This belongs to a series of clean-up changes (see below) for cmd/dist.
This is change (5).

These changes include:
(1)  apply minor fixes
(2)  restore behavior of branchtag
(3)  unleash bootstrap optimization for windows
(4)  use standard generated code header
(5)  remove trivial variables + functions
(6)  move functions for the better
(7)  simplify code segments
(8)  use bytes.Buffer for code generation
(9)  rename variables + functions
(10) remove doc.go

Change-Id: I0efd1271b6a70bb9248d82f8a4d869556f4a557e
Reviewed-on: https://go-review.googlesource.com/61011
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This belongs to a series of clean-up changes (see below) for cmd/dist.
This is change (4).

These changes include:
(1)  apply minor fixes
(2)  restore behavior of branchtag
(3)  unleash bootstrap optimization for windows
(4)  use standard generated code header
(5)  remove trivial variables + functions
(6)  move functions for the better
(7)  simplify code segments
(8)  use bytes.Buffer for code generation
(9)  rename variables + functions
(10) remove doc.go

Change-Id: I5e163f89a518f074e58bf2d44597e553c918d7e6
Reviewed-on: https://go-review.googlesource.com/61010
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This belongs to a series of clean-up changes (see below) for cmd/dist.
This is change (3).

These changes include:
(1)  apply minor fixes
(2)  restore behavior of branchtag
(3)  unleash bootstrap optimization for windows
(4)  use standard generated code header
(5)  remove trivial variables + functions
(6)  move functions for the better
(7)  simplify code segments
(8)  use bytes.Buffer for code generation
(9)  rename variables + functions
(10) remove doc.go

Change-Id: I7612bbc3939e6fca3bee4b8e92c528178dd46cd7
Reviewed-on: https://go-review.googlesource.com/61023Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The behavior was changed unintentionally during the conversion from C to Go.
Reviewed-on: https://go-review.googlesource.com/2470

This belongs to a series of clean-up changes (see below) for cmd/dist.
This is change (2).

These changes include:
(1)  apply minor fixes
(2)  restore behavior of branchtag
(3)  unleash bootstrap optimization for windows
(4)  use standard generated code header
(5)  remove trivial variables + functions
(6)  move functions for the better
(7)  simplify code segments
(8)  use bytes.Buffer for code generation
(9)  rename variables + functions
(10) remove doc.go

Change-Id: I53373c7211b35ed68da485c55e510871bfb81267
Reviewed-on: https://go-review.googlesource.com/61022Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This belongs to a series of clean-up changes (see below) for cmd/dist.
This is change (1).

These changes include:
(1)  apply minor fixes
(2)  restore behavior of branchtag
(3)  unleash bootstrap optimization for windows
(4)  use standard generated code header
(5)  remove trivial variables + functions
(6)  move functions for the better
(7)  simplify code segments
(8)  use bytes.Buffer for code generation
(9)  rename variables + functions
(10) remove doc.go

Change-Id: I49e5f2a9b6146e2b60a067da5bac31434ffc9aaf
Reviewed-on: https://go-review.googlesource.com/60650Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

No functional changes.

Change-Id: Ib31bb3f01b515aac6428ec61e0ef02b269623890
Reviewed-on: https://go-review.googlesource.com/62470Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: Idad9cdee36679373ee223ff2bd4c021ea0afcce1
Reviewed-on: https://go-review.googlesource.com/61710Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Updates #21808.

Change-Id: I0314426afcfeed17b1111040110d7f2b0e209526
Reviewed-on: https://go-review.googlesource.com/62430
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #21742

Change-Id: Ib56b092c490c27a4ba7ebdb6391f1511794710b8
Reviewed-on: https://go-review.googlesource.com/61034
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>

Change-Id: I19c1b0e1b238dda82e69bd47459528ed06b55840
Reviewed-on: https://go-review.googlesource.com/62310Reviewed-by: David Crawshaw <crawshaw@golang.org>

Diagnostics guide lists various dimensions of
diagnostics tools and libraries available in Go.
As a follow-up, I will add an entry section where
we navigate user to the right tool depending on
the type of problem they are willing to improve
or understand better.

Change-Id: I4e94b4b834014f51c988103457da84200c7827d9
Reviewed-on: https://go-review.googlesource.com/61693Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

println with no arguments accidentally doesn't print a newline.

