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Author SHA1 Message Date
uropek f1973f3164 test: fix spelling of `caught be the compiler` to `caught by the compiler` 
Change-Id: Id21cdce35963dcdb96cc06252170590224c5aa17
GitHub-Last-Rev: 429dad0ceb
GitHub-Pull-Request: golang/go#28000
Reviewed-on: https://go-review.googlesource.com/c/139424
Reviewed-by: Ian Lance Taylor <iant@golang.org>
 2018-10-04 00:49:49 +00:00
Keith Randall c91ce3cc7b test: stress test for stack objects 
Allocate a long linked list on the stack. This tests both
lots of live stack objects, and lots of intra-stack pointers
to those objects.

Change-Id: I169e067416455737774851633b1e5367e10e1cf2
Reviewed-on: https://go-review.googlesource.com/c/135296
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-10-03 19:54:29 +00:00
Keith Randall 9dac0a8132 runtime: on a signal, set traceback address to a deferreturn call 
When a function triggers a signal (like a segfault which translates to
a nil pointer exception) during execution, a sigpanic handler is just
below it on the stack.  The function itself did not stop at a
safepoint, so we have to figure out what safepoint we should use to
scan its stack frame.

Previously we used the site of the most recent defer to get the live
variables at the signal site. That answer is not quite correct, as
explained in #27518. Instead, use the site of a deferreturn call.
It has all the right variables marked as live (no args, all the return
values, except those that escape to the heap, in which case the
corresponding PAUTOHEAP variables will be live instead).

This CL requires stack objects, so that all the local variables
and args referenced by the deferred closures keep the right variables alive.

Fixes #27518

Change-Id: Id45d8a8666759986c203181090b962e2981e48ca
Reviewed-on: https://go-review.googlesource.com/c/134637
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-10-03 19:54:23 +00:00
Keith Randall 9a8372f8bd cmd/compile,runtime: remove ambiguously live logic 
The previous CL introduced stack objects. This CL removes the old
ambiguously live liveness analysis. After this CL we're relying
on stack objects exclusively.

Update a bunch of liveness tests to reflect the new world.

Fixes #22350

Change-Id: I739b26e015882231011ce6bc1a7f426049e59f31
Reviewed-on: https://go-review.googlesource.com/c/134156
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-10-03 19:54:16 +00:00
Cherry Zhang c96e3bcc97 cmd/compile: fix type of OffPtr in some optimization rules 
In some optimization rules the type of generated OffPtr was
incorrectly set to the type of the pointee, instead of the
pointer. When the OffPtr value is spilled, this may generate
a spill of the wrong type, e.g. a floating point spill of an
integer (pointer) value. On Wasm, this leads to invalid
bytecode.

Fixes #27961.

Change-Id: I5d464847eb900ed90794105c0013a1a7330756cc
Reviewed-on: https://go-review.googlesource.com/c/139257
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Richard Musiol <neelance@gmail.com>
 2018-10-03 15:01:47 +00:00
Carlos Eduardo Seo 9aed4cc395 cmd/compile: instrinsify math/bits.Mul on ppc64x 
Add SSA rules to intrinsify Mul/Mul64 on ppc64x.

benchmark             old ns/op     new ns/op     delta
BenchmarkMul-40       8.80          0.93          -89.43%
BenchmarkMul32-40     1.39          1.39          +0.00%
BenchmarkMul64-40     5.39          0.93          -82.75%

Updates #24813

Change-Id: I6e95bfbe976a2278bd17799df184a7fbc0e57829
Reviewed-on: https://go-review.googlesource.com/138917
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
 2018-10-02 18:56:06 +00:00
Keith Randall ef50373983 reflect: ensure correct scanning of return values 
During a call to a reflect-generated function or method (via
makeFuncStub or methodValueCall), when should we scan the return
values?

When we're starting a reflect call, the space on the stack for the
return values is not initialized yet, as it contains whatever junk was
on the stack of the caller at the time. The return space must not be
scanned during a GC.

When we're finishing a reflect call, the return values are
initialized, and must be scanned during a GC to make sure that any
pointers in the return values are found and their referents retained.

When the GC stack walk comes across a reflect call in progress on the
stack, it needs to know whether to scan the results or not. It doesn't
know the progress of the reflect call, so it can't decide by
itself. The reflect package needs to tell it.

This CL adds another slot in the frame of makeFuncStub and
methodValueCall so we can put a boolean in there which tells the
runtime whether to scan the results or not.

This CL also adds the args length to reflectMethodValue so the
runtime can restrict its scanning to only the args section (not the
results) if the reflect package says the results aren't ready yet.

Do a delicate dance in the reflect package to set the "results are
valid" bit. We need to make sure we set the bit only after we've
copied the results back to the stack. But we must set the bit before
we drop reflect's copy of the results. Otherwise, we might have a
state where (temporarily) no one has a live copy of the results.
That's the state we were observing in issue #27695 before this CL.

The bitmap used by the runtime currently contains only the args.
(Actually, it contains all the bits, but the size is set so we use
only the args portion.) This is safe for early in a reflect call, but
unsafe late in a reflect call. The test issue27695.go demonstrates
this unsafety. We change the bitmap to always include both args
and results, and decide at runtime which portion to use.

issue27695.go only has a test for method calls. Function calls were ok
because there wasn't a safepoint between when reflect dropped its copy
of the return values and when the caller is resumed. This may change
when we introduce safepoints everywhere.

This truncate-to-only-the-args was part of CL 9888 (in 2015). That
part of the CL fixed the problem demonstrated in issue27695b.go but
introduced the problem demonstrated in issue27695.go.

TODO, in another CL: simplify FuncLayout and its test. stack return
value is now identical to frametype.ptrdata + frametype.gcdata.

Fixes #27695

Change-Id: I2d49b34e34a82c6328b34f02610587a291b25c5f
Reviewed-on: https://go-review.googlesource.com/137440
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
 2018-09-29 20:25:24 +00:00
Ben Shi 5aeecc4530 cmd/compile: optimize arm64's code with more shifted operations 
This CL optimizes arm64's NEG/MVN/TST/CMN with a shifted operand.

1. The total size of pkg/android_arm64 decreases about 0.2KB, excluding
cmd/compile/ .

2. The go1 benchmark shows no regression, excluding noise.
name                     old time/op    new time/op    delta
BinaryTree17-4              16.4s ± 1%     16.4s ± 1%    ~     (p=0.914 n=29+29)
Fannkuch11-4                8.72s ± 0%     8.72s ± 0%    ~     (p=0.274 n=30+29)
FmtFprintfEmpty-4           174ns ± 0%     174ns ± 0%    ~     (all equal)
FmtFprintfString-4          370ns ± 0%     370ns ± 0%    ~     (all equal)
FmtFprintfInt-4             419ns ± 0%     419ns ± 0%    ~     (all equal)
FmtFprintfIntInt-4          672ns ± 1%     675ns ± 2%    ~     (p=0.217 n=28+30)
FmtFprintfPrefixedInt-4     806ns ± 0%     806ns ± 0%    ~     (p=0.402 n=30+28)
FmtFprintfFloat-4          1.09µs ± 0%    1.09µs ± 0%  +0.02%  (p=0.011 n=22+27)
FmtManyArgs-4              2.67µs ± 0%    2.68µs ± 0%    ~     (p=0.279 n=29+30)
GobDecode-4                33.1ms ± 1%    33.1ms ± 0%    ~     (p=0.052 n=28+29)
GobEncode-4                29.6ms ± 0%    29.6ms ± 0%  +0.08%  (p=0.013 n=28+29)
Gzip-4                      1.38s ± 2%     1.39s ± 2%    ~     (p=0.071 n=29+29)
Gunzip-4                    139ms ± 0%     139ms ± 0%    ~     (p=0.265 n=29+29)
HTTPClientServer-4          789µs ± 4%     785µs ± 4%    ~     (p=0.206 n=29+28)
JSONEncode-4               49.7ms ± 0%    49.6ms ± 0%  -0.24%  (p=0.000 n=30+30)
JSONDecode-4                266ms ± 1%     267ms ± 1%  +0.34%  (p=0.000 n=30+30)
Mandelbrot200-4            16.6ms ± 0%    16.6ms ± 0%    ~     (p=0.835 n=28+30)
GoParse-4                  15.9ms ± 0%    15.8ms ± 0%  -0.29%  (p=0.000 n=27+30)
RegexpMatchEasy0_32-4       380ns ± 0%     381ns ± 0%  +0.18%  (p=0.000 n=30+30)
RegexpMatchEasy0_1K-4      1.18µs ± 0%    1.19µs ± 0%  +0.23%  (p=0.000 n=30+30)
RegexpMatchEasy1_32-4       357ns ± 0%     358ns ± 0%  +0.28%  (p=0.000 n=29+29)
RegexpMatchEasy1_1K-4      2.04µs ± 0%    2.04µs ± 0%  +0.06%  (p=0.006 n=30+30)
RegexpMatchMedium_32-4      589ns ± 0%     590ns ± 0%  +0.24%  (p=0.000 n=28+30)
RegexpMatchMedium_1K-4      162µs ± 0%     162µs ± 0%  -0.01%  (p=0.027 n=26+29)
RegexpMatchHard_32-4       9.58µs ± 0%    9.58µs ± 0%    ~     (p=0.935 n=30+30)
RegexpMatchHard_1K-4        287µs ± 0%     287µs ± 0%    ~     (p=0.387 n=29+30)
Revcomp-4                   2.50s ± 0%     2.50s ± 0%  -0.10%  (p=0.020 n=28+28)
Template-4                  310ms ± 0%     310ms ± 1%    ~     (p=0.406 n=30+30)
TimeParse-4                1.68µs ± 0%    1.68µs ± 0%  +0.03%  (p=0.014 n=30+17)
TimeFormat-4               1.65µs ± 0%    1.66µs ± 0%  +0.32%  (p=0.000 n=27+29)
[Geo mean]                  247µs          247µs       +0.05%

name                     old speed      new speed      delta
GobDecode-4              23.2MB/s ± 0%  23.2MB/s ± 0%  -0.08%  (p=0.032 n=27+29)
GobEncode-4              26.0MB/s ± 0%  25.9MB/s ± 0%  -0.10%  (p=0.011 n=29+29)
Gzip-4                   14.1MB/s ± 2%  14.0MB/s ± 2%    ~     (p=0.081 n=29+29)
Gunzip-4                  139MB/s ± 0%   139MB/s ± 0%    ~     (p=0.290 n=29+29)
JSONEncode-4             39.0MB/s ± 0%  39.1MB/s ± 0%  +0.25%  (p=0.000 n=29+30)
JSONDecode-4             7.30MB/s ± 1%  7.28MB/s ± 1%  -0.33%  (p=0.000 n=30+30)
GoParse-4                3.65MB/s ± 0%  3.66MB/s ± 0%  +0.29%  (p=0.000 n=27+30)
RegexpMatchEasy0_32-4    84.1MB/s ± 0%  84.0MB/s ± 0%  -0.17%  (p=0.000 n=30+28)
RegexpMatchEasy0_1K-4     864MB/s ± 0%   862MB/s ± 0%  -0.24%  (p=0.000 n=30+30)
RegexpMatchEasy1_32-4    89.5MB/s ± 0%  89.3MB/s ± 0%  -0.18%  (p=0.000 n=28+24)
RegexpMatchEasy1_1K-4     502MB/s ± 0%   502MB/s ± 0%  -0.05%  (p=0.008 n=30+29)
RegexpMatchMedium_32-4   1.70MB/s ± 0%  1.69MB/s ± 0%  -0.59%  (p=0.000 n=29+30)
RegexpMatchMedium_1K-4   6.31MB/s ± 0%  6.31MB/s ± 0%  +0.05%  (p=0.005 n=30+26)
RegexpMatchHard_32-4     3.34MB/s ± 0%  3.34MB/s ± 0%    ~     (all equal)
RegexpMatchHard_1K-4     3.57MB/s ± 0%  3.57MB/s ± 0%    ~     (all equal)
Revcomp-4                 102MB/s ± 0%   102MB/s ± 0%  +0.10%  (p=0.022 n=28+28)
Template-4               6.26MB/s ± 0%  6.26MB/s ± 1%    ~     (p=0.768 n=30+30)
[Geo mean]               24.2MB/s       24.1MB/s       -0.08%

Change-Id: I494f9db7f8a568a00e9c74ae25086a58b2221683
Reviewed-on: https://go-review.googlesource.com/137976
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-28 15:05:17 +00:00
Ben Shi d60cf39f8e cmd/compile: optimize arm64's MADD and MSUB 
This CL implements constant folding for MADD/MSUB on arm64.

