This commit rewrites if-else-if-else chain in scanBasePrefix function as a switch.

Based on Go style guide https://golang.org/doc/effective_go.html#switch

Change-Id: I6392bfd4ad0384f3dc8896de4763bb2164c3eead
GitHub-Last-Rev: 9bd8dfdac03c466bf8cacf3119f6245dfb61c009
GitHub-Pull-Request: golang/go#30621
Reviewed-on: https://go-review.googlesource.com/c/go/+/165619
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Note that this particular combination of properties still fails (EPERM), but it
no longer hangs.

Updates #29789

Change-Id: I29b15b85a25a7acd7ae89ffc5fed074bcdfe0a12
Reviewed-on: https://go-review.googlesource.com/c/go/+/158297
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

If the input was "John Doe", we're definitely missing "<email>", as
"John Doe@domain" isn't a valid email address.

However, if the input was "john.doe", it's possible that the user meant
"john.doe@domain", and not just "john.doe <email>". Make it clear in the
error that either could be the source of the problem.

Fixes #27064.

Change-Id: I1b8f1342775d711823dffc3db974898ee62d3a34
Reviewed-on: https://go-review.googlesource.com/c/go/+/165517
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The change fixes the following deviations between the existing implementation and the Spec:
1. Using pattern instead of "mask" for assertion and iteration in the Pattern Matching Algorithm.
2. Rename "image/vnd.microsoft.icon" to "image/x-icon" and add another signature for the same.
3. Using named strings instead of hexadecimal representation in "application/zip" and "application/x-rar-compressed".
4. Reordering "sniffSignatures" in accordance with the Spec section "Identifying a resource with an unknown MIME type".

In addition to the above fixes, unit tests for Image MIME type group are added.

Fixes #30570

Change-Id: I97d2ae22b426c3c57bf8efd2ed9396c0be983688
Reviewed-on: https://go-review.googlesource.com/c/go/+/165277Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

While parsing inside a struct or an interface, skipping over empty lines
too to collect the next group of comments. We do not need to skip
over more than 1 empty line since gofmt already removes multiple
empty consecutive lines.

Fixes #10858

Change-Id: I0c97b65b5fc44e225e5dc7871ace24f43419ce08
Reviewed-on: https://go-review.googlesource.com/c/go/+/161177
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

TestGdbAutotmpTypes takes more than one minute due to gdb performances.
Therefore, it must be skipped in short mode.

Change-Id: I253ebce62264cc7367c9b0f6ce9c5088a9994641
Reviewed-on: https://go-review.googlesource.com/c/go/+/164339Reviewed-by: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #28558

Change-Id: I0ecd9c47fb017cf4bd44725a83a0016c7bb94633
Reviewed-on: https://go-review.googlesource.com/c/go/+/156478
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This commit add port of runtime/cgo for aix/ppc64.
AIX assembly is different from Linux assembly, therefore gcc_ppc64.S
must be redone for AIX.

Change-Id: I780ebab4ef9c4ce912f4c4d521d8c135b1eebf6e
Reviewed-on: https://go-review.googlesource.com/c/go/+/164002
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This adds benchmarks to test file uploads using PUT requests.

It's designed to complement changes https://golang.org/cl/163599 and
https://golang.org/cl/163737, allowing an easy comparison of
performance before and after these changes are applied.

Updates #30377.
Co-authored-by: Emmanuel Odeke <emm.odeke@gmail.com>

Change-Id: Ib8e692c61e1f7957d88c7101669d4f7fb8110c65
GitHub-Last-Rev: 242622b4fca9f289defa2f268efc31208743e5dd
GitHub-Pull-Request: golang/go#30424
Reviewed-on: https://go-review.googlesource.com/c/go/+/163862
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

And explain that it does this. A minor change probably worth mentioning,
although (#28782) I'd still like to freeze this document against any substantial
changes.

Fix #30568.

Change-Id: I74c56744871cfaf00dc52a9b480ca61d3ed19a6b
Reviewed-on: https://go-review.googlesource.com/c/go/+/165597Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Currently, lineWrapper does not detect if it is printing a line comment or not.
Hence, while wrapping a comment, the new line does not get prefixed with a //.

We add logic to lineWrapper to detect this case and add // accordingly. Block
comments do not need any such handling.

Added tests for both cases.

