upto the first
blank line. Build tags must be specified in the same block.
See http://golang.org/cl/3675 for background.
Change-Id: Id8abf000119e3335f7250d8ef34aac7811fc9dff
Reviewed-on: https://go-review.googlesource.com/3812
Reviewed-by: Minux Ma <minux@golang.org>
issue9355 generated a file a.[568] in test/ directory and left it there.
For tests like these, it is best to chdir to a test specific directory
before generating any temporary files, since the tests are running
in parallel and might otherwise race with each other for the same files.
Change-Id: I58d96256d4d8ee3fda70d81077f19006064a7425
Reviewed-on: https://go-review.googlesource.com/3813
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Kindly detected by race builders by failing TestRaceRange.
ORANGE typecheck does not increment decldepth around body.
Change-Id: I0df5f310cb3370a904c94d9647a9cf0f15729075
Reviewed-on: https://go-review.googlesource.com/3507
Reviewed-by: Russ Cox <rsc@golang.org>
Type switch variables was not typechecked.
Previously it lead only to a minor consequence:
switch unsafe.Sizeof = x.(type) {
generated an inconsistent error message.
But capturing by value functionality now requries typechecking of all ONAMEs.
Fixes#9731
Change-Id: If037883cba53d85028fb97b1328696091b3b7ddd
Reviewed-on: https://go-review.googlesource.com/3600
Reviewed-by: Russ Cox <rsc@golang.org>
This adds a "framepointer" GOEXPERIMENT that that makes the amd64
toolchain maintain base pointer chains in the same way that gcc
-fno-omit-frame-pointer does. Go doesn't use these saved base
pointers, but this does enable external tools like Linux perf and
VTune to unwind Go stacks when collecting system-wide profiles.
This requires support in the compilers to not clobber BP, support in
liblink for generating the BP-saving function prologue and unwinding
epilogue, and support in the runtime to save BPs across preemption, to
skip saved BPs during stack unwinding and, and to adjust saved BPs
during stack moving.
As with other GOEXPERIMENTs, everything from the toolchain to the
runtime must be compiled with this experiment enabled. To do this,
run make.bash (or all.bash) with GOEXPERIMENT=framepointer.
Change-Id: I4024853beefb9539949e5ca381adfdd9cfada544
Reviewed-on: https://go-review.googlesource.com/2992
Reviewed-by: Russ Cox <rsc@golang.org>
cmd/go doesn't complain (this is an open issue), but go/types does
Change-Id: I2caec1f7aec991a9500d2c3504c29e4ab718c138
Reviewed-on: https://go-review.googlesource.com/3541
Reviewed-by: Alan Donovan <adonovan@google.com>
Language specification says that variables are captured by reference.
And that is what gc compiler does. However, in lots of cases it is
possible to capture variables by value under the hood without
affecting visible behavior of programs. For example, consider
the following typical pattern:
func (o *Obj) requestMany(urls []string) []Result {
wg := new(sync.WaitGroup)
wg.Add(len(urls))
res := make([]Result, len(urls))
for i := range urls {
i := i
go func() {
res[i] = o.requestOne(urls[i])
wg.Done()
}()
}
wg.Wait()
return res
}
Currently o, wg, res, and i are captured by reference causing 3+len(urls)
allocations (e.g. PPARAM o is promoted to PPARAMREF and moved to heap).
But all of them can be captured by value without changing behavior.
This change implements simple strategy for capturing by value:
if a captured variable is not addrtaken and never assigned to,
then it is captured by value (it is effectively const).
This simple strategy turned out to be very effective:
~80% of all captures in std lib are turned into value captures.
The remaining 20% are mostly in defers and non-escaping closures,
that is, they do not cause allocations anyway.
