SSA compiler on AMD64 may spill Duff-adjusted address as scalar. If
the object is on stack and the stack moves, the spilled address become
invalid.
Making the spill pointer-typed does not work. The Duff-adjusted address
points to the memory before the area to be zeroed and may be invalid.
This may cause stack scanning code panic.
Fix it by doing Duff-adjustment in genValue, so the intermediate value
is not seen by the reg allocator, and will not be spilled.
Add a test to cover both cases. As it depends on allocation, it may
be not always triggered.
Fixes#16515.
Change-Id: Ia81d60204782de7405b7046165ad063384ede0db
Reviewed-on: https://go-review.googlesource.com/25309
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Updates #16396
Change-Id: I7b4f85610e66f2c77c17cf8898cc41d81b2efc8c
Reviewed-on: https://go-review.googlesource.com/25283
Reviewed-by: Chris Broadfoot <cbro@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
Apparently the old backend needs NEG instruction having RegRead set,
even this instruction does not take a Reg field... I don't think SSA
uses this flag, so just leave it as it was. SSA is still happy.
Fix ARM64 build on https://build.golang.org/?branch=dev.ssa
Change-Id: Ia7e7f2ca217ddae9af314d346af5406bbafb68e8
Reviewed-on: https://go-review.googlesource.com/25302
Reviewed-by: David Chase <drchase@google.com>
Mutator goroutines that allocate memory during the concurrent mark
phase are required to spend some time assisting the garbage
collector. The magnitude of this mandatory assistance is proportional
to the goroutine's allocation debt and subject to the assistance
ratio as calculated by the pacer.
When assisting the garbage collector, a mutator goroutine will go
beyond paying off its allocation debt. It will build up extra credit
to amortize the overhead of the assist.
In fast-allocating applications with high assist ratios, building up
this credit can take the affected goroutine's entire time slice.
Reduce the penalty on each goroutine being selected to assist the GC
in two ways, to spread the responsibility more evenly.
First, do a consistent amount of extra scan work without regard for
the pacer's assistance ratio. Second, reduce the magnitude of the
extra scan work so it can be completed within a few hundred
microseconds.
Commentary on gcOverAssistWork is by Austin Clements, originally in
https://golang.org/cl/24704
Updates #14812Fixes#16432
Change-Id: I436f899e778c20daa314f3e9f0e2a1bbd53b43e1
Reviewed-on: https://go-review.googlesource.com/25155
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>
Instead of comparing the address of the end of the memory to zero/copy,
comparing the address of the last element, which is a valid pointer.
Also unify large and unaligned Zero/Move, by passing alignment as AuxInt.
Fixes#16515 for ARM.
Change-Id: I19a62b31c5acf5c55c16a89bea1039c926dc91e5
Reviewed-on: https://go-review.googlesource.com/25300
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Support the following:
- Shifts. ARM64 machine instructions only use lowest 6 bits of the
shift (i.e. mod 64). Use conditional selection instruction to
ensure Go semantics.
- Zero/Move. Alignment is ensured.
- Hmul, Avg64u, Sqrt.
- reserve R18 (platform register in ARM64 ABI) and R29 (frame pointer
in ARM64 ABI).
Everything compiles, all.bash passed (with non-SSA test disabled).
Change-Id: Ia8ed58dae5cbc001946f0b889357b258655078b1
Reviewed-on: https://go-review.googlesource.com/25290
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
https://golang.org/cl/25233 was detecting the OS X release at compile
time, not run time. Detect it at run time instead.
Fixes#16473 (again)
Change-Id: I6bec4996e57aa50c52599c165aa6f1fae7423fa7
Reviewed-on: https://go-review.googlesource.com/25281
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>
Updates x/net/http2 to git rev 6a513af for:
http2: return flow control for closed streams
https://golang.org/cl/25231
http2: make Transport prefer HTTP response header recv before body write error
https://golang.org/cl/24984
http2: make Transport treat "Connection: close" the same as Request.Close
https://golang.org/cl/24982Fixesgolang/go#16481
Change-Id: Iaddb166387ca2df1cfbbf09a166f8605578bec49
Reviewed-on: https://go-review.googlesource.com/25282
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
Currently the pprof package gives almost no guidance for how to use it
and, despite the standard boilerplate used to create CPU and memory
profiles, this boilerplate appears nowhere in the pprof documentation.
