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2563 Commits

Author SHA1 Message Date
Matthew Dempsky
70544c91ff cmd/compile/internal/syntax: match old parser errors and line numbers
This makes a bunch of changes to package syntax to tweak line numbers
for AST nodes. For example, short variable declaration statements are
now associated with the location of the ":=" token, and function calls
are associated with the location of the final ")" token. These help
satisfy many unit tests that assume the old parser's behavior.

Because many of these changes are questionable, they're guarded behind
a new "gcCompat" const to make them easy to identify and revisit in
the future.

A handful of remaining tests are too difficult to make behave
identically. These have been updated to execute with -newparser=0 and
comments explaining why they need to be fixed.

all.bash now passes with both the old and new parsers.

Change-Id: Iab834b71ca8698d39269f261eb5c92a0d55a3bf4
Reviewed-on: https://go-review.googlesource.com/27199
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-08-19 01:10:21 +00:00
David Chase
5b9ff11c3d cmd/compile: ppc64le working, not optimized enough
This time with the cherry-pick from the proper patch of
the old CL.

Stack size increased.
Corrected NaN-comparison glitches.
Marked g register as clobbered by calls.
Fixed shared libraries.

live_ssa.go still disabled because of differences.
Presumably turning on more optimization will fix
both the stack size and the live_ssa.go glitches.

Enhanced debugging output for shared libs test.

Rebased onto master.

Updates #16010.

Change-Id: I40864faf1ef32c118fb141b7ef8e854498e6b2c4
Reviewed-on: https://go-review.googlesource.com/27159
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2016-08-18 16:34:47 +00:00
Cherry Zhang
3d5cf72ca9 cmd/compile: CSE copied tuple selectors
In CSE if a tuple generator is CSE'd to a different block, its
selectors are copied to the same block. In this case, also CES
the copied selectors.

Test copied from Keith's CL 27202.

Fixes #16741.

Change-Id: I2fc8b9513d430f10d6104275cfff5fb75d3ef3d9
Reviewed-on: https://go-review.googlesource.com/27236
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2016-08-17 21:03:26 +00:00
Cherry Zhang
04e76f295f test: add test for CL 26831
Test nil check removal for access of PAUTOHEAP.

Change-Id: Id739a9cda7cd3ff173bdcccfedcad93ee90711ef
Reviewed-on: https://go-review.googlesource.com/27232
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-08-17 14:50:34 +00:00
Josh Bleecher Snyder
615a52b95b cmd/compile: inline x, ok := y.(T) where T is a scalar
When T is a scalar, there are no runtime calls
required, which makes this a clear win.

encoding/binary:
WriteInts-8                958ns ± 3%     864ns ± 2%   -9.80%  (p=0.000 n=15+15)

This also considerably shrinks a core fmt
routine:

Before: "".(*pp).printArg t=1 size=3952 args=0x20 locals=0xf0
After:  "".(*pp).printArg t=1 size=2624 args=0x20 locals=0x98

Unfortunately, I find it very hard to get stable
numbers out of the fmt benchmarks due to thermal scaling.

Change-Id: I1278006b030253bf8e48dc7631d18985cdaa143d
Reviewed-on: https://go-review.googlesource.com/26659
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
2016-08-17 01:12:01 +00:00
Keith Randall
a16a189fb9 test: remove unused variable
ssaMain is no longer needed.

Change-Id: I0b77f0bcd482329d73018bd80a6e068e622e191b
Reviewed-on: https://go-review.googlesource.com/27190
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-08-16 21:46:54 +00:00
Keith Randall
64214792e2 cmd/compile: allow unsafe.Pointer(nil) as static data
Fixes #16306

Change-Id: If8e2f411fe9a5a5c198f10765fee7261ba8feaf2
Reviewed-on: https://go-review.googlesource.com/24836
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-08-16 17:47:50 +00:00
Robert Griesemer
c7b9bd7456 cmd/compile: don't crash when exporting self-recursive interfaces
For #16369.

Change-Id: I4c9f5a66b95558adcc1bcface164b9b2b4382d2f
Reviewed-on: https://go-review.googlesource.com/24979
Reviewed-by: Alan Donovan <adonovan@google.com>
2016-08-16 17:07:03 +00:00
Keith Randall
d251030fa6 cmd/compile: don't fold >32bit constants into a MULQ
Don't fold constant factors into a multiply
beyond the capacity of a MULQ instruction (32 bits).

Fixes #16733

Change-Id: Idc213c6cb06f7c94008a8cf9e60a9e77d085fd89
Reviewed-on: https://go-review.googlesource.com/27160
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-08-16 16:46:48 +00:00
Cherry Zhang
d99cee79b9 [dev.ssa] cmd/compile, etc.: more ARM64 optimizations, and enable SSA by default
Add more ARM64 optimizations:
- use hardware zero register when it is possible.
- use shifted ops.
  The assembler supports shifted ops but not documented, nor knows
  how to print it. This CL adds them.
- enable fast division.
  This was disabled because it makes the old backend generate slower
  code. But with SSA it generates faster code.

Turn on SSA by default, also adjust tests.

Change-Id: I7794479954c83bb65008dcb457bc1e21d7496da6
Reviewed-on: https://go-review.googlesource.com/26950
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-08-15 03:37:34 +00:00
Keith Randall
c069bc4996 [dev.ssa] cmd/compile: implement GO386=387
Last part of the 386 SSA port.

Modify the x86 backend to simulate SSE registers and
instructions with 387 registers and instructions.
The simulation isn't terribly performant, but it works,
and the old implementation wasn't very performant either.
Leaving to people who care about 387 to optimize if they want.

Turn on SSA backend for 386 by default.

Fixes #16358

Change-Id: I678fb59132620b2c47e993c1c10c4c21135f70c0
Reviewed-on: https://go-review.googlesource.com/25271
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-08-10 17:41:01 +00:00
Keith Randall
69a755b602 [dev.ssa] cmd/compile: port SSA backend to amd64p32
It's not a new backend, just a PtrSize==4 modification
of the existing AMD64 backend.

Change-Id: Icc63521a5cf4ebb379f7430ef3f070894c09afda
Reviewed-on: https://go-review.googlesource.com/25586
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-08-09 15:48:26 +00:00
Keith Randall
d2286ea284 [dev.ssa] Merge remote-tracking branch 'origin/master' into mergebranch
Semi-regular merge from tip into dev.ssa.

Change-Id: Iadb60e594ef65a99c0e1404b14205fa67c32a9e9
2016-08-04 10:08:20 -07:00
Cherry Zhang
111d590f86 cmd/compile: fix possible spill of invalid pointer with DUFFZERO on AMD64
SSA compiler on AMD64 may spill Duff-adjusted address as scalar. If
the object is on stack and the stack moves, the spilled address become
invalid.

Making the spill pointer-typed does not work. The Duff-adjusted address
points to the memory before the area to be zeroed and may be invalid.
This may cause stack scanning code panic.

Fix it by doing Duff-adjustment in genValue, so the intermediate value
is not seen by the reg allocator, and will not be spilled.

Add a test to cover both cases. As it depends on allocation, it may
be not always triggered.

Fixes #16515.

Change-Id: Ia81d60204782de7405b7046165ad063384ede0db
Reviewed-on: https://go-review.googlesource.com/25309
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-07-29 01:09:55 +00:00
Cherry Zhang
6b6de15d32 [dev.ssa] cmd/compile: support NaCl in SSA for ARM
NaCl code runs in sandbox and there are restrictions for its
instruction uses
(https://developer.chrome.com/native-client/reference/sandbox_internals/arm-32-bit-sandbox).

Like the legacy backend, on NaCl,
- don't use R9, which is used as NaCl's "thread pointer".
- don't use Duff's device.
- don't use indexed load/stores.
- the assembler rewrites DIV/MOD to runtime calls, which on NaCl
  clobbers R12, so R12 is marked as clobbered for DIV/MOD.
- other restrictions are satisfied by the assembler.

Enable SSA specific tests on nacl/arm, and disable non-SSA ones.

Updates #15365.

Change-Id: I9262693ec6756b89ca29d3ae4e52a96fe5403b02
Reviewed-on: https://go-review.googlesource.com/24859
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-07-16 03:13:45 +00:00
Keith Randall
efefd11725 [dev.ssa] Merge remote-tracking branch 'origin/master' into mergebranch
Semi-regular merge of tip into dev.ssa.

Change-Id: I855817c4746237792a2dab6eaf471087a3646be4
2016-07-13 11:12:44 -07:00
Ian Lance Taylor
bbe5da4260 cmd/compile, syscall: add //go:uintptrescapes comment, and use it
This new comment can be used to declare that the uintptr arguments to a
function may be converted from pointers, and that those pointers should
be considered to escape. This is used for the Call methods in
dll_windows.go that take uintptr arguments, because they call Syscall.

We can't treat these functions as we do syscall.Syscall, because unlike
Syscall they may cause the stack to grow. For Syscall we can assume that
stack arguments can remain on the stack, but for these functions we need
them to escape.

Fixes #16035.

Change-Id: Ia0e5b4068c04f8d303d95ab9ea394939f1f57454
Reviewed-on: https://go-review.googlesource.com/24551
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-07-06 20:48:41 +00:00
Cherry Zhang
42181ad852 [dev.ssa] cmd/compile: enable SSA on ARM by default
As Josh mentioned in CL 24716, there has been requests for using SSA
for ARM. SSA can still be disabled by setting -ssa=0 for cmd/compile,
or partially enabled with GOSSAFUNC, GOSSAPKG, and GOSSAHASH.

Not enable SSA by default on NaCl, which is not supported yet.

Enable SSA-specific tests on ARM: live_ssa.go and nilptr3_ssa.go;
disable non-SSA tests: live.go, nilptr3.go, and slicepot.go.

Updates #15365.

Change-Id: Ic2ca8d166aeca8517b9d262a55e92f2130683a16
Reviewed-on: https://go-review.googlesource.com/23953
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
2016-07-06 15:05:50 +00:00
Ian Lance Taylor
519b469795 cmd/compile: mark live heap-allocated pparamout vars as needzero
If we don't mark them as needzero, we have a live pointer variable
containing possible garbage, which will baffle the GC.

Fixes #16249.

Change-Id: I7c423ceaca199ddd46fc2c23e5965e7973f07584
Reviewed-on: https://go-review.googlesource.com/24715
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-07-02 00:40:40 +00:00
Konstantin Shaposhnikov
85a4f44745 cmd/vet: make checking example names in _test packages more robust
Prior to this change package "foo" had to be installed in order to check
example names in "foo_test" package.

However by the time "foo_test" package is checked a parsed "foo" package
has been already constructed. Use it to check example names.

Also change TestDivergentPackagesExamples test to pass directory of the
package to the vet tool as it is the most common way to invoke it. This
requires changes to errchk to add support for grabbing source files from
a directory.

Fixes #16189

Change-Id: Ief103d07b024822282b86c24250835cc591793e8
Reviewed-on: https://go-review.googlesource.com/24488
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-28 22:09:00 +00:00
Ian Lance Taylor
e0f986bf26 cmd/compile: avoid function literal name collision with "glob"
The compiler was treating all global function literals as occurring in a
function named "glob", which caused a symbol name collision when there
was an actual function named "glob".  Fixed by adding a period.

Fixes #16193.

Change-Id: I67792901a8ca04635ba41d172bfaee99944f594d
Reviewed-on: https://go-review.googlesource.com/24500
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-06-27 21:05:28 +00:00
Keith Randall
6effdd28de cmd/compile: keep heap pointer for escaping output parameters live
Make sure the pointer to the heap copy of an output parameter is kept
live throughout the function.  The function could panic at any point,
and then a defer could recover.  Thus, we need the pointer to the heap
copy always available so the post-deferreturn code can copy the return
value back to the stack.

