Commit graph

169 commits

Author SHA1 Message Date
Richard Musiol
3b137dd2df cmd/compile: add wasm architecture
This commit adds the wasm architecture to the compile command.
A later commit will contain the corresponding linker changes.

Design doc: https://docs.google.com/document/d/131vjr4DH6JFnb-blm_uRdaC0_Nv3OUwjEY5qVCxCup4

The following files are generated:
- src/cmd/compile/internal/ssa/opGen.go
- src/cmd/compile/internal/ssa/rewriteWasm.go
- src/cmd/internal/obj/wasm/anames.go

Updates #18892

Change-Id: Ifb4a96a3e427aac2362a1c97967d5667450fba3b
Reviewed-on: https://go-review.googlesource.com/103295
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-05-04 17:56:12 +00:00
Matthew Dempsky
eec8fb5ef3 cmd/compile: explicitly disallow mixing -iexport={false,true}
flagiexport currently controls not just whether to use the indexed
export format when writing out package data, but also how symbol
import logic works. In particular, it enables lazy loading logic that
currently doesn't work with packages imported via bimport.

We could change the import logic to base decisions on the export data
format used by the packages that individual symbols were loaded from,
but since we expect to deprecate and remove bimport anyway and there's
no need for mixing bimport and iimport, it's simpler to just disallow
mixing them.

Change-Id: I02dbac45062e9dd85a1a647ee46bfa0efbb67e9d
Reviewed-on: https://go-review.googlesource.com/110715
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-05-01 22:31:24 +00:00
Matthew Dempsky
a3c75d9b31 cmd/compile: enable indexed export format by default
Change-Id: Id018eeb79afbe2c695a583b3845cfbc1aab08388
Reviewed-on: https://go-review.googlesource.com/106797
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-04-24 01:06:17 +00:00
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
dd71e3fef4 cmd/compile: refactor how declarations are imported
This CL moves all of the logic for wiring up imported declarations
into export.go, so that it can be reused by the indexed importer
code. While here, increase symmetry across routines.

Passes toolstash-check.

Change-Id: I1ccec5c3999522b010e4d04ed56b632fd4d712d9
Reviewed-on: https://go-review.googlesource.com/107621
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-04-20 21:19:17 +00:00
Matthew Dempsky
9419713528 cmd/compile: cleanup import logic slightly
Use bio.Reader. Include newline character in the expected string value
instead of truncating it. Get rid of weird "empty archive" check.

Passes toolstash-check.

Change-Id: I16e42542db4827e6ee3644b9a5540a4a30b9bc41
Reviewed-on: https://go-review.googlesource.com/107620
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-04-17 23:48:09 +00:00
Matthew Dempsky
bf10166264 cmd/compile: use empty package name for runtime/{race,msan}
These fake imports are just so we can emit build dependencies for the
linker, so the package name isn't really necessary. Also, the package
import logic assumes that if we have the name for a package, then
we've already read some package data for it.

Using the empty string allows the importers to correctly populate it
the first time these packages are seen in package export data.

Passes toolstash-check.

Change-Id: I047bde297600e9dc07478fccc3f57ccc75ce8ae4
Reviewed-on: https://go-review.googlesource.com/107619
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-04-17 23:47:35 +00:00
Matthew Dempsky
07029254a0 cmd/compile: add package height to export data
A package's height is defined as the length of the longest import path
between itself and a leaf package (i.e., package with no imports).

We can't rely on knowing the path of the package being compiled, so
package height is useful for defining a package ordering.

Updates #24693.

Change-Id: I965162c440b6c5397db91b621ea0be7fa63881f1
Reviewed-on: https://go-review.googlesource.com/105038
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-04-09 23:36:46 +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
Matthew Dempsky
562a199961 cmd/compile: extract inline related fields into separate Inline type
Inl, Inldcl, and InlCost are only applicable to functions with bodies
that can be inlined, so pull them out into a separate Inline type to
make understanding them easier.

A side benefit is that we can check if a function can be inlined by
just checking if n.Func.Inl is non-nil, which simplifies handling of
empty function bodies.

While here, remove some unnecessary Curfn twiddling, and make imported
functions use Inl.Dcl instead of Func.Dcl for consistency for local
functions.

Passes toolstash-check.

Change-Id: Ifd4a80349d85d9e8e4484952b38ec4a63182e81f
Reviewed-on: https://go-review.googlesource.com/104756
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-04-05 05:12:36 +00:00
Matthew Dempsky
c0841ecd87 cmd/compile: disable instrumentation for no-race packages earlier
Rather than checking for each function whether the package supports
instrumentation, check once up front.

