This is a redo of CL 41076 backported to the 1.8 release branch.
There were major conflicts, so I had to basically rewrite it again
from scratch. The way Progs are allocated changed. Liveness analysis
and Prog generation got reordered. Liveness analysis changed from
running on gc.BasicBlock to ssa.Block. All that makes the logic quite
a bit different.
Please review carefully.
From CL 41076:
At VARKILLs, zero a variable if it is ambiguously live.
After the VARKILL anything this variable references
might be collected. If it were to become live again later,
the GC will see references to already-collected objects.
We don't know a variable is ambiguously live until very
late in compilation (after lowering, register allocation, ...),
so it is hard to generate the code in an arch-independent way.
We also have to be careful not to clobber any registers.
Fortunately, this almost never happens so performance is ~irrelevant.
There are only 2 instances where this triggers in the stdlib.
Fixes#20029
Change-Id: Ibb757eec58ee07f40df5e561b19d315684dc4bda
Reviewed-on: https://go-review.googlesource.com/43998
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Cherry-pick of CL 43294.
Tuple ops are weird. They are essentially a pair of ops,
one which consumes a mem and one which generates a mem (the Select1).
The schedule pass didn't handle these quite right.
Fix the scheduler to include both parts of the paired op in
the store chain. That makes sure that loads are correctly ordered
with respect to the first of the pair.
Add a check for the ssacheck builder, that there is only one
live store at a time. I thought we already had such a check, but
apparently not...
Fixes#20335
Change-Id: I59eb3446a329100af38d22820b1ca2190ca46a78
Reviewed-on: https://go-review.googlesource.com/43411
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The uintptr-typed Data field in reflect.SliceHeader and
reflect.StringHeader needs special treatment because it is
really a pointer. Add the special treatment in walk for
bug #19168 to escape analysis.
Includes extra debugging that was helpful.
Fixes#19743.
Change-Id: I6dab5002f0d436c3b2a7cdc0156e4fc48a43d6fe
Reviewed-on: https://go-review.googlesource.com/39616
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Fixes#19168.
(*state).insertWBstore needed to be tweaked for backporting so that
store reflect.{Slice,String}Header.Data stores still fallthrough and
end the SSA block. This wasn't necessary at master because of CL
36834.
Change-Id: I3f4fcc0b189c53819ac29ef8de86fdad76a17488
Reviewed-on: https://go-review.googlesource.com/39615
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Austin Clements <austin@google.com>
The loop-A-encloses-loop-C code did not properly handle the
case where really C was already known to be enclosed by B,
and A was nearest-outer to B, not C.
Fixes#19217.
Change-Id: I755dd768e823cb707abdc5302fed39c11cdb34d4
Reviewed-on: https://go-review.googlesource.com/39596
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Added a flag to generic and various architectures' atomic
operations that are judged to have observable side effects
and thus cannot be dead-code-eliminated.
Test requires GOMAXPROCS > 1 without preemption in loop.
Fixes#19182.
Change-Id: Id2230031abd2cca0bbb32fd68fc8a58fb912070f
Reviewed-on: https://go-review.googlesource.com/39595
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Scheduling values after calls to selectrecv,
will cause them to be executed multiple times, due to runtime.selectgo
jumping to the next instruction in the selectrecv basic block.
Prevent this by scheduling calls to selectrecv as late as possible
Fixes#19201
Change-Id: I6415792e2c465dc6d9bd6583ba1e54b107bcf5cc
Reviewed-on: https://go-review.googlesource.com/38587
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The rules for folding addresses into load/stores checks sym1 is
not on stack (because the stack offset is not known at that point).
But sym1 could be nil, which invalidates the check. Check merged
sym instead.
Fixes#19137.
Change-Id: I8574da22ced1216bb5850403d8f08ec60a8d1005
Reviewed-on: https://go-review.googlesource.com/37145
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
(cherry picked from commit 3557d54609)
Reviewed-on: https://go-review.googlesource.com/37214
The compiler did not emit write barrier for assigning global with
struct literal, like global = T{} where T contains pointer.
The relevant code path is:
walkexpr OAS var_ OSTRUCTLIT
oaslit
anylit OSTRUCTLIT
walkexpr OAS var_ nil
return without adding write barrier
return true
break (without adding write barrier)
This CL makes oaslit not apply to globals. See also CL
https://go-review.googlesource.com/c/36355/ for an alternative
fix.
