Stack barriers were removed in CL 36620.
Change-Id: If124d65a73a7b344a42be2a4b386a14d7a0a428b
Reviewed-on: https://go-review.googlesource.com/38169
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: David Chase <drchase@google.com>
This matches the error message of cmd/compile (for assignments).
Change-Id: I42a428f5d72f034e7b7e97b090a929e317e812af
Reviewed-on: https://go-review.googlesource.com/38315
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
See https://go-review.googlesource.com/#/c/38313/ for background.
It turns out that only a few tests checked for this.
The new error message is shorter and very clear.
Change-Id: I8ab4ad59fb023c8b54806339adc23aefd7dc7b07
Reviewed-on: https://go-review.googlesource.com/38314
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This is an evolution of https://go-review.googlesource.com/33616, as discussed
via email with Robert (gri):
$ cat foobar.go
package main
func main() {
a := "foo", "bar"
}
before:
./foobar.go:4:4: assignment count mismatch: want 1 values, got 2
after:
./foobar.go:4:4: assignment count mismatch: cannot assign 2 values to 1 variables
We could likely also eliminate the "assignment count mismatch" prefix now
without losing any information, but that string is matched by a number of
tests.
Change-Id: Ie6fc8a7bbd0ebe841d53e66e5c2f49868decf761
Reviewed-on: https://go-review.googlesource.com/38313
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
name old time/op new time/op delta
LeadingZeros-4 2.00ns ± 0% 1.34ns ± 1% -33.02% (p=0.000 n=8+10)
LeadingZeros16-4 1.62ns ± 0% 1.57ns ± 0% -3.09% (p=0.001 n=8+9)
LeadingZeros32-4 2.14ns ± 0% 1.48ns ± 0% -30.84% (p=0.002 n=8+10)
LeadingZeros64-4 2.06ns ± 1% 1.33ns ± 0% -35.08% (p=0.000 n=8+8)
8-bit args is a special case - the Go code is really fast because
it is just a single table lookup. So I've disabled that for now.
Intrinsics were actually slower:
LeadingZeros8-4 1.22ns ± 3% 1.58ns ± 1% +29.56% (p=0.000 n=10+10)
Update #18616
Change-Id: Ia9c289b9ba59c583ea64060470315fd637e814cf
Reviewed-on: https://go-review.googlesource.com/38311
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Updates #17802
Change-Id: I65ea0f4cde973604c04051e7eb25d12e4facecd3
Reviewed-on: https://go-review.googlesource.com/36626
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>
Remove size AuxInt in Store, and alignment in Move/Zero. We still
pass size AuxInt to Move/Zero, as it is used for partial Move/Zero
lowering (e.g. cmd/compile/internal/ssa/gen/386.rules:288).
SizeAndAlign is gone.
Passes "toolstash -cmp" on std.
Change-Id: I1ca34652b65dd30de886940e789fcf41d521475d
Reviewed-on: https://go-review.googlesource.com/38150
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The old writebarrier implementation fails to handle single-block
loop where a memory Phi value depends on the write barrier store
in the same block. The new implementation (CL 36834) doesn't have
this problem. Add a test to ensure it.
Fix#19067.
Change-Id: Iab13c6817edc12be8a048d18699b4450fa7ed712
Reviewed-on: https://go-review.googlesource.com/36940
Reviewed-by: David Chase <drchase@google.com>
Now that the write barrier insertion is moved to SSA, the SSA
building code can be simplified.
Updates #17583.
Change-Id: I5cacc034b11aa90b0abe6f8dd97e4e3994e2bc25
Reviewed-on: https://go-review.googlesource.com/36840
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
When the compiler insert write barriers, the frontend makes
conservative decisions at an early stage. This sometimes have
false positives because of the lack of information, for example,
writes on stack. SSA's writebarrier pass identifies writes on
stack and eliminates write barriers for them.
This CL moves write barrier insertion into SSA. The frontend no
longer makes decisions about write barriers, and simply does
normal assignments and emits normal Store ops when building SSA.
SSA writebarrier pass inserts write barrier for Stores when needed.
There, it has better information about the store because Phi and
Copy propagation are done at that time.
This CL only changes StoreWB to Store in gc/ssa.go. A followup CL
simplifies SSA building code.
Updates #17583.
Change-Id: I4592d9bc0067503befc169c50b4e6f4765673bec
Reviewed-on: https://go-review.googlesource.com/36839
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
For SSA Store/Move/Zero ops, attach the type of the value being
stored to the op as the Aux field. This type will be used for
write barrier insertion (in a followup CL). Since SSA passes
do not accurately propagate types of values (because of type
casting), we can't simply use type of the store's arguments
for write barrier insertion.
Passes "toolstash -cmp" on std.
Updates #17583.
