Use movups to copy 16 bytes at a time.
Results (haswell):

name            old time/op  new time/op  delta
CopyFat8-48     0.62ns ± 3%  0.63ns ± 3%     ~     (p=0.535 n=20+20)
CopyFat12-48    0.92ns ± 2%  0.93ns ± 3%     ~     (p=0.594 n=17+18)
CopyFat16-48    1.23ns ± 2%  1.23ns ± 2%     ~     (p=0.839 n=20+19)
CopyFat24-48    1.85ns ± 2%  1.84ns ± 0%   -0.48%  (p=0.014 n=19+20)
CopyFat32-48    2.45ns ± 0%  2.45ns ± 1%     ~     (p=1.000 n=16+16)
CopyFat64-48    3.30ns ± 2%  2.14ns ± 1%  -35.00%  (p=0.000 n=20+18)
CopyFat128-48   6.05ns ± 0%  3.98ns ± 0%  -34.22%  (p=0.000 n=18+17)
CopyFat256-48   11.9ns ± 3%   7.7ns ± 0%  -35.87%  (p=0.000 n=20+17)
CopyFat512-48   23.0ns ± 2%  15.1ns ± 2%  -34.52%  (p=0.000 n=20+18)
CopyFat1024-48  44.8ns ± 1%  29.8ns ± 2%  -33.48%  (p=0.000 n=17+19)

Change-Id: I8a78773c656d400726a020894461e00c59f896bf
Reviewed-on: https://go-review.googlesource.com/14836
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Change-Id: I2e74e39628285e2fecaab712be6cff230619a6c2
Reviewed-on: https://go-review.googlesource.com/14778Reviewed-by: Alan Donovan <adonovan@google.com>

Instead of computing the final adjustment factor as a power of 10,
it's more efficient to split 10**e into 2**e * 5**e . Powers of 2
are trivially added to the Float exponent, and powers of 5 are
smaller and thus faster to compute.

Also, use a table of uint64 values rather than float64 values for
initial power value. uint64 values appear to be faster to convert
to Floats (useful for small exponents).

Added two small benchmarks to confirm that there's no regresssion.

benchmark                         old ns/op     new ns/op     delta
BenchmarkParseFloatSmallExp-8     17543         16220         -7.54%
BenchmarkParseFloatLargeExp-8     60865         59996         -1.43%

Change-Id: I3efd7556b023316f86f334137a67fe0c6d52f8ef
Reviewed-on: https://go-review.googlesource.com/14782Reviewed-by: Alan Donovan <adonovan@google.com>

https://go-review.googlesource.com/#/c/13778/ fixed this issue in math/big.
Remove restriction in compiler.

Fixes #11326.

Change-Id: I1429d0dd0d79431706c65616413373fff58f081e
Reviewed-on: https://go-review.googlesource.com/14830Reviewed-by: Rob Pike <r@golang.org>

This change addresses an integer underflow appearing only on systems
using a 32-bit int type. The patch addresses the problem by limiting the
length of unknown chunks to 0x7fffffff. This value appears to already be
checked for when parsing other chunk types, so the bug shouldn't appear
elsewhere in the package. The PNG spec recommends the maximum size for
any chunk to remain under 2^31, so this shouldn't cause errors with
valid images.

Fixes #12687

Change-Id: I17f0e1683515532c661cf2b0b2bc65309d1b7bb7
Reviewed-on: https://go-review.googlesource.com/14766Reviewed-by: Nigel Tao <nigeltao@golang.org>

A panic was in place for an impossible condition that turned
out to be possible if one used a macro to define a macro.

Another go-fuzz "win".

Fixes #12654.

Change-Id: I0a7bb0f0eabb260c986bf7a2288860c78d8db1af
Reviewed-on: https://go-review.googlesource.com/14777Reviewed-by: Andrew Gerrand <adg@golang.org>

Generate slices of method *Sig(nature)s instead of linked lists.
Remove custom lsort function in favor of sort.Interface.

Eliminates another use of stringsCompare.