Update the pprof package documentation to give the standard
boilerplate in a form people can copy, paste, and tweak. This
boilerplate is based on rsc's 2011 blog post on profiling Go programs
at https://blog.golang.org/profiling-go-programs, which is where I
always go when I need to copy-paste the boilerplate.
Change-Id: I74021e494ea4dcc6b56d6fb5e59829ad4bb7b0be
Reviewed-on: https://go-review.googlesource.com/25182
Reviewed-by: Rick Hudson <rlh@golang.org>
Conservative fix for the OS X 10.8 crash. We can unify them back together
during the Go 1.8 dev cycle.
Fixes#16473
Change-Id: If07228deb2be36093dd324b3b3bcb31c23a95035
Reviewed-on: https://go-review.googlesource.com/25233
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
Added support for ClosureCall, DeferCall, InterCall
(GoCall not yet tested).
Added support for GetClosurePtr, IsNonNil, IsInBounds, IsSliceInBounds, NilCheck
(Convert and GetG not yet tested)
Still need to implement NilCheck optimizations.
Fixed move boolean constant, order of operands to subtract.
Updates #16010.
Change-Id: Ibe0f6a6e688df4396cd77de0e9095997e4ca8ed2
Reviewed-on: https://go-review.googlesource.com/25241
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Adds a test case for calling context.WithDeadline() where the deadline
exists in the past. This change increases the code coverage of the
context package.
Change-Id: Ib486bf6157e779fafd9dab2b7364cdb5a06be36e
Reviewed-on: https://go-review.googlesource.com/25007
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Sameer Ajmani <sameer@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
From at least Go 1.4 to Go 1.6, Transport.RoundTrip would return the
error value from net.Conn.Read directly when the initial Read (1 byte
Peek) failed while reading the HTTP response, if a request was
outstanding. While never a documented or tested promise, Go 1.7 changed the
behavior (starting at https://golang.org/cl/23160).
This restores the old behavior and adds a test (but no documentation
promises yet) while keeping the fix for spammy logging reported in #15446.
This looks larger than it is: it just changes errServerClosedConn from
a variable to a type, where the type preserves the underlying
net.Conn.Read error, for unwrapping later in Transport.RoundTrip.
Fixes#16465
Change-Id: I6fa018991221e93c0cfe3e4129cb168fbd98bd27
Reviewed-on: https://go-review.googlesource.com/25153
Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Because PPC lacks store-immediate, remove the instruction
that implies that it exists. Replace it with storezero for
the special case of storing zero, because R0 is reserved zero
for Go (though the assembler knows this, do it in SSA).
Also added address folding for storezero.
(Now corrected to use right-sized stores in bulk-zero code.)
Hello.go now compiles to
genssa main
00000 (...hello.go:7) TEXT "".main(SB), $0
00001 (...hello.go:7) FUNCDATA $0, "".gcargs·0(SB)
00002 (...hello.go:7) FUNCDATA $1, "".gclocals·1(SB)
v23 00003 (...hello.go:8) MOVD $go.string."Hello, World!\n"(SB), R3
v11 00004 (...hello.go:8) MOVD R3, 32(R1)
v22 00005 (...hello.go:8) MOVD $14, R3
v6 00006 (...hello.go:8) MOVD R3, 40(R1)
v20 00007 (...hello.go:8) MOVD R0, 48(R1)
v18 00008 (...hello.go:8) MOVD R0, 56(R1)
v9 00009 (...hello.go:8) MOVD R0, 64(R1)
v10 00010 (...hello.go:8) CALL fmt.Printf(SB)
b2 00011 (...hello.go:9) RET
00012 (<unknown line number>) END
Updates #16010
Change-Id: I33cfd98c21a1617502260ac753fa8cad68c8d85a
Reviewed-on: https://go-review.googlesource.com/25151
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Mostly copied from ARM port, with instruction names and Prog fields
adjusted, and 64-bit int ops added. Not complete.
