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2659 Commits

Author SHA1 Message Date
Alberto Donizetti
e99dafc4a8 cmd/compile: fix misleading "truncated to int" messages
When defining an int const, the compiler tries to cast the RHS
expression to int. The cast may fail for three reasons:

  1. expr is an integer constant that overflows int
  2. expr is a floating point constant
  3. expr is a complex constant, or not a number

In the second case, in order to print a sensible error message, we
must distinguish between a floating point constant that should be
included in the error message and a floating point constant that
cannot be reasonably formatted for inclusion in an error message.

For example, in:

  const a int = 1.1
  const b int = 1 + 1e-100

a is in the former group, while b is in the latter, since the floating
point value resulting from the evaluation of the rhs of the assignment
(1.00...01) is too long to be fully printed in an error message, and
cannot be shortened without making the error message misleading
(rounding or truncating it would result in a "1", which looks like an
integer constant, and it makes little sense in an error message about
an invalid floating point expression).

To fix this problem, we try to format the float value using fconv
(which is used by the error reporting mechanism to format float
arguments), and then parse the resulting string back to a
big.Float. If the result is an integer, we assume that expr is a float
value that cannot be reasonably be formatted as a string, and we emit
an error message that does not include its string representation.

Also, change the error message for overflows to a more conservative
"integer too large", which does not mention overflows that are only
caused by an internal implementation restriction.

Also, change (*Mpint) SetFloat so that it returns a bool (instead of
0/-1 for success/failure).

Fixes #11371

Change-Id: Ibbc73e2ed2eaf41f07827b0649d0eb637150ecaa
Reviewed-on: https://go-review.googlesource.com/35411
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-03-07 19:34:22 +00:00
Robert Griesemer
cf710949a9 Revert "cmd/compile: improve error message if init is directly invoked"
This reverts commit cb6e0639fb.

The fix is incorrect as it's perfectly fine to refer to an
identifier 'init' inside a function, and 'init' may even be
a variable of function value. Misspelling 'init' in that
context would lead to an incorrect error message.

Reopened #8481.

Change-Id: I49787fdf7738213370ae6f0cab54013e9e3394a8
Reviewed-on: https://go-review.googlesource.com/37876
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-06 23:48:37 +00:00
Quentin Smith
4b261a1410 test/fixedbugs: add test for #19403
Change-Id: Ie52dac8eb4daed95e049ad74d5ae101e8a5cb854
Reviewed-on: https://go-review.googlesource.com/37725
Run-TryBot: Quentin Smith <quentin@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-03-06 21:39:00 +00:00
Russ Cox
06a6b3a413 test/locklinear: deflake again
On overloaded machines once we get to big N, the machine slowness dominates.
But we only retry once we get to a big N.
Instead, retry for small N too, and die on the first big N that fails.

Change-Id: I3ab9cfb88832ad86e2ba1389a926045091268aeb
Reviewed-on: https://go-review.googlesource.com/37543
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-06 15:05:42 +00:00
Giovanni Bajo
4fc45ae879 cmd/compile: improve generic rules for BCE based on AND operations.
Match more patterns generated by the compiler where the index for
a bound check is bounded through a AND operation, with different
register sizes.

These rules trigger a dozen of times in a bootstrap.

Change-Id: Ic9fff16f21d08580f19a366c3ee1a372e58357d1
Reviewed-on: https://go-review.googlesource.com/37442
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-03-04 16:13:07 +00:00
David Lazar
1c6ef9aeed cmd/compile: copy literals when inlining
Without this, literals keep their original source positions through
inlining, which results in strange jumps in line numbers of inlined
function bodies. By copying literals, inlining can update their source
position like other nodes.

Fixes #15453.

Change-Id: Iad5d9bbfe183883794213266dc30e31bab89ee69
Reviewed-on: https://go-review.googlesource.com/37232
Run-TryBot: David Lazar <lazard@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
2017-03-03 21:29:32 +00:00
Josh Bleecher Snyder
04fc887761 runtime: delay marking maps as writing until after first alg call
Fixes #19359

Change-Id: I196b47cf0471915b6dc63785e8542aa1876ff695
Reviewed-on: https://go-review.googlesource.com/37665
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-03-02 17:38:30 +00:00
Matthew Dempsky
0ee9c46cb1 cmd/compile: add missing WBs for reflect.{Slice,String}Header.Data
Fixes #19168.

Change-Id: I3f4fcc0b189c53819ac29ef8de86fdad76a17488
Reviewed-on: https://go-review.googlesource.com/37663
Reviewed-by: Keith Randall <khr@golang.org>
2017-03-02 17:21:50 +00:00
Josh Bleecher Snyder
542a60fbde cmd/compile: don't crash when slicing non-slice
Fixes #19323

Change-Id: I92d1bdefb15de6178a577a4fa0f0dc004f791904
Reviewed-on: https://go-review.googlesource.com/37584
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-02 15:48:19 +00:00
Matthew Dempsky
b6c600fc9a cmd/compile/internal/gc: separate builtin and real runtime packages
The builtin runtime package definitions intentionally diverge from the
actual runtime package's, but this only works as long as they never
overlap.

To make it easier to expand the builtin runtime package, this CL now
loads their definitions into a logically separate "go.runtime"
package.  By resetting the package's Prefix field to "runtime", any
references to builtin definitions will still resolve against the real
package runtime.

Fixes #14482.

Passes toolstash -cmp.

Change-Id: I539c0994deaed4506a331f38c5b4d6bc8c95433f
Reviewed-on: https://go-review.googlesource.com/37538
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-03-01 01:06:32 +00:00
philhofer
379567aad1 cmd/compile/ssa: more aggressive constant folding
Add rewrite rules that canonicalize the location
of constants in expressions, and fold conststants
that appear in operations that can be trivially
reassociated.

After this change, the compiler constant-folds
expressions like "4 + x - 1" and "4 & x & 1"

Benchmarks affected on darwin/amd64:

name                     old time/op    new time/op    delta
FmtFprintfInt-8            82.1ns ± 1%    81.7ns ± 1%  -0.46%  (p=0.023 n=8+9)
FmtFprintfIntInt-8          122ns ± 2%     120ns ± 2%  -1.48%  (p=0.047 n=10+10)
FmtManyArgs-8               493ns ± 0%     486ns ± 1%  -1.37%  (p=0.000 n=8+10)
Gzip-8                      230ms ± 0%     229ms ± 1%  -0.46%  (p=0.001 n=10+9)
HTTPClientServer-8         74.5µs ± 1%    73.7µs ± 1%  -1.11%  (p=0.000 n=10+10)
JSONDecode-8               51.7ms ± 0%    51.9ms ± 1%  +0.42%  (p=0.017 n=10+9)
RegexpMatchEasy0_32-8      82.6ns ± 1%    81.7ns ± 0%  -1.02%  (p=0.000 n=9+8)
RegexpMatchMedium_32-8      121ns ± 1%     120ns ± 1%  -1.48%  (p=0.001 n=10+10)
Revcomp-8                   426ms ± 1%     400ms ± 1%  -6.16%  (p=0.000 n=10+10)
TimeFormat-8                330ns ± 1%     327ns ± 0%  -0.82%  (p=0.000 n=10+10)

name                     old speed      new speed      delta
Gzip-8                   84.4MB/s ± 0%  84.8MB/s ± 1%  +0.47%  (p=0.001 n=10+9)
JSONDecode-8             37.6MB/s ± 0%  37.4MB/s ± 1%  -0.42%  (p=0.016 n=10+9)
RegexpMatchEasy0_32-8     387MB/s ± 1%   392MB/s ± 0%  +1.06%  (p=0.000 n=9+8)
RegexpMatchMedium_32-8   8.21MB/s ± 1%  8.34MB/s ± 1%  +1.58%  (p=0.000 n=10+9)
Revcomp-8                 597MB/s ± 1%   636MB/s ± 1%  +6.57%  (p=0.000 n=10+10)

Change-Id: Ie37ff91605b76a984a8400dfd1e34f50bf61c864
Reviewed-on: https://go-review.googlesource.com/37290
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-28 20:25:33 +00:00
Josh Bleecher Snyder
504bc3ed24 cmd/compile, runtime: specialize convT2x, don't alloc for zero vals
Prior to this CL, all runtime conversions
from a concrete value to an interface went
through one of two runtime calls: convT2E or convT2I.
However, in practice, basic types are very common.
Specializing convT2x for those basic types allows
for a more efficient implementation for those types.
For basic scalars and strings, allocation and copying
can use the same methods as normal code.
For pointer-free types, allocation can occur without
zeroing, and copying can take place without GC calls.
For slices, copying is cheaper and simpler.

