Change-Id: Ia817e78d9678a365a76fea5e4dbe8f8a5aab0bac
Reviewed-on: https://go-review.googlesource.com/7143Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: Ibda6a5bedaff57fd161d63fc04ad260931d34413
Reviewed-on: https://go-review.googlesource.com/7142Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I92b4301b64054272d78dd15c16bf6ff592acad26
Reviewed-on: https://go-review.googlesource.com/7141Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: Ia6c3d5e7a32b20e3c45d9485e66b48cd02644280
Reviewed-on: https://go-review.googlesource.com/7140Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Russ Cox <rsc@golang.org>

No peep optimizer yet.

Change-Id: Ifa5f993cd6ac5e34783c0df41faf772fbce96ae2
Reviewed-on: https://go-review.googlesource.com/7049Reviewed-by: Russ Cox <rsc@golang.org>

Only internal linking without cgo is supported for now.

Change-Id: I91eb1572c1ccc805db62fc4c29080df98797d51a
Reviewed-on: https://go-review.googlesource.com/7048Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Pre/post-index addressing modes with writeback use .W and .P
instruction suffixes, like on ARM.

Complex addressing modes are not supported yet.

Change-Id: I537a1c3fe5b057c0812662677d0010bc8c468ffb
Reviewed-on: https://go-review.googlesource.com/7047Reviewed-by: Rob Pike <r@golang.org>

ARM64 (ARMv8) has 32 general purpose, 64-bit integer registers
(R0-R31), 32 64-bit scalar floating point registers (F0-F31), and
32 128-bit vector registers (unused, V0-V31).

R31 is either the stack pointer (RSP), or the zero register (ZR),
depending on the instruction. Note the distinction between the
hardware stack pointer, RSP, and the virtual stack pointer SP.

The (hardware) stack pointer must be 16-byte aligned at all times;
the RSP register itself must be aligned, offset(RSP) only has to
have natural alignment.

Instructions are fixed-width, and are 32-bit wide. ARM64 supports
ARMv7 too (32-bit ARM), but not in the same process. In general,
there is not much in common between 32-bit ARM and ARM64, it's a
new architecture.

All implementations have floating point instructions.

This change adds a Prog.To3 field analogous to Prog.To. It is used
by exclusive load/store instructions such as STLXR which read from
one register, and write to both a register and a memory address.

	STLXRW	R1, (R0), R3

This will store the word contained in R1 to the memory address
pointed by R0. R3 will be updated with the status result of the
store. It is used to implement atomic operations.

No other changes are made to the portable Prog and Addr structures.

Change-Id: Ie839029aa5265bbad35769d9689eca11e1c48c47
Reviewed-on: https://go-review.googlesource.com/7046Reviewed-by: Russ Cox <rsc@golang.org>

ARM64 doesn't have the old assembler.

Change-Id: I9253271029440e2b7f2813d3e98a7d2e7a65bfbc
Reviewed-on: https://go-review.googlesource.com/7045Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I51db032e3dc2762d94e4000914b30813946250f7
Reviewed-on: https://go-review.googlesource.com/7044Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

Change-Id: I56297aac4ee282fd117ec525b88dee4769477111
Reviewed-on: https://go-review.googlesource.com/7560Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

Change-Id: I7bac7b659b7ff425c6f896c286d0f89f05eff6bd
Reviewed-on: https://go-review.googlesource.com/7601Reviewed-by: Minux Ma <minux@golang.org>

Change-Id: I45383de6d627be35f40e07a9008b6773f5c2b0d0
Reviewed-on: https://go-review.googlesource.com/7613Reviewed-by: Minux Ma <minux@golang.org>

OpenBSD/arm only currently supports softfloat, hence make the default GOARM=5.

Change-Id: Ie3e8f457f001b3803d17ad9bc4ab957b2da18c6a
Reviewed-on: https://go-review.googlesource.com/7614Reviewed-by: Minux Ma <minux@golang.org>

Change-Id: I9fe15781f52e0d16707a9c021cf800319721a606
Reviewed-on: https://go-review.googlesource.com/4913Reviewed-by: Minux Ma <minux@golang.org>

Change-Id: I2bc101aa19172e705ee4de5f3c73a8b4bbf4fa6f
Reviewed-on: https://go-review.googlesource.com/4912Reviewed-by: Minux Ma <minux@golang.org>

Change-Id: Ibb7e4f6b95b7a9782a47221cafbe4f20dd77fd38
Reviewed-on: https://go-review.googlesource.com/7583Reviewed-by: Minux Ma <minux@golang.org>

Fixes #10167.

