1
0
mirror of https://github.com/golang/go synced 2024-11-12 02:00:23 -07:00
Commit Graph

2205 Commits

Author SHA1 Message Date
Ian Lance Taylor
92e2252b21 test: don't run issue10607.go on ppc64
This is a reprise of https://golang.org/cl/12623.  In that a CL I made
a suggestion which forgot that the +build constraints in the test
directory are not the same as those supported by the go tool: in the
test directory, if a single +build line fails, the test is skipped.
(In my defense, the code I was commenting on was also wrong.)

Change-Id: I8f29392a80b1983027f9a33043c803578409d678
Reviewed-on: https://go-review.googlesource.com/12776
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-07-28 15:22:56 +00:00
Russ Cox
a2cf0568e8 Revert "test: do not run external linking test on ppc64le"
Broke most builders.

This reverts commit a60c5366f9.

Change-Id: Iae952cfcc73ef5da621616a0b3d586b60d1ce9c9
Reviewed-on: https://go-review.googlesource.com/12684
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-27 16:53:41 +00:00
Michael Hudson-Doyle
a60c5366f9 test: do not run external linking test on ppc64le
Change-Id: I9b8a6ac1ff6bef3b7f1e033bfd029f2a59e30297
Reviewed-on: https://go-review.googlesource.com/12623
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-27 16:22:12 +00:00
David Chase
731dcdae6d cmd/compile: prepend captured args to called-closure params
Old code appended, did not play well with a closure
with a ... param.

Fixes #11075.

Change-Id: Ib7c8590c5c4e576e798837e7499e00f3494efb4a
Reviewed-on: https://go-review.googlesource.com/12580
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Chase <drchase@google.com>
2015-07-23 19:02:19 +00:00
David Chase
2584974d16 cmd/compile: adjust annotation of implicit operations.
Limit probe to ODOT/OIND/ODOTPTR for now; that works.

Fixes #11790

Change-Id: I411271e702c5fe6ceb880ca47c7dacc37ffcbb6a
Reviewed-on: https://go-review.googlesource.com/12532
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-23 14:19:07 +00:00
Ian Lance Taylor
e9fcd6ed2b cmd/link: if -B option was used, pass it to the external linker
Fixes #10607.

Change-Id: Ib294cf65b07103b60f62b86b21ff2d07b25136fe
Reviewed-on: https://go-review.googlesource.com/12242
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-21 03:57:55 +00:00
Ian Lance Taylor
dabb268170 cmd/compile: ignore carriage return in magic comments
Update #11771.

Change-Id: I3bb3262619765d3ca79652817e17e8f260f41907
Reviewed-on: https://go-review.googlesource.com/12379
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-07-18 17:33:53 +00:00
Russ Cox
19916e453e test/fixedbugs: disable issue11656.go on arm64
For #11656.

Change-Id: I8365d33a15419bd0e54f71182ad0994e41650264
Reviewed-on: https://go-review.googlesource.com/12248
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-16 02:16:20 +00:00
Ian Lance Taylor
2e4b659954 cmd/compile: recognize embedded field in inlined function
There was already special code to recognize "?" in hidden_structdcl,
which is used for inlined types and variables.  This recognizes "?" in
structdcl as well, a case that arises when a struct type appears
within an inlined function body.

Fixes #10219.

Change-Id: Ic5257ae54f817e0d4a189c2294dcd633c9f2101a
Reviewed-on: https://go-review.googlesource.com/12241
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-15 06:04:51 +00:00
Russ Cox
0bcdffeea6 runtime: fix x86 stack trace for call to heap memory
Fixes #11656.

Change-Id: Ib81d583e4b004e67dc9d2f898fd798112434e7a9
Reviewed-on: https://go-review.googlesource.com/12026
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
2015-07-13 19:42:35 +00:00
Brad Fitzpatrick
2ae77376f7 all: link to https instead of http
The one in misc/makerelease/makerelease.go is particularly bad and
probably warrants rotating our keys.

I didn't update old weekly notes, and reverted some changes involving
test code for now, since we're late in the Go 1.5 freeze. Otherwise,
the rest are all auto-generated changes, and all manually reviewed.

Change-Id: Ia2753576ab5d64826a167d259f48a2f50508792d
Reviewed-on: https://go-review.googlesource.com/12048
Reviewed-by: Rob Pike <r@golang.org>
2015-07-11 14:36:33 +00:00
Russ Cox
9f90f31c3a cmd/compile: allow static init for unsafe.Pointer(&x) where x is global
This avoids both a write barrier and then dynamic initialization
globals of the form

	var x something
	var xp = unsafe.Pointer(&x)

Using static initialization avoids emitting a relocation for &x,
which helps cgo.

Fixes #9411.