1. The total size of pkg/android_arm64/ decreases about 4KB,
   excluding cmd/compile/ .

2. There is no regression in the go1 benchmark, excluding noise.
name                     old time/op    new time/op    delta
BinaryTree17-4              16.4s ± 1%     16.5s ± 1%  +0.24%  (p=0.008 n=29+29)
Fannkuch11-4                8.73s ± 0%     8.71s ± 0%  -0.15%  (p=0.000 n=29+29)
FmtFprintfEmpty-4           174ns ± 0%     174ns ± 0%    ~     (all equal)
FmtFprintfString-4          370ns ± 0%     372ns ± 2%  +0.53%  (p=0.007 n=24+30)
FmtFprintfInt-4             419ns ± 0%     419ns ± 0%    ~     (all equal)
FmtFprintfIntInt-4          673ns ± 1%     661ns ± 1%  -1.81%  (p=0.000 n=30+27)
FmtFprintfPrefixedInt-4     806ns ± 0%     805ns ± 0%    ~     (p=0.957 n=28+27)
FmtFprintfFloat-4          1.09µs ± 0%    1.09µs ± 0%  -0.04%  (p=0.001 n=22+30)
FmtManyArgs-4              2.67µs ± 0%    2.68µs ± 0%  +0.03%  (p=0.045 n=29+28)
GobDecode-4                33.2ms ± 1%    32.5ms ± 1%  -2.11%  (p=0.000 n=29+29)
GobEncode-4                29.5ms ± 0%    29.2ms ± 0%  -1.04%  (p=0.000 n=28+28)
Gzip-4                      1.39s ± 2%     1.38s ± 1%  -0.48%  (p=0.023 n=30+30)
Gunzip-4                    139ms ± 0%     139ms ± 0%    ~     (p=0.616 n=30+28)
HTTPClientServer-4          766µs ± 4%     758µs ± 3%  -1.03%  (p=0.013 n=28+29)
JSONEncode-4               49.7ms ± 0%    49.6ms ± 0%  -0.24%  (p=0.000 n=30+30)
JSONDecode-4                266ms ± 0%     268ms ± 1%  +1.07%  (p=0.000 n=29+30)
Mandelbrot200-4            16.6ms ± 0%    16.6ms ± 0%    ~     (p=0.248 n=30+29)
GoParse-4                  15.9ms ± 0%    16.0ms ± 0%  +0.76%  (p=0.000 n=29+29)
RegexpMatchEasy0_32-4       381ns ± 0%     380ns ± 0%  -0.14%  (p=0.000 n=30+30)
RegexpMatchEasy0_1K-4      1.18µs ± 0%    1.19µs ± 1%  +0.30%  (p=0.000 n=29+30)
RegexpMatchEasy1_32-4       357ns ± 0%     357ns ± 0%    ~     (all equal)
RegexpMatchEasy1_1K-4      2.04µs ± 0%    2.05µs ± 0%  +0.50%  (p=0.000 n=26+28)
RegexpMatchMedium_32-4      590ns ± 0%     589ns ± 0%  -0.12%  (p=0.000 n=30+23)
RegexpMatchMedium_1K-4      162µs ± 0%     162µs ± 0%    ~     (p=0.318 n=28+25)
RegexpMatchHard_32-4       9.56µs ± 0%    9.56µs ± 0%    ~     (p=0.072 n=30+29)
RegexpMatchHard_1K-4        287µs ± 0%     287µs ± 0%  -0.02%  (p=0.005 n=28+28)
Revcomp-4                   2.50s ± 0%     2.51s ± 0%    ~     (p=0.246 n=29+29)
Template-4                  312ms ± 1%     313ms ± 1%  +0.46%  (p=0.002 n=30+30)
TimeParse-4                1.68µs ± 0%    1.67µs ± 0%  -0.31%  (p=0.000 n=27+29)
TimeFormat-4               1.66µs ± 0%    1.64µs ± 0%  -0.92%  (p=0.000 n=29+26)
[Geo mean]                  247µs          246µs       -0.15%

name                     old speed      new speed      delta
GobDecode-4              23.1MB/s ± 1%  23.6MB/s ± 0%  +2.17%  (p=0.000 n=29+28)
GobEncode-4              26.0MB/s ± 0%  26.3MB/s ± 0%  +1.05%  (p=0.000 n=28+28)
Gzip-4                   14.0MB/s ± 2%  14.1MB/s ± 1%  +0.47%  (p=0.026 n=30+30)
Gunzip-4                  139MB/s ± 0%   139MB/s ± 0%    ~     (p=0.624 n=30+28)
JSONEncode-4             39.1MB/s ± 0%  39.2MB/s ± 0%  +0.24%  (p=0.000 n=30+30)
JSONDecode-4             7.31MB/s ± 0%  7.23MB/s ± 1%  -1.07%  (p=0.000 n=28+30)
GoParse-4                3.65MB/s ± 0%  3.62MB/s ± 0%  -0.77%  (p=0.000 n=29+29)
RegexpMatchEasy0_32-4    84.0MB/s ± 0%  84.1MB/s ± 0%  +0.18%  (p=0.000 n=28+30)
RegexpMatchEasy0_1K-4     864MB/s ± 0%   861MB/s ± 1%  -0.29%  (p=0.000 n=29+30)
RegexpMatchEasy1_32-4    89.5MB/s ± 0%  89.5MB/s ± 0%    ~     (p=0.841 n=28+28)
RegexpMatchEasy1_1K-4     502MB/s ± 0%   500MB/s ± 0%  -0.51%  (p=0.000 n=29+29)
RegexpMatchMedium_32-4   1.69MB/s ± 0%  1.70MB/s ± 0%  +0.41%  (p=0.000 n=26+30)
RegexpMatchMedium_1K-4   6.31MB/s ± 0%  6.30MB/s ± 0%    ~     (p=0.129 n=30+25)
RegexpMatchHard_32-4     3.35MB/s ± 0%  3.35MB/s ± 0%    ~     (p=0.657 n=30+29)
RegexpMatchHard_1K-4     3.57MB/s ± 0%  3.57MB/s ± 0%    ~     (all equal)
Revcomp-4                 102MB/s ± 0%   101MB/s ± 0%    ~     (p=0.213 n=29+29)
Template-4               6.22MB/s ± 1%  6.19MB/s ± 1%  -0.42%  (p=0.005 n=30+29)
[Geo mean]               24.1MB/s       24.2MB/s       +0.08%

Change-Id: I6c02d3c9975f6bd8bc215cb1fc14d29602b45649
Reviewed-on: https://go-review.googlesource.com/138095
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-28 15:03:17 +00:00
Than McIntosh 31d19c0ba3 test: add testcase for gccgo compile failure 
Also includes a small tweak to test/run.go to allow package names
with Unicode letters (as opposed to just ASCII chars).

Updates #27836

Change-Id: Idbf0bdea24174808cddcb69974dab820eb13e521
Reviewed-on: https://go-review.googlesource.com/138075
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-27 15:01:24 +00:00
David Heuschmann ae9c822f78 cmd/compile: use more specific error message for assignment mismatch 
Show a more specifc error message in the form of "%d variables but %v
returns %d values" if an assignment mismatch occurs with a function
or method call on the right.

Fixes #27595

Change-Id: Ibc97d070662b08f150ac22d686059cf224e012ab
Reviewed-on: https://go-review.googlesource.com/135575
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
 2018-09-27 00:35:06 +00:00
Brian Kessler 9eb53ab9bc cmd/compile: intrinsify math/bits.Mul 
Add SSA rules to intrinsify Mul/Mul64 (AMD64 and ARM64).
SSA rules for other functions and architectures are left as a future
optimization.  Benchmark results on AMD64/ARM64 before and after SSA
implementation are below.

amd64
name     old time/op  new time/op  delta
Add-4    1.78ns ± 0%  1.85ns ±12%     ~     (p=0.397 n=4+5)
Add32-4  1.71ns ± 1%  1.70ns ± 0%     ~     (p=0.683 n=5+5)
Add64-4  1.80ns ± 2%  1.77ns ± 0%   -1.22%  (p=0.048 n=5+5)
Sub-4    1.78ns ± 0%  1.78ns ± 0%     ~     (all equal)
Sub32-4  1.78ns ± 1%  1.78ns ± 0%     ~     (p=1.000 n=5+5)
Sub64-4  1.78ns ± 1%  1.78ns ± 0%     ~     (p=0.968 n=5+4)
Mul-4    11.5ns ± 1%   1.8ns ± 2%  -84.39%  (p=0.008 n=5+5)
Mul32-4  1.39ns ± 0%  1.38ns ± 3%     ~     (p=0.175 n=5+5)
Mul64-4  6.85ns ± 1%  1.78ns ± 1%  -73.97%  (p=0.008 n=5+5)
Div-4    57.1ns ± 1%  56.7ns ± 0%     ~     (p=0.087 n=5+5)
Div32-4  18.0ns ± 0%  18.0ns ± 0%     ~     (all equal)
Div64-4  56.4ns ±10%  53.6ns ± 1%     ~     (p=0.071 n=5+5)

arm64
name      old time/op  new time/op  delta
Add-96    5.51ns ± 0%  5.51ns ± 0%     ~     (all equal)
Add32-96  5.51ns ± 0%  5.51ns ± 0%     ~     (all equal)
Add64-96  5.52ns ± 0%  5.51ns ± 0%     ~     (p=0.444 n=5+5)
Sub-96    5.51ns ± 0%  5.51ns ± 0%     ~     (all equal)
Sub32-96  5.51ns ± 0%  5.51ns ± 0%     ~     (all equal)
Sub64-96  5.51ns ± 0%  5.51ns ± 0%     ~     (all equal)
Mul-96    34.6ns ± 0%   5.0ns ± 0%  -85.52%  (p=0.008 n=5+5)
Mul32-96  4.51ns ± 0%  4.51ns ± 0%     ~     (all equal)
Mul64-96  21.1ns ± 0%   5.0ns ± 0%  -76.26%  (p=0.008 n=5+5)
Div-96    64.7ns ± 0%  64.7ns ± 0%     ~     (all equal)
Div32-96  17.0ns ± 0%  17.0ns ± 0%     ~     (all equal)
Div64-96  53.1ns ± 0%  53.1ns ± 0%     ~     (all equal)

Updates #24813

Change-Id: I9bda6d2102f65cae3d436a2087b47ed8bafeb068
Reviewed-on: https://go-review.googlesource.com/129415
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
 2018-09-26 20:35:57 +00:00
Alberto Donizetti 8c1c6702f1 test: restore binary.BigEndian use in checkbce 
CL 136855 removed the encoding/binary dependency from the checkbce.go
test by defining a local Uint64 to fix the noopt builder; then a more
general mechanism to skip tests on the noopt builder was introduced in
CL 136898, so we can now restore the binary.Uint64 calls in testbce.

Change-Id: I3efbb41be0bfc446a7e638ce6a593371ead2684f
Reviewed-on: https://go-review.googlesource.com/137056
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
 2018-09-24 21:20:51 +00:00
Brad Fitzpatrick b3369063e5 test: skip some tests on noopt builder 
Adds a new build tag "gcflags_noopt" that can be used in test/*.go
tests.