Passes go build -a -toolexec 'toolstash -cmp' std cmd.

Change-Id: I9ed1664b7f55be9e967dd7196e396a76f6ea3422
Reviewed-on: https://go-review.googlesource.com/14559Reviewed-by: Dave Cheney <dave@cheney.net>

Recent changes caused vet to build the binary for each Test function.
This is wasteful and will become only more so as more tests are added.
Use testing.Main to build only once.

Verified that compilation errors still appear if the binary cannot be
built.

Before:
	real	0m11.169s
	user	0m18.328s
	sys	0m2.152s

After:
	real	0m5.132s
	user	0m9.404s
	sys	0m1.168s

Of course if the compiler were fast we might not notice, but vet is
a big program and growing bigger all the time, as are the tests.

Change-Id: I209a8fdcace94bc5cec946f5dd365d7191f44c02
Reviewed-on: https://go-review.googlesource.com/14822Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I97ba31e758d3396842ad99a08af696e49a5f1a7d
Reviewed-on: https://go-review.googlesource.com/13954
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

This means bringing over the examples flag and sorting doc.go.

Subsequent changes will generalize the examples flag to a general
test naming flag, but let's start with the original code.

No more changes to golang.org/x/tools please. This should not have
happened (and letting it happen was partly my fault).

Change-Id: Ia879ea1d15d82372df14853f919263125dfb7b96
Reviewed-on: https://go-review.googlesource.com/14821Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The code assumed that if the first entry was unexported, all the
entries were. The fix is simple: delete a bunch of code.

Fixes #12286.

Change-Id: Icb09274e99ce97df4d8bddbe59d17a5c0622e4c6
Reviewed-on: https://go-review.googlesource.com/14780Reviewed-by: Andrew Gerrand <adg@golang.org>

The fields step and redoState of struct scanner are now defined as
`func(s *scanner, c byte) int` instead of
`func(s *scanner, c int) int`, since bytes are sufficient.
Further changes improve the consistency in the scanner.go file.

Change-Id: Ifb85f2130d728d2b936d79914d87a1f0b5c6ee7d
Reviewed-on: https://go-review.googlesource.com/14801Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Andrew Gerrand <adg@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Passes go build -a -toolexec 'toolstash -cmp' std cmd.

Change-Id: I2a87d31da74affdf3d0f358d0efdb3f1c646d917
Reviewed-on: https://go-review.googlesource.com/14759Reviewed-by: Dave Cheney <dave@cheney.net>

I was being too clever, as usual. Write the obvious code to make sure
that when we grow the buffer we don't overflow.

Change-Id: I1641831177b0bb8a89ab6e9bcabccf6c2fcfe1d2
Reviewed-on: https://go-review.googlesource.com/14781Reviewed-by: Minux Ma <minux@golang.org>

In the present code, there is no way for ok to ever return false, but
it still a good idea to check it.

Change-Id: I8f360018b33a5d85dabbbbec0f89ffc81f77ecbb
Reviewed-on: https://go-review.googlesource.com/13956Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Sometimes this read is instrumented by compiler when it creates
a temp to take address, but sometimes it is not (e.g. for global vars
compiler takes address of the global directly).

Instrument convT2E/I similarly to chansend and mapaccess.

Fixes #12664

Change-Id: Ia7807f15d735483996426c5f3aed60a33b279579
Reviewed-on: https://go-review.googlesource.com/14752Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Temporary fix to get the arm5 builder happy again.

Without hardware floating point, this test takes over 20 minutes to
run.

A proper solution would probably be to run all the benchmark tests,
but with a much lower iteration count, just to exercise the code.

Updates golang/go#12688

Change-Id: Ie56c93d3bf2a5a693a33217ba1b1df3c6c856442
Reviewed-on: https://go-review.googlesource.com/14775Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Minux Ma <minux@golang.org>

intLiteral is used by the gins wrappers in arm64, ppc64 and
mips64. Refactor the function to a method on gc.Node and update
the callers to use the common copy.