Before this CL, the pointer to the heap copy could be considered dead in
certain situations, like code which is reverse dominated by a panic call.

Fixes #16095.

Change-Id: Ic3800423e563670e5b567b473bf4c84cddb49a4c
Reviewed-on: https://go-review.googlesource.com/24213
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-06-27 16:48:48 +00:00
Robert Griesemer
1f446432dd cmd/compile: fix error msg mentioning different packages with same name
This is a regression from 1.6. The respective code in importimport
(export.go) was not exactly replicated with the new importer. Also
copied over the missing cyclic import check.

Added test cases.

Fixes #16133.

Change-Id: I1e0a39ff1275ca62a8054874294d400ed83fb26a
Reviewed-on: https://go-review.googlesource.com/24312
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
2016-06-22 00:12:55 +00:00
Robert Griesemer
845992eeed test: add -s flag to commands understood by run.go
If -s is specified, each file is considered a separate
package even if multiple files have the same package names.

For instance, the action and flag "errorcheckdir -s"
will compile all files in the respective directory as
individual packages.

Change-Id: Ic5c2f9e915a669433f66c2d3fe0ac068227a502f
Reviewed-on: https://go-review.googlesource.com/24313
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-06-22 00:06:19 +00:00
Ian Lance Taylor
09834d1c08 runtime: panic with the right error on iface conversion
A straight conversion from a type T to an interface type I, where T does
not implement I, should always panic with an interface conversion error
that shows the missing method.  This was not happening if the conversion
was done once using the comma-ok form (the result would not be OK) and
then again in a straight conversion.  Due to an error in the runtime
package the second conversion was failing with a nil pointer
dereference.

Fixes #16130.

Change-Id: I8b9fca0f1bb635a6181b8b76de8c2385bb7ac2d2
Reviewed-on: https://go-review.googlesource.com/24284
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michel Lespinasse <walken@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-06-21 01:43:42 +00:00
Ian Lance Taylor
e1a6e71e74 test: add missing copyright notice
Change-Id: I2a5353203ca2958fa37fc7a5ea3f22ad4fc62b0e
Reviewed-on: https://go-review.googlesource.com/24282
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-06-20 23:46:33 +00:00
David Crawshaw
af0fc83985 cmd/compile, etc: handle many struct fields
This adds 8 bytes of binary size to every type that has methods. It is
the smallest change I could come up with for 1.7.

Fixes #16037

Change-Id: Ibe15c3165854a21768596967757864b880dbfeed
Reviewed-on: https://go-review.googlesource.com/24070
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-14 15:32:34 +00:00
David Chase
595426c0d9 cmd/compile: fix OASWB rewriting in racewalk
Special case for rewriting OAS inits omitted OASWB, added
that and OAS2FUNC.  The special case cannot be default case,
that causes racewalk to fail in horrible ways.

Fixes #16008.

Change-Id: Ie0d2f5735fe9d8255a109597b36d196d4f86703a
Reviewed-on: https://go-review.googlesource.com/23954
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-12 23:58:25 +00:00
Keith Randall
e3f1c66f31 cmd/compile: for tail calls in stubs, ensure args are alive
The generated code for interface stubs sometimes just messes
with a few of the args and then tail-calls to the target routine.
The args that aren't explicitly modified appear to not be used.
But they are used, by the thing we're tail calling.

Fixes #16016

Change-Id: Ib9b3a8311bb714a201daee002885fcb59e0463fa
Reviewed-on: https://go-review.googlesource.com/23960
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-06-09 19:32:51 +00:00
Cherry Zhang
f3689d1382 cmd/compile: nilcheck interface value in go/defer interface call for SSA
This matches the behavior of the legacy backend.

Fixes #15975 (if this is the intended behavior)

Change-Id: Id277959069b8b8bf9958fa8f2cbc762c752a1a19
Reviewed-on: https://go-review.googlesource.com/23820
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-08 20:35:53 +00:00
Keith Randall
afad74ec30 cmd/compile: cgen_append can handle complex targets
Post-liveness fix, the slices on both sides can now be
indirects of & variables.  The cgen code handles those
cases just fine.

Fixes #15988

Change-Id: I378ad1d5121587e6107a9879c167291a70bbb9e4
Reviewed-on: https://go-review.googlesource.com/23863
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-06-08 00:01:09 +00:00
Keith Randall
2f088884ae cmd/compile: use fake package for allocating autos
Make sure auto names don't conflict with function names. Before this CL,
we confused name a.len (the len field of the slice a) with a.len (the function
len declared on a).

Fixes #15961

Change-Id: I14913de697b521fb35db9a1b10ba201f25d552bb
Reviewed-on: https://go-review.googlesource.com/23789
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-07 06:04:23 +00:00
Ian Lance Taylor
6901b08482 cmd/link: avoid name collision with DWARF .def suffix
Adding a .def suffix for DWARF info collided with the DWARF info,
without the suffix, for a method named def. Change the suffix to ..def
instead.

Fixes #15926.

Change-Id: If1bf1bcb5dff1d7f7b79f78e3f7a3bbfcd2201bb
Reviewed-on: https://go-review.googlesource.com/23733
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-06-03 16:56:29 +00:00
Robert Griesemer
bbd1dcdf7d cmd/compile: correctly export underlying type of predecl. error type
Fixes #15920.

Change-Id: I78cd79b91a58d0f7218b80f9445417f4ee071a6e
Reviewed-on: https://go-review.googlesource.com/23606
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-01 21:32:46 +00:00
Keith Randall
52fe472472 cmd/compile: for arm, zero unaligned memory 1 byte at a time
If memory might be unaligned, zero it one byte at a time
instead of 4 bytes at a time.

Fixes #15902

Change-Id: I4eff0840e042e2f137c1a4028f08793eb7dfd703
Reviewed-on: https://go-review.googlesource.com/23587
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2016-06-01 14:14:13 +00:00
Josh Bleecher Snyder
8003e79154 test: add more switch error handling tests
Some of these errors are reported in the wrong places.
That’s issue #15911 and #15912.

Change-Id: Ia09d7f89be4d15f05217a542a61b6ac08090dd87
Reviewed-on: https://go-review.googlesource.com/23588
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-31 22:29:36 +00:00
Josh Bleecher Snyder
0e13dbc1a9 cmd/compile: disallow multiple nil cases in a type switch
Fixes #15898.

Change-Id: I66e2ad21f283563c7142aa820f0354711d964768
Reviewed-on: https://go-review.googlesource.com/23573
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
2016-05-31 20:31:00 +00:00
Russ Cox
b6dc3e6f66 cmd/compile: fix liveness computation for heap-escaped parameters
The liveness computation of parameters generally was never
correct, but forcing all parameters to be live throughout the
function covered up that problem. The new SSA back end is
too clever: even though it currently keeps the parameter values live
throughout the function, it may find optimizations that mean
the current values are not written back to the original parameter
stack slots immediately or ever (for example if a parameter is set
to nil, SSA constant propagation may replace all later uses of the
parameter with a constant nil, eliminating the need to write the nil
value back to the stack slot), so the liveness code must now
track the actual operations on the stack slots, exposing these
problems.

One small problem in the handling of arguments is that nodarg
can return ONAME PPARAM nodes with adjusted offsets, so that
there are actually multiple *Node pointers for the same parameter
in the instruction stream. This might be possible to correct, but
not in this CL. For now, we fix this by using n.Orig instead of n
when considering PPARAM and PPARAMOUT nodes.

The major problem in the handling of arguments is general
confusion in the liveness code about the meaning of PPARAM|PHEAP
and PPARAMOUT|PHEAP nodes, especially as contrasted with PAUTO|PHEAP.
The difference between these two is that when a local variable "moves"
to the heap, it's really just allocated there to start with; in contrast,
when an argument moves to the heap, the actual data has to be copied
there from the stack at the beginning of the function, and when a
result "moves" to the heap the value in the heap has to be copied
back to the stack when the function returns
This general confusion is also present in the SSA back end.

The PHEAP bit worked decently when I first introduced it 7 years ago (!)
in 391425ae. The back end did nothing sophisticated, and in particular
there was no analysis at all: no escape analysis, no liveness analysis,
and certainly no SSA back end. But the complications caused in the
various downstream consumers suggest that this should be a detail
kept mainly in the front end.

This CL therefore eliminates both the PHEAP bit and even the idea of
"heap variables" from the back ends.

First, it replaces the PPARAM|PHEAP, PPARAMOUT|PHEAP, and PAUTO|PHEAP
variable classes with the single PAUTOHEAP, a pseudo-class indicating
a variable maintained on the heap and available by indirecting a
local variable kept on the stack (a plain PAUTO).

Second, walkexpr replaces all references to PAUTOHEAP variables
with indirections of the corresponding PAUTO variable.
The back ends and the liveness code now just see plain indirected
variables. This may actually produce better code, but the real goal
here is to eliminate these little-used and somewhat suspect code
paths in the back end analyses.

The OPARAM node type goes away too.

A followup CL will do the same to PPARAMREF. I'm not sure that
the back ends (SSA in particular) are handling those right either,
and with the framework established in this CL that change is trivial
and the result clearly more correct.

Fixes #15747.

Change-Id: I2770b1ce3cbc93981bfc7166be66a9da12013d74
Reviewed-on: https://go-review.googlesource.com/23393
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-27 03:19:52 +00:00
Robert Griesemer
30282b091d cmd/compile: correctly import labels, gotos, and fallthroughs
The importer had several bugs with respect to labels and gotos:
- it didn't create a new ONAME node for label names (label dcl,
  goto, continue, and break)
- it overwrote the symbol for gotos with the dclstack
- it didn't set the dclstack for labels

In the process changed export format slightly to always assume
a label name for labels and gotos, and never assume a label for
fallthroughs.

For fallthroughs and switch cases, now also set Xoffset like in
the parser. (Not setting it, i.e., using 0 was ok since this is
only used for verifying correct use of fallthroughs, which was
checked already. But it's an extra level of verification of the
import.)

Fixes #15838.

Change-Id: I3637f6314b8651c918df0c8cd70cd858c92bd483
Reviewed-on: https://go-review.googlesource.com/23445
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-26 00:32:03 +00:00
Russ Cox
85e3c9e6b8 cmd/compile, go/types: omit needless word in error message
CL 21462 and CL 21463 made this message say explicitly that the problem
was a struct field in a map, but the word "directly" is unnecessary,
sounds wrong, and makes the error long.

Change-Id: I2fb68cdaeb8bd94776b8022cf3eae751919ccf6f
Reviewed-on: https://go-review.googlesource.com/23373
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-05-24 15:07:16 +00:00
Robert Griesemer
448246adff cmd/compile: don't exit early because of hidden error messages
Non-syntax errors are always counted to determine if to exit
early, but then deduplication eliminates them. This can lead
to situations which report "too many errors" and only one
error is shown.

De-duplicate non-syntax errors early, at least the ones that
appear consecutively, and only count the ones actually being
shown. This doesn't work perfectly as they may not appear in
sequence, but it's cheap and good enough.

Fixes #14136.

Change-Id: I7b11ebb2e1e082f0d604b88e544fe5ba967af1d7
Reviewed-on: https://go-review.googlesource.com/23259
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-05-19 23:17:54 +00:00
Keith Randall
d603c27c6b cmd/compile: large ptr literals must escape
They get rewritten to NEWs, and they must be marked as escaping
so walk doesn't try to allocate them back onto the stack.

Fixes #15733

Change-Id: I433033e737c3de51a9e83a5a273168dbc9110b74
Reviewed-on: https://go-review.googlesource.com/23223
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-05-19 15:12:01 +00:00
Keith Randall
075880a8e8 cmd/compile: fix build
Run live vars test only on ssa builds.
We can't just drop KeepAlive ops during regalloc.  We need
to replace them with copies.