benchmark old allocs new allocs delta
BenchmarkCompressedZipGarbage 153 126 -17.65%
BenchmarkEncodeDigitsSpeed1e4 91 69 -24.18%
BenchmarkEncodeDigitsSpeed1e5 178 129 -27.53%
BenchmarkEncodeDigitsSpeed1e6 1510 1051 -30.40%
BenchmarkEncodeDigitsDefault1e4 100 75 -25.00%
BenchmarkEncodeDigitsDefault1e5 193 139 -27.98%
BenchmarkEncodeDigitsDefault1e6 1420 985 -30.63%
BenchmarkEncodeDigitsCompress1e4 100 75 -25.00%
BenchmarkEncodeDigitsCompress1e5 193 139 -27.98%
BenchmarkEncodeDigitsCompress1e6 1420 985 -30.63%
BenchmarkEncodeTwainSpeed1e4 109 81 -25.69%
BenchmarkEncodeTwainSpeed1e5 211 151 -28.44%
BenchmarkEncodeTwainSpeed1e6 1588 1097 -30.92%
BenchmarkEncodeTwainDefault1e4 103 77 -25.24%
BenchmarkEncodeTwainDefault1e5 199 143 -28.14%
BenchmarkEncodeTwainDefault1e6 1324 917 -30.74%
BenchmarkEncodeTwainCompress1e4 103 77 -25.24%
BenchmarkEncodeTwainCompress1e5 190 137 -27.89%
BenchmarkEncodeTwainCompress1e6 1327 919 -30.75%
BenchmarkConcurrentDBExec 16223 16220 -0.02%
BenchmarkConcurrentStmtQuery 17687 16182 -8.51%
BenchmarkConcurrentStmtExec 5191 5186 -0.10%
BenchmarkConcurrentTxQuery 17665 17661 -0.02%
BenchmarkConcurrentTxExec 15154 15150 -0.03%
BenchmarkConcurrentTxStmtQuery 17661 16157 -8.52%
BenchmarkConcurrentTxStmtExec 3677 3673 -0.11%
BenchmarkConcurrentRandom 14000 13614 -2.76%
BenchmarkManyConcurrentQueries 25 22 -12.00%
BenchmarkDecodeComplex128Slice 318 252 -20.75%
BenchmarkDecodeFloat64Slice 318 252 -20.75%
BenchmarkDecodeInt32Slice 318 252 -20.75%
BenchmarkDecodeStringSlice 2318 2252 -2.85%
BenchmarkDecode 11 8 -27.27%
BenchmarkEncodeGray 64 56 -12.50%
BenchmarkEncodeNRGBOpaque 64 56 -12.50%
BenchmarkEncodeNRGBA 67 58 -13.43%
BenchmarkEncodePaletted 68 60 -11.76%
BenchmarkEncodeRGBOpaque 64 56 -12.50%
BenchmarkGoLookupIP 153 139 -9.15%
BenchmarkGoLookupIPNoSuchHost 508 466 -8.27%
BenchmarkGoLookupIPWithBrokenNameServer 245 226 -7.76%
BenchmarkClientServer 62 59 -4.84%
BenchmarkClientServerParallel4 62 59 -4.84%
BenchmarkClientServerParallel64 62 59 -4.84%
BenchmarkClientServerParallelTLS4 79 76 -3.80%
BenchmarkClientServerParallelTLS64 112 109 -2.68%
BenchmarkCreateGoroutinesCapture 10 6 -40.00%
BenchmarkAfterFunc 1006 1005 -0.10%
Fixes#6632.
Change-Id: I0cd51e4d356331d7f3c5f447669080cd19b0d2ca
Reviewed-on: https://go-review.googlesource.com/3166
Reviewed-by: Russ Cox <rsc@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>
Escape analysis treats everything assigned to OIND/ODOTPTR as escaping.
As the result b escapes in the following code:
func (b *Buffer) Foo() {
n, m := ...
b.buf = b.buf[n:m]
}
This change recognizes such assignments and ignores them.
Update issue #9043.
Update issue #7921.
There are two similar cases in std lib that benefit from this optimization.
First is in archive/zip:
type readBuf []byte
func (b *readBuf) uint32() uint32 {
v := binary.LittleEndian.Uint32(*b)
*b = (*b)[4:]
return v
}
Second is in time:
type data struct {
p []byte
error bool
}
func (d *data) read(n int) []byte {
if len(d.p) < n {
d.p = nil
d.error = true
return nil
}
p := d.p[0:n]
d.p = d.p[n:]
return p
}
benchmark old ns/op new ns/op delta
BenchmarkCompressedZipGarbage 32431724 32217851 -0.66%
benchmark old allocs new allocs delta
BenchmarkCompressedZipGarbage 153 143 -6.54%
Change-Id: Ia6cd32744e02e36d6d8c19f402f8451101711626
Reviewed-on: https://go-review.googlesource.com/3162
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Currently all PTRLIT element initializers escape. There is no reason for that.
This change links STRUCTLIT to PTRLIT; STRUCTLIT element initializers are
already linked to the STRUCTLIT. As the result, PTRLIT element initializers
escape when PTRLIT itself escapes.
