Commit graph

54 commits

Author SHA1 Message Date
Matthew Dempsky
ca2f85fd3f cmd/compile: add indexed export format
This CL introduces a new indexed data format for package export
data. This improves on the previous (sequential) binary format by
allowing the compiler to selectively (and lazily) load only the data
that's actually needed for compilation.

In large Go projects, the package export data can become very large
due to transitive type declaration dependencies and inline
function/method bodies. By lazily loading these declarations and
bodies as needed, we avoid wasting time and memory processing
unnecessary and/or redundant data.

In the benchmarks below, "old" is -iexport=false and "new" is
-iexport=true. The suffixes indicate the compiler concurrency (-c) and
inlining (-l) settings used for the build (using -gcflags=all=-foo).
Benchmarks were run on an HP Z620.

Juju is "go build -a github.com/juju/juju/cmd/...":

name          old real-time/op  new real-time/op  delta
Juju/c=1/l=0        44.0s ± 1%        38.7s ± 9%  -11.97%  (p=0.001 n=7+7)
Juju/c=1/l=4        53.7s ± 3%        45.3s ± 4%  -15.53%  (p=0.001 n=7+7)
Juju/c=4/l=0        39.7s ± 8%        32.0s ± 4%  -19.38%  (p=0.001 n=7+7)
Juju/c=4/l=4        46.3s ± 4%        38.0s ± 4%  -18.06%  (p=0.001 n=7+7)

name          old user-time/op  new user-time/op  delta
Juju/c=1/l=0         371s ± 1%         300s ± 0%  -19.07%  (p=0.001 n=7+6)
Juju/c=1/l=4         482s ± 0%         374s ± 1%  -22.37%  (p=0.001 n=7+7)
Juju/c=4/l=0         410s ± 1%         340s ± 1%  -17.19%  (p=0.001 n=7+7)
Juju/c=4/l=4         532s ± 1%         424s ± 1%  -20.26%  (p=0.001 n=7+7)

name          old sys-time/op   new sys-time/op   delta
Juju/c=1/l=0        33.4s ± 1%        28.4s ± 2%  -15.02%  (p=0.001 n=7+7)
Juju/c=1/l=4        40.7s ± 2%        32.8s ± 3%  -19.51%  (p=0.001 n=7+7)
Juju/c=4/l=0        39.8s ± 2%        34.4s ± 2%  -13.74%  (p=0.001 n=7+7)
Juju/c=4/l=4        48.4s ± 2%        40.4s ± 2%  -16.50%  (p=0.001 n=7+7)

Kubelet is "go build -a k8s.io/kubernetes/cmd/kubelet":

name             old real-time/op  new real-time/op  delta
Kubelet/c=1/l=0        42.0s ± 1%        34.8s ± 1%  -17.27%  (p=0.008 n=5+5)
Kubelet/c=1/l=4        55.4s ± 3%        45.4s ± 3%  -18.06%  (p=0.002 n=6+6)
Kubelet/c=4/l=0        37.4s ± 3%        29.9s ± 1%  -20.25%  (p=0.004 n=6+5)
Kubelet/c=4/l=4        48.1s ± 2%        39.0s ± 5%  -18.93%  (p=0.002 n=6+6)

name             old user-time/op  new user-time/op  delta
Kubelet/c=1/l=0         291s ± 1%         233s ± 1%  -19.96%  (p=0.002 n=6+6)
Kubelet/c=1/l=4         385s ± 1%         298s ± 1%  -22.51%  (p=0.002 n=6+6)
Kubelet/c=4/l=0         325s ± 0%         268s ± 1%  -17.48%  (p=0.004 n=5+6)
Kubelet/c=4/l=4         429s ± 1%         343s ± 1%  -20.08%  (p=0.002 n=6+6)

name             old sys-time/op   new sys-time/op   delta
Kubelet/c=1/l=0        25.1s ± 2%        20.9s ± 4%  -16.69%  (p=0.002 n=6+6)
Kubelet/c=1/l=4        31.2s ± 3%        24.4s ± 0%  -21.67%  (p=0.010 n=6+4)
Kubelet/c=4/l=0        30.2s ± 2%        25.6s ± 1%  -15.34%  (p=0.002 n=6+6)
Kubelet/c=4/l=4        37.3s ± 1%        30.9s ± 2%  -17.11%  (p=0.002 n=6+6)

Change-Id: Ie43eb3bbe1392cbb61c86792a17a57b33b9561f0
Reviewed-on: https://go-review.googlesource.com/106796
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-04-24 01:05:27 +00:00
Matthew Dempsky
8f6ae33796 cmd/compile, cmd/link: encode cgo directives using JSON
The standard library has plenty of polished encoder/decoder
implementations. No need for another ad-hoc one.

I considered using encoding/gob instead, but these strings go into the
package data part of the object file, so it's important they don't
contain "\n$$\n". Package json escapes newlines in strings, so it's
safe to use here.

Change-Id: I998655524ccee7365c2c8e9a843e6975e95a3e62
Reviewed-on: https://go-review.googlesource.com/106463
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-04-11 23:35:42 +00:00
Matthew Dempsky
c3473c4f10 cmd/compile: refactor symbol sorting logic
This used to be duplicated in methcmp and siglt, because Sig used its
own representation for Syms. Instead, just use Syms, and add a
(*Sym).Less method that both methcmp and siglt can use.

Also, prune some impossible cases purportedly related to blank
methods: the Go spec disallows blank methods in interface method sets,
and addmethod drops blank methods without actually recording them in
the type's method set.

Passes toolstash-check.

Updates #24693.

Change-Id: I24e981659b68504d71518160486989a82505f513
Reviewed-on: https://go-review.googlesource.com/105936
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-04-09 22:58:21 +00:00
Matthew Dempsky
638f112d69 cmd/compile: cleanup method symbol creation
There were multiple ad hoc ways to create method symbols, with subtle
and confusing differences between them. This CL unifies them into a
single well-documented encoding and implementation.

This introduces some inconsequential changes to symbol format for the
sake of simplicity and consistency. Two notable changes:

1) Symbol construction is now insensitive to the package currently
being compiled. Previously, non-exported methods on anonymous types
received different method symbols depending on whether the method was
local or imported.

2) Symbols for method values parenthesized non-pointer receiver types
and non-exported method names, and also always package-qualified
non-exported method names. Now they use the same rules as normal
method symbols.

The methodSym function is also now stricter about rejecting
non-sensical method/receiver combinations. Notably, this means that
typecheckfunc needs to call addmethod to validate the method before
calling declare, which also means we no longer emit errors about
redeclaring bogus methods.

Change-Id: I9501c7a53dd70ef60e5c74603974e5ecc06e2003
Reviewed-on: https://go-review.googlesource.com/104876
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-04-05 22:01:17 +00:00
Daniel Martí
c15b7b2a54 cmd: re-generate all stringer files
The tool has gotten better over time, so re-generating the files brings
some advantages like fewer objects, dropping the use of fmt, and
dropping unnecessary bounds checks.

While at it, add the missing go:generate line for obj.AddrType.

Change-Id: I120c9795ee8faddf5961ff0384b9dcaf58d831ff
Reviewed-on: https://go-review.googlesource.com/100015
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-10 21:20:50 +00:00
Austin Clements
44e20b64ef cmd/compile: more String methods for prove types
These aid in debugging.

Change-Id: Ieb38c996765f780f6103f8c3292639d408c25123
Reviewed-on: https://go-review.googlesource.com/87476
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>
2018-03-08 22:25:23 +00:00
Robert Griesemer
5c08b9e8bd cmd/compile/internal/syntax: remove dependency on cmd/internal/src
For dependency reasons, the data structure implementing source
positions in the compiler is in cmd/internal/src. It contains
highly compiler specific details (e.g. inlining index).