Fixes #27833

Change-Id: I4ea0ccd9e9e58c4639de18645fec81eb24a3a929
Reviewed-on: https://go-review.googlesource.com/136898
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
 2018-09-24 20:56:48 +00:00
Keith Randall 9774fa6f40 cmd/compile: fix precedence order bug 
&^ and << have equal precedence.  Add some parentheses to make sure
we shift before we andnot.

Fixes #27829

Change-Id: Iba8576201f0f7c52bf9795aaa75d15d8f9a76811
Reviewed-on: https://go-review.googlesource.com/136899
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
 2018-09-24 17:43:55 +00:00
Jongmin Kim c22c7607d3 test/bench/garbage: update Benchmarks Game URL to new page 
The existing URL in comment points to an Alioth page which was
deprecated (and not working), so use the new Benchmarks Game URL.

Change-Id: Ifd694382a44a24c44acbed3fe1b17bca6dab998f
Reviewed-on: https://go-review.googlesource.com/136835
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
 2018-09-24 17:11:42 +00:00
Alberto Donizetti 6054fef17f test: fix bcecheck test on noopt builder 
The noopt builder is configured by setting GO_GCFLAGS=-N -l, but the
test/run.go test harness doesn't look at GO_GCFLAGS when processing
"errorcheck" files, it just calls compile:

  cmdline := []string{goTool(), "tool", "compile", /* etc */}

This is working as intended, since it makes the tests more robust and
independent from the environment; errorcheck files are supposed to set
additional building flags, when needed, like in:

  // errorcheck -0 -N -l

The test/bcecheck.go test used to work on the noopt builder (even if
bce is not active on -N -l) because the test was auto-contained and
the file always compiled with optimizations enabled.

In CL 107355, a new bce test dependent on an external package
(encoding.binary) was added. On the noopt builder the external package
is built using -N -l, and this causes a test failure that broke the
noopt builder:

  https://build.golang.org/log/b2be319536285e5807ee9d66d6d0ec4d57433768

To reproduce the failure, one can do:

  $ go install -a -gcflags="-N -l" std
  $ go run run.go -- checkbce.go

This change fixes the noopt builder breakage by removing the bce test
dependency on encoding/binary by defining a local Uint64() function to
be used in the test.

Change-Id: Ife71aab662001442e715c32a0b7d758349a63ff1
Reviewed-on: https://go-review.googlesource.com/136855
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
 2018-09-24 16:54:52 +00:00
Iskander Sharipov 499fbb1a8a cmd/compile/internal/gc: unify self-assignment checks in esc.go 
Move slice self-assign check into isSelfAssign function.
Make debug output consistent for all self-assignment cases.

Change-Id: I0e4cc7b3c1fcaeace7226dd80a0dc1ea97347a55
Reviewed-on: https://go-review.googlesource.com/136276
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-20 09:46:11 +00:00
Robert Griesemer ae37f5a397 cmd/compile: fix error message for &T{} literal mismatch 
See the change and comment in typecheck.go for a detailed explanation.

Fixes #26855.

Change-Id: I7867f948490fc0873b1bd849048cda6acbc36e76
Reviewed-on: https://go-review.googlesource.com/136395
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
 2018-09-20 00:07:35 +00:00
Iskander Sharipov c03d0e4fec cmd/compile/internal/gc: handle arith ops in samesafeexpr 
Teach samesafeexpr to handle arithmetic unary and binary ops.

It makes map lookup optimization possible in

	m[k+1] = append(m[k+1], ...)
	m[-k] = append(m[-k], ...)
	... etc

Does not cover "+" for strings (concatenation).

Change-Id: Ibbb16ac3faf176958da344be1471b06d7cf33a6c
Reviewed-on: https://go-review.googlesource.com/135795
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
 2018-09-19 12:03:58 +00:00
Ben Shi c6bf9a8109 cmd/compile: optimize AMD64's bit wise operation 
Currently "arr[idx] |= 0x80" is compiled to MOVLload->BTSL->MOVLstore.
And this CL optimizes it to a single BTSLconstmodify. Other bit wise
operations with a direct memory operand are also implemented.

1. The size of the executable bin/go decreases about 4KB, and the total size
of pkg/linux_amd64 (excluding cmd/compile) decreases about 0.6KB.

2. There a little improvement in the go1 benchmark test (excluding noise).
name                     old time/op    new time/op    delta
BinaryTree17-4              2.66s ± 4%     2.66s ± 3%    ~     (p=0.596 n=49+49)
Fannkuch11-4                2.38s ± 2%     2.32s ± 2%  -2.69%  (p=0.000 n=50+50)
FmtFprintfEmpty-4          42.7ns ± 4%    43.2ns ± 7%  +1.31%  (p=0.009 n=50+50)
FmtFprintfString-4         71.0ns ± 5%    72.0ns ± 3%  +1.33%  (p=0.000 n=50+50)
FmtFprintfInt-4            80.7ns ± 4%    80.6ns ± 3%    ~     (p=0.931 n=50+50)
FmtFprintfIntInt-4          125ns ± 3%     126ns ± 4%    ~     (p=0.051 n=50+50)
FmtFprintfPrefixedInt-4     158ns ± 1%     142ns ± 3%  -9.84%  (p=0.000 n=36+50)
FmtFprintfFloat-4           215ns ± 4%     212ns ± 4%  -1.23%  (p=0.002 n=50+50)
FmtManyArgs-4               519ns ± 3%     510ns ± 3%  -1.77%  (p=0.000 n=50+50)
GobDecode-4                6.49ms ± 6%    6.52ms ± 5%    ~     (p=0.866 n=50+50)
GobEncode-4                5.93ms ± 8%    6.01ms ± 7%    ~     (p=0.076 n=50+50)
Gzip-4                      222ms ± 4%     224ms ± 8%  +0.80%  (p=0.001 n=50+50)
Gunzip-4                   36.6ms ± 5%    36.4ms ± 4%    ~     (p=0.093 n=50+50)
HTTPClientServer-4         59.1µs ± 1%    58.9µs ± 2%  -0.24%  (p=0.039 n=49+48)
JSONEncode-4               9.23ms ± 4%    9.21ms ± 5%    ~     (p=0.244 n=50+50)
JSONDecode-4               48.8ms ± 4%    48.7ms ± 4%    ~     (p=0.653 n=50+50)
Mandelbrot200-4            3.81ms ± 4%    3.80ms ± 3%    ~     (p=0.834 n=50+50)
GoParse-4                  3.20ms ± 5%    3.19ms ± 5%    ~     (p=0.494 n=50+50)
RegexpMatchEasy0_32-4      78.1ns ± 2%    77.4ns ± 3%  -0.86%  (p=0.005 n=50+50)
RegexpMatchEasy0_1K-4       233ns ± 3%     233ns ± 3%    ~     (p=0.074 n=50+50)
RegexpMatchEasy1_32-4      74.2ns ± 3%    73.4ns ± 3%  -1.06%  (p=0.000 n=50+50)
RegexpMatchEasy1_1K-4       369ns ± 2%     364ns ± 4%  -1.41%  (p=0.000 n=36+50)
RegexpMatchMedium_32-4      109ns ± 4%     107ns ± 3%  -2.06%  (p=0.001 n=50+50)
RegexpMatchMedium_1K-4     31.5µs ± 3%    30.8µs ± 3%  -2.20%  (p=0.000 n=50+50)
RegexpMatchHard_32-4       1.57µs ± 3%    1.56µs ± 2%  -0.57%  (p=0.016 n=50+50)
RegexpMatchHard_1K-4       47.4µs ± 4%    47.0µs ± 3%  -0.82%  (p=0.008 n=50+50)
Revcomp-4                   414ms ± 7%     412ms ± 7%    ~     (p=0.285 n=50+50)
Template-4                 64.3ms ± 4%    62.7ms ± 3%  -2.44%  (p=0.000 n=50+50)
TimeParse-4                 316ns ± 3%     313ns ± 3%    ~     (p=0.122 n=50+50)
TimeFormat-4                291ns ± 3%     293ns ± 3%  +0.80%  (p=0.001 n=50+50)
[Geo mean]                 46.5µs         46.2µs       -0.81%

name                     old speed      new speed      delta
GobDecode-4               118MB/s ± 6%   118MB/s ± 5%    ~     (p=0.863 n=50+50)
GobEncode-4               130MB/s ± 9%   128MB/s ± 8%    ~     (p=0.076 n=50+50)
Gzip-4                   87.4MB/s ± 4%  86.8MB/s ± 7%  -0.78%  (p=0.002 n=50+50)
Gunzip-4                  531MB/s ± 5%   533MB/s ± 4%    ~     (p=0.093 n=50+50)
JSONEncode-4              210MB/s ± 4%   211MB/s ± 5%    ~     (p=0.247 n=50+50)
JSONDecode-4             39.8MB/s ± 4%  39.9MB/s ± 4%    ~     (p=0.654 n=50+50)
GoParse-4                18.1MB/s ± 5%  18.2MB/s ± 5%    ~     (p=0.493 n=50+50)
RegexpMatchEasy0_32-4     410MB/s ± 2%   413MB/s ± 3%  +0.86%  (p=0.004 n=50+50)
RegexpMatchEasy0_1K-4    4.39GB/s ± 3%  4.38GB/s ± 3%    ~     (p=0.063 n=50+50)
RegexpMatchEasy1_32-4     432MB/s ± 3%   436MB/s ± 3%  +1.07%  (p=0.000 n=50+50)
RegexpMatchEasy1_1K-4    2.77GB/s ± 2%  2.81GB/s ± 4%  +1.46%  (p=0.000 n=36+50)
RegexpMatchMedium_32-4   9.16MB/s ± 3%  9.35MB/s ± 4%  +2.09%  (p=0.001 n=50+50)
RegexpMatchMedium_1K-4   32.5MB/s ± 3%  33.2MB/s ± 3%  +2.25%  (p=0.000 n=50+50)
RegexpMatchHard_32-4     20.4MB/s ± 3%  20.5MB/s ± 2%  +0.56%  (p=0.017 n=50+50)
RegexpMatchHard_1K-4     21.6MB/s ± 4%  21.8MB/s ± 3%  +0.83%  (p=0.008 n=50+50)
Revcomp-4                 613MB/s ± 4%   618MB/s ± 7%    ~     (p=0.152 n=48+50)
Template-4               30.2MB/s ± 4%  30.9MB/s ± 3%  +2.49%  (p=0.000 n=50+50)
[Geo mean]                127MB/s        128MB/s       +0.64%

Change-Id: If405198283855d75697f66cf894b2bef458f620e
Reviewed-on: https://go-review.googlesource.com/135422
Reviewed-by: Keith Randall <khr@golang.org>
 2018-09-19 03:00:58 +00:00
Keith Randall c6118af558 cmd/compile: don't do floating point optimization x+0 -> x 
That optimization is not valid if x == -0.

The test is a bit tricky because 0 == -0. We distinguish
0 from -0 with 1/0 == inf, 1/-0 == -inf.

This has been a bug since CL 24790 in Go 1.8. Probably doesn't
warrant a backport.

Fixes #27718

Note: the optimization x-0 -> x is actually valid.
But it's probably best to take it out, so as to not confuse readers.

Change-Id: I99f16a93b45f7406ec8053c2dc759a13eba035fa
Reviewed-on: https://go-review.googlesource.com/135701
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-18 20:27:09 +00:00
fanzha02 a19a83c8ef cmd/compile: optimize math.Float64(32)bits and math.Float64(32)frombits on arm64 
Use float <-> int register moves without conversion instead of stores
and loads to move float <-> int values.

