Brad Fitzpatrick [Sun, 9 Oct 2016 17:20:39 +0000 (10:20 -0700)]
doc: update go1.8.txt using new tool
With help of a new interactive commit classifier tool (tool location
TBD, likely x/build/cmd/writenotes), classify all commits from go1.7
up to 56d35d4.
We can selectively cull this list later. When in doubt, I erred on the
side of inclusion for now.
Michael Munday [Fri, 7 Oct 2016 18:29:55 +0000 (14:29 -0400)]
cmd/{asm,compile}: replace TESTB op with CMPWconst on s390x
TESTB was implemented as AND $0xff, Rx, REGTMP. Unfortunately there
is no 3-operand AND-with-immediate instruction and so it was emulated
by the assembler using two instructions.
This CL uses CMPW instead of AND and also optimizes CMPW to use
the chi instruction where possible.
Overall this CL reduces the size of the .text section of the
bin/go binary by ~2%.
Keith Randall [Fri, 7 Oct 2016 17:08:10 +0000 (10:08 -0700)]
cmd/compile: use standard dom tree in nilcheckelim
No need to build a bespoke dom tree here when we might
have one cached already. The allocations for the dom tree
were also more expensive than they needed to be.
Currently these are labeled "MARK", which was accurate in the STW
collector, but these really indicate mark termination now, since
marking happens for the full duration of the concurrent GC. Re-label
them as "MARK TERMINATION" to clarify this.
cmd/trace: move process-wide GC events to their own row
Currently, the process-wide GC state is attributed to the P that
happened to perform the allocation that exceeded the GC trigger. This
is pretty arbitrary and makes it hard to see when GC is running since
the GC spans are intermingled with a lot of other trace noise.
The current display is particularly confusing because it creates three
sub-rows in the P row that can overlap each other. Usually a P has
just two sub-rows: one showing the current G and another showing that
G's activity. However, because GC is attributed to a proc, it winds up
as a third row that neither subsumes nor is subsumed by any other row.
This in turn screws up the trace's layout and results in overlapping
events.
Fix these problems by creating a new dedicated row like the existing
"Network" and "Timer" rows and displaying process-wide GC events in
this row. Mark termination and sweep events still appear in their
respective P rows because these are meaningfully attributed.
When GC is disabled, we set gcpercent to -1. However, we still use
gcpercent to compute several values, such as next_gc and gc_trigger.
These calculations are meaningless when gcpercent is -1 and result in
meaningless values. This is okay in a sense because we also never use
these values if gcpercent is -1, but they're confusing when exposed to
the user, for example via MemStats or the execution trace. It's
particularly unfortunate in the execution trace because it attempts to
plot the underflowed value of next_gc, which scales all useful
information in the heap row into oblivion.
Fix this by making next_gc ^0 when gcpercent < 0. This has the
advantage of being true in a way: next_gc is effectively infinite when
gcpercent < 0. We can also detect this special value when updating the
execution trace and report next_gc as 0 so it doesn't blow up the
display of the heap line.
Change-Id: I4f366e4451f8892a4908da7b2b6086bdc67ca9a9
Reviewed-on: https://go-review.googlesource.com/30016 Reviewed-by: Rick Hudson <rlh@golang.org>
Russ Cox [Thu, 6 Oct 2016 21:08:44 +0000 (17:08 -0400)]
fmt: document and adjust Scanf space handling to eliminate a few paradoxes
This CL makes minor adjustment to the handling of spaces and newlines
and then documents the result.
The semantic adjustment mainly concerns the handling of a run of
spaces following a newline in the format, like in "\n ".
Previously, that run of spaces was ignored entirely, leading to paradoxes
like the format "1 \n 2" not matching itself as input.
Now, spaces following a newline in the format match zero or more
spaces following the corresponding newline in the input.
The changes to the test suite show how minor the semantic adjustments are
and how they make the behavior more regular than previously.
This CL also updates the documentation to explain the handling of
spaces more precisely, incorporating the draft from CL 17723 but
describing the newly introduced behavior.
Fixes #13565.