Relatedly, tweak the logic for preventing inlining calls to runtime
functions from instrumented packages. Previously, we simply disallowed
inlining runtime functions altogether when instrumenting. With this
CL, it's only disallowed from packages that are actually being
instrumented. That is, now intra-runtime calls can be inlined.

Updates #19054.

Change-Id: I88c97b48bf70193a8a3ee18d952dcb26b0369d55
Reviewed-on: https://go-review.googlesource.com/102815
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-04-02 21:50:05 +00:00
Josh Bleecher Snyder
fa3e9d27f3 cmd/compile: compile all functions concurrently
CL 40693 added concurrent backend compilation support,
and used it for user-provided functions.
Autogenerated functions were still compiled serially.
This CL brings them into the fold.
As of this CL, when requested,
no functions are compiled serially.

There generally aren't many autogenerated functions.
When there are, this CL can help a lot,
because autogenerated functions are usually short.
Many short functions is the best case scenario
for concurrent compilation; see CL 41192.

One example of such a package comes from Dave Cheney's benchjuju:
github.com/juju/govmomi/vim25/types.
It has thousands of autogenerated functions.
This CL improves performance on the entire benchmark
by around a second on my machine at c=8, or about ~5%.

Updates #15756

Change-Id: Ia21e302b2469a9ed743df02244ec7ebde55b32f3
Reviewed-on: https://go-review.googlesource.com/41503
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-03-30 21:38:50 +00:00
David Chase
f7404974da cmd/compile: finish GOEXPERIMENT=preemptibleloops repair
A newish check for branch-likely on single-successor blocks
caught a case where the preemption-check inserter was
setting "likely" on an unconditional branch.

Fixed by checking for that case before setting likely.

Also removed an overconservative restriction on parallel
compilation for GOEXPERIMENT=preemptibleloops; it works
fine, it is just another control-flow transformation.

Change-Id: I8e786e6281e0631cac8d80cff67bfb6402b4d225
Reviewed-on: https://go-review.googlesource.com/102317
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2018-03-26 17:44:14 +00:00
Matthew Dempsky
ea668e18a6 cmd/compile: always write pack files
By always writing out pack files, the object file format can be
simplified somewhat. In particular, the export data format will no
longer require escaping, because the pack file provides appropriate
framing.

This CL does not affect build systems that use -pack, which includes
all major Go build systems (cmd/go, gb, bazel).

Also, existing package import logic already distinguishes pack/object
files based on file contents rather than file extension.

The only exception is cmd/pack, which specially handled object files
created by cmd/compile when used with the 'c' mode. This mode is
extended to now recognize the pack files produced by cmd/compile and
handle them as before.

Passes toolstash-check.

Updates #21705.
Updates #24512.

Change-Id: Idf131013bfebd73a5cde7e087eb19964503a9422
Reviewed-on: https://go-review.googlesource.com/102236
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-03-24 00:51:24 +00:00
David Chase
b30bf958da cmd/compile: enable scopes unconditionally
This revives Alessandro Arzilli's CL to enable scopes
whenever any dwarf is emitted (with optimization or not),
adds a test that detects this changes and shows that it
creates more truthful debugging output.

Reverted change to ssa/debug_test tests made when
scopes were disabled during dwarflocationlist development.

Also included are updates to the Delve test output (it
had fallen out of sync; creating test output for one
updates it for all) and minor naming changes in
ssa/debug_test.

Compile-time/space changes (relative to tip including dwarflocationlists):

benchstat -geomean after.log scopes.log
name        old time/op     new time/op     delta
Template        182ms ± 1%      182ms ± 1%    ~     (p=0.666 n=9+9)
Unicode        82.8ms ± 1%     86.6ms ±14%    ~     (p=0.211 n=9+10)
GoTypes         611ms ± 1%      616ms ± 2%  +0.97%  (p=0.001 n=10+9)
Compiler        2.95s ± 1%      2.95s ± 0%    ~     (p=0.573 n=10+8)
SSA             6.70s ± 1%      6.81s ± 1%  +1.68%  (p=0.000 n=9+10)
Flate           117ms ± 1%      118ms ± 1%  +0.60%  (p=0.036 n=9+8)
GoParser        145ms ± 1%      145ms ± 1%    ~     (p=1.000 n=9+9)
Reflect         398ms ± 1%      396ms ± 1%    ~     (p=0.053 n=9+10)
Tar             171ms ± 1%      171ms ± 1%    ~     (p=0.356 n=9+10)
XML             214ms ± 1%      214ms ± 1%    ~     (p=0.605 n=9+9)
StdCmd          12.4s ± 2%      12.4s ± 1%    ~     (p=1.000 n=9+9)
[Geo mean]      506ms           509ms       +0.71%