Change-Id: I0dbf480859cce6ab57ab805d1b8609c45b48f156
Reviewed-on: https://go-review.googlesource.com/11693
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>
2015-07-07 21:51:57 +00:00
Russ Cox
6f80e5edf4 cmd/link: reject data size > 2 GB
We can't address more than this on amd64 anyway.

Fixes #9862.

Change-Id: Ifb1abae558e2e1ee2dc953a76995f3f08c60b1df
Reviewed-on: https://go-review.googlesource.com/11715
Reviewed-by: Austin Clements <austin@google.com>
2015-06-30 19:40:39 +00:00
Russ Cox
1122836b5f cmd/compile: reject large floating point exponents without math/big
For #11326 (but not a fix).

Change-Id: Ic51814f5cd7357427c3fd990a5522775d05e7987
Reviewed-on: https://go-review.googlesource.com/11673
Reviewed-by: Robert Griesemer <gri@golang.org>
2015-06-29 21:18:01 +00:00
Russ Cox
69f0d4c6be cmd/link: detect -X setting non-string variable
Fixes #9621.

Change-Id: Ib9c6001378364af899f57fd4b89fb23af2042923
Reviewed-on: https://go-review.googlesource.com/11694
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
2015-06-29 20:28:36 +00:00
Russ Cox
55203c7dd5 cmd/compile: allow unnamed constants to set line number
Fixes #8836.

Change-Id: Idda9f4a987e03b3bdf5e8fdb984fe56d6f84aa59
Reviewed-on: https://go-review.googlesource.com/11672
Reviewed-by: David Chase <drchase@google.com>
2015-06-29 17:35:55 +00:00
Austin Clements
840965f8d7 runtime: always clear stack barriers on G exit
Currently the runtime fails to clear a G's stack barriers in gfput if
the G's stack allocation is _FixedStack bytes. This causes the runtime
to panic if the following sequence of events happens:

1) The runtime installs stack barriers on a G.

2) The G exits by calling runtime.Goexit. Since this does not
   necessarily return through the stack barriers installed on the G,
   there may still be untriggered stack barriers left on the G's stack
   in recorded in g.stkbar.

3) The runtime calls gfput to add the exiting G to the free pool. If
   the G's stack allocation is _FixedStack bytes, we fail to clear
   g.stkbar.

4) A new G starts and allocates the G that was just added to the free
   pool.

5) The new G begins to execute and overwrites the stack slots that had
   stack barriers in them.

6) The garbage collector enters mark termination, attempts to remove
   stack barriers from the new G, and finds that they've been
   overwritten.

Fix this by clearing the stack barriers in gfput in the case where it
reuses the stack.

Fixes #11256.

Change-Id: I377c44258900e6bcc2d4b3451845814a8eeb2bcf
Reviewed-on: https://go-review.googlesource.com/11461
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-06-29 15:02:30 +00:00
Dave Cheney
834fef80ae test: add test case for issue 8154
Updates #8154

Change-Id: Ie9c731a91b008277e51c723eef6871bb0919fa4c
Reviewed-on: https://go-review.googlesource.com/10831
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-06-26 17:58:22 +00:00
Todd Neal
765c0f37ed cmd/compile: fix half multiply issue
In walkdiv, an OMUL node was created and passed to typecheck,
before the op was changed back to OHMUL.  In some instances,
the node that came back was an evaluated literal constant that
occurred with a full multiply.  The end result was a literal node
with a non-shifted value and an OHMUL op. This change causes code
to be generated for the OHMUL.

Fixes #11358
Fixes #11369

Change-Id: If42a98c6830d07fe065d5ca57717704fb8cfbd33
Reviewed-on: https://go-review.googlesource.com/11400
Reviewed-by: Russ Cox <rsc@golang.org>
2015-06-26 15:55:22 +00:00
Aaron Jacobs
8628688304 Fix several out of date references to 4g/5g/6g/8g/9g.
Change-Id: Ifb8e4e13c7778a7c0113190051415e096f5db94f
Reviewed-on: https://go-review.googlesource.com/11390
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2015-06-26 03:38:21 +00:00
Russ Cox
66130907d1 cmd/compile: handle copy in escape analysis
Somehow we missed this!
Fixes #11387.

Change-Id: Ida08fe52eff7da2ef7765b4cf35a39a301420c43
Reviewed-on: https://go-review.googlesource.com/11460
Reviewed-by: David Chase <drchase@google.com>
2015-06-24 22:22:55 +00:00
Austin Clements
a8ae93fd26 runtime: fix heap bitmap repeating with large scalar tails
When heapBitsSetType repeats a source bitmap with a scalar tail
(typ.ptrdata < typ.size), it lays out the tail upon reaching the end
of the source bitmap by simply increasing the number of bits claimed
to be in the incoming bit buffer. This causes later iterations to read
the appropriate number of zeros out of the bit buffer before starting
on the next repeat of the source bitmap.

