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3458 Commits

Author SHA1 Message Date
LE Manh Cuong
3e9d8e2e1b test/fixedbugs: fix some tests will not be run
Currently, some tests under test/fixedbugs never run:

	$ for d in test/fixedbugs/*.dir; do
	  ! test -f "${d%.dir}.go" && echo "$d"
	done
	test/fixedbugs/issue15071.dir
	test/fixedbugs/issue15609.dir
	test/fixedbugs/issue29612.dir

Because they missed the corresponding ".go" file, so "go run run.go"
will skip them.

Add missing ".go" files for those tests to make sure they will be
collected and run.

While at it, add another action "runindir", which does "go run ."
inside the t.goDirName then check the output.

Change-Id: I88000b3663a6a615d90c1cf11844ea0377403e3d
Reviewed-on: https://go-review.googlesource.com/c/go/+/177798
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-05-23 01:39:41 +00:00
Matthew Dempsky
94a9dad8fd cmd/compile: fix capture-by-reference of return parameters
As an optimization, function literals capture variables by value when
they're not assigned and their address has not been taken. Because
result parameters are implicitly assigned through return statements
(which do not otherwise set the "assigned" flag), result parameters
are explicitly handled to always capture by reference.

However, the logic was slightly mistaken because it was only checking
if the variable in the immediately enclosing context was a return
parameter, whereas in a multiply-nested function literal it would
itself be another closure variable (PAUTOHEAP) rather than a return
parameter (PPARAMOUT).

The fix is to simply test the outermost variable, like the rest of the
if statement's tests were already doing.

Fixes #32175.

Change-Id: Ibadde033ff89a1b47584b3f56c0014d8e5a74512
Reviewed-on: https://go-review.googlesource.com/c/go/+/178541
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-05-22 18:43:09 +00:00
Keith Randall
6105e8b419 runtime: revert init order changes
First, remove the randomization of initialization order.

Then, revert to source code order instead of sorted package path order.

This restores the behavior that was in 1.12.

A larger change which will implement the suggestion in #31636 will
wait for 1.14. It's too complicated for 1.13 at this point (it has
tricky interactions with plugins).

Fixes #31636

Change-Id: I35b48e8cc21cf9f93c0973edd9193d2eac197628
Reviewed-on: https://go-review.googlesource.com/c/go/+/178297
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-05-22 11:07:00 +00:00
LE Manh Cuong
2d357d8da8 cmd/compile: fix typecheck type alias makes wrong export symbol metadata
typecheck type alias always replaces the original definition of the symbol.
This is wrong behavior because if the symbol's definition is replaced by a
local type alias, it ends up being written to compiled file as an alias,
instead of the original type.

To fix, only replace the definition of symbol with global type alias.

Fixes #31959

Change-Id: Id85a15e8a9d6a4b06727e655a95dc81e63df633a
Reviewed-on: https://go-review.googlesource.com/c/go/+/177378
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2019-05-21 17:44:21 +00:00
Russ Cox
4f248e988a test: skip cross-arch codegen tests in all.bash
The test/codegen tests check all architectures
mentioned in the test file, but this requires
building at least the runtime for that architecture.
This CL changes the test to only check the local
architecture, leaving checking of other architectures
to the relevant builders, as usual.

This cuts 'go run run.go codegen' by 12r 78u 21s.

After this change, all.bash runs in ~4:40 on my laptop.

For #26473.

Change-Id: Ia0354d1aff2df2949f838528c8171410bc42dc8b
Reviewed-on: https://go-review.googlesource.com/c/go/+/177577
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-05-21 12:10:31 +00:00
fanzha02
822a9f537f cmd/compile: fix the error of absorbing boolean tests into block(FGE, FGT)
The CL 164718 mistyped the comparison flags. The rules for floating
point comparison should be GreaterThanF and GreaterEqualF. Fortunately,
the wrong optimizations were overwritten by other integer rules, so the
issue won't cause failure but just some performance impact.

The fixed CL optimizes the floating point test as follows.

source code: func foo(f float64) bool { return f > 4 || f < -4}
previous version: "FCMPD", "CSET\tGT", "CBZ"
fixed version: "FCMPD", BLE"

Add the test case.

Change-Id: Iea954fdbb8272b2d642dae0f816dc77286e6e1fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/177121
Reviewed-by: Ben Shi <powerman1st@163.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-05-16 13:46:25 +00:00
Keith Randall
a9e107c85c cmd/compile: make sure to initialize static entries of slices
If a slice's entries are sparse, we decide to initialize it dynamically
instead of statically. That's CL 151319.