Change-Id: I051d5e5c482931640d1d7d879b2a6bb91f2e0056
Reviewed-on: https://go-review.googlesource.com/36838
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Implement math/bits.TrailingZerosX using intrinsics.
Generally reorganize the intrinsic spec a bit.
The instrinsics data structure is now built at init time.
This will make doing the other functions in math/bits easier.
Update sys.CtzX to return int instead of uint{64,32} so it
matches math/bits.TrailingZerosX.
Improve the intrinsics a bit for amd64. We don't need the CMOV
for <64 bit versions.
Update #18616
Change-Id: Ic1c5339c943f961d830ae56f12674d7b29d4ff39
Reviewed-on: https://go-review.googlesource.com/38155
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Currently, when printing tracebacks of other threads during
GOTRACEBACK=crash, if the thread is on the system stack we print only
the header for the user goroutine and fail to print its stack. This
happens because we passed the g0 to traceback instead of curg. The g0
never has anything set in its gobuf, so traceback doesn't print
anything.
Fix this by passing _g_.m.curg to traceback instead of the g0.
Fixes#19494.
Change-Id: Idfabf94d6a725e9cdf94a3923dead6455ef3b217
Reviewed-on: https://go-review.googlesource.com/38012
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
GOTRACEBACK=crash works by bouncing a SIGQUIT around the process
sched.mcount times. However, sched.mcount includes the extra Ms
allocated by oneNewExtraM for cgo callbacks. Hence, if there are any
extra Ms that don't have real OS threads, we'll try to send SIGQUIT
more times than there are threads to catch it. Since nothing will
catch these extra signals, we'll fall back to blocking for five
seconds before aborting the process.
Avoid this five second delay by subtracting out the number of extra Ms
when sending SIGQUITs.
Of course, in a cgo binary, it's still possible for the SIGQUIT to go
to a cgo thread and cause some other failure mode. This does not fix
that.
Change-Id: I4fbf3c52dd721812796c4c1dcb2ab4cb7026d965
Reviewed-on: https://go-review.googlesource.com/38182
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Put call stubs at the beginning (instead of the end). So the
trampoline pass knows the addresses of the stubs, and it can
insert trampolines when necessary.
Fixes#19425.
Change-Id: I1e06529ef837a6130df58917315610d45a6819ca
Reviewed-on: https://go-review.googlesource.com/38131
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
The line between ssa.Func and ssa.Config has blurred.
Concurrent compilation in the backend will require more precision.
This CL lays out an (aspirational) organization.
The implementation will come in follow-up CLs,
once the organization is settled.
ssa.Config holds basic compiler configuration,
mostly arch-specific information.
It is configured once, early on, and is readonly,
so it is safe for concurrent use.
ssa.Func is a single-shot object used for
compiling a single Func. It is not concurrency-safe
and not re-usable.
ssa.Cache is a multi-use object used to avoid
expensive allocations during compilation.
Each ssa.Func is given an ssa.Cache to use.
ssa.Cache is not concurrency-safe.
Change-Id: Id02809b6f3541541cac6c27bbb598834888ce1cc
Reviewed-on: https://go-review.googlesource.com/38160
Reviewed-by: Keith Randall <khr@golang.org>
Previously we always issued a spill right after the op
that was being spilled. This CL pushes spills father away
from the generator, hopefully pushing them into unlikely branches.
For example:
x = ...
if unlikely {
call ...
}
... use x ...
Used to compile to
x = ...
spill x
if unlikely {
call ...
restore x
}
It now compiles to
x = ...
if unlikely {
spill x
call ...
restore x
}
This is particularly useful for code which appends, as the only
call is an unlikely call to growslice. It also helps for the
spills needed around write barrier calls.
The basic algorithm is walk down the dominator tree following a
path where the block still dominates all of the restores. We're
looking for a block that:
1) dominates all restores
2) has the value being spilled in a register
3) has a loop depth no deeper than the value being spilled
The walking-down code is iterative. I was forced to limit it to
searching 100 blocks so it doesn't become O(n^2). Maybe one day
we'll find a better way.
I had to delete most of David's code which pushed spills out of loops.
I suspect this CL subsumes most of the cases that his code handled.