Math package benchmark results.
name                 old time/op  new time/op  delta
Acosh                 153ns ± 0%   147ns ± 0%   -3.92%  (p=0.000 n=10+10)
Asinh                 183ns ± 0%   177ns ± 0%   -3.28%  (p=0.000 n=10+10)
Atanh                 157ns ± 0%   155ns ± 0%   -1.27%  (p=0.000 n=10+10)
Atan2                 118ns ± 0%   117ns ± 1%   -0.59%  (p=0.003 n=10+10)
Cbrt                  119ns ± 0%   114ns ± 0%   -4.20%  (p=0.000 n=10+10)
Copysign             7.51ns ± 0%  6.51ns ± 0%  -13.32%  (p=0.000 n=9+10)
Cos                  73.1ns ± 0%  70.6ns ± 0%   -3.42%  (p=0.000 n=10+10)
Cosh                  119ns ± 0%   121ns ± 0%   +1.68%  (p=0.000 n=10+9)
ExpGo                 154ns ± 0%   149ns ± 0%   -3.05%  (p=0.000 n=9+10)
Expm1                 101ns ± 0%    99ns ± 0%   -1.88%  (p=0.000 n=10+10)
Exp2Go                150ns ± 0%   146ns ± 0%   -2.67%  (p=0.000 n=10+10)
Abs                  7.01ns ± 0%  6.01ns ± 0%  -14.27%  (p=0.000 n=10+9)
Mod                   234ns ± 0%   212ns ± 0%   -9.40%  (p=0.000 n=9+10)
Frexp                34.5ns ± 0%  30.0ns ± 0%  -13.04%  (p=0.000 n=10+10)
Gamma                 112ns ± 0%   111ns ± 0%   -0.89%  (p=0.000 n=10+10)
Hypot                73.6ns ± 0%  68.6ns ± 0%   -6.79%  (p=0.000 n=10+10)
HypotGo              77.1ns ± 0%  72.1ns ± 0%   -6.49%  (p=0.000 n=10+10)
Ilogb                31.0ns ± 0%  28.0ns ± 0%   -9.68%  (p=0.000 n=10+10)
J0                    437ns ± 0%   434ns ± 0%   -0.62%  (p=0.000 n=10+10)
J1                    433ns ± 0%   431ns ± 0%   -0.46%  (p=0.000 n=10+10)
Jn                    927ns ± 0%   922ns ± 0%   -0.54%  (p=0.000 n=10+10)
Ldexp                41.5ns ± 0%  37.0ns ± 0%  -10.84%  (p=0.000 n=9+10)
Log                   124ns ± 0%   118ns ± 0%   -4.84%  (p=0.000 n=10+9)
Logb                 34.0ns ± 0%  32.0ns ± 0%   -5.88%  (p=0.000 n=10+10)
Log1p                 110ns ± 0%   108ns ± 0%   -1.82%  (p=0.000 n=10+10)
Log10                 136ns ± 0%   132ns ± 0%   -2.94%  (p=0.000 n=10+10)
Log2                 51.6ns ± 0%  47.1ns ± 0%   -8.72%  (p=0.000 n=10+10)
Nextafter32          33.0ns ± 0%  30.5ns ± 0%   -7.58%  (p=0.000 n=10+10)
Nextafter64          29.0ns ± 0%  26.5ns ± 0%   -8.62%  (p=0.000 n=10+10)
PowInt                169ns ± 0%   160ns ± 0%   -5.33%  (p=0.000 n=10+10)
PowFrac               375ns ± 0%   361ns ± 0%   -3.73%  (p=0.000 n=10+10)
RoundToEven          14.0ns ± 0%  12.5ns ± 0%  -10.71%  (p=0.000 n=10+10)
Remainder             206ns ± 0%   192ns ± 0%   -6.80%  (p=0.000 n=10+9)
Signbit              6.01ns ± 0%  5.51ns ± 0%   -8.32%  (p=0.000 n=10+9)
Sin                  70.1ns ± 0%  69.6ns ± 0%   -0.71%  (p=0.000 n=10+10)
Sincos               99.1ns ± 0%  99.6ns ± 0%   +0.50%  (p=0.000 n=9+10)
SqrtGoLatency         178ns ± 0%   146ns ± 0%  -17.70%  (p=0.000 n=8+10)
SqrtPrime            9.19µs ± 0%  9.20µs ± 0%   +0.01%  (p=0.000 n=9+9)
Tanh                  125ns ± 1%   127ns ± 0%   +1.36%  (p=0.000 n=10+10)
Y0                    428ns ± 0%   426ns ± 0%   -0.47%  (p=0.000 n=10+10)
Y1                    431ns ± 0%   429ns ± 0%   -0.46%  (p=0.000 n=10+9)
Yn                    906ns ± 0%   901ns ± 0%   -0.55%  (p=0.000 n=10+10)
Float64bits          4.50ns ± 0%  3.50ns ± 0%  -22.22%  (p=0.000 n=10+10)
Float64frombits      4.00ns ± 0%  3.50ns ± 0%  -12.50%  (p=0.000 n=10+9)
Float32bits          4.50ns ± 0%  3.50ns ± 0%  -22.22%  (p=0.002 n=8+10)
Float32frombits      4.00ns ± 0%  3.50ns ± 0%  -12.50%  (p=0.000 n=10+10)

Change-Id: Iba829e15d5624962fe0c699139ea783efeefabc2
Reviewed-on: https://go-review.googlesource.com/129715
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
 2018-09-17 20:49:04 +00:00
Iskander Sharipov 859cf7fc0f cmd/compile/internal/gc: handle array slice self-assign in esc.go 
Instead of skipping all OSLICEARR, skip only ones with non-pointer
array type. For pointers to arrays, it's safe to apply the
self-assignment slicing optimizations.

Refactored the matching code into separate function for readability.

This is an extension to already existing optimization.

On its own, it does not improve any code under std, but
it opens some new optimization opportunities. One
of them is described in the referenced issue.

Updates #7921

Change-Id: I08ac660d3ef80eb15fd7933fb73cf53ded9333ad
Reviewed-on: https://go-review.googlesource.com/133375
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-17 11:14:58 +00:00
Keith Randall b1f656b1ce cmd/compile: fold address calculations into CMPload[const] ops 
Makes go binary smaller by 0.2%.

I noticed this in autogenerated equal methods, and there are
probably a lot of those.

Change-Id: I4e04eb3653fbceb9dd6a4eee97ceab1fa4d10b72
Reviewed-on: https://go-review.googlesource.com/135379
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
 2018-09-14 19:42:09 +00:00
Lynn Boger 8dbd9afbb0 cmd/compile: improve rules for PPC64.rules 
This adds some improvements to the rules for PPC64 to eliminate
unnecessary zero or sign extends, and fix some rule for truncates
which were not always using the correct sign instruction.

This reduces of size of many functions by 1 or 2 instructions and
can improve performance in cases where the execution time depends
on small loops where at least 1 instruction was removed and where that
loop contributes a significant amount of the total execution time.

Included is a testcase for codegen to verify the sign/zero extend
instructions are omitted.

An example of the improvement (strings):
IndexAnyASCII/256:1-16     392ns ± 0%   369ns ± 0%  -5.79%  (p=0.000 n=1+10)
IndexAnyASCII/256:2-16     397ns ± 0%   376ns ± 0%  -5.23%  (p=0.000 n=1+9)
IndexAnyASCII/256:4-16     405ns ± 0%   384ns ± 0%  -5.19%  (p=1.714 n=1+6)
IndexAnyASCII/256:8-16     427ns ± 0%   403ns ± 0%  -5.57%  (p=0.000 n=1+10)
IndexAnyASCII/256:16-16    441ns ± 0%   418ns ± 1%  -5.33%  (p=0.000 n=1+10)
IndexAnyASCII/4096:1-16   5.62µs ± 0%  5.27µs ± 1%  -6.31%  (p=0.000 n=1+10)
IndexAnyASCII/4096:2-16   5.67µs ± 0%  5.29µs ± 0%  -6.67%  (p=0.222 n=1+8)
IndexAnyASCII/4096:4-16   5.66µs ± 0%  5.28µs ± 1%  -6.66%  (p=0.000 n=1+10)
IndexAnyASCII/4096:8-16   5.66µs ± 0%  5.31µs ± 1%  -6.10%  (p=0.000 n=1+10)
IndexAnyASCII/4096:16-16  5.70µs ± 0%  5.33µs ± 1%  -6.43%  (p=0.182 n=1+10)

Change-Id: I739a6132b505936d39001aada5a978ff2a5f0500
Reviewed-on: https://go-review.googlesource.com/129875
Reviewed-by: David Chase <drchase@google.com>
 2018-09-13 18:24:53 +00:00
erifan01 8149db4f64 cmd/compile: intrinsify math.RoundToEven and math.Abs on arm64 
math.RoundToEven can be done by one arm64 instruction FRINTND, intrinsify it to improve performance.
The current pure Go implementation of the function Abs is translated into five instructions on arm64:
str, ldr, and, str, ldr. The intrinsic implementation requires only one instruction, so in terms of
performance, intrinsify it is worthwhile.

Benchmarks:
name           old time/op  new time/op  delta
Abs-8          3.50ns ± 0%  1.50ns ± 0%  -57.14%  (p=0.000 n=10+10)
RoundToEven-8  9.26ns ± 0%  1.50ns ± 0%  -83.80%  (p=0.000 n=10+10)

Change-Id: I9456b26ab282b544dfac0154fc86f17aed96ac3d
Reviewed-on: https://go-review.googlesource.com/116535
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
 2018-09-13 14:52:51 +00:00
fanzha02 d5377c2026 test: fix the wrong test of math.Copysign(c, -1) for arm64 
The CL 132915 added the wrong codegen test for math.Copysign(c, -1),
it should test that AND is not emitted. This CL fixes this error.

Change-Id: Ida1d3d54ebfc7f238abccbc1f70f914e1b5bfd91
Reviewed-on: https://go-review.googlesource.com/134815
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
 2018-09-12 15:34:20 +00:00
Ben Shi 9f2411894b cmd/compile: optimize arm's bit operation 
BFC (Bit Field Clear) was introduced in ARMv7, which can simplify
ANDconst and BICconst. And this CL implements that optimization.

1. The total size of pkg/android_arm decreases about 3KB, excluding
cmd/compile/.

2. There is no regression in the go1 benchmark result, and some
cases (FmtFprintfEmpty-4 and RegexpMatchMedium_32-4) even get
slight improvement.

name                     old time/op    new time/op    delta
BinaryTree17-4              25.3s ± 1%     25.2s ± 1%    ~     (p=0.072 n=30+29)
Fannkuch11-4                13.3s ± 0%     13.3s ± 0%  +0.13%  (p=0.000 n=30+26)
FmtFprintfEmpty-4           407ns ± 0%     394ns ± 0%  -3.19%  (p=0.000 n=26+28)
FmtFprintfString-4          664ns ± 0%     662ns ± 0%  -0.22%  (p=0.000 n=30+30)
FmtFprintfInt-4             712ns ± 0%     706ns ± 0%  -0.79%  (p=0.000 n=30+30)
FmtFprintfIntInt-4         1.06µs ± 0%    1.05µs ± 0%  -0.38%  (p=0.000 n=30+30)
FmtFprintfPrefixedInt-4    1.16µs ± 0%    1.16µs ± 0%  -0.13%  (p=0.000 n=30+29)
FmtFprintfFloat-4          2.24µs ± 0%    2.23µs ± 0%  -0.51%  (p=0.000 n=29+21)
FmtManyArgs-4              4.09µs ± 0%    4.06µs ± 0%  -0.83%  (p=0.000 n=28+30)
GobDecode-4                55.0ms ± 5%    55.4ms ± 5%    ~     (p=0.307 n=30+30)
GobEncode-4                51.2ms ± 1%    51.9ms ± 1%  +1.23%  (p=0.000 n=29+30)
Gzip-4                      2.64s ± 0%     2.60s ± 0%  -1.35%  (p=0.000 n=30+29)
Gunzip-4                    309ms ± 0%     308ms ± 0%  -0.27%  (p=0.000 n=30+30)
HTTPClientServer-4         1.03ms ± 5%    1.02ms ± 4%    ~     (p=0.117 n=30+29)
JSONEncode-4                101ms ± 2%     101ms ± 2%    ~     (p=0.338 n=29+29)
JSONDecode-4                383ms ± 2%     382ms ± 2%    ~     (p=0.751 n=26+30)
Mandelbrot200-4            18.4ms ± 0%    18.4ms ± 0%  -0.10%  (p=0.000 n=29+29)
GoParse-4                  22.6ms ± 0%    22.5ms ± 0%  -0.39%  (p=0.000 n=30+30)
RegexpMatchEasy0_32-4       761ns ± 0%     750ns ± 0%  -1.47%  (p=0.000 n=26+29)
RegexpMatchEasy0_1K-4      4.33µs ± 0%    4.34µs ± 0%  +0.27%  (p=0.000 n=25+28)
RegexpMatchEasy1_32-4       809ns ± 0%     795ns ± 0%  -1.74%  (p=0.000 n=27+25)
RegexpMatchEasy1_1K-4      5.54µs ± 0%    5.53µs ± 0%  -0.18%  (p=0.000 n=29+29)
RegexpMatchMedium_32-4     1.11µs ± 0%    1.08µs ± 0%  -2.78%  (p=0.000 n=27+29)
RegexpMatchMedium_1K-4      255µs ± 0%     255µs ± 0%  -0.02%  (p=0.029 n=30+30)
RegexpMatchHard_32-4       14.7µs ± 0%    14.7µs ± 0%  -0.28%  (p=0.000 n=30+29)
RegexpMatchHard_1K-4        439µs ± 0%     439µs ± 0%    ~     (p=0.907 n=23+27)
Revcomp-4                  41.9ms ± 1%    41.9ms ± 1%    ~     (p=0.230 n=28+30)
Template-4                  522ms ± 1%     528ms ± 1%  +1.25%  (p=0.000 n=30+30)
TimeParse-4                3.34µs ± 0%    3.35µs ± 0%  +0.23%  (p=0.000 n=30+27)
TimeFormat-4               6.06µs ± 0%    6.13µs ± 0%  +1.08%  (p=0.000 n=29+29)
[Geo mean]                  384µs          382µs       -0.37%