Fib compiles and runs correctly.
Change-Id: Id3ecb0d4b571200a035344b3e8e4408769f76221
Reviewed-on: https://go-review.googlesource.com/25130
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Noticed when investigating a separate issue.
No external bug report or repro yet.
Change-Id: I8a1641a43163f22b09accd3beb25dd9e2a68a238
Reviewed-on: https://go-review.googlesource.com/25152
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
GOARCH=386 SSATEST=1 ./all.bash passes
Caveat: still needs changes to test/ files to use *_ssa.go versions. I
won't check those changes in with this CL because the builders will
complain as they don't have SSATEST=1.
Mostly minor fixes.
Implement float <-> uint32 in assembly. It seems the simplest option
for now.
GO386=387 does not work. That's why I can't make SSA the default for
386 yet.
Change-Id: Ic4d4402104d32bcfb1fd612f5bb6539f9acb8ae0
Reviewed-on: https://go-review.googlesource.com/25119
Reviewed-by: Cherry Zhang <cherryyz@google.com>
It was removed in upstream Chrome https://codereview.chromium.org/2016863004
Rather than update to the latest version, make the minimal change for Go 1.7 and
change the "showToUser" boolean from true to false.
Tested by hand that it goes away after this change.
Updates #16247
Change-Id: I051f49da878e554b1a34a88e9abc70ab50e18780
Reviewed-on: https://go-review.googlesource.com/25117
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
For register-register move, if there is only one use, allocate it in
the same register so we don't need to emit an instruction.
Updates #15365.
Change-Id: Iad41843854a506c521d577ad93fcbe73e8de8065
Reviewed-on: https://go-review.googlesource.com/25059
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
This is:
(1) a simple trick that cuts the number of phi-nodes
(temporarily) inserted into the ssa representation by a factor
of 10, and can cut the user time to compile tricky inputs like
gogo/protobuf tests from 13 user minutes to 9.5, and memory
allocation from 3.4GB to 2.4GB.
(2) a fix to sparse lookup, that does not rely on
an assumption proven false by at least one pathological
input "etldlen".
These two changes fix unrelated compiler performance bugs,
both necessary to obtain good performance compiling etldlen.
Without them it takes 20 minutes or longer, with them it
completes in 2 minutes, without a gigantic memory footprint.
Updates #16407
Change-Id: Iaa8aaa8c706858b3d49de1c4865a7fd79e6f4ff7
Reviewed-on: https://go-review.googlesource.com/23136
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
entry:
x = MOVQconst [7]
...
b1:
goto b2
b2:
v = Phi(x, y, z)
Transform that program to:
entry:
...
b1:
x = MOVQconst [7]
goto b2
b2:
v = Phi(x, y, z)
This CL moves constant-generating instructions used by a phi to the
appropriate immediate predecessor of the phi's block.
We used to put all constants in the entry block. Unfortunately, in
large functions we have lots of constants at the start of the
function, all of which are used by lots of phis throughout the
function. This leads to the constants being live through most of the
function (especially if there is an outer loop). That's an O(n^2)
problem.
Note that most of the non-phi uses of constants have already been
folded into instructions (ADDQconst, MOVQstoreconst, etc.).
This CL may be generally useful for other instances of compiler
slowness, I'll have to check. It may cause some programs to run
slower, but probably not by much, as rematerializeable values like
these constants are allocated late (not at their originally scheduled
location) anyway.
This CL is definitely a minimal change that can be considered for 1.7.
We probably want to do a better job in the tighten pass generally, not
just for phi args. Leaving that for 1.8.