Change-Id: Ib6c6b2b5dde47744b69f65482a21964fa3c12090
Reviewed-on: https://go-review.googlesource.com/7600Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

DragonFlyBSD dropped support for i386 in 4.0 and there is no longer a
dragonfly/386 - as such, remove the Go port.

Fixes #8951
Fixes #7580
Fixes #7421

Change-Id: I69022ab2262132e8f97153f14dc8c37c98527008
Reviewed-on: https://go-review.googlesource.com/7543Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Joel Sing <jsing@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I91f9b5280e08e005f5a891aaa249267c211d814b
Reviewed-on: https://go-review.googlesource.com/7592Reviewed-by: Minux Ma <minux@golang.org>

Fixes #10118.

Change-Id: I4a2e6748db609c6eed1d68c824b81c59bd7b875c
Reviewed-on: https://go-review.googlesource.com/7590Reviewed-by: Minux Ma <minux@golang.org>

Change-Id: Ieb13359c5bbe26bbf7baaaa8eb63d5e90bdefdd8
Reviewed-on: https://go-review.googlesource.com/7591Reviewed-by: Minux Ma <minux@golang.org>

Just little bits and pieces I noticed were unused in passing, and
some more found with https://github.com/opennota/check.

Change-Id: I199fecdbf8dc2ff9076cf4ea81395275c7f171c3
Reviewed-on: https://go-review.googlesource.com/7033Reviewed-by: Minux Ma <minux@golang.org>
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: I3096a7497955bc475739739ee23be387e9162867
Reviewed-on: https://go-review.googlesource.com/7210
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Float.Cmp used to return a value < 0, 0, or > 0 depending on how
arguments x, y compared against each other. With the possibility
of NaNs, the result was changed into an Accuracy (to include Undef).
Consequently, Float.Cmp results could still be compared for (in-)
equality with 0, but comparing if < 0 or > 0 would provide the
wrong answer w/o any obvious notice by the compiler.

This change wraps Float.Cmp results into a struct and accessors
are used to access the desired result. This prevents incorrect
use.

Change-Id: I34e6a6c1859251ec99b5cf953e82542025ace56f
Reviewed-on: https://go-review.googlesource.com/7526Reviewed-by: Rob Pike <r@golang.org>

Fixes #10068.

Change-Id: I1f12225ee16b0090b87403931c0bc0157f068309
Reviewed-on: https://go-review.googlesource.com/6555Reviewed-by: Minux Ma <minux@golang.org>

namebuf was a global char buffer in the C version of gc, which was
useful for providing common storage for constructing symbol and file
names.  However, now that it's just a global Go string and the string
data is dynamically allocated anyway, it doesn't serve any purpose
except to force extra write barriers everytime it's assigned to.

Also, introduce Lookupf(fmt, args...) as shorthand for
Lookup(fmt.Sprintf(fmt, args...)), which was a very common pattern for
using namebuf.

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

Notably, this CL shrinks 6g's text section by ~15kB:

$ size toolstash/6g tool/linux_amd64/6g
   text	   data	    bss	    dec	    hex	filename
4600805	 605968	 342988	5549761	 54aec1	toolstash/6g
4585547	 605968	 342956	5534471	 547307	tool/linux_amd64/6g

Change-Id: I98abb44fc7f43a2e2e48425cc9f215cd0be37442
Reviewed-on: https://go-review.googlesource.com/7080Reviewed-by: Ian Lance Taylor <iant@golang.org>

Update cmd/7g to match the other compilers. Fixes build break in rev 6582d1cf.

Change-Id: I449613cf348254e9de6cc7a6b7737e43ea7d10fe
Reviewed-on: https://go-review.googlesource.com/7580Reviewed-by: Dave Cheney <dave@cheney.net>

The argument is never consulted apart from passing it to recursive
calls.  So delete it.

