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Author SHA1 Message Date
Péter Surányi
9b6ccb1323 all: don't refer to code.google.com/p/go{,-wiki}/
Only documentation / comment changes. Update references to
point to golang.org permalinks or go.googlesource.com/go.
References in historical release notes under doc are left as is.

Change-Id: Icfc14e4998723e2c2d48f9877a91c5abef6794ea
Reviewed-on: https://go-review.googlesource.com/4060
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-02-06 14:41:47 +00:00
Shenghou Ma
3d1ccf8964 cmd/dist, make.bash: darwin/arm support
cmd/dist: recognize darwin/arm as (host) goos/goarches. also hard
          code GOARM=7 for darwin/arm.
make.bash: don't pass -mmacosx-version-min=10.6 when building for
           darwin/arm.

Change-Id: If0ecd84a5179cd9bb61b801ac1899adc45f12f75
Reviewed-on: https://go-review.googlesource.com/2126
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-02-06 05:49:58 +00:00
Shenghou Ma
1083715b7f liblink, cmd/ld, cmd/5l: darwin/arm support
liblink:
 - set dummy value for ctxt->tlsoffset.
cmd/ld:
 - always do external linking when using cgo on darwin/arm,
   as our linker might not generate codesign-compatible binary.
cmd/5l:
 - support generate ARM Mach-O binaries
 - add machoreloc1() that translate our internal relocation to
   macho relocations used by external linking.

Change-Id: Ic5454aeb87009aaf8f1453ec7fe33e6da55d5f06
Reviewed-on: https://go-review.googlesource.com/3273
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-02-06 05:41:15 +00:00
Shenghou Ma
d738c6b0ca liblink, cmd/ld, runtime: set the type of runtime.tlsg in runtime
In the old code, liblink, cmd/ld and runtime all have code determine
whether runtime.tlsg is an actual variable or a placeholder for TLS
relocation. This change consolidate them into one: the runtime/tls_arm.s
will ultimately determine the type of that variable.

Change-Id: I3b3f80791a1db4c2b7318f81a115972cd2237e43
Reviewed-on: https://go-review.googlesource.com/2118
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
2015-02-06 05:39:51 +00:00
Shenghou Ma
3819907a55 cmd/cgo: detect misuse of generated _cgo_export.h
Fixes #9742.

Change-Id: Ifedf7ff9465bc49534b708d414c8e435ee9ce6cd
Reviewed-on: https://go-review.googlesource.com/3970
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-02-06 05:37:02 +00:00
Russ Cox
7e3b30aea6 cmd/5a: prepare reglist correctly
This was working when 5a was built on x86 because REG_R0 = 32,
and a 32-bit shift on x86 uses only the low 32 bits of the shift count.

On ARM, the shift clamping is different.

Moving to Go will avoid these differing shift semantics.
I tripped over and fixed this bug in new5a the same way earlier tonight.

Change-Id: Id56aa0bb1830ccf250960f843e0acb8a0409e87d
Reviewed-on: https://go-review.googlesource.com/3961
Reviewed-by: Dave Cheney <dave@cheney.net>
2015-02-05 16:05:13 +00:00
Russ Cox
cb4b28e013 Revert "liblink, cmd/5a: fix reglist parsing/printing after changing REG_R0 to 32"
This reverts commit da4abda2a1.

Change-Id: Ifd09b3dae0af0c7cef5fbbc332c63e78dc90d6b1
Reviewed-on: https://go-review.googlesource.com/3960
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-05 10:23:35 +00:00
Shenghou Ma
98376204e8 cmd/ld: always set timestamp in PE header to 0
Fixes #9756.

Change-Id: If4ee6fe10f8f90294ff9c5e7480371494094b111
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/3740
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2015-02-05 02:45:03 +00:00
Shenghou Ma
da4abda2a1 liblink, cmd/5a: fix reglist parsing/printing after changing REG_R0 to 32
Fixes #9759.