This change introduces a parallel but simpler position
representation, defined in the syntax package, which removes
that package's dependency on cmd/internal/src, and also removes
the need to deal with certain filename-specific operations
(defined by the needs of the compiler) in the syntax package.
As a result, the syntax package becomes again a compiler-
independent, stand-alone package that at some point might
replace (or augment) the existing top-level go/* syntax-related
packages.

Additionally, line directives that update column numbers
are now correctly tracked through the syntax package, with
additional tests added. (The respective changes also need to
be made in cmd/internal/src; i.e., the compiler accepts but
still ignores column numbers in line directives.)

This change comes at the cost of a new position translation
step, but that step is cheap because it only needs to do real
work if the position base changed (i.e., if there is a new file,
or new line directive).

There is no noticeable impact on overall compiler performance
measured with `compilebench -count 5 -alloc`:

name       old time/op       new time/op       delta
Template         220ms ± 8%        228ms ±18%    ~     (p=0.548 n=5+5)
Unicode          119ms ±11%        113ms ± 5%    ~     (p=0.056 n=5+5)
GoTypes          684ms ± 6%        677ms ± 3%    ~     (p=0.841 n=5+5)
Compiler         3.19s ± 7%        3.01s ± 1%    ~     (p=0.095 n=5+5)
SSA              7.92s ± 8%        7.79s ± 1%    ~     (p=0.690 n=5+5)
Flate            141ms ± 7%        139ms ± 4%    ~     (p=0.548 n=5+5)
GoParser         173ms ±12%        171ms ± 4%    ~     (p=1.000 n=5+5)
Reflect          417ms ± 5%        411ms ± 3%    ~     (p=0.548 n=5+5)
Tar              205ms ± 5%        198ms ± 2%    ~     (p=0.690 n=5+5)
XML              232ms ± 4%        229ms ± 4%    ~     (p=0.690 n=5+5)
StdCmd           28.7s ± 5%        28.2s ± 2%    ~     (p=0.421 n=5+5)

name       old user-time/op  new user-time/op  delta
Template         269ms ± 4%        265ms ± 5%    ~     (p=0.421 n=5+5)
Unicode          153ms ± 7%        149ms ± 3%    ~     (p=0.841 n=5+5)
GoTypes          850ms ± 7%        862ms ± 4%    ~     (p=0.841 n=5+5)
Compiler         4.01s ± 5%        3.86s ± 0%    ~     (p=0.190 n=5+4)
SSA              10.9s ± 4%        10.8s ± 2%    ~     (p=0.548 n=5+5)
Flate            166ms ± 7%        167ms ± 6%    ~     (p=1.000 n=5+5)
GoParser         204ms ± 8%        206ms ± 7%    ~     (p=0.841 n=5+5)
Reflect          514ms ± 5%        508ms ± 4%    ~     (p=0.548 n=5+5)
Tar              245ms ± 6%        244ms ± 3%    ~     (p=0.690 n=5+5)
XML              280ms ± 4%        278ms ± 4%    ~     (p=0.841 n=5+5)

name       old alloc/op      new alloc/op      delta
Template        37.9MB ± 0%       37.9MB ± 0%    ~     (p=0.841 n=5+5)
Unicode         28.8MB ± 0%       28.8MB ± 0%    ~     (p=0.841 n=5+5)
GoTypes          113MB ± 0%        113MB ± 0%    ~     (p=0.151 n=5+5)
Compiler         468MB ± 0%        468MB ± 0%  -0.01%  (p=0.032 n=5+5)
SSA             1.50GB ± 0%       1.50GB ± 0%    ~     (p=0.548 n=5+5)
Flate           24.4MB ± 0%       24.4MB ± 0%    ~     (p=1.000 n=5+5)
GoParser        30.7MB ± 0%       30.7MB ± 0%    ~     (p=1.000 n=5+5)
Reflect         76.5MB ± 0%       76.5MB ± 0%    ~     (p=0.548 n=5+5)
Tar             38.9MB ± 0%       38.9MB ± 0%    ~     (p=0.222 n=5+5)
XML             41.6MB ± 0%       41.6MB ± 0%    ~     (p=0.548 n=5+5)

name       old allocs/op     new allocs/op     delta
Template          382k ± 0%         382k ± 0%  +0.01%  (p=0.008 n=5+5)
Unicode           343k ± 0%         343k ± 0%    ~     (p=0.841 n=5+5)
GoTypes          1.19M ± 0%        1.19M ± 0%  +0.01%  (p=0.008 n=5+5)
Compiler         4.53M ± 0%        4.53M ± 0%  +0.03%  (p=0.008 n=5+5)
SSA              12.4M ± 0%        12.4M ± 0%  +0.00%  (p=0.008 n=5+5)
Flate             235k ± 0%         235k ± 0%    ~     (p=0.079 n=5+5)
GoParser          318k ± 0%         318k ± 0%    ~     (p=0.730 n=5+5)
Reflect           978k ± 0%         978k ± 0%    ~     (p=1.000 n=5+5)
Tar               393k ± 0%         393k ± 0%    ~     (p=0.056 n=5+5)
XML               405k ± 0%         405k ± 0%    ~     (p=0.548 n=5+5)

name       old text-bytes    new text-bytes    delta
HelloSize        672kB ± 0%        672kB ± 0%    ~     (all equal)
CmdGoSize       7.12MB ± 0%       7.12MB ± 0%    ~     (all equal)

name       old data-bytes    new data-bytes    delta
HelloSize        133kB ± 0%        133kB ± 0%    ~     (all equal)
CmdGoSize        390kB ± 0%        390kB ± 0%    ~     (all equal)

name       old exe-bytes     new exe-bytes     delta
HelloSize       1.07MB ± 0%       1.07MB ± 0%    ~     (all equal)
CmdGoSize       11.2MB ± 0%       11.2MB ± 0%    ~     (all equal)

Passes toolstash compare.

For #22662.

Change-Id: I19edb53dd9675af57f7122cb7dba2a6d8bdcc3da
Reviewed-on: https://go-review.googlesource.com/94515
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-26 18:27:15 +00:00
Daniel Martí
c879153831 cmd/compile/internal/syntax: use stringer for operators and tokens
With its new -linecomment flag, it is now possible to use stringer on
values whose strings aren't valid identifiers. This is the case with
tokens and operators in Go.

Operator alredy had inline comments with each operator's string
representation; only minor modifications were needed. The inline
comments were added to each of the token names, using the same strategy.

Comments that were previously inline or part of the string arrays were
moved to the line immediately before the name they correspond to.

Finally, declare tokStrFast as a function that uses the generated arrays
directly. Avoiding the branch and strconv call means that we avoid a
performance regression in the scanner, perhaps due to the lack of
mid-stack inlining.

Performance is not affected. Measured with 'go test -run StdLib -fast'
on an X1 Carbon Gen2 (i5-4300U @ 1.90GHz, 8GB RAM, SSD), the best of 5
runs before and after the changes are:

	parsed 1709399 lines (3763 files) in 1.707402159s (1001169 lines/s)
	allocated 449.282Mb (263.137Mb/s)

	parsed 1709329 lines (3765 files) in 1.706663154s (1001562 lines/s)
	allocated 449.290Mb (263.256Mb/s)

Change-Id: Idcc4f83393fcadd6579700e3602c09496ea2625b
Reviewed-on: https://go-review.googlesource.com/95357
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-02-24 00:20:46 +00:00
Heschi Kreinick
438a757d73 cmd/compile/internal: reuse more memory
Reuse even more memory, and keep track of it in a long-lived debugState
object rather than piecemeal in the Cache.

Change-Id: Ib6936b4e8594dc6dda1f59ece753c00fd1c136ba
Reviewed-on: https://go-review.googlesource.com/92404
Reviewed-by: David Chase <drchase@google.com>
2018-02-21 18:10:00 +00:00
Heschi Kreinick
2075a9323d cmd/compile: reimplement location list generation
Completely redesign and reimplement location list generation to be more
efficient, and hopefully not too hard to understand.