Change-Id: Ia15eefb6385b3c99ea4def88f564f4e5a94c68ab
Reviewed-on: https://go-review.googlesource.com/7032Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I9ea6d4d8a9c1c63de36f2f3871dd5ac9201c0aac
Reviewed-on: https://go-review.googlesource.com/7523Reviewed-by: Minux Ma <minux@golang.org>

Change-Id: Ib42f75c03573cec16801b79a6eb9b1b542028f4f
Reviewed-on: https://go-review.googlesource.com/7524Reviewed-by: Alan Donovan <adonovan@google.com>

Change-Id: If335d45ea1ab6c8aeeb47515f97680e2c1d651f3
Reviewed-on: https://go-review.googlesource.com/7522Reviewed-by: Alan Donovan <adonovan@google.com>

Fixes #10154

Change-Id: Ibb8ea9bcf512e7639c57a6f17afbe4495fa329cd
Reviewed-on: https://go-review.googlesource.com/7494Reviewed-by: Minux Ma <minux@golang.org>

The kern.rthreads sysctl has not existed for a long time - there is no way to
disable rthreads and __tfork no longer returns ENOTSUP.

Change-Id: Ia50ff01ac86ea83358e72b8f45f7818aaec1e4b1
Reviewed-on: https://go-review.googlesource.com/7490Reviewed-by: Minux Ma <minux@golang.org>

Change-Id: If58ea50fbf321ae943d0890a40e0552e7bc19709
Reviewed-on: https://go-review.googlesource.com/2080Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I9f5ca101e0d2fe71cb1ca810cfeeb82c12f5f8e7
Reviewed-on: https://go-review.googlesource.com/7491Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: I0a8b972c33e80c750ff1d63717177a5a3294a112
Reviewed-on: https://go-review.googlesource.com/7445Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Geert-Johan Riemer <gjr19912@gmail.com>
Reviewed-by: Andrew Gerrand <adg@golang.org>

Also:
- Implemented NewFloat convenience factory function (analogous to
  NewInt and NewRat).
- Implemented convenience accessors for Accuracy values returned
  from Float.Cmp.
- Added test and example.

Change-Id: I985bb4f86e6def222d4b2505417250d29a39c60e
Reviewed-on: https://go-review.googlesource.com/6970Reviewed-by: Alan Donovan <adonovan@google.com>

Four spaces is what works well for both 4- and 8-space tab stops.

Screen with fixed-width font and 4-space tab stops:
http://imgur.com/lps5Lbb

Change-Id: I7d2b813d674c3e0a68f79d63bc5d5ec5bd4f87bb
Reviewed-on: https://go-review.googlesource.com/7503Reviewed-by: Rob Pike <r@golang.org>

This is a fairly significant _internal_ representation change. Instead
of encoding 0, finite, infinite, and NaN values with special mantissa
and exponent values, a new (1 byte) 'form' field is used (without making
the Float struct bigger). The form field permits simpler and faster
case distinctions. As a side benefit, for zero and non-finite floats,
fewer fields need to be set. Also, the exponent range is not the full
int32 range (in the old format, infExp and nanExp were used to represent
Inf and NaN values and tests for those values sometimes didn't test
for the empty mantissa, so the range was reduced by 2 values).

The correspondence between the old and new fields is as follows.
Old representation:

x                 neg      mant         exp
---------------------------------------------------------------
+/-0              sign     empty        0
0 < |x| < +Inf    sign     mantissa     exponent
+/-Inf            sign     empty        infExp
NaN               false    empty        nanExp

New representation (- stands for ignored fields):

x                 neg      mant         exp         form
---------------------------------------------------------------
+/-0              sign     -            -           zero
0 < |x| < +Inf    sign     mantissa     exponent    finite
+/-Inf            sign     -            -           inf
NaN               -        -            -           nan

Client should not be affected by this change.

Change-Id: I7e355894d602ceb23f9ec01da755fe6e0386b101
Reviewed-on: https://go-review.googlesource.com/6870Reviewed-by: Alan Donovan <adonovan@google.com>