Change-Id: I89ecd8677cbf81addcfd469cd2fd461c0e9bf7dd
Reviewed-on: https://go-review.googlesource.com/3031
Reviewed-by: Russ Cox <rsc@golang.org>
The compiler has a phase ordering problem. Escape analysis runs
before wrapper generation. When a generated wrapper calls a method
defined in a different package, if that call is inlined, there will be
no escape information for the variables defined in the inlined call.
Those variables will be placed on the stack, which fails if they
actually do escape.
There are probably various complex ways to fix this. This is a simple
way to avoid it: when a generated wrapper calls a method defined in a
different package, treat all local variables as escaping.
Fixes#9537.
Change-Id: I530f39346de16ad173371c6c3f69cc189351a4e9
Reviewed-on: https://go-review.googlesource.com/3092
Reviewed-by: Russ Cox <rsc@golang.org>
We were failing ^uint16(0xffff) == 0, as we computed 0xffff0000 instead.
I could only trigger a failure for the above case, the other two tests
^uint16(0xfffe) == 1 and -uint16(0xffff) == 1 didn't seem to fail
previously. Somehow they get MOVHUs inserted for other reasons (used
by CMP instead of TST?). I fixed OMINUS anyway, better safe than
sorry.
Fixes#9604
Change-Id: I4c2d5bdc667742873ac029fdbe3db0cf12893c27
Reviewed-on: https://go-review.googlesource.com/2940
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
The various files are confusingly named and their operation
not easy to see. Add a comment to cmplxdivide.c, one of the few
C files that will endure in the repository, to explain how to build
and run the test.
Change-Id: I1fd5c564a14217e1b9815b09bc24cc43c54c096f
Reviewed-on: https://go-review.googlesource.com/2850
Reviewed-by: Russ Cox <rsc@golang.org>
Recognize loops of the form
for i := range a {
a[i] = zero
}
in which the evaluation of a is free from side effects.
Replace these loops with calls to memclr.
This occurs in the stdlib in 18 places.
The motivating example is clearing a byte slice:
benchmark old ns/op new ns/op delta
BenchmarkGoMemclr5 3.31 3.26 -1.51%
BenchmarkGoMemclr16 13.7 3.28 -76.06%
BenchmarkGoMemclr64 50.8 4.14 -91.85%
BenchmarkGoMemclr256 157 6.02 -96.17%
Update #5373.
Change-Id: I99d3e6f5f268e8c6499b7e661df46403e5eb83e4
Reviewed-on: https://go-review.googlesource.com/2520
Reviewed-by: Keith Randall <khr@golang.org>
run GC in its own background goroutine making the
caller runnable if resources are available. This is
critical in single goroutine applications.
Allow goroutines that allocate a lot to help out
the GC and in doing so throttle their own allocation.
Adjust test so that it only detects that a GC is run
during init calls and not whether the GC is memory
efficient. Memory efficiency work will happen later
in 1.5.
Change-Id: I4306f5e377bb47c69bda1aedba66164f12b20c2b
Reviewed-on: https://go-review.googlesource.com/2349
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This test was taking a long time, reduce its zealousness.
Change-Id: Ib824247b84b0039a9ec690f72336bef3738d4c44
Reviewed-on: https://go-review.googlesource.com/2502
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Minux Ma <minux@golang.org>
The compiler converts 'val, ok = m[key]' to
tmp, ok = <runtime call>
val = *tmp
For lookups of the form '_, ok = m[key]',
the second statement is unnecessary.
By not generating it we save a nil check.
Change-Id: I21346cc195cb3c62e041af8b18770c0940358695
Reviewed-on: https://go-review.googlesource.com/1975
Reviewed-by: Russ Cox <rsc@golang.org>
If the user provided a key but no value via -ldflag -X,
another linker flag was used as the value.
Placing the user's flags at the end avoids this problem.
It also provides the user the opportunity to
override existing linker flags.
Fixes#8810.
Change-Id: I96f4190713dc9a9c29142e56658446fba7fb6bc8
Reviewed-on: https://go-review.googlesource.com/2242
Reviewed-by: Minux Ma <minux@golang.org>
These tests were enabled as part of change 1774.
They depend on the errchk tool, which is a Perl
script. However, Perl is not available on Plan 9.