Introduced at CL 55097

Fixes #21808

Change-Id: I9fc7b4271b9b31e4c9b6078f055195dc3907b62c
Reviewed-on: https://go-review.googlesource.com/62390
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I4a0fe1c8625e7e9adfd84ac6910da83d0268f928
Reviewed-on: https://go-review.googlesource.com/60130Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This CL adds generic SSA rules to propagate constants through raw bits
conversions between floats and integers. This allows constants to
propagate through some math functions. For example, math.Copysign(0, -1)
is now constant folded to a load of -0.0.

Requires a fix to the ARM assembler which loaded -0.0 as +0.0.

Change-Id: I52649a4691077c7414f19d17bb599a6743c23ac2
Reviewed-on: https://go-review.googlesource.com/62250
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Change-Id: I01f5d3b4748d0ead8642ff3e53d1ae9c4378bcbc
Reviewed-on: https://go-review.googlesource.com/61111Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #21798

Change-Id: Ided31a8b22c220acdeb3938cac41ce8db9a110c3
Reviewed-on: https://go-review.googlesource.com/62290Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

Perm and Shuffle are fundamentally doing the same work.
This change makes Perm's algorithm match Shuffle's.
In addition to allowing developers to switch more
easily between the two methods, it affords a nice speed-up:

name      old time/op  new time/op  delta
Perm3-8   75.7ns ± 1%  51.8ns ± 1%  -31.59%  (p=0.000 n=9+8)
Perm30-8   610ns ± 1%   405ns ± 1%  -33.67%  (p=0.000 n=9+9)

This change alters the output from Perm,
given the same Source and seed.
This is a change from Go 1.0 behavior.
This necessitates updating the regression test.

This also changes the number of calls made to the Source
during Perm, which changes the output of the math/rand examples.

This also slightly perturbs the output of Perm,
nudging it out of the range currently accepted by TestUniformFactorial.
However, it is complete unclear that the helpers relied on
by TestUniformFactorial are correct. That is #21211.
This change updates checkSimilarDistribution to respect
closeEnough for standard deviations, which makes the test pass.
The whole situation is muddy; see #21211 for details.

There is an alternative implementation of Perm
that avoids initializing m, which is more similar
to the existing implementation, plus some optimizations:

func (r *Rand) Perm(n int) []int {
	m := make([]int, n)
	max31 := n
	if n > 1<<31-1-1 {
		max31 = 1<<31 - 1 - 1
	}
	i := 1
	for ; i < max31; i++ {
		j := r.int31n(int32(i + 1))
		m[i] = m[j]
		m[j] = i
	}
	for ; i < n; i++ {
		j := r.Int63n(int64(i + 1))
		m[i] = m[j]
		m[j] = i
	}
	return m
}

This is a tiny bit faster than the implementation
actually used in this change:

name      old time/op  new time/op  delta
Perm3-8   51.8ns ± 1%  50.3ns ± 1%  -2.83%  (p=0.000 n=8+9)
Perm30-8   405ns ± 1%   394ns ± 1%  -2.66%  (p=0.000 n=9+8)

However, 3% in performance doesn't seem worth
having the two algorithms diverge,
nor the reduced readability of this alternative.

Updates #16213.

Change-Id: I11a7441ff8837ee9c241b4c88f7aa905348be781
Reviewed-on: https://go-review.googlesource.com/55972
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Shuffle uses the Fisher-Yates algorithm.

Since this is new API, it affords us the opportunity
to use a much faster Int31n implementation that mostly avoids division.
As a result, BenchmarkPerm30ViaShuffle is
about 30% faster than BenchmarkPerm30,
despite requiring a separate initialization loop
and using function calls to swap elements.

Fixes #20480
Updates #16213
Updates #21211

Change-Id: Ib8956c4bebed9d84f193eb98282ec16ee7c2b2d5
Reviewed-on: https://go-review.googlesource.com/51891
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The existing implementation will panic when month in date string is '---'.

Fixed #21113

Change-Id: I8058ae7a4102e882f8b7e9c65d80936b563265e4
Reviewed-on: https://go-review.googlesource.com/51010
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I143203a9dcf9a4da0e53a3aab6e370244b849296
Reviewed-on: https://go-review.googlesource.com/62270
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Ensure that the implicitly created redirect
for
  "/route"
after
  "/route/"
has been registered doesn't lose the query string information.
A previous attempt (https://golang.org/cl/43779) changed http.Redirect, however, that change broke direct calls to http.Redirect.
To avoid that problem, this change touches ServeMux.Handler only.

