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16 Commits

Author SHA1 Message Date
Dmitri Shuralyov
b2fd76ab8d test: migrate remaining files to go:build syntax
Most of the test cases in the test directory use the new go:build syntax
already. Convert the rest. In general, try to place the build constraint
line below the test directive comment in more places.

For #41184.
For #60268.

Change-Id: I11c41a0642a8a26dc2eda1406da908645bbc005b
Cq-Include-Trybots: luci.golang.try:gotip-linux-386-longtest,gotip-linux-amd64-longtest,gotip-windows-amd64-longtest
Reviewed-on: https://go-review.googlesource.com/c/go/+/536236
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-10-19 23:33:25 +00:00
Yi Yang
4ee1d542ed cmd/compile: sparse conditional constant propagation
sparse conditional constant propagation can discover optimization
opportunities that cannot be found by just combining constant folding
and constant propagation and dead code elimination separately.

This is a re-submit of PR#59575, which fix a broken dominance relationship caught by ssacheck

Updates https://github.com/golang/go/issues/59399

Change-Id: I57482dee38f8e80a610aed4f64295e60c38b7a47
GitHub-Last-Rev: 830016f24e
GitHub-Pull-Request: golang/go#60469
Reviewed-on: https://go-review.googlesource.com/c/go/+/498795
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2023-09-12 21:01:50 +00:00
Bryan Mills
02d234e34d Revert "cmd/compile: sparse conditional constant propagation"
This reverts CL 483875.

Reason for revert: appears to cause internal compiler errors on the ssacheck builder.

Change-Id: I662418384291470c1962c417797a5890dd9aa7a4
Reviewed-on: https://go-review.googlesource.com/c/go/+/497855
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Bryan Mills <bcmills@google.com>
2023-05-24 14:39:34 +00:00
Yi Yang
fa50248ce6 cmd/compile: sparse conditional constant propagation
sparse conditional constant propagation can discover optimization opportunities that cannot be found by just combining constant folding and constant propagation and dead code elimination separately.

Updates #59399

Change-Id: Ia954e906480654a6f0cc065d75b5912f96f36b2e
GitHub-Last-Rev: 90fc02db99
GitHub-Pull-Request: golang/go#59575
Reviewed-on: https://go-review.googlesource.com/c/go/+/483875
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
2023-05-24 02:54:03 +00:00
Keith Randall
4a9064ef41 cmd/compile: fix ordering for short-circuiting ops
Make sure the side effects inside short-circuited operations (&& and ||)
happen correctly.

Before this CL, we attached the side effects to the node itself using
exprInPlace. That caused other side effects in sibling expressions
to get reordered with respect to the short circuit side effect.

Instead, rewrite a && b like:

r := a
if r {
  r = b
}

That code we can keep correctly ordered with respect to other
side-effects extracted from part of a big expression.

exprInPlace seems generally unsafe. But this was the only case where
exprInPlace is called not at the top level of an expression, so I
don't think the other uses can actually trigger an issue (there can't
be a sibling expression). TODO: maybe those cases don't need "in
place", and we can retire that function generally.

This CL needed a small tweak to the SSA generation of OIF so that the
short circuit optimization still triggers. The short circuit optimization
looks for triangle but not diamonds, so don't bother allocating a block
if it will be empty.

Go 1 benchmarks are in the noise.

Fixes #30566

Change-Id: I19c04296bea63cbd6ad05f87a63b005029123610
Reviewed-on: https://go-review.googlesource.com/c/go/+/165617
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2019-03-06 20:04:07 +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
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
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
Ian Lance Taylor
f700f89b0b test: add missing copyright header to checkbce.go
Change-Id: Iafeb8e033c876f482caa17cca414fe13b0fadb12
Reviewed-on: https://go-review.googlesource.com/43613
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
2017-05-18 00:05:25 +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
Keith Randall
73f92f9b04 cmd/compile: use len(s)<=cap(s) to remove more bounds checks
When we discover a relation x <= len(s), also discover the relation
x <= cap(s).  That way, in situations like:

a := s[x:]  // tests 0 <= x <= len(s)
b := s[:x]  // tests 0 <= x <= cap(s)

the second check can be eliminated.