Change-Id: I82707aae16013acc9a3800d39b0084588b852b53
Reviewed-on: https://go-review.googlesource.com/2031
Reviewed-by: Minux Ma <minux@golang.org>
Broken by e7173dfdfd
Fix by simply disabling the relevant tests.
* bug248 and bug345 require errchk, but we can't
rely on perl being available.
* bug369 is disabled anyway.
Change-Id: Idf73ebccb066943e3fe17c2f662b37238ec74dfe
Reviewed-on: https://go-review.googlesource.com/2052
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Gccgo creates a struct to hold the arguments for the deferred
function. In this example the struct holds a type defined in a
different package. The bug was that gccgo tried to create an equality
function for this struct, and it implemented that function by calling
the equality function for the type defined in the other package.
Since that type is not exported, the reference to the equality
function failed at link time. Normally it is impossible for a struct
to directly contain a member that is an unexported type from another
package, but in this specific case it was possible. Fixed in gccgo
with https://codereview.appspot.com/183500043 .
Change-Id: I8ec3a33631225b9ac2a4ac060cb4d10b4635e60b
Reviewed-on: https://go-review.googlesource.com/1690
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
* bug248, bug345, bug369, and bug429 were ported from bash commands to run scripts. bug369 remains disabled.
* bug395 is a test for issue 1909, which is still open. It is marked as skip now and will be usable with compile with run.go when issue 1909 is fixed.
Fixes#4139
Updates #1909
Change-Id: Ibb5fbfb5cf72ddc285829245318eeacd3fb5a636
Reviewed-on: https://go-review.googlesource.com/1774
Reviewed-by: Russ Cox <rsc@golang.org>
When we do y = &x for global variables x and y, y gets initialized
at link time. Do the same for y = &x.f if x is a struct and y=&x[5]
if x is an array.
fixes#9217fixes#9355
Change-Id: Iea3c0ce2ce1b309e2b760e345608fd95460b5713
Reviewed-on: https://go-review.googlesource.com/1691
Reviewed-by: Minux Ma <minux@golang.org>
This test was added in CL 151000043.
It got lost in CL 144630044.
Change-Id: I318ab11be8e3e7489fc1395457c029c8bdb2aa41
Reviewed-on: https://go-review.googlesource.com/1773
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Gccgo incorrectly executed functions multiple times when they appeared
in a composite literal that required a conversion between different
interface types.
Change-Id: I7b40e76ed23fa8440ffa03b262041265c109adf7
Reviewed-on: https://go-review.googlesource.com/1710
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Gccgo failed to create the type descriptor for the type used to
allocate the nil value passed to append as the second argument when
append is called with only one argument. Calling append with only one
argument is unusual but obviously should not cause a compiler crash.
Change-Id: I530821847dfd68f0302de6ca6a84dfbc79653935
Reviewed-on: https://go-review.googlesource.com/1692
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
It shouldn't semacquire() inside an acquirem(), the runtime
thinks that means deadlock. It actually isn't a deadlock, but it
looks like it because acquirem() does m.locks++.
Candidate for inclusion in 1.4.1. runtime.Stack with all=true
is pretty unuseable in GOMAXPROCS>1 environment.
fixes#9321
Change-Id: Iac6b664217d24763b9878c20e49229a1ecffc805
Reviewed-on: https://go-review.googlesource.com/1600
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Make sure dequeueing from a channel queue does not exhibit quadratic time behavior.
Change-Id: Ifb7c709b026f74c7e783610d4914dd92909a441b
Reviewed-on: https://go-review.googlesource.com/1212
Reviewed-by: Russ Cox <rsc@golang.org>
Usage:
fibo <n> compute fibonacci(n), n must be >= 0
fibo -bench benchmark fibonacci computation (takes about 1 min)
Additional flags:
-half add values using two half-digit additions
-opt optimize memory allocation through reuse
-short only print the first 10 digits of very large fibonacci numbers
This change was reviewed in detail as https://codereview.appspot.com/168480043 .
Change-Id: I7c86d49c5508532ea6206d00f424cf2117d2fe41
Reviewed-on: https://go-review.googlesource.com/1211
Reviewed-by: Russ Cox <rsc@golang.org>
When we start work on Gerrit, ppc64 and garbage collection
work will continue in the master branch, not the dev branches.
(We may still use dev branches for other things later, but
these are ready to be merged, and doing it now, before moving
to Git means we don't have to have dev branches working
in the Gerrit workflow on day one.)
TBR=rlh
CC=golang-codereviews
https://golang.org/cl/183140043
640 bytes ought to be enough for anybody.