Change-Id: I263f1251b9401371231374551c4f71c70cb6e359
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/3931
Reviewed-by: Dave Cheney <dave@cheney.net>
2015-02-05 02:40:09 +00:00
Rob Pike
706cc13b21 cmd/pack: simplify the testing logic slightly
Followup to https://go-review.googlesource.com/3910

We only need 1000 iteratinons.

Change-Id: Ib63ae53105176abec77bad9609d638aeda7bcd61
Reviewed-on: https://go-review.googlesource.com/3901
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-02-05 00:28:00 +00:00
Russ Cox
1f2d7bf44f liblink: require use of TYPE_ADDR, not TYPE_CONST
Add Addr-checking for all Progs on input to liblink, in liblink/pass.c,
including requiring use of TYPE_ADDR, not TYPE_CONST.
Update compilers and assemblers to satisfy checks.

Change-Id: Idac36b9f6805f0451cb541d2338992ca5eaf3963
Reviewed-on: https://go-review.googlesource.com/3801
Reviewed-by: Austin Clements <austin@google.com>
2015-02-04 16:50:06 +00:00
Josh Bleecher Snyder
22f337656d cmd/go, make: remove ccflags
cc is no more.

Change-Id: I8d1bc0d2e471cd9357274204c9bc1fa67cbc272d
Reviewed-on: https://go-review.googlesource.com/3833
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2015-02-04 16:15:00 +00:00
Josh Bleecher Snyder
3fa90ea964 cmd/go: add 9g and 9l to documentation
Change-Id: I274c438ab168278dfbb34ada3ed9a7f7c66b66ef
Reviewed-on: https://go-review.googlesource.com/3834
Reviewed-by: Minux Ma <minux@golang.org>
2015-02-04 16:10:28 +00:00
Dmitry Vyukov
71be013842 cmd/gc: don't copy string in range []byte(str)
Using benchmark from the issue:

benchmark                    old ns/op     new ns/op     delta
BenchmarkRangeStringCast     2162          1152          -46.72%

benchmark                    old allocs     new allocs     delta
BenchmarkRangeStringCast     1              0              -100.00%

Fixes #2204

Change-Id: I92c5edd2adca4a7b6fba00713a581bf49dc59afe
Reviewed-on: https://go-review.googlesource.com/3790
Reviewed-by: Keith Randall <khr@golang.org>
2015-02-04 04:37:21 +00:00
Josh Bleecher Snyder
16e933c266 cmd/dist: fix whitespace and comment typo in arm vfp detection
Follow-up to cl 2682.

Change-Id: I06a589e782af821e4fa46a7c34d9a549de47fa60
Reviewed-on: https://go-review.googlesource.com/3830
Reviewed-by: Dave Cheney <dave@cheney.net>
2015-02-04 00:04:09 +00:00
Russ Cox
2e5b065ac2 liblink: define fixed A-numbers for common instructions
This makes names like ANOP, ATEXT, AGLOBL, ACALL, AJMP, ARET
available for use by architecture-independent processing passes.

On arm and ppc64, the alternate names are now aliases for the
official ones (ABL for ACALL, AB or ABR for AJMP, ARETURN for ARET).

Change-Id: Id027771243795af2b3745199c645b6e1bedd7d18
Reviewed-on: https://go-review.googlesource.com/3577
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
Reviewed-by: Austin Clements <austin@google.com>
2015-02-03 18:23:05 +00:00
Russ Cox
3ac37c72ae liblink: place DATA size in from3.offset always
Like the TEXT/GLOBL flags, this was split between from.scale and reg,
neither of which is appropriate.

Change-Id: I2a16ef066a53b6edb7afb16cce108c0d1d26389c
Reviewed-on: https://go-review.googlesource.com/3576
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
Reviewed-by: Austin Clements <austin@google.com>
2015-02-03 18:22:57 +00:00
Russ Cox
76fed5426c liblink: the zero Prog is now valid and ready for use
Use AXXX instead of AGOK (neither is a valid instruction but AXXX is zero)
for the initial setting of Prog.as, and now there are no non-zero default
field settings.