Fixes #20929

Change-Id: I656037c2d865f31dd853cf9195f43ab7c6e6fc53
Reviewed-on: https://go-review.googlesource.com/c/go/+/163578
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Currently, the pacer assumes the goal growth ratio is always exactly
GOGC/100. But sometimes this isn't the case, like when the heap is
very small (limited by heapminimum). So to placate the pacer, we lie
about the value of heap_marked in such situations.

Right now, these two lies make a truth, but GOGC is about to get more
complicated with the introduction of heap limits.

Rather than introduce more lies into the system to handle this,
introduce the concept of an "effective GOGC", which is the GOGC we're
actually using for pacing (we'll need this concept anyway with heap
limits). This commit changes the pacer to use the effective GOGC
rather than the user-set GOGC. This way, we no longer need to lie
about heap_marked because its true value is incorporated into the
effective GOGC.

Change-Id: I5b005258f937ab184ffcb5e76053abd798d542bd
Reviewed-on: https://go-review.googlesource.com/c/go/+/66092
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>

Currently, the minimum sweep distance is 1MB * GOGC/100. It's been
this way since it was introduced in CL 13043 with no justification.

Since there seems to be no good reason to scale the minimum sweep
distance by GOGC, make the minimum sweep distance just 1MB.

Change-Id: I5320574a23c0eec641e346282aab08a3bbb057da
Reviewed-on: https://go-review.googlesource.com/c/go/+/66091
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>

This slightly rearranges gcSetTriggerRatio to compute the goal before
computing the other controls. This will simplify implementing the heap
limit, which needs to control the absolute goal and flow the rest of
the control parameters from this.

For #16843.

Change-Id: I46b7c1f8b6e4edbee78930fb093b60bd1a03d75e
Reviewed-on: https://go-review.googlesource.com/c/go/+/46750
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>

This was used during the implementation of concurrent runtime.GC() but
now there's nothing that triggers GC unconditionally. Remove this
trigger type and simplify (gcTrigger).test() accordingly.

Change-Id: I17a893c2ed1f661b8146d7783d529f71735c9105
Reviewed-on: https://go-review.googlesource.com/c/go/+/66090
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>

The following corner cases for readCookiesTests are tested now:
 - An extra cookie delimiter ";" at the end of a Cookie header
 - An empty Cookie header

Change-Id: Id8028b448e4182613fb261bf0903efc98cbf4997
Reviewed-on: https://go-review.googlesource.com/c/go/+/164702Reviewed-by: Volker Dobler <dr.volker.dobler@gmail.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

I missed regenerating op_string.go in CL 152537 (adding OINLMARK op).

Change-Id: I929540087b817b6a1b0256c1e65341615e61ef40
Reviewed-on: https://go-review.googlesource.com/c/go/+/165359
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>

With cgo, some syscalls will be called with g == nil or m == nil.
SyscallX functions cannot handle them so they call an equivalent
function in sys_aix_ppc64.s which will directly call this syscall.

Change-Id: I6508ec772b304111330e6833e7db729200af547c
Reviewed-on: https://go-review.googlesource.com/c/go/+/164001
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

I had been finding these over a year or so, but none were big enough
changes to warrant CLs. They're a handful now, so clean them all up in a
single commit.

The smaller bodies get a bit simpler, but most importantly, the larger
bodies get unindented.

Change-Id: I5707a6fee27d4c9ff9efd3d363af575d7a4bf2aa
Reviewed-on: https://go-review.googlesource.com/c/go/+/165340
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Base64-encoding 32 bytes results in a 44-byte string.
While in general a 44-byte string might decode to 33 bytes,
if you take a 44-byte string that actually only encodes 32 bytes,
and you try to decode it into 32 bytes, that should succeed.
Instead it fails trying to do a useless dst[33:] slice operation.
Delete that slice operation.

Noticed while preparing CL 156322.

Change-Id: I8024bf28a65e2638675b980732b2ff91c66c62cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/164628Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fix builder breakage from CL 148958.

This is an inlining test that should be skipped on -N -l.

The inlining also doesn't happen on arm and wasm, so skip the test
there too.

Fixes the noopt builder, the linux-arm builder, and the wasm builder.