Update #16407
Change-Id: If112a8883b4ef172b2f37dea13e44bda9346c342
Reviewed-on: https://go-review.googlesource.com/25046
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
The omission of this instruction could confuse the traceback code if a
SIGPROF occurred during a signal handler. The traceback code would
trace up to sigtramp, but would then get confused because it would see a
PC address that did not appear to be in the function.
Fixes#16453.
Change-Id: I2b3d53e0b272fb01d9c2cb8add22bad879d3eebc
Reviewed-on: https://go-review.googlesource.com/25104
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Most operations need an upper bound on the physical page size, which
is what sys.PhysPageSize is for (this is checked at runtime init on
Linux). However, a few operations need a *lower* bound on the physical
page size. Introduce a "minPhysPageSize" constant to act as this lower
bound and use it where it makes sense:
1) In addrspace_free, we have to query each page in the given range.
Currently we increment by the upper bound on the physical page
size, which means we may skip over pages if the true size is
smaller. Worse, we currently pass a result buffer that only has
enough room for one page. If there are actually multiple pages in
the range passed to mincore, the kernel will overflow this buffer.
Fix these problems by incrementing by the lower-bound on the
physical page size and by passing "1" for the length, which the
kernel will round up to the true physical page size.
2) In the write barrier, the bad pointer check tests for pointers to
the first physical page, which are presumably small integers
masquerading as pointers. However, if physical pages are smaller
than we think, we may have legitimate pointers below
sys.PhysPageSize. Hence, use minPhysPageSize for this test since
pointers should never fall below that.
In particular, this applies to ARM64 and MIPS. The runtime is
configured to use 64kB pages on ARM64, but by default Linux uses 4kB
pages. Similarly, the runtime assumes 16kB pages on MIPS, but both 4kB
and 16kB kernel configurations are common. This also applies to ARM on
systems where the runtime is recompiled to deal with a larger page
size. It is also a step toward making the runtime use only a
dynamically-queried page size.
Change-Id: I1fdfd18f6e7cbca170cc100354b9faa22fde8a69
Reviewed-on: https://go-review.googlesource.com/25020
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Austin Clements <austin@google.com>
When a non-Go thread calls into Go, the runtime needs an M to run the Go
code. The runtime keeps a list of extra M's available. When the last
extra M is allocated, the needextram field is set to tell it to allocate
a new extra M as soon as it is running in Go. This ensures that an extra
M will always be available for the next thread.
However, if many threads need an extra M at the same time, this
serializes them all. One thread will get an extra M with the needextram
field set. All the other threads will see that there is no M available
and will go to sleep. The one thread that succeeded will create a new
extra M. One lucky thread will get it. All the other threads will see
that there is no M available and will go to sleep. The effect is
thundering herd, as all the threads looking for an extra M go through
the process one by one. This seems to have a particularly bad effect on
the FreeBSD scheduler for some reason.
With this change, we track the number of threads waiting for an M, and
create all of them as soon as one thread gets through. This still means
that all the threads will fight for the lock to pick up the next M. But
at least each thread that gets the lock will succeed, instead of going
to sleep only to fight again.
This smooths out the performance greatly on FreeBSD, reducing the
average wall time of `testprogcgo CgoCallbackGC` by 74%. On GNU/Linux
the average wall time goes down by 9%.
Fixes#13926Fixes#16396
Change-Id: I6dc42a4156085a7ed4e5334c60b39db8f8ef8fea
Reviewed-on: https://go-review.googlesource.com/25047
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
This copies the frozen wording from the log/syslog package.
Fixes#16436
Change-Id: If5d478023328925299399f228d8aaf7fb117c1b4
Reviewed-on: https://go-review.googlesource.com/25080
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
Fix up zero/move code, including duff calls and rep movs.
Handle the new ops generated by dec64.rules.
Fix constant shifts.