Change-Id: I129666e9ba42de3c28b67f75cb47488e9a4c1867
Reviewed-on: https://go-review.googlesource.com/30611 Reviewed-by: Rob Pike <r@golang.org>
Russ Cox [Fri, 11 Dec 2015 02:43:51 +0000 (21:43 -0500)]
fmt: add tests showing current Scanf space handling
There are no semantic changes here, just tests to establish
the status quo. A followup CL will make some semantic changes,
the (limited) scope of which should be clear from the number of
tests that change.
Ian Lance Taylor [Thu, 6 Oct 2016 22:14:58 +0000 (15:14 -0700)]
runtime: fix sigset type for ppc64 big-endian GNU/Linux
On 64-bit big-endian GNU/Linux machines we need to treat sigset as a
single uint64, not as a pair of uint32 values. This fix was already made
for s390x, but not for ppc64 (which is big-endian--the little endian
version is known as ppc64le). So copy os_linux_390.x to
os_linux_be64.go, and use build constraints as needed.
Fixes #17361
Change-Id: Ia0eb18221a8f5056bf17675fcfeb010407a13fb0
Reviewed-on: https://go-review.googlesource.com/30602
Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Robert Griesemer [Wed, 5 Oct 2016 22:59:09 +0000 (15:59 -0700)]
spec: clarify acceptable indices in array/slice composite literals
This simply documents the status quo accepted by cmd/compile, gccgo,
and go/types. The new language matches the language used for indices
of index expressions for arrays and slices.
Fixes #16679.
Change-Id: I65447889fbda9d222f2a9e6c10334d1b38c555f0
Reviewed-on: https://go-review.googlesource.com/30474 Reviewed-by: Rob Pike <r@golang.org>
Richard Gibson [Mon, 28 Mar 2016 21:15:01 +0000 (17:15 -0400)]
encoding/json: explicitly document and test "-" key tag
Struct fields can be suppressed in JSON serialization by "-" tags, but
that doesn't preclude generation of "-" object keys.
Document and verify the mechanism for doing so.
Michael Munday [Tue, 4 Oct 2016 19:35:28 +0000 (15:35 -0400)]
cmd/{asm,compile}: add ANDW, ORW and XORW instructions to s390x
Adds the following instructions and uses them in the SSA backend:
- ANDW
- ORW
- XORW
The instruction encodings for 32-bit operations are typically shorter,
particularly when an immediate is used. For example, XORW $-1, R1
only requires one instruction, whereas XOR requires two.
Also removes some unused instructions (that were emulated):
Keith Randall [Wed, 5 Oct 2016 21:35:47 +0000 (14:35 -0700)]
cmd/compile: don't shuffle rematerializeable values around
Better to just rematerialize them when needed instead of
cross-register spilling or other techniques for keeping them in
registers.
This helps for amd64 code that does 1 << x. It is better to do
loop:
MOVQ $1, AX // materialize arg to SLLQ
SLLQ CX, AX
...
goto loop
than to do
MOVQ $1, AX // materialize outsize of loop
loop:
MOVQ AX, DX // save value that's about to be clobbered
SLLQ CX, AX
MOVQ DX, AX // move it back to the correct register
goto loop
Ian Lance Taylor [Wed, 5 Oct 2016 14:31:11 +0000 (07:31 -0700)]
runtime: add threadprof tag for test that starts busy thread
The CgoExternalThreadSIGPROF test starts a thread at constructor time
that does a busy loop. That can throw off some other tests. So only
build that code if testprogcgo is built with the tag threadprof, and
adjust the tests that use that code to pass that build tag.
This revealed that the CgoPprofThread test was not testing what it
should have, as it never actually started the cpuHog thread. It was
passing because of the busy loop thread. Fix it to start the thread as
intended.
Change-Id: I087a9e4fc734a86be16a287456441afac5676beb
Reviewed-on: https://go-review.googlesource.com/30362
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Larz Conwell [Sat, 12 Mar 2016 07:57:24 +0000 (02:57 -0500)]
go/doc: hide methods on locally-declared predeclared types
Currently if you declare a type overwriting a predeclared type
and export methods on it they will be exposed in godoc, even
though the type itself is not exported. This corrects that
by making all methods on these types hidden, since that's
the expected output.
cmd/go: note when some Go files were ignored on no-Go-files errors
It is pretty confusing when there are Go files ignored for mismatching
build tags and similar and we output "no buildable Go files" without
giving any other information about some Go files have been ignored.