RegKills are gone. Instead of using the regalloc's liveness
calculations, redo them using the Ops' clobber information. Besides
saving a lot of Values, this avoids adding RegKills to blocks that would
be empty otherwise, which was messing up optimizations. This does mean
that it's much harder to tell whether the generation process is buggy
(there's nothing to cross-check it with), and there may be disagreements
with GC liveness. But the performance gain is significant, and it's nice
not to be messing with earlier compiler phases.

The intermediate representations are gone. Instead of producing
ssa.BlockDebugs, then dwarf.LocationLists, and then finally real
location lists, go directly from the SSA to a (mostly) real location
list. Because the SSA analysis happens before assembly, it stores
encoded block/value IDs where PCs would normally go. It would be easier
to do the SSA analysis after assembly, but I didn't want to retain the
SSA just for that.

Generation proceeds in two phases: first, it traverses the function in
CFG order, storing the state of the block at the beginning and end. End
states are used to produce the start states of the successor blocks. In
the second phase, it traverses in program text order and produces the
location lists. The processing in the second phase is redundant, but
much cheaper than storing the intermediate representation. It might be
possible to combine the two phases somewhat to take advantage of cases
where the CFG matches the block layout, but I haven't tried.

Location lists are finalized by adding a base address selection entry,
translating each encoded block/value ID to a real PC, and adding the
terminating zero entry. This probably won't work on OSX, where dsymutil
will choke on the base address selection. I tried emitting CU-relative
relocations for each address, and it was *very* bad for performance --
it uses more memory storing all the relocations than it does for the
actual location list bytes. I think I'm going to end up synthesizing the
relocations in the linker only on OSX, but TBD.

TestNexting needs updating: with more optimizations working, the
debugger doesn't stop on the continue (line 88) any more, and the test's
duplicate suppression kicks in. Also, dx and dy live a little longer
now, but they have the correct values.

Change-Id: Ie772dfe23a4e389ca573624fac4d05401ae32307
Reviewed-on: https://go-review.googlesource.com/89356
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2018-02-14 18:29:19 +00:00
Robert Griesemer
52fcac3b7c cmd/compile/internal/syntax: implement regression test harness for syntax errors
R=go1.11

Fixes #20800.

Change-Id: Ifea273521d42a543a43da2f655ace7c295650e30
Reviewed-on: https://go-review.googlesource.com/88335
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-12 22:58:06 +00:00
Geoff Berry
75f0ad705f cmd/compile/internal/ssa: group dump files alphabetically
Change dump file names to group them alphabetically in directory
listings, in pass run order.

Change-Id: I8070578a5b4a3a7983dcc527ea1cfdb10a6d7d24
Reviewed-on: https://go-review.googlesource.com/83958
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-12-14 21:22:04 +00:00
David Chase
bd41c6783b cmd/compile: improve debugging output for GOSSAFUNC
This changes the assembly language output to use the
innermost (instead of outermost) position for line
number and file.

The file is printed separately, only when it changes,
to remove redundant and space-consuming noise from the
output.

Unknown positions have line number "?"

The output format was changed slightly to make it
easier to read.

One source of gratuitous variation in debugging output was
removed.

Change-Id: I1fd9c8b0ddd82766488582fb684dce4b04f35723
Reviewed-on: https://go-review.googlesource.com/78895
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-11-21 16:29:33 +00:00
Daniel Martí
3231d4e4ef cmd/compile: replace opnames with stringer
Now possible, since stringer just got the -trimprefix flag added.

While at it, simplify a few Op stringifications since we can now use %v,
and no longer have to worry about o<len(opnames).

Passes toolstash -cmp on std cmd.

Fixes #15462.

Change-Id: Icdcde0b0a5eb165d18488918175024da274f782b
Reviewed-on: https://go-review.googlesource.com/76790
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
2017-11-10 10:56:22 +00:00
Heschi Kreinick
73f1a1a1a7 cmd/compile/internal/ssa: use reverse postorder traversal
Instead of the hand-written control flow analysis in debug info
generation, use a reverse postorder traversal, which is basically the
same thing. It should be slightly faster.

More importantly, the previous version simply gave up in the case of
non-reducible functions, and produced output that caused a later stage
to crash. It turns out that there's a non-reducible function in
compress/flate, so that wasn't a theoretical issue.

With this change, all blocks will be visited, even for non-reducible
functions.

Change-Id: Id47536764ee93203c6b4105a1a3013fe3265aa12
Reviewed-on: https://go-review.googlesource.com/73110
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-10-24 20:22:05 +00:00
griesemer
4b7325c7e3 cmd/compile/internal/syntax: cleanups around parser tracing
These changes affect the parser only when the internal trace
constant is set.

- factored our printing code used for tracing
- streamlined advance function and added trace output

The parser's trace output now more clearly prints what tokens
are skipped and which is the next token in case of an error.

Example trace:

    4: . . . . . . . . . . call (
    4: . . . . . . . . . . . expr (
    4: . . . . . . . . . . . . unaryExpr (
    4: . . . . . . . . . . . . . pexpr (
    4: . . . . . . . . . . . . . . operand name (
    4: . . . . . . . . . . . . . . )
    4: . . . . . . . . . . . . . . call (
    4: . . . . . . . . . . . . . . )
    4: . . . . . . . . . . . . . )
    4: . . . . . . . . . . . . )
    4: . . . . . . . . . . . )
    4: . . . . . . . . . . . syntax error: expecting comma or )
    4: . . . . . . . . . . . skip ;
    6: . . . . . . . . . . . skip name
    6: . . . . . . . . . . . skip :=
    6: . . . . . . . . . . . skip literal
    6: . . . . . . . . . . . skip ;
    7: . . . . . . . . . . . skip }
    7: . . . . . . . . . . . skip ;
    9: . . . . . . . . . . . skip func
    9: . . . . . . . . . . . skip name
    9: . . . . . . . . . . . skip (
    9: . . . . . . . . . . . next )
    9: . . . . . . . . . . )

For #22164.

Change-Id: I4a233696b1f989ee3287472172afaf92cf424565
Reviewed-on: https://go-review.googlesource.com/70490
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-10-16 17:18:08 +00:00
David Chase
edcf2d0cd6 cmd/compile: add line numbers to values & blocks in ssa.html
In order to improve the line numbering for debuggers,
it's necessary to trace lines through compilation.
This makes it (much) easier to follow.

The format of the last column of the ssa.html output was
also changed to reduce the spamminess of the file name,
which is usually the same and makes it far harder to read
instructions and line numbers, and to make it wider and also
able to break words when wrapping (long path names still
can push off the end otherwise; side-to-side scrolling was
tried but was more annoying than the occasional wrapped
line).

Sample output now, where [...] is elision for sake of making
the CL character-counter happy -- and the (##) line numbers
are rendered in italics and a smaller font (11 point) under
control of a CSS class "line-number".

genssa
      # /Users/drchase/[...]/ssa/testdata/hist.go
      00000 (35) TEXT	"".main(SB)
      00001 (35) FUNCDATA	$0, gclocals·7be4bb[...]1e8b(SB)
      00002 (35) FUNCDATA	$1, gclocals·9ab98a[...]4568(SB)
v920  00003 (36) LEAQ	""..autotmp_31-640(SP), DI
v858  00004 (36) XORPS	X0, X0
v6    00005 (36) LEAQ	-48(DI), DI
v6    00006 (36) DUFFZERO	$277
v576  00007 (36) LEAQ	""..autotmp_31-640(SP), AX
v10   00008 (36) TESTB	AX, (AX)
b1    00009 (36) JMP	10

and from an earlier phase:

b18: ← b17
v242 (47) = Copy <mem> v238
v243 (47) = VarKill <mem> {.autotmp_16} v242
v244 (48) = Addr <**bufio.Scanner> {scanner} v2
v245 (48) = Load <*bufio.Scanner> v244 v243
[...]
v279 (49) = Store <mem> {int64} v277 v276 v278
v280 (49) = Addr <*error> {.autotmp_18} v2
v281 (49) = Load <error> v280 v279
v282 (49) = Addr <*error> {err} v2
v283 (49) = VarDef <mem> {err} v279
v284 (49) = Store <mem> {error} v282 v281 v283
v285 (47) = VarKill <mem> {.autotmp_18} v284
v286 (47) = VarKill <mem> {.autotmp_17} v285
v287 (50) = Addr <*error> {err} v2
v288 (50) = Load <error> v287 v286
v289 (50) = NeqInter <bool> v288 v51
If v289 → b21 b22 (line 50)

Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8
Reviewed-on: https://go-review.googlesource.com/69591
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-11 21:46:20 +00:00
Marvin Stenger
90d71fe99e all: revert "all: prefer strings.IndexByte over strings.Index"
This reverts https://golang.org/cl/65930.