Change-Id: Ib4b3b1381415db88fdc2165fc0a9541b73ad9759
Reviewed-on: https://go-review.googlesource.com/23225
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-05-18 20:44:00 +00:00
Keith Randall
3572c6418b cmd/compile: keep pointer input arguments live throughout function
Introduce a KeepAlive op which makes sure that its argument is kept
live until the KeepAlive.  Use KeepAlive to mark pointer input
arguments as live after each function call and at each return.

We do this change only for pointer arguments.  Those are the
critical ones to handle because they might have finalizers.
Doing compound arguments (slices, structs, ...) is more complicated
because we would need to track field liveness individually (we do
that for auto variables now, but inputs requires extra trickery).

Turn off the automatic marking of args as live.  That way, when args
are explicitly nulled, plive will know that the original argument is
dead.

The KeepAlive op will be the eventual implementation of
runtime.KeepAlive.

Fixes #15277

Change-Id: I5f223e65d99c9f8342c03fbb1512c4d363e903e5
Reviewed-on: https://go-review.googlesource.com/22365
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-05-18 19:25:27 +00:00
Matthew Dempsky
c65647d620 cmd/compile: handle unsafe.Pointer(f()) correctly
Previously statements like

    f(unsafe.Pointer(g()), int(h()))

would be reordered into a sequence of statements like

    autotmp_g := g()
    autotmp_h := h()
    f(unsafe.Pointer(autotmp_g), int(autotmp_h))

which can leave g's temporary value on the stack as a uintptr, rather
than an unsafe.Pointer. Instead, recognize uintptr-to-unsafe.Pointer
conversions when reordering function calls to instead produce:

    autotmp_g := unsafe.Pointer(g())
    autotmp_h := h()
    f(autotmp_g, int(autotmp_h))

Fixes #15329.

Change-Id: I2cdbd89d233d0d5c94791513a9fd5fd958d11ed5
Reviewed-on: https://go-review.googlesource.com/22273
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-05-18 14:01:22 +00:00
Robert Griesemer
aff4889089 cmd/compile: clean up encoding of method expressions and add test
Fixes #15646.

Change-Id: Ic13d1adc0a358149209195cdb03811eeee506fb8
Reviewed-on: https://go-review.googlesource.com/23052
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-05-11 19:23:04 +00:00
Keith Randall
9e96ad851d test: add test for unlowered ITab
See #15604.  This was a bug in a CL that has since been
rolled back.  Adding a test to challenge the next attempter.

Change-Id: Ic43be254ea6eaab0071018cdc61d9b1c21f19cbf
Reviewed-on: https://go-review.googlesource.com/23000
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-05-10 16:30:34 +00:00
David Chase
3c09001917 cmd/compile: correct sparseSet probes in regalloc to avoid index error
In regalloc, a sparse map is preallocated for later use by
spill-in-loop sinking.  However, variables (spills) are added
during register allocation before spill sinking, and a map
query involving any of these new variables will index out of
bounds in the map.

To fix:
1) fix the queries to use s.orig[v.ID].ID instead, to ensure
proper indexing.  Note that s.orig will be nil for values
that are not eligible for spilling (like memory and flags).

2) add a test.

Fixes #15585.

Change-Id: I8f2caa93b132a0f2a9161d2178320d5550583075
Reviewed-on: https://go-review.googlesource.com/22911
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-09 18:35:44 +00:00
Russ Cox
feb6131b1a cmd/compile: add -linkobj flag to allow writing object file in two parts
This flag is experimental and the semantics may change
even after Go 1.7 is released. There are no changes to code
not using the flag.

The first part is for reading by future compiles.
The second part is for reading by the final link step.
Splitting the file this way allows distributed build systems
to ship the compile-input part only to compile steps and
the linker-input part only to linker steps.

The first part is basically just the export data,
and the second part is basically everything else.
The overall files still have the same broad structure,
so that existing tools will work with both halves.
It's just that various pieces are empty in the two halves.

This also copies the two bits of data the linker needed from
export data into the object header proper, so that the linker
doesn't need any export data at all. That eliminates a TODO
that was left for switching to the binary export data.
(Now the linker doesn't need to know about the switch.)

The default is still to write out a combined output file.
Nothing changes unless you pass -linkobj to the compiler.
There is no support in the go command for -linkobj,
since the go command doesn't copy objects around.
The expectation is that other build systems (like bazel, say)
might take advantage of this.

The header adjustment and the option for the split output
was intended as part of the zip archives, but the zip archives
have been cut from Go 1.7. Doing this to the current archives
both unblocks one step in the switch to binary export data
and enables alternate build systems to experiment with the
new flag using the Go 1.7 release.

Change-Id: I8b6eab25b8a22b0a266ba0ac6d31e594f3d117f3
Reviewed-on: https://go-review.googlesource.com/22500
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-05-09 17:31:45 +00:00
Robert Griesemer
87a2ae1fa2 cmd/compile: fix binary export of composite literals with implicit types
Also:
- replaced remaining panics with Fatal calls
- more comments

Fixes #15572.

Change-Id: Ifb27e80b66700f5692a84078764a1e928d4b310d
Reviewed-on: https://go-review.googlesource.com/22935
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-05-09 06:16:07 +00:00
Josh Bleecher Snyder
3696e469e5 test: add test for issue 15602
The problem was fixed by the rollback in CL 22930.
This CL just adds a test to prevent regressions.

Fixes #15602

Change-Id: I37453f6e18ca43081266fe7f154c6d63fbaffd9b
Reviewed-on: https://go-review.googlesource.com/22931
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-05-08 22:59:43 +00:00
Matthew Dempsky
55546efeee Revert "cmd/compile: properly handle map assignments for OAS2DOTTYPE"
This reverts commit 9d7c9b4384.

For #15602.

Change-Id: I464184b05babe4cb8dedab6161efa730cea6ee2d
Reviewed-on: https://go-review.googlesource.com/22930
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-08 20:15:04 +00:00
Robert Griesemer
394ac818b0 cmd/compile: add and enable (internal) option to only track named types
The new export format keeps track of all types that are exported.
If a type is seen that was exported before, only a reference to
that type is emitted. The importer maintains a list of all the
seen types and uses that list to resolve type references.

The existing compiler infrastructure's invariants assumes that
only named types are referred to before they are fully set up.
Referring to unnamed incomplete types causes problems. One of
the issues was #15548.

Added a new internal flag 'trackAllTypes' to enable/disable
this type tracking. With this change only named types are
tracked.

Verified that this fix also addresses #15548, even w/o the
prior fix for that issue (in fact that prior fix is turned
off if trackAllTypes is disabled because it's not needed).

The test for #15548 covers also this change.

For #15548.

Change-Id: Id0b3ff983629703d025a442823f99649fd728a56
Reviewed-on: https://go-review.googlesource.com/22839
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-05-07 23:56:02 +00:00
Tal Shprecher
9d7c9b4384 cmd/compile: properly handle map assignments for OAS2DOTTYPE
The boolean destination in an OAS2DOTTYPE expression craps out during
compilation when trying to assign to a map entry because, unlike slice entries,
map entries are not directly addressable in memory. The solution is to
properly order the boolean destination node so that map entries are set
via autotmp variables.

Fixes #14678

Change-Id: If344e8f232b5bdac1b53c0f0d21eeb43ab17d3de
Reviewed-on: https://go-review.googlesource.com/22833
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-07 08:00:39 +00:00
Robert Griesemer
d68f800620 test: update test for issue 15548
Accidentally checked in the version of file c.go that doesn't
exhibit the bug - hence the test was not testing the bug fix.
Double-checked that this version exposes the bug w/o the fix.

Change-Id: Ie4dc455229d1ac802a80164b5d549c2ad4d971f5
Reviewed-on: https://go-review.googlesource.com/22837
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-06 02:50:42 +00:00
Robert Griesemer
8650c23034 cmd/compile: verify imported types after they are fully imported
Fixes #15548.

Change-Id: I1dfa9c8739a4b6d5e4c737c1a1e09e80e045b7aa
Reviewed-on: https://go-review.googlesource.com/22803
Reviewed-by: Alan Donovan <adonovan@google.com>
2016-05-05 20:31:30 +00:00
Cherry Zhang
04a30025db test: enable fixedbugs/issue10607.go test on linux/mips64x
external linking is now supported.

Change-Id: I13e90c39dad86e60781adecdbe8e6bc9e522f740
Reviewed-on: https://go-review.googlesource.com/19811
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-04 16:42:08 +00:00
Emmanuel Odeke
53fd522c0d all: make copyright headers consistent with one space after period
Follows suit with https://go-review.googlesource.com/#/c/20111.

Generated by running
$ grep -R 'Go Authors.  All' * | cut -d":" -f1 | while read F;do perl -pi -e 's/Go
Authors.  All/Go Authors. All/g' $F;done

The code in cmd/internal/unvendor wasn't changed.

Fixes #15213

Change-Id: I4f235cee0a62ec435f9e8540a1ec08ae03b1a75f
Reviewed-on: https://go-review.googlesource.com/21819
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-02 13:43:18 +00:00
David Chase
d8d33514f9 cmd/compile: Move divconst_test out of test/bench/go1
This is necessary to avoid disrupting the go1 suite and gives
us a place to put other tests of basic compiler function and
correctness.

Change-Id: I36933819ff2bfe6a2121fff2be9a98efd2123d9a
Reviewed-on: https://go-review.googlesource.com/22597
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-29 16:20:18 +00:00
Robert Griesemer
d954f9c4d1 test: added test case for (fixed) issue 15470
Follow-up to https://golang.org/cl/22543.

Change-Id: I873b4fa6616ac2aea8faada2fccd126233bbc07f
Reviewed-on: https://go-review.googlesource.com/22583
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-29 00:42:13 +00:00
Austin Clements
b49b71ae19 runtime: don't rescan globals
Currently the runtime rescans globals during mark 2 and mark
termination. This costs as much as 500µs/MB in STW time, which is
enough to surpass the 10ms STW limit with only 20MB of globals.

It's also basically unnecessary. The compiler already generates write
barriers for global -> heap pointer updates and the regular write
barrier doesn't check whether the slot is a global or in the heap.
Some less common write barriers do cause problems.
heapBitsBulkBarrier, which is used by typedmemmove and related
functions, currently depends on having access to the pointer bitmap
and as a result ignores writes to globals. Likewise, the
reflect-related write barriers reflect_typedmemmovepartial and
callwritebarrier ignore non-heap destinations; though it appears they
can never be called with global pointers anyway.

This commit makes heapBitsBulkBarrier issue write barriers for writes
to global pointers using the data and BSS pointer bitmaps, removes the
inheap checks from the reflection write barriers, and eliminates the
rescans during mark 2 and mark termination. It also adds a test that
writes to globals have write barriers.