This CL adds twelve runtime routines:

convT2E16, convT2I16
convT2E32, convT2I32
convT2E64, convT2I64
convT2Estring, convT2Istring
convT2Eslice, convT2Islice
convT2Enoptr, convT2Inoptr

While compiling make.bash, 93% of all convT2x calls
are now to one of these specialized convT2x call.

Within specialized convT2x routines, it is cheap to check
for a zero value, in a way that it is not in general.
When we detect a zero value there, we return a pointer
to zeroVal, rather than allocating.

name                         old time/op  new time/op  delta
ConvT2Ezero/zero/16-8        17.9ns ± 2%   3.0ns ± 3%  -83.20%  (p=0.000 n=56+56)
ConvT2Ezero/zero/32-8        17.8ns ± 2%   3.0ns ± 3%  -83.15%  (p=0.000 n=59+60)
ConvT2Ezero/zero/64-8        20.1ns ± 1%   3.0ns ± 2%  -84.98%  (p=0.000 n=57+57)
ConvT2Ezero/zero/str-8       32.6ns ± 1%   3.0ns ± 4%  -90.70%  (p=0.000 n=59+60)
ConvT2Ezero/zero/slice-8     36.7ns ± 2%   3.0ns ± 2%  -91.78%  (p=0.000 n=59+59)
ConvT2Ezero/zero/big-8       91.9ns ± 2%  85.9ns ± 2%   -6.52%  (p=0.000 n=57+57)
ConvT2Ezero/nonzero/16-8     17.7ns ± 2%  12.7ns ± 3%  -28.38%  (p=0.000 n=55+60)
ConvT2Ezero/nonzero/32-8     17.8ns ± 1%  12.7ns ± 1%  -28.44%  (p=0.000 n=54+57)
ConvT2Ezero/nonzero/64-8     20.0ns ± 1%  15.0ns ± 1%  -24.90%  (p=0.000 n=56+58)
ConvT2Ezero/nonzero/str-8    32.6ns ± 1%  25.7ns ± 1%  -21.17%  (p=0.000 n=58+55)
ConvT2Ezero/nonzero/slice-8  36.8ns ± 2%  30.4ns ± 1%  -17.32%  (p=0.000 n=60+52)
ConvT2Ezero/nonzero/big-8    92.1ns ± 2%  85.9ns ± 2%   -6.70%  (p=0.000 n=57+59)

Benchmarks on a real program (the compiler):

name       old time/op      new time/op      delta
Template        227ms ± 5%       221ms ± 2%  -2.48%  (p=0.000 n=30+26)
Unicode         102ms ± 5%       100ms ± 3%  -1.30%  (p=0.009 n=30+26)
GoTypes         656ms ± 5%       659ms ± 4%    ~     (p=0.208 n=30+30)
Compiler        2.82s ± 2%       2.82s ± 1%    ~     (p=0.614 n=29+27)
Flate           128ms ± 2%       128ms ± 5%    ~     (p=0.783 n=27+28)
GoParser        158ms ± 3%       158ms ± 3%    ~     (p=0.261 n=28+30)
Reflect         408ms ± 7%       401ms ± 3%    ~     (p=0.075 n=30+30)
Tar             123ms ± 6%       121ms ± 8%    ~     (p=0.287 n=29+30)
XML             220ms ± 2%       220ms ± 4%    ~     (p=0.805 n=29+29)

name       old user-ns/op   new user-ns/op   delta
Template   281user-ms ± 4%  279user-ms ± 3%  -0.87%  (p=0.044 n=28+28)
Unicode    142user-ms ± 4%  141user-ms ± 3%  -1.04%  (p=0.015 n=30+27)
GoTypes    884user-ms ± 3%  886user-ms ± 2%    ~     (p=0.532 n=30+30)
Compiler   3.94user-s ± 3%  3.92user-s ± 1%    ~     (p=0.185 n=30+28)
Flate      165user-ms ± 2%  165user-ms ± 4%    ~     (p=0.780 n=27+29)
GoParser   209user-ms ± 2%  208user-ms ± 3%    ~     (p=0.453 n=28+30)
Reflect    533user-ms ± 6%  526user-ms ± 3%    ~     (p=0.057 n=30+30)
Tar        156user-ms ± 6%  154user-ms ± 6%    ~     (p=0.133 n=29+30)
XML        288user-ms ± 4%  288user-ms ± 4%    ~     (p=0.633 n=30+30)

name       old alloc/op     new alloc/op     delta
Template       41.0MB ± 0%      40.9MB ± 0%  -0.11%  (p=0.000 n=29+29)
Unicode        32.6MB ± 0%      32.6MB ± 0%    ~     (p=0.572 n=29+30)
GoTypes         122MB ± 0%       122MB ± 0%  -0.10%  (p=0.000 n=30+30)
Compiler        482MB ± 0%       481MB ± 0%  -0.07%  (p=0.000 n=30+29)
Flate          26.6MB ± 0%      26.6MB ± 0%    ~     (p=0.096 n=30+30)
GoParser       32.7MB ± 0%      32.6MB ± 0%  -0.06%  (p=0.011 n=28+28)
Reflect        84.2MB ± 0%      84.1MB ± 0%  -0.17%  (p=0.000 n=29+30)
Tar            27.7MB ± 0%      27.7MB ± 0%  -0.05%  (p=0.032 n=27+28)
XML            44.7MB ± 0%      44.7MB ± 0%    ~     (p=0.131 n=28+30)

name       old allocs/op    new allocs/op    delta
Template         373k ± 1%        370k ± 1%  -0.76%  (p=0.000 n=30+30)
Unicode          325k ± 1%        325k ± 1%    ~     (p=0.383 n=29+30)
GoTypes         1.16M ± 0%       1.15M ± 0%  -0.75%  (p=0.000 n=29+30)
Compiler        4.15M ± 0%       4.13M ± 0%  -0.59%  (p=0.000 n=30+29)
Flate            238k ± 1%        237k ± 1%  -0.62%  (p=0.000 n=30+30)
GoParser         304k ± 1%        302k ± 1%  -0.64%  (p=0.000 n=30+28)
Reflect         1.00M ± 0%       0.99M ± 0%  -1.10%  (p=0.000 n=29+30)
Tar              245k ± 1%        244k ± 1%  -0.59%  (p=0.000 n=27+29)
XML              391k ± 1%        389k ± 1%  -0.59%  (p=0.000 n=29+30)

Change-Id: Id7f456d690567c2b0a96b0d6d64de8784b6e305f
Reviewed-on: https://go-review.googlesource.com/36476
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-02-28 19:23:33 +00:00
Martin Möhrmann
a8f07310e3 cmd/compile: fix assignment order in string range loop
Fixes #18376.

Change-Id: I4fe24f479311cd4cd1bdad9a966b681e50e3d500
Reviewed-on: https://go-review.googlesource.com/35955
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-28 08:23:52 +00:00
Josh Bleecher Snyder
1e29cd8c2b cmd/compile: ignore some dead code during escape analysis
This is the escape analysis analog of CL 37499.