Fixes #22148

Change-Id: Ie0712621ed89c43bef94417fc32de9af77607760
Reviewed-on: https://go-review.googlesource.com/68430
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-05 23:19:10 +00:00
Heschi Kreinick
6bbe1bc940 cmd/compile: cover control flow insns in location lists
The information that's used to generate DWARF location lists is very
ssa.Value centric; it uses Values as start and end coordinates to define
ranges. That mostly works fine, but control flow instructions don't come
from Values, so the ranges couldn't cover them.

Control flow instructions are generated when the SSA representation is
converted to assembly, so that's the best place to extend the ranges
to cover them. (Before that, there's nothing to refer to, and afterward
the boundaries between blocks have been lost.) That requires block
information in the debugInfo type, which then flows down to make
everything else awkward. On the plus side, there's a little less copying
slices around than there used to be, so it should be a little faster.

Previously, the ranges for empty blocks were not very meaningful. That
was fine, because they had no Values to cover, so no debug information
was generated for them. But they do have control flow instructions
(that's why they exist) and so now it's important that the information
be correct. Introduce two sentinel values, BlockStart and BlockEnd, that
denote the boundary of a block, even if the block is empty. BlockEnd
replaces the previous SurvivedBlock flag.

There's one more problem: the last instruction in the function will be a
control flow instruction, so any live ranges need to be extended past
it. But there's no instruction after it to use as the end of the range.
Instead, leave the EndProg field of those ranges as nil and fix it up to
point to past the end of the assembled text at the very last moment.

Change-Id: I81f884020ff36fd6fe8d7888fc57c99412c4245b
Reviewed-on: https://go-review.googlesource.com/63010
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-09-28 20:30:12 +00:00
Marvin Stenger
f22ba1f247 all: prefer strings.IndexByte over strings.Index
strings.IndexByte was introduced in go1.2 and it can be used
effectively wherever the second argument to strings.Index is
exactly one byte long.

This avoids generating unnecessary string symbols and saves
a few calls to strings.Index.

Change-Id: I1ab5edb7c4ee9058084cfa57cbcc267c2597e793
Reviewed-on: https://go-review.googlesource.com/65930
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-09-25 17:35:41 +00:00
Keith Randall
1787ced894 cmd/compile: remove Symbol wrappers from Aux fields
We used to have {Arg,Auto,Extern}Symbol structs with which we wrapped
a *gc.Node or *obj.LSym before storing them in the Aux field
of an ssa.Value.  This let the SSA part of the compiler distinguish
between autos and args, for example.  We no longer need the wrappers
as we can query the underlying objects directly.

There was also some sloppy usage, where VarDef had a *gc.Node
directly in its Aux field, whereas the use of that variable had
that *gc.Node wrapped in an AutoSymbol. Thus the Aux fields didn't
match (using ==) when they probably should.
This sloppy usage cleanup is the only thing in the CL that changes the
generated code - we can get rid of some more unused auto variables if
the matching happens reliably.

Removing this wrapper also lets us get rid of the varsyms cache
(which was used to prevent wrapping the same *gc.Node twice).

Change-Id: I0dedf8f82f84bfee413d310342b777316bd1d478
Reviewed-on: https://go-review.googlesource.com/64452
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-09-19 22:03:10 +00:00
Daniel Martí
99da8730b0 all: remove some double spaces from comments
Went mainly for the ones that make no sense, such as the ones
mid-sentence or after commas.

Change-Id: Ie245d2c19cc7428a06295635cf6a9482ade25ff0
Reviewed-on: https://go-review.googlesource.com/57293
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-26 15:09:09 +00:00
Keith Randall
bf4d8d3d05 cmd/compile: rename SSA Register.Name to Register.String
Just to get rid of lots of .Name() stutter in printf calls.

Change-Id: I86cf00b3f7b2172387a1c6a7f189c1897fab6300
Reviewed-on: https://go-review.googlesource.com/56630
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-08-17 21:53:08 +00:00
Heschi Kreinick
4c54a047c6 [dev.debug] cmd/compile: better DWARF with optimizations on
Debuggers use DWARF information to find local variables on the
stack and in registers. Prior to this CL, the DWARF information for
functions claimed that all variables were on the stack at all times.
That's incorrect when optimizations are enabled, and results in
debuggers showing data that is out of date or complete gibberish.

After this CL, the compiler is capable of representing variable
locations more accurately, and attempts to do so. Due to limitations of
the SSA backend, it's not possible to be completely correct.

There are a number of problems in the current design. One of the easier
to understand is that variable names currently must be attached to an
SSA value, but not all assignments in the source code actually result
in machine code. For example:

  type myint int
  var a int
  b := myint(int)
and
  b := (*uint64)(unsafe.Pointer(a))

don't generate machine code because the underlying representation is the
same, so the correct value of b will not be set when the user would
expect.

Generating the more precise debug information is behind a flag,
dwarflocationlists. Because of the issues described above, setting the
flag may not make the debugging experience much better, and may actually
make it worse in cases where the variable actually is on the stack and
the more complicated analysis doesn't realize it.

A number of changes are included:
- Add a new pseudo-instruction, RegKill, which indicates that the value
in the register has been clobbered.
- Adjust regalloc to emit RegKills in the right places. Significantly,
this means that phis are mixed with StoreReg and RegKills after
regalloc.
- Track variable decomposition in ssa.LocalSlots.
- After the SSA backend is done, analyze the result and build location
lists for each LocalSlot.
- After assembly is done, update the location lists with the assembled
PC offsets, recompose variables, and build DWARF location lists. Emit the
list as a new linker symbol, one per function.
- In the linker, aggregate the location lists into a .debug_loc section.

TODO:
- currently disabled for non-X86/AMD64 because there are no data tables.

go build -toolexec 'toolstash -cmp' -a std succeeds.

With -dwarflocationlists false:
before: f02812195637909ff675782c0b46836a8ff01976
after:  06f61e8112a42ac34fb80e0c818b3cdb84a5e7ec
benchstat -geomean  /tmp/220352263 /tmp/621364410
completed   15 of   15, estimated time remaining 0s (eta 3:52PM)
name        old time/op       new time/op       delta
Template          199ms ± 3%        198ms ± 2%     ~     (p=0.400 n=15+14)
Unicode          96.6ms ± 5%       96.4ms ± 5%     ~     (p=0.838 n=15+15)
GoTypes           653ms ± 2%        647ms ± 2%     ~     (p=0.102 n=15+14)
Flate             133ms ± 6%        129ms ± 3%   -2.62%  (p=0.041 n=15+15)
GoParser          164ms ± 5%        159ms ± 3%   -3.05%  (p=0.000 n=15+15)
Reflect           428ms ± 4%        422ms ± 3%     ~     (p=0.156 n=15+13)
Tar               123ms ±10%        124ms ± 8%     ~     (p=0.461 n=15+15)
XML               228ms ± 3%        224ms ± 3%   -1.57%  (p=0.045 n=15+15)
[Geo mean]        206ms             377ms       +82.86%