Updates #30605

Change-Id: I06b90d595be7185df61db039dd225dc90d6f678f
Reviewed-on: https://go-review.googlesource.com/c/go/+/165339Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Updates #30228
Updates #30240
Updates #30241

Change-Id: Idc311ba77e99909318b5b86f8ef82d4878f73e47
Reviewed-on: https://go-review.googlesource.com/c/go/+/165378
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

Updates #30228
Updates #30241

Change-Id: I6b5f842d00ba273ed241abe55a1ea71c105ec284
Reviewed-on: https://go-review.googlesource.com/c/go/+/165377
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

Two additions are faster than two multiplications and one addition. The
code seems simpler to me too, as it's more obvious that we advance two
destination bytes for each source byte.

name            old time/op  new time/op  delta
Encode/256-8     374ns ± 0%   331ns ± 0%  -11.44%  (p=0.008 n=5+5)
Encode/1024-8   1.47µs ± 0%  1.29µs ± 0%  -11.89%  (p=0.004 n=6+5)
Encode/4096-8   5.85µs ± 1%  5.15µs ± 0%  -11.89%  (p=0.004 n=6+5)
Encode/16384-8  23.3µs ± 0%  20.6µs ± 0%  -11.68%  (p=0.004 n=6+5)

Change-Id: Iabc63616c1d9fded55fa668ff41dd49efeaa2ea4
Reviewed-on: https://go-review.googlesource.com/c/go/+/151198
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: roger peppe <rogpeppe@gmail.com>

After UserCacheDir and UserHomeDir, the only remaining piece which is
commonly needed and portable is a per-user directory to store persistent
files.

For that purpose, UserCacheDir is wrong, as it's meant only for
temporary files. UserHomeDir is also far from ideal, as that clutters
the user's home directory.

Add UserConfigDir, which is implemented in a similar manner to
UserConfigDir.

Fixes #29960.

Change-Id: I7d7a56615103cf76e2b5e2bab2029a6b09d19f0b
Reviewed-on: https://go-review.googlesource.com/c/go/+/160877
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

To retrieve MTU on aix/ppc64, a socket must be created. Previously, this
socket was recreated for each interface and not close at all, causing a
fd leak on software using interface API.

Change-Id: Ib573e234bfce58964935831b68d007bfbd923476
Reviewed-on: https://go-review.googlesource.com/c/go/+/165397Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Make use of the newly-enabled limited midstack inlining.
Similar changes will be done in followup CLs.

name                    old time/op  new time/op  delta
MutexUncontended        19.3ns ± 1%  18.9ns ± 0%   -1.92%  (p=0.000 n=20+19)
MutexUncontended-4      5.24ns ± 0%  4.75ns ± 1%   -9.25%  (p=0.000 n=20+20)
MutexUncontended-16     2.10ns ± 0%  2.05ns ± 0%   -2.38%  (p=0.000 n=15+19)
Mutex                   19.6ns ± 0%  19.3ns ± 1%   -1.92%  (p=0.000 n=20+17)
Mutex-4                 54.6ns ± 5%  52.4ns ± 4%   -4.09%  (p=0.000 n=20+20)
Mutex-16                 133ns ± 5%   139ns ± 2%   +4.23%  (p=0.000 n=20+16)
MutexSlack              33.4ns ± 2%  18.9ns ± 1%  -43.56%  (p=0.000 n=19+20)
MutexSlack-4             206ns ± 5%   225ns ± 8%   +9.12%  (p=0.000 n=20+18)
MutexSlack-16           89.4ns ± 1%  98.4ns ± 1%  +10.10%  (p=0.000 n=18+17)
MutexWork               60.5ns ± 0%  58.2ns ± 3%   -3.75%  (p=0.000 n=12+20)
MutexWork-4              105ns ± 5%   103ns ± 7%   -1.68%  (p=0.007 n=20+20)
MutexWork-16             157ns ± 1%   163ns ± 2%   +3.90%  (p=0.000 n=18+18)
MutexWorkSlack          70.2ns ± 5%  57.7ns ± 1%  -17.81%  (p=0.000 n=19+20)
MutexWorkSlack-4         277ns ±13%   276ns ±13%     ~     (p=0.682 n=20+19)
MutexWorkSlack-16        156ns ± 0%   147ns ± 0%   -5.62%  (p=0.000 n=16+14)
MutexNoSpin              966ns ± 0%   968ns ± 0%   +0.11%  (p=0.029 n=15+20)
MutexNoSpin-4            269ns ± 4%   270ns ± 2%     ~     (p=0.807 n=20+19)
MutexNoSpin-16           122ns ± 0%   120ns ± 4%   -1.63%  (p=0.000 n=19+19)
MutexSpin               3.13µs ± 0%  3.13µs ± 1%   +0.16%  (p=0.004 n=18+20)
MutexSpin-4              826ns ± 1%   832ns ± 2%   +0.74%  (p=0.000 n=19+16)
MutexSpin-16             397ns ± 1%   395ns ± 0%   -0.50%  (p=0.000 n=19+17)
RWMutexUncontended      71.4ns ± 0%  69.5ns ± 0%   -2.72%  (p=0.000 n=16+20)
RWMutexUncontended-4    18.4ns ± 4%  17.5ns ± 0%   -4.92%  (p=0.000 n=20+18)
RWMutexUncontended-16   8.01ns ± 0%  7.92ns ± 0%   -1.15%  (p=0.000 n=18+18)
RWMutexWrite100         24.9ns ± 0%  24.9ns ± 1%     ~     (p=0.099 n=19+20)
RWMutexWrite100-4       46.5ns ± 3%  46.2ns ± 4%     ~     (p=0.253 n=17+19)
RWMutexWrite100-16      68.9ns ± 3%  69.9ns ± 5%   +1.46%  (p=0.012 n=18+20)
RWMutexWrite10          27.1ns ± 0%  27.0ns ± 2%     ~     (p=0.128 n=17+20)
RWMutexWrite10-4        34.8ns ± 1%  34.7ns ± 2%     ~     (p=0.180 n=20+18)
RWMutexWrite10-16       37.5ns ± 2%  37.2ns ± 4%   -0.89%  (p=0.023 n=20+20)
RWMutexWorkWrite100      164ns ± 0%   164ns ± 0%     ~     (p=0.106 n=12+20)
RWMutexWorkWrite100-4    186ns ± 3%   193ns ± 3%   +3.46%  (p=0.000 n=20+20)
RWMutexWorkWrite100-16   204ns ± 2%   210ns ± 3%   +2.96%  (p=0.000 n=18+20)
RWMutexWorkWrite10       153ns ± 0%   153ns ± 0%   -0.20%  (p=0.017 n=20+19)
RWMutexWorkWrite10-4     179ns ± 1%   178ns ± 2%     ~     (p=0.215 n=19+20)
RWMutexWorkWrite10-16    191ns ± 1%   192ns ± 2%     ~     (p=0.166 n=15+19)