Programs with large data+BSS segments (with pointers) aren't common,
but for programs that do have large data+BSS segments, this
significantly reduces pause time:

name \ 95%ile-time/markTerm              old         new  delta
LargeBSS/bss:1GB/gomaxprocs:4  148200µs ± 6%  302µs ±52%  -99.80% (p=0.008 n=5+5)

This very slightly improves the go1 benchmarks:

name                      old time/op    new time/op    delta
BinaryTree17-12              2.62s ± 3%     2.62s ± 4%    ~     (p=0.904 n=20+20)
Fannkuch11-12                2.15s ± 1%     2.13s ± 0%  -1.29%  (p=0.000 n=18+20)
FmtFprintfEmpty-12          48.3ns ± 2%    47.6ns ± 1%  -1.52%  (p=0.000 n=20+16)
FmtFprintfString-12          152ns ± 0%     152ns ± 1%    ~     (p=0.725 n=18+18)
FmtFprintfInt-12             150ns ± 1%     149ns ± 1%  -1.14%  (p=0.000 n=19+20)
FmtFprintfIntInt-12          250ns ± 0%     244ns ± 1%  -2.12%  (p=0.000 n=20+18)
FmtFprintfPrefixedInt-12     219ns ± 1%     217ns ± 1%  -1.20%  (p=0.000 n=19+20)
FmtFprintfFloat-12           280ns ± 0%     281ns ± 1%  +0.47%  (p=0.000 n=19+19)
FmtManyArgs-12               928ns ± 0%     923ns ± 1%  -0.53%  (p=0.000 n=19+18)
GobDecode-12                7.21ms ± 1%    7.24ms ± 2%    ~     (p=0.091 n=19+19)
GobEncode-12                6.07ms ± 1%    6.05ms ± 1%  -0.36%  (p=0.002 n=20+17)
Gzip-12                      265ms ± 1%     265ms ± 1%    ~     (p=0.496 n=20+19)
Gunzip-12                   39.6ms ± 1%    39.3ms ± 1%  -0.85%  (p=0.000 n=19+19)
HTTPClientServer-12         74.0µs ± 2%    73.8µs ± 1%    ~     (p=0.569 n=20+19)
JSONEncode-12               15.4ms ± 1%    15.3ms ± 1%  -0.25%  (p=0.049 n=17+17)
JSONDecode-12               53.7ms ± 2%    53.0ms ± 1%  -1.29%  (p=0.000 n=18+17)
Mandelbrot200-12            3.97ms ± 1%    3.97ms ± 0%    ~     (p=0.072 n=17+18)
GoParse-12                  3.35ms ± 2%    3.36ms ± 1%  +0.51%  (p=0.005 n=18+20)
RegexpMatchEasy0_32-12      72.7ns ± 2%    72.2ns ± 1%  -0.70%  (p=0.005 n=19+19)
RegexpMatchEasy0_1K-12       246ns ± 1%     245ns ± 0%  -0.60%  (p=0.000 n=18+16)
RegexpMatchEasy1_32-12      72.8ns ± 1%    72.5ns ± 1%  -0.37%  (p=0.011 n=18+18)
RegexpMatchEasy1_1K-12       380ns ± 1%     385ns ± 1%  +1.34%  (p=0.000 n=20+19)
RegexpMatchMedium_32-12      115ns ± 2%     115ns ± 1%  +0.44%  (p=0.047 n=20+20)
RegexpMatchMedium_1K-12     35.4µs ± 1%    35.5µs ± 1%    ~     (p=0.079 n=18+19)
RegexpMatchHard_32-12       1.83µs ± 0%    1.80µs ± 1%  -1.76%  (p=0.000 n=18+18)
RegexpMatchHard_1K-12       55.1µs ± 0%    54.3µs ± 1%  -1.42%  (p=0.000 n=18+19)
Revcomp-12                   386ms ± 1%     381ms ± 1%  -1.14%  (p=0.000 n=18+18)
Template-12                 61.5ms ± 2%    61.5ms ± 2%    ~     (p=0.647 n=19+20)
TimeParse-12                 338ns ± 0%     336ns ± 1%  -0.72%  (p=0.000 n=14+19)
TimeFormat-12                350ns ± 0%     357ns ± 0%  +2.05%  (p=0.000 n=19+18)
[Geo mean]                  55.3µs         55.0µs       -0.41%

Change-Id: I57e8720385a1b991aeebd111b6874354308e2a6b
Reviewed-on: https://go-review.googlesource.com/20829
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-04-27 18:48:16 +00:00
Zhongwei Yao
74a9bad638 cmd/compile: enable const division for arm64
performance:
benchmark                   old ns/op     new ns/op     delta
BenchmarkDivconstI64-8      8.28          2.70          -67.39%
BenchmarkDivconstU64-8      8.28          4.69          -43.36%
BenchmarkDivconstI32-8      8.28          6.39          -22.83%
BenchmarkDivconstU32-8      8.28          4.43          -46.50%
BenchmarkDivconstI16-8      5.17          5.17          +0.00%
BenchmarkDivconstU16-8      5.33          5.34          +0.19%
BenchmarkDivconstI8-8       3.50          3.50          +0.00%
BenchmarkDivconstU8-8       3.51          3.50          -0.28%

Fixes #15382

Change-Id: Ibce7b28f0586d593b33c4d4ecc5d5e7e7c905d13
Reviewed-on: https://go-review.googlesource.com/22292
Reviewed-by: Michael Munday <munday@ca.ibm.com>
Reviewed-by: David Chase <drchase@google.com>
2016-04-27 17:47:49 +00:00
Matthew Dempsky
e48a2958d1 cmd/compile: treat empty and absent struct field tags as identical
Fixes #15439.

Change-Id: I5a32384c46e20f8db6968e5a9e854c45ab262fe4
Reviewed-on: https://go-review.googlesource.com/22429
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-25 21:28:45 +00:00
Alexandru Moșoi
8b92397bcd cmd/compile: introduce bool operations.
Introduce OrB, EqB, NeqB, AndB to handle bool operations.

Change-Id: I53e4d5125a8090d5eeb4576db619103f19fff58d
Reviewed-on: https://go-review.googlesource.com/22412
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-25 20:43:04 +00:00
Josh Bleecher Snyder
9dcbc43f4f test: add test for issue 15084
The underlying issues have been fixed.
All the individual fixes have their own tests,
but it's still useful to have a plain source test.

Fixes #15084

Change-Id: I06c485a7d0716201bd57d1f3be53668dddd7ec14
Reviewed-on: https://go-review.googlesource.com/22426
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-04-25 19:20:40 +00:00
Josh Bleecher Snyder
3de87bc4d9 test: add test that required algs get generated
This is a follow-up to CLs 19769 and 19770.

Change-Id: Ia9b71055613b80df4ce62b34fcc4f479f04f72fd
Reviewed-on: https://go-review.googlesource.com/22399
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-04-24 21:36:52 +00:00
Keith Randall
934c359964 cmd/compile: reorder how slicelit initializes a slice
func f(x, y, z *int) {
    a := []*int{x,y,z}
    ...
  }

We used to use:
  var tmp [3]*int
  a := tmp[:]
  a[0] = x
  a[1] = y
  a[2] = z

Now we do:
  var tmp [3]*int
  tmp[0] = x
  tmp[1] = y
  tmp[2] = z
  a := tmp[:]

Doesn't sound like a big deal, but the compiler has trouble
eliminating write barriers when using the former method because it
doesn't know that the slice points to the stack.  In the latter
method, the compiler knows the array is on the stack and as a result
doesn't emit any write barriers.

This turns out to be extremely common when building ... args, like
for calls fmt.Printf.

Makes go binaries ~1% smaller.

Doesn't have a measurable effect on the go1 fmt benchmarks,
unfortunately.

Fixes #14263
Update #6853

Change-Id: I9074a2788ec9e561a75f3b71c119b69f304d6ba2
Reviewed-on: https://go-review.googlesource.com/22395
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-24 18:15:41 +00:00
Alexandru Moșoi
caef4496fc cmd/compile: convert some Phis into And8.
See discussion at [1]. True value must have a fixed non-zero
representation meaning that a && b can be implemented as a & b.

[1] https://groups.google.com/forum/#!topic/golang-dev/xV0vPuFP9Vg

This change helps with m := a && b, but it's more common to see
if a && b { do something } which is not handled.

Change-Id: Ib6f9ff898a0a8c05d12466e2464e4fe781035394
Reviewed-on: https://go-review.googlesource.com/22313
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-22 17:22:03 +00:00
Keith Randall
3c1a4c1902 cmd/compile: don't nilcheck newobject and return values from mapaccess{1,2}
They are guaranteed to be non-nil, no point in inserting
nil checks for them.

Fixes #15390

Change-Id: I3b9a0f2319affc2139dcc446d0a56c6785ae5a86
Reviewed-on: https://go-review.googlesource.com/22291
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-22 16:18:42 +00:00
Tal Shprecher
75b886ab79 cmd/compile: reject embedded unsafe.Pointer values
Fixes #14729

Change-Id: Ied819aa7b23e25de30aa8cde049c97297b4cab11
Reviewed-on: https://go-review.googlesource.com/22325
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 00:32:01 +00:00
David Crawshaw
7acb642e4f test: print output on link -X failure
(Split out from CL 22205.)

Change-Id: Iab66ac2a1cd3716966d8e59c570931bce95aba9b
Reviewed-on: https://go-review.googlesource.com/22297
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-20 17:37:35 +00:00
Alexandru Moșoi
8b20fd000d cmd/compile: transform some Phis into Or8.
func f(a, b bool) bool {
          return a || b
}

is now a single instructions (excluding loading and unloading the arguments):
      v10 = ORB <bool> v11 v12 : AX

Change-Id: Iff63399410cb46909f4318ea1c3f45a029f4aa5e
Reviewed-on: https://go-review.googlesource.com/21872
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-19 22:04:30 +00:00
Ian Lance Taylor
f5423a63df cmd/compile: a dot expression can not be a struct literal key
Passes toolstash -cmp.

Fixes #15311.

Change-Id: I1d67f5c9de38e899ab2d6c8986fabd6f197df23a
Reviewed-on: https://go-review.googlesource.com/22162
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-04-18 15:09:47 +00:00
Keith Randall
ac8127d7e6 cmd/compile: fix register size for ODOTPTR result
The result of ODOTPTR, as well as a bunch of other ops,
should be the type of the result, not always a pointer type.

This fixes an amd64p32 bug where we were incorrectly truncating
a 64-bit slice index to 32 bits, and then barfing on a weird
load-64-bits-but-then-truncate-to-32-bits op that doesn't exist.

Fixes #15252

Change-Id: Ie62f4315fffd79f233e5449324ccc0879f5ac343
Reviewed-on: https://go-review.googlesource.com/22094
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-14 21:19:12 +00:00
Josh Bleecher Snyder
644493f109 cmd/compile: clear hidden value at end of channel range body
While we’re here, clean up a few comments.

Fixes #15281

Change-Id: Ia6173e9941133db08f57bc80bdd3c5722122bfdb
Reviewed-on: https://go-review.googlesource.com/22082
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-04-14 19:20:26 +00:00
Michael Munday
24bd465bca test: use correct value in error message in init1.go
Print numGC followed by numGC1, rather than printing numGC twice.

Change-Id: I8e7144b6a11d4ae9be0d82d88b86fed04b906e2f
Reviewed-on: https://go-review.googlesource.com/22087
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-14 18:35:09 +00:00
Tal Shprecher
24967ec122 cmd/compile: make enqueued map keys fail validation on forward types
Map keys are currently validated in multiple locations but share
a common validation routine. The problem is that early validations
should be lenient enough to allow for forward types while the final
validations should not. The final validations should fail on forward
types since they've already settled.

This change also separates the key type checking from the creation
of the map via typMap. Instead of the mapqueue being populated in
copytype() by checking the map line number, it's populated in the
same block that validates the key type. This isolates key validation
logic while type checking.

Fixes #14988

Change-Id: Ia47cf6213585d6c63b3a35249104c0439feae658
Reviewed-on: https://go-review.googlesource.com/21830
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-13 08:43:12 +00:00
Matthew Dempsky
0e01db4b8d cmd/compile: fix crash on bare package name in constant declarations
Fixes #11361.