Change-Id: I2db90d801a9cb18f8526eb921e13daa75ca1cf6f
Reviewed-on: https://go-review.googlesource.com/14744Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
Reviewed-by: Dave Cheney <dave@cheney.net>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This test fails on arm64 and some amd64 OSs and fails on Linux/amd64
if you remove the first runtime.GC(), which should be unnecessary, and
run it in all.bash (but not if you run it in isolation). I don't
understand any of these failures, so for now just remove this test.

TBR=rlh

Change-Id: Ibed00671126000ed7dc5b5d4af1f86fe4a1e30e1
Reviewed-on: https://go-review.googlesource.com/14767Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently when the GC prints an object for debugging (e.g., for a
failed invalidptr or checkmark check), it dumps the entire object. To
avoid inundating the user with output for really large objects, limit
this to printing just the first 128 words (which are most likely to be
useful in identifying the type of an object) and the 32 words around
the problematic field.

Change-Id: Id94a5c9d8162f8bd9b2a63bf0b1bfb0adde83c68
Reviewed-on: https://go-review.googlesource.com/14764Reviewed-by: Rick Hudson <rlh@golang.org>

By default, the runtime panics if it detects a pointer to an
unallocated span. At this point, this usually catches bad uses of
unsafe or cgo in user code (though it could also catch runtime bugs).
Unfortunately, the rather cryptic error misleads users, offers users
little help with debugging their own problem, and offers the Go
developers little help with root-causing.

Improve the error message in various ways. First, the wording is
improved to make it clearer what condition was detected and to suggest
that this may be the result of incorrect use of unsafe or cgo. Second,
we add a dump of the object containing the bad pointer so that there's
at least some hope of figuring out why a bad pointer was stored in the
Go heap.

Change-Id: I57b91b12bc3cb04476399d7706679e096ce594b9
Reviewed-on: https://go-review.googlesource.com/14763Reviewed-by: Rick Hudson <rlh@golang.org>

Change-Id: I9bd5c1b66fd90f0b54bd1a8f3e57b6830d2b7733
Reviewed-on: https://go-review.googlesource.com/13846Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: Iaa01d34caf09c12c017dc0379d4fe1d2cffd5340
Reviewed-on: https://go-review.googlesource.com/14728Reviewed-by: Rob Pike <r@golang.org>

Add Scanner.Buffer, which lets the user give a buffer to
the scanner and set the maximum token size.

We call it Buffer not SetBuffer for consistency with Split, which
perhaps should have been called SetSplit; too late regardless.

Both Buffer and Split panic if they are called after Scan. The
panic in Split is new, but the comment on the method already
said it needed to be called first, so we might as well add the
verification while we're doing it for Buffer.

This method allows precise user control of storage.

Fixes #11702.

Change-Id: I80e3d0e3830562fdabd4f7b08f322e1378248c39
Reviewed-on: https://go-review.googlesource.com/14599Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: roger peppe <rogpeppe@gmail.com>

Instead of a 10 second test unit, make it 13 sub-second ones. This
takes advantage of multiple builders better.

Fixes #12623

Change-Id: I3fb2eb02f899f25749e34b546b9d41b742a746cd
Reviewed-on: https://go-review.googlesource.com/14738Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Add some error catches to prevent looping at EOF.
Also give better diagnostics.
Also add tests for these cases.

Fixes #12656.

Change-Id: I1355fc149b71c868e740bfa53de29c25d160777d
Reviewed-on: https://go-review.googlesource.com/14710Reviewed-by: Andrew Gerrand <adg@golang.org>

On amd64, the program

TEXT    foo0(SB),7,$-8
    ADDQ R520, R1
    RET

used to trigger this error because R520 was being passed through to obj:

asm: doasm: notfound ft=23 tt=23 00000 (x.s:2)	ADDQ	0, 0 23 23

Now it gets this one, as it is indeed a parse error:

x.s:2: illegal addressing mode for symbol R520

This couldn't be fixed until #12632 had been fixed for arm64.

Fixes #12470.