name        old user-ns/op  new user-ns/op  delta
Template         254M ± 4%       249M ± 6%    ~     (p=0.155 n=10+10)
Unicode          121M ±11%       124M ± 6%    ~     (p=0.516 n=10+10)
GoTypes          824M ± 2%       869M ± 5%  +5.49%  (p=0.001 n=8+10)
Compiler        4.01G ± 2%      4.02G ± 1%    ~     (p=0.561 n=9+9)
SSA             10.0G ± 2%      10.2G ± 2%  +2.29%  (p=0.000 n=9+10)
Flate            154M ± 7%       154M ± 7%    ~     (p=0.960 n=10+9)
GoParser         190M ± 7%       196M ± 6%    ~     (p=0.064 n=9+10)
Reflect          528M ± 2%       517M ± 3%  -1.97%  (p=0.025 n=10+10)
Tar              227M ± 5%       232M ± 3%    ~     (p=0.061 n=9+10)
XML              286M ± 4%       283M ± 4%    ~     (p=0.343 n=9+9)
[Geo mean]       502M            508M       +1.09%

name        old text-bytes  new text-bytes  delta
HelloSize        672k ± 0%       672k ± 0%  +0.01%  (p=0.000 n=10+10)
CmdGoSize       7.21M ± 0%      7.21M ± 0%  -0.00%  (p=0.000 n=10+10)
[Geo mean]      2.20M           2.20M       +0.00%

name        old data-bytes  new data-bytes  delta
HelloSize       9.88k ± 0%      9.88k ± 0%    ~     (all equal)
CmdGoSize        248k ± 0%       248k ± 0%    ~     (all equal)
[Geo mean]      49.5k           49.5k       +0.00%

name        old bss-bytes   new bss-bytes   delta
HelloSize        125k ± 0%       125k ± 0%    ~     (all equal)
CmdGoSize        144k ± 0%       144k ± 0%  -0.04%  (p=0.000 n=10+10)
[Geo mean]       135k            135k       -0.02%

name        old exe-bytes   new exe-bytes   delta
HelloSize       1.30M ± 0%      1.34M ± 0%  +3.15%  (p=0.000 n=10+10)
CmdGoSize       13.5M ± 0%      13.9M ± 0%  +2.70%  (p=0.000 n=10+10)
[Geo mean]      4.19M           4.31M       +2.92%

Change-Id: Id53b8d57bd00440142ccbd39b95710e14e083fb5
Reviewed-on: https://go-review.googlesource.com/101217
Reviewed-by: Heschi Kreinick <heschi@google.com>
2018-03-16 20:25:10 +00:00
David Chase
1c24ffbf93 cmd/compile: turn on DWARF locations lists for ssa vars
This changes the default setting for -dwarflocationlists
from false to true, removes the flag from ssa/debug_test.go,
and updates runtime/runtime-gdb_test.go to match a change
in debugging output for composite variables.

Current benchmarks (perflock, -count 10)

benchstat -geomean before.log after.log
name        old time/op     new time/op     delta
Template        175ms ± 0%      182ms ± 1%   +3.68%  (p=0.000 n=8+9)
Unicode        82.0ms ± 2%     82.8ms ± 1%   +0.96%  (p=0.019 n=9+9)
GoTypes         590ms ± 1%      611ms ± 1%   +3.42%  (p=0.000 n=9+10)
Compiler        2.85s ± 0%      2.95s ± 1%   +3.60%  (p=0.000 n=9+10)
SSA             6.42s ± 1%      6.70s ± 1%   +4.31%  (p=0.000 n=10+9)
Flate           113ms ± 2%      117ms ± 1%   +3.11%  (p=0.000 n=10+9)
GoParser        140ms ± 1%      145ms ± 1%   +3.47%  (p=0.000 n=10+9)
Reflect         384ms ± 0%      398ms ± 1%   +3.56%  (p=0.000 n=8+9)
Tar             165ms ± 1%      171ms ± 1%   +3.33%  (p=0.000 n=9+9)
XML             207ms ± 2%      214ms ± 1%   +3.41%  (p=0.000 n=9+9)
StdCmd          11.8s ± 2%      12.4s ± 2%   +4.41%  (p=0.000 n=10+9)
[Geo mean]      489ms           506ms        +3.38%