Currently, however, later iterations of the loop continue to read bits
from the source bitmap *regardless of the number of bits currently in
the bit buffer*. The bit buffer can only hold 32 or 64 bits, so if the
scalar tail is large and the padding bits exceed the size of the bit
buffer, the read from the source bitmap on the next iteration will
shift the incoming bits into oblivion when it attempts to put them in
the bit buffer. When the buffer does eventually shift down to where
these bits were supposed to be, it will contain zeros. As a result,
words that should be marked as pointers on later repetitions are
marked as scalars, so the garbage collector does not trace them. If
this is the only reference to an object, it will be incorrectly freed.

Fix this by adding logic to drain the bit buffer down if it is large
instead of reading more bits from the source bitmap.

Fixes #11286.

Change-Id: I964432c4b9f1cec334fc8c3da0ff16460203feb6
Reviewed-on: https://go-review.googlesource.com/11360
Reviewed-by: Russ Cox <rsc@golang.org>
2015-06-23 18:37:17 +00:00
Michael Matloob
32f2f72c47 cmd/compile: provide better error when method called without receiver
When a method is called using the Type.Method(receiver, args...) syntax
without the receiver, or enough arguments, provide the more helpful
error message "not enough arguments in call to method expression
Type.Method" instead of the old message "not enough arguments in call
to Type.Method".

Fixes #8385

Change-Id: Id5037eb1ee5fa93687d4a6557b4a8233b29e9df2
Reviewed-on: https://go-review.googlesource.com/2193
Reviewed-by: Russ Cox <rsc@golang.org>
2015-06-18 19:37:38 +00:00
David Chase
5be61b18d4 cmd/compile: run escape analysis after method wrapper generation
Also modified test/run.go to ignore messages prefixed <autogenerated>
because those cannot be described with "// ERROR ...", and backed out
patch from issue #9537 because it is no longer necessary.  The reasons
described in the 9537 discussion for why escape analysis cannot run
late no longer hold, happily.

Fixes #11053.

Change-Id: Icb14eccdf2e8cde3d0f8fb8a216b765400a96385
Reviewed-on: https://go-review.googlesource.com/11088
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Chase <drchase@google.com>
2015-06-17 02:36:45 +00:00
Josh Bleecher Snyder
a44becef4a cmd/compile: use generated temps in bool codegen
Bool codegen was generating a temp for function calls
and other complex expressions, but was not using it.

This was a refactoring bug introduced by CL 7853.
The cmp code used to do (in short):

	l, r := &n1, &n2

It was changed to:

	l, r := nl, nr

But the requisite assignments:

	nl, nr = &n1, &n2

were only introduced on one of two code paths.

Fixes #10654.

Change-Id: Ie8de0b3a333842a048d4308e02911bb10c6915ce
Reviewed-on: https://go-review.googlesource.com/10844
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-06-09 17:38:26 +00:00
Josh Bleecher Snyder
494ff188f8 cmd/compile: early typecheck top level OAS2 nodes
Fixes #10977.

Change-Id: I706c953c16daad48595c7fae2d82124614dfc3ad
Reviewed-on: https://go-review.googlesource.com/10780
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
2015-06-09 00:25:02 +00:00
Shenghou Ma
21ec72c2ca test: fix build on GOARCH=ppc64/ppc64le
Change-Id: Ibf2879c0034250c5699e21ecea0eb76340597a2a
Reviewed-on: https://go-review.googlesource.com/10810
Reviewed-by: Austin Clements <austin@google.com>
2015-06-06 20:22:57 +00:00
Russ Cox
12795c02f3 cmd/link: deprecate -X name value in favor of -X name=value
People invoking the linker directly already have to change their scripts
to use the new "go tool link", so this is a good time to make the -X flag
behave like all other Go flags and take just a single argument.

The old syntax will continue to be accepted (it is rewritten into the new
syntax before flag parsing). Maybe some day we will be able to retire it.

Even if we never retire the old syntax, having the new syntax at least
makes the rewriting much less of a kludge.

Change-Id: I91e8df94f4c22b2186e81d7f1016b8767d777eac
Reviewed-on: https://go-review.googlesource.com/10310
Reviewed-by: Rob Pike <r@golang.org>
2015-06-05 04:55:41 +00:00
Brad Fitzpatrick
ec745fc4cb test: make test/run.go support sharding
Also modifies 'dist test' to use that sharding, and removes some old
temporary stuff from dist test which are no longer required.

'dist test' now also supports running a list of tests given in
arguments, mutually exclusive with the existing -run=REGEXP flag. The
hacky fast paths for avoiding the 1 second "go list" latency are now
removed and only apply to the case where partial tests are run via
args, instead of regex.  The build coordinator will use both styles
for awhile. (the statically-sharded ARM builders on scaleway will
continue to use regexps, but the dynamically-shared builders on GCE
will use the list of tests)

Updates #10029

Change-Id: I557800a54dfa6f3b5100ef4c26fe397ba5189813
Reviewed-on: https://go-review.googlesource.com/10688
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-06-04 19:45:29 +00:00
Russ Cox
73d109c509 cmd/internal/gc: accept map literals with omitted key type
Fixes #10209.