linux/amd64 bin/go 14630572 (previous commit 14605947, +24625/+0.17%)

Change-Id: I3f9d1765801fe0b8deb1bc2728b8bba8a7508e23
Reviewed-on: https://go-review.googlesource.com/c/go/+/148958Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Adds a magic header value that is translated to the
Fetch API redirect option, following existing practices.

Updates #26769

Change-Id: Iaf1c9f710de63ea941a360b73f1b4bb725331a35
Reviewed-on: https://go-review.googlesource.com/c/go/+/164666Reviewed-by: Richard Musiol <neelance@gmail.com>
Reviewed-by: Agniva De Sarker <agniva.quicksilver@gmail.com>
Run-TryBot: Agniva De Sarker <agniva.quicksilver@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

When parsing nested object, UnmarshalTypeError does not contain actual
path to nested field in original JSON.

This commit change Field to contain the full path to that field. One
can get the Field name by stripping all the leading path elements.

Fixes #22369

Change-Id: I6969cc08abe8387a351e3fb2944adfaa0dccad2a
Reviewed-on: https://go-review.googlesource.com/c/go/+/145218Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Replace addu with a sll instruction with a definite behavior (sll will discard the upper 32 bits of the 64 bits, then do sign extensions, with certain behavior). It won't have any UNPREDICTABLE expectation.

Fixes #30459

Change-Id: Id79085c28c5cc4f86939b4ef08ef4bff46077c45
GitHub-Last-Rev: 03569796a9a64ed6c7d56a5bca966fc62c89b4ff
GitHub-Pull-Request: golang/go#30461
Reviewed-on: https://go-review.googlesource.com/c/go/+/164758Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Android O seems to require Pipe to call the pipe2 system call.
But kernel version 2.6.23 only supports pipe, not pipe2.
So try pipe2 first, then fall back to pipe.

Fixes #30549

Change-Id: I3c5d86e8e945a5ec8a0ecea7853302952c0476c4
Reviewed-on: https://go-review.googlesource.com/c/go/+/165217
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Ic5b46cfb393f5ba7b91b3fb73b158b0bc238a532
GitHub-Last-Rev: e5c5db51bcc4848d807b0ce45e85c022492b2013
GitHub-Pull-Request: golang/go#30019
Reviewed-on: https://go-review.googlesource.com/c/go/+/160443
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

On aix/ppc64, ar tool must always have -X64 argument if it aims to
create 64 bits archives.