name        old user-ns/op  new user-ns/op  delta
Template         247M ± 4%       254M ± 4%   +2.76%  (p=0.040 n=10+10)
Unicode          118M ±16%       121M ±11%     ~     (p=0.364 n=10+10)
GoTypes          805M ± 2%       824M ± 2%   +2.37%  (p=0.003 n=9+8)
Compiler        3.92G ± 2%      4.01G ± 2%   +2.20%  (p=0.001 n=9+9)
SSA             9.63G ± 4%     10.00G ± 2%   +3.81%  (p=0.000 n=10+9)
Flate            155M ±10%       154M ± 7%     ~     (p=0.718 n=9+10)
GoParser         184M ±11%       190M ± 7%     ~     (p=0.220 n=10+9)
Reflect          506M ± 4%       528M ± 2%   +4.27%  (p=0.000 n=10+10)
Tar              224M ± 4%       227M ± 5%     ~     (p=0.207 n=10+9)
XML              272M ± 7%       286M ± 4%   +5.23%  (p=0.010 n=10+9)
[Geo mean]       489M            502M        +2.76%

name        old text-bytes  new text-bytes  delta
HelloSize        672k ± 0%       672k ± 0%     ~     (all equal)
CmdGoSize       7.21M ± 0%      7.21M ± 0%     ~     (all equal)
[Geo mean]      2.20M           2.20M        +0.00%

name        old data-bytes  new data-bytes  delta
HelloSize       9.88k ± 0%      9.88k ± 0%     ~     (all equal)
CmdGoSize        248k ± 0%       248k ± 0%     ~     (all equal)
[Geo mean]      49.5k           49.5k        +0.00%

name        old bss-bytes   new bss-bytes   delta
HelloSize        125k ± 0%       125k ± 0%     ~     (all equal)
CmdGoSize        144k ± 0%       144k ± 0%     ~     (all equal)
[Geo mean]       135k            135k        +0.00%

name        old exe-bytes   new exe-bytes   delta
HelloSize       1.10M ± 0%      1.30M ± 0%  +17.82%  (p=0.000 n=10+10)
CmdGoSize       11.6M ± 0%      13.5M ± 0%  +16.90%  (p=0.000 n=10+10)
[Geo mean]      3.57M           4.19M       +17.36%

Change-Id: I250055813cadd25cebee8da1f9a7f995a6eae432
Reviewed-on: https://go-review.googlesource.com/100738
Reviewed-by: Heschi Kreinick <heschi@google.com>
2018-03-15 21:34:17 +00:00
Heschi Kreinick
7d7af6106f cmd/compile/internal: decouple scope tracking from location lists
We're trying to enable location lists by default, and it's easier to do
that if we don't have to worry about scope tracking at the same time.
We can evaluate their performance impact separately.

However, that does mean that "err" is ambiguous in the test case, so
rename it to err2 for now.

Change-Id: I24f119016185c52b7d9affc74207f6a5b450fb6f
Reviewed-on: https://go-review.googlesource.com/89355
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2018-02-14 18:29:18 +00:00
Daniel Martí
7ddd467ef3 cmd/compile: print usage to stderr for consistency
All the other tools and commands print the usage text to standard error.
"go tool compile" was the odd one out, so fix it.

While at it, make objabi.Flagprint a bit more Go-like with an io.Writer
instead of a file descriptor, which is likely a leftover from the C
days.

Fixes #23234.

Change-Id: I9abf2e79461e61c8c8bfaee2c6bf8faf26e0e6c3
Reviewed-on: https://go-review.googlesource.com/85418
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-13 21:11:55 +00:00
Austin Clements
2010189407 runtime: remove legacy eager write barrier
Now that the buffered write barrier is implemented for all
architectures, we can remove the old eager write barrier
implementation. This CL removes the implementation from the runtime,
support in the compiler for calling it, and updates some compiler
tests that relied on the old eager barrier support. It also makes sure
that all of the useful comments from the old write barrier
implementation still have a place to live.

Fixes #22460.

Updates #21640 since this fixes the layering concerns of the write
barrier (but not the other things in that issue).

Change-Id: I580f93c152e89607e0a72fe43370237ba97bae74
Reviewed-on: https://go-review.googlesource.com/92705
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-02-13 16:34:46 +00:00
Austin Clements
2ae1e1ae2f runtime: buffered write barrier for s390x
Updates #22460.

Change-Id: I3f793e69577c1b837ad2666e6209a97a452405d4
Reviewed-on: https://go-review.googlesource.com/92703
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-13 16:34:24 +00:00
Austin Clements
ae7d5f84f8 runtime: buffered write barrier for ppc64
Updates #22460.

Change-Id: I6040c4024111c80361c81eb7eec5071ec9efb4f9
Reviewed-on: https://go-review.googlesource.com/92702
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-13 16:34:23 +00:00
Austin Clements
313a4b2b7f runtime: buffered write barrier for mips
Updates #22460.