Fixes #12397
Fixes #16871

The only "moved to heap" decisions eliminated by this
CL in std+cmd are:

cmd/compile/internal/gc/const.go:1514: moved to heap: ac
cmd/compile/internal/gc/const.go:1515: moved to heap: bd
cmd/compile/internal/gc/const.go:1516: moved to heap: bc
cmd/compile/internal/gc/const.go:1517: moved to heap: ad
cmd/compile/internal/gc/const.go:1546: moved to heap: ac
cmd/compile/internal/gc/const.go:1547: moved to heap: bd
cmd/compile/internal/gc/const.go:1548: moved to heap: bc
cmd/compile/internal/gc/const.go:1549: moved to heap: ad
cmd/compile/internal/gc/const.go:1550: moved to heap: cc_plus
cmd/compile/internal/gc/export.go:162: moved to heap: copy
cmd/compile/internal/gc/mpfloat.go:66: moved to heap: b
cmd/compile/internal/gc/mpfloat.go:97: moved to heap: b

Change-Id: I0d420b69c84a41ba9968c394e8957910bab5edea
Reviewed-on: https://go-review.googlesource.com/37508
Reviewed-by: David Chase <drchase@google.com>
2017-02-27 21:31:04 +00:00
David Chase
febafe60d4 cmd/compile: added cheapexpr call to simplify operand of CONVIFACE
New special case for booleans and byte-sized integer types
converted to interfaces needs to ensure that the operand is
not too complex, if it were to appear in a parameter list
for example.

Added test, also increased the recursive node dump depth to
a level that was actually useful for an actual bug.

Fixes #19275.

Change-Id: If36ac3115edf439e886703f32d149ee0a46eb2a5
Reviewed-on: https://go-review.googlesource.com/37470
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-02-25 04:53:23 +00:00
Russ Cox
349b7820eb test: deflake locklinear a little
This should help on the openbsd systems where the test mostly passes.

I don't expect it to help on s390x where the test reliably fails.
But it should give more information when it does fail.

For #19276.

Change-Id: I496c291f2b4b0c747b8dd4315477d87d03010059
Reviewed-on: https://go-review.googlesource.com/37348
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-02-24 21:18:21 +00:00
Russ Cox
0b8c983ece runtime/pprof/internal/profile: move internal/pprof/profile here
Nothing needs internal/pprof anymore except the runtime/pprof tests.
Move the package here to prevent new dependencies.

Change-Id: Ia119af91cc2b980e0fa03a15f46f69d7f71d2926
Reviewed-on: https://go-review.googlesource.com/37165
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
2017-02-24 20:45:21 +00:00
Josh Bleecher Snyder
d9270ecb3a cmd/compile: evaluate zero-sized values converted to interfaces
CL 35562 substituted zerobase for the pointer for
interfaces containing zero-sized values.
However, it failed to evaluate the zero-sized value
expression for side-effects. Fix that.

The other similar interface value optimizations
are not affected, because they all actually use the
value one way or another.

Fixes #19246

Change-Id: I1168a99561477c63c29751d5cd04cf81b5ea509d
Reviewed-on: https://go-review.googlesource.com/37395
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-02-24 19:09:41 +00:00
Robert Griesemer
f8ae30c4a2 cmd/compile/internal/parser: improved a couple of error messages
The new syntax tree introduced with 1.8 represents send statements
(ch <- x) as statements; the old syntax tree represented them as
expressions (and parsed them as such) but complained if they were
used in expression context. As a consequence, some of the errors
that in the past were of the form "ch <- x used as value" now look
like "unexpected <- ..." because a "<-" is not valid according to
Go syntax in those situations. Accept the new error message.

Also: Fine-tune handling of misformed for loop headers.

Also: Minor cleanups/better comments.

Fixes #17590.

Change-Id: Ia541dea1f2f015c1b21f5b3ae44aacdec60a8aba
Reviewed-on: https://go-review.googlesource.com/37386
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-02-24 18:54:36 +00:00
David Chase
abdb2c35b6 cmd/compile: repaired loop-finder to handle trickier nesting
The loop-A-encloses-loop-C code did not properly handle the
case where really C was already known to be enclosed by B,
and A was nearest-outer to B, not C.

Fixes #19217.

Change-Id: I755dd768e823cb707abdc5302fed39c11cdb34d4
Reviewed-on: https://go-review.googlesource.com/37340
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-02-23 22:28:44 +00:00
David R. Jenni
d55f528826 cmd/compile: silence superfluous assignment error message
Avoid printing a second error message when a field of an undefined
variable is accessed.

Fixes #8440.

Change-Id: I3fe0b11fa3423cec3871cb01b5951efa8ea7451a
Reviewed-on: https://go-review.googlesource.com/36751
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-23 21:06:11 +00:00
Emmanuel Odeke
19d2061d50 cmd/compile: suppress callsite signatures if any type is unknown
Fixes #19012.

Fallback to return signatures without detailed types.
These error message will be of the form of issue:
* https://golang.org/issues/4215
* https://golang.org/issues/6750

So:
func f(x int, y uint) {
    return x > y
}

f(10, "a" < 3)

will give errors:
too many errors to return
too many arguments in call to f

instead of:

too many errors to return
  have (<T>)
  want ()
too many arguments in call to f
  have (number, <T>)
  want (number, number)

Change-Id: I680abc7cdd8444400e234caddf3ff49c2d69f53d
Reviewed-on: https://go-review.googlesource.com/36806
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-02-22 17:55:45 +00:00
David Chase
11b283092a cmd/compile: add opcode flag hasSideEffects for do-not-remove
Added a flag to generic and various architectures' atomic
operations that are judged to have observable side effects
and thus cannot be dead-code-eliminated.

Test requires GOMAXPROCS > 1 without preemption in loop.

Fixes #19182.

Change-Id: Id2230031abd2cca0bbb32fd68fc8a58fb912070f
Reviewed-on: https://go-review.googlesource.com/37333
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-02-22 15:15:47 +00:00
Cherry Zhang
6464e5dc4b cmd/compile: do not fold offset into load/store for args on ARM64
Args may be not at 8-byte aligned offset to SP. When the stack
frame is large, folding the offset of args may cause large
unaligned offsets that does not fit in a machine instruction on
ARM64. Therefore disable folding offsets for args.

This has small performance impact (see below). A better fix would
be letting the assembler backend fix up the offset by loading it
into a register if it doesn't fit into an instruction. And the
compiler can simply generate large load/stores with offset. Since
in most of the cases the offset is aligned or the stack frame is
small, it can fit in an instruction and no fixup is needed. But
this is too complicated for Go 1.8.

name                     old time/op    new time/op    delta
BinaryTree17-8              8.30s ± 0%     8.31s ± 0%    ~     (p=0.579 n=10+10)
Fannkuch11-8                6.14s ± 0%     6.18s ± 0%  +0.53%  (p=0.000 n=9+10)
FmtFprintfEmpty-8           117ns ± 0%     117ns ± 0%    ~     (all equal)
FmtFprintfString-8          196ns ± 0%     197ns ± 0%  +0.72%  (p=0.000 n=10+10)
FmtFprintfInt-8             204ns ± 0%     205ns ± 0%  +0.49%  (p=0.000 n=9+10)
FmtFprintfIntInt-8          302ns ± 0%     307ns ± 1%  +1.46%  (p=0.000 n=10+10)
FmtFprintfPrefixedInt-8     329ns ± 2%     326ns ± 0%    ~     (p=0.083 n=10+10)
FmtFprintfFloat-8           540ns ± 0%     542ns ± 0%  +0.46%  (p=0.000 n=8+7)
FmtManyArgs-8              1.20µs ± 1%    1.19µs ± 1%  -1.02%  (p=0.000 n=10+10)
GobDecode-8                17.3ms ± 1%    17.8ms ± 0%  +2.75%  (p=0.000 n=10+7)
GobEncode-8                15.3ms ± 1%    15.4ms ± 0%  +0.57%  (p=0.004 n=9+10)
Gzip-8                      789ms ± 0%     803ms ± 0%  +1.78%  (p=0.000 n=9+10)
Gunzip-8                    128ms ± 0%     130ms ± 0%  +1.73%  (p=0.000 n=10+9)
HTTPClientServer-8          202µs ± 6%     201µs ±10%    ~     (p=0.739 n=10+10)
JSONEncode-8               42.0ms ± 0%    42.1ms ± 0%  +0.19%  (p=0.028 n=10+9)
JSONDecode-8                159ms ± 0%     161ms ± 0%  +1.05%  (p=0.000 n=9+10)
Mandelbrot200-8            10.1ms ± 0%    10.1ms ± 0%  -0.07%  (p=0.000 n=10+9)
GoParse-8                  8.46ms ± 1%    8.61ms ± 1%  +1.77%  (p=0.000 n=10+10)
RegexpMatchEasy0_32-8       227ns ± 1%     226ns ± 0%  -0.35%  (p=0.001 n=10+9)
RegexpMatchEasy0_1K-8      1.63µs ± 0%    1.63µs ± 0%  -0.13%  (p=0.000 n=10+9)
RegexpMatchEasy1_32-8       250ns ± 0%     249ns ± 0%  -0.40%  (p=0.001 n=8+9)
RegexpMatchEasy1_1K-8      2.07µs ± 0%    2.08µs ± 0%  +0.05%  (p=0.027 n=9+9)
RegexpMatchMedium_32-8      350ns ± 0%     350ns ± 0%    ~     (p=0.412 n=9+8)
RegexpMatchMedium_1K-8      104µs ± 0%     104µs ± 0%  +0.31%  (p=0.000 n=10+7)
RegexpMatchHard_32-8       5.82µs ± 0%    5.82µs ± 0%    ~     (p=0.937 n=9+9)
RegexpMatchHard_1K-8        176µs ± 0%     176µs ± 0%  +0.03%  (p=0.000 n=9+8)
Revcomp-8                   1.36s ± 1%     1.37s ± 1%    ~     (p=0.218 n=10+10)
Template-8                  151ms ± 1%     156ms ± 1%  +3.21%  (p=0.000 n=10+10)
TimeParse-8                 737ns ± 0%     758ns ± 2%  +2.74%  (p=0.000 n=10+10)
TimeFormat-8                801ns ± 2%     789ns ± 1%  -1.51%  (p=0.000 n=10+10)
[Geo mean]                  142µs          143µs       +0.50%