Change-Id: I70b8808f97f0e07de680e7e6ede1322ea0fdbbc0
Reviewed-on: https://go-review.googlesource.com/21936
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-13 06:37:39 +00:00
Alexandru Moșoi
6c6089b3fd cmd/compile: bce when max and limit are consts
Removes 49 more bound checks in make.bash. For example:

var a[100]int
for i := 0; i < 50; i++ {
  use a[i+25]
}

Change-Id: I85e0130ee5d07f0ece9b17044bba1a2047414ce7
Reviewed-on: https://go-review.googlesource.com/21379
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-11 16:01:22 +00:00
David Chase
c3b3e7b4ef cmd/compile: insert instrumentation more carefully in racewalk
Be more careful about inserting instrumentation in racewalk.
If the node being instrumented is an OAS, and it has a non-
empty Ninit, then append instrumentation to the Ninit list
rather than letting it be inserted before the OAS (and the
compilation of its init list).  This deals with the case that
the Ninit list defines a variable used in the RHS of the OAS.

Fixes #15091.

Change-Id: Iac91696d9104d07f0bf1bd3499bbf56b2e1ef073
Reviewed-on: https://go-review.googlesource.com/21771
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: David Chase <drchase@google.com>
2016-04-08 21:06:39 +00:00
Michael Munday
dae98d5c3b test: skip nilptr3 test on s390x
Fails for the same reason as ppc64 and mips64 (incomplete
optimization).

Change-Id: Ieb4d997fc27d4f2b756e63dd7f588abe10c0213a
Reviewed-on: https://go-review.googlesource.com/20963
Reviewed-by: Bill O'Farrell <billotosyr@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-08 17:51:46 +00:00
Keith Randall
68ac1f7746 cmd/compile: Fix constant-folding of unsigned shifts
Make sure the results of unsigned constant-folded
shifts are sign-extended into the AuxInt field.

Fixes #15175

Change-Id: I3490d1bc3d9b2e1578ed30964645508577894f58
Reviewed-on: https://go-review.googlesource.com/21586
Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-07 21:39:32 +00:00
Alexandru Moșoi
8448d3aace cmd/compile: fold CMPconst and SHR
Fold the comparison when the SHR result is small.

Useful for:
- murmur mix like hashing where higher bits are desirable, i.e. hash = uint32(i * C) >> 18
- integer log2 via DeBruijn sequence: http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogDeBruijn

Change-Id: If70ae18cb86f4cc83ab6213f88ced03cc4986156
Reviewed-on: https://go-review.googlesource.com/21514
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-04-07 13:28:13 +00:00
Richard Miller
a25e368f44 test: make goprint.go wait for goroutine termination
Test goprint.go sometimes failed on a slow builder (plan9_arm)
because of timing dependency.  Instead of sleeping for a fixed
time to allow the child goroutine to finish, wait explicitly for
child termination by calling runtime.NumGoroutine until the
returned value is 1.

Fixes #15097

Change-Id: Ib3ef5ec3c8277083c774542f48bcd4ff2f79efde
Reviewed-on: https://go-review.googlesource.com/21603
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-06 18:45:00 +00:00
Keith Randall
309144b7f1 cmd/compile: fix x=x assignments
No point in doing anything for x=x assignments.
In addition, skipping these assignments prevents generating:
    VARDEF x
    COPY x -> x
which is bad because x is incorrectly considered
dead before the vardef.

Fixes #14904

Change-Id: I6817055ec20bcc34a9648617e0439505ee355f82
Reviewed-on: https://go-review.googlesource.com/21470
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
2016-04-06 15:04:32 +00:00
David Chase
d8c815d8b5 cmd/compile: note escape of parts of closured-capture vars
Missed a case for closure calls (OCALLFUNC && indirect) in
esc.go:esccall.

Cleanup to runtime code for windows to more thoroughly hide
a technical escape.  Also made code pickier about failing
to late non-optional kernel32.dll.

Fixes #14409.

Change-Id: Ie75486a2c8626c4583224e02e4872c2875f7bca5
Reviewed-on: https://go-review.googlesource.com/20102
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 18:10:09 +00:00
Alexandru Moșoi
1747788c56 cmd/compile: add a pass to print bound checks
Since BCE happens over several passes (opt, loopbce, prove)
it's easy to regress especially with rewriting.

The pass is only activated with special debug flag.

Change-Id: I46205982e7a2751156db8e875d69af6138068f59
Reviewed-on: https://go-review.googlesource.com/21510
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-04-05 12:46:59 +00:00
Caio Marcelo de Oliveira Filho
f229e46783 cmd/compile: better error when assigning to struct field in map
Identify this assignment case and instead of the more general error

    prog.go:6: cannot assign to students["sally"].age

produce

    prog.go:6: cannot directly assign to struct field students["sally"].age in map

that explains why the assignment is not possible.

Fixes #13779.

Change-Id: I90c10b445f907834fc1735aa66e44a0f447aa74f
Reviewed-on: https://go-review.googlesource.com/21462
Reviewed-by: David Chase <drchase@google.com>
2016-04-04 14:07:47 +00:00
Eric Engestrom
7a8caf7d43 all: fix spelling mistakes
Signed-off-by: Eric Engestrom <eric@engestrom.ch>

Change-Id: I91873aaebf79bdf1c00d38aacc1a1fb8d79656a7
Reviewed-on: https://go-review.googlesource.com/21433
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-03 17:03:15 +00:00
Alexandru Moșoi
27ebc84716 cmd/compile: handle non-negatives in prove
Handle this case:
if 0 <= i && i < len(a) {
        use a[i]
}

Shaves about 5k from pkg/tools/linux_amd64/*.

Change-Id: I6675ff49aa306b0d241b074c5738e448204cd981
Reviewed-on: https://go-review.googlesource.com/21431
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-02 20:34:38 +00:00
Todd Neal
ac8d97b679 cmd/compile: fix inlining of switch issue
The issue was seen when inlining an exported function that contained
a fallthrough statement.

Fixes #15071

Change-Id: I1e8215ad49d57673dba7e8f8bd2ed8ad290dc452
Reviewed-on: https://go-review.googlesource.com/21452
Reviewed-by: Dave Cheney <dave@cheney.net>
2016-04-02 12:38:00 +00:00
Alexandru Moșoi
b91cc53033 cmd/compile/internal/ssa: BCE for induction variables
There are 5293 loop in the main go repository.
A survey of the top most common for loops:

     18 for __k__ := 0; i < len(sa.Addr); i++ {
     19 for __k__ := 0; ; i++ {
     19 for __k__ := 0; i < 16; i++ {
     25 for __k__ := 0; i < length; i++ {
     30 for __k__ := 0; i < 8; i++ {
     49 for __k__ := 0; i < len(s); i++ {
     67 for __k__ := 0; i < n; i++ {
    376 for __k__ := range __slice__ {
    685 for __k__, __v__ := range __slice__ {
   2074 for __, __v__ := range __slice__ {

The algorithm to find induction variables handles all cases
with an upper limit. It currently doesn't find related induction
variables such as c * ind or c + ind.

842 out of 22954 bound checks are removed for src/make.bash.
1957 out of 42952 bounds checks are removed for src/all.bash.

Things to do in follow-up CLs:
* Find the associated pointer for `for _, v := range a {}`
* Drop the NilChecks on the pointer.
* Replace the implicit induction variable by a loop over the pointer

Generated garbage can be reduced if we share the sdom between passes.

% benchstat old.txt new.txt
name       old time/op     new time/op     delta
Template       337ms ± 3%      333ms ± 3%    ~             (p=0.258 n=9+9)
GoTypes        1.11s ± 2%      1.10s ± 2%    ~           (p=0.912 n=10+10)
Compiler       5.25s ± 1%      5.29s ± 2%    ~             (p=0.077 n=9+9)
MakeBash       33.5s ± 1%      34.1s ± 2%  +1.85%          (p=0.011 n=9+9)

name       old alloc/op    new alloc/op    delta
Template      63.6MB ± 0%     63.9MB ± 0%  +0.52%         (p=0.000 n=10+9)
GoTypes        218MB ± 0%      219MB ± 0%  +0.59%         (p=0.000 n=10+9)
Compiler       978MB ± 0%      985MB ± 0%  +0.69%        (p=0.000 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        582k ± 0%       583k ± 0%  +0.10%        (p=0.000 n=10+10)
GoTypes        1.78M ± 0%      1.78M ± 0%  +0.12%        (p=0.000 n=10+10)
Compiler       7.68M ± 0%      7.69M ± 0%  +0.05%        (p=0.000 n=10+10)

name       old text-bytes  new text-bytes  delta
HelloSize       581k ± 0%       581k ± 0%  -0.08%        (p=0.000 n=10+10)
CmdGoSize      6.40M ± 0%      6.39M ± 0%  -0.08%        (p=0.000 n=10+10)

name       old data-bytes  new data-bytes  delta
HelloSize      3.66k ± 0%      3.66k ± 0%    ~     (all samples are equal)
CmdGoSize       134k ± 0%       134k ± 0%    ~     (all samples are equal)

name       old bss-bytes   new bss-bytes   delta
HelloSize       126k ± 0%       126k ± 0%    ~     (all samples are equal)
CmdGoSize       149k ± 0%       149k ± 0%    ~     (all samples are equal)

name       old exe-bytes   new exe-bytes   delta
HelloSize       947k ± 0%       946k ± 0%  -0.01%        (p=0.000 n=10+10)
CmdGoSize      9.92M ± 0%      9.91M ± 0%  -0.06%        (p=0.000 n=10+10)

Change-Id: Ie74bdff46fd602db41bb457333d3a762a0c3dc4d
Reviewed-on: https://go-review.googlesource.com/20517
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
2016-04-01 09:37:58 +00:00
David Chase
b64f549ba9 cmd/compile: ignore OXXX nodes in closure captured vars list
Added a debug flag "-d closure" to explain compilation of
closures (should this be done some other way? Should we
rewrite the "-m" flag to "-d escapes"?)  Used this to
discover that cause was an OXXX node in the captured vars
list, and in turn noticed that OXXX nodes are explicitly
ignored in all other processing of captured variables.

Couldn't figure out a reproducer, did verify that this OXXX
was not caused by an unnamed return value (which is one use
of these).  Verified lack of heap allocation by examining -S
output.

Assembly:
(runtime/mgc.go:1371) PCDATA $0, $2
(runtime/mgc.go:1371) CALL "".notewakeup(SB)
(runtime/mgc.go:1377) LEAQ "".gcBgMarkWorker.func1·f(SB), AX
(runtime/mgc.go:1404) MOVQ AX, (SP)
(runtime/mgc.go:1404) MOVQ "".autotmp_2242+88(SP), CX
(runtime/mgc.go:1404) MOVQ CX, 8(SP)
(runtime/mgc.go:1404) LEAQ go.string."GC worker (idle)"(SB), AX
(runtime/mgc.go:1404) MOVQ AX, 16(SP)
(runtime/mgc.go:1404) MOVQ $16, 24(SP)
(runtime/mgc.go:1404) MOVB $20, 32(SP)
(runtime/mgc.go:1404) MOVQ $0, 40(SP)
(runtime/mgc.go:1404) PCDATA $0, $2
(runtime/mgc.go:1404) CALL "".gopark(SB)

Added a check for compiling_runtime to ensure that this is
caught in the future.  Added a test to test the check.
Verified that 1.5.3 did NOT reject the test case when
compiled with -+ flag, so this is not a recently added bug.

Cause of bug is two-part -- there was no leaking closure
detection ever, and instead it relied on capture-of-variables
to trigger compiling_runtime test, but closures improved in
1.5.3 so that mere capture of a value did not also capture
the variable, which thus allowed closures to escape, as well
as this case where the escape was spurious.  In
fixedbugs/issue14999.go, compare messages for f and g;
1.5.3 would reject g, but not f.  1.4 rejects both because
1.4 heap-allocates parameter x for both.

Fixes #14999.