Change-Id: Ieaca94385c3bb88dcc8351c3866b4b0e2a1412b5
Reviewed-on: https://go-review.googlesource.com/92701
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-13 16:34:21 +00:00
Austin Clements
a39de96438 runtime: buffered write barrier for mips64
Updates #22460.

Change-Id: I9718bff3a346e765601cfd1890417bdfa0f7b9d8
Reviewed-on: https://go-review.googlesource.com/92700
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-13 16:34:20 +00:00
Austin Clements
79594ee95a runtime: buffered write barrier for arm64
Updates #22460.

Change-Id: I5f8fbece9545840f5fc4c9834e2050b0920776f0
Reviewed-on: https://go-review.googlesource.com/92699
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-13 16:34:19 +00:00
Austin Clements
1de1f316df runtime: buffered write barrier for arm
Updates #22460.

Change-Id: I5581df7ad553237db7df3701b117ad99e0593b78
Reviewed-on: https://go-review.googlesource.com/92698
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-02-13 16:34:17 +00:00
Austin Clements
24dd83d7eb runtime: buffered write barrier for amd64p32
Updates #22460.

Change-Id: I6656d478625e5e54aa2eaa38d99dfb0f71ea1fdd
Reviewed-on: https://go-review.googlesource.com/92697
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-13 16:34:16 +00:00
Austin Clements
252f1170e5 runtime: buffered write barrier for 386
Updates #22460.

Change-Id: I3c8e90fd6bcda7e28911036591873d63665aaca7
Reviewed-on: https://go-review.googlesource.com/92696
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-13 16:34:15 +00:00
Matthew Dempsky
bd983a6d2e cmd/compile: fix GOEXPERIMENT checks
GOEXPERIMENT is only set during make.bash, so checking the environment
variable isn't effectual. Instead, check the values exposed by objabi.

These experiments look potentially safe, but it seems too late in the
release cycle to try to assuage that. The one exception is frame
pointer experiment, which is trivially safe: it just amounts to
incrementing some stack offsets by PtrSize.

Fixes #22223.

Change-Id: I46dc7c54b1347143d02d6b9635038230cda6d164
Reviewed-on: https://go-review.googlesource.com/80760
Reviewed-by: Russ Cox <rsc@golang.org>
2017-12-01 00:40:45 +00:00
Vladimir Stefanovic
6be1c09e19 cmd/compile: use soft-float routines for soft-float targets
Updates #18162 (mostly fixes)

Change-Id: I35bcb8a688bdaa432adb0ddbb73a2f7adda47b9e
Reviewed-on: https://go-review.googlesource.com/37958
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-11-30 17:37:37 +00:00
Than McIntosh
4435fcfd6c compiler,linker: support for DWARF inlined instances
Compiler and linker changes to support DWARF inlined instances,
see https://go.googlesource.com/proposal/+/HEAD/design/22080-dwarf-inlining.md
for design details.

This functionality is gated via the cmd/compile option -gendwarfinl=N,
where N={0,1,2}, where a value of 0 disables dwarf inline generation,
a value of 1 turns on dwarf generation without tracking of formal/local
vars from inlined routines, and a value of 2 enables inlines with
variable tracking.

Updates #22080

Change-Id: I69309b3b815d9fed04aebddc0b8d33d0dbbfad6e
Reviewed-on: https://go-review.googlesource.com/75550
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-11-30 14:39:19 +00:00
Keith Randall
5419ed3a66 cmd/compile: remove unused code
Found a few functions in cmd/compile that aren't used.

Change-Id: I53957dae6f1a645feb8b95383f0f050964b4f7d4
Reviewed-on: https://go-review.googlesource.com/79975
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-11-27 16:48:28 +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
griesemer
ca2a886cba cmd/compile: record original and absolute file names for line directives
Also, with this change, error locations don't print absolute positions
in [] brackets following positions relative to line directives. To get
the absolute positions as well, specify the -L flag.

Fixes #22660.

Change-Id: I9ecfa254f053defba9c802222874155fa12fee2c
Reviewed-on: https://go-review.googlesource.com/77090
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2017-11-13 16:47:41 +00:00
griesemer
25159d3af9 cmd/compile: avoid spurious errors for invalid map key types
Instead of trying to validate map key types eagerly in some
cases, delay their validation to the end of type-checking,
when we all type information is present.

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

Fixes #21273.
Fixes #21657.

Change-Id: I532369dc91c6adca1502d6aa456bb06b57e6c7ff
Reviewed-on: https://go-review.googlesource.com/75310
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-11-02 23:53:38 +00:00
Austin Clements
7e343134d3 cmd/compile: compiler support for buffered write barrier
This CL implements the compiler support for calling the buffered write
barrier added by the previous CL.