Change-Id: I248434f9195c868befd1ed8a6000a9cac72d1df8
Reviewed-on: https://go-review.googlesource.com/10263
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-04 02:31:38 +00:00
Russ Cox
fd2154f906 cmd/compile: move Node.Curfn into both Node.Func and Node.Name
$ sizeof -p cmd/compile/internal/gc Node
Node 168
$

Change-Id: If624a2d72ec04ef30a1bc7ce76c0d61a526d8a37
Reviewed-on: https://go-review.googlesource.com/10532
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-03 20:09:52 +00:00
Josh Bleecher Snyder
3ba6387bd0 test: re-enable rotate tests
Memory usage has been reduced.
The tests are still slow,
but that is issue #10571.

/usr/bin/time shows significant variation
in the peak memory usage compiling with tip.
This is unsurprising, given GC.

Using Go 1.4.2, memory is stable at 410mb.
Using tip at d2ee09298,
memory ranges from 470mb (+15%) to 534mb (+30%),
with a mean of 504mb (+23%), with n=50.

Fixes #9933.

Change-Id: Id31f3ae086ec324abf70e8f1a8044c4a0c27e274
Reviewed-on: https://go-review.googlesource.com/10211
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-05-28 19:40:58 +00:00
David Chase
596bb76248 cmd/compile: reject p-notation floats in Go source files
Use pkgimport == nil (or not) to distinguish between
parsing .go source files where "p" exponent specifier
is not allowed and parsing .a or .o export data where
it is.  Use that to control error when p-exponent is
seen.

Fixes #9036

Change-Id: I8924f09c91d4945ef3f20e80a6e544008a94a7e4
Reviewed-on: https://go-review.googlesource.com/10450
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-28 18:52:14 +00:00
Josh Bleecher Snyder
8b186df731 test: remove arch char from nosplit
This is dead code that was missed
during the 'go tool compile' migration.

Change-Id: Ice2af8a9ef72f8fd5f82225ee261854d93b659f1
Reviewed-on: https://go-review.googlesource.com/10430
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-05-28 02:30:26 +00:00
David Chase
05d8f1d166 cmd/compile: propagate correct line numbers in treecopy
Added a lineno parameter to treecopy and listtreecopy
(ignored if = 0).  When nodes are copied the copy is
assigned the non-zero lineno (normally this would be
the destination).

Fixes #8183

Change-Id: Iffb767a745093fb89aa08bf8a7692c2f0122be98
Reviewed-on: https://go-review.googlesource.com/10334
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-27 17:29:15 +00:00
David Chase
e5060c7f75 cmd/internal/gc: move check for large-hence-heap-allocated types into escape analysis
Before this change, the check for too-large arrays (and other large
types) occurred after escape analysis.  If the data moved off stack
and onto the heap contained any pointers, it would therefore escape,
but because the too-large check occurred after escape analysis this
would not be recorded and a stack pointer would leak to the heap
(see the modified escape_array.go for an example).

Some of these appear to remain, in calls to typecheck from within walk.

Also corrected a few comments in escape_array.go about "BAD"
analysis that is now done correctly.

Enhanced to move aditional EscNone-but-large-so-heap checks into esc.c.

Change-Id: I770c111baff28a9ed5f8beb601cf09dacc561b83
Reviewed-on: https://go-review.googlesource.com/10268
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-22 02:13:54 +00:00
David Chase
b19ec6842d cmd/internal/gc: make indirect calls properly escape-y
Indirect function and method calls should leak everything,
but they didn't.

This fix had no particular effect on the cost of running the
compiler on html/template/*.go and added a single new "escape"
to the standard library:

    syscall/syscall_unix.go:85: &b[0] escapes to heap
in
	if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])),
	                     uintptr(len(b))); errno != nil {

Added specific escape testing to escape_calls.go
(and verified that it fails without this patch)

I also did a little code cleanup around the changes in esc.c.

Fixes #10925

Change-Id: I9984b701621ad4c49caed35b01e359295c210033
Reviewed-on: https://go-review.googlesource.com/10295
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-22 01:36:11 +00:00
Russ Cox
cf932cd897 all: retire architecture letter in file names, public API
This CL removes the remaining visible uses of the "architecture letter" concept.
(They are no longer in tool names nor in source directory names.)

Because the architecture letter concept is now gone, delete GOCHAR
from "go env" output, and change go/build.ArchChar to return an
error always.

The architecture letter is still used in the compiler and linker sources
as a clumsy architecture enumeration, but that use is not visible to
Go users and can be cleaned up separately.