Dmitriy Dudkin [Thu, 25 Feb 2016 02:00:01 +0000 (04:00 +0200)]
cmd/go: fix go get -u wildcard corner case
Suppose you have already downloaded "foo.bar/baz", where the repo
is for all of foo.bar/, and you then "go get -u foo.bar/...".
The command-line wildcard expands to foo.bar/baz,
and go get updates the foo.bar/ repo.
Suppose that the repo update brought in foo.bar/quux,
though, which depends on other.site/bar.
Download does not consider foo.bar/quux, since it's
only looking at foo.bar/baz, so it didn't download other.site/bar.
After the download, we call importPaths(args) to decide what to install.
That call was reevaluating the original wildcard with the new repo
and matching foo.bar/quux, which was missing its dependency
other.site/bar, causing a build failure.
The fix in this CL is to remember the pre-download expansion
of the argument list and pass it to the installer. Then only the things
we tried to download get installed.
The case where foo.bar/ is not even checked out yet continues to work,
because in that case we leave the wildcard in place, and download
reevaluates it during the download.
The fix in this CL may not be the right long-term fix, but it is at least a fix.
It may be that download should be passed all the original wildcards
so that it can reexpand them as new code is downloaded, ideally reaching
a fixed point. That can be left for another day.
In short:
- The problem is that the "install" half of "go get" was trying to install
more than the "download" half was properly downloading.
- The fix in this CL is to install just what was downloaded (install less).
- It may be that a future CL should instead download what will be installed (download more).
Quentin Smith [Wed, 5 Oct 2016 22:04:54 +0000 (18:04 -0400)]
crypto/x509: support RHEL 7 cert bundle
RHEL 7 introduces a new tool, update-ca-trust(8), which places the
certificate bundle in a new location. Add this path to the list of
locations that are searched for the certificate bundle.
Reasons:
This CL was causing failures on a large regression test that we run
within Google. The issues arises from two bugs in the CL:
* The CL dropped support for ';' as a delimiter (see https://golang.org/issue/2210)
* The handling of an empty string caused an empty record to be added when
no record was added (see https://golang.org/cl/30454 for my attempted fix)
The logic being added is essentially a variation of url.ParseQuery,
but altered to accept an io.Reader instead of a string.
Since it is duplicated (but modified) logic, there needs to be good
tests to ensure that it's implementation doesn't drift in functionality
from url.ParseQuery. Fixing the above issues and adding the associated
regression tests leads to >100 lines of codes.
For a 4% reduction in CPU time, I think this complexity and duplicated
logic is not worth the effort.
As such, I am abandoning my efforts to fix the existing issues and
believe that reverting CL/20301 is the better course of action.
Quentin Smith [Wed, 5 Oct 2016 18:37:25 +0000 (14:37 -0400)]
syscall: relax TestUnshare
Fixes #17224.
Some systems have more than just "lo" in a fresh network namespace, due
to IPv6. Instead of testing for exactly 3 lines of output (implying 1
interface), just test to make sure that the unshare call resulted in
fewer interfaces than before. This should still verify that unshare did
something.
Russ Cox [Wed, 5 Oct 2016 15:26:04 +0000 (11:26 -0400)]
encoding/json: use standard ES6 formatting for numbers during marshal
Change float32/float64 formatting to use non-exponential form
for a slightly wider range, to more closely match ES6 JSON.stringify
and other JSON generators.
Most notably:
1e20 now formats as 100000000000000000000 (previously 1e+20)
1e-6 now formats as 0.000001 (previously 1e-06)
1e-7 now formats as 1e-7 (previously 1e-07)
This also brings the int64 and float64 formatting in line with each other,
for all shared representable values. For example both int64(1234567)
and float64(1234567) now format as "1234567", where before the
float64 formatted as "1.234567e+06".