name        old user-time/op  new user-time/op  delta
Template          292ms ±10%        301ms ±12%     ~     (p=0.189 n=15+15)
Unicode           166ms ±37%        158ms ±14%     ~     (p=0.418 n=15+14)
GoTypes           962ms ± 6%        963ms ± 7%     ~     (p=0.976 n=15+15)
Flate             207ms ±19%        200ms ±14%     ~     (p=0.345 n=14+15)
GoParser          246ms ±22%        240ms ±15%     ~     (p=0.587 n=15+15)
Reflect           611ms ±13%        587ms ±14%     ~     (p=0.085 n=15+13)
Tar               211ms ±12%        217ms ±14%     ~     (p=0.355 n=14+15)
XML               335ms ±15%        320ms ±18%     ~     (p=0.169 n=15+15)
[Geo mean]        317ms             583ms       +83.72%

name        old alloc/op      new alloc/op      delta
Template         40.2MB ± 0%       40.2MB ± 0%   -0.15%  (p=0.000 n=14+15)
Unicode          29.2MB ± 0%       29.3MB ± 0%     ~     (p=0.624 n=15+15)
GoTypes           114MB ± 0%        114MB ± 0%   -0.15%  (p=0.000 n=15+14)
Flate            25.7MB ± 0%       25.6MB ± 0%   -0.18%  (p=0.000 n=13+15)
GoParser         32.2MB ± 0%       32.2MB ± 0%   -0.14%  (p=0.003 n=15+15)
Reflect          77.8MB ± 0%       77.9MB ± 0%     ~     (p=0.061 n=15+15)
Tar              27.1MB ± 0%       27.0MB ± 0%   -0.11%  (p=0.029 n=15+15)
XML              42.7MB ± 0%       42.5MB ± 0%   -0.29%  (p=0.000 n=15+15)
[Geo mean]       42.1MB            75.0MB       +78.05%

name        old allocs/op     new allocs/op     delta
Template           402k ± 1%         398k ± 0%   -0.91%  (p=0.000 n=15+15)
Unicode            344k ± 1%         344k ± 0%     ~     (p=0.715 n=15+14)
GoTypes           1.18M ± 0%        1.17M ± 0%   -0.91%  (p=0.000 n=15+14)
Flate              243k ± 0%         240k ± 1%   -1.05%  (p=0.000 n=13+15)
GoParser           327k ± 1%         324k ± 1%   -0.96%  (p=0.000 n=15+15)
Reflect            984k ± 1%         982k ± 0%     ~     (p=0.050 n=15+15)
Tar                261k ± 1%         259k ± 1%   -0.77%  (p=0.000 n=15+15)
XML                411k ± 0%         404k ± 1%   -1.55%  (p=0.000 n=15+15)
[Geo mean]         439k              755k       +72.01%

name        old text-bytes    new text-bytes    delta
HelloSize         694kB ± 0%        694kB ± 0%   -0.00%  (p=0.000 n=15+15)

name        old data-bytes    new data-bytes    delta
HelloSize        5.55kB ± 0%       5.55kB ± 0%     ~     (all equal)

name        old bss-bytes     new bss-bytes     delta
HelloSize         133kB ± 0%        133kB ± 0%     ~     (all equal)

name        old exe-bytes     new exe-bytes     delta
HelloSize        1.04MB ± 0%       1.04MB ± 0%     ~     (all equal)

Change-Id: I991fc553ef175db46bb23b2128317bbd48de70d8
Reviewed-on: https://go-review.googlesource.com/41770
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-07-27 20:19:44 +00:00
Josh Bleecher Snyder
46b88c9fbc cmd/compile: change ssa.Type into *types.Type
When package ssa was created, Type was in package gc.
To avoid circular dependencies, we used an interface (ssa.Type)
to represent type information in SSA.

In the Go 1.9 cycle, gri extricated the Type type from package gc.
As a result, we can now use it in package ssa.
Now, instead of package types depending on package ssa,
it is the other way.
This is a more sensible dependency tree,
and helps compiler performance a bit.

Though this is a big CL, most of the changes are
mechanical and uninteresting.

Interesting bits:

* Add new singleton globals to package types for the special
  SSA types Memory, Void, Invalid, Flags, and Int128.
* Add two new Types, TSSA for the special types,
  and TTUPLE, for SSA tuple types.
  ssa.MakeTuple is now types.NewTuple.
* Move type comparison result constants CMPlt, CMPeq, and CMPgt
  to package types.
* We had picked the name "types" in our rules for the handy
  list of types provided by ssa.Config. That conflicted with
  the types package name, so change it to "typ".
* Update the type comparison routine to handle tuples and special
  types inline.
* Teach gc/fmt.go how to print special types.
* We can now eliminate ElemTypes in favor of just Elem,
  and probably also some other duplicated Type methods
  designed to return ssa.Type instead of *types.Type.
* The ssa tests were using their own dummy types,
  and they were not particularly careful about types in general.
  Of necessity, this CL switches them to use *types.Type;
  it does not make them more type-accurate.
  Unfortunately, using types.Type means initializing a bit
  of the types universe.
  This is prime for refactoring and improvement.

This shrinks ssa.Value; it now fits in a smaller size class
on 64 bit systems. This doesn't have a giant impact,
though, since most Values are preallocated in a chunk.

name        old alloc/op      new alloc/op      delta
Template         37.9MB ± 0%       37.7MB ± 0%  -0.57%  (p=0.000 n=10+8)
Unicode          28.9MB ± 0%       28.7MB ± 0%  -0.52%  (p=0.000 n=10+10)
GoTypes           110MB ± 0%        109MB ± 0%  -0.88%  (p=0.000 n=10+10)
Flate            24.7MB ± 0%       24.6MB ± 0%  -0.66%  (p=0.000 n=10+10)
GoParser         31.1MB ± 0%       30.9MB ± 0%  -0.61%  (p=0.000 n=10+9)
Reflect          73.9MB ± 0%       73.4MB ± 0%  -0.62%  (p=0.000 n=10+8)
Tar              25.8MB ± 0%       25.6MB ± 0%  -0.77%  (p=0.000 n=9+10)
XML              41.2MB ± 0%       40.9MB ± 0%  -0.80%  (p=0.000 n=10+10)
[Geo mean]       40.5MB            40.3MB       -0.68%

name        old allocs/op     new allocs/op     delta
Template           385k ± 0%         386k ± 0%    ~     (p=0.356 n=10+9)
Unicode            343k ± 1%         344k ± 0%    ~     (p=0.481 n=10+10)
GoTypes           1.16M ± 0%        1.16M ± 0%  -0.16%  (p=0.004 n=10+10)
Flate              238k ± 1%         238k ± 1%    ~     (p=0.853 n=10+10)
GoParser           320k ± 0%         320k ± 0%    ~     (p=0.720 n=10+9)
Reflect            957k ± 0%         957k ± 0%    ~     (p=0.460 n=10+8)
Tar                252k ± 0%         252k ± 0%    ~     (p=0.133 n=9+10)
XML                400k ± 0%         400k ± 0%    ~     (p=0.796 n=10+10)
[Geo mean]         428k              428k       -0.01%


Removing all the interface calls helps non-trivially with CPU, though.