Change-Id: I4d97a38f372003fb610c9c5241bea440d9dbeb8d
Reviewed-on: https://go-review.googlesource.com/10289
Reviewed-by: Rob Pike <r@golang.org>
2015-05-21 17:32:17 +00:00
Russ Cox
0f4132c907 all: build and use go tool compile, go tool link
This CL fixes the build to use the newly created go tool compile
and go tool link in place of go tool 5g, go tool 5l, and so on.

See golang-dev thread titled "go tool compile, etc" for background.

Although it was not a primary motivation, this conversion does
reduce the wall clock time and cpu time required for make.bash
by about 10%.

Change-Id: I79cbbdb676cab029db8aeefb99a53178ff55f98d
Reviewed-on: https://go-review.googlesource.com/10288
Reviewed-by: Rob Pike <r@golang.org>
2015-05-21 17:32:03 +00:00
Russ Cox
c735064cde cmd/internal/gc: type of str[i] is byte, not uint8
Fixes #8745.

Change-Id: Id0641e3c0f259812b41ed871e83c68740feb2b19
Reviewed-on: https://go-review.googlesource.com/10261
Reviewed-by: Austin Clements <austin@google.com>
2015-05-19 19:20:25 +00:00
Russ Cox
366ba526e8 cmd/internal/gc: add missing write barrier in append(x, BigStructWithPointers)
Fixes #10897.

Change-Id: I5c2d1f9d26333e2b2a0613ebf496daa465e07c24
Reviewed-on: https://go-review.googlesource.com/10221
Reviewed-by: Austin Clements <austin@google.com>
2015-05-19 15:28:29 +00:00
David Chase
a21cf5b6a2 cmd/internal/gc: extend escape analysis to pointers in slices
Modified esc.go to allow slice literals (before append)
to be non-escaping.  Modified tests to account for changes
in escape behavior and to also test the two cases that
were previously not tested.

Also minor cleanups to debug-printing within esc.go

Allocation stats for running compiler
( cd src/html/template;
  for i in {1..5} ; do
     go tool 6g -memprofile=testzz.${i}.prof  -memprofilerate=1 *.go ;
     go tool pprof -alloc_objects -text  testzz.${i}.prof ;
     done ; )
before about 86k allocations
after  about 83k allocations

Fixes #8972

Change-Id: Ib61dd70dc74adb40d6f6fdda6eaa4bf7d83481de
Reviewed-on: https://go-review.googlesource.com/10118
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 15:34:39 +00:00
Brad Fitzpatrick
97494a45e2 Revert "cmd/internal/gc: ignore declarations of types for goto validation"
This reverts commit 5726af54eb.

It broke all the builds.

Change-Id: I4b1dde86f9433717d303c1dabd6aa1a2bf97fab2
Reviewed-on: https://go-review.googlesource.com/10143
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-05-15 16:35:49 +00:00
Daniel Morsing
5726af54eb cmd/internal/gc: ignore declarations of types for goto validation
Fixes #8042.

Change-Id: I75080f24104256065fd73b07a13c5b8e7d6da94c
Reviewed-on: https://go-review.googlesource.com/9442
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-15 16:03:47 +00:00
Russ Cox
d447279927 cmd/internal/gc: optimize slice + write barrier
The code generated for a slice x[i:j] or x[i:j:k] computes the entire
new slice (base, len, cap) and then uses it as the evaluation of the
slice expression.

If the slice is part of an update x = x[i:j] or x = x[i:j:k], there are
opportunities to avoid computing some of these fields.

For x = x[0:i], we know that only the len is changing;
base can be ignored completely, and cap can be left unmodified.

For x = x[0:i:j], we know that only len and cap are changing;
base can be ignored completely.

For x = x[i:i], we know that the resulting cap is zero, and we don't
adjust the base during a slice producing a zero-cap result,
so again base can be ignored completely.

No write to base, no write barrier.

The old slice code was trying to work at a Go syntax level, mainly
because that was how you wrote code just once instead of once
per architecture. Now the compiler is factored a bit better and we
can implement slice during code generation but still have one copy
of the code. So the new code is working at that lower level.
(It must, to update only parts of the result.)