name                     old speed      new speed      delta
GobDecode-4              14.0MB/s ± 5%  13.9MB/s ± 5%    ~     (p=0.308 n=30+30)
GobEncode-4              15.0MB/s ± 1%  14.8MB/s ± 1%  -1.22%  (p=0.000 n=29+30)
Gzip-4                   7.36MB/s ± 0%  7.46MB/s ± 0%  +1.35%  (p=0.000 n=30+30)
Gunzip-4                 62.8MB/s ± 0%  63.0MB/s ± 0%  +0.27%  (p=0.000 n=30+30)
JSONEncode-4             19.2MB/s ± 2%  19.2MB/s ± 2%    ~     (p=0.312 n=29+29)
JSONDecode-4             5.05MB/s ± 3%  5.08MB/s ± 2%    ~     (p=0.356 n=29+30)
GoParse-4                2.56MB/s ± 0%  2.57MB/s ± 0%  +0.39%  (p=0.000 n=23+27)
RegexpMatchEasy0_32-4    42.0MB/s ± 0%  42.6MB/s ± 0%  +1.50%  (p=0.000 n=26+28)
RegexpMatchEasy0_1K-4     236MB/s ± 0%   236MB/s ± 0%  -0.27%  (p=0.000 n=25+28)
RegexpMatchEasy1_32-4    39.6MB/s ± 0%  40.2MB/s ± 0%  +1.73%  (p=0.000 n=27+27)
RegexpMatchEasy1_1K-4     185MB/s ± 0%   185MB/s ± 0%  +0.18%  (p=0.000 n=29+29)
RegexpMatchMedium_32-4    900kB/s ± 0%   920kB/s ± 0%  +2.22%  (p=0.000 n=29+29)
RegexpMatchMedium_1K-4   4.02MB/s ± 0%  4.02MB/s ± 0%  +0.07%  (p=0.004 n=30+27)
RegexpMatchHard_32-4     2.17MB/s ± 0%  2.18MB/s ± 0%  +0.46%  (p=0.000 n=30+26)
RegexpMatchHard_1K-4     2.33MB/s ± 0%  2.33MB/s ± 0%    ~     (all equal)
Revcomp-4                60.6MB/s ± 1%  60.7MB/s ± 1%    ~     (p=0.207 n=28+30)
Template-4               3.72MB/s ± 1%  3.67MB/s ± 1%  -1.23%  (p=0.000 n=30+30)
[Geo mean]               12.9MB/s       12.9MB/s       +0.29%

Change-Id: I07f497f8bb476c950dc555491d00c9066fb64a4e
Reviewed-on: https://go-review.googlesource.com/134232
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-11 14:37:51 +00:00
Iskander Sharipov b7f9c640b7 test: extend noescape bytes.Buffer test suite 
Added some more cases that should be guarded against regression.

Change-Id: I9f1dda2fd0be9b6e167ef1cc018fc8cce55c066c
Reviewed-on: https://go-review.googlesource.com/134017
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
 2018-09-07 18:49:12 +00:00
erifan01 204cc14bdd cmd/compile: implement non-constant rotates using ROR on arm64 
Add some rules to match the Go code like:
	y &= 63
	x << y | x >> (64-y)
or
	y &= 63
	x >> y | x << (64-y)
as a ROR instruction. Make math/bits.RotateLeft faster on arm64.

Extends CL 132435 to arm64.

Benchmarks of math/bits.RotateLeftxxN:
name            old time/op       new time/op       delta
RotateLeft-8    3.548750ns +- 1%  2.003750ns +- 0%  -43.54%  (p=0.000 n=8+8)
RotateLeft8-8   3.925000ns +- 0%  3.925000ns +- 0%     ~     (p=1.000 n=8+8)
RotateLeft16-8  3.925000ns +- 0%  3.927500ns +- 0%     ~     (p=0.608 n=8+8)
RotateLeft32-8  3.925000ns +- 0%  2.002500ns +- 0%  -48.98%  (p=0.000 n=8+8)
RotateLeft64-8  3.536250ns +- 0%  2.003750ns +- 0%  -43.34%  (p=0.000 n=8+8)

Change-Id: I77622cd7f39b917427e060647321f5513973232c
Reviewed-on: https://go-review.googlesource.com/122542
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-07 14:52:02 +00:00
Ben Shi 031a35ec84 cmd/compile: optimize 386's comparison 
Optimization of "(CMPconst [0] (ANDL x y)) -> (TESTL x y)" only
get benefits if there is no further use of the result of x&y. A
condition of uses==1 will have slight improvements.

1. The code size of pkg/linux_386 decreases about 300 bytes, excluding
cmd/compile/.

2. The go1 benchmark shows no regression, and even a slight improvement
in test case FmtFprintfEmpty-4, excluding noise.

name                     old time/op    new time/op    delta
BinaryTree17-4              3.34s ± 3%     3.32s ± 2%    ~     (p=0.197 n=30+30)
Fannkuch11-4                3.48s ± 2%     3.47s ± 1%  -0.33%  (p=0.015 n=30+30)
FmtFprintfEmpty-4          46.3ns ± 4%    44.8ns ± 4%  -3.33%  (p=0.000 n=30+30)
FmtFprintfString-4         78.8ns ± 7%    77.3ns ± 5%    ~     (p=0.098 n=30+26)
FmtFprintfInt-4            90.2ns ± 1%    90.0ns ± 7%  -0.23%  (p=0.027 n=18+30)
FmtFprintfIntInt-4          144ns ± 4%     143ns ± 5%    ~     (p=0.945 n=30+29)
FmtFprintfPrefixedInt-4     180ns ± 4%     180ns ± 5%    ~     (p=0.858 n=30+30)
FmtFprintfFloat-4           409ns ± 4%     406ns ± 3%  -0.87%  (p=0.028 n=30+30)
FmtManyArgs-4               611ns ± 5%     608ns ± 4%    ~     (p=0.812 n=30+30)
GobDecode-4                7.30ms ± 5%    7.26ms ± 5%    ~     (p=0.522 n=30+29)
GobEncode-4                6.90ms ± 7%    6.82ms ± 4%    ~     (p=0.086 n=29+28)
Gzip-4                      396ms ± 4%     400ms ± 4%  +0.99%  (p=0.026 n=30+30)
Gunzip-4                   41.1ms ± 3%    41.2ms ± 3%    ~     (p=0.495 n=30+30)
HTTPClientServer-4         63.7µs ± 3%    63.3µs ± 2%    ~     (p=0.113 n=29+29)
JSONEncode-4               16.1ms ± 2%    16.1ms ± 2%  -0.30%  (p=0.041 n=30+30)
JSONDecode-4               60.9ms ± 3%    61.2ms ± 6%    ~     (p=0.187 n=30+30)
Mandelbrot200-4            5.17ms ± 2%    5.19ms ± 3%    ~     (p=0.676 n=30+30)
GoParse-4                  3.28ms ± 3%    3.25ms ± 2%  -0.97%  (p=0.002 n=30+30)
RegexpMatchEasy0_32-4       103ns ± 4%     104ns ± 4%    ~     (p=0.352 n=30+30)
RegexpMatchEasy0_1K-4       849ns ± 2%     845ns ± 2%    ~     (p=0.381 n=30+30)
RegexpMatchEasy1_32-4       113ns ± 4%     113ns ± 4%    ~     (p=0.795 n=30+30)
RegexpMatchEasy1_1K-4      1.03µs ± 3%    1.03µs ± 4%    ~     (p=0.275 n=25+30)
RegexpMatchMedium_32-4      132ns ± 3%     132ns ± 3%    ~     (p=0.970 n=30+30)
RegexpMatchMedium_1K-4     41.4µs ± 3%    41.4µs ± 3%    ~     (p=0.212 n=30+30)
RegexpMatchHard_32-4       2.22µs ± 4%    2.22µs ± 4%    ~     (p=0.399 n=30+30)
RegexpMatchHard_1K-4       67.2µs ± 3%    67.6µs ± 4%    ~     (p=0.359 n=30+30)
Revcomp-4                   1.84s ± 2%     1.83s ± 2%    ~     (p=0.532 n=30+30)
Template-4                 69.1ms ± 4%    68.8ms ± 3%    ~     (p=0.146 n=30+30)
TimeParse-4                 441ns ± 3%     442ns ± 3%    ~     (p=0.154 n=30+30)
TimeFormat-4                413ns ± 3%     414ns ± 3%    ~     (p=0.275 n=30+30)
[Geo mean]                 66.2µs         66.0µs       -0.28%

name                     old speed      new speed      delta
GobDecode-4               105MB/s ± 5%   106MB/s ± 5%    ~     (p=0.514 n=30+29)
GobEncode-4               111MB/s ± 5%   113MB/s ± 4%  +1.37%  (p=0.046 n=28+28)
Gzip-4                   49.1MB/s ± 4%  48.6MB/s ± 4%  -0.98%  (p=0.028 n=30+30)
Gunzip-4                  472MB/s ± 4%   472MB/s ± 3%    ~     (p=0.496 n=30+30)
JSONEncode-4              120MB/s ± 2%   121MB/s ± 2%  +0.29%  (p=0.042 n=30+30)
JSONDecode-4             31.9MB/s ± 3%  31.7MB/s ± 6%    ~     (p=0.186 n=30+30)
GoParse-4                17.6MB/s ± 3%  17.8MB/s ± 2%  +0.98%  (p=0.002 n=30+30)
RegexpMatchEasy0_32-4     309MB/s ± 4%   307MB/s ± 4%    ~     (p=0.501 n=30+30)
RegexpMatchEasy0_1K-4    1.21GB/s ± 2%  1.21GB/s ± 2%    ~     (p=0.301 n=30+30)
RegexpMatchEasy1_32-4     283MB/s ± 4%   282MB/s ± 3%    ~     (p=0.877 n=30+30)
RegexpMatchEasy1_1K-4    1.00GB/s ± 3%  0.99GB/s ± 4%    ~     (p=0.276 n=25+30)
RegexpMatchMedium_32-4   7.54MB/s ± 3%  7.55MB/s ± 3%    ~     (p=0.528 n=30+30)
RegexpMatchMedium_1K-4   24.7MB/s ± 3%  24.7MB/s ± 3%    ~     (p=0.203 n=30+30)
RegexpMatchHard_32-4     14.4MB/s ± 4%  14.4MB/s ± 4%    ~     (p=0.407 n=30+30)
RegexpMatchHard_1K-4     15.3MB/s ± 3%  15.1MB/s ± 4%    ~     (p=0.306 n=30+30)
Revcomp-4                 138MB/s ± 2%   139MB/s ± 2%    ~     (p=0.520 n=30+30)
Template-4               28.1MB/s ± 4%  28.2MB/s ± 3%    ~     (p=0.149 n=30+30)
[Geo mean]               81.5MB/s       81.5MB/s       +0.06%

Change-Id: I7f75425f79eec93cdd8fdd94db13ad4f61b6a2f5
Reviewed-on: https://go-review.googlesource.com/133657
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
 2018-09-07 01:20:45 +00:00
fanzha02 2e5c32518c cmd/compile: optimize math.Copysign on arm64 
Add rewrite rules to optimize math.Copysign() when the second
argument is negative floating point constant.