Fixes #19137.

Change-Id: Ib8a21ea98c0ffb2d282a586535b213cc163e1b67
Reviewed-on: https://go-review.googlesource.com/37251
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-02-21 19:39:08 +00:00
Cherry Zhang
3557d54609 cmd/compile: check both syms when folding address into load/store on ARM64
The rules for folding addresses into load/stores checks sym1 is
not on stack (because the stack offset is not known at that point).
But sym1 could be nil, which invalidates the check. Check merged
sym instead.

Fixes #19137.

Change-Id: I8574da22ced1216bb5850403d8f08ec60a8d1005
Reviewed-on: https://go-review.googlesource.com/37145
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-02-17 21:23:24 +00:00
Cherry Zhang
98061fa5f3 cmd/compile: re-enable nilcheck removal in same block
Nil check removal in the same block is disabled due to issue 18725:
because the values are not ordered, a nilcheck may influence a
value that is logically before it. This CL re-enables same-block
nilcheck removal by ordering values in store order first.

Updates #18725.

Change-Id: I287a38525230c14c5412cbcdbc422547dabd54f6
Reviewed-on: https://go-review.googlesource.com/35496
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-02-17 19:19:59 +00:00
Robert Griesemer
1693e7b6f2 cmd/compile/internal/syntax: better errors and recovery for invalid character literals
Fixes #15611.

Change-Id: I352b145026466cafef8cf87addafbd30716bda24
Reviewed-on: https://go-review.googlesource.com/37138
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-02-16 21:46:43 +00:00
Russ Cox
990124da2a runtime: use balanced tree for addr lookup in semaphore implementation
CL 36792 fixed #17953, a linear scan caused by n goroutines piling into
two different locks that hashed to the same bucket in the semaphore table.
In that CL, n goroutines contending for 2 unfortunately chosen locks
went from O(n²) to O(n).

This CL fixes a different linear scan, when n goroutines are contending for
n/2 different locks that all hash to the same bucket in the semaphore table.
In this CL, n goroutines contending for n/2 unfortunately chosen locks
goes from O(n²) to O(n log n). This case is much less likely, but any linear
scan eventually hurts, so we might as well fix it while the problem is fresh
in our minds.

The new test in this CL checks for both linear scans.

The effect of this CL on the sync benchmarks is negligible
(but it fixes the new test).

name                      old time/op    new time/op    delta
Cond1-48                     576ns ±10%     575ns ±13%     ~     (p=0.679 n=71+71)
Cond2-48                    1.59µs ± 8%    1.61µs ± 9%     ~     (p=0.107 n=73+69)
Cond4-48                    4.56µs ± 7%    4.55µs ± 7%     ~     (p=0.670 n=74+72)
Cond8-48                    9.87µs ± 9%    9.90µs ± 7%     ~     (p=0.507 n=69+73)
Cond16-48                   20.4µs ± 7%    20.4µs ±10%     ~     (p=0.588 n=69+71)
Cond32-48                   45.4µs ±10%    45.4µs ±14%     ~     (p=0.944 n=73+73)
UncontendedSemaphore-48     19.7ns ±12%    19.7ns ± 8%     ~     (p=0.589 n=65+63)
ContendedSemaphore-48       55.4ns ±26%    54.9ns ±32%     ~     (p=0.441 n=75+75)
MutexUncontended-48         0.63ns ± 0%    0.63ns ± 0%     ~     (all equal)
Mutex-48                     210ns ± 6%     213ns ±10%   +1.30%  (p=0.035 n=70+74)
MutexSlack-48                210ns ± 7%     211ns ± 9%     ~     (p=0.184 n=71+72)
MutexWork-48                 299ns ± 5%     300ns ± 5%     ~     (p=0.678 n=73+75)
MutexWorkSlack-48            302ns ± 6%     300ns ± 5%     ~     (p=0.149 n=74+72)
MutexNoSpin-48               135ns ± 6%     135ns ±10%     ~     (p=0.788 n=67+75)
MutexSpin-48                 693ns ± 5%     689ns ± 6%     ~     (p=0.092 n=65+74)
Once-48                     0.22ns ±25%    0.22ns ±24%     ~     (p=0.882 n=74+73)
Pool-48                     5.88ns ±36%    5.79ns ±24%     ~     (p=0.655 n=69+69)
PoolOverflow-48             4.79µs ±18%    4.87µs ±20%     ~     (p=0.233 n=75+75)
SemaUncontended-48          0.80ns ± 1%    0.82ns ± 8%   +2.46%  (p=0.000 n=60+74)
SemaSyntNonblock-48          103ns ± 4%     102ns ± 5%   -1.11%  (p=0.003 n=75+75)
SemaSyntBlock-48             104ns ± 4%     104ns ± 5%     ~     (p=0.231 n=71+75)
SemaWorkNonblock-48          128ns ± 4%     129ns ± 6%   +1.51%  (p=0.000 n=63+75)
SemaWorkBlock-48             129ns ± 8%     130ns ± 7%     ~     (p=0.072 n=75+74)
RWMutexUncontended-48       2.35ns ± 1%    2.35ns ± 0%     ~     (p=0.144 n=70+55)
RWMutexWrite100-48           139ns ±18%     141ns ±21%     ~     (p=0.071 n=75+73)
RWMutexWrite10-48            145ns ± 9%     145ns ± 8%     ~     (p=0.553 n=75+75)
RWMutexWorkWrite100-48       297ns ±13%     297ns ±15%     ~     (p=0.519 n=75+74)
RWMutexWorkWrite10-48        588ns ± 7%     585ns ± 5%     ~     (p=0.173 n=73+70)
WaitGroupUncontended-48     0.87ns ± 0%    0.87ns ± 0%     ~     (all equal)
WaitGroupAddDone-48         63.2ns ± 4%    62.7ns ± 4%   -0.82%  (p=0.027 n=72+75)
WaitGroupAddDoneWork-48      109ns ± 5%     109ns ± 4%     ~     (p=0.233 n=75+75)
WaitGroupWait-48            0.17ns ± 0%    0.16ns ±16%   -8.55%  (p=0.000 n=56+75)
WaitGroupWaitWork-48        1.78ns ± 1%    2.08ns ± 5%  +16.92%  (p=0.000 n=74+70)
WaitGroupActuallyWait-48    52.0ns ± 3%    50.6ns ± 5%   -2.70%  (p=0.000 n=71+69)

https://perf.golang.org/search?q=upload:20170215.1

Change-Id: Ia29a8bd006c089e401ec4297c3038cca656bcd0a
Reviewed-on: https://go-review.googlesource.com/37103
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-16 17:52:15 +00:00
Robert Griesemer
d390283ff4 cmd/compile/internal/syntax: compiler directives must start at beginning of line
- ignore them, if they don't.
- added tests

Fixes #18393.