Change-Id: I40bcdd27056810628e96763a44f2acddd503aee1
Reviewed-on: https://go-review.googlesource.com/21322
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-01 02:08:56 +00:00
Ian Lance Taylor
92bb694a49 cmd/compile: s.f aliases itself
The change in 20907 fixed varexpr but broke aliased.  After that change,
a reference to a field in a struct would not be seen as aliasing itself.
Before that change, it would, but only because all fields in a struct
aliased everything.

This CL changes the compiler to consider all references to a field as
aliasing all other fields in that struct.  This is imperfect--a
reference to one field does not alias another field--but is a simple fix
for the immediate problem.  A better fix would require tracking the
specific fields as well.

Fixes #15042.

Change-Id: I5c95c0dd7b0699e53022fce9bae2e8f50d6d1d04
Reviewed-on: https://go-review.googlesource.com/21390
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-04-01 00:47:56 +00:00
Keith Randall
4a7aba775d cmd/compile: better job of naming compound types
Compound AUTO types weren't named previously.  That was because live
variable analysis (plive.go) doesn't handle spilling to compound types.
It can't handle them because there is no valid place to put VARDEFs when
regalloc is spilling compound types.

compound types = multiword builtin types: complex, string, slice, and
interface.

Instead, we split named AUTOs into individual one-word variables.  For
example, a string s gets split into a byte ptr s.ptr and an integer
s.len.  Those two variables can be spilled to / restored from
independently.  As a result, live variable analysis can handle them
because they are one-word objects.

This CL will change how AUTOs are described in DWARF information.
Consider the code:

func f(s string, i int) int {
    x := s[i:i+5]
    g()
    return lookup(x)
}

The old compiler would spill x to two consecutive slots on the stack,
both named x (at offsets 0 and 8).  The new compiler spills the pointer
of x to a slot named x.ptr.  It doesn't spill x.len at all, as it is a
constant (5) and can be rematerialized for the call to lookup.

So compound objects may not be spilled in their entirety, and even if
they are they won't necessarily be contiguous.  Such is the price of
optimization.

Re-enable live variable analysis tests.  One test remains disabled, it
fails because of #14904.

Change-Id: I8ef2b5ab91e43a0d2136bfc231c05d100ec0b801
Reviewed-on: https://go-review.googlesource.com/21233
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-03-31 22:18:26 +00:00
Keith Randall
47c9e139ae cmd/compile: extend prove pass to handle constant comparisons
Find comparisons to constants and propagate that information
down the dominator tree.  Use it to resolve other constant
comparisons on the same variable.

So if we know x >= 7, then a x > 4 condition must return true.

This change allows us to use "_ = b[7]" hints to eliminate bounds checks.

Fixes #14900

Change-Id: Idbf230bd5b7da43de3ecb48706e21cf01bf812f7
Reviewed-on: https://go-review.googlesource.com/21008
Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
2016-03-31 21:16:23 +00:00
Keith Randall
4b95575bd4 cmd/compile: fix build
Pushed from an old client by mistake.  These are the
missing changes.

Change-Id: Ia8d61c5c0bde907369366ea9ea98711823342803
Reviewed-on: https://go-review.googlesource.com/21349
Reviewed-by: Todd Neal <todd@tneal.org>
2016-03-31 18:00:36 +00:00
Keith Randall
b81f2f106f cmd/compile: place combined loads at the location of the last byte load
We need to make sure all the bounds checks pass before issuing
a load which combines several others.  We do this by issuing the
combined load at the last load's block, where "last" = closest to
the leaf of the dominator tree.

Fixes #15002

Change-Id: I7358116db1e039a072c12c0a73d861f3815d72af
Reviewed-on: https://go-review.googlesource.com/21246
Reviewed-by: Todd Neal <todd@tneal.org>
2016-03-31 17:21:33 +00:00
Matthew Dempsky
e6066711a0 cmd/compile, runtime: fix pedantic int->string conversions
Previously, cmd/compile rejected constant int->string conversions if
the integer value did not fit into an "int" value. Also, runtime
incorrectly truncated 64-bit values to 32-bit before checking if
they're a valid Unicode code point. According to the Go spec, both of
these cases should instead yield "\uFFFD".

Fixes #15039.

Change-Id: I3c8a3ad9a0780c0a8dc1911386a523800fec9764
Reviewed-on: https://go-review.googlesource.com/21344
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-31 10:28:23 +00:00
Brad Fitzpatrick
758447cdc9 test/fixedbugs: add test for divide by zero being optimized away
This only tests amd64 because it's currently broken on non-SSA
backends.

Fixes #8613

Change-Id: I6bc501c81c395e533bb9c7335789750e0c6b7a8f
Reviewed-on: https://go-review.googlesource.com/21325
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-31 06:12:38 +00:00
Alexandru Moșoi
d8f1f8d856 cmd/compile: generalize strength reduction of mulq
* This is an improved version of an earlier patch.
* Verified with gcc up to 100.
* Limited to two instructions based on costs from
https://gmplib.org/~tege/x86-timing.pdf

Change-Id: Ib7c37de6fd8e0ba554459b15c7409508cbcf6728
Reviewed-on: https://go-review.googlesource.com/21103
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-30 22:27:13 +00:00
Ian Lance Taylor
777a77b4d2 cmd/compile: don't skip PPARAMOUT in esccall after varargs
Fixes bug I introduced in CL 21202.

Fixes #15013.

Change-Id: I2344d7e22b8273425a0a56f4a77588b5c6e4d8c6
Reviewed-on: https://go-review.googlesource.com/21270
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-30 02:43:08 +00:00
David Chase
8eec2bbfbc cmd/compile: added some intrinsics to SSA back end
One intrinsic was needed to help get the very best
performance out of a future GC; as long as that one was
being added, I also added Bswap since that is sometimes
a handy thing to have.  I had intended to fill out the
bit-scan intrinsic family, but the mismatch between the
"scan forward" instruction and "count leading zeroes"
was large enough to cause me to leave it out -- it poses
a dilemma that I'd rather dodge right now.

These intrinsics are not exposed for general use.
That's a separate issue requiring an API proposal change
( https://github.com/golang/proposal )

All intrinsics are tested, both that they are substituted
on the appropriate architecture, and that they produce the
expected result.

Change-Id: I5848037cfd97de4f75bdc33bdd89bba00af4a8ee
Reviewed-on: https://go-review.googlesource.com/20564
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-28 16:29:59 +00:00
Robert Griesemer
c12e1b0b2e cmd/compile: update vendored math/big to latest version
This makes the rounding bug fix in math/big for issue 14651 available
to the compiler.

- changes to cmd/compile/internal/big fully automatic via script
- added test case for issue
- updated old test case with correct test data

Fixes #14651.

Change-Id: Iea37a2cd8d3a75f8c96193748b66156a987bbe40
Reviewed-on: https://go-review.googlesource.com/20818
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-22 17:09:29 +00:00
Keith Randall
d4663e1353 cmd/compile: don't write back unchanged slice results
Don't write back parts of a slicing operation if they
are unchanged from the source of the slice.  For example:

x.s = x.s[0:5]         // don't write back pointer or cap
x.s = x.s[:5]          // don't write back pointer or cap
x.s = x.s[:5:7]        // don't write back pointer

There is more to be done here, for example:

x.s = x.s[:len(x.s):7] // don't write back ptr or len

This CL can't handle that one yet.

Fixes #14855

Change-Id: Id1e1a4fa7f3076dc1a76924a7f1cd791b81909bb
Reviewed-on: https://go-review.googlesource.com/20954
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
2016-03-21 23:40:18 +00:00
Todd Neal
e41f527f4d cmd/compile: allow inlining of functions with switch statements
Allow inlining of functions with switch statements as long as they don't
contain a break or type switch.

Fixes #13071

Change-Id: I057be351ea4584def1a744ee87eafa5df47a7f6d
Reviewed-on: https://go-review.googlesource.com/20824
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-21 23:05:10 +00:00
Michael Munday
4402ee9fa3 test: add s390x case to nosplit test
Fixes this test on s390x.

Change-Id: Ie5b70e8191169867765ec9248d827ca12c6405f4
Reviewed-on: https://go-review.googlesource.com/20964
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-21 08:14:51 +00:00
Michael Munday
1a82946ea5 test/fixedbugs: add s390x case to issue11656
An instruction consisting of all 0s causes an illegal instruction
signal on s390x. Since 0s are the default in this test this CL just
makes it explicit.

Change-Id: Id6e060eed1a588f4b10a4e4861709fcd19b434ac
Reviewed-on: https://go-review.googlesource.com/20962
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-21 07:09:36 +00:00
Todd Neal
fc6bcdee79 cmd/compile: allow inlining of functions that declare a const
Consider functions with an ODCLCONST for inlining and modify exprfmt to
ignore those nodes when exporting. Don't add symbols to the export list
if there is no definition.  This occurs when OLITERAL symbols are looked
up via Pkglookup for non-exported symbols.

Fixes #7655

Change-Id: I1de827850f4c69e58107447314fe7433e378e069
Reviewed-on: https://go-review.googlesource.com/20773
Run-TryBot: Todd Neal <todd@tneal.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-03-18 23:26:36 +00:00
Marcel van Lohuizen
5c83e651ad testing: prepare for the introduction of Run methods
The biggest change is that each test is now responsible for managing
the starting and stopping of its parallel subtests.

The "Main" test could be run as a tRunner as well. This shows that
the introduction of subtests is merely a generalization of and
consistent with the current semantics.

Change-Id: Ibf8388c08f85d4b2c0df69c069326762ed36a72e
Reviewed-on: https://go-review.googlesource.com/18893
Reviewed-by: Russ Cox <rsc@golang.org>
2016-03-18 11:25:54 +00:00
Keith Randall
15ed37d7b7 cmd/compile: enforce nowritebarrier in SSA compiler
Make sure we don't generate write barriers in runtime
code that is marked to forbid write barriers.

Implement the optimization that if we're writing a sliced
slice back to the location it came from, we don't need a
write barrier.

Fixes #14784

Change-Id: I04b6a3b2ac303c19817e932a36a3b006de103aaa
Reviewed-on: https://go-review.googlesource.com/20791
Reviewed-by: Austin Clements <austin@google.com>
2016-03-17 20:13:24 +00:00
David Chase
2d56dee61b cmd/compile: escape analysis explanations added to -m -m output
This should probably be considered "experimental" at this stage, but
what it needs is feedback from adventurous adopters.  I think the data
structure used for describing escape reasons might be extendable to
allow a cleanup of the underlying algorithms, which suffers from
insufficiently separated concerns (the graph does not deal well with
escape level adjustments, so it is augmented by a second custom-walk
portion of the "flood" phase. It would be better to put it all,
including level adjustments, in a single graph structure, and then
simply flood the graph.

Tweaked to avoid allocations in the no-logging case.

Modified run.go to ignore lines with leading "#" in the output (since
it can never match a line), and in -update_errors to ignore leading
tabs in output lines and to normalize embedded filenames.

Currently requires -m -m because otherwise the noise/update
burden for the other escape tests is considerable.

There is a partial test.  Existing escape analysis tests seem to
cover all except the panic case and what looks like it might be
unreachable code in escape analysis.

Fixes #10526.

Change-Id: I2524fdec54facae48b00b2548e25d9e46fcaf832
Reviewed-on: https://go-review.googlesource.com/18041
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-17 13:29:48 +00:00
Keith Randall
56e0ecc5ea cmd/compile: keep value use counts in SSA
Keep track of how many uses each Value has.  Each appearance in
Value.Args and in Block.Control counts once.

The number of uses of a value is generically useful to
constrain rewrite rules.  For instance, we might want to
prevent merging index operations into loads if the same
index expression is used lots of times.

But I have one use in particular for which the use count is required.
We must make sure we don't combine ops with loads if the load has
more than one use.  Otherwise, we may split a single load
into multiple loads and that breaks perceived behavior in
the presence of races.  In particular, the load of m.state
in sync/mutex.go:Lock can't be done twice.  (I have a separate
CL which triggers the mutex failure.  This CL has a test which
demonstrates a similar failure.)