Since the buffered write barrier is only implemented on amd64 right
now, this still supports the old, eager write barrier as well. There's
little overhead to supporting both and this way a few tests in
test/fixedbugs that expect to have liveness maps at write barrier
calls can easily opt-in to the old, eager barrier.

This significantly improves the performance of the write barrier:

name             old time/op  new time/op  delta
WriteBarrier-12  73.5ns ±20%  19.2ns ±27%  -73.90%  (p=0.000 n=19+18)

It also reduces the size of binaries because the write barrier call is
more compact:

name        old object-bytes  new object-bytes  delta
Template           398k ± 0%         393k ± 0%  -1.14%  (p=0.008 n=5+5)
Unicode            208k ± 0%         206k ± 0%  -1.00%  (p=0.008 n=5+5)
GoTypes           1.18M ± 0%        1.15M ± 0%  -2.00%  (p=0.008 n=5+5)
Compiler          4.05M ± 0%        3.88M ± 0%  -4.26%  (p=0.008 n=5+5)
SSA               8.25M ± 0%        8.11M ± 0%  -1.59%  (p=0.008 n=5+5)
Flate              228k ± 0%         224k ± 0%  -1.83%  (p=0.008 n=5+5)
GoParser           295k ± 0%         284k ± 0%  -3.62%  (p=0.008 n=5+5)
Reflect           1.00M ± 0%        0.99M ± 0%  -0.70%  (p=0.008 n=5+5)
Tar                339k ± 0%         333k ± 0%  -1.67%  (p=0.008 n=5+5)
XML                404k ± 0%         395k ± 0%  -2.10%  (p=0.008 n=5+5)
[Geo mean]         704k              690k       -2.00%

name        old exe-bytes     new exe-bytes     delta
HelloSize         1.05M ± 0%        1.04M ± 0%  -1.55%  (p=0.008 n=5+5)

https://perf.golang.org/search?q=upload:20171027.1

(Amusingly, this also reduces compiler allocations by 0.75%, which,
combined with the better write barrier, speeds up the compiler overall
by 2.10%. See the perf link.)

It slightly improves the performance of most of the go1 benchmarks and
improves the performance of the x/benchmarks:

name                      old time/op    new time/op    delta
BinaryTree17-12              2.40s ± 1%     2.47s ± 1%  +2.69%  (p=0.000 n=19+19)
Fannkuch11-12                2.95s ± 0%     2.95s ± 0%  +0.21%  (p=0.000 n=20+19)
FmtFprintfEmpty-12          41.8ns ± 4%    41.4ns ± 2%  -1.03%  (p=0.014 n=20+20)
FmtFprintfString-12         68.7ns ± 2%    67.5ns ± 1%  -1.75%  (p=0.000 n=20+17)
FmtFprintfInt-12            79.0ns ± 3%    77.1ns ± 1%  -2.40%  (p=0.000 n=19+17)
FmtFprintfIntInt-12          127ns ± 1%     123ns ± 3%  -3.42%  (p=0.000 n=20+20)
FmtFprintfPrefixedInt-12     152ns ± 1%     150ns ± 1%  -1.02%  (p=0.000 n=18+17)
FmtFprintfFloat-12           211ns ± 1%     209ns ± 0%  -0.99%  (p=0.000 n=20+16)
FmtManyArgs-12               500ns ± 0%     496ns ± 0%  -0.73%  (p=0.000 n=17+20)
GobDecode-12                6.44ms ± 1%    6.53ms ± 0%  +1.28%  (p=0.000 n=20+19)
GobEncode-12                5.46ms ± 0%    5.46ms ± 1%    ~     (p=0.550 n=19+20)
Gzip-12                      220ms ± 1%     216ms ± 0%  -1.75%  (p=0.000 n=19+19)
Gunzip-12                   38.8ms ± 0%    38.6ms ± 0%  -0.30%  (p=0.000 n=18+19)
HTTPClientServer-12         79.0µs ± 1%    78.2µs ± 1%  -1.01%  (p=0.000 n=20+20)
JSONEncode-12               11.9ms ± 0%    11.9ms ± 0%  -0.29%  (p=0.000 n=20+19)
JSONDecode-12               52.6ms ± 0%    52.2ms ± 0%  -0.68%  (p=0.000 n=19+20)
Mandelbrot200-12            3.69ms ± 0%    3.68ms ± 0%  -0.36%  (p=0.000 n=20+20)
GoParse-12                  3.13ms ± 1%    3.18ms ± 1%  +1.67%  (p=0.000 n=19+20)
RegexpMatchEasy0_32-12      73.2ns ± 1%    72.3ns ± 1%  -1.19%  (p=0.000 n=19+18)
RegexpMatchEasy0_1K-12       241ns ± 0%     239ns ± 0%  -0.83%  (p=0.000 n=17+16)
RegexpMatchEasy1_32-12      68.6ns ± 1%    69.0ns ± 1%  +0.47%  (p=0.015 n=18+16)
RegexpMatchEasy1_1K-12       364ns ± 0%     361ns ± 0%  -0.67%  (p=0.000 n=16+17)
RegexpMatchMedium_32-12      104ns ± 1%     103ns ± 1%  -0.79%  (p=0.001 n=20+15)
RegexpMatchMedium_1K-12     33.8µs ± 3%    34.0µs ± 2%    ~     (p=0.267 n=20+19)
RegexpMatchHard_32-12       1.64µs ± 1%    1.62µs ± 2%  -1.25%  (p=0.000 n=19+18)
RegexpMatchHard_1K-12       49.2µs ± 0%    48.7µs ± 1%  -0.93%  (p=0.000 n=19+18)
Revcomp-12                   391ms ± 5%     396ms ± 7%    ~     (p=0.154 n=19+19)
Template-12                 63.1ms ± 0%    59.5ms ± 0%  -5.76%  (p=0.000 n=18+19)
TimeParse-12                 307ns ± 0%     306ns ± 0%  -0.39%  (p=0.000 n=19+17)
TimeFormat-12                325ns ± 0%     323ns ± 0%  -0.50%  (p=0.000 n=19+19)
[Geo mean]                  47.3µs         46.9µs       -0.67%