But if we do initialize it dynamically, we still need to initialize
the static entries. Typically we do that, but the bug fixed here is
that we don't if the entry's value is itself an array or struct.

To fix, use initKindLocalCode to ensure that both static and
dynamic entries are initialized via code.

Fixes #31987

Change-Id: I1192ffdbfb5cd50445c1206c4a3d8253295201dd
Reviewed-on: https://go-review.googlesource.com/c/go/+/176904
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2019-05-14 16:36:38 +00:00
Cherry Zhang
23f3ea82b9 cmd/compile: correct the argument type in SETXXstore -> MOVBstore rules on AMD64
MOVBstore's value argument is a value, not a flag. We are storing
a byte so just use UInt8.

Fixes #31915.

Change-Id: Id799e5f44efc3a9c3d8480f6f25ad032c2a631bb
Reviewed-on: https://go-review.googlesource.com/c/go/+/176719
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2019-05-13 19:04:43 +00:00
Cherry Zhang
ce5ae2f4bc test: use a real use function in nilptr2.go
Adjust the dummy use function to a real use. As suggested by the
println calls in the test, nilptr2.go supposes to check that a
used nil pointer dereference panics. This use function is not
real enough so an optimized compiler such as gccgo could
eliminate the call.

The spec requires that even a dummy use would cause a panic.
Unfortunately, due to #31151 this is not true for gccgo at -O1 or
above.

Change-Id: Ie07c8a5969ab94dad82d4f7cfec30597c25b7c46
Reviewed-on: https://go-review.googlesource.com/c/go/+/176579
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-05-11 03:02:33 +00:00
Robert Griesemer
dc0388c565 cmd/compile: avoid compiler crash for recursive interface type
This change is a simple work-around to avoid a compiler crash
and provide a reasonable error message. A future change should
fix the root cause for this problem.

Fixes #23823.

Change-Id: Ifc80d9f4d35e063c378e54d5cd8d1cf4c0d2ec6a
Reviewed-on: https://go-review.googlesource.com/c/go/+/175518
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-05-07 18:42:17 +00:00
Keith Randall
04845fe78a reflect: special-case panic message when returning Value{} from MakeFunc function
Before this CL we used to panic with "nil pointer dereference" because
the value we're calling assignTo on is the zero Value. Provide a better
error message.

Fixes #28748

Change-Id: I7dd4c9e30b599863664d91e78cc45878d8b0052e
Reviewed-on: https://go-review.googlesource.com/c/go/+/175440
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-05-06 21:23:29 +00:00
Michael Munday
2c1b5130aa cmd/compile: add math/bits.{Add,Sub}64 intrinsics on s390x
This CL adds intrinsics for the 64-bit addition and subtraction
functions in math/bits. These intrinsics use the condition code
to propagate the carry or borrow bit.

To make the carry chains more efficient I've removed the
'clobberFlags' property from most of the load and store
operations. Originally these ops did clobber flags when using
offsets that didn't fit in a signed 20-bit integer, however
that is no longer true.

As with other platforms the intrinsics are faster when executed
in a chain rather than a loop because currently we need to spill
and restore the carry bit between each loop iteration. We may
be able to reduce the need to do this on s390x (e.g. by using
compare-and-branch instructions that do not clobber flags) in the
future.

name           old time/op  new time/op  delta
Add64          1.21ns ± 2%  2.03ns ± 2%  +67.18%  (p=0.000 n=7+10)
Add64multiple  2.98ns ± 3%  1.03ns ± 0%  -65.39%  (p=0.000 n=10+9)
Sub64          1.23ns ± 4%  2.03ns ± 1%  +64.85%  (p=0.000 n=10+10)
Sub64multiple  3.73ns ± 4%  1.04ns ± 1%  -72.28%  (p=0.000 n=10+8)

Change-Id: I913bbd5e19e6b95bef52f5bc4f14d6fe40119083
Reviewed-on: https://go-review.googlesource.com/c/go/+/174303
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-05-03 10:41:15 +00:00
LE Manh Cuong
004fb5cb8d cmd/compile: fix isStaticCompositeLiteral reports wrong for struct field
golang.org/cl/174498 add ONAME case to isStaticCompositeLiteral, to
detect global variable as compile-time constant.

It does report wrong for struct field, e.g:

	o := one{i: two{i: 42}.i}

field i in two{i: 42} was reported as static composite literal, while it
should not.