This CL by itself:
name                   old mean              new mean              delta
BinaryTree17            5.81s × (0.98,1.03)   5.71s × (0.96,1.05)     ~    (p=0.101)
Fannkuch11              4.35s × (1.00,1.00)   4.39s × (1.00,1.00)   +0.79% (p=0.000)
FmtFprintfEmpty        86.0ns × (0.94,1.11)  82.6ns × (0.98,1.04)   -3.86% (p=0.048)
FmtFprintfString        276ns × (0.98,1.04)   273ns × (0.98,1.02)     ~    (p=0.235)
FmtFprintfInt           274ns × (0.98,1.06)   270ns × (0.99,1.01)     ~    (p=0.119)
FmtFprintfIntInt        506ns × (0.99,1.01)   475ns × (0.99,1.01)   -6.02% (p=0.000)
FmtFprintfPrefixedInt   391ns × (0.99,1.01)   393ns × (1.00,1.01)     ~    (p=0.139)
FmtFprintfFloat         566ns × (0.99,1.01)   574ns × (1.00,1.01)   +1.33% (p=0.001)
FmtManyArgs            1.91µs × (0.99,1.01)  1.87µs × (0.99,1.02)   -1.83% (p=0.000)
GobDecode              15.3ms × (0.99,1.02)  15.0ms × (0.98,1.05)   -1.84% (p=0.042)
GobEncode              11.5ms × (0.97,1.03)  11.4ms × (0.99,1.03)     ~    (p=0.152)
Gzip                    645ms × (0.99,1.01)   647ms × (0.99,1.01)     ~    (p=0.265)
Gunzip                  142ms × (1.00,1.00)   143ms × (1.00,1.01)   +0.90% (p=0.000)
HTTPClientServer       90.5µs × (0.97,1.04)  88.5µs × (0.99,1.03)   -2.27% (p=0.014)
JSONEncode             32.0ms × (0.98,1.03)  29.6ms × (0.98,1.01)   -7.51% (p=0.000)
JSONDecode              114ms × (0.99,1.01)   104ms × (1.00,1.01)   -8.60% (p=0.000)
Mandelbrot200          6.04ms × (1.00,1.01)  6.02ms × (1.00,1.00)     ~    (p=0.057)
GoParse                6.47ms × (0.97,1.05)  6.37ms × (0.97,1.04)     ~    (p=0.105)
RegexpMatchEasy0_32     171ns × (0.93,1.07)   152ns × (0.99,1.01)  -11.09% (p=0.000)
RegexpMatchEasy0_1K     550ns × (0.98,1.01)   530ns × (1.00,1.00)   -3.78% (p=0.000)
RegexpMatchEasy1_32     135ns × (0.99,1.02)   134ns × (0.99,1.01)   -1.33% (p=0.002)
RegexpMatchEasy1_1K     879ns × (1.00,1.01)   865ns × (1.00,1.00)   -1.58% (p=0.000)
RegexpMatchMedium_32    243ns × (1.00,1.00)   233ns × (1.00,1.00)   -4.30% (p=0.000)
RegexpMatchMedium_1K   70.3µs × (1.00,1.00)  69.5µs × (1.00,1.00)   -1.13% (p=0.000)
RegexpMatchHard_32     3.82µs × (1.00,1.01)  3.74µs × (1.00,1.00)   -1.95% (p=0.000)
RegexpMatchHard_1K      117µs × (1.00,1.00)   115µs × (1.00,1.00)   -1.69% (p=0.000)
Revcomp                 917ms × (0.97,1.04)   920ms × (0.97,1.04)     ~    (p=0.786)
Template                114ms × (0.99,1.01)   117ms × (0.99,1.01)   +2.58% (p=0.000)
TimeParse               622ns × (0.99,1.01)   615ns × (0.99,1.00)   -1.06% (p=0.000)
TimeFormat              665ns × (0.99,1.01)   654ns × (0.99,1.00)   -1.70% (p=0.000)