Remove the arch-specific zprog/zprg in favor of a single global zprog.
Remove the arch-specific prg constructor in favor of emallocz(sizeof(Prog)).

Change-Id: Ia73078726768333d7cdba296f548170c1bea9498
Reviewed-on: https://go-review.googlesource.com/3575
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
Reviewed-by: Austin Clements <austin@google.com>
2015-02-03 18:22:45 +00:00
Russ Cox
e66ad16ddb liblink: renumber ARM conditions to make C_SCOND_NONE == 0
A step toward making the zero Prog useful.

Change-Id: I427b98b1ce9bd8f093da825aa4bb83244fc01903
Reviewed-on: https://go-review.googlesource.com/3573
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Austin Clements <austin@google.com>
2015-02-03 18:22:26 +00:00
Russ Cox
77a415e5a6 liblink: place TEXT/GLOBL flags in p->from3 always
Before, amd64 and 386 stored the flags in p->from.scale
and arm and ppc64 stored the flags in p->reg.
Both caused special cases in printing and in handling of the
addresses.

To avoid possible conflicts with the real meaning of p->from
and to avoid storing a non-register value in a reg field,
use from3 to hold a TYPE_CONST value giving the flags.

There is still a special case for printing, because the flags
are specified without a $, and normally a TYPE_CONST prints
with a $. But that's much less special than what came before.

This allows us to remove the textflag and settextflag methods
from LinkArch. They are no longer architecture-specific.

Change-Id: I931da8e1ecd92e127cd9aa44ef5a73c42e730110
Reviewed-on: https://go-review.googlesource.com/3572
Reviewed-by: Austin Clements <austin@google.com>
2015-02-03 18:22:15 +00:00
Russ Cox
72521319c7 liblink: use same TEXT $frame-arg encoding for all architectures
Change-Id: I3417a8c5ddd7f405939edc9fdef086e4741495a1
Reviewed-on: https://go-review.googlesource.com/3571
Reviewed-by: Austin Clements <austin@google.com>
2015-02-03 18:22:07 +00:00
Russ Cox
a293c7e68f cmd/9a: fix GLOBL instruction
Because it was lumped in with the TEXT instruction,
the high 32 bits of the 64-bit constant holding the size
were always set to 0x80000000 (ArgsSizeUnknown).
This only worked because cmd/9l was reading the 64-bit
value into an int32.

While we're here, fix 5a.
It wasn't as much of a problem there because
the two values were being stored in two different fields.
But it was still wrong.

Change-Id: I69a2214c7be939530d499e29cfdc3b26720ac05a
Reviewed-on: https://go-review.googlesource.com/3570
Reviewed-by: Austin Clements <austin@google.com>
2015-02-03 18:21:54 +00:00
Dmitry Vyukov
eaa872009d cmd/gc: fix capturing by value for range statements
Kindly detected by race builders by failing TestRaceRange.
ORANGE typecheck does not increment decldepth around body.

Change-Id: I0df5f310cb3370a904c94d9647a9cf0f15729075
Reviewed-on: https://go-review.googlesource.com/3507
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-03 15:48:48 +00:00
Dmitry Vyukov
8e2423a67d cmd/gc: typecheck type switch variables
Type switch variables was not typechecked.
Previously it lead only to a minor consequence:

switch unsafe.Sizeof = x.(type) {

generated an inconsistent error message.
But capturing by value functionality now requries typechecking of all ONAMEs.

Fixes #9731

Change-Id: If037883cba53d85028fb97b1328696091b3b7ddd
Reviewed-on: https://go-review.googlesource.com/3600
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-03 15:44:06 +00:00
Austin Clements
3c0fee10db cmd/6g, liblink, runtime: support saving base pointers
This adds a "framepointer" GOEXPERIMENT that that makes the amd64
toolchain maintain base pointer chains in the same way that gcc
-fno-omit-frame-pointer does.  Go doesn't use these saved base
pointers, but this does enable external tools like Linux perf and
VTune to unwind Go stacks when collecting system-wide profiles.