The downside of this is that it generates static data for zeroing
struct now. Also this only covers global. If there is any lurking
bug with implicit zeroing other than globals, this doesn't fix.
Fixes#18956.
Change-Id: Ibcd27e4fae3aa38390ffa94a32a9dd7a802e4b37
Reviewed-on: https://go-review.googlesource.com/36410
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
(cherry picked from commit 160914e33c)
Reviewed-on: https://go-review.googlesource.com/36531
For code such as
if a := 10 { ...
the 1.7 compiler reported
a := 10 used as value
while the 1.8 compiler reported
invalid condition, tag, or type switch guard
Changed the error message to match the 1.7 compiler.
Fixes#18915.
Change-Id: I01308862e461922e717f9f8295a9db53d5a914eb
Reviewed-on: https://go-review.googlesource.com/36470
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-on: https://go-review.googlesource.com/36422
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
This CL fixes two issues:
1. Load ops were initially always lowered to unsigned loads, even
for signed types. This was fine by itself however LoadReg ops
(used to re-load spilled values) were lowered to signed loads
for signed types. This meant that spills could invalidate
optimizations that assumed the original unsigned load.
2. Types were not always being maintained correctly through rules
designed to eliminate unnecessary zero and sign extensions.
Updates #18906 and fixes#18958 (backport of CL 36256 to 1.8).
Change-Id: Id44953b0f644cad047e8474edbd24e8a344ca9a7
Reviewed-on: https://go-review.googlesource.com/36350
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
When nilcheck runs, the values in a block are not in any particular
order. So any facts derived from examining the blocks shouldn't be
used until we reach the next block.
This is suboptimal as it won't eliminate nil checks within a block.
But it's probably a better fix for now as it is a much smaller change
than other strategies for fixing this bug.
nilptr3.go changes are mostly because for this pattern:
_ = *p
_ = *p
either nil check is fine to keep, and this CL changes which one
the compiler tends to keep.
There are a few regressions from code like this:
_ = *p
f()
_ = *p
For this pattern, after this CL we issue 2 nil checks instead of one.
(For the curious, this happens because intra-block nil check
elimination now falls to CSE, not nilcheck proper. The former
pattern has two nil checks with the same store argument. The latter
pattern has two nil checks with different store arguments.)
Fixes#18725
Change-Id: I3721b494c8bc9ba1142dc5c4361ea55c66920ac8
Reviewed-on: https://go-review.googlesource.com/35485
Reviewed-by: Cherry Zhang <cherryyz@google.com>
The test is inherently racy and vulnerable to starvation,
and within all.bash on some platforms that means it flakes.
Test is kept because it can be useful standalone to verify
behavior of GOEXPERIMENT=preeemptibleloops, and there is
likely to be further development of this feature in the
future.
There's also some question as to why it is flaking, because
though technically this is permitted, it's very odd in this
simple case.
Fixes#18589.
Change-Id: Ia0dd9037285c4a03122da4012c96981c9cc43b60
Reviewed-on: https://go-review.googlesource.com/35051
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Loop breaking with a counter. Benchmarked (see comments),
eyeball checked for sanity on popular loops. This code
ought to handle loops in general, and properly inserts phi
functions in cases where the earlier version might not have.
Includes test, plus modifications to test/run.go to deal with
timeout and killing looping test. Tests broken by the addition
of extra code (branch frequency and live vars) for added
checks turn the check insertion off.
If GOEXPERIMENT=preemptibleloops, the compiler inserts reschedule
checks on every backedge of every reducible loop. Alternately,
specifying GO_GCFLAGS=-d=ssa/insert_resched_checks/on will
enable it for a single compilation, but because the core Go
libraries contain some loops that may run long, this is less
likely to have the desired effect.
This is intended as a tool to help in the study and diagnosis
of GC and other latency problems, now that goal STW GC latency
is on the order of 100 microseconds or less.
Updates #17831.
Updates #10958.
Change-Id: I6206c163a5b0248e3f21eb4fc65f73a179e1f639
Reviewed-on: https://go-review.googlesource.com/33910
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
CALLPART of STRUCTLIT did not check for incomplete initialization
of struct; modify PTRLIT treatment to force zeroing.