This CL and previous CL (append) combined:
name                   old mean              new mean              delta
BinaryTree17            5.68s × (0.97,1.04)   5.71s × (0.96,1.05)     ~    (p=0.638)
Fannkuch11              4.41s × (0.98,1.03)   4.39s × (1.00,1.00)     ~    (p=0.474)
FmtFprintfEmpty        92.7ns × (0.91,1.16)  82.6ns × (0.98,1.04)  -10.89% (p=0.004)
FmtFprintfString        281ns × (0.96,1.08)   273ns × (0.98,1.02)     ~    (p=0.078)
FmtFprintfInt           288ns × (0.97,1.06)   270ns × (0.99,1.01)   -6.37% (p=0.000)
FmtFprintfIntInt        493ns × (0.97,1.04)   475ns × (0.99,1.01)   -3.53% (p=0.002)
FmtFprintfPrefixedInt   423ns × (0.97,1.04)   393ns × (1.00,1.01)   -7.07% (p=0.000)
FmtFprintfFloat         598ns × (0.99,1.01)   574ns × (1.00,1.01)   -4.02% (p=0.000)
FmtManyArgs            1.89µs × (0.98,1.05)  1.87µs × (0.99,1.02)     ~    (p=0.305)
GobDecode              14.8ms × (0.98,1.03)  15.0ms × (0.98,1.05)     ~    (p=0.237)
GobEncode              12.3ms × (0.98,1.01)  11.4ms × (0.99,1.03)   -6.95% (p=0.000)
Gzip                    656ms × (0.99,1.05)   647ms × (0.99,1.01)     ~    (p=0.101)
Gunzip                  142ms × (1.00,1.00)   143ms × (1.00,1.01)   +0.58% (p=0.001)
HTTPClientServer       91.2µs × (0.97,1.04)  88.5µs × (0.99,1.03)   -3.02% (p=0.003)
JSONEncode             32.6ms × (0.97,1.08)  29.6ms × (0.98,1.01)   -9.10% (p=0.000)
JSONDecode              114ms × (0.97,1.05)   104ms × (1.00,1.01)   -8.74% (p=0.000)
Mandelbrot200          6.11ms × (0.98,1.04)  6.02ms × (1.00,1.00)     ~    (p=0.090)
GoParse                6.66ms × (0.97,1.04)  6.37ms × (0.97,1.04)   -4.41% (p=0.000)
RegexpMatchEasy0_32     159ns × (0.99,1.00)   152ns × (0.99,1.01)   -4.69% (p=0.000)
RegexpMatchEasy0_1K     538ns × (1.00,1.01)   530ns × (1.00,1.00)   -1.57% (p=0.000)
RegexpMatchEasy1_32     138ns × (1.00,1.00)   134ns × (0.99,1.01)   -2.91% (p=0.000)
RegexpMatchEasy1_1K     869ns × (0.99,1.01)   865ns × (1.00,1.00)   -0.51% (p=0.012)
RegexpMatchMedium_32    252ns × (0.99,1.01)   233ns × (1.00,1.00)   -7.85% (p=0.000)
RegexpMatchMedium_1K   72.7µs × (1.00,1.00)  69.5µs × (1.00,1.00)   -4.43% (p=0.000)
RegexpMatchHard_32     3.85µs × (1.00,1.00)  3.74µs × (1.00,1.00)   -2.74% (p=0.000)
RegexpMatchHard_1K      118µs × (1.00,1.00)   115µs × (1.00,1.00)   -2.24% (p=0.000)
Revcomp                 920ms × (0.97,1.07)   920ms × (0.97,1.04)     ~    (p=0.998)
Template                129ms × (0.98,1.03)   117ms × (0.99,1.01)   -9.79% (p=0.000)
TimeParse               619ns × (0.99,1.01)   615ns × (0.99,1.00)   -0.57% (p=0.011)
TimeFormat              661ns × (0.98,1.04)   654ns × (0.99,1.00)     ~    (p=0.223)

Change-Id: If054d81ab2c71d8d62cf54b5b1fac2af66b387fc
Reviewed-on: https://go-review.googlesource.com/9813
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-13 19:20:39 +00:00
Robert Griesemer
99475dfb59 cmd/internal/gc: avoid spurious div-zero errors
Set overflowing integer constants to 1 rather than 0 to avoid
spurious div-zero errors in subsequent constant expressions.

Also: Exclude new test case from go/types test since it's
running too long (go/types doesn't have an upper constant
size limit at the moment).

Fixes #7746.

Change-Id: I3768488ad9909a3cf995247b81ee78a8eb5a1e41
Reviewed-on: https://go-review.googlesource.com/9165
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-13 17:38:13 +00:00
Russ Cox
8552047a32 cmd/internal/gc: optimize append + write barrier
The code generated for x = append(x, v) is roughly:

	t := x
	if len(t)+1 > cap(t) {
		t = grow(t)
	}
	t[len(t)] = v
	len(t)++
	x = t

We used to generate this code as Go pseudocode during walk.
Generate it instead as actual instructions during gen.

Doing so lets us apply a few optimizations. The most important
is that when, as in the above example, the source slice and the
destination slice are the same, the code can instead do:

	t := x
	if len(t)+1 > cap(t) {
		t = grow(t)
		x = {base(t), len(t)+1, cap(t)}
	} else {
		len(x)++
	}
	t[len(t)] = v

That is, in the fast path that does not reallocate the array,
only the updated length needs to be written back to x,
not the array pointer and not the capacity. This is more like
what you'd write by hand in C. It's faster in general, since
the fast path elides two of the three stores, but it's especially
faster when the form of x is such that the base pointer write
would turn into a write barrier. No write, no barrier.