We'll bring this back down before Go 1.5. That's issue 9214.
TBR=rlh
CC=golang-codereviews
https://golang.org/cl/188730043
The SudoG used to sit on the stack, so it was cheap to allocated
and didn't need to be cleaned up when finished.
For the conversion to Go, we had to move sudog off the stack
for a few reasons, so we added a cache of recently used sudogs
to keep allocation cheap. But we didn't add any of the necessary
cleanup before adding a SudoG to the new cache, and so the cached
SudoGs had stale pointers inside them that have caused all sorts
of awful, hard to debug problems.
CL 155760043 made sure SudoG.elem is cleaned up.
CL 150520043 made sure SudoG.selectdone is cleaned up.
This CL makes sure SudoG.next, SudoG.prev, and SudoG.waitlink
are cleaned up. I should have done this when I did the other two
fields; instead I wasted a week tracking down a leak they caused.
A dangling SudoG.waitlink can point into a sudogcache list that
has been "forgotten" in order to let the GC collect it, but that
dangling .waitlink keeps the list from being collected.
And then the list holding the SudoG with the dangling waitlink
can find itself in the same situation, and so on. We end up
with lists of lists of unusable SudoGs that are still linked into
the object graph and never collected (given the right mix of
non-trivial selects and non-channel synchronization).
More details in golang.org/issue/9110.
Fixes#9110.
LGTM=r
R=r
CC=dvyukov, golang-codereviews, iant, khr
https://golang.org/cl/177870043
This is to reduce the delta between dev.cc and dev.garbage to just garbage collector changes.
These are the files that had merge conflicts and have been edited by hand:
malloc.go
mem_linux.go
mgc.go
os1_linux.go
proc1.go
panic1.go
runtime1.go
LGTM=austin
R=austin
CC=golang-codereviews
https://golang.org/cl/174180043
Now the only difference between dev.cc and dev.garbage
is the runtime conversion on the one side and the
garbage collection on the other. They both have the
same set of changes from default and dev.power64.
LGTM=austin
R=austin
CC=golang-codereviews
https://golang.org/cl/172570043
The remaining run-only tests will be migrated to run.go in another CL.
This CL will break the build due to issues 8746 and 8806.
Update #4139
Update #8746
Update #8806
LGTM=rsc
R=rsc, bradfitz, iant
CC=golang-codereviews
https://golang.org/cl/144630044
Now each C printf, Go print, or Go println is guaranteed
not to be interleaved with other calls of those functions.
This should help when debugging concurrent failures.
LGTM=rlh
R=rlh
CC=golang-codereviews
https://golang.org/cl/169120043
One failing case this removes is:
var bytes = []byte("hello, world")
var copy_bytes = bytes
We could handle this in the compiler, but it requires special
case for a variable that is initialized to the value of a
variable that is initialized to a string literal converted to
[]byte. This seems an unlikely case--it never occurs in the
standrd library--and it seems unnecessary to write the code to
handle it.
If we do want to support this case, one approach is
https://golang.org/cl/171840043.
The other failing cases are of the form
var bx bool
var copy_bx = bx
The compiler used to initialize copy_bx to false. However,
that led to issue 7665, since bx may be initialized in non-Go
code. The compiler no longer assumes that bx must be false,
so copy_bx can not be statically initialized.
We can fix these with https://golang.org/cl/169040043
if we also pass -complete to the compiler as part of this
test. This is OK but it's too late in the release cycle.
Fixes#8746.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/165400043
On power64x, this one line in live.go reports that t is live
because of missing optimization passes. This isn't what this
test is trying to test, so shuffle bad40 so that it still
accomplishes the intent of the test without also depending on
optimization.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/167110043
The remaining failures in this test are because of incomplete
optimization support on power64x. Tracked in issue 9058.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/168130043
All three cases of clearfat were wrong on power64x.
The cases that handle 1032 bytes and up and 32 bytes and up
both use MOVDU (one directly generated in a loop and the other
via duffzero), which leaves the pointer register pointing at
the *last written* address. The generated code was not
accounting for this, so the byte fill loop was re-zeroing the
last zeroed dword, rather than the bytes following the last
zeroed dword. Fix this by simply adding an additional 8 byte
offset to the byte zeroing loop.
The case that handled under 32 bytes was also wrong. It
didn't update the pointer register at all, so the byte zeroing
loop was simply re-zeroing the beginning of region. Again,
the fix is to add an offset to the byte zeroing loop to
account for this.