The only variation now compared to ES6 JSON.stringify is that
Go continues to encode negative zero as "-0", not "0", so that
the value continues to be preserved during JSON round trips.
Cherry Zhang [Sun, 2 Oct 2016 21:10:13 +0000 (17:10 -0400)]
runtime, cmd/internal/obj: get rid of rewindmorestack
In the function prologue, we emit a jump to the beginning of
the function immediately after calling morestack. And in the
runtime stack growing code, it decodes and emulates that jump.
This emulation was necessary before we had per-PC SP deltas,
since the traceback code assumed that the frame size was fixed
for the whole function, except on the first instruction where
it was 0. Since we now have per-PC SP deltas and PCDATA, we
can correctly record that the frame size is 0. This makes the
emulation unnecessary.
This may be helpful for registerized calling convention, where
there may be unspills of arguments after calling morestack. It
also simplifies the runtime.
Change-Id: I7ebee31eaee81795445b33f521ab6a79624c4ceb
Reviewed-on: https://go-review.googlesource.com/30138 Reviewed-by: David Chase <drchase@google.com>
Keith Randall [Tue, 4 Oct 2016 21:35:45 +0000 (14:35 -0700)]
cmd/compile: make CSE faster
To refine a set of possibly equivalent values, the old CSE algorithm
picked one value, compared it against all the others, and made two sets
out of the results (the values that match the picked value and the
values that didn't). Unfortunately, this leads to O(n^2) behavior. The
picked value ends up being equal to no other values, we make size 1 and
size n-1 sets, and then recurse on the size n-1 set.
Instead, sort the set by the equivalence classes of its arguments. Then
we just look for spots in the sorted list where the equivalence classes
of the arguments change. This lets us do a multi-way split for O(n lg
n) time.
This change makes cmpDepth unnecessary.
The refinement portion used to call the type comparator. That is
unnecessary as the type was already part of the initial partition.
Lowers time of 16361 from 8 sec to 3 sec.
Lowers time of 15112 from 282 sec to 20 sec. That's kind of unfair, as
CL 30257 changed it from 21 sec to 282 sec. But that CL fixed other bad
compile times (issue #17127) by large factors, so net still a big win.
For a simple application that I wrote, which reads in a CSV file (via
ReadAll) and outputs the number of rows read (15857625 rows), this change
reduces the total time on my notebook from ~58 seconds to ~48 seconds.
This reduces time and allocations (bytes) each by ~6% for a real world
CSV file at work (~230000 rows, 13 colums).
Michael Munday [Fri, 30 Sep 2016 18:20:42 +0000 (14:20 -0400)]
crypto/{aes,cipher}: add optimized implementation of AES-GCM for s390x
Also adds two tests: one to exercise the counter incrementing code
and one which checks the output of the optimized implementation
against that of the generic implementation for large/unaligned data
sizes.
Uses the KIMD instruction for GHASH and the KMCTR instruction for AES
in counter mode.
Brad Fitzpatrick [Wed, 5 Oct 2016 04:35:59 +0000 (04:35 +0000)]
sort: fix a slice benchmark not using the stable variant, add another
Change-Id: I9783d8023d453a72c4605a308064bef98168bcb8
Reviewed-on: https://go-review.googlesource.com/30360 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Ian Lance Taylor [Mon, 3 Oct 2016 23:58:34 +0000 (16:58 -0700)]
runtime: don't call cgocallback from signal handler
Calling cgocallback from a signal handler can fail when using the race
detector. Calling cgocallback will lead to a call to newextram which
will call oneNewExtraM which will call racegostart. The racegostart
function will set up some race detector data structures, and doing that
will sometimes call the C memory allocator. If we are running the signal
handler from a signal that interrupted the C memory allocator, we will
crash or hang.
Instead, change the signal handler code to call needm and dropm. The
needm function will grab allocated m and g structures and initialize the
g to use the current stack--the signal stack. That is all we need to
safely call code that allocates memory and checks whether it needs to
split the stack. This may temporarily leave us with no m available to
run a cgo callback, but that is OK in this case since the code we call
will quickly either crash or call dropm to return the m.