Change-Id: I7d89194b29b04311bfafa0fd93b9f5644af04df9
Reviewed-on: https://go-review.googlesource.com/25033
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Rather than saying "stop-the-world", say "garbage collection pauses".
Change-Id: Ifb2931781ab3094e04bea93f01f18f1acb889bdc
Reviewed-on: https://go-review.googlesource.com/25018
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
We now allow Values to have 2 outputs. Use that ability for amd64.
This allows x,y := a/b,a%b to use just a single divide instruction.
Update #6815
Change-Id: Id70bcd20188a2dd8445e631a11d11f60991921e4
Reviewed-on: https://go-review.googlesource.com/25004
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Make tuple types and their SelectX ops fully generic.
These ops no longer need to be lowered.
Regalloc understands them and their tuple-generating arguments.
We can now have opcodes returning arbitrary pairs of results.
(And it would be easy to move to >2 results if needed.)
Update arm implementation to the new standard.
Implement just enough in 386 port to do 64-bit add.
Change-Id: I370ed5aacce219c82e1954c61d1f63af76c16f79
Reviewed-on: https://go-review.googlesource.com/24976
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Because,
* The CGI spec defines that incoming request header "Foo: Bar" maps to
environment variable HTTP_FOO == "Bar". (see RFC 3875 4.1.18)
* The HTTP_PROXY environment variable is conventionally used to configure
the HTTP proxy for HTTP clients (and is respected by default for
Go's net/http.Client and Transport)
That means Go programs running in a CGI environment (as a child
process under a CGI host) are vulnerable to an incoming request
containing "Proxy: attacker.com:1234", setting HTTP_PROXY, and
changing where Go by default proxies all outbound HTTP requests.
This is CVE-2016-5386, aka https://httpoxy.org/Fixes#16405
Change-Id: I6f68ade85421b4807785799f6d98a8b077e871f0
Reviewed-on: https://go-review.googlesource.com/25010
Run-TryBot: Chris Broadfoot <cbro@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>
Reviewed-on: https://go-review.googlesource.com/25013
Because,
* The CGI spec defines that incoming request header "Foo: Bar" maps to
environment variable HTTP_FOO == "Bar". (see RFC 3875 4.1.18)
* The HTTP_PROXY environment variable is conventionally used to configure
the HTTP proxy for HTTP clients (and is respected by default for
Go's net/http.Client and Transport)
That means Go programs running in a CGI environment (as a child
process under a CGI host) are vulnerable to an incoming request
containing "Proxy: attacker.com:1234", setting HTTP_PROXY, and
changing where Go by default proxies all outbound HTTP requests.
This is CVE-2016-5386, aka https://httpoxy.org/Fixes#16405
Change-Id: I6f68ade85421b4807785799f6d98a8b077e871f0
Reviewed-on: https://go-review.googlesource.com/25010
Run-TryBot: Chris Broadfoot <cbro@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>
Most of the runtime improvements are hard to quantify or summarize,
but it's worth mentioning some of the substantial improvements in STW
time, and that the scavenger now actually works on ARM64, PPC64, and
MIPS.
Change-Id: I0e951038516378cc3f95b364716ef1c183f3445a
Reviewed-on: https://go-review.googlesource.com/24966
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Only run TestDialerDualStack on the builders, as to not annoy or
otherwise distract users when it's not their fault.
Even though the intention is to only run this on the builders, very
few of the builders have IPv6 support. Oh well. We'll get some
coverage.
Updates #13324
Change-Id: I13e7e3bca77ac990d290cabec88984cc3d24fb67
Reviewed-on: https://go-review.googlesource.com/24985
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Change https://golang.org/cl/19895 caused a regression
where the last character in a string would be dropped if it was
accompanied by an io.EOF.
This change fixes the logic so that the last byte is still returned
without a problem.
Fixes#16393
Change-Id: I7a4d0abf761c2c15454136a79e065fe002d736ea
Reviewed-on: https://go-review.googlesource.com/24981
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