This commit also adds the -D flag handler when calling ar with
gccgotoolchain, to match gccgo version.

Change-Id: I1f5750f8f64a7073780d283567f0b60fc7fa5b97
Reviewed-on: https://go-review.googlesource.com/c/go/+/164417Reviewed-by: Ian Lance Taylor <iant@golang.org>

The commit fixes asmcgocall in order to use the AIX C ABI.

Change-Id: I2a44914a65557a841ea1e12991938af26ad7fd1d
Reviewed-on: https://go-review.googlesource.com/c/go/+/164000
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

EvalSymlinks was mishandling cases like "/x/../../y" or "../../../x"
where there is an extra ".." that goes past the start of the path.

Fixes #30520

Change-Id: I07525575f83009032fa1a99aa270c8d42007d276
Reviewed-on: https://go-review.googlesource.com/c/go/+/164762Reviewed-by: Bryan C. Mills <bcmills@google.com>

Fixes StartTimer's doc with the verb 'be'
that was previously missing in 'can also used'.

Change-Id: I4b3e6103fbf62d676056d32fcce4618536b7c05c
Reviewed-on: https://go-review.googlesource.com/c/go/+/165117Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This method was using a handwritten long multiplication of uint64s.
Since implementation of #24813 we can remove it and replace it
by Mul64 from math/bits.

This brings a small speedup for 64-bit platforms.

Benchmarks on Haswell Celeron 2955U.

benchmark                                  old ns/op     new ns/op     delta
BenchmarkAppendFloat/Decimal-2             127           127           +0.00%
BenchmarkAppendFloat/Float-2               340           317           -6.76%
BenchmarkAppendFloat/Exp-2                 258           233           -9.69%
BenchmarkAppendFloat/NegExp-2              256           231           -9.77%
BenchmarkAppendFloat/Big-2                 402           375           -6.72%
BenchmarkAppendFloat/BinaryExp-2           113           114           +0.88%
BenchmarkAppendFloat/32Integer-2           125           125           +0.00%
BenchmarkAppendFloat/32ExactFraction-2     274           249           -9.12%
BenchmarkAppendFloat/32Point-2             339           317           -6.49%
BenchmarkAppendFloat/32Exp-2               255           229           -10.20%
BenchmarkAppendFloat/32NegExp-2            254           229           -9.84%
BenchmarkAppendFloat/64Fixed1-2            165           154           -6.67%
BenchmarkAppendFloat/64Fixed2-2            184           176           -4.35%
BenchmarkAppendFloat/64Fixed3-2            168           158           -5.95%
BenchmarkAppendFloat/64Fixed4-2            187           177           -5.35%
BenchmarkAppendFloat/Slowpath64-2          84977         84883         -0.11%

Change-Id: If05784e856289b3b7bf136567882e7ee10234756
Reviewed-on: https://go-review.googlesource.com/c/go/+/157717
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

While we're here, delete addWW_g and subWW_g, per the TODO.
They are now obsolete.

Benchmarks on amd64 with -tags=math_big_pure_go.