Generally positive performance improvements, but hard to tell for sure
with all the noise. (compilebench times are unchanged.)
name old time/op new time/op delta
BinaryTree17-12 2.91s ±15% 2.80s ±12% ~ (p=0.063 n=10+10)
Fannkuch11-12 3.47s ± 0% 3.30s ± 4% -4.91% (p=0.000 n=9+10)
FmtFprintfEmpty-12 48.0ns ± 1% 47.4ns ± 1% -1.32% (p=0.002 n=9+9)
FmtFprintfString-12 85.6ns ±11% 79.4ns ± 3% -7.27% (p=0.005 n=10+10)
FmtFprintfInt-12 91.8ns ±10% 85.9ns ± 4% ~ (p=0.203 n=10+9)
FmtFprintfIntInt-12 135ns ±13% 127ns ± 1% -5.72% (p=0.025 n=10+9)
FmtFprintfPrefixedInt-12 167ns ± 1% 168ns ± 2% ~ (p=0.580 n=9+10)
FmtFprintfFloat-12 249ns ±11% 230ns ± 1% -7.32% (p=0.000 n=10+10)
FmtManyArgs-12 504ns ± 7% 506ns ± 1% ~ (p=0.198 n=9+9)
GobDecode-12 6.95ms ± 1% 7.04ms ± 1% +1.37% (p=0.001 n=10+10)
GobEncode-12 6.32ms ±13% 6.04ms ± 1% ~ (p=0.063 n=10+10)
Gzip-12 233ms ± 1% 235ms ± 0% +1.01% (p=0.000 n=10+9)
Gunzip-12 40.1ms ± 1% 39.6ms ± 0% -1.12% (p=0.000 n=10+8)
HTTPClientServer-12 227µs ± 9% 221µs ± 5% ~ (p=0.114 n=9+8)
JSONEncode-12 16.1ms ± 2% 15.8ms ± 1% -2.09% (p=0.002 n=9+8)
JSONDecode-12 61.8ms ±11% 57.9ms ± 1% -6.30% (p=0.000 n=10+9)
Mandelbrot200-12 4.30ms ± 3% 4.28ms ± 1% ~ (p=0.203 n=10+8)
GoParse-12 3.18ms ± 2% 3.18ms ± 2% ~ (p=0.579 n=10+10)
RegexpMatchEasy0_32-12 76.7ns ± 1% 77.5ns ± 1% +0.92% (p=0.002 n=9+8)
RegexpMatchEasy0_1K-12 239ns ± 3% 239ns ± 1% ~ (p=0.204 n=10+10)
RegexpMatchEasy1_32-12 71.4ns ± 1% 70.6ns ± 0% -1.15% (p=0.000 n=10+9)
RegexpMatchEasy1_1K-12 383ns ± 2% 390ns ±10% ~ (p=0.181 n=8+9)
RegexpMatchMedium_32-12 114ns ± 0% 113ns ± 1% -0.88% (p=0.000 n=9+8)
RegexpMatchMedium_1K-12 36.3µs ± 1% 36.8µs ± 1% +1.59% (p=0.000 n=10+8)
RegexpMatchHard_32-12 1.90µs ± 1% 1.90µs ± 1% ~ (p=0.341 n=10+10)
RegexpMatchHard_1K-12 59.4µs ±11% 57.8µs ± 1% ~ (p=0.968 n=10+9)
Revcomp-12 461ms ± 1% 462ms ± 1% ~ (p=1.000 n=9+9)
Template-12 67.5ms ± 1% 66.3ms ± 1% -1.77% (p=0.000 n=10+8)
TimeParse-12 314ns ± 3% 309ns ± 0% -1.56% (p=0.000 n=9+8)
TimeFormat-12 340ns ± 2% 331ns ± 1% -2.79% (p=0.000 n=10+10)
The go binary is 0.2% larger. Not really sure why the size
would change.
Change-Id: Ia5116e53a3aeb025ef350ffc51c14ae5cc17871c
Reviewed-on: https://go-review.googlesource.com/34822
Reviewed-by: David Chase <drchase@google.com>
Interface wrapper functions now get compiled eagerly in some cases.
Consequently, they may be present in multiple translation units.
Mark them as DUPOK, just like closures.
Fixes#19548Fixes#19550
Change-Id: Ibe74adb5a62dbf6447db37fde22dcbb3479969ef
Reviewed-on: https://go-review.googlesource.com/38156
Reviewed-by: David Chase <drchase@google.com>
In the SSA CFG, TEXT, RET, and JMP instructions correspond to Blocks,
not Values. Rework liveness analysis so that progeffects only cares
about Progs that result from Values, and handle Blocks separately.
Passes toolstash-check -all.
Change-Id: Ic23719c75b0421fdb51382a08dac18c3ba042b32
Reviewed-on: https://go-review.googlesource.com/38085
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
POSIX Shell only supports = to compare variables inside '[' tests. But
this is Bash, where == is an alias for =. In practice they're the same,
but the current form is inconsisnent and breaks POSIX for no good
reason.
Change-Id: I38fa7a5a90658dc51acc2acd143049e510424ed8
Reviewed-on: https://go-review.googlesource.com/38031
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The fmtmode and fmtpkgpfx globals stand in the
way of making the compiler more concurrent (#15756).
This CL removes them.
The natural way to eliminate a global is to explicitly
thread it as a parameter through all function calls.