Change-Id: I13f87b81ac6b9138ab5031bb3dd6bebc4c548156
Reviewed-on: https://go-review.googlesource.com/37020
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-02-15 06:49:21 +00:00
Robert Griesemer
2770c507a5 cmd/compile: fix position for "missing type in composite literal" error
Fixes #18231.

Change-Id: If1615da4db0e6f0516369a1dc37340d80c78f237
Reviewed-on: https://go-review.googlesource.com/37018
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-02-15 01:33:44 +00:00
Robert Griesemer
5267ac2732 cmd/compile/internal/syntax: establish principled position information
Until now, the parser set the position for each Node to the position of
the first token belonging to that node. For compatibility with the now
defunct gc parser, in many places that position information was modified
when the gcCompat flag was set (which it was, by default). Furthermore,
in some places, position information was not set at all.

This change removes the gcCompat flag and all associated code, and sets
position information for all nodes in a more principled way, as proposed
by mdempsky (see #16943 for details). Specifically, the position of a
node may not be at the very beginning of the respective production. For
instance for an Operation `a + b`, the position associated with the node
is the position of the `+`. Thus, for `a + b + c` we now get different
positions for the two additions.

This change does not pass toolstash -cmp because position information
recorded in export data and pcline tables is different. There are no
other functional changes.

Added test suite testing the position of all nodes.

Fixes #16943.

Change-Id: I3fc02bf096bc3b3d7d2fa655dfd4714a1a0eb90c
Reviewed-on: https://go-review.googlesource.com/37017
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-02-15 01:33:03 +00:00
Cherry Zhang
78200799a2 cmd/compile: undo special handling of zero-valued STRUCTLIT
CL 35261 introduces special handling of zero-valued STRUCTLIT for
efficient struct zeroing. But it didn't cover all use cases, for
example, CONVNOP STRUCTLIT is not handled.

On the other hand, CL 34566 handles zeroing earlier, so we don't
need the change in CL 35261 for efficient zeroing. Other uses of
zero-valued struct literals are very rare. So undo the change in
walk.go in CL 35261.

Add a test for efficient zeroing.

Fixes #19084.

Change-Id: I0807f7423fb44d47bf325b3c1ce9611a14953853
Reviewed-on: https://go-review.googlesource.com/36955
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2017-02-14 18:57:56 +00:00
Robert Griesemer
efb3cab960 cmd/compile/internal/syntax: generalize error about var decls in init clauses
Change-Id: I62f9748b97bec245338ebf9686fbf6ad6dc6a9c2
Reviewed-on: https://go-review.googlesource.com/36931
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-02-13 23:15:32 +00:00
Robert Griesemer
f823d30514 cmd/compile/internal/syntax: better error for malformed 'if' statements
Use distinction between explicit and automatically inserted semicolons
to provide a better error message if the condition in an 'if' statement
is missing.

For #18747.

Change-Id: Iac167ae4e5ad53d2dc73f746b4dee9912434bb59
Reviewed-on: https://go-review.googlesource.com/36930
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-02-13 22:02:36 +00:00
Robert Griesemer
ee2f5fafd8 cmd/compile/internal/parser: don't crash after unexpected token
Added missing nil-check. We will get rid of the gcCompat corrections
shortly but it's still worthwhile having the new test case added.

Fixes #19056.

Change-Id: I35bd938a4d789058da15724e34c05e5e631ecad0
Reviewed-on: https://go-review.googlesource.com/36908
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-02-13 18:03:43 +00:00
Josh Bleecher Snyder
2c91bb4c8a cmd/compile: make panicwrap argument-free
When code defines a method on T,
the compiler generates a corresponding wrapper method on *T.
The first thing the wrapper does is check whether
the pointer is nil and if so, call panicwrap.
This is done to provide a useful error message.

The existing implementation gets its information
from arguments set up by the compiler.
However, with some trouble, this information can
be extracted from the name of the wrapper method itself.

Removing the arguments to panicwrap simplifies and
shrinks the wrapper method.
It also means that the call to panicwrap does not
require any stack space.
This enables a further optimization on amd64/x86,
which is to skip the function prologue if nothing
else in the method requires stack space.
This is frequently the case in simple, hot methods,
such as Less and Swap in sort.Interface implementations.

Fixes #19040.

Benchmarks for package sort on amd64:

name                  old time/op  new time/op  delta
SearchWrappers-8       104ns ± 1%   104ns ± 1%    ~     (p=0.286 n=27+27)
SortString1K-8         128µs ± 1%   128µs ± 1%  -0.44%  (p=0.004 n=30+30)
SortString1K_Slice-8   118µs ± 2%   117µs ± 1%    ~     (p=0.106 n=30+30)
StableString1K-8      18.6µs ± 1%  18.6µs ± 1%    ~     (p=0.446 n=28+26)
SortInt1K-8           65.9µs ± 1%  60.7µs ± 1%  -7.96%  (p=0.000 n=28+30)
StableInt1K-8         75.3µs ± 2%  72.8µs ± 1%  -3.41%  (p=0.000 n=30+30)
StableInt1K_Slice-8   57.7µs ± 1%  57.7µs ± 1%    ~     (p=0.515 n=30+30)
SortInt64K-8          6.28ms ± 1%  6.01ms ± 1%  -4.19%  (p=0.000 n=28+28)
SortInt64K_Slice-8    5.04ms ± 1%  5.04ms ± 1%    ~     (p=0.927 n=28+27)
StableInt64K-8        6.65ms ± 1%  6.38ms ± 1%  -3.97%  (p=0.000 n=26+30)
Sort1e2-8             37.9µs ± 1%  37.2µs ± 1%  -1.89%  (p=0.000 n=29+27)
Stable1e2-8           77.0µs ± 1%  74.7µs ± 1%  -3.06%  (p=0.000 n=27+30)
Sort1e4-8             8.21ms ± 2%  7.98ms ± 1%  -2.77%  (p=0.000 n=29+30)
Stable1e4-8           24.8ms ± 1%  24.3ms ± 1%  -2.31%  (p=0.000 n=28+30)
Sort1e6-8              1.27s ± 4%   1.22s ± 1%  -3.42%  (p=0.000 n=30+29)
Stable1e6-8            5.06s ± 1%   4.92s ± 1%  -2.77%  (p=0.000 n=25+29)
[Geo mean]             731µs        714µs       -2.29%

Before/after assembly for sort.(*intPairs).Less follows.
It can be optimized further, but that's for a follow-up CL.

Before:

"".(*intPairs).Less t=1 size=214 args=0x20 locals=0x38
	0x0000 00000 (<autogenerated>:1)	TEXT	"".(*intPairs).Less(SB), $56-32
	0x0000 00000 (<autogenerated>:1)	MOVQ	(TLS), CX
	0x0009 00009 (<autogenerated>:1)	CMPQ	SP, 16(CX)
	0x000d 00013 (<autogenerated>:1)	JLS	204
	0x0013 00019 (<autogenerated>:1)	SUBQ	$56, SP
	0x0017 00023 (<autogenerated>:1)	MOVQ	BP, 48(SP)
	0x001c 00028 (<autogenerated>:1)	LEAQ	48(SP), BP
	0x0021 00033 (<autogenerated>:1)	MOVQ	32(CX), BX
	0x0025 00037 (<autogenerated>:1)	TESTQ	BX, BX
	0x0028 00040 (<autogenerated>:1)	JEQ	55
	0x002a 00042 (<autogenerated>:1)	LEAQ	64(SP), DI
	0x002f 00047 (<autogenerated>:1)	CMPQ	(BX), DI
	0x0032 00050 (<autogenerated>:1)	JNE	55
	0x0034 00052 (<autogenerated>:1)	MOVQ	SP, (BX)
	0x0037 00055 (<autogenerated>:1)	NOP
	0x0037 00055 (<autogenerated>:1)	FUNCDATA	$0, gclocals·4032f753396f2012ad1784f398b170f4(SB)
	0x0037 00055 (<autogenerated>:1)	FUNCDATA	$1, gclocals·69c1753bd5f81501d95132d08af04464(SB)
	0x0037 00055 (<autogenerated>:1)	MOVQ	""..this+64(FP), AX
	0x003c 00060 (<autogenerated>:1)	TESTQ	AX, AX
	0x003f 00063 (<autogenerated>:1)	JEQ	$0, 135
	0x0041 00065 (<autogenerated>:1)	MOVQ	(AX), CX
	0x0044 00068 (<autogenerated>:1)	MOVQ	8(AX), AX
	0x0048 00072 (<autogenerated>:1)	MOVQ	"".i+72(FP), DX
	0x004d 00077 (<autogenerated>:1)	CMPQ	DX, AX
	0x0050 00080 (<autogenerated>:1)	JCC	$0, 128
	0x0052 00082 (<autogenerated>:1)	SHLQ	$4, DX
	0x0056 00086 (<autogenerated>:1)	MOVQ	(CX)(DX*1), DX
	0x005a 00090 (<autogenerated>:1)	MOVQ	"".j+80(FP), BX
	0x005f 00095 (<autogenerated>:1)	CMPQ	BX, AX
	0x0062 00098 (<autogenerated>:1)	JCC	$0, 128
	0x0064 00100 (<autogenerated>:1)	SHLQ	$4, BX
	0x0068 00104 (<autogenerated>:1)	MOVQ	(CX)(BX*1), AX
	0x006c 00108 (<autogenerated>:1)	CMPQ	DX, AX
	0x006f 00111 (<autogenerated>:1)	SETLT	AL
	0x0072 00114 (<autogenerated>:1)	MOVB	AL, "".~r2+88(FP)
	0x0076 00118 (<autogenerated>:1)	MOVQ	48(SP), BP
	0x007b 00123 (<autogenerated>:1)	ADDQ	$56, SP
	0x007f 00127 (<autogenerated>:1)	RET
	0x0080 00128 (<autogenerated>:1)	PCDATA	$0, $1
	0x0080 00128 (<autogenerated>:1)	CALL	runtime.panicindex(SB)
	0x0085 00133 (<autogenerated>:1)	UNDEF
	0x0087 00135 (<autogenerated>:1)	LEAQ	go.string."sort_test"(SB), AX
	0x008e 00142 (<autogenerated>:1)	MOVQ	AX, (SP)
	0x0092 00146 (<autogenerated>:1)	MOVQ	$9, 8(SP)
	0x009b 00155 (<autogenerated>:1)	LEAQ	go.string."intPairs"(SB), AX
	0x00a2 00162 (<autogenerated>:1)	MOVQ	AX, 16(SP)
	0x00a7 00167 (<autogenerated>:1)	MOVQ	$8, 24(SP)
	0x00b0 00176 (<autogenerated>:1)	LEAQ	go.string."Less"(SB), AX
	0x00b7 00183 (<autogenerated>:1)	MOVQ	AX, 32(SP)
	0x00bc 00188 (<autogenerated>:1)	MOVQ	$4, 40(SP)
	0x00c5 00197 (<autogenerated>:1)	PCDATA	$0, $1
	0x00c5 00197 (<autogenerated>:1)	CALL	runtime.panicwrap(SB)
	0x00ca 00202 (<autogenerated>:1)	UNDEF
	0x00cc 00204 (<autogenerated>:1)	NOP
	0x00cc 00204 (<autogenerated>:1)	PCDATA	$0, $-1
	0x00cc 00204 (<autogenerated>:1)	CALL	runtime.morestack_noctxt(SB)
	0x00d1 00209 (<autogenerated>:1)	JMP	0

After:

"".(*intPairs).Swap t=1 size=147 args=0x18 locals=0x8
	0x0000 00000 (<autogenerated>:1)	TEXT	"".(*intPairs).Swap(SB), $8-24
	0x0000 00000 (<autogenerated>:1)	MOVQ	(TLS), CX
	0x0009 00009 (<autogenerated>:1)	SUBQ	$8, SP
	0x000d 00013 (<autogenerated>:1)	MOVQ	BP, (SP)
	0x0011 00017 (<autogenerated>:1)	LEAQ	(SP), BP
	0x0015 00021 (<autogenerated>:1)	MOVQ	32(CX), BX
	0x0019 00025 (<autogenerated>:1)	TESTQ	BX, BX
	0x001c 00028 (<autogenerated>:1)	JEQ	43
	0x001e 00030 (<autogenerated>:1)	LEAQ	16(SP), DI
	0x0023 00035 (<autogenerated>:1)	CMPQ	(BX), DI
	0x0026 00038 (<autogenerated>:1)	JNE	43
	0x0028 00040 (<autogenerated>:1)	MOVQ	SP, (BX)
	0x002b 00043 (<autogenerated>:1)	NOP
	0x002b 00043 (<autogenerated>:1)	FUNCDATA	$0, gclocals·e6397a44f8e1b6e77d0f200b4fba5269(SB)
	0x002b 00043 (<autogenerated>:1)	FUNCDATA	$1, gclocals·69c1753bd5f81501d95132d08af04464(SB)
	0x002b 00043 (<autogenerated>:1)	MOVQ	""..this+16(FP), AX
	0x0030 00048 (<autogenerated>:1)	TESTQ	AX, AX
	0x0033 00051 (<autogenerated>:1)	JEQ	$0, 140
	0x0035 00053 (<autogenerated>:1)	MOVQ	(AX), CX
	0x0038 00056 (<autogenerated>:1)	MOVQ	8(AX), AX
	0x003c 00060 (<autogenerated>:1)	MOVQ	"".i+24(FP), DX
	0x0041 00065 (<autogenerated>:1)	CMPQ	DX, AX
	0x0044 00068 (<autogenerated>:1)	JCC	$0, 133
	0x0046 00070 (<autogenerated>:1)	SHLQ	$4, DX
	0x004a 00074 (<autogenerated>:1)	MOVQ	8(CX)(DX*1), BX
	0x004f 00079 (<autogenerated>:1)	MOVQ	(CX)(DX*1), SI
	0x0053 00083 (<autogenerated>:1)	MOVQ	"".j+32(FP), DI
	0x0058 00088 (<autogenerated>:1)	CMPQ	DI, AX
	0x005b 00091 (<autogenerated>:1)	JCC	$0, 133
	0x005d 00093 (<autogenerated>:1)	SHLQ	$4, DI
	0x0061 00097 (<autogenerated>:1)	MOVQ	8(CX)(DI*1), AX
	0x0066 00102 (<autogenerated>:1)	MOVQ	(CX)(DI*1), R8
	0x006a 00106 (<autogenerated>:1)	MOVQ	R8, (CX)(DX*1)
	0x006e 00110 (<autogenerated>:1)	MOVQ	AX, 8(CX)(DX*1)
	0x0073 00115 (<autogenerated>:1)	MOVQ	SI, (CX)(DI*1)
	0x0077 00119 (<autogenerated>:1)	MOVQ	BX, 8(CX)(DI*1)
	0x007c 00124 (<autogenerated>:1)	MOVQ	(SP), BP
	0x0080 00128 (<autogenerated>:1)	ADDQ	$8, SP
	0x0084 00132 (<autogenerated>:1)	RET
	0x0085 00133 (<autogenerated>:1)	PCDATA	$0, $1
	0x0085 00133 (<autogenerated>:1)	CALL	runtime.panicindex(SB)
	0x008a 00138 (<autogenerated>:1)	UNDEF
	0x008c 00140 (<autogenerated>:1)	PCDATA	$0, $1
	0x008c 00140 (<autogenerated>:1)	CALL	runtime.panicwrap(SB)
	0x0091 00145 (<autogenerated>:1)	UNDEF

Change-Id: I15bb8435f0690badb868799f313ed8817335efd3
Reviewed-on: https://go-review.googlesource.com/36809
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-02-11 23:27:35 +00:00
Dhananjay Nakrani
1cde87b312 cmd/compile: Ensure left-to-right assignment
Add temporaries to reorder the assignment for OAS2XXX nodes.
This makes orderstmt(), rewrite
  a, b, c = ...
as
  tmp1, tmp2, tmp3 = ...
  a, b, c = tmp1, tmp2, tmp3
and
  a, ok = ...
as
  t1, t2 = ...
  a  = t1
  ok = t2

Fixes #13433.