name                old time/op    new time/op     delta
AddVV/1-8             5.24ns ± 2%     5.12ns ± 1%    -2.11%  (p=0.000 n=82+87)
AddVV/2-8             6.44ns ± 1%     6.33ns ± 2%    -1.82%  (p=0.000 n=77+82)
AddVV/3-8             7.89ns ± 8%     6.97ns ± 4%   -11.71%  (p=0.000 n=100+96)
AddVV/4-8             8.60ns ± 0%     7.72ns ± 4%   -10.24%  (p=0.000 n=90+96)
AddVV/5-8             10.3ns ± 4%      8.5ns ± 1%   -17.02%  (p=0.000 n=96+91)
AddVV/10-8            16.2ns ± 5%     12.8ns ± 1%   -21.11%  (p=0.000 n=97+86)
AddVV/100-8            148ns ± 1%      117ns ± 5%   -21.07%  (p=0.000 n=66+98)
AddVV/1000-8          1.41µs ± 4%     1.13µs ± 3%   -19.90%  (p=0.000 n=97+97)
AddVV/10000-8         14.2µs ± 5%     11.2µs ± 1%   -20.82%  (p=0.000 n=99+84)
AddVV/100000-8         142µs ± 4%      113µs ± 4%   -20.40%  (p=0.000 n=91+92)
SubVV/1-8             5.29ns ± 1%     5.11ns ± 0%    -3.30%  (p=0.000 n=87+88)
SubVV/2-8             6.36ns ± 4%     6.33ns ± 2%    -0.56%  (p=0.002 n=98+73)
SubVV/3-8             7.58ns ± 5%     6.98ns ± 4%    -8.01%  (p=0.000 n=97+91)
SubVV/4-8             8.61ns ± 3%     7.98ns ± 2%    -7.31%  (p=0.000 n=95+83)
SubVV/5-8             10.6ns ± 2%      8.5ns ± 1%   -19.56%  (p=0.000 n=79+89)
SubVV/10-8            16.3ns ± 4%     12.7ns ± 1%   -21.97%  (p=0.000 n=98+82)
SubVV/100-8            124ns ± 1%      118ns ± 1%    -4.83%  (p=0.000 n=85+81)
SubVV/1000-8          1.14µs ± 5%     1.12µs ± 2%    -1.17%  (p=0.000 n=97+81)
SubVV/10000-8         11.6µs ±10%     11.2µs ± 1%    -3.39%  (p=0.000 n=100+84)
SubVV/100000-8         114µs ± 6%      114µs ± 5%      ~     (p=0.396 n=83+94)
AddVW/1-8             4.04ns ± 4%     4.34ns ± 4%    +7.57%  (p=0.000 n=96+98)
AddVW/2-8             4.34ns ± 5%     4.40ns ± 5%    +1.40%  (p=0.000 n=99+98)
AddVW/3-8             5.43ns ± 0%     5.54ns ± 2%    +1.97%  (p=0.000 n=85+94)
AddVW/4-8             6.23ns ± 1%     6.18ns ± 2%    -0.66%  (p=0.000 n=77+78)
AddVW/5-8             6.78ns ± 2%     6.90ns ± 4%    +1.77%  (p=0.000 n=80+99)
AddVW/10-8            10.5ns ± 4%      9.9ns ± 1%    -5.77%  (p=0.000 n=97+69)
AddVW/100-8            114ns ± 3%       91ns ± 0%   -20.38%  (p=0.000 n=98+77)
AddVW/1000-8          1.12µs ± 1%     0.87µs ± 1%   -22.80%  (p=0.000 n=82+68)
AddVW/10000-8         11.2µs ± 2%      8.5µs ± 5%   -23.85%  (p=0.000 n=85+100)
AddVW/100000-8         112µs ± 2%       85µs ± 5%   -24.22%  (p=0.000 n=71+96)
SubVW/1-8             4.09ns ± 2%     4.18ns ± 4%    +2.32%  (p=0.000 n=78+96)
SubVW/2-8             4.59ns ± 5%     4.52ns ± 7%    -1.54%  (p=0.000 n=98+94)
SubVW/3-8             5.41ns ±10%     5.55ns ± 1%    +2.48%  (p=0.000 n=100+89)
SubVW/4-8             6.51ns ± 2%     6.19ns ± 0%    -4.85%  (p=0.000 n=97+81)
SubVW/5-8             7.25ns ± 3%     6.90ns ± 4%    -4.93%  (p=0.000 n=97+96)
SubVW/10-8            10.6ns ± 4%      9.8ns ± 2%    -7.32%  (p=0.000 n=95+96)
SubVW/100-8           90.4ns ± 0%     90.8ns ± 0%    +0.43%  (p=0.000 n=83+78)
SubVW/1000-8           853ns ± 4%      857ns ± 2%    +0.42%  (p=0.000 n=100+98)
SubVW/10000-8         8.52µs ± 4%     8.53µs ± 2%      ~     (p=0.061 n=99+97)
SubVW/100000-8        84.8µs ± 5%     84.2µs ± 2%    -0.78%  (p=0.000 n=99+93)
AddMulVVW/1-8         8.73ns ± 0%     5.33ns ± 3%   -38.91%  (p=0.000 n=91+96)
AddMulVVW/2-8         14.8ns ± 3%      6.5ns ± 2%   -56.33%  (p=0.000 n=100+79)
AddMulVVW/3-8         18.6ns ± 2%      7.8ns ± 5%   -57.84%  (p=0.000 n=89+96)
AddMulVVW/4-8         24.0ns ± 2%      9.8ns ± 0%   -59.09%  (p=0.000 n=95+67)
AddMulVVW/5-8         29.0ns ± 2%     11.5ns ± 5%   -60.44%  (p=0.000 n=90+97)
AddMulVVW/10-8        54.1ns ± 0%     18.8ns ± 1%   -65.37%  (p=0.000 n=82+84)
AddMulVVW/100-8        508ns ± 2%      165ns ± 4%   -67.62%  (p=0.000 n=72+98)
AddMulVVW/1000-8      4.96µs ± 3%     1.55µs ± 1%   -68.86%  (p=0.000 n=99+91)
AddMulVVW/10000-8     50.0µs ± 4%     15.5µs ± 4%   -68.95%  (p=0.000 n=97+97)
AddMulVVW/100000-8     491µs ± 1%      156µs ± 8%   -68.22%  (p=0.000 n=79+95)