name        old time/op       new time/op       delta
Template          178ms ± 4%        173ms ± 3%  -2.90%  (p=0.000 n=94+96)
Unicode          85.0ms ± 4%       83.9ms ± 4%  -1.23%  (p=0.000 n=96+96)
GoTypes           543ms ± 3%        528ms ± 3%  -2.73%  (p=0.000 n=98+96)
Flate             116ms ± 3%        113ms ± 4%  -2.34%  (p=0.000 n=96+99)
GoParser          144ms ± 3%        140ms ± 4%  -2.80%  (p=0.000 n=99+97)
Reflect           344ms ± 3%        334ms ± 4%  -3.02%  (p=0.000 n=100+99)
Tar               106ms ± 5%        103ms ± 4%  -3.30%  (p=0.000 n=98+94)
XML               198ms ± 5%        192ms ± 4%  -2.88%  (p=0.000 n=92+95)
[Geo mean]        178ms             173ms       -2.65%

name        old user-time/op  new user-time/op  delta
Template          229ms ± 5%        224ms ± 5%  -2.36%  (p=0.000 n=95+99)
Unicode           107ms ± 6%        106ms ± 5%  -1.13%  (p=0.001 n=93+95)
GoTypes           696ms ± 4%        679ms ± 4%  -2.45%  (p=0.000 n=97+99)
Flate             137ms ± 4%        134ms ± 5%  -2.66%  (p=0.000 n=99+96)
GoParser          176ms ± 5%        172ms ± 8%  -2.27%  (p=0.000 n=98+100)
Reflect           430ms ± 6%        411ms ± 5%  -4.46%  (p=0.000 n=100+92)
Tar               128ms ±13%        123ms ±13%  -4.21%  (p=0.000 n=100+100)
XML               239ms ± 6%        233ms ± 6%  -2.50%  (p=0.000 n=95+97)
[Geo mean]        220ms             213ms       -2.76%


Change-Id: I15c7d6268347f8358e75066dfdbd77db24e8d0c1
Reviewed-on: https://go-review.googlesource.com/42145
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-05-09 23:01:51 +00:00
Josh Bleecher Snyder
386765afdf cmd/compile: move Node.Class to flags
Put it at position zero, since it is fairly hot.

This shrinks gc.Node into a smaller size class on 64 bit systems.

name        old time/op       new time/op       delta
Template          193ms ± 5%        192ms ± 3%    ~     (p=0.353 n=94+93)
Unicode          86.1ms ± 5%       85.0ms ± 4%  -1.23%  (p=0.000 n=95+98)
GoTypes           546ms ± 3%        544ms ± 4%  -0.40%  (p=0.007 n=94+97)
Compiler          2.56s ± 3%        2.54s ± 3%  -0.67%  (p=0.000 n=99+97)
SSA               5.13s ± 2%        5.10s ± 3%  -0.55%  (p=0.000 n=94+98)
Flate             122ms ± 6%        121ms ± 4%  -0.75%  (p=0.002 n=97+95)
GoParser          144ms ± 5%        144ms ± 4%    ~     (p=0.298 n=98+97)
Reflect           348ms ± 4%        349ms ± 4%    ~     (p=0.350 n=98+97)
Tar               105ms ± 5%        104ms ± 5%    ~     (p=0.154 n=96+98)
XML               200ms ± 5%        198ms ± 4%  -0.71%  (p=0.015 n=97+98)
[Geo mean]        330ms             328ms       -0.52%

name        old user-time/op  new user-time/op  delta
Template          229ms ±11%        224ms ± 7%  -2.16%  (p=0.001 n=100+87)
Unicode           109ms ± 5%        109ms ± 6%    ~     (p=0.897 n=96+91)
GoTypes           712ms ± 4%        709ms ± 4%    ~     (p=0.085 n=96+98)
Compiler          3.41s ± 3%        3.36s ± 3%  -1.43%  (p=0.000 n=98+98)
SSA               7.46s ± 3%        7.31s ± 3%  -2.02%  (p=0.000 n=100+99)
Flate             145ms ± 6%        143ms ± 6%  -1.11%  (p=0.001 n=99+97)
GoParser          177ms ± 5%        176ms ± 5%  -0.78%  (p=0.018 n=95+95)
Reflect           432ms ± 7%        435ms ± 9%    ~     (p=0.296 n=100+100)
Tar               121ms ± 7%        121ms ± 5%    ~     (p=0.072 n=100+95)
XML               241ms ± 4%        239ms ± 5%    ~     (p=0.085 n=97+99)
[Geo mean]        413ms             410ms       -0.73%

name        old alloc/op      new alloc/op      delta
Template         38.4MB ± 0%       37.7MB ± 0%  -1.85%  (p=0.008 n=5+5)
Unicode          30.1MB ± 0%       28.8MB ± 0%  -4.09%  (p=0.008 n=5+5)
GoTypes           112MB ± 0%        110MB ± 0%  -1.69%  (p=0.008 n=5+5)
Compiler          470MB ± 0%        461MB ± 0%  -1.91%  (p=0.008 n=5+5)
SSA              1.13GB ± 0%       1.11GB ± 0%  -1.70%  (p=0.008 n=5+5)
Flate            25.0MB ± 0%       24.6MB ± 0%  -1.67%  (p=0.008 n=5+5)
GoParser         31.6MB ± 0%       31.1MB ± 0%  -1.66%  (p=0.008 n=5+5)
Reflect          77.1MB ± 0%       75.8MB ± 0%  -1.69%  (p=0.008 n=5+5)
Tar              26.3MB ± 0%       25.7MB ± 0%  -2.06%  (p=0.008 n=5+5)
XML              41.9MB ± 0%       41.1MB ± 0%  -1.93%  (p=0.008 n=5+5)
[Geo mean]       73.5MB            72.0MB       -2.03%

name        old allocs/op     new allocs/op     delta
Template           383k ± 0%         383k ± 0%    ~     (p=0.690 n=5+5)
Unicode            343k ± 0%         343k ± 0%    ~     (p=0.841 n=5+5)
GoTypes           1.16M ± 0%        1.16M ± 0%    ~     (p=0.310 n=5+5)
Compiler          4.43M ± 0%        4.42M ± 0%  -0.17%  (p=0.008 n=5+5)
SSA               9.85M ± 0%        9.85M ± 0%    ~     (p=0.310 n=5+5)
Flate              236k ± 0%         236k ± 1%    ~     (p=0.841 n=5+5)
GoParser           320k ± 0%         320k ± 0%    ~     (p=0.421 n=5+5)
Reflect            988k ± 0%         987k ± 0%    ~     (p=0.690 n=5+5)
Tar                252k ± 0%         251k ± 0%    ~     (p=0.095 n=5+5)
XML                399k ± 0%         399k ± 0%    ~     (p=1.000 n=5+5)
[Geo mean]         741k              740k       -0.07%

Change-Id: I9e952b58a98e30a12494304db9ce50d0a85e459c
Reviewed-on: https://go-review.googlesource.com/41797
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Marvin Stenger <marvin.stenger94@gmail.com>
2017-04-26 16:58:33 +00:00
Damien Lespiau
f9be63b9ba cmd/compile: provide a way to auto-discover -d debug keys
Currently one needs to refer to the sources to have a list of accepted
debug keys. We can copy what 'ssa/help' does and introspect the list of
debug keys to print a more detailed help:

    $ go tool compile -d help
    usage: -d arg[,arg]* and arg is <key>[=<value>]

    <key> is one of:

    	append    	print information about append compilation
    	closure   	print information about closure compilation
    	disablenil	disable nil checks
    	dclstack  	run internal dclstack check
    	gcprog    	print dump of GC programs
    	nil       	print information about nil checks
    	panic     	do not hide any compiler panic
    	slice     	print information about slice compilation
    	typeassert	print information about type assertion inlining
    	wb        	print information about write barriers
    	export    	print export data
    	pctab     	print named pc-value table
    	ssa/help  	print help about SSA debugging

    <value> is key-specific.

    Key "pctab" supports values:
    	"pctospadj", "pctofile", "pctoline", "pctoinline", "pctopcdata"

For '-d help' to be discoverable, a hint is given in the -d flag
description.

A last thing, today at least one go file needs to be provided to get to
the code printing ssa/help.

  $ go tool compile -d ssa/help foo.go

Add a check so one can just do '-d help' or '-d ssa/help'

Caught by trybot: I needed to update fmt_test.go as I'm introducing the
usage of %-*s in a format string.

Fixes #20041

Change-Id: Ib2858b038c1bcbe644aa3b1a371009710c6d957d
Reviewed-on: https://go-review.googlesource.com/41091
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-04-21 20:30:27 +00:00
Todd Neal
dc444418d9 cmd/internal: remove duplicate pathToPrefix function
goobj.importPathToPrefix is 3x faster than gc.pathToPrefix so rename and
move it to cmd/internal/objabi which is already imported by both goobj and
gc.