In general, adding ONAME case for isStaticCompositeLiteral is probably
wrong.

Fixes #31782

Change-Id: Icde7d43bbb002b75df5c52b948b7126a4265e07b
Reviewed-on: https://go-review.googlesource.com/c/go/+/174837
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-05-03 03:49:11 +00:00
Robert Griesemer
762953be28 cmd/compile: disable Go1.13 language features for -lang=go1.12 and below
Fixes   #31747.
Updates #19308.
Updates #12711.
Updates #29008.
Updates #28493.
Updates #19113.

Change-Id: I76d2fdbc7698cc4e0f31b7ae24cbb4d28afbb6a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/174897
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2019-05-02 00:42:51 +00:00
LE Manh Cuong
aaf40f8f98 cmd/compile: fix maplit init panics for dynamic entry
golang.org/cl/174498 removes dynamic map entry handling in maplit, by
filtering the static entry only. It panics if it see a dynamic entry.
It relies on order to remove all dynamic entries.

But after recursively call order on the statics, some static entries
become dynamic, e.g OCONVIFACE node:

	type i interface {
		j()
	}
	type s struct{}

	func (s) j() {}

	type foo map[string]i

	var f = foo{
		"1": s{},
	}

To fix it, we recursively call order on each static entry, if it changed
to dynamic, put entry to dynamic then.

Fixes #31777

Change-Id: I1004190ac8f2d1eaa4beb6beab989db74099b025
Reviewed-on: https://go-review.googlesource.com/c/go/+/174777
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-05-01 21:14:28 +00:00
Lynn Boger
e30aa166ea test: enable more memcombine tests for ppc64le
This enables more of the testcases in memcombine for ppc64le,
and adds more detail to some existing.

Change-Id: Ic522a1175bed682b546909c96f9ea758f8db247c
Reviewed-on: https://go-review.googlesource.com/c/go/+/174737
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-05-01 14:27:27 +00:00
Brian Kessler
4d9dd35806 cmd/compile: add signed divisibility rules
"Division by invariant integers using multiplication" paper
by Granlund and Montgomery contains a method for directly computing
divisibility (x%c == 0 for c constant) by means of the modular inverse.
The method is further elaborated in "Hacker's Delight" by Warren Section 10-17

This general rule can compute divisibilty by one multiplication, and add
and a compare for odd divisors and an additional rotate for even divisors.

To apply the divisibility rule, we must take into account
the rules to rewrite x%c = x-((x/c)*c) and (x/c) for c constant on the first
optimization pass "opt".  This complicates the matching as we want to match
only in the cases where the result of (x/c) is not also needed.
So, we must match on the expanded form of (x/c) in the expression x == c*(x/c)
in the "late opt" pass after common subexpresion elimination.

Note, that if there is an intermediate opt pass introduced in the future we
could simplify these rules by delaying the magic division rewrite to "late opt"
and matching directly on (x/c) in the intermediate opt pass.

On amd64, the divisibility check is 30-45% faster.

name                     old time/op  new time/op  delta`
DivisiblePow2constI64-4  0.83ns ± 1%  0.82ns ± 0%     ~     (p=0.079 n=5+4)
DivisibleconstI64-4      2.68ns ± 1%  1.87ns ± 0%  -30.33%  (p=0.000 n=5+4)
DivisibleWDivconstI64-4  2.69ns ± 1%  2.71ns ± 3%     ~     (p=1.000 n=5+5)
DivisiblePow2constI32-4  1.15ns ± 1%  1.15ns ± 0%     ~     (p=0.238 n=5+4)
DivisibleconstI32-4      2.24ns ± 1%  1.20ns ± 0%  -46.48%  (p=0.016 n=5+4)
DivisibleWDivconstI32-4  2.27ns ± 1%  2.27ns ± 1%     ~     (p=0.683 n=5+5)
DivisiblePow2constI16-4  0.81ns ± 1%  0.82ns ± 1%     ~     (p=0.135 n=5+5)
DivisibleconstI16-4      2.11ns ± 2%  1.20ns ± 1%  -42.99%  (p=0.008 n=5+5)
DivisibleWDivconstI16-4  2.23ns ± 0%  2.27ns ± 2%   +1.79%  (p=0.029 n=4+4)
DivisiblePow2constI8-4   0.81ns ± 1%  0.81ns ± 1%     ~     (p=0.286 n=5+5)
DivisibleconstI8-4       2.13ns ± 3%  1.19ns ± 1%  -43.84%  (p=0.008 n=5+5)
DivisibleWDivconstI8-4   2.23ns ± 1%  2.25ns ± 1%     ~     (p=0.183 n=5+5)

Fixes #30282
Fixes #15806

Change-Id: Id20d78263a4fdfe0509229ae4dfa2fede83fc1d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/173998
Run-TryBot: Brian Kessler <brian.m.kessler@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-30 22:02:07 +00:00
Keith Randall
e7d08b6fe6 cmd/compile: fix line numbers for index panics
In the statement x = a[i], the index panic should appear to come from
the line number of the '['. Previous to this CL we sometimes used the
line number of the '=' instead.