Change-Id: Icaafa479239f48632a069d0c3f624e6ebc6b1f0e
Reviewed-on: https://go-review.googlesource.com/20790
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>
2016-03-17 04:20:02 +00:00
Matthew Dempsky
b2b5e779f5 cmd/compile: ignore receiver parameters in Eqtype
Receiver parameters generally aren't relevant to the function
signature type. In particular:

  1. When checking whether a type's method implements an interface's
     method, we specifically want to ignore the receiver parameters,
     because they'll be different.

  2. When checking interface type equality, interface methods always
     use the same "fakethis" *struct{} type as their receiver.

  3. Finally, method expressions and method values degenerate into
     receiver-less function types.

The only case where we care about receiver types matching is in
addmethod, which is easily handled by adding an extra Eqtype check of
the receiver parameters. Also, added a test for this, since
(surprisingly) there weren't any.

As precedence, go/types.Identical ignores receiver parameters when
comparing go/types.Signature values.

Notably, this allows us to slightly simplify the "implements"
function, which is used for checking whether type/interface t
implements interface iface. Currently, cmd/compile actually works
around Eqtype's receiver parameter checking by creating new throwaway
TFUNC Types without the receiver parameter.

(Worse, the compiler currently only provides APIs to build TFUNC Types
from Nod syntax trees, so building those throwaway types also involves
first building throwaway syntax trees.)

Passes toolstash -cmp.

Change-Id: Ib07289c66feacee284e016bc312e8c5ff674714f
Reviewed-on: https://go-review.googlesource.com/20602
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-03-17 00:38:15 +00:00
Austin Clements
3e54ca9a46 cmd/compile: omit write barrier when assigning global function
Currently we generate write barriers when the right side of an
assignment is a global function. This doesn't fall into the existing
case of storing an address of a global because we haven't lowered the
function to a pointer yet.

This write barrier is unnecessary, so eliminate it.

Fixes #13901.

Change-Id: Ibc10e00a8803db0fd75224b66ab94c3737842a79
Reviewed-on: https://go-review.googlesource.com/20772
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2016-03-16 22:42:45 +00:00
Robert Griesemer
bb3b10214d cmd/compile: faster parameter parsing with no OKEY nodes
Step 2 of stream-lining parameter parsing

- do parameter validity checks in parser
- two passes instead of multiple (and theoretically quadratic) passes
  when checking parameters
- removes the need for OKEY and some ONONAME nodes in those passes

This removes allocation of ~123K OKEY (incl. some ONONAME) nodes
out of a total of ~10M allocated nodes when running make.bash, or
a reduction of the number of alloacted nodes by ~1.2%.

Change-Id: I4a8ec578d0ee2a7b99892ac6b92e56f8e0415f03
Reviewed-on: https://go-review.googlesource.com/20748
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
2016-03-16 18:54:31 +00:00
Alexandru Moșoi
cd798dcb88 cmd/compile/internal/ssa: generalize prove to all booleans
* Refacts a bit saving and restoring parents restrictions
* Shaves ~100k from pkg/tools/linux_amd64,
but most of the savings come from the rewrite rules.
* Improves on the following artificial test case:
func f1(a4 bool, a6 bool) bool {
  return a6 || (a6 || (a6 || a4)) || (a6 || (a4 || a6 || (false || a6)))
}

Change-Id: I714000f75a37a3a6617c6e6834c75bd23674215f
Reviewed-on: https://go-review.googlesource.com/20306
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-13 12:05:41 +00:00
David Crawshaw
e2836935bb cmd/link: treat reflect.Value.Method like Call
Fixes #14740

Change-Id: Iad8d971c21977b0a1f4ef55a08bb180a8125e976
Reviewed-on: https://go-review.googlesource.com/20562
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-11 22:07:02 +00:00
David Crawshaw
5aa5db7593 cmd/compile: use bufio.Reader directly in lexer
Removes an intermediate layer of functions that was clogging up a
corner of the compiler's profile graph.

I can't measure a performance improvement running a large build
like jujud, but the profile reports less total time spent in
gc.(*lexer).getr.

Change-Id: I3000585cfcb0f9729d3a3859e9023690a6528591
Reviewed-on: https://go-review.googlesource.com/20565
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-11 21:27:23 +00:00
David Crawshaw
cc158403d6 cmd/compile: track reflect.Type.Method in deadcode
In addition to reflect.Value.Call, exported methods can be invoked
by the Func value in the reflect.Method struct. This CL has the
compiler track what functions get access to a legitimate reflect.Method
struct by looking for interface calls to either of:

	Method(int) reflect.Method
	MethodByName(string) (reflect.Method, bool)

This is a little overly conservative. If a user implements a type
with one of these methods without using the underlying calls on
reflect.Type, the linker will assume the worst and include all
exported methods. But it's cheap.

No change to any of the binary sizes reported in cl/20483.

For #14740

Change-Id: Ie17786395d0453ce0384d8b240ecb043b7726137
Reviewed-on: https://go-review.googlesource.com/20489
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-03-11 21:19:20 +00:00
Keith Randall
31d13f479a cmd/compile: don't use PPARAMOUT names for temps
The location of VARDEFs is incorrect for PPARAMOUT variables
which are also used as temporary locations.  We put in VARDEFs
when setting the variable at return time, but when the location
is also used as a temporary the lifetime values are wrong.

Fix copyelim to update the names map properly.  This is a
real name bug fix which, as a result, allows me to
write a reasonable test to trigger the PPARAMOUT bug.

This is kind of a band-aid fix for #14591.  A more pricipled
fix (which allows values to be stored in the return variable
earlier than the return point) will be harder.

Fixes #14591

Change-Id: I7df8ae103a982d1f218ed704c080d7b83cdcfdd9
Reviewed-on: https://go-review.googlesource.com/20457
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-03-11 00:56:04 +00:00
Keith Randall
ddc6b64444 cmd/compile: fix defer/deferreturn
Make sure we do any just-before-return cleanup on all paths out of a
function, including when recovering.  Each exit path should include
deferreturn (if there are any defers) and then the exit
code (e.g. copying heap-escaping return values back to the stack).

Introduce a Defer SSA block type which has two outgoing edges - one the
fallthrough edge (the defer was queued successfully) and one which
immediately returns (the defer had a successful recover() call and
normal execution should resume at the return point).

Fixes #14725

Change-Id: Iad035c9fd25ef8b7a74dafbd7461cf04833d981f
Reviewed-on: https://go-review.googlesource.com/20486
Reviewed-by: David Chase <drchase@google.com>
2016-03-10 22:33:49 +00:00
Matthew Dempsky
49dad0f571 cmd/compile: support arbitrarily deep embedded fields
Fixes #13337.

Change-Id: Ie74d00390111796619150287d3f7a147750ab456
Reviewed-on: https://go-review.googlesource.com/19932
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-10 06:33:52 +00:00
David Chase
4c8589c328 cmd/compile: attach correct line number for fallthru-return
Fixes #14646.

Change-Id: I0bb82ed6d3533633cd8369ba37aa467948bbe155
Reviewed-on: https://go-review.googlesource.com/20381
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-03-08 19:23:25 +00:00
Caio Marcelo de Oliveira Filho
c97ddf9c10 cmd/compile: don't emit conversion error in non-numeric increment/decrement
In increment and decrement statements, explicit check that the type
of operand is numeric earlier. This avoids a related but less clear
error about converting "1" to be emitted.

So, when compiling

	package main

	func main() {
		var x bool
		x++
	}

instead of emitting two errors

	prog.go:5: cannot convert 1 to type bool
	prog.go:5: invalid operation: x++ (non-numeric type bool)

just emits the second error.

Fixes #12525.

Change-Id: I6e81330703765bef0d6eb6c57098c1336af7c799
Reviewed-on: https://go-review.googlesource.com/20245
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-03-07 14:34:58 +00:00
Matthew Dempsky
3da1a26fba cmd/compile: stop leaking 'any' type into user package
The new check corresponds to the (etype != TANY || Debug['A'] != 0)
that was lost in golang.org/cl/19936.

Fixes #14652.

Change-Id: Iec3788ff02529b3b0f0d4dd92ec9f3ef20aec849
Reviewed-on: https://go-review.googlesource.com/20271
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-05 02:13:04 +00:00
Rhys Hiltner
3375974e0d cmd/link/internal/ld: don't panic on short buildid
When the linker was written in C, command line arguments were passed
around as null-terminated byte arrays which encouraged checking
characters one at a time. In Go, that can easily lead to
out-of-bounds panics.

Use the more idiomatic strings.HasPrefix when checking cmd/link's -B
argument to avoid the panic, and replace the manual hex decode with
use of the encoding/hex package.

Fixes #14636

Change-Id: I45f765bbd8cf796fee1a9a3496178bf76b117827
Reviewed-on: https://go-review.googlesource.com/20211
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-04 21:20:09 +00:00
Robert Griesemer
646939c0e3 cmd/compile: re-vendor math/big to pick up bug fix
The changes to internal/big are completely automatic
by running vendor.bash in that directory.

Also added respective test case.

For #14553.

Change-Id: I98b124bcc9ad9e9bd987943719be27864423cb5d
Reviewed-on: https://go-review.googlesource.com/20199
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-04 17:40:16 +00:00
Keith Randall
9d854fd44a Merge branch 'dev.ssa' into mergebranch
Merge dev.ssa branch back into master.

Change-Id: Ie6fac3f8d355ab164f934415fe4fc7fcb8c3db16
2016-03-01 12:50:17 -08:00
David Chase
6b3462c784 [dev.ssa] cmd/compile: adjust branch likeliness for calls/loops
Static branch predictions (which guide block ordering) are
adjusted based on:

loop/not-loop     (favor looping)
abnormal-exit/not (avoid panic)
call/not-call     (avoid call)
ret/default       (treat returns as rare)

This appears to make no difference in performance of real
code, meaning the compiler itself.  The earlier version of
this has been stripped down to help make the cost of this
only-aesthetic-on-Intel phase be as cheap as possible (we
probably want information about inner loops for improving
register allocation, but because register allocation follows
close behind this pass, conceivably the information could be
reused -- so we might do this anyway just to normalize
output).

For a ./make.bash that takes 200 user seconds, about .75
second is reported in likelyadjust (summing nanoseconds
reported with -d=ssa/likelyadjust/time ).

Upstream predictions are respected.
Includes test, limited to build on amd64 only.
Did several iterations on the debugging output to allow
some rough checks on behavior.
Debug=1 logging notes agree/disagree with earlier passes,
allowing analysis like the following:

Run on make.bash:
GO_GCFLAGS=-d=ssa/likelyadjust/debug \
   ./make.bash >& lkly5.log

grep 'ranch prediction' lkly5.log | wc -l
   78242 // 78k predictions

grep 'ranch predi' lkly5.log | egrep -v 'agrees with' | wc -l
   29633 // 29k NEW predictions

grep 'disagrees' lkly5.log | wc -l
     444 // contradicted 444 times

grep '< exit' lkly5.log | wc -l
   10212 // 10k exit predictions

grep '< exit' lkly5.log | egrep 'disagrees' | wc -l
       5 // 5 contradicted by previous prediction

grep '< exit' lkly5.log | egrep -v 'agrees' | wc -l
     702 // 702-5 redundant with previous prediction

grep '< call' lkly5.log | egrep -v 'agrees' | wc -l
   16699 // 16k new call predictions

grep 'stay in loop' lkly5.log | egrep -v 'agrees' | wc -l
    3951 // 4k new "remain in loop" predictions

Fixes #11451.