Change-Id: Id0f5956e3a254d0a6f4b89b5f7b0e055b1f0e21f
Reviewed-on: https://go-review.googlesource.com/34713
Run-TryBot: Dhananjay Nakrani <dhananjayn@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-02-11 21:46:21 +00:00
Robert Griesemer
3fd3171c2c cmd/compile/internal/syntax: removed gcCompat code needed to pass orig. tests
The gcCompat mode was introduced to match the new parser's node position
setup exactly with the positions used by the original parser. Some of the
gcCompat adjustments were required to satisfy syntax error test cases,
and the rest were required to make toolstash cmp pass.

This change removes the former gcCompat adjustments and instead adjusts
the respective test cases as necessary. In some cases this makes the error
lines consistent with the ones reported by gccgo.

Where it has changed, the position associated with a given syntactic construct
is the position (line/col number) of the left-most token belonging to the
construct.

Change-Id: I5b60c00c5999a895c4d6d6e9b383c6405ccf725c
Reviewed-on: https://go-review.googlesource.com/36695
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-02-10 01:22:30 +00:00
Robert Griesemer
3c22e5ca27 cmd/compile/internal/parser: improved syntax error for incorrect if/for/switch header
Starting the error message with "expecting" rather than "missing"
causes the syntax error mechanism to add additional helpful info
(it recognizes "expecting" but not "missing").

Fixes #17328.

Change-Id: I8482ca5e5a6a6b22e0ed0d831b7328e264156334
Reviewed-on: https://go-review.googlesource.com/36637
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-09 03:54:47 +00:00
Robert Griesemer
9799622f09 cmd/compile/internal/syntax: differentiate between ';' and '\n' in syntax errors
Towards better syntax error messages: With this change, the parser knows whether
a semicolon was an actual ';' in the source, or whether it was an automatically
inserted semicolon as result of a '\n' or EOF. Using this information in error
messages makes them more understandable.

For #17328.

Change-Id: I8cd9accee8681b62569d0ecef922d38682b401eb
Reviewed-on: https://go-review.googlesource.com/36636
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-02-09 01:45:17 +00:00
Cherry Zhang
a146dd3a2f cmd/compile: handle DOT STRUCTLIT for zero-valued struct in SSA
CL 35261 makes SSA handle zero-valued STRUCTLIT, but DOT operation
was not handled.

Fixes #18994.

Change-Id: Ic7976036acca1523b0b14afac4d170797e8aee20
Reviewed-on: https://go-review.googlesource.com/36565
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-08 21:01:51 +00:00
David Lazar
e3efdffacd cmd/compile: include linknames in export data
This lets the compiler inline functions that contain a linknamed symbol.
Previously, the net/http tests would fail to build with -l=4 because
the compiler inlined functions that call net.byteIndex (which is
linknamed to strings.IndexByte).

This changes only the compiler-specific export data, so we don't need to
bump the export format version number.

The following benchmark results show how the size of package export data
is impacted by this change. These benchmarks were created by compiling
the go1 benchmark and running `go tool pack x` to extract the export
data from the resulting .a files.

name                                          old bytes   new bytes   delta
bufio                                        3.48k ± 0%  3.58k ± 0%  +2.90%
bytes                                        5.05k ± 0%  5.16k ± 0%  +2.16%
compress/bzip2                               2.61k ± 0%  2.68k ± 0%  +2.68%
compress/flate                               5.07k ± 0%  5.14k ± 0%  +1.40%
compress/gzip                                8.26k ± 0%  8.40k ± 0%  +1.70%
container/list                               1.69k ± 0%  1.76k ± 0%  +4.07%
context                                      3.93k ± 0%  4.01k ± 0%  +1.86%
crypto                                       1.03k ± 0%  1.03k ± 0%  +0.39%
crypto/aes                                     475 ± 0%    475 ± 0%  +0.00%
crypto/cipher                                1.18k ± 0%  1.18k ± 0%  +0.00%
crypto/des                                     502 ± 0%    502 ± 0%  +0.00%
crypto/dsa                                   5.71k ± 0%  5.77k ± 0%  +1.16%
crypto/ecdsa                                 6.67k ± 0%  6.75k ± 0%  +1.08%
crypto/elliptic                              6.28k ± 0%  6.35k ± 0%  +1.07%
crypto/hmac                                    464 ± 0%    464 ± 0%  +0.00%
crypto/internal/cipherhw                       313 ± 0%    313 ± 0%  +0.00%
crypto/md5                                     691 ± 0%    695 ± 0%  +0.58%
crypto/rand                                  5.37k ± 0%  5.43k ± 0%  +1.23%
crypto/rc4                                     512 ± 0%    512 ± 0%  +0.00%
crypto/rsa                                   7.05k ± 0%  7.12k ± 0%  +1.05%
crypto/sha1                                    756 ± 0%    760 ± 0%  +0.53%
crypto/sha256                                  523 ± 0%    523 ± 0%  +0.00%
crypto/sha512                                  662 ± 0%    662 ± 0%  +0.00%
crypto/subtle                                  835 ± 0%    873 ± 0%  +4.55%
crypto/tls                                   28.1k ± 0%  28.5k ± 0%  +1.30%
crypto/x509                                  17.7k ± 0%  17.9k ± 0%  +1.04%
crypto/x509/pkix                             9.75k ± 0%  9.90k ± 0%  +1.50%
encoding                                       473 ± 0%    473 ± 0%  +0.00%
encoding/asn1                                1.41k ± 0%  1.42k ± 0%  +1.00%
encoding/base64                              1.67k ± 0%  1.69k ± 0%  +0.90%
encoding/binary                              2.65k ± 0%  2.76k ± 0%  +4.07%
encoding/gob                                 13.3k ± 0%  13.5k ± 0%  +1.65%
encoding/hex                                   854 ± 0%    857 ± 0%  +0.35%
encoding/json                                11.9k ± 0%  12.1k ± 0%  +1.71%
encoding/pem                                   484 ± 0%    484 ± 0%  +0.00%
errors                                         360 ± 0%    361 ± 0%  +0.28%
flag                                         7.32k ± 0%  7.42k ± 0%  +1.48%
fmt                                          1.42k ± 0%  1.42k ± 0%  +0.00%
go/ast                                       15.7k ± 0%  15.8k ± 0%  +1.07%
go/parser                                    7.48k ± 0%  7.59k ± 0%  +1.55%
go/scanner                                   3.88k ± 0%  3.94k ± 0%  +1.39%
go/token                                     3.51k ± 0%  3.53k ± 0%  +0.60%
hash                                           507 ± 0%    507 ± 0%  +0.00%
hash/crc32                                     685 ± 0%    685 ± 0%  +0.00%
internal/nettrace                              474 ± 0%    474 ± 0%  +0.00%
internal/pprof/profile                       8.29k ± 0%  8.36k ± 0%  +0.89%
internal/race                                  511 ± 0%    511 ± 0%  +0.00%
internal/singleflight                          966 ± 0%    969 ± 0%  +0.31%
internal/syscall/unix                          427 ± 0%    427 ± 0%  +0.00%
io                                           3.48k ± 0%  3.52k ± 0%  +1.15%
io/ioutil                                    5.30k ± 0%  5.38k ± 0%  +1.53%
log                                          4.46k ± 0%  4.53k ± 0%  +1.59%
math                                         3.72k ± 0%  3.75k ± 0%  +0.75%
math/big                                     8.91k ± 0%  9.01k ± 0%  +1.15%
math/rand                                    1.29k ± 0%  1.30k ± 0%  +0.46%
mime                                         2.59k ± 0%  2.63k ± 0%  +1.55%
mime/multipart                               3.61k ± 0%  3.68k ± 0%  +1.80%
mime/quotedprintable                         2.20k ± 0%  2.25k ± 0%  +2.50%
net                                          21.1k ± 0%  21.3k ± 0%  +1.10%
net/http                                     56.6k ± 0%  57.3k ± 0%  +1.28%
net/http/httptest                            33.6k ± 0%  34.1k ± 0%  +1.38%
net/http/httptrace                           14.4k ± 0%  14.5k ± 0%  +1.29%
net/http/internal                            2.70k ± 0%  2.77k ± 0%  +2.59%
net/textproto                                4.51k ± 0%  4.60k ± 0%  +1.82%
net/url                                      1.71k ± 0%  1.73k ± 0%  +1.41%
os                                           11.3k ± 0%  11.4k ± 0%  +1.36%
path                                           587 ± 0%    589 ± 0%  +0.34%
path/filepath                                4.46k ± 0%  4.55k ± 0%  +1.88%
reflect                                      6.39k ± 0%  6.43k ± 0%  +0.72%
regexp                                       5.82k ± 0%  5.88k ± 0%  +1.12%
regexp/syntax                                3.22k ± 0%  3.24k ± 0%  +0.62%
runtime                                      12.9k ± 0%  13.2k ± 0%  +1.94%
runtime/cgo                                    229 ± 0%    229 ± 0%  +0.00%
runtime/debug                                3.66k ± 0%  3.72k ± 0%  +1.86%
runtime/internal/atomic                        905 ± 0%    905 ± 0%  +0.00%
runtime/internal/sys                         2.00k ± 0%  2.05k ± 0%  +2.55%
runtime/pprof                                4.16k ± 0%  4.23k ± 0%  +1.66%
runtime/pprof/internal/protopprof            11.5k ± 0%  11.7k ± 0%  +1.27%
runtime/trace                                  354 ± 0%    354 ± 0%  +0.00%
sort                                         1.63k ± 0%  1.68k ± 0%  +2.94%
strconv                                      1.84k ± 0%  1.85k ± 0%  +0.54%
strings                                      3.87k ± 0%  3.97k ± 0%  +2.48%
sync                                         1.51k ± 0%  1.52k ± 0%  +0.33%
sync/atomic                                  1.58k ± 0%  1.60k ± 0%  +1.27%
syscall                                      53.2k ± 0%  53.3k ± 0%  +0.20%
testing                                      8.14k ± 0%  8.26k ± 0%  +1.49%
testing/internal/testdeps                      597 ± 0%    598 ± 0%  +0.17%
text/tabwriter                               3.09k ± 0%  3.14k ± 0%  +1.85%
text/template                                15.4k ± 0%  15.7k ± 0%  +1.89%
text/template/parse                          8.90k ± 0%  9.12k ± 0%  +2.46%
time                                         5.75k ± 0%  5.86k ± 0%  +1.86%
unicode                                      4.62k ± 0%  4.62k ± 0%  +0.07%
unicode/utf16                                  693 ± 0%    706 ± 0%  +1.88%
unicode/utf8                                 1.05k ± 0%  1.07k ± 0%  +1.14%
vendor/golang_org/x/crypto/chacha20poly1305  1.25k ± 0%  1.26k ± 0%  +0.64%
vendor/golang_org/x/crypto/curve25519          392 ± 0%    392 ± 0%  +0.00%
vendor/golang_org/x/crypto/poly1305            426 ± 0%    426 ± 0%  +0.00%
vendor/golang_org/x/net/http2/hpack          4.19k ± 0%  4.26k ± 0%  +1.69%
vendor/golang_org/x/net/idna                   355 ± 0%    355 ± 0%  +0.00%
vendor/golang_org/x/net/lex/httplex            609 ± 0%    615 ± 0%  +0.99%
vendor/golang_org/x/text/transform           1.31k ± 0%  1.31k ± 0%  +0.08%
vendor/golang_org/x/text/unicode/norm        5.78k ± 0%  5.90k ± 0%  +2.06%
vendor/golang_org/x/text/width               1.24k ± 0%  1.24k ± 0%  +0.16%
[Geo mean]                                    2.49k       2.52k       +1.10%