Fixes #16813

Change-Id: Ifc037920b6955e43bac1a1eaf6bac63a89cfbd44
Reviewed-on: https://go-review.googlesource.com/33633
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
Reviewed-by: David Chase <drchase@google.com>
2017-02-02 17:45:58 +00:00
Josh Bleecher Snyder
6286188986 cmd/compile: optimize integer "in range" expressions
Use unsigned comparisons to reduce from
two comparisons to one for integer "in range"
checks, such as a <= b && b < c.
We already do this for bounds checks.
Extend it to user code.

This is much easier to do in the front end than SSA.
A back end optimization would be more powerful,
but this is a good start.

This reduces the power of some of SSA prove
inferences (#16653), but those regressions appear
to be rare and not worth holding this CL for.

Fixes #15844.
Fixes #16697.

strconv benchmarks:

name                          old time/op  new time/op   delta
Atof64Decimal-8               41.4ns ± 3%   38.9ns ± 2%   -5.89%  (p=0.000 n=24+25)
Atof64Float-8                 48.5ns ± 0%   46.8ns ± 3%   -3.64%  (p=0.000 n=20+23)
Atof64FloatExp-8              97.7ns ± 4%   93.5ns ± 1%   -4.25%  (p=0.000 n=25+20)
Atof64Big-8                    187ns ± 8%    162ns ± 2%  -13.54%  (p=0.000 n=24+22)
Atof64RandomBits-8             250ns ± 6%    233ns ± 5%   -6.76%  (p=0.000 n=25+25)
Atof64RandomFloats-8           160ns ± 0%    152ns ± 0%   -5.00%  (p=0.000 n=21+22)
Atof32Decimal-8               41.1ns ± 1%   38.7ns ± 2%   -5.86%  (p=0.000 n=24+24)
Atof32Float-8                 46.1ns ± 1%   43.5ns ± 3%   -5.63%  (p=0.000 n=21+24)
Atof32FloatExp-8               101ns ± 4%    100ns ± 2%   -1.59%  (p=0.000 n=24+23)
Atof32Random-8                 136ns ± 3%    133ns ± 3%   -2.83%  (p=0.000 n=22+22)
Atoi-8                        33.8ns ± 3%   30.6ns ± 3%   -9.51%  (p=0.000 n=24+25)
AtoiNeg-8                     31.6ns ± 3%   29.1ns ± 2%   -8.05%  (p=0.000 n=23+24)
Atoi64-8                      48.6ns ± 1%   43.8ns ± 1%   -9.81%  (p=0.000 n=20+23)
Atoi64Neg-8                   47.1ns ± 4%   42.0ns ± 2%  -10.83%  (p=0.000 n=25+25)
FormatFloatDecimal-8           177ns ± 9%    178ns ± 6%     ~     (p=0.460 n=25+25)
FormatFloat-8                  282ns ± 6%    282ns ± 3%     ~     (p=0.954 n=25+22)
FormatFloatExp-8               259ns ± 7%    255ns ± 6%     ~     (p=0.089 n=25+24)
FormatFloatNegExp-8            253ns ± 6%    254ns ± 6%     ~     (p=0.941 n=25+24)
FormatFloatBig-8               340ns ± 6%    341ns ± 8%     ~     (p=0.600 n=22+25)
AppendFloatDecimal-8          79.4ns ± 0%   80.6ns ± 6%     ~     (p=0.861 n=20+25)
AppendFloat-8                  175ns ± 3%    174ns ± 0%     ~     (p=0.722 n=25+20)
AppendFloatExp-8               142ns ± 4%    142ns ± 2%     ~     (p=0.948 n=25+24)
AppendFloatNegExp-8            137ns ± 2%    138ns ± 2%   +0.70%  (p=0.001 n=24+25)
AppendFloatBig-8               218ns ± 3%    218ns ± 4%     ~     (p=0.596 n=25+25)
AppendFloatBinaryExp-8        80.0ns ± 4%   78.0ns ± 1%   -2.43%  (p=0.000 n=24+21)
AppendFloat32Integer-8        82.3ns ± 3%   79.3ns ± 4%   -3.69%  (p=0.000 n=24+25)
AppendFloat32ExactFraction-8   143ns ± 2%    143ns ± 0%     ~     (p=0.177 n=23+19)
AppendFloat32Point-8           175ns ± 3%    175ns ± 3%     ~     (p=0.062 n=24+25)
AppendFloat32Exp-8             139ns ± 2%    137ns ± 4%   -1.05%  (p=0.001 n=24+24)
AppendFloat32NegExp-8          134ns ± 0%    137ns ± 4%   +2.06%  (p=0.000 n=22+25)
AppendFloat64Fixed1-8         97.8ns ± 0%   98.6ns ± 3%     ~     (p=0.711 n=20+25)
AppendFloat64Fixed2-8          110ns ± 3%    110ns ± 5%   -0.45%  (p=0.037 n=24+24)
AppendFloat64Fixed3-8          102ns ± 3%    102ns ± 3%     ~     (p=0.684 n=24+24)
AppendFloat64Fixed4-8          112ns ± 3%    110ns ± 0%   -1.43%  (p=0.000 n=25+18)
FormatInt-8                   3.18µs ± 4%   3.10µs ± 6%   -2.54%  (p=0.001 n=24+25)
AppendInt-8                   1.81µs ± 5%   1.80µs ± 5%     ~     (p=0.648 n=25+25)
FormatUint-8                   812ns ± 6%    816ns ± 6%     ~     (p=0.777 n=25+25)
AppendUint-8                   536ns ± 4%    538ns ± 3%     ~     (p=0.798 n=20+22)
Quote-8                        605ns ± 6%    602ns ± 9%     ~     (p=0.573 n=25+25)
QuoteRune-8                   99.5ns ± 8%  100.2ns ± 7%     ~     (p=0.432 n=25+25)
AppendQuote-8                  361ns ± 3%    363ns ± 4%     ~     (p=0.085 n=25+25)
AppendQuoteRune-8             23.3ns ± 3%   22.4ns ± 2%   -3.79%  (p=0.000 n=25+24)
UnquoteEasy-8                  146ns ± 4%    145ns ± 5%     ~     (p=0.112 n=24+24)
UnquoteHard-8                  804ns ± 6%    771ns ± 6%   -4.10%  (p=0.000 n=25+24)