Test for structlit, believe this might have also failed for
arraylit.
Fixes#18410.
Change-Id: I511abf8ef850e300996d40568944665714efe1fc
Reviewed-on: https://go-review.googlesource.com/34622
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Fixes#18392.
Avoid nil dereferencing n.Right when dealing with non-existent
self referenced interface methods e.g.
type A interface{
Fn(A.Fn)
}
Instead, infer the symbol name from n.Sym itself.
Change-Id: I60d5f8988e7318693e5c8da031285d8d7347b771
Reviewed-on: https://go-review.googlesource.com/34817
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Fixes#6772.
Lock-in test for invalid range loop: repeated variables in range declaration.
Change-Id: I37dd8b1cd7279abe7810deaf8a5d485c5c3b73ca
Reviewed-on: https://go-review.googlesource.com/34714
Reviewed-by: Keith Randall <khr@golang.org>
Fixes#5790.
Fixes#18421.
* Lock in _ = x1/x2 divide by zero runtime panics since
it is actually evaluated and not discarded as in previous
versions before Go1.8.
* Update a test that was skipping over zerodivide tests
that expected runtime panics, enabling us to check for
the expected panics.
Change-Id: I0af0a6ecc19345fa9763ab2e35b275fb2d9d0194
Reviewed-on: https://go-review.googlesource.com/34712
Reviewed-by: Keith Randall <khr@golang.org>
Change-Id: I00c97c36e8fdc79582eaed21877e4c8f44568666
Reviewed-on: https://go-review.googlesource.com/34316
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This was a regression from 1.7. See the issue for details.
Fixes#18149.
Change-Id: Ic8f5a35d14edf9254b1275400316cff7aff32a27
Reviewed-on: https://go-review.googlesource.com/33799
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This fixes a bug in -l=3 or higher.
To inline a variadic function, the compiler generates code that constructs
a slice of arguments for the variadic parameter. Consider the function
func Foo(xs ...string)
and the call Foo("hello", "world"). To inline the call to Foo, the
compiler used to generate
xs := [2]string{"hello", "world"}[:]
which doesn't type check:
invalid operation [2]string literal[:] (slice of unaddressable value).
Now, the compiler generates
xs := []string{"hello", "world"}
which does type check.
Fixes#18116.
Change-Id: I0ee531ef2e6cc276db6fb12602b25a46d6d5db21
Reviewed-on: https://go-review.googlesource.com/33671
Reviewed-by: Keith Randall <khr@golang.org>
It was supposed to be testing SSA, not amd64.
For #18024
Change-Id: Ibe65d7eb6bed9bc4b3eda68e1eaec5fa39fe8f76
Reviewed-on: https://go-review.googlesource.com/33491
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
The table of rewrites in ssa/cse is not sized appropriately for
ssa IDs that are created during copying of selects into new blocks.
Fixes#17918
Change-Id: I65fe86c6aab5efa679aa473aadc4ee6ea882cd41
Reviewed-on: https://go-review.googlesource.com/33240
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The tree is inconsistent about single l vs double l in those
words in documentation, test messages, and one error value text.
$ git grep -E '[Mm]arshall(|s|er|ers|ed|ing)' | wc -l
42
$ git grep -E '[Mm]arshal(|s|er|ers|ed|ing)' | wc -l
1694
Make it consistently a single l, per earlier decisions. This means
contributors won't be confused by misleading precedence, and it helps
consistency.
Change the spelling in one error value text in newRawAttributes of
crypto/x509 package to be consistent.
This change was generated with:
perl -i -npe 's,([Mm]arshal)l(|s|er|ers|ed|ing),$1$2,' $(git grep -l -E '[Mm]arshall' | grep -v AUTHORS | grep -v CONTRIBUTORS)
Updates #12431.
Follows https://golang.org/cl/14150.
Change-Id: I85d28a2d7692862ccb02d6a09f5d18538b6049a2
Reviewed-on: https://go-review.googlesource.com/33017
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
ppc64le supports both internal and external linking so I don't
think there is any reason for it to skip this test.
Change-Id: I05c80cc25909c0364f0a1fb7d20766b011ea1ebb
Reviewed-on: https://go-review.googlesource.com/32854
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reason: Decision to back out current alias implementation.
Leaving import/export related code in place for now.