Fixes #18167.

Change-Id: Ia5b7e70adc9652c7ee9954ca2efc1c59fa79be2b
Reviewed-on: https://go-review.googlesource.com/33911
Run-TryBot: David Lazar <lazard@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-02-08 20:59:45 +00:00
Cherry Zhang
160914e33c cmd/compile: do not use "oaslit" for global
The compiler did not emit write barrier for assigning global with
struct literal, like global = T{} where T contains pointer.

The relevant code path is:
walkexpr OAS var_ OSTRUCTLIT
    oaslit
        anylit OSTRUCTLIT
            walkexpr OAS var_ nil
            return without adding write barrier
    return true
break (without adding write barrier)

This CL makes oaslit not apply to globals. See also CL
https://go-review.googlesource.com/c/36355/ for an alternative
fix.

The downside of this is that it generates static data for zeroing
struct now. Also this only covers global. If there is any lurking
bug with implicit zeroing other than globals, this doesn't fix.

Fixes #18956.

Change-Id: Ibcd27e4fae3aa38390ffa94a32a9dd7a802e4b37
Reviewed-on: https://go-review.googlesource.com/36410
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-07 17:23:23 +00:00
Shintaro Kaneko
936749efb0 test: improve output format of issue10607a.go test
Change-Id: Iad5ff820a95f5082b75aa5260e40c33c7b0ecf22
Reviewed-on: https://go-review.googlesource.com/35990
Reviewed-by: Russ Cox <rsc@golang.org>
2017-02-07 14:00:27 +00:00
Robert Griesemer
3b68a64769 cmd/compile/internal/syntax: make a parser error "1.7 compliant"
For code such as

	if a := 10 { ...

the 1.7 compiler reported

	a := 10 used as value

while the 1.8 compiler reported

	invalid condition, tag, or type switch guard

Changed the error message to match the 1.7 compiler.

Fixes #18915.

Change-Id: I01308862e461922e717f9f8295a9db53d5a914eb
Reviewed-on: https://go-review.googlesource.com/36470
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-06 23:33:07 +00:00
Keith Randall
807c80fce3 cmd/compile: using CONV instead of CONVNOP for interface conversions
We shouldn't use CONVNOP for conversions between two different
nonempty interface types, because we want to update the itab
in those situations.

Fixes #18595

After this CL, we are guaranteed that itabs are unique, that is
there is only one itab per compile-time-type/concrete type pair.
See also the tests in CL 35115 and 35116 which make sure this
invariant holds even for shared libraries and plugins.

Unique itabs are required for CL 34810 (faster type switch code).

R=go1.9

Change-Id: Id27d2e01ded706680965e4cb69d7c7a24ac2161b
Reviewed-on: https://go-review.googlesource.com/35119
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2017-02-06 20:00:05 +00:00
Cherry Zhang
b53f0f8c96 cmd/compile: do not fold large offset on ARM64
Fixes #18933.

Change-Id: I8bb98e95bb4486a086d93bcf99e3a37488e77b03
Reviewed-on: https://go-review.googlesource.com/36318
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-02-04 16:46:11 +00:00
Michael Munday
ddf807fce8 cmd/compile: fix type propagation through s390x SSA rules
This CL fixes two issues:

1. Load ops were initially always lowered to unsigned loads, even
   for signed types. This was fine by itself however LoadReg ops
   (used to re-load spilled values) were lowered to signed loads
   for signed types. This meant that spills could invalidate
   optimizations that assumed the original unsigned load.

2. Types were not always being maintained correctly through rules
   designed to eliminate unnecessary zero and sign extensions.

Fixes #18906.

Change-Id: I95785dcadba03f7e3e94524677e7d8d3d3b9b737
Reviewed-on: https://go-review.googlesource.com/36256
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-02-03 21:27:21 +00:00
Keith Randall
8179b9b462 cmd/compile: make sure output params are live if there is a defer
If there is a defer, and that defer recovers, then the caller
can see all of the output parameters.  That means that we must
mark all the output parameters live at any point which might panic.

If there is no defer then this is not necessary.  This is implemented.

We could also detect whether there is a recover in any of the defers.
If not, we would need to mark only output params that the defer
actually references (and the closure mechanism already does that).
This is not implemented.

Fixes #18860.

Change-Id: If984fe6686eddce9408bf25e725dd17fc16b8578
Reviewed-on: https://go-review.googlesource.com/36030
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
2017-02-03 15:21:47 +00:00
Cherry Zhang
fddc004537 cmd/compile: remove nil check for Zero/Move on 386, AMD64, S390X
Fixes #18003.

Change-Id: Iadcc5c424c64badecfb5fdbd4dbd9197df56182c
Reviewed-on: https://go-review.googlesource.com/33421
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-02-02 21:28:38 +00:00