For example, math.Copysign(c, -2): The previous compile output is
"AND $9223372036854775807, R0, R0; ORR $-9223372036854775808, R0, R0".
The optimized compile output is "ORR $-9223372036854775808, R0, R0"

Math package benchmark results.
name                   old time/op  new time/op  delta
Copysign-8             2.61ns ± 2%  2.49ns ± 0%  -4.55%  (p=0.000 n=10+10)
Cos-8                  43.0ns ± 0%  41.5ns ± 0%  -3.49%  (p=0.000 n=10+10)
Cosh-8                 98.6ns ± 0%  98.1ns ± 0%  -0.51%  (p=0.000 n=10+10)
ExpGo-8                 107ns ± 0%   105ns ± 0%  -1.87%  (p=0.000 n=10+10)
Exp2Go-8                100ns ± 0%   100ns ± 0%  +0.39%  (p=0.000 n=10+8)
Max-8                  6.56ns ± 2%  6.45ns ± 1%  -1.63%  (p=0.002 n=10+10)
Min-8                  6.66ns ± 3%  6.47ns ± 2%  -2.82%  (p=0.006 n=10+10)
Mod-8                   107ns ± 1%   104ns ± 1%  -2.72%  (p=0.000 n=10+10)
Frexp-8                11.5ns ± 1%  11.0ns ± 0%  -4.56%  (p=0.000 n=8+10)
HypotGo-8              19.4ns ± 0%  19.4ns ± 0%  +0.36%  (p=0.019 n=10+10)
Ilogb-8                8.63ns ± 0%  8.51ns ± 0%  -1.36%  (p=0.000 n=10+10)
Jn-8                    584ns ± 0%   585ns ± 0%  +0.17%  (p=0.000 n=7+8)
Ldexp-8                13.8ns ± 0%  13.5ns ± 0%  -2.17%  (p=0.002 n=8+10)
Logb-8                 10.2ns ± 0%   9.9ns ± 0%  -2.65%  (p=0.000 n=10+7)
Nextafter64-8          7.54ns ± 0%  7.51ns ± 0%  -0.37%  (p=0.000 n=10+10)
Remainder-8            73.5ns ± 1%  70.4ns ± 1%  -4.27%  (p=0.000 n=10+10)
SqrtGoLatency-8        79.6ns ± 0%  76.2ns ± 0%  -4.30%  (p=0.000 n=9+10)
Yn-8                    582ns ± 0%   579ns ± 0%  -0.52%  (p=0.000 n=10+10)

Change-Id: I0c9cd1ea87435e7b8bab94b4e79e6e29785f25b1
Reviewed-on: https://go-review.googlesource.com/132915
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
 2018-09-06 19:57:25 +00:00
Iskander Sharipov 9c2be4c22d bytes: remove bootstrap array from Buffer 
Rationale: small buffer optimization does not work and it has
made things slower since 2014. Until we can make it work,
we should prefer simpler code that also turns out to be more
efficient.

With this change, it's possible to use
NewBuffer(make([]byte, 0, bootstrapSize)) to get the desired
stack-allocated initial buffer since escape analysis can
prove the created slice to be non-escaping.

New implementation key points:

    - Zero value bytes.Buffer performs better than before
    - You can have a truly stack-allocated buffer, and it's not even limited to 64 bytes
    - The unsafe.Sizeof(bytes.Buffer{}) is reduced significantly
    - Empty writes don't cause allocations

Buffer benchmarks from bytes package:

    name                       old time/op    new time/op    delta
    ReadString-8                 9.20µs ± 1%    9.22µs ± 1%     ~     (p=0.148 n=10+10)
    WriteByte-8                  28.1µs ± 0%    26.2µs ± 0%   -6.78%  (p=0.000 n=10+10)
    WriteRune-8                  64.9µs ± 0%    65.0µs ± 0%   +0.16%  (p=0.000 n=10+10)
    BufferNotEmptyWriteRead-8     469µs ± 0%     461µs ± 0%   -1.76%  (p=0.000 n=9+10)
    BufferFullSmallReads-8        108µs ± 0%     108µs ± 0%   -0.21%  (p=0.000 n=10+10)

    name                       old speed      new speed      delta
    ReadString-8               3.56GB/s ± 1%  3.55GB/s ± 1%     ~     (p=0.165 n=10+10)
    WriteByte-8                 146MB/s ± 0%   156MB/s ± 0%   +7.26%  (p=0.000 n=9+10)
    WriteRune-8                 189MB/s ± 0%   189MB/s ± 0%   -0.16%  (p=0.000 n=10+10)

    name                       old alloc/op   new alloc/op   delta
    ReadString-8                 32.8kB ± 0%    32.8kB ± 0%     ~     (all equal)
    WriteByte-8                   0.00B          0.00B          ~     (all equal)
    WriteRune-8                   0.00B          0.00B          ~     (all equal)
    BufferNotEmptyWriteRead-8    4.72kB ± 0%    4.67kB ± 0%   -1.02%  (p=0.000 n=10+10)
    BufferFullSmallReads-8       3.44kB ± 0%    3.33kB ± 0%   -3.26%  (p=0.000 n=10+10)

    name                       old allocs/op  new allocs/op  delta
    ReadString-8                   1.00 ± 0%      1.00 ± 0%     ~     (all equal)
    WriteByte-8                    0.00           0.00          ~     (all equal)
    WriteRune-8                    0.00           0.00          ~     (all equal)
    BufferNotEmptyWriteRead-8      3.00 ± 0%      3.00 ± 0%     ~     (all equal)
    BufferFullSmallReads-8         3.00 ± 0%      2.00 ± 0%  -33.33%  (p=0.000 n=10+10)

The most notable thing in go1 benchmarks is reduced allocs in HTTPClientServer (-1 alloc):

    HTTPClientServer-8           64.0 ± 0%      63.0 ± 0%  -1.56%  (p=0.000 n=10+10)

For more explanations and benchmarks see the referenced issue.

Updates #7921

Change-Id: Ica0bf85e1b70fb4f5dc4f6a61045e2cf4ef72aa3
Reviewed-on: https://go-review.googlesource.com/133715
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
 2018-09-06 19:33:18 +00:00
taylorza 4a095b87d3 cmd/compile: don't crash reporting misuse of shadowed built-in function 
The existing implementation causes a compiler panic if a function parameter shadows a built-in function, and then calling that shadowed name.

Fixes #27356
Change-Id: I1ffb6dc01e63c7f499e5f6f75f77ce2318f35bcd
Reviewed-on: https://go-review.googlesource.com/132876
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
 2018-09-06 02:49:21 +00:00
Ben Shi 067dfce21f cmd/compile: optimize ARM's comparision 
Optimize (CMPconst [0] (ADD x y)) to (CMN x y) will only get benefits
when the result of the addition is no longer used, otherwise there
might be even performance drop. And this CL fixes that issue for
CMP/CMN/TST/TEQ.

There is little regression in the go1 benchmark (excluding noise),
and the test case JSONDecode-4 even gets improvement.

name                     old time/op    new time/op    delta
BinaryTree17-4              21.6s ± 1%     21.6s ± 0%  -0.22%  (p=0.013 n=30+30)
Fannkuch11-4                11.1s ± 0%     11.1s ± 0%  +0.11%  (p=0.000 n=30+29)
FmtFprintfEmpty-4           297ns ± 0%     297ns ± 0%  +0.08%  (p=0.007 n=26+28)
FmtFprintfString-4          589ns ± 1%     589ns ± 0%    ~     (p=0.659 n=30+25)
FmtFprintfInt-4             644ns ± 1%     650ns ± 0%  +0.88%  (p=0.000 n=30+24)
FmtFprintfIntInt-4          964ns ± 0%     977ns ± 0%  +1.33%  (p=0.000 n=30+30)
FmtFprintfPrefixedInt-4    1.06µs ± 0%    1.07µs ± 0%  +1.31%  (p=0.000 n=29+27)
FmtFprintfFloat-4          1.89µs ± 0%    1.92µs ± 0%  +1.25%  (p=0.000 n=29+29)
FmtManyArgs-4              3.63µs ± 0%    3.67µs ± 0%  +1.33%  (p=0.000 n=29+27)
GobDecode-4                38.1ms ± 1%    37.9ms ± 1%  -0.60%  (p=0.000 n=29+29)
GobEncode-4                35.3ms ± 2%    35.2ms ± 1%    ~     (p=0.286 n=30+30)
Gzip-4                      2.36s ± 0%     2.37s ± 2%    ~     (p=0.277 n=24+28)
Gunzip-4                    264ms ± 1%     264ms ± 1%    ~     (p=0.104 n=28+30)
HTTPClientServer-4         1.04ms ± 4%    1.02ms ± 4%  -1.65%  (p=0.000 n=28+28)
JSONEncode-4               78.5ms ± 1%    79.6ms ± 1%  +1.34%  (p=0.000 n=27+28)
JSONDecode-4                379ms ± 4%     352ms ± 5%  -7.09%  (p=0.000 n=29+30)
Mandelbrot200-4            17.6ms ± 0%    17.6ms ± 0%    ~     (p=0.206 n=28+29)
GoParse-4                  21.9ms ± 1%    22.1ms ± 1%  +0.87%  (p=0.000 n=28+26)
RegexpMatchEasy0_32-4       631ns ± 0%     641ns ± 0%  +1.63%  (p=0.000 n=29+30)
RegexpMatchEasy0_1K-4      4.11µs ± 0%    4.11µs ± 0%    ~     (p=0.700 n=30+30)
RegexpMatchEasy1_32-4       670ns ± 0%     679ns ± 0%  +1.37%  (p=0.000 n=21+30)
RegexpMatchEasy1_1K-4      5.31µs ± 0%    5.26µs ± 0%  -1.03%  (p=0.000 n=25+28)
RegexpMatchMedium_32-4      905ns ± 0%     906ns ± 0%  +0.14%  (p=0.001 n=30+30)
RegexpMatchMedium_1K-4      192µs ± 0%     191µs ± 0%  -0.45%  (p=0.000 n=29+27)
RegexpMatchHard_32-4       11.8µs ± 0%    11.7µs ± 0%  -0.39%  (p=0.000 n=29+28)
RegexpMatchHard_1K-4        347µs ± 0%     347µs ± 0%    ~     (p=0.084 n=29+30)
Revcomp-4                  37.5ms ± 1%    37.5ms ± 1%    ~     (p=0.279 n=29+29)
Template-4                  519ms ± 2%     519ms ± 2%    ~     (p=0.652 n=28+29)
TimeParse-4                2.83µs ± 0%    2.78µs ± 0%  -1.90%  (p=0.000 n=27+28)
TimeFormat-4               5.79µs ± 0%    5.60µs ± 0%  -3.23%  (p=0.000 n=29+29)
[Geo mean]                  331µs          330µs       -0.16%