Change-Id: I4c6ae0b4065f371aea8103f6a85d9e9274bf01d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/164965
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Fixes #30555

Change-Id: Ib894b4f3cdba23a18a69c9470cf69ceb83591a4d
Reviewed-on: https://go-review.googlesource.com/c/go/+/165057
Run-TryBot: Baokun Lee <nototon@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Special case shifts by zero.
Provide hints to the compiler that shifts are bounded.

There are no existing benchmarks for shifts,
but the Float implementation uses shifts,
so we can use those.

Benchmarks on amd64 with -tags=math_big_pure_go.

name                  old time/op    new time/op    delta
FloatString/100-8        869ns ± 3%     872ns ± 4%   +0.40%  (p=0.001 n=94+83)
FloatString/1000-8      26.5µs ± 1%    26.4µs ± 1%   -0.46%  (p=0.000 n=87+96)
FloatString/10000-8     2.18ms ± 2%    2.18ms ± 2%     ~     (p=0.687 n=90+89)
FloatString/100000-8     200ms ± 7%     197ms ± 5%   -1.47%  (p=0.000 n=100+90)
FloatAdd/10-8           65.9ns ± 4%    64.0ns ± 4%   -2.94%  (p=0.000 n=92+93)
FloatAdd/100-8          71.3ns ± 4%    67.4ns ± 4%   -5.51%  (p=0.000 n=96+93)
FloatAdd/1000-8          128ns ± 1%     121ns ± 0%   -5.69%  (p=0.000 n=91+80)
FloatAdd/10000-8         718ns ± 4%     626ns ± 4%  -12.83%  (p=0.000 n=99+99)
FloatAdd/100000-8       6.43µs ± 3%    5.50µs ± 1%  -14.50%  (p=0.000 n=98+83)
FloatSub/10-8           57.7ns ± 2%    57.0ns ± 4%   -1.20%  (p=0.000 n=89+96)
FloatSub/100-8          59.9ns ± 3%    58.7ns ± 4%   -2.10%  (p=0.000 n=100+98)
FloatSub/1000-8         94.5ns ± 1%    88.6ns ± 0%   -6.16%  (p=0.000 n=74+70)
FloatSub/10000-8         456ns ± 1%     416ns ± 5%   -8.83%  (p=0.000 n=87+95)
FloatSub/100000-8       4.00µs ± 1%    3.57µs ± 1%  -10.87%  (p=0.000 n=68+85)
FloatSqrt/64-8           585ns ± 1%     579ns ± 1%   -0.99%  (p=0.000 n=92+90)
FloatSqrt/128-8         1.26µs ± 1%    1.23µs ± 2%   -2.42%  (p=0.000 n=91+81)
FloatSqrt/256-8         1.45µs ± 3%    1.40µs ± 1%   -3.61%  (p=0.000 n=96+90)
FloatSqrt/1000-8        4.03µs ± 1%    3.91µs ± 1%   -3.05%  (p=0.000 n=90+93)
FloatSqrt/10000-8       48.0µs ± 0%    47.3µs ± 1%   -1.55%  (p=0.000 n=90+90)
FloatSqrt/100000-8      1.23ms ± 3%    1.22ms ± 4%   -1.00%  (p=0.000 n=99+99)
FloatSqrt/1000000-8     96.7ms ± 4%    98.0ms ±10%     ~     (p=0.322 n=89+99)

Change-Id: I0f941c05b7c324256d7f0674559b6ba906e92ba8
Reviewed-on: https://go-review.googlesource.com/c/go/+/164967
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>