However, most of the functions in gc/fmt.go
get called indirectly, by way of fmt format strings,
so there's nowhere natural to add a parameter.
Since there are only a few fmtmode modes,
use named types to distinguish between modes.
For example, fmtNodeErr, fmtNodeDbg, and fmtNodeTypeId
are all gc.Node, but they print in different modes.
Varying the type allows us to thread mode through fmt.
Handle fmtpkgpfx by converting it to a printing mode,
FTypeIdName, and using the same type-based approach.
To avoid a loss of readability and danger of bugs
from introducing conversions at all call sites,
instead add a helper that systematically modifies the args.
The only remaining gc/fmt.go global is dumpdepth.
Since that is used for debugging only,
it that can be handled with a global mutex,
or some similarly basic, if inefficient, protection.
Passes toolstash -cmp. No compiler performance impact.
For future reference, other options for threading state
that were considered and rejected:
* Wrapping values in structs, such as:
type fmtNode struct {
n *Node
mode fmtMode
}
This reduces the proliferation of types, and supports
easily adding extra local parameters.
However, putting such a struct into an interface{} allocates.
This is unacceptable in this particular area of code.
* Passing state via precision, such as:
fmt.Fprintf("%*v", mode, n)
where mode is the state encoded as an integer.
This avoids extra allocations, but it is out of keeping
with the intended semantics of precision, and is less readable.
* Modify the fmt package to support setting/getting context
via fmt.State. Unavailable due to Go 1 compatibility,
and probably the wrong solution anyway.
* Give up on package fmt. This would be a huge readability
regression and cause high code churn.
* Attempt a de-novo rewrite that circumvents these problems.
Too high a risk of bugs, with insufficient reward for the effort,
particularly since long term plans call for elimination
of gc.Node.
Change-Id: Iea2440d5a34a938e64273707de27e3a897cb41d1
Reviewed-on: https://go-review.googlesource.com/38147
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
With this change, code like
h := sha1.New()
h.Write(buf)
sum := h.Sum()
gets compiled into static calls rather than
interface calls, because the compiler is able
to prove that 'h' is really a *sha1.digest.
The InterCall re-write rule hits a few dozen times
during make.bash, and hundreds of times during all.bash.
The most common pattern identified by the compiler
is a constructor like
func New() Interface { return &impl{...} }
where the constructor gets inlined into the caller,
and the result is used immediately. Examples include
{sha1,md5,crc32,crc64,...}.New, base64.NewEncoder,
base64.NewDecoder, errors.New, net.Pipe, and so on.
Some existing benchmarks that change on darwin/amd64:
Crc64/ISO4KB-8 2.67µs ± 1% 2.66µs ± 0% -0.36% (p=0.015 n=10+10)
Crc64/ISO1KB-8 694ns ± 0% 690ns ± 1% -0.59% (p=0.001 n=10+10)
Adler32KB-8 473ns ± 1% 471ns ± 0% -0.39% (p=0.010 n=10+9)
On architectures like amd64, the reduction in code size
appears to contribute more to benchmark improvements than just
removing the indirect call, since that branch gets predicted
accurately when called in a loop.
Updates #19361
Change-Id: I57d4dc21ef40a05ec0fbd55a9bb0eb74cdc67a3d
Reviewed-on: https://go-review.googlesource.com/38139
Run-TryBot: Philip Hofer <phofer@umich.edu>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Changes to ${GOARCH}Ops.go files were mechanically produced using
github.com/mdempsky/ssa-symops, a one-off tool that inserts
"SymEffect: X" elements by pattern matching against the Op names.
Change-Id: Ibf3e481ffd588647f2a31662d72114b740ccbfcf
Reviewed-on: https://go-review.googlesource.com/38084
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
To replace the progeffects tables for liveness analysis.
Change-Id: Idc4b990665cb0a9aa300d62cdf8ad12e51c5b991
Reviewed-on: https://go-review.googlesource.com/38083
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Bad pragmas should never make it to the backend.
I've confirmed manually that the error position is unchanged.
Updates #15756
Updates #19250
Change-Id: If14f7ce868334f809e337edc270a49680b26f48e
Reviewed-on: https://go-review.googlesource.com/38152
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Retry the test several times with increasingly long timeouts.
Fixes#19538 (hopefully)
Change-Id: Ia3bf2b63b4298a6ee1e4082e14d9bfd5922c293a
Reviewed-on: https://go-review.googlesource.com/38154
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
There were a surprising number of places
in the tree that used yyerror for failed internal
consistency checks. Switch them to Fatalf.
Updates #15756
Updates #19250
Change-Id: Ie4278148185795a28ff3c27dacffc211cda5bbdd
Reviewed-on: https://go-review.googlesource.com/38153
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