Fixes #29504

Change-Id: Ie718fd303c1ac2aee33e88d52c9ba9bcf220dea1
Reviewed-on: https://go-review.googlesource.com/c/go/+/174617
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-30 21:30:30 +00:00
Caleb Spare
fbc6a97222 testing: delay flag registration; move to an Init function
Any code that imports the testing package forces the testing flags to be
defined, even in non-test binaries. People work around this today by
defining a copy of the testing.TB interface just to avoid importing
testing.

Fix this by moving flag registration into a new function, testing.Init.
Delay calling Init until the testing binary begins to run, in
testing.MainStart.

Init is exported for cases where users need the testing flags to be
defined outside of a "go test" context. In particular, this may be
needed where testing.Benchmark is called outside of a test.

Fixes #21051

Change-Id: Ib7e02459e693c26ae1ba71bbae7d455a91118ee3
Reviewed-on: https://go-review.googlesource.com/c/go/+/173722
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-29 19:54:30 +00:00
Carlos Eduardo Seo
50ad09418e cmd/compile: intrinsify math/bits.Add64 for ppc64x
This change creates an intrinsic for Add64 for ppc64x and adds a
testcase for it.

name               old time/op  new time/op  delta
Add64-160          1.90ns ±40%  2.29ns ± 0%     ~     (p=0.119 n=5+5)
Add64multiple-160  6.69ns ± 2%  2.45ns ± 4%  -63.47%  (p=0.016 n=4+5)

Change-Id: I9abe6fb023fdf62eea3c9b46a1820f60bb0a7f97
Reviewed-on: https://go-review.googlesource.com/c/go/+/173758
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Run-TryBot: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
2019-04-28 23:51:04 +00:00
Brian Kessler
a28a942768 cmd/compile: add unsigned divisibility rules
"Division by invariant integers using multiplication" paper
by Granlund and Montgomery contains a method for directly computing
divisibility (x%c == 0 for c constant) by means of the modular inverse.
The method is further elaborated in "Hacker's Delight" by Warren Section 10-17

This general rule can compute divisibilty by one multiplication and a compare
for odd divisors and an additional rotate for even divisors.

To apply the divisibility rule, we must take into account
the rules to rewrite x%c = x-((x/c)*c) and (x/c) for c constant on the first
optimization pass "opt".  This complicates the matching as we want to match
only in the cases where the result of (x/c) is not also available.
So, we must match on the expanded form of (x/c) in the expression x == c*(x/c)
in the "late opt" pass after common subexpresion elimination.

Note, that if there is an intermediate opt pass introduced in the future we
could simplify these rules by delaying the magic division rewrite to "late opt"
and matching directly on (x/c) in the intermediate opt pass.

Additional rules to lower the generic RotateLeft* ops were also applied.

On amd64, the divisibility check is 25-50% faster.