This requires support in the compilers to not clobber BP, support in
liblink for generating the BP-saving function prologue and unwinding
epilogue, and support in the runtime to save BPs across preemption, to
skip saved BPs during stack unwinding and, and to adjust saved BPs
during stack moving.

As with other GOEXPERIMENTs, everything from the toolchain to the
runtime must be compiled with this experiment enabled.  To do this,
run make.bash (or all.bash) with GOEXPERIMENT=framepointer.

Change-Id: I4024853beefb9539949e5ca381adfdd9cfada544
Reviewed-on: https://go-review.googlesource.com/2992
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-02 19:36:05 +00:00
Austin Clements
36f879780a cmd/9g: note suboptimal copy code
9g generates needlessly complex code for small copies.  There are a
few other things that need to be improved about the copy code, so for
now just note the problem.

Change-Id: I0f1de4b2f9197a2635e27cc4b91ecf7a6c11f457
Reviewed-on: https://go-review.googlesource.com/3665
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-02 19:32:42 +00:00
Shenghou Ma
3bf005cea3 cmd/gc: always treat the output parameters as having been assigned in capturevars.
Fixes #9738.

Change-Id: Iab75de2d78335d4e31c3dce6a0e1826d8cddf5f3
Reviewed-on: https://go-review.googlesource.com/3690
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2015-02-02 14:14:21 +00:00
Brad Fitzpatrick
7980779374 cmd/pack: make a test less disk-intensive in short mode
Fixes #9656

Change-Id: I1158636683492ef12eeafb12e257d205026adc3f
Reviewed-on: https://go-review.googlesource.com/3175
Reviewed-by: Minux Ma <minux@golang.org>
2015-01-30 15:40:20 +00:00
Dave Cheney
ea2f3f9e7a liblink: fix arm build again
Another attempt to fix the arm build by moving the include of signal.h
to cmd/lex.c, unless we are building on plan9.

Obviously if we had a plan9/arm builder this would probably not work, but
this is only a temporary measure until the c2go transition is complete.

Change-Id: I7f8ae27349b2e7a09c55db03e02a01939159a268
Reviewed-on: https://go-review.googlesource.com/3566
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-30 14:45:37 +00:00
Russ Cox
01b6b4b43a cmd/5l, cmd/9l: more ucontext.h fixes
Change-Id: I32cad7358f5bfd8e107179653bdc55a69fbe772a
Reviewed-on: https://go-review.googlesource.com/3579
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-30 05:02:25 +00:00
Russ Cox
dc3961cfdc cmd/5l, cmd/8g: fix build failures
REG_R0 etc are defined in <ucontext.h> on ARM systems.
Possible use of uninitialized n in 8g/reg.c.

Change-Id: I6e8ce83a6515ca2b779ed8a344a25432db629cc2
Reviewed-on: https://go-review.googlesource.com/3578
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-30 04:54:37 +00:00
Russ Cox
d968bda66f cmd/dist: update for portable Prog, Addr
There are no D_ names anymore.