Implementing this required changing some of the setSignalstackSP
functions to avoid a write barrier. These functions never need a write
barrier but in some cases generated one anyhow because on some systems
the ss_sp field is a pointer.
Change-Id: I3893f47c3a66278f85eab7f94c1ab11d4f3be133
Reviewed-on: https://go-review.googlesource.com/30218
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Jeff R. Allen [Sat, 5 Dec 2015 15:06:05 +0000 (21:06 +0600)]
image/gif: check handling of truncated GIF files
All the prefixes of the testGIF produce errors today,
but they differ wildly in which errors: some are io.EOF,
others are io.ErrUnexpectedEOF, and others are gif-specific.
Make them all gif-specific to explain context, and make
any complaining about EOF be sure to mention the EOF
is unexpected.
Joe Tsai [Wed, 3 Aug 2016 07:31:17 +0000 (00:31 -0700)]
cmd/doc: ensure summaries truly are only one line
The documentation for doc says:
> Doc prints the documentation comments associated with the item identified by its
> arguments (a package, const, func, type, var, or method) followed by a one-line
> summary of each of the first-level items "under" that item (package-level
> declarations for a package, methods for a type, etc.).
Certain variables (and constants, functions, and types) have value specifications
that are multiple lines long. Prior to this change, doc would print out all of the
lines necessary to display the value. This is inconsistent with the documented
behavior, which guarantees a one-line summary for all first-level items.
We fix this here by writing a general oneLineNode method that always returns
a one-line summary (guaranteed!) of any input node.
Packages like image/color/palette and unicode now become much
more readable since large slices are now a single line.
$ go doc image/color/palette
<<<
// Before:
var Plan9 = []color.Color{
color.RGBA{0x00, 0x00, 0x00, 0xff},
color.RGBA{0x00, 0x00, 0x44, 0xff},
color.RGBA{0x00, 0x00, 0x88, 0xff},
... // Hundreds of more lines!
}
var WebSafe = []color.Color{
color.RGBA{0x00, 0x00, 0x00, 0xff},
color.RGBA{0x00, 0x00, 0x33, 0xff},
color.RGBA{0x00, 0x00, 0x66, 0xff},
... // Hundreds of more lines!
}
// After:
var Plan9 = []color.Color{ ... }
var WebSafe = []color.Color{ ... }
>>>
In order to test this, I ran `go doc` and `go doc -u` on all of the
standard library packages and diff'd the output with and without the
change to ensure that all differences were intended.
Fixes #13072
Change-Id: Ida10b7796b7e4e174a929b55c60813a9eb7158fe
Reviewed-on: https://go-review.googlesource.com/25420
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rob Pike <r@golang.org>
Robert Griesemer [Mon, 3 Oct 2016 20:28:25 +0000 (13:28 -0700)]
go/ast, go/parser: parse alias declarations
For now, we also accept "type p = p.T" (using = instead of =>, for
type aliases only), so we can experiment with an approach that only
uses type aliases. This concession is implemened in the parser.
For #16339
Change-Id: I88b5522a8b6cfc2e97ca146ede8b32af340220f8
Reviewed-on: https://go-review.googlesource.com/30211 Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Carl Mastrangelo [Mon, 3 Oct 2016 19:45:12 +0000 (12:45 -0700)]
runtime: make append only clear uncopied memory
Also add a benchmark that shows off the new behavior. The
existing benchmarks reuse the same slice, and thus don't ever have
to clear memory. Running the Append|Grow benchmarks in runtime:
Change-Id: I69a8afbd942c787c591d95b9d9439bd6db4d1e49
Reviewed-on: https://go-review.googlesource.com/30192 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Quentin Renard [Sun, 6 Mar 2016 16:27:50 +0000 (17:27 +0100)]
net/http: improve performance for parsePostForm
Remove the use of io.ReadAll in http.parsePostForm to avoid converting
the whole input from []byte to string and not performing well
space-allocated-wise.
Instead a new function called parsePostFormURLEncoded is used and is
fed directly an io.Reader that is parsed using a bufio.Reader.