For #16339.
TBR=mdempsky
Change-Id: Ib0897cab2c1c3dc8a541f2efb9893271b0b0efe2
Reviewed-on: https://go-review.googlesource.com/32757
Reviewed-by: Robert Griesemer <gri@golang.org>
Use a separate symbol for reflect metadata for types with Noalg set.
Fixes#17752.
Change-Id: Icb6cade7e3004fc4108f67df61105dc4085cd7e2
Reviewed-on: https://go-review.googlesource.com/32679
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
when compiling f(a, b, c), we do something like:
*(SP+0) = eval(a)
*(SP+8) = eval(b)
*(SP+16) = eval(c)
call f
If one of those evaluations is later determined to unconditionally panic
(say eval(b) in this example), then the call is deadcode eliminated. But
any previous argument write (*(SP+0)=... here) is still around. Becuase
we only compute the size of the outarg area for calls which are still
around at the end of optimization, the space needed for *(SP+0)=v is not
accounted for and thus the outarg area may be too small.
The fix is to make sure that we evaluate any potentially panicing
operation before we write any of the args to the stack. It turns out
that fix is pretty easy, as we already have such a mechanism available
for function args. We just need to extend it to possibly panicing args
as well.
The resulting code (if b and c can panic, but a can't) is:
tmpb = eval(b)
*(SP+16) = eval(c)
*(SP+0) = eval(a)
*(SP+8) = tmpb
call f
This change tickled a bug in how we find the arguments for intrinsic
calls, so that latent bug is fixed up as well.
Update #16760.
Change-Id: I0bf5edf370220f82bc036cf2085ecc24f356d166
Reviewed-on: https://go-review.googlesource.com/32551
Reviewed-by: Cherry Zhang <cherryyz@google.com>
The code to do the conversion is smaller than the
call to the runtime.
The 1-result asserts need to call panic if they fail, but that
code is out of line.
The only conversions left in the runtime are those which
might allocate and those which might need to generate an itab.
Given the following types:
type E interface{}
type I interface { foo() }
type I2 iterface { foo(); bar() }
type Big [10]int
func (b Big) foo() { ... }
This CL inlines the following conversions:
was assertE2T
var e E = ...
b := i.(Big)
was assertE2T2
var e E = ...
b, ok := i.(Big)
was assertI2T
var i I = ...
b := i.(Big)
was assertI2T2
var i I = ...
b, ok := i.(Big)
was assertI2E
var i I = ...
e := i.(E)
was assertI2E2
var i I = ...
e, ok := i.(E)
These are the remaining runtime calls:
convT2E:
var b Big = ...
var e E = b
convT2I:
var b Big = ...
var i I = b
convI2I:
var i2 I2 = ...
var i I = i2
assertE2I:
var e E = ...
i := e.(I)
assertE2I2:
var e E = ...
i, ok := e.(I)
assertI2I:
var i I = ...
i2 := i.(I2)
assertI2I2:
var i I = ...
i2, ok := i.(I2)
Fixes#17405Fixes#8422
Change-Id: Ida2367bf8ce3cd2c6bb599a1814f1d275afabe21
Reviewed-on: https://go-review.googlesource.com/32313
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
We generate an OpKeepAlive for the idata portion of the interface
for a runtime.KeepAlive call. But given such an op, we need to keep
the entire containing variable alive, not just the range that was
passed to the OpKeepAlive operation.
Fixes#17710
Change-Id: I90de66ec8065e22fb09bcf9722999ddda289ae6e
Reviewed-on: https://go-review.googlesource.com/32477
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
typecheckcomplit nils out node's type, upon finding new errors.
This hides new errors in children's node as well as the type info
of current node. This change fixes that.
Fixes#17645.
Change-Id: Ib473291f31c7e8fa0307cb1d494e0c112ddd3583
Reviewed-on: https://go-review.googlesource.com/32324
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Keith Randall
Todd Neal
David Chase
Matthew Dempsky
Josh Bleecher Snyder
Quentin Smith
Ilya Tocar
Cherry Zhang
Robert Griesemer
Michael Munday
Emmanuel Odeke
Vladimir Stefanovic
Ian Lance Taylor
Brad Fitzpatrick
David Lazar
Philip Hofer
Dmitri Shuralyov
Dhananjay Nakrani