name                     old speed      new speed      delta
GobDecode-4              20.1MB/s ± 1%  20.3MB/s ± 1%  +0.61%  (p=0.000 n=29+29)
GobEncode-4              21.7MB/s ± 2%  21.8MB/s ± 1%    ~     (p=0.294 n=30+30)
Gzip-4                   8.23MB/s ± 1%  8.20MB/s ± 2%    ~     (p=0.099 n=26+28)
Gunzip-4                 73.5MB/s ± 1%  73.4MB/s ± 1%    ~     (p=0.107 n=28+30)
JSONEncode-4             24.7MB/s ± 1%  24.4MB/s ± 1%  -1.32%  (p=0.000 n=27+28)
JSONDecode-4             5.13MB/s ± 4%  5.52MB/s ± 5%  +7.65%  (p=0.000 n=29+30)
GoParse-4                2.65MB/s ± 1%  2.63MB/s ± 1%  -0.87%  (p=0.000 n=28+26)
RegexpMatchEasy0_32-4    50.7MB/s ± 0%  49.9MB/s ± 0%  -1.58%  (p=0.000 n=29+29)
RegexpMatchEasy0_1K-4     249MB/s ± 0%   249MB/s ± 0%    ~     (p=0.342 n=30+28)
RegexpMatchEasy1_32-4    47.7MB/s ± 0%  47.1MB/s ± 0%  -1.39%  (p=0.000 n=26+30)
RegexpMatchEasy1_1K-4     193MB/s ± 0%   195MB/s ± 0%  +1.04%  (p=0.000 n=25+28)
RegexpMatchMedium_32-4   1.10MB/s ± 0%  1.10MB/s ± 0%  -0.42%  (p=0.000 n=30+26)
RegexpMatchMedium_1K-4   5.33MB/s ± 0%  5.36MB/s ± 0%  +0.43%  (p=0.000 n=29+29)
RegexpMatchHard_32-4     2.72MB/s ± 0%  2.73MB/s ± 0%  +0.37%  (p=0.000 n=29+30)
RegexpMatchHard_1K-4     2.95MB/s ± 0%  2.95MB/s ± 0%    ~     (all equal)
Revcomp-4                67.8MB/s ± 1%  67.7MB/s ± 1%    ~     (p=0.273 n=29+29)
Template-4               3.74MB/s ± 2%  3.74MB/s ± 2%    ~     (p=0.665 n=28+29)
[Geo mean]               15.2MB/s       15.2MB/s       +0.21%

Change-Id: Ifed1fb8cc02d5ca52c8bc6c21b6b5bf6dbb2701a
Reviewed-on: https://go-review.googlesource.com/132115
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-05 14:54:08 +00:00
Iskander Sharipov 4cf33e361a cmd/compile/internal/gc: fix mayAffectMemory in esc.go 
For OINDEX and other Left+Right nodes, we want the whole
node to be considered as "may affect memory" if either
of Left or Right affect memory. Initial implementation
only considered node as such if both Left and Right were non-safe.

Change-Id: Icfb965a0b4c24d8f83f3722216db068dad2eba95
Reviewed-on: https://go-review.googlesource.com/133275
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
 2018-09-05 14:16:25 +00:00
Iskander Sharipov bcf3e063cc test: remove go:noinline from escape_because.go 
File is compiled with "-l" flag, so go:noinline is redundant.

Change-Id: Ia269f3b9de9466857fc578ba5164613393e82369
Reviewed-on: https://go-review.googlesource.com/133295
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-05 10:45:58 +00:00
Tobias Klauser d7fc2205d4 test: fix nilptr3 check for wasm 
CL 131735 only updated nilptr3.go for the adjusted nil check. Adjust
nilptr3_wasm.go as well.

Change-Id: I4a6257d32bb212666fe768dac53901ea0b051138
Reviewed-on: https://go-review.googlesource.com/133495
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
 2018-09-05 09:57:32 +00:00
Michael Munday f94de9c9fb cmd/compile: make math/bits.RotateLeft{32,64} intrinsics on s390x 
Extends CL 132435 to s390x. s390x has 32- and 64-bit variable
rotate left instructions.

Change-Id: Ic4f1ebb0e0543207ed2fc8c119e0163b428138a5
Reviewed-on: https://go-review.googlesource.com/133035
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-05 08:29:02 +00:00
Ben Shi 0e9f1de0b7 cmd/compile: optimize arm64's comparison 
Add more optimization with TST/CMN.

1. A tiny benchmark shows more than 12% improvement.
TSTCMN-4                    378µs ± 0%     332µs ± 0%  -12.15%  (p=0.000 n=30+27)
(https://github.com/benshi001/ugo1/blob/master/tstcmn_test.go)

2. There is little regression in the go1 benchmark, excluding noise.

name                     old time/op    new time/op    delta
BinaryTree17-4              19.1s ± 0%     19.1s ± 0%    ~     (p=0.994 n=28+29)
Fannkuch11-4                10.0s ± 0%     10.0s ± 0%    ~     (p=0.198 n=30+25)
FmtFprintfEmpty-4           233ns ± 0%     233ns ± 0%  +0.14%  (p=0.002 n=24+30)
FmtFprintfString-4          428ns ± 0%     428ns ± 0%    ~     (all equal)
FmtFprintfInt-4             472ns ± 0%     472ns ± 0%    ~     (all equal)
FmtFprintfIntInt-4          725ns ± 0%     725ns ± 0%    ~     (all equal)
FmtFprintfPrefixedInt-4     889ns ± 0%     888ns ± 0%    ~     (p=0.632 n=28+30)
FmtFprintfFloat-4          1.20µs ± 0%    1.20µs ± 0%  +0.05%  (p=0.001 n=18+30)
FmtManyArgs-4              3.00µs ± 0%    2.99µs ± 0%  -0.07%  (p=0.001 n=27+30)
GobDecode-4                42.1ms ± 0%    42.2ms ± 0%  +0.29%  (p=0.000 n=28+28)
GobEncode-4                38.6ms ± 9%    38.8ms ± 9%    ~     (p=0.912 n=30+30)
Gzip-4                      2.07s ± 1%     2.05s ± 1%  -0.64%  (p=0.000 n=29+30)
Gunzip-4                    175ms ± 0%     175ms ± 0%  -0.15%  (p=0.001 n=30+30)
HTTPClientServer-4          872µs ± 5%     880µs ± 6%    ~     (p=0.196 n=30+29)
JSONEncode-4               88.5ms ± 1%    89.8ms ± 1%  +1.49%  (p=0.000 n=23+24)
JSONDecode-4                393ms ± 1%     390ms ± 1%  -0.89%  (p=0.000 n=28+30)
Mandelbrot200-4            19.5ms ± 0%    19.5ms ± 0%    ~     (p=0.405 n=29+28)
GoParse-4                  19.9ms ± 0%    20.0ms ± 0%  +0.27%  (p=0.000 n=30+30)
RegexpMatchEasy0_32-4       431ns ± 0%     431ns ± 0%    ~     (p=1.000 n=30+30)
RegexpMatchEasy0_1K-4      1.61µs ± 0%    1.61µs ± 0%    ~     (p=0.527 n=26+26)
RegexpMatchEasy1_32-4       443ns ± 0%     443ns ± 0%    ~     (all equal)
RegexpMatchEasy1_1K-4      2.58µs ± 1%    2.58µs ± 1%    ~     (p=0.578 n=27+25)
RegexpMatchMedium_32-4      740ns ± 0%     740ns ± 0%    ~     (p=0.357 n=30+30)
RegexpMatchMedium_1K-4      223µs ± 0%     223µs ± 0%  +0.16%  (p=0.000 n=30+29)
RegexpMatchHard_32-4       12.3µs ± 0%    12.3µs ± 0%    ~     (p=0.236 n=27+27)
RegexpMatchHard_1K-4        371µs ± 0%     371µs ± 0%  +0.09%  (p=0.000 n=30+27)
Revcomp-4                   2.85s ± 0%     2.85s ± 0%    ~     (p=0.057 n=28+25)
Template-4                  408ms ± 1%     409ms ± 1%    ~     (p=0.117 n=29+29)
TimeParse-4                1.93µs ± 0%    1.93µs ± 0%    ~     (p=0.535 n=29+28)
TimeFormat-4               1.99µs ± 0%    1.99µs ± 0%    ~     (p=0.168 n=29+28)
[Geo mean]                  306µs          307µs       +0.07%

name                     old speed      new speed      delta
GobDecode-4              18.3MB/s ± 0%  18.2MB/s ± 0%  -0.31%  (p=0.000 n=28+29)
GobEncode-4              19.9MB/s ± 8%  19.8MB/s ± 9%    ~     (p=0.923 n=30+30)
Gzip-4                   9.39MB/s ± 1%  9.45MB/s ± 1%  +0.65%  (p=0.000 n=29+30)
Gunzip-4                  111MB/s ± 0%   111MB/s ± 0%  +0.15%  (p=0.001 n=30+30)
JSONEncode-4             21.9MB/s ± 1%  21.6MB/s ± 1%  -1.45%  (p=0.000 n=23+23)
JSONDecode-4             4.94MB/s ± 1%  4.98MB/s ± 1%  +0.84%  (p=0.000 n=27+30)
GoParse-4                2.91MB/s ± 0%  2.90MB/s ± 0%  -0.34%  (p=0.000 n=21+22)
RegexpMatchEasy0_32-4    74.1MB/s ± 0%  74.1MB/s ± 0%    ~     (p=0.469 n=29+28)
RegexpMatchEasy0_1K-4     634MB/s ± 0%   634MB/s ± 0%    ~     (p=0.978 n=24+28)
RegexpMatchEasy1_32-4    72.2MB/s ± 0%  72.2MB/s ± 0%    ~     (p=0.064 n=27+29)
RegexpMatchEasy1_1K-4     396MB/s ± 1%   396MB/s ± 1%    ~     (p=0.583 n=27+25)
RegexpMatchMedium_32-4   1.35MB/s ± 0%  1.35MB/s ± 0%    ~     (all equal)
RegexpMatchMedium_1K-4   4.60MB/s ± 0%  4.59MB/s ± 0%  -0.14%  (p=0.000 n=30+26)
RegexpMatchHard_32-4     2.61MB/s ± 0%  2.61MB/s ± 0%    ~     (all equal)
RegexpMatchHard_1K-4     2.76MB/s ± 0%  2.76MB/s ± 0%    ~     (all equal)
Revcomp-4                89.1MB/s ± 0%  89.1MB/s ± 0%    ~     (p=0.059 n=28+25)
Template-4               4.75MB/s ± 1%  4.75MB/s ± 1%    ~     (p=0.106 n=29+29)
[Geo mean]               18.3MB/s       18.3MB/s       -0.07%

Change-Id: I3cd76ce63e84b0c3cebabf9fa3573b76a7343899
Reviewed-on: https://go-review.googlesource.com/124935
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-05 02:51:28 +00:00
Ben Shi b444215116 cmd/compile: optimize ARM64's code with MADD/MSUB 
MADD does MUL-ADD in a single instruction, and MSUB does the
similiar simplification for MUL-SUB.

The CL implements the optimization with MADD/MSUB.