Change-Id: Ibd384e46e90f1cfa40503c8c6352a54c65b72980
Reviewed-on: https://go-review.googlesource.com/27652
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-08-25 03:49:16 +00:00
Alexandru Moșoi
6c6089b3fd cmd/compile: bce when max and limit are consts
Removes 49 more bound checks in make.bash. For example:

var a[100]int
for i := 0; i < 50; i++ {
  use a[i+25]
}

Change-Id: I85e0130ee5d07f0ece9b17044bba1a2047414ce7
Reviewed-on: https://go-review.googlesource.com/21379
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-11 16:01:22 +00:00
Alexandru Moșoi
8448d3aace cmd/compile: fold CMPconst and SHR
Fold the comparison when the SHR result is small.

Useful for:
- murmur mix like hashing where higher bits are desirable, i.e. hash = uint32(i * C) >> 18
- integer log2 via DeBruijn sequence: http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogDeBruijn

Change-Id: If70ae18cb86f4cc83ab6213f88ced03cc4986156
Reviewed-on: https://go-review.googlesource.com/21514
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-04-07 13:28:13 +00:00
Alexandru Moșoi
1747788c56 cmd/compile: add a pass to print bound checks
Since BCE happens over several passes (opt, loopbce, prove)
it's easy to regress especially with rewriting.

The pass is only activated with special debug flag.

Change-Id: I46205982e7a2751156db8e875d69af6138068f59
Reviewed-on: https://go-review.googlesource.com/21510
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-04-05 12:46:59 +00:00