Change-Id: Id3f1ce5efafb93818e5fd16c47ff48bbf61b5339
Reviewed-on: https://go-review.googlesource.com/3520
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
2015-01-30 03:16:39 +00:00
Russ Cox
da47902d02 cmd/9a, cmd/9g, cmd/9l, liblink: update for portable Prog, Addr
Change-Id: I55afed0eabf3c38e72ff105294782ac36446b66b
Reviewed-on: https://go-review.googlesource.com/3519
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
2015-01-30 03:16:28 +00:00
Russ Cox
a5b1baeed7 cmd/8a, cmd/8g, cmd/8l, liblink: update for portable Prog, Addr
Change-Id: I19ed283962aa0221cf806307bde9ea0773a1bfd4
Reviewed-on: https://go-review.googlesource.com/3518
Reviewed-by: Austin Clements <austin@google.com>
2015-01-30 03:16:19 +00:00
Russ Cox
604138e87b cmd/6a, cmd/6g, cmd/6l, liblink: update for portable Prog, Addr
Change-Id: I5535582660da3504663c6cba2637da132c65a400
Reviewed-on: https://go-review.googlesource.com/3517
Reviewed-by: Austin Clements <austin@google.com>
2015-01-30 03:16:10 +00:00
Russ Cox
0d599909e9 cmd/5a, cmd/5g, cmd/5l, liblink: update for portable Prog, Addr
Change-Id: I06762d4fb3bb2616087339b6ae1eb5267a39c46a
Reviewed-on: https://go-review.googlesource.com/3516
Reviewed-by: Austin Clements <austin@google.com>
2015-01-30 03:15:58 +00:00
Russ Cox
5a2771e286 cmd/gc, cmd/ld, liblink: update for portable Prog, Addr changes
Change-Id: Ia6f8badca56565b9df80c8dbe28c47f6cf7e653f
Reviewed-on: https://go-review.googlesource.com/3515
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
2015-01-30 03:15:44 +00:00
Russ Cox
1d0664ef0d cmd/9g: use nopout in excise
In addition to duplicating the logic, the old code was
clearing the line number, which led to missing source line
information in the -S output.

Also fix nopout, which was incomplete.

Change-Id: Ic2b596a2f9ec2fe85642ebe125cca8ef38c83085
Reviewed-on: https://go-review.googlesource.com/3512
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
2015-01-30 02:49:52 +00:00
Russ Cox
83c10b204d cmd/go: add build flag -toolexec
Like the -exec flag, which specifies a program to use to run a built executable,
the -toolexec flag specifies a program to use to run a tool like 5a, 5g, or 5l.

This flag enables running the toolchain under common testing environments,
such as valgrind.

This flag also enables the use of custom testing environments or the substitution
of alternate tools. See https://godoc.org/rsc.io/toolstash for one possibility.

Change-Id: I256aa7af2d96a4bc7911dc58151cc2155dbd4121
Reviewed-on: https://go-review.googlesource.com/3351
Reviewed-by: Rob Pike <r@golang.org>
2015-01-29 16:25:53 +00:00
Dmitry Vyukov
0e80b2e082 cmd/gc: capture variables by value
Language specification says that variables are captured by reference.
And that is what gc compiler does. However, in lots of cases it is
possible to capture variables by value under the hood without
affecting visible behavior of programs. For example, consider
the following typical pattern:

	func (o *Obj) requestMany(urls []string) []Result {
		wg := new(sync.WaitGroup)
		wg.Add(len(urls))
		res := make([]Result, len(urls))
		for i := range urls {
			i := i
			go func() {
				res[i] = o.requestOne(urls[i])
				wg.Done()
			}()
		}
		wg.Wait()
		return res
	}

Currently o, wg, res, and i are captured by reference causing 3+len(urls)
allocations (e.g. PPARAM o is promoted to PPARAMREF and moved to heap).
But all of them can be captured by value without changing behavior.

This change implements simple strategy for capturing by value:
if a captured variable is not addrtaken and never assigned to,
then it is captured by value (it is effectively const).
This simple strategy turned out to be very effective:
~80% of all captures in std lib are turned into value captures.
The remaining 20% are mostly in defers and non-escaping closures,
that is, they do not cause allocations anyway.

