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2364 Commits

Author SHA1 Message Date
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