name                     old time/op  new time/op  delta
DivconstI64-4            2.08ns ± 0%  2.08ns ± 1%     ~     (p=0.881 n=5+5)
DivisibleconstI64-4      2.67ns ± 0%  2.67ns ± 1%     ~     (p=1.000 n=5+5)
DivisibleWDivconstI64-4  2.67ns ± 0%  2.67ns ± 0%     ~     (p=0.683 n=5+5)
DivconstU64-4            2.08ns ± 1%  2.08ns ± 1%     ~     (p=1.000 n=5+5)
DivisibleconstU64-4      2.77ns ± 1%  1.55ns ± 2%  -43.90%  (p=0.008 n=5+5)
DivisibleWDivconstU64-4  2.99ns ± 1%  2.99ns ± 1%     ~     (p=1.000 n=5+5)
DivconstI32-4            1.53ns ± 2%  1.53ns ± 0%     ~     (p=1.000 n=5+5)
DivisibleconstI32-4      2.23ns ± 0%  2.25ns ± 3%     ~     (p=0.167 n=5+5)
DivisibleWDivconstI32-4  2.27ns ± 1%  2.27ns ± 1%     ~     (p=0.429 n=5+5)
DivconstU32-4            1.78ns ± 0%  1.78ns ± 1%     ~     (p=1.000 n=4+5)
DivisibleconstU32-4      2.52ns ± 2%  1.26ns ± 0%  -49.96%  (p=0.000 n=5+4)
DivisibleWDivconstU32-4  2.63ns ± 0%  2.85ns ±10%   +8.29%  (p=0.016 n=4+5)
DivconstI16-4            1.54ns ± 0%  1.54ns ± 0%     ~     (p=0.333 n=4+5)
DivisibleconstI16-4      2.10ns ± 0%  2.10ns ± 1%     ~     (p=0.571 n=4+5)
DivisibleWDivconstI16-4  2.22ns ± 0%  2.23ns ± 1%     ~     (p=0.556 n=4+5)
DivconstU16-4            1.09ns ± 0%  1.01ns ± 1%   -7.74%  (p=0.000 n=4+5)
DivisibleconstU16-4      1.83ns ± 0%  1.26ns ± 0%  -31.52%  (p=0.008 n=5+5)
DivisibleWDivconstU16-4  1.88ns ± 0%  1.89ns ± 1%     ~     (p=0.365 n=5+5)
DivconstI8-4             1.54ns ± 1%  1.54ns ± 1%     ~     (p=1.000 n=5+5)
DivisibleconstI8-4       2.10ns ± 0%  2.11ns ± 0%     ~     (p=0.238 n=5+4)
DivisibleWDivconstI8-4   2.22ns ± 0%  2.23ns ± 2%     ~     (p=0.762 n=5+5)
DivconstU8-4             0.92ns ± 1%  0.94ns ± 1%   +2.65%  (p=0.008 n=5+5)
DivisibleconstU8-4       1.66ns ± 0%  1.26ns ± 1%  -24.28%  (p=0.008 n=5+5)
DivisibleWDivconstU8-4   1.79ns ± 0%  1.80ns ± 1%     ~     (p=0.079 n=4+5)

A follow-up change will address the signed division case.

Updates #30282

Change-Id: I7e995f167179aa5c76bb10fbcbeb49c520943403
Reviewed-on: https://go-review.googlesource.com/c/go/+/168037
Run-TryBot: Brian Kessler <brian.m.kessler@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-27 20:46:46 +00:00
Brian Kessler
44343c777c cmd/compile: add signed divisibility by power of 2 rules
For powers of two (c=1<<k), the divisibility check x%c == 0 can be made
just by checking the trailing zeroes via a mask x&(c-1) == 0 even for signed
integers. This avoids division fix-ups when just divisibility check is needed.

To apply this rule, we match on the fixed-up version of the division. This is
neccessary because the mod and division rewrite rules are already applied
during the initial opt pass.

The speed up on amd64 due to elimination of unneccessary fix-up code is ~55%:

name                     old time/op  new time/op  delta
DivconstI64-4            2.08ns ± 0%  2.09ns ± 1%     ~     (p=0.730 n=5+5)
DivisiblePow2constI64-4  1.78ns ± 1%  0.81ns ± 1%  -54.66%  (p=0.008 n=5+5)
DivconstU64-4            2.08ns ± 0%  2.08ns ± 0%     ~     (p=0.683 n=5+5)
DivconstI32-4            1.53ns ± 0%  1.53ns ± 1%     ~     (p=0.968 n=4+5)
DivisiblePow2constI32-4  1.79ns ± 1%  0.81ns ± 1%  -54.97%  (p=0.008 n=5+5)
DivconstU32-4            1.78ns ± 1%  1.80ns ± 2%     ~     (p=0.206 n=5+5)
DivconstI16-4            1.54ns ± 2%  1.54ns ± 0%     ~     (p=0.238 n=5+4)
DivisiblePow2constI16-4  1.78ns ± 0%  0.81ns ± 1%  -54.72%  (p=0.000 n=4+5)
DivconstU16-4            1.00ns ± 5%  1.01ns ± 1%     ~     (p=0.119 n=5+5)
DivconstI8-4             1.54ns ± 0%  1.54ns ± 2%     ~     (p=0.571 n=4+5)
DivisiblePow2constI8-4   1.78ns ± 0%  0.82ns ± 8%  -53.71%  (p=0.008 n=5+5)
DivconstU8-4             0.93ns ± 1%  0.93ns ± 1%     ~     (p=0.643 n=5+5)

A follow-up CL will address the general case of x%c == 0 for signed integers.