benchmark                                    old allocs     new allocs     delta
BenchmarkCompressedZipGarbage                153            126            -17.65%
BenchmarkEncodeDigitsSpeed1e4                91             69             -24.18%
BenchmarkEncodeDigitsSpeed1e5                178            129            -27.53%
BenchmarkEncodeDigitsSpeed1e6                1510           1051           -30.40%
BenchmarkEncodeDigitsDefault1e4              100            75             -25.00%
BenchmarkEncodeDigitsDefault1e5              193            139            -27.98%
BenchmarkEncodeDigitsDefault1e6              1420           985            -30.63%
BenchmarkEncodeDigitsCompress1e4             100            75             -25.00%
BenchmarkEncodeDigitsCompress1e5             193            139            -27.98%
BenchmarkEncodeDigitsCompress1e6             1420           985            -30.63%
BenchmarkEncodeTwainSpeed1e4                 109            81             -25.69%
BenchmarkEncodeTwainSpeed1e5                 211            151            -28.44%
BenchmarkEncodeTwainSpeed1e6                 1588           1097           -30.92%
BenchmarkEncodeTwainDefault1e4               103            77             -25.24%
BenchmarkEncodeTwainDefault1e5               199            143            -28.14%
BenchmarkEncodeTwainDefault1e6               1324           917            -30.74%
BenchmarkEncodeTwainCompress1e4              103            77             -25.24%
BenchmarkEncodeTwainCompress1e5              190            137            -27.89%
BenchmarkEncodeTwainCompress1e6              1327           919            -30.75%
BenchmarkConcurrentDBExec                    16223          16220          -0.02%
BenchmarkConcurrentStmtQuery                 17687          16182          -8.51%
BenchmarkConcurrentStmtExec                  5191           5186           -0.10%
BenchmarkConcurrentTxQuery                   17665          17661          -0.02%
BenchmarkConcurrentTxExec                    15154          15150          -0.03%
BenchmarkConcurrentTxStmtQuery               17661          16157          -8.52%
BenchmarkConcurrentTxStmtExec                3677           3673           -0.11%
BenchmarkConcurrentRandom                    14000          13614          -2.76%
BenchmarkManyConcurrentQueries               25             22             -12.00%
BenchmarkDecodeComplex128Slice               318            252            -20.75%
BenchmarkDecodeFloat64Slice                  318            252            -20.75%
BenchmarkDecodeInt32Slice                    318            252            -20.75%
BenchmarkDecodeStringSlice                   2318           2252           -2.85%
BenchmarkDecode                              11             8              -27.27%
BenchmarkEncodeGray                          64             56             -12.50%
BenchmarkEncodeNRGBOpaque                    64             56             -12.50%
BenchmarkEncodeNRGBA                         67             58             -13.43%
BenchmarkEncodePaletted                      68             60             -11.76%
BenchmarkEncodeRGBOpaque                     64             56             -12.50%
BenchmarkGoLookupIP                          153            139            -9.15%
BenchmarkGoLookupIPNoSuchHost                508            466            -8.27%
BenchmarkGoLookupIPWithBrokenNameServer      245            226            -7.76%
BenchmarkClientServer                        62             59             -4.84%
BenchmarkClientServerParallel4               62             59             -4.84%
BenchmarkClientServerParallel64              62             59             -4.84%
BenchmarkClientServerParallelTLS4            79             76             -3.80%
BenchmarkClientServerParallelTLS64           112            109            -2.68%
BenchmarkCreateGoroutinesCapture             10             6              -40.00%
BenchmarkAfterFunc                           1006           1005           -0.10%

Fixes #6632.

Change-Id: I0cd51e4d356331d7f3c5f447669080cd19b0d2ca
Reviewed-on: https://go-review.googlesource.com/3166
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-29 13:07:30 +00:00
Dominik Vogt
b49c3ac2d5 cmd/cgo: add support for s390 and s390x
This patch was previously sent for review using hg:
golang.org/cl/173930043

Change-Id: I559a2f2ee07990d0c23d2580381e32f8e23077a5
Reviewed-on: https://go-review.googlesource.com/3033
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-01-29 00:51:31 +00:00
Dmitry Vyukov
4ce4d8b2c4 cmd/gc: allocate stack buffer for ORUNESTR
If result of string(i) does not escape,
allocate a [4]byte temp on stack for it.