LGTM=dave, bradfitz
R=rsc, dave, bradfitz
CC=golang-codereviews
https://golang.org/cl/168870043
Originally traceback was only used for printing the stack
when an unexpected signal came in. In that case, the
initial PC is taken from the signal and should be used
unaltered. For the callers, the PC is the return address,
which might be on the line after the call; we subtract 1
to get to the CALL instruction.
Traceback is now used for a variety of things, and for
almost all of those the initial PC is a return address,
whether from getcallerpc, or gp->sched.pc, or gp->syscallpc.
In those cases, we need to subtract 1 from this initial PC,
but the traceback code had a hard rule "never subtract 1
from the initial PC", left over from the signal handling days.
Change gentraceback to take a flag that specifies whether
we are tracing a trap.
Change traceback to default to "starting with a return PC",
which is the overwhelmingly common case.
Add tracebacktrap, like traceback but starting with a trap PC.
Use tracebacktrap in signal handlers.
Fixes#7690.
LGTM=iant, r
R=r, iant
CC=golang-codereviews
https://golang.org/cl/167810044
The test just doubled a certain number of times
and then gave up. On a mostly fast but occasionally
slow machine this may never make the test run
long enough to see the linear growth.
Change test to keep doubling until the first round
takes at least a full second, to reduce the effect of
occasional scheduling or other jitter.
The failure we saw had a time for the first round
of around 100ms.
Note that this test still passes once it sees a linear
effect, even with a very small total time.
The timeout here only applies to how long the execution
must be to support a reported failure.
LGTM=khr
R=khr
CC=golang-codereviews, rlh
https://golang.org/cl/164070043
This brings dev.power64 up-to-date with the current tip of
default. go_bootstrap is still panicking with a bad defer
when initializing the runtime (even on amd64).
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/152570049
This also removes pkg/runtime/traceback_lr.c, which was ported
to Go in an earlier commit and then moved to
runtime/traceback.go.
Reviewer: rsc@golang.org
rsc: LGTM
test16 used to fail with gccgo. The withoutRecoverRecursive
test would have failed in some possible implementations.
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/151630043
This brings cmd/gc in line with the spec on this question.
It might break existing code, but that code was not conformant
with the spec.
Credit to Rémy for finding the broken code.
Fixes#6366.
LGTM=r
R=golang-codereviews, r
CC=adonovan, golang-codereviews, gri
https://golang.org/cl/129550043
https://golang.org/cl/152700045/ made it possible for struct literals assigned to globals to use <N> as the RHS. Normally, this is to zero out variables on first use. Because globals are already zero (or their linker initialized value), we just ignored this.
Now that <N> can occur from non-initialization code, we need to emit this code. We don't use <N> for initialization of globals any more, so this shouldn't cause any excessive zeroing.
Fixes#8961.
LGTM=rsc
R=golang-codereviews, rsc
CC=bradfitz, golang-codereviews
https://golang.org/cl/154540044
This fixes the bug in which the linker reports "missing Go
type information" when a -X option refers to a symbol that is
not used.
Fixes#8821.
LGTM=rsc
R=rsc, r
CC=golang-codereviews
https://golang.org/cl/151000043
If there is a leading ·, assume there is a Go prototype and
attach the Go prototype information to the function.
If the function is not called from Go and does not need a
Go prototype, it can be made file-local instead (using name<>(SB)).
This fixes the current BSD build failures, by giving functions like
sync/atomic.StoreUint32 argument stack map information.
Fixes#8753.
LGTM=khr, iant
R=golang-codereviews, iant, khr, bradfitz
CC=golang-codereviews, r, rlh
https://golang.org/cl/142150043
iterdelete's run time varies; occasionally we get unlucky. To reduce spurious failures, average away some of the variation.
On my machine, 8 of 5000 runs (0.15%) failed before this CL. After this CL, there were no failures after 35,000 runs.
I confirmed that this adjusted test still fails before CL 141270043.
LGTM=khr
R=khr
CC=bradfitz, golang-codereviews
https://golang.org/cl/140610043
During anylit run, nodes such as SLICEARR(statictmp, [:])
may be generated and are expected to be found unchanged by
gen_as_init.
In some walks (in particular walkselect), the statement
may be walked again and lowered to its usual form, leading to a
crash.
Fixes#8017.
Fixes#8024.