Change-Id: I10eda5bce95ef6d5d888818c5c47258c2833ea45
Reviewed-on: https://go-review.googlesource.com/40875
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-19 11:47:45 +00:00
David Chase
073297ff68 cmd/compile: enhance postorder computation and repair loop finder
Replace derecursed postorder computation with one that
mimics DFS traversal.

Corrected outerinner function in loopfinder

Leave enhanced checks in place.

Change-Id: I657ba5e89c88941028d6d4c72e9f9056e30f1ce8
Reviewed-on: https://go-review.googlesource.com/40872
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2017-04-19 02:57:23 +00:00
Josh Bleecher Snyder
da15fe6870 cmd/internal/obj: rework gclocals handling
The compiler handled gcargs and gclocals LSyms unusually.
It generated placeholder symbols (makefuncdatasym),
filled them in, and then renamed them for content-addressability.
This is an important binary size optimization;
the same locals information occurs over and over.

This CL continues to treat these LSyms unusually,
but in a slightly more explicit way,
and importantly for concurrent compilation,
in a way that does not require concurrent
modification of Ctxt.Hash.

Instead of creating gcargs and gclocals in the usual way,
by creating a types.Sym and then an obj.LSym,
we add them directly to obj.FuncInfo,
initialize them in obj.InitTextSym,
and deduplicate and add them to ctxt.Data at the end.
Then the backend's job is simply to fill them in
and rename them appropriately.

Updates #15756

name       old alloc/op      new alloc/op      delta
Template        38.8MB ± 0%       38.7MB ± 0%  -0.22%  (p=0.016 n=5+5)
Unicode         29.8MB ± 0%       29.8MB ± 0%    ~     (p=0.690 n=5+5)
GoTypes          113MB ± 0%        113MB ± 0%  -0.24%  (p=0.008 n=5+5)
SSA             1.25GB ± 0%       1.24GB ± 0%  -0.39%  (p=0.008 n=5+5)
Flate           25.3MB ± 0%       25.2MB ± 0%  -0.43%  (p=0.008 n=5+5)
GoParser        31.7MB ± 0%       31.7MB ± 0%  -0.22%  (p=0.008 n=5+5)
Reflect         78.2MB ± 0%       77.6MB ± 0%  -0.80%  (p=0.008 n=5+5)
Tar             26.6MB ± 0%       26.3MB ± 0%  -0.85%  (p=0.008 n=5+5)
XML             42.4MB ± 0%       41.9MB ± 0%  -1.04%  (p=0.008 n=5+5)

name       old allocs/op     new allocs/op     delta
Template          378k ± 0%         377k ± 1%    ~     (p=0.151 n=5+5)
Unicode           321k ± 1%         321k ± 0%    ~     (p=0.841 n=5+5)
GoTypes          1.14M ± 0%        1.14M ± 0%  -0.47%  (p=0.016 n=5+5)
SSA              9.71M ± 0%        9.67M ± 0%  -0.33%  (p=0.008 n=5+5)
Flate             233k ± 1%         232k ± 1%    ~     (p=0.151 n=5+5)
GoParser          316k ± 0%         315k ± 0%  -0.49%  (p=0.016 n=5+5)
Reflect           979k ± 0%         972k ± 0%  -0.75%  (p=0.008 n=5+5)
Tar               250k ± 0%         247k ± 1%  -0.92%  (p=0.008 n=5+5)
XML               392k ± 1%         389k ± 0%  -0.67%  (p=0.008 n=5+5)

Change-Id: Idc36186ca9d2f8214b5f7720bbc27b6bb22fdc48
Reviewed-on: https://go-review.googlesource.com/40697
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-18 02:13:32 +00:00
Robert Griesemer
f68f292820 cmd/compile: factor out Pkg, Sym, and Type into package types
- created new package cmd/compile/internal/types
- moved Pkg, Sym, Type to new package
- to break cycles, for now we need the (ugly) types/utils.go
  file which contains a handful of functions that must be installed
  early by the gc frontend
- to break cycles, for now we need two functions to convert between
  *gc.Node and *types.Node (the latter is a dummy type)
- adjusted the gc's code to use the new package and the conversion
  functions as needed
- made several Pkg, Sym, and Type methods functions as needed
- renamed constructors typ, typPtr, typArray, etc. to types.New,
  types.NewPtr, types.NewArray, etc.

Passes toolstash-check -all.

Change-Id: I8adfa5e85c731645d0a7fd2030375ed6ebf54b72
Reviewed-on: https://go-review.googlesource.com/39855
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-07 03:04:00 +00:00
Josh Bleecher Snyder
99683483d6 cmd/internal/obj: unify creation of numeric literal syms
This is a straightforward refactoring,
to reduce the scope of upcoming changes.

The symbol size and AttrLocal=true was not
set universally, but it appears not to matter,
since toolstash -cmp is happy.

Passes toolstash-check -all.

Change-Id: I7f8392f939592d3a1bc6f61dec992f5661f42fca
Reviewed-on: https://go-review.googlesource.com/39791
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-06 19:01:50 +00:00
Josh Bleecher Snyder
4927b9a9ff cmd/compile: remove makefuncdatasym_nsym global
This causes a minor reduction in allocations,
because the old funcdatasym names were
being interned unnecessarily.

Updates #15756

name       old alloc/op    new alloc/op    delta
Template      39.9MB ± 0%     39.9MB ± 0%    ~     (p=0.280 n=10+10)
Unicode       29.9MB ± 0%     29.8MB ± 0%  -0.26%  (p=0.000 n=10+10)
GoTypes        113MB ± 0%      113MB ± 0%  -0.12%  (p=0.000 n=10+10)
SSA            855MB ± 0%      855MB ± 0%  -0.03%  (p=0.001 n=10+10)
Flate         25.4MB ± 0%     25.3MB ± 0%  -0.30%  (p=0.000 n=10+10)
GoParser      31.9MB ± 0%     31.8MB ± 0%    ~     (p=0.065 n=10+9)
Reflect       78.4MB ± 0%     78.2MB ± 0%  -0.15%  (p=0.000 n=9+10)
Tar           26.7MB ± 0%     26.7MB ± 0%  -0.17%  (p=0.000 n=9+10)
XML           42.3MB ± 0%     42.4MB ± 0%  +0.07%  (p=0.011 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        390k ± 0%       390k ± 0%    ~     (p=0.905 n=9+10)
Unicode         319k ± 1%       319k ± 1%    ~     (p=0.724 n=10+10)
GoTypes        1.14M ± 0%      1.14M ± 0%    ~     (p=0.393 n=10+10)
SSA            7.60M ± 0%      7.60M ± 0%    ~     (p=0.604 n=9+10)
Flate           235k ± 1%       234k ± 1%    ~     (p=0.105 n=10+10)
GoParser        317k ± 0%       316k ± 1%    ~     (p=0.280 n=10+10)
Reflect         979k ± 0%       979k ± 0%    ~     (p=0.315 n=10+10)
Tar             251k ± 0%       251k ± 1%    ~     (p=0.762 n=8+10)
XML             393k ± 0%       394k ± 1%    ~     (p=0.095 n=9+10)

name       old text-bytes  new text-bytes  delta
HelloSize       684k ± 0%       684k ± 0%    ~     (all equal)

name       old data-bytes  new data-bytes  delta
HelloSize       138k ± 0%       138k ± 0%    ~     (all equal)

name       old exe-bytes   new exe-bytes   delta
HelloSize      1.03M ± 0%      1.03M ± 0%    ~     (all equal)

Change-Id: Idba33da4e89c325984ac46e4852cf12e4a7fd1a9
Reviewed-on: https://go-review.googlesource.com/39032
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-03-31 19:53:26 +00:00
Robert Griesemer
d1f5e5f482 cmd/compile/internal/syntax: always construct a correct syntax tree
- parser creates sensible nodes in case of syntax errors instead of nil
- a new BadExpr node is used in places where we can't do better
- fixed error message for incorrect type switch guard
- minor cleanups

Fixes #19663.