Change-Id: Iafb0504f7030d304ef4b6dc1aba9a5789151a593
Reviewed-on: https://go-review.googlesource.com/19995
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2016-03-01 20:09:41 +00:00
Alexandru Moșoi
e197f467d5 [dev.ssa] cmd/compile/internal/ssa: simplify boolean phis
* Decreases the generated code slightly.
* Similar to phiopt pass from gcc, except it only handles
booleans. Handling Eq/Neq had no impact on the generated code.

name       old time/op     new time/op     delta
Template       453ms ± 4%      451ms ± 4%    ~           (p=0.468 n=24+24)
GoTypes        1.55s ± 1%      1.55s ± 2%    ~           (p=0.287 n=24+25)
Compiler       6.53s ± 2%      6.56s ± 1%  +0.46%        (p=0.050 n=23+23)
MakeBash       45.8s ± 2%      45.7s ± 2%    ~           (p=0.866 n=24+25)

name       old text-bytes  new text-bytes  delta
HelloSize       676k ± 0%       676k ± 0%    ~     (all samples are equal)
CmdGoSize      8.07M ± 0%      8.07M ± 0%  -0.03%        (p=0.000 n=25+25)

Change-Id: Ia62477b7554127958a14cb27f85849b095d63663
Reviewed-on: https://go-review.googlesource.com/20090
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-01 17:56:13 +00:00
Gerrit Code Review
acdb0da47d Merge "[dev.ssa] Merge remote-tracking branch 'origin/master' into ssamerge" into dev.ssa 2016-02-29 23:19:17 +00:00
Keith Randall
4fffd4569d [dev.ssa] Merge remote-tracking branch 'origin/master' into ssamerge
(Last?) Semi-regular merge from tip to dev.ssa.

Conflicts:
	src/cmd/compile/internal/gc/closure.go
	src/cmd/compile/internal/gc/gsubr.go
	src/cmd/compile/internal/gc/lex.go
	src/cmd/compile/internal/gc/pgen.go
	src/cmd/compile/internal/gc/syntax.go
	src/cmd/compile/internal/gc/walk.go
	src/cmd/internal/obj/pass.go

Change-Id: Ib5ea8bf74d420f4902a9c6208761be9f22371ae7
2016-02-29 13:32:20 -08:00
Robert Griesemer
ed1a5e5da6 cmd/compile: cleanup number lexing
Change-Id: Ib0dd458d4ab1c58a2baf36491e288ac32e2ff99e
Reviewed-on: https://go-review.googlesource.com/19962
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-29 19:00:10 +00:00
Alexandru Moșoi
bdea1d58cf [dev.ssa] cmd/compile/internal/ssa: remove proven redundant controls.
* It does very simple bounds checking elimination. E.g.
removes the second check in for i := range a { a[i]++; a[i++]; }
* Improves on the following redundant expression:
return a6 || (a6 || (a6 || a4)) || (a6 || (a4 || a6 || (false || a6)))
* Linear in the number of block edges.

I patched in CL 12960 that does bounds, nil and constant propagation
to make sure this CL is not just redundant. Size of pkg/tool/linux_amd64/*
(excluding compile which is affected by this change):

With IsInBounds and IsSliceInBounds
-this -12960 92285080
+this -12960 91947416
-this +12960 91978976
+this +12960 91923088

Gain is ~110% of 12960.

Without IsInBounds and IsSliceInBounds (older run)
-this -12960 95515512
+this -12960 95492536
-this +12960 95216920
+this +12960 95204440

Shaves 22k on its own.

* Can we handle IsInBounds better with this? In
for i := range a { a[i]++; } the bounds checking at a[i]
is not eliminated.

Change-Id: I98957427399145fb33693173fd4d5a8d71c7cc20
Reviewed-on: https://go-review.googlesource.com/19710
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-28 19:48:20 +00:00
Matthew Dempsky
af558acc47 cmd/compile: fix contrived line number errors
If a general comment contains multiple newline characters, we can't
simply unread one and then re-lex it via the general whitespace lexing
phase, because then we'll reset lineno to the line before the "*/"
marker, rather than keeping it where we found the "/*" marker.

Also, for processing imports, call importfile before advancing the
lexer with p.next(), so that lineno reflects the line where we found
the import path, and not the token afterwards.

Fixes #14520.

Change-Id: I785a2d83d632280113d4b757de0d57c88ba2caf4
Reviewed-on: https://go-review.googlesource.com/19934
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-26 21:25:43 +00:00
Keith Randall
b462744e70 [dev.ssa] test: remove extra tests from non-SSA builds
non-SSA backends are all over the map as to whether nil checks
get removed or not.  amd64, 386, 386/387, arm are all subtly different.
Remove these extra checks for now, they are in nilptr3_ssa.go so they
won't get lost.

Change-Id: I2e0051f488fb2cb7278c6fdd44cb9d68b5778345
Reviewed-on: https://go-review.googlesource.com/19961
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-02-26 19:07:16 +00:00
Keith Randall
4a346e7489 [dev.ssa] cmd/compile: get rid of nil checks before float loads/stores
Just like we do for integer loads/stores.

Update #14511

Change-Id: Ic6ca6b54301438a5701ea5fb0be755451cb24d45
Reviewed-on: https://go-review.googlesource.com/19923
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Keith Randall <khr@golang.org>
2016-02-26 04:33:46 +00:00
Keith Randall
d3f15ff6bc [dev.ssa] cmd/compile: shrink stack guard
Our stack frame sizes look pretty good now.  Lower the stack
guard from 1024 to 720.
Tip is currently using 720.
We could go lower (to 640 at least) except PPC doesn't like that.

Change-Id: Ie5f96c0e822435638223f1e8a2bd1a1eed68e6aa
Reviewed-on: https://go-review.googlesource.com/19922
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-02-25 22:32:48 +00:00
Robert Griesemer
539aa05a64 cmd/compile: towards simpler and faster lexing: always use getr
Always reading runes (rather than bytes) has negligible overhead
(a simple if at the moment - it can be eliminated eventually) but
simplifies the lexer logic and opens up the door for speedups.
In the process remove many int conversions that are now not needed
anymore.

Also, because identifiers are now more easily recognized, remove
talph label and move identifier lexing "in place".

Also, instead of accepting all chars < 0x80 and then check for
"frogs", only permit valid characters in the first place. Removes
an extra call for common simple tokens and leads to simpler logic.

`time go build -a net/http` (best of 5 runs) seems 1% faster.
Assuming this is in the noise, there is no noticeable performance
degradation with this change.

Change-Id: I3454c9bf8b91808188cf7a5f559341749da9a1eb
Reviewed-on: https://go-review.googlesource.com/19847
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-24 04:36:25 +00:00
Keith Randall
80bc512449 [dev.ssa] Merge remote-tracking branch 'origin/master' into mergebranch
Semi-regular merge from tip to dev.ssa.

Change-Id: If7d2269f267bcbc0ecd3a483d349951044470e3f
2016-02-23 14:42:20 -08:00
Robert Griesemer
d1cc7f70cd cmd/compile: give informative error instead of "stupid shift"
Fixes #13940.

Change-Id: I00fe377c949e5be4cbc035f6ca18e547e326bfba
Reviewed-on: https://go-review.googlesource.com/19856
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-23 22:31:35 +00:00
Matthew Dempsky
7d3a40978a cmd/compile: refactor export data parsing
Merge push_parser and pop_parser into a single parse_import function
and inline unimportfile. Shake out function boundaries a little bit so
that the symmetry is readily visible.

Move the import_package call into parse_import (and inline
import_there into import_package).  This means importfile no longer
needs to provide fake import data to be needlessly lexed/parsed every
time it's called.

Also, instead of indicating import success/failure by whether the next
token is "package", import_spec can just check whether importpkg is
non-nil.

Tangentially, this somehow alters the diagnostics produced for
test/fixedbugs/issue11610.go.  However, the new diagnostics are more
consistent with those produced when the empty import statement is
absent, which seems more desirable than maintaining the previous
errors.

Change-Id: I5cd1c22aa14da8a743ef569ff084711d137279d5
Reviewed-on: https://go-review.googlesource.com/19650
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-02-20 04:31:42 +00:00
David Chase
fb2af2b35b cmd/compile: don't walk field-name syntax in esc.go
Walking the field name as if it were an expression
caused a called to haspointers with a TFIELD, which panics.
Trigger was a field at a large offset within a large struct,
combined with a struct literal expression mentioning that
field.

Fixes #14405

Change-Id: I4589badae27cf3d7cf365f3a66c13447512f41f9
Reviewed-on: https://go-review.googlesource.com/19699
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-19 19:40:49 +00:00
Tal Shprecher
5c5e8d4105 cmd/compile: avoid leak of dottype expression if type does not contain pointers.
Fixes #13805

Change-Id: Ica9aae2e054b74f67d28ab27f72c52a3f03eeb59
Reviewed-on: https://go-review.googlesource.com/19489
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-02-19 16:10:14 +00:00
Russ Cox
51b624e6a2 cmd/link: remove alternate -X flag spelling
The Go 1.6 release notes say we'll remove the “-X name value” form
(in favor of the “-X name=value” form) in Go 1.7.
Do that.

Also establish the doc/go1.7.txt file.

Change-Id: Ie4565a6bc5dbcf155181754d8d92bfbb23c75338
Reviewed-on: https://go-review.googlesource.com/19614
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-02-19 01:35:25 +00:00
Russ Cox
feb2a5d610 cmd/compile: print struct tags in var decl in inlined func body
This bug was introduced in golang.org/cl/18217,
while trying to fix #13777.

Originally I wanted to just disable inlining for the case
being handled incorrectly, but it's fairly difficult to detect
and much easier just to fix. Since the case being handled
incorrectly was inlined correctly in Go 1.5, not inlining it
would also be somewhat of a regression.
So just fix it.

Test case copied from Ian's CL 19520.

The mistake to worry about in this CL would be relaxing
the condition too much (we now print the note more often
than we did yesterday). To confirm that we'd catch this mistake,
I checked that changing (!fmtbody || !t.Funarg) to (true) does
cause fixedbugs/issue13777.go to fail. And putting it back
to what is written in this CL makes that test pass again
as well as the new fixedbugs/issue14331.go.
So I believe that the new condition is correct for both constraints.

Fixes #14331.

Change-Id: I91f75a4d5d07c53af5caea1855c780d9874b8df6
Reviewed-on: https://go-review.googlesource.com/19514
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-02-16 19:39:10 +00:00
Keith Randall
e3033fc535 cmd/compile: add write barrier to type switch
Type switches need write barriers if the written-to
variable is heap allocated.

For the added needwritebarrier call, the right arg doesn't
really matter, I just pass something that will never disqualify
the write barrier.  The left arg is the one that matters.

Fixes #14306

Change-Id: Ic2754167cce062064ea2eeac2944ea4f77cc9c3b
Reviewed-on: https://go-review.googlesource.com/19481
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-12 21:07:21 +00:00
Keith Randall
eb0cff9a76 [dev.ssa] Merge remote-tracking branch 'origin/master' into mergebranch
Semi-regular merge from tip to dev.ssa.

Two fixes:
1) Mark selectgo as not returning.  This caused problems
   because there are no VARKILL ops on the selectgo path,
   causing things to be marked live that shouldn't be.
2) Tell the amd64 assembler that addressing modes like
   name(SP)(AX*4) are ok.

Change-Id: I9ca81c76391b1a65cc47edc8610c70ff1a621913
2016-02-10 09:31:41 -08:00
Robert Griesemer
d37d76af43 cmd/compile: fix parsing of inlined interface types with unexported methods
Fixes #14164.

Change-Id: Ib1d1d29674c99cf88e0ae12724823a31f5dbb95c
Reviewed-on: https://go-review.googlesource.com/19087
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-02-01 20:29:19 +00:00