Fixes#8058.
LGTM=rsc
R=golang-codereviews, dvyukov, gobot, rsc
CC=golang-codereviews
https://golang.org/cl/112080043
Previously it might happen before calling dowidth and
result in a compiler crash.
Fixes#8060.
LGTM=dvyukov, rsc
R=golang-codereviews, dvyukov, gobot, rsc
CC=golang-codereviews
https://golang.org/cl/110980044
A write *p = x that needs a write barrier (not all do)
now turns into runtime.writebarrierptr(p, x)
or one of the other variants.
The write barrier implementations are trivial.
The goal here is to emit the calls in the correct places
and to incur the cost of those function calls in the Go 1.4 cycle.
Performance on the Go 1 benchmark suite below.
Remember, the goal is to slow things down (and be correct).
We will look into optimizations in separate CLs, as part of
the process of comparing Go 1.3 against tip in order to make
sure Go 1.4 runs at least as fast as Go 1.3.
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 3118336716 3452876110 +10.73%
BenchmarkFannkuch11 3184497677 3211552284 +0.85%
BenchmarkFmtFprintfEmpty 89.9 107 +19.02%
BenchmarkFmtFprintfString 236 287 +21.61%
BenchmarkFmtFprintfInt 246 278 +13.01%
BenchmarkFmtFprintfIntInt 395 458 +15.95%
BenchmarkFmtFprintfPrefixedInt 343 378 +10.20%
BenchmarkFmtFprintfFloat 477 525 +10.06%
BenchmarkFmtManyArgs 1446 1707 +18.05%
BenchmarkGobDecode 14398047 14685958 +2.00%
BenchmarkGobEncode 12557718 12947104 +3.10%
BenchmarkGzip 453462345 472413285 +4.18%
BenchmarkGunzip 114226016 115127398 +0.79%
BenchmarkHTTPClientServer 114689 112122 -2.24%
BenchmarkJSONEncode 24914536 26135942 +4.90%
BenchmarkJSONDecode 86832877 103620289 +19.33%
BenchmarkMandelbrot200 4833452 4898780 +1.35%
BenchmarkGoParse 4317976 4835474 +11.98%
BenchmarkRegexpMatchEasy0_32 150 166 +10.67%
BenchmarkRegexpMatchEasy0_1K 393 402 +2.29%
BenchmarkRegexpMatchEasy1_32 125 142 +13.60%
BenchmarkRegexpMatchEasy1_1K 1010 1236 +22.38%
BenchmarkRegexpMatchMedium_32 232 301 +29.74%
BenchmarkRegexpMatchMedium_1K 76963 102721 +33.47%
BenchmarkRegexpMatchHard_32 3833 5463 +42.53%
BenchmarkRegexpMatchHard_1K 119668 161614 +35.05%
BenchmarkRevcomp 763449047 706768534 -7.42%
BenchmarkTemplate 124954724 134834549 +7.91%
BenchmarkTimeParse 517 511 -1.16%
BenchmarkTimeFormat 501 514 +2.59%
benchmark old MB/s new MB/s speedup
BenchmarkGobDecode 53.31 52.26 0.98x
BenchmarkGobEncode 61.12 59.28 0.97x
BenchmarkGzip 42.79 41.08 0.96x
BenchmarkGunzip 169.88 168.55 0.99x
BenchmarkJSONEncode 77.89 74.25 0.95x
BenchmarkJSONDecode 22.35 18.73 0.84x
BenchmarkGoParse 13.41 11.98 0.89x
BenchmarkRegexpMatchEasy0_32 213.30 191.72 0.90x
BenchmarkRegexpMatchEasy0_1K 2603.92 2542.74 0.98x
BenchmarkRegexpMatchEasy1_32 254.00 224.93 0.89x
BenchmarkRegexpMatchEasy1_1K 1013.53 827.98 0.82x
BenchmarkRegexpMatchMedium_32 4.30 3.31 0.77x
BenchmarkRegexpMatchMedium_1K 13.30 9.97 0.75x
BenchmarkRegexpMatchHard_32 8.35 5.86 0.70x
BenchmarkRegexpMatchHard_1K 8.56 6.34 0.74x
BenchmarkRevcomp 332.92 359.62 1.08x
BenchmarkTemplate 15.53 14.39 0.93x
LGTM=rlh
R=rlh
CC=dvyukov, golang-codereviews, iant, khr, r
https://golang.org/cl/136380043