Change-Id: If31ce9447982929d5b3b963fd0830efae4247c37
Reviewed-on: https://go-review.googlesource.com/3411
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-28 20:37:20 +00:00
Dmitry Vyukov
e6fac08146 cmd/gc: allocate buffers for non-escaped strings on stack
Currently we always allocate string buffers in heap.
For example, in the following code we allocate a temp string
just for comparison:

	if string(byteSlice) == "abc" { ... }

This change extends escape analysis to cover []byte->string
conversions and string concatenation. If the result of operations
does not escape, compiler allocates a small buffer
on stack and passes it to slicebytetostring and concatstrings.
Then runtime uses the buffer if the result fits into it.

Size of the buffer is 32 bytes. There is no fundamental theory
behind this number. Just an observation that on std lib
tests/benchmarks frequency of string allocation is inversely
proportional to string length; and there is significant number
of allocations up to length 32.

benchmark                                    old allocs     new allocs     delta
BenchmarkFprintfBytes                        2              1              -50.00%
BenchmarkDecodeComplex128Slice               318            316            -0.63%
BenchmarkDecodeFloat64Slice                  318            316            -0.63%
BenchmarkDecodeInt32Slice                    318            316            -0.63%
BenchmarkDecodeStringSlice                   2318           2316           -0.09%
BenchmarkStripTags                           11             5              -54.55%
BenchmarkDecodeGray                          111            102            -8.11%
BenchmarkDecodeNRGBAGradient                 200            188            -6.00%
BenchmarkDecodeNRGBAOpaque                   165            152            -7.88%
BenchmarkDecodePaletted                      319            309            -3.13%
BenchmarkDecodeRGB                           166            157            -5.42%
BenchmarkDecodeInterlacing                   279            268            -3.94%
BenchmarkGoLookupIP                          153            135            -11.76%
BenchmarkGoLookupIPNoSuchHost                508            466            -8.27%
BenchmarkGoLookupIPWithBrokenNameServer      245            226            -7.76%
BenchmarkClientServerParallel4               62             61             -1.61%
BenchmarkClientServerParallel64              62             61             -1.61%
BenchmarkClientServerParallelTLS4            79             78             -1.27%
BenchmarkClientServerParallelTLS64           112            111            -0.89%

benchmark                                    old ns/op      new ns/op      delta
BenchmarkFprintfBytes                        381            311            -18.37%
BenchmarkStripTags                           2615           2351           -10.10%
BenchmarkDecodeNRGBAGradient                 3715887        3635096        -2.17%
BenchmarkDecodeNRGBAOpaque                   3047645        2928644        -3.90%
BenchmarkGoLookupIP                          153            135            -11.76%
BenchmarkGoLookupIPNoSuchHost                508            466            -8.27%

Change-Id: I9ec01da816945c3329d7be3c7794b520418c3f99
Reviewed-on: https://go-review.googlesource.com/3120
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-28 20:12:38 +00:00
Dmitry Vyukov
69cd91a598 cmd/gc: don't copy []byte during string comparison
Currently we allocate a new string during []byte->string conversion
in string comparison expressions. String allocation is unnecessary in
this case, because comparison does memorize the strings for later use.
This change uses slicebytetostringtmp to construct temp string directly
from []byte buffer and passes it to runtime.eqstring.

Change-Id: If00f1faaee2076baa6f6724d245d5b5e0f59b563
Reviewed-on: https://go-review.googlesource.com/3410
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-28 19:36:50 +00:00
Dmitry Vyukov
22c16b4b92 cmd/gc: ignore re-slicing in escape analysis
Escape analysis treats everything assigned to OIND/ODOTPTR as escaping.
As the result b escapes in the following code:

	func (b *Buffer) Foo() {
		n, m := ...
		b.buf = b.buf[n:m]
	}

This change recognizes such assignments and ignores them.

Update issue #9043.
Update issue #7921.