Fixes #17841

Change-Id: I303c1b1824615304ae68147e254bb41b0ea339be
Reviewed-on: https://go-review.googlesource.com/61210
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tom Bergan <tombergan@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

Change "yshl" and "yshb" immediate oclass from Yi32 to Yu8.
This forbids:
- negative shift counts
- shift counts that not fit into 8bit

Affects:
  RCL{B,L,Q,W}
  RCR{B,L,Q,W}
  ROL{B,L,Q,W}
  ROR{B,L,Q,W}
  SAL{B,L,Q,W}
  SAR{B,L,Q,W}
  SHL{B,L,Q,W}
  SHR{B,L,Q,W}

Issue #21528 has some additional context about this change.

Change-Id: I60884cb2b41a860820889fcd878ca6f564006b4a
Reviewed-on: https://go-review.googlesource.com/62190
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

The lexer keeps the byte offset and the line for the rune it's currently
on. This was simple enough up until whitespace trimming was introduced.

With whitespace trimming, we might skip over newlines. In that case, the
lexer wasn't properly updating the line counter. Fix it.

Also, TestPos now checks that the line is correct too, which it was
ignoring before. This was necessary to test this scenario in the lexer.

Fixes #21778.

Change-Id: I3880f3adf02662eac8f818d5caa6935cca9cb33b
Reviewed-on: https://go-review.googlesource.com/61870
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The isStar and directory function parameters have been unused ever since
they were introduced. Remove them.

While at it, apply some other minor simplifications, such as simplifying
a HasPrefix if and using an early continue to unindent many lines of
code.

Change-Id: I8d57353e9ec10cdb59c5388cf6152ce0ec17bdba
Reviewed-on: https://go-review.googlesource.com/62030
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Marvin Stenger <marvin.stenger94@gmail.com>

mapaccess and mapdelete functions are already optimized to prefer direct
key comparison instead of tophash checks when key comparison is cheap.

Extended version of golang.org/cl/55235.

AMD64:
name                old time/op    new time/op    delta
MapPopulate/1         42.5ns ± 2%    40.3ns ± 2%  -5.37%  (p=0.000 n=9+10)
MapPopulate/10         558ns ± 1%     556ns ± 1%    ~     (p=0.157 n=10+10)
MapPopulate/100       7.75µs ± 1%    7.66µs ± 2%  -1.19%  (p=0.001 n=10+10)
MapPopulate/1000      92.6µs ± 1%    92.0µs ± 1%  -0.61%  (p=0.016 n=10+8)
MapPopulate/10000      817µs ± 1%     814µs ± 1%    ~     (p=0.247 n=10+10)
MapPopulate/100000    8.02ms ± 1%    7.90ms ± 2%  -1.47%  (p=0.007 n=10+10)

Change-Id: If0eca9931379cbbd37eb753e9bcd2888d8272153
Reviewed-on: https://go-review.googlesource.com/62050
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This reverts commit 84188296 AKA CL 60530.

Fixes #21783

Change-Id: I68038a77de7446dea68419a40dd25982ea6d7df5
Reviewed-on: https://go-review.googlesource.com/62151Reviewed-by: Heschi Kreinick <heschi@google.com>

Change-Id: I0d02e5e44053f02fee3d84c782995ea4ce209a80
Reviewed-on: https://go-review.googlesource.com/62070Reviewed-by: Heschi Kreinick <heschi@google.com>

There shouldn't be any problems setting error's "Orig" (underlying)
type to a separate anonymous interface, as this is already how
go/types defines it.

Change-Id: I44e9c4048ffe362ce329e8306632e38b5ccfecff
Reviewed-on: https://go-review.googlesource.com/61790
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Alan Donovan <adonovan@google.com>

Change-Id: Ia0479f65a6ef033a65acf9ac8692777839a53b8c
Reviewed-on: https://go-review.googlesource.com/61990
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This adds the VFMADD[213|231]SD, VFNMADD[213|231]SD,
VADDSD, VSUBSD instructions

This will allow us to write a fast path for exp_amd64.s where
these optimizations can be applied in a lot of places.

Change-Id: Ide292107ab887bd1e225a1ad60880235b5ed7c61
Reviewed-on: https://go-review.googlesource.com/61810Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Now that all functions have a DW_AT_frame_base defined we can use
DW_OP_fbreg to specify the location of variables and formal parameters,
instead of the DW_OP_call_frame_cfa/DW_OP_consts/DW_OP_plus, saving 2
bytes for every variable and 2 bytes for every formal parameter after
the first one.

Change-Id: I2c7395b67e4a814a0131ab1520df11ca48ff9327
Reviewed-on: https://go-review.googlesource.com/60550
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>

DWARF version 4 allows DW_AT_high_pc to be represented as a constant
offset from DW_AT_low_pc, this can help save up to 7 bytes per
function/lexical scope.