name                   old mean              new mean              delta
BinaryTree17            5.68s × (0.97,1.04)   5.81s × (0.98,1.03)   +2.35% (p=0.023)
Fannkuch11              4.41s × (0.98,1.03)   4.35s × (1.00,1.00)     ~    (p=0.090)
FmtFprintfEmpty        92.7ns × (0.91,1.16)  86.0ns × (0.94,1.11)   -7.31% (p=0.038)
FmtFprintfString        281ns × (0.96,1.08)   276ns × (0.98,1.04)     ~    (p=0.219)
FmtFprintfInt           288ns × (0.97,1.06)   274ns × (0.98,1.06)   -4.94% (p=0.002)
FmtFprintfIntInt        493ns × (0.97,1.04)   506ns × (0.99,1.01)   +2.65% (p=0.009)
FmtFprintfPrefixedInt   423ns × (0.97,1.04)   391ns × (0.99,1.01)   -7.52% (p=0.000)
FmtFprintfFloat         598ns × (0.99,1.01)   566ns × (0.99,1.01)   -5.27% (p=0.000)
FmtManyArgs            1.89µs × (0.98,1.05)  1.91µs × (0.99,1.01)     ~    (p=0.231)
GobDecode              14.8ms × (0.98,1.03)  15.3ms × (0.99,1.02)   +3.01% (p=0.000)
GobEncode              12.3ms × (0.98,1.01)  11.5ms × (0.97,1.03)   -5.93% (p=0.000)
Gzip                    656ms × (0.99,1.05)   645ms × (0.99,1.01)     ~    (p=0.055)
Gunzip                  142ms × (1.00,1.00)   142ms × (1.00,1.00)   -0.32% (p=0.034)
HTTPClientServer       91.2µs × (0.97,1.04)  90.5µs × (0.97,1.04)     ~    (p=0.468)
JSONEncode             32.6ms × (0.97,1.08)  32.0ms × (0.98,1.03)     ~    (p=0.190)
JSONDecode              114ms × (0.97,1.05)   114ms × (0.99,1.01)     ~    (p=0.887)
Mandelbrot200          6.11ms × (0.98,1.04)  6.04ms × (1.00,1.01)     ~    (p=0.167)
GoParse                6.66ms × (0.97,1.04)  6.47ms × (0.97,1.05)   -2.81% (p=0.014)
RegexpMatchEasy0_32     159ns × (0.99,1.00)   171ns × (0.93,1.07)   +7.19% (p=0.002)
RegexpMatchEasy0_1K     538ns × (1.00,1.01)   550ns × (0.98,1.01)   +2.30% (p=0.000)
RegexpMatchEasy1_32     138ns × (1.00,1.00)   135ns × (0.99,1.02)   -1.60% (p=0.000)
RegexpMatchEasy1_1K     869ns × (0.99,1.01)   879ns × (1.00,1.01)   +1.08% (p=0.000)
RegexpMatchMedium_32    252ns × (0.99,1.01)   243ns × (1.00,1.00)   -3.71% (p=0.000)
RegexpMatchMedium_1K   72.7µs × (1.00,1.00)  70.3µs × (1.00,1.00)   -3.34% (p=0.000)
RegexpMatchHard_32     3.85µs × (1.00,1.00)  3.82µs × (1.00,1.01)   -0.81% (p=0.000)
RegexpMatchHard_1K      118µs × (1.00,1.00)   117µs × (1.00,1.00)   -0.56% (p=0.000)
Revcomp                 920ms × (0.97,1.07)   917ms × (0.97,1.04)     ~    (p=0.808)
Template                129ms × (0.98,1.03)   114ms × (0.99,1.01)  -12.06% (p=0.000)
TimeParse               619ns × (0.99,1.01)   622ns × (0.99,1.01)     ~    (p=0.062)
TimeFormat              661ns × (0.98,1.04)   665ns × (0.99,1.01)     ~    (p=0.524)

See next CL for combination with a similar optimization for slice.
The benchmarks that are slower in this CL are still faster overall
with the combination of the two.

Change-Id: I2a7421658091b2488c64741b4db15ab6c3b4cb7e
Reviewed-on: https://go-review.googlesource.com/9812
Reviewed-by: David Chase <drchase@google.com>
2015-05-12 17:55:09 +00:00
Russ Cox
3f209abb29 cmd/internal/gc: detect bad append(f()) during type check
Today's earlier fix can stay, but it's a band-aid over the real problem,
which is that bad code was slipping through the type checker
into the back end (and luckily causing a type error there).

I discovered this because my new append does not use the same
temporaries and failed the test as written.

Fixes #9521.

Change-Id: I7e33e2ea15743406e15c6f3fdf73e1edecda69bd
Reviewed-on: https://go-review.googlesource.com/9921
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-12 16:26:35 +00:00
Didier Spezia
7c0db1b7e2 cmd/gc: do not display ~b identifiers in error messages
Instead of errors like:

./blank2.go:15: cannot use ~b1 (type []int) as type int in assignment

we now have:

./blank2.go:15: cannot use _ (type []int) as type int in assignment

Less confusing for users.

Fixes #9521

Change-Id: Ieab9859040e8e0df95deeaee7eeb408d3be61c0f
Reviewed-on: https://go-review.googlesource.com/9902
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-11 17:44:31 +00:00
Josh Bleecher Snyder
a3dfcf51c6 cmd/internal/gc: unsafe.Pointer constants may only be converted to uintptr
Fixes #8927.

Change-Id: I638cddd439dd2d4eeef5474118cfcbde0c8a5a43
Reviewed-on: https://go-review.googlesource.com/9632
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: David Chase <drchase@google.com>
2015-05-07 23:54:28 +00:00