1. The total size of pkg/android_arm64/ decreases about 20KB,
excluding cmd/compile/.

2. The go1 benchmark shows a little improvement for RegexpMatchHard_32-4
and Template-4, excluding noise.

name                     old time/op    new time/op    delta
BinaryTree17-4              16.3s ± 1%     16.5s ± 1%  +1.41%  (p=0.000 n=26+28)
Fannkuch11-4                8.79s ± 1%     8.76s ± 0%  -0.36%  (p=0.000 n=26+28)
FmtFprintfEmpty-4           172ns ± 0%     172ns ± 0%    ~     (all equal)
FmtFprintfString-4          362ns ± 1%     364ns ± 0%  +0.55%  (p=0.000 n=30+30)
FmtFprintfInt-4             416ns ± 0%     416ns ± 0%    ~     (p=0.099 n=22+30)
FmtFprintfIntInt-4          655ns ± 1%     660ns ± 1%  +0.76%  (p=0.000 n=30+30)
FmtFprintfPrefixedInt-4     810ns ± 0%     809ns ± 0%  -0.08%  (p=0.009 n=29+29)
FmtFprintfFloat-4          1.08µs ± 0%    1.09µs ± 0%  +0.61%  (p=0.000 n=30+29)
FmtManyArgs-4              2.70µs ± 0%    2.69µs ± 0%  -0.23%  (p=0.000 n=29+28)
GobDecode-4                32.2ms ± 1%    32.1ms ± 1%  -0.39%  (p=0.000 n=27+26)
GobEncode-4                27.4ms ± 2%    27.4ms ± 1%    ~     (p=0.864 n=28+28)
Gzip-4                      1.53s ± 1%     1.52s ± 1%  -0.30%  (p=0.031 n=29+29)
Gunzip-4                    146ms ± 0%     146ms ± 0%  -0.14%  (p=0.001 n=25+30)
HTTPClientServer-4         1.00ms ± 4%    0.98ms ± 6%  -1.65%  (p=0.001 n=29+30)
JSONEncode-4               67.3ms ± 1%    67.2ms ± 1%    ~     (p=0.520 n=28+28)
JSONDecode-4                329ms ± 5%     330ms ± 4%    ~     (p=0.142 n=30+30)
Mandelbrot200-4            17.3ms ± 0%    17.3ms ± 0%    ~     (p=0.055 n=26+29)
GoParse-4                  16.9ms ± 1%    17.0ms ± 1%  +0.82%  (p=0.000 n=30+30)
RegexpMatchEasy0_32-4       382ns ± 0%     382ns ± 0%    ~     (all equal)
RegexpMatchEasy0_1K-4      1.33µs ± 0%    1.33µs ± 0%  -0.25%  (p=0.000 n=30+27)
RegexpMatchEasy1_32-4       361ns ± 0%     361ns ± 0%  -0.08%  (p=0.002 n=30+28)
RegexpMatchEasy1_1K-4      2.11µs ± 0%    2.09µs ± 0%  -0.54%  (p=0.000 n=30+29)
RegexpMatchMedium_32-4      594ns ± 0%     592ns ± 0%  -0.32%  (p=0.000 n=30+30)
RegexpMatchMedium_1K-4      173µs ± 0%     172µs ± 0%  -0.77%  (p=0.000 n=29+27)
RegexpMatchHard_32-4       10.4µs ± 0%    10.1µs ± 0%  -3.63%  (p=0.000 n=28+27)
RegexpMatchHard_1K-4        306µs ± 0%     301µs ± 0%  -1.64%  (p=0.000 n=29+30)
Revcomp-4                   2.51s ± 1%     2.52s ± 0%  +0.18%  (p=0.017 n=26+27)
Template-4                  394ms ± 3%     382ms ± 3%  -3.22%  (p=0.000 n=28+28)
TimeParse-4                1.67µs ± 0%    1.67µs ± 0%  +0.05%  (p=0.030 n=27+30)
TimeFormat-4               1.72µs ± 0%    1.70µs ± 0%  -0.79%  (p=0.000 n=28+26)
[Geo mean]                  259µs          259µs       -0.33%

name                     old speed      new speed      delta
GobDecode-4              23.8MB/s ± 1%  23.9MB/s ± 1%  +0.40%  (p=0.001 n=27+26)
GobEncode-4              28.0MB/s ± 2%  28.0MB/s ± 1%    ~     (p=0.863 n=28+28)
Gzip-4                   12.7MB/s ± 1%  12.7MB/s ± 1%  +0.32%  (p=0.026 n=29+29)
Gunzip-4                  133MB/s ± 0%   133MB/s ± 0%  +0.15%  (p=0.001 n=24+30)
JSONEncode-4             28.8MB/s ± 1%  28.9MB/s ± 1%    ~     (p=0.475 n=28+28)
JSONDecode-4             5.89MB/s ± 4%  5.87MB/s ± 5%    ~     (p=0.174 n=29+30)
GoParse-4                3.43MB/s ± 0%  3.40MB/s ± 1%  -0.83%  (p=0.000 n=28+30)
RegexpMatchEasy0_32-4    83.6MB/s ± 0%  83.6MB/s ± 0%    ~     (p=0.848 n=28+29)
RegexpMatchEasy0_1K-4     768MB/s ± 0%   770MB/s ± 0%  +0.25%  (p=0.000 n=30+27)
RegexpMatchEasy1_32-4    88.5MB/s ± 0%  88.5MB/s ± 0%    ~     (p=0.086 n=29+29)
RegexpMatchEasy1_1K-4     486MB/s ± 0%   489MB/s ± 0%  +0.54%  (p=0.000 n=30+29)
RegexpMatchMedium_32-4   1.68MB/s ± 0%  1.69MB/s ± 0%  +0.60%  (p=0.000 n=30+23)
RegexpMatchMedium_1K-4   5.90MB/s ± 0%  5.95MB/s ± 0%  +0.85%  (p=0.000 n=18+20)
RegexpMatchHard_32-4     3.07MB/s ± 0%  3.18MB/s ± 0%  +3.72%  (p=0.000 n=29+26)
RegexpMatchHard_1K-4     3.35MB/s ± 0%  3.40MB/s ± 0%  +1.69%  (p=0.000 n=30+30)
Revcomp-4                 101MB/s ± 0%   101MB/s ± 0%  -0.18%  (p=0.018 n=26+27)
Template-4               4.92MB/s ± 4%  5.09MB/s ± 3%  +3.31%  (p=0.000 n=28+28)
[Geo mean]               22.4MB/s       22.6MB/s       +0.62%

Change-Id: I8f304b272785739f57b3c8f736316f658f8c1b2a
Reviewed-on: https://go-review.googlesource.com/129119
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-04 20:41:58 +00:00
Matthew Dempsky f7a633aa79 cmd/compile: use "N variables but M values" error for OAS 
Makes the error message more consistent between OAS and OAS2.

Fixes #26616.

Change-Id: I07ab46c5ef8a37efb2cb557632697f5d1bf789f7
Reviewed-on: https://go-review.googlesource.com/131280
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
 2018-09-04 19:05:56 +00:00
Alexey Naidonov 669fa8f36a cmd/compile: remove unnecessary nil-check 
Removes unnecessary nil-check when referencing offset from an
address. Suggested by Keith Randall in golang/go#27180.

Updates golang/go#27180

Change-Id: I326ed7fda7cfa98b7e4354c811900707fee26021
Reviewed-on: https://go-review.googlesource.com/131735
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
 2018-09-04 17:44:14 +00:00
Iskander Sharipov 67ac554d79 cmd/compile/internal/gc: fix invalid positions for sink nodes in esc.go 
Make OAS2 and OAS2FUNC sink locations point to the assignment position,
not the nth LHS position.

Fixes #26987

Change-Id: Ibeb9df2da754da8b6638fe1e49e813f37515c13c
Reviewed-on: https://go-review.googlesource.com/129315
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-03 16:46:59 +00:00
Michael Munday 6f9b94ab66 cmd/compile: implement OnesCount{8,16,32,64} intrinsics on s390x 
This CL implements the math/bits.OnesCount{8,16,32,64} functions
as intrinsics on s390x using the 'population count' (popcnt)
instruction. This instruction was released as the 'population-count'
facility which uses the same facility bit (45) as the
'distinct-operands' facility which is a pre-requisite for Go on
s390x. We can therefore use it without a feature check.

The s390x popcnt instruction treats a 64 bit register as a vector
of 8 bytes, summing the number of ones in each byte individually.
It then writes the results to the corresponding bytes in the
output register. Therefore to implement OnesCount{16,32,64} we
need to sum the individual byte counts using some extra
instructions. To do this efficiently I've added some additional
pseudo operations to the s390x SSA backend.

Unlike other architectures the new instruction sequence is faster
for OnesCount8, so that is implemented using the intrinsic.

name         old time/op  new time/op  delta
OnesCount    3.21ns ± 1%  1.35ns ± 0%  -58.00%  (p=0.000 n=20+20)
OnesCount8   0.91ns ± 1%  0.81ns ± 0%  -11.43%  (p=0.000 n=20+20)
OnesCount16  1.51ns ± 3%  1.21ns ± 0%  -19.71%  (p=0.000 n=20+17)
OnesCount32  1.91ns ± 0%  1.12ns ± 1%  -41.60%  (p=0.000 n=19+20)
OnesCount64  3.18ns ± 4%  1.35ns ± 0%  -57.52%  (p=0.000 n=20+20)

Change-Id: Id54f0bd28b6db9a887ad12c0d72fcc168ef9c4e0
Reviewed-on: https://go-review.googlesource.com/114675
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
 2018-09-03 14:35:38 +00:00
Iskander Sharipov ff468a43be cmd/compile/internal/gc: better handling of self-assignments in esc.go 
Teach escape analysis to recognize these assignment patterns
as not causing the src to leak:

	val.x = val.y
	val.x[i] = val.y[j]
	val.x1.x2 = val.x1.y2
	... etc

Helps to avoid "leaking param" with assignments showed above.
The implementation is based on somewhat similiar xs=xs[a:b]
special case that is ignored by the escape analysis.

We may figure out more generalized version of this,
but this one looks like a safe step into that direction.

Updates #14858

Change-Id: I6fe5bfedec9c03bdc1d7624883324a523bd11fde
Reviewed-on: https://go-review.googlesource.com/126395
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
 2018-09-03 14:28:51 +00:00
Giovanni Bajo dd5e9b32ff cmd/compile: add testcase for #24876 
This is still not fixed, the testcase reflects that there are still
a few boundchecks. Let's fix the good alternative with an explicit
test though.

Updates #24876

Change-Id: I4da35eb353e19052bd7b69ea6190a69ced8b9b3d
Reviewed-on: https://go-review.googlesource.com/107355
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
 2018-09-02 10:34:51 +00:00
Giovanni Bajo f02cc88f46 test: relax whitespaces matching in codegen tests 
The codegen testsuite uses regexp to parse the syntax, but it doesn't
have a way to tell line comments containing checks from line comments
containing English sentences. This means that any syntax error (that
is, non-matching regexp) is currently ignored and not reported.

There were some tests in memcombine.go that had an extraneous space
and were thus effectively disabled. It would be great if we could
report it as a syntax error, but for now we just punt and swallow the
spaces as a workaround, to avoid the same mistake again.

Fixes #25452

Change-Id: Ic7747a2278bc00adffd0c199ce40937acbbc9cf0
Reviewed-on: https://go-review.googlesource.com/113835
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
 2018-09-02 10:31:37 +00:00
Giovanni Bajo 09ea3c08e8 cmd/compile: in prove, fix fence-post implications for unsigned domain 
Fence-post implications of the form "x-1 >= w && x > min ⇒ x > w"
were not correctly handling unsigned domain, by always checking signed
limits.

This bug was uncovered once we taught prove that len(x) is always
>= 0 in the signed domain.

In the code being miscompiled (s[len(s)-1]), prove checks
whether len(s)-1 >= len(s) in the unsigned domain; if it proves
that this is always false, it can remove the bound check.

Notice that len(s)-1 >= len(s) can be true for len(s) = 0 because
of the wrap-around, so this is something prove should not be
able to deduce.

But because of the bug, the gate condition for the fence-post
implication was len(s) > MinInt64 instead of len(s) > 0; that
condition would be good in the signed domain but not in the
unsigned domain. And since in CL105635 we taught prove that
len(s) >= 0, the condition incorrectly triggered
(len(s) >= 0 > MinInt64) and things were going downfall.

Fixes #27251
Fixes #27289

Change-Id: I3dbcb1955ac5a66a0dcbee500f41e8d219409be5
Reviewed-on: https://go-review.googlesource.com/132495
Reviewed-by: Keith Randall <khr@golang.org>
 2018-08-31 08:54:38 +00:00