There are two similar cases in std lib that benefit from this optimization.
First is in archive/zip:

type readBuf []byte
func (b *readBuf) uint32() uint32 {
	v := binary.LittleEndian.Uint32(*b)
	*b = (*b)[4:]
	return v
}

Second is in time:

type data struct {
	p     []byte
	error bool
}

func (d *data) read(n int) []byte {
	if len(d.p) < n {
		d.p = nil
		d.error = true
		return nil
	}
	p := d.p[0:n]
	d.p = d.p[n:]
	return p
}

benchmark                         old ns/op     new ns/op     delta
BenchmarkCompressedZipGarbage     32431724      32217851      -0.66%

benchmark                         old allocs     new allocs     delta
BenchmarkCompressedZipGarbage     153            143            -6.54%

Change-Id: Ia6cd32744e02e36d6d8c19f402f8451101711626
Reviewed-on: https://go-review.googlesource.com/3162
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-28 17:37:55 +00:00
Dmitry Vyukov
1b87f01239 cmd/gc: improve escape analysis for &T{...}
Currently all PTRLIT element initializers escape. There is no reason for that.
This change links STRUCTLIT to PTRLIT; STRUCTLIT element initializers are
already linked to the STRUCTLIT. As the result, PTRLIT element initializers
escape when PTRLIT itself escapes.

Change-Id: I89ecd8677cbf81addcfd469cd2fd461c0e9bf7dd
Reviewed-on: https://go-review.googlesource.com/3031
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-28 16:59:01 +00:00
Dmitry Vyukov
6488b217c2 cmd/go: add tracing support
cmd/go part of tracing functionality:
https://docs.google.com/document/u/1/d/1FP5apqzBgr7ahCCgFO-yoVhk4YZrNIDNf9RybngBc14/pub
Full change:
https://codereview.appspot.com/146920043

Change-Id: If346e11b8029c475b01fbf7172ce1c88171fb1b2
Reviewed-on: https://go-review.googlesource.com/1460
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-28 16:44:18 +00:00
Dmitry Vyukov
fd85a6c640 cmd/gc: fix condition for fast pathed interface conversions
For some reason the current conditions require the type to be "uintptr-shaped".
This cuts off structs and arrays with a pointer.
isdirectiface and width==widthptr is sufficient condition to enable the fast paths.

Change-Id: I11842531e7941365413606cfd6c34c202aa14786
Reviewed-on: https://go-review.googlesource.com/3414
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-28 15:33:10 +00:00
Dmitry Vyukov
b581ca5956 cmd/gc: allow map index expressions in for range statements
Fixes #9691.

Change-Id: I22bfc82e05497e91a7b18a668913aed6c723365d
Reviewed-on: https://go-review.googlesource.com/3282
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-28 15:14:04 +00:00
Dmitry Vyukov
205ae07cd3 cmd/gc: don't copy []byte during string concatenation
Consider the following code:

s := "(" + string(byteSlice) + ")"

Currently we allocate a new string during []byte->string conversion,
and pass it to concatstrings. String allocation is unnecessary in
this case, because concatstrings does memorize the strings for later use.
This change uses slicebytetostringtmp to construct temp string directly
from []byte buffer and passes it to concatstrings.

I've found few such cases in std lib:

	s += string(msg[off:off+c]) + "."
	buf.WriteString("Sec-WebSocket-Accept: " + string(c.accept) + "\r\n")
	bw.WriteString("Sec-WebSocket-Key: " + string(nonce) + "\r\n")
	err = xml.Unmarshal([]byte("<Top>"+string(data)+"</Top>"), &logStruct)
	d.err = d.syntaxError("invalid XML name: " + string(b))
	return m, ProtocolError("malformed MIME header line: " + string(kv))

But there are much more in our internal code base.

Change-Id: I42f401f317131237ddd0cb9786b0940213af16fb
Reviewed-on: https://go-review.googlesource.com/3163
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-27 18:15:42 +00:00