Change-Id: I93638d83638ecad4d0d1bfe27348eae6139820c9
Reviewed-on: https://go-review.googlesource.com/60530
Run-TryBot: Heschi Kreinick <heschi@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>

Instructions added:
  INSERTPS immb, r/m, xmm
  MPSADBW immb, r/m, xmm
  BLENDPD immb, r/m, xmm
  BLENDPS immb, r/m, xmm
  DPPD immb, r/m, xmm
  DPPS immb, r/m, xmm
  MOVNTDQA r/m, xmm
  PACKUSDW r/m, xmm
  PBLENDW immb, r/m, xmm
  PCMPEQQ r/m, xmm
  PCMPGTQ r/m, xmm
  PCMPISTRI immb, r/m, xmm
  PCMPISTRM immb, r/m, xmm
  PMAXSB r/m, xmm
  PMAXSD r/m, xmm
  PMAXUD r/m, xmm
  PMAXUW r/m, xmm
  PMINSB r/m, xmm
  PMINSD r/m, xmm
  PMINUD r/m, xmm
  PMINUW r/m, xmm
  PTEST r/m, xmm
  PCMPESTRM immb, r/m, xmm

Note: only 'optab' table is extended.

`EXTRACTPS immb, xmm, r/m` is not included in this
change due to new ytab set 'yextractps'. This should simplify
code review.

4-operand instructions are a subject of upcoming changes that
make 4-th (and so on) operands explicit.
Related TODO note in asm6.go:
"dont't hide 4op, some version have xmm version".

Part of the mission to add missing amd64 SSE4 instructions to Go asm.

Change-Id: I71716df14a8a5332e866dd0f0d52d43d7714872f
Reviewed-on: https://go-review.googlesource.com/57470
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>

3rd change out of 3 to cover AMD64 SSSE3 instruction set in Go asm.
This commit adds instruction that do require new ytab variable.

Change-Id: I0bc7d9401c9176eb3760c3d59494ef082e97af84
Reviewed-on: https://go-review.googlesource.com/56870
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
Reviewed-by: Russ Cox <rsc@golang.org>

This is the last instruction I found missing in SSE2 set.

It does not reuse 'yprefetch' ytabs due to differences in
operands SRC/DST roles:
- PREFETCHx: ModRM:r/m(r) -> FROM
- CLFLUSH:   ModRM:r/m(w) -> TO

unaryDst map is extended accordingly.

Change-Id: I89e34ebb81cc0ee5f9ebbb1301bad417f7ee437f
Reviewed-on: https://go-review.googlesource.com/56833
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
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Reviewed-by: Russ Cox <rsc@golang.org>

instructions

1st change out of 3 to cover AMD64 SSSE3 instruction set in Go asm.
This commit adds instructions that do not require new named ytab sets.

Change-Id: I0c3dfd8d39c3daa8b7683ab163c63145626d042e
Reviewed-on: https://go-review.googlesource.com/56834
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
Reviewed-by: Russ Cox <rsc@golang.org>

Functions like NewCBCDecrypter, NewCBCEncrypter, NewCFBDecrypter,
NewCFBEncrypter and NewCTR all panic when IV length does not equal block size.
This commit changes NewOFB to panic too, instead of returning nil silently.

Change-Id: Ic4d3ebfad79bb0cf4759fa1c1a400c1a8d043490
Reviewed-on: https://go-review.googlesource.com/61850Reviewed-by: Filippo Valsorda <hi@filippo.io>
Run-TryBot: Filippo Valsorda <hi@filippo.io>
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runtime.makemap will allocate map buckets on the heap for hints larger
than the number of elements a single map bucket can hold.

Do not allocate any map bucket on the stack if it is known at compile time
that hint is larger than the number of elements one map bucket can hold.
This avoids zeroing and reserving memory on the stack that will not be used.

Change-Id: I1a5ab853fb16f6a18d67674a77701bf0cf29b550
Reviewed-on: https://go-review.googlesource.com/60450
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

The compiler and reflect already zero hiter before mapiterinit.

While here expand the documentation for mapiterinit.

Change-Id: I78b05d4d14bf78e8091e5353cdac80ffed30ca1e
Reviewed-on: https://go-review.googlesource.com/60673
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Previously the type was first set to uint8 and then corrected
later in walkrange.

Change-Id: I9e4b597710e8a5fad39dde035df85676bc8d2874
Reviewed-on: https://go-review.googlesource.com/61032
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>