Benchmark:
name old time/op new time/op delta
PostQuery-4 2.90µs ± 6% 2.82µs ± 4% ~ (p=0.094 n=9+9)
name old alloc/op new alloc/op delta
PostQuery-4 1.05kB ± 0% 0.90kB ± 0% -14.49% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
PostQuery-4 6.00 ± 0% 7.00 ± 0% +16.67% (p=0.000 n=10+10)
Matthew Dempsky [Mon, 3 Oct 2016 23:09:13 +0000 (16:09 -0700)]
cmd/compile: cleanup artifacts from previous CL
Does not pass toolstash, but only because it causes ATYPE instructions
to be emitted in a different order, and it avoids emitting type
metadata for unused variables.
Robert Griesemer [Fri, 3 Jun 2016 20:21:55 +0000 (13:21 -0700)]
spec: ignore struct tags when converting structs
This is a backwards-compatible language change.
Per the proposal (#16085), the rules for conversions are relaxed
such that struct tags in any of the structs involved in the conversion
are ignored (recursively).
Because this is loosening the existing rules, code that compiled so
far will continue to compile.
Dhananjay Nakrani [Sun, 2 Oct 2016 01:01:30 +0000 (18:01 -0700)]
cmd/cover: Fix compiler directives handling.
Currently, it separates comments from rest of the AST. This causes problems when
long counter increment statements are added before compiler directives.
See Issue #17315.
This change moves comments handling into AST Visitor so that when printer prints
code from AST, position of compiler directives relative to the associated function
is preserved.
Nick Craig-Wood [Tue, 4 Oct 2016 13:04:18 +0000 (14:04 +0100)]
runtime: correct function name in throw message
Change-Id: I8fd271066925734c3f7196f64db04f27c4ce27cb
Reviewed-on: https://go-review.googlesource.com/30274 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Filippo Valsorda [Wed, 23 Dec 2015 02:03:44 +0000 (02:03 +0000)]
crypto/tls: implement countermeasures against CBC padding oracles
The aim is to make the decrypt() timing profile constant, irrespective of
the CBC padding length or correctness. The old algorithm, on valid padding,
would only MAC bytes up to the padding length threshold, making CBC
ciphersuites vulnerable to plaintext recovery attacks as presented in the
"Lucky Thirteen" paper.
The new algorithm Write()s to the MAC all supposed payload, performs a
constant time Sum()---which required implementing a constant time Sum() in
crypto/sha1, see the "Lucky Microseconds" paper---and then Write()s the rest
of the data. This is performed whether the padding is good or not.
This should have no explicit secret-dependent timings, but it does NOT
attempt to normalize memory accesses to prevent cache timing leaks.
Change-Id: Id838fcc234e71f735bb2609073f4c2214b48a970
Reviewed-on: https://go-review.googlesource.com/29891 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Mikio Hara [Sat, 1 Oct 2016 10:20:32 +0000 (19:20 +0900)]
syscall: fix Send{msg,msgN}, Recvmsg and control message handling on solaris
This change switches the use of socket implementation from the
conventional SUS-based one to the latest POSIX-based one to make
socket control message work correctly on Solaris.
It looks like those two implementations, Socket over TLI/XTI and
Socket, have different semantics in details but it wouldn't hurt
the existing applications because the exposed syscall API doesn't
support socket properties related to such a protocol independent
application framework.
Fixes #7402.
Change-Id: I45a4e782d606bfbebe1404086c50a8c69af53461
Reviewed-on: https://go-review.googlesource.com/30171 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Michael Munday [Fri, 30 Sep 2016 16:04:46 +0000 (12:04 -0400)]
cmd/compile: remove unnecessary OpSB checks in S390X.rules
Reversed, indexed and multi-register stores/loads cannot accept SB
inputs. Therefore if one of these Ops is an input to a rule any
pointer that is an argument to that Op cannot be OpSB.
Change-Id: Ib8048362d1c6277122afec0d13a1c905290d69cb
Reviewed-on: https://go-review.googlesource.com/30131
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
In particular, it wasn't obvious that some values are special (unless
you also found those special values), so document that it isn't
necessarily a hash value.