https://perf.golang.org/search?q=upload:20171026.1

name                       old time/op  new time/op  delta
Garbage/benchmem-MB=64-12  2.25ms ± 1%  2.20ms ± 1%  -2.31%  (p=0.000 n=18+18)
HTTP-12                    12.6µs ± 0%  12.6µs ± 0%  -0.72%  (p=0.000 n=18+17)
JSON-12                    11.0ms ± 0%  11.0ms ± 1%  -0.68%  (p=0.000 n=17+19)

https://perf.golang.org/search?q=upload:20171026.2

Updates #14951.
Updates #22460.

Change-Id: Id4c0932890a1d41020071bec73b8522b1367d3e7
Reviewed-on: https://go-review.googlesource.com/73712
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-30 18:12:46 +00:00
Austin Clements
5a4b6bce37 cmd/compile: improve coverage of nowritebarrierrec check
The current go:nowritebarrierrec checker has two problems that limit
its coverage:

1. It doesn't understand that systemstack calls its argument, which
means there are several cases where we fail to detect prohibited write
barriers.

2. It only observes calls in the AST, so calls constructed during
lowering by SSA aren't followed.

This CL completely rewrites this checker to address these issues.

The current checker runs entirely after walk and uses visitBottomUp,
which introduces several problems for checking across systemstack.
First, visitBottomUp itself doesn't understand systemstack calls, so
the callee may be ordered after the caller, causing the checker to
fail to propagate constraints. Second, many systemstack calls are
passed a closure, which is quite difficult to resolve back to the
function definition after transformclosure and walk have run. Third,
visitBottomUp works exclusively on the AST, so it can't observe calls
created by SSA.

To address these problems, this commit splits the check into two
phases and rewrites it to use a call graph generated during SSA
lowering. The first phase runs before transformclosure/walk and simply
records systemstack arguments when they're easy to get. Then, it
modifies genssa to record static call edges at the point where we're
lowering to Progs (which is the latest point at which position
information is conveniently available). Finally, the second phase runs
after all functions have been lowered and uses a direct BFS walk of
the call graph (combining systemstack calls with static calls) to find
prohibited write barriers and construct nice error messages.

Fixes #22384.
For #22460.

Change-Id: I39668f7f2366ab3c1ab1a71eaf25484d25349540
Reviewed-on: https://go-review.googlesource.com/72773
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-10-29 19:36:44 +00:00
Matthew Dempsky
7092a312e5 cmd/compile: replace -l=2 with -d typecheckinl
Currently, benchmarking compile performance under -l=4 is confounded
by -l=2 enabling eager typechecking of unused inline function bodies
for debugging. This isn't logically an "inlining aggressiveness"
level, so instead move this logic under the -d umbrella flag.

Change-Id: I713f68952efbe25b6941d3ebc2f3707ccbbd6240
Reviewed-on: https://go-review.googlesource.com/72253
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-10-22 14:33:53 +00:00
Austin Clements
717d37591d cmd/compile: allow duplicate DWARF producer symbols
When building test binaries, we build one archive with all of the test
sources and a second archive with the generated test package main and
link them together. If the test sources are themselves in package main
and the test was compiled with non-default compiler flags, then both
archives will contain a go.cuinfo.producer.main symbol, leading to a
duplicate symbol failure.