Change-Id: I028394c6db9cba7371f0e417ebf93f594659786a
Reviewed-on: https://go-review.googlesource.com/38653
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-25 21:01:49 +00:00
Josh Bleecher Snyder
352e19c92c cmd/compile: eliminate Gins and Naddr
Preparation for eliminating Prog-related globals.

Passes toolstash-check -all.

Updates #15756

Change-Id: Ia199fcb282cc3a84903a6e92a3ce342c5faba79c
Reviewed-on: https://go-review.googlesource.com/38409
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-22 19:05:52 +00:00
Matthew Dempsky
8ada52228c cmd/compile: remove ProgInfo tables
Change-Id: Id807c702ad71edddd23f2eb6f5e69e9a62e60bcd
Reviewed-on: https://go-review.googlesource.com/38089
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-03-20 23:29:51 +00:00
Matthew Dempsky
325904fe6a cmd/compile: port liveness analysis to SSA
Passes toolstash-check -all.

Change-Id: I92c3c25d6c053f971f346f4fa3bbc76419b58183
Reviewed-on: https://go-review.googlesource.com/38087
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-03-20 22:58:50 +00:00
Cherry Zhang
c8f38b3398 cmd/compile: use type information in Aux for Store size
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>
2017-03-16 14:25:04 +00:00
Josh Bleecher Snyder
723ba180b3 cmd/compile: eliminate fmtmode and fmtpkgpfx globals
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>
2017-03-14 21:20:25 +00:00
Matthew Dempsky
68177d9ec0 cmd/internal/obj: move dwarf.Var generation into compiler
Passes toolstash -cmp.

Change-Id: I4bd60f7ebba5457e7b3ece688fee2351bfeeb59a
Reviewed-on: https://go-review.googlesource.com/37874
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2017-03-07 17:32:54 +00:00
Michael Munday
8d3f29577d cmd/compile: regenerate knownFormats
Should fix the build dashboard.

Change-Id: Id4c8a996d9f689e1fa865a9cff9a7f52c700c691
Reviewed-on: https://go-review.googlesource.com/37877
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-07 01:09:50 +00:00
Keith Randall
708ba22a0c cmd/compile: move constant divide strength reduction to SSA rules
Currently the conversion from constant divides to multiplies is mostly
done during the walk pass.  This is suboptimal because SSA can
determine that the value being divided by is constant more often
(e.g. after inlining).

Change-Id: If1a9b993edd71be37396b9167f77da271966f85f
Reviewed-on: https://go-review.googlesource.com/37015
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-02-17 06:16:44 +00:00
Matthew Dempsky
8cf1766930 cmd/compile/internal/ssa: use *obj.LSym in ExternSymbol
Change-Id: I713120f90fd1d2df6698c40622ccac6eae907919
Reviewed-on: https://go-review.googlesource.com/36423
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-02-07 20:49:44 +00:00
Robert Griesemer
4808fc4443 [dev.inline] cmd/internal/src: replace src.Pos with syntax.Pos
This replaces the src.Pos LineHist-based position tracking with
the syntax.Pos implementation and updates all uses.

The LineHist table is not used anymore - the respective code is still
there but should be removed eventually. CL forthcoming.

Passes toolstash -cmp when comparing to the master repo (with the
exception of a couple of swapped assembly instructions, likely due
to different instruction scheduling because the line-based sorting
has changed; though this is won't affect correctness).

The sizes of various important compiler data structures have increased
significantly (see the various sizes_test.go files); this is probably
the reason for an increase of compilation times (to be addressed). Here
are the results of compilebench -count 5, run on a "quiet" machine (no
apps running besides a terminal):

name       old time/op     new time/op     delta
Template       256ms ± 1%      280ms ±15%  +9.54%          (p=0.008 n=5+5)
Unicode        132ms ± 1%      132ms ± 1%    ~             (p=0.690 n=5+5)
GoTypes        891ms ± 1%      917ms ± 2%  +2.88%          (p=0.008 n=5+5)
Compiler       3.84s ± 2%      3.99s ± 2%  +3.95%          (p=0.016 n=5+5)
MakeBash       47.1s ± 1%      47.2s ± 2%    ~             (p=0.841 n=5+5)

name       old user-ns/op  new user-ns/op  delta
Template        309M ± 1%       326M ± 2%  +5.18%          (p=0.008 n=5+5)
Unicode         165M ± 1%       168M ± 4%    ~             (p=0.421 n=5+5)
GoTypes        1.14G ± 2%      1.18G ± 1%  +3.47%          (p=0.008 n=5+5)
Compiler       5.00G ± 1%      5.16G ± 1%  +3.12%          (p=0.008 n=5+5)

Change-Id: I241c4246cdff627d7ecb95cac23060b38f9775ec
Reviewed-on: https://go-review.googlesource.com/34273
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-01-09 22:33:23 +00:00
Robert Griesemer
3d5df64b3f [dev.inline] cmd/compile/internal/syntax: use syntax.Pos for all external positions
- use syntax.Pos in syntax.Error (rather than line, col)
- use syntax.Pos in syntax.PragmaHandler (rather than just line)
- update uses
- better documentation in various places

Also:
- make Pos methods use Pos receiver (rather than *Pos)

Reviewed in and cherry-picked from https://go-review.googlesource.com/#/c/33891/.
With minor adjustments to noder.go to make merge compile.

Change-Id: I5507cea6c2be46a7677087c1aeb69382d31033eb
Reviewed-on: https://go-review.googlesource.com/34236
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-12-09 01:35:14 +00:00
Robert Griesemer
8d20b25779 [dev.inline] cmd/compile/internal/syntax: introduce general position info for nodes
Reviewed in and cherry-picked from https://go-review.googlesource.com/#/c/33758/.
Minor adjustments in noder.go to fix merge.

Change-Id: Ibe429e327c7f8554f8ac205c61ce3738013aed98
Reviewed-on: https://go-review.googlesource.com/34231
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-12-09 00:42:42 +00:00
Robert Griesemer
82d0caea2c [dev.inline] cmd/internal/src: make Pos implementation abstract
Adjust cmd/compile accordingly.

This will make it easier to replace the underlying implementation.

Change-Id: I33645850bb18c839b24785b6222a9e028617addb
Reviewed-on: https://go-review.googlesource.com/34133
Reviewed-by: David Lazar <lazard@golang.org>
2016-12-08 21:31:28 +00:00
Robert Griesemer
24597c080b [dev.inline] cmd/compile: introduce cmd/internal/src.Pos type for line numbers
This is a step toward chosing a different position representation.
By introducing an explicit type, it will be easier to make the
transition step-wise while ensuring everything keeps running.

This has been reviewed via https://go-review.googlesource.com/#/c/34025/.

Change-Id: Ibceddcd62d8f346321ac3250e3940e9c436ed684
Reviewed-on: https://go-review.googlesource.com/34132
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Lazar <lazard@golang.org>
2016-12-08 21:26:25 +00:00
Josh Bleecher Snyder
5af7553f9d cmd/compile: ensure that knownFormats is up to date
Change-Id: I4febdddfe5be569a8bba0a4cddf52dec7f1be1bf
Reviewed-on: https://go-review.googlesource.com/32930
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-11-09 00:21:04 +00:00
Russ Cox
15040c11b9 cmd/dist: copy needed packages from standard library during bootstrap
This allows use of newer math/big (and later debug/pe)
without maintaining a vendored copy somewhere in cmd.

Use for math/big, deleting cmd/compile/internal/big.

Change-Id: I2bffa7a9ef115015be29fafdb02acc3e7a665d11
Reviewed-on: https://go-review.googlesource.com/31010
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-10-17 15:22:11 +00:00