Change-Id: I19830c4ae9337887b93f85d9a239e2b89dbb2219
Reviewed-on: https://go-review.googlesource.com/14691Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>

Fixes #12667.

Change-Id: I68e73e26da9938606304163ae2637e3c6bacd6f6
Reviewed-on: https://go-review.googlesource.com/14722Reviewed-by: Alan Donovan <adonovan@google.com>

- simpler code
- closer to gc error messages
- more context information in some cases

Change-Id: Iad155a887b838a4fc1edf719eed18269670b5ede
Reviewed-on: https://go-review.googlesource.com/14720Reviewed-by: Alan Donovan <adonovan@google.com>

- more uniform error messages
- removed unused code

Change-Id: I625d5c2e51a543450ad091f97cec538023ddb1dd
Reviewed-on: https://go-review.googlesource.com/14692Reviewed-by: Alan Donovan <adonovan@google.com>

Also: Added initial set of (missing and/or spread out) tests for binary operations.

Fixes #11896.

Change-Id: I037436d8318c18f9758b435eca2d45b3bdd17ef8
Reviewed-on: https://go-review.googlesource.com/14660Reviewed-by: Alan Donovan <adonovan@google.com>

Change-Id: I101e9bc722f5ba4fa9941cb544d9c276fd4c0b8c
Reviewed-on: https://go-review.googlesource.com/14651Reviewed-by: Alan Donovan <adonovan@google.com>

Fixes #10260.

Change-Id: I52d059144608912e6f7f9516e4961a75e9463355
Reviewed-on: https://go-review.googlesource.com/14644Reviewed-by: Alan Donovan <adonovan@google.com>

This one of a set of changes to make the transition away from NodeList
easier by removing cases in which NodeList doesn't act semi-trivially like a
[]*Node.

This CL was originally prepared by Josh Bleecher Snyder <josharian@gmail.com>.

This change passes go build -toolexec 'toolstash -cmp' -a std.

Change-Id: Ifd73501e06e8ea5efd028b6d473b3e5d1b07a5ac
Reviewed-on: https://go-review.googlesource.com/14570Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

cmd/dist needs to re-exec or open itself to detect GOARM (CL 3973) and
detect host machine endianness (CL 14460).

Change-Id: If6438831ab0715ba8e236d64bb2c7c1bde1470aa
Reviewed-on: https://go-review.googlesource.com/14476Reviewed-by: Ian Lance Taylor <iant@golang.org>

Passes go build -a -toolexec 'toolstash -cmp' std cmp.

Change-Id: I7567355d405c976c5d91a0cd4e9486ebeb348dbb
Reviewed-on: https://go-review.googlesource.com/14682Reviewed-by: Dave Cheney <dave@cheney.net>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

A followup CL will rewrite listsort to use the new cmpstackvarlt and
change cmpstackvar to avoid stringsCompare.

Change-Id: Idf0857a3bd67f9e2243ba82aa0bff510612927c3
Reviewed-on: https://go-review.googlesource.com/14611Reviewed-by: Dave Cheney <dave@cheney.net>

Made use of range statement in for loops.
Cleaning along the way:
-remove unnecessary variable declarations
-rename variables
-remove dead code

This change passes go build -toolexec 'toolstash -cmp' -a std.

Change-Id: Ife8c2a98482a81ba91f5bbb65142d9f3dc46d6ee
Reviewed-on: https://go-review.googlesource.com/14379
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>

The definition of 'truth' used by if etc. is not trivial to compute, so publish
the implementation to allow custom template functions to have the
same definition as the template language itself.

Fixes #12033.

Change-Id: Icdfd6039722d7d3f984ba0905105eb3253e14831
Reviewed-on: https://go-review.googlesource.com/14593Reviewed-by: Andrew Gerrand <adg@golang.org>

This is understood, obvious (to me), and well known but has not been clearly documented.

Fixes #11117.

Change-Id: Ib2b1e318924748d1eac0d735ad6286533be7fd39
Reviewed-on: https://go-review.googlesource.com/14693Reviewed-by: Ian Lance Taylor <iant@golang.org>