This has been causing test build failures on darwin-arm-a1428ios,
darwin-arm64-a1549ios, linux-amd64-noopt, android-arm-wiko-fever, and
android-arm64-wiko-fever since CL 71430 added this symbol. This CL
should fix the build.

Change-Id: I69051c846e7c0d97395a865a361cae07f411f9ad
Reviewed-on: https://go-review.googlesource.com/71771
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-10-19 02:56:09 +00:00
Austin Clements
2c1d2e06af cmd/compile, cmd/link: record compiler flags in DW_AT_producer
This adds a whitelisted subset of compiler flags to the DW_AT_producer
DWARF attribute of each package compilation unit DIE. This is common
practice in DWARF and can help debuggers determine the quality of the
produced debugging information.

Fixes #22168.

Change-Id: I1b994ef2262aa9b88b68eb6e883695d1103acc58
Reviewed-on: https://go-review.googlesource.com/71430
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-18 19:32:40 +00:00
Keith Randall
e130dcf051 cmd/compile: abort earlier if stack frame too large
If the stack frame is too large, abort immediately.
We used to generate code first, then abort.
In issue 22200, generating code raised a panic
so we got an ICE instead of an error message.

Change the max frame size to 1GB (from 2GB).
Stack frames between 1.1GB and 2GB didn't used to work anyway,
the pcln table generation would have failed and generated an ICE.

Fixes #22200

Change-Id: I1d918ab27ba6ebf5c87ec65d1bccf973f8c8541e
Reviewed-on: https://go-review.googlesource.com/69810
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-11 18:24:13 +00:00
Russ Cox
840f2c167f cmd/asm, cmd/cgo, cmd/compile, cmd/cover, cmd/link: use standard -V output
Also add -V=full to print a unique identifier of the specific tool being invoked.
This will be used for content-based staleness.

Also sort and clean up a few of the flag doc comments.

Change-Id: I786fe50be0b8e5f77af809d8d2dab721185c2abd
Reviewed-on: https://go-review.googlesource.com/68590
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2017-10-06 20:28:40 +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
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
Matthew Dempsky
3124439b3a cmd/compile: make more use of exported position information
Updates #19683.

Change-Id: I64b3b93a3ab14518a5376e1270bdd2a94bdd67ef
Reviewed-on: https://go-review.googlesource.com/59611
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-08-29 15:50:53 +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
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
Russ Cox
f0cf740733 cmd/compile: omit X:framepointer in compile version
Framepointer is the default now. Only print an X: list
if the settings are _not_ the default.

Before:

$ go tool compile -V
compile version devel +a5f30d9508 Sun Jul 16 14:43:48 2017 -0400 X:framepointer
$ go1.8 tool compile -V
compile version go1.8 X:framepointer
$

After:

$ go tool compile -V
compile version devel +a5f30d9508 Sun Jul 16 14:43:48 2017 -0400
$ go1.9 tool compile -V # imagined
compile version go1.9
$

Perpetuates #18317.

Change-Id: I981ba5c62be32e650a166fc9740703122595639b
Reviewed-on: https://go-review.googlesource.com/49252
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-07-17 16:36:49 +00:00
Robert Griesemer
6c2458e72d cmd/compile: permit Unicode spaces in (expanded) package paths
This doesn't change the existing restriction with disallows
spaces in import paths (as found in an import declaration).
It simply permits packages to be under a directory name that
may contain spaces.

Verified manually that it works. This could use a test, but the
change is trivial. We also can't use the existing test framework
(under test/) because the way those tests are run with test/run.go,
the mechanims for compiling a directory, even if it contains blanks
it its name, does't produce compiler paths with blanks
(the compilation is local).

Fixes #20306.

Change-Id: I6cbffb86c3394347897c3c94b110da0aadc5bfdf
Reviewed-on: https://go-review.googlesource.com/46001
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2017-06-19 16:59:58 +00:00
Matthew Dempsky
eb86abaa36 cmd/compile: better error for malformed packages
Fixes #14270.

Change-Id: Iaf2496a24b1aba443391b90951cef472add73f13
Reviewed-on: https://go-review.googlesource.com/45950
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-06-15 21:24:33 +00:00
Keith Randall
a836254d08 cmd/compile: reject unknown //go: comments in std library
Fixes #18331

Change-Id: Ie5c6685be3002533b84604ff1f13f2f0850f29e2
Reviewed-on: https://go-review.googlesource.com/45010
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-06-06 22:28:17 +00:00