Updates #15806

Change-Id: Iabadbbe369b6e0998c8ce85d038ebc236142e42a
Reviewed-on: https://go-review.googlesource.com/c/go/+/173557
Run-TryBot: Brian Kessler <brian.m.kessler@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-25 03:00:32 +00:00
Josh Bleecher Snyder
2693b42466 cmd/compile: don't initialize blank struct fields
We already skipped blank field initialization in non-global contexts.
This change makes the global context treatment match.

Fixes #31546

Change-Id: I40acce49b0a9deb351ae0da098f4c114e425ec63
Reviewed-on: https://go-review.googlesource.com/c/go/+/173723
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-25 01:30:56 +00:00
Than McIntosh
57076b8e6e test: new test for issue 31637
This pair of packages caused a crash in gollvm, due to a glitch in the
way the front end handles empty/non-name parameters for functions that
are inline candidates.

Updates #31637.

Change-Id: I571c0658a00974dd36025e571638c0c836a3cdfd
Reviewed-on: https://go-review.googlesource.com/c/go/+/173617
Run-TryBot: Benny Siegert <bsiegert@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-04-24 19:55:13 +00:00
Keith Randall
17615969b6 Revert "cmd/compile: add signed divisibility by power of 2 rules"
This reverts CL 168038 (git 68819fb6d2)

Reason for revert: Doesn't work on 32 bit archs.

Change-Id: Idec9098060dc65bc2f774c5383f0477f8eb63a3d
Reviewed-on: https://go-review.googlesource.com/c/go/+/173442
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-23 21:23:18 +00:00
Brian Kessler
68819fb6d2 cmd/compile: add signed divisibility by power of 2 rules
For powers of two (c=1<<k), the divisibility check x%c == 0 can be made
just by checking the trailing zeroes via a mask x&(c-1)==0 even for signed
integers.  This avoids division fixups when just divisibility check is needed.

To apply this rule the generic divisibility rule for  A%B = A-(A/B*B) is disabled
on the "opt" pass, but this does not affect generated code as this rule is applied
later.

The speed up on amd64 due to elimination of unneccessary fixup code is ~55%:

name                     old time/op  new time/op  delta
DivconstI64-4            2.08ns ± 0%  2.07ns ± 0%     ~     (p=0.079 n=5+5)
DivisiblePow2constI64-4  1.78ns ± 1%  0.81ns ± 1%  -54.55%  (p=0.008 n=5+5)
DivconstU64-4            2.08ns ± 0%  2.08ns ± 0%     ~     (p=1.000 n=5+5)
DivconstI32-4            1.53ns ± 0%  1.53ns ± 0%     ~     (all equal)
DivisiblePow2constI32-4  1.79ns ± 1%  0.81ns ± 4%  -54.75%  (p=0.008 n=5+5)
DivconstU32-4            1.78ns ± 1%  1.78ns ± 1%     ~     (p=1.000 n=5+5)
DivconstI16-4            1.54ns ± 2%  1.53ns ± 0%     ~     (p=0.333 n=5+4)
DivisiblePow2constI16-4  1.78ns ± 0%  0.79ns ± 1%  -55.39%  (p=0.000 n=4+5)
DivconstU16-4            1.00ns ± 5%  0.99ns ± 1%     ~     (p=0.730 n=5+5)
DivconstI8-4             1.54ns ± 0%  1.53ns ± 0%     ~     (p=0.714 n=4+5)
DivisiblePow2constI8-4   1.78ns ± 0%  0.80ns ± 0%  -55.06%  (p=0.000 n=5+4)
DivconstU8-4             0.93ns ± 1%  0.95ns ± 1%   +1.72%  (p=0.024 n=5+5)

A follow-up CL will address the general case of x%c == 0 for signed integers.

Updates #15806

Change-Id: I0d284863774b1bc8c4ce87443bbaec6103e14ef4
Reviewed-on: https://go-review.googlesource.com/c/go/+/168038
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-23 20:35:54 +00:00
Keith Randall
fd788a86b6 cmd/compile: always mark atColumn1 results as statements
In 31618, we end up comparing the is-stmt-ness of positions
to repurpose real instructions as inline marks. If the is-stmt-ness
doesn't match, we end up not being able to remove the inline mark.

Always use statement-full positions to do the matching, so we
always find a match if there is one.

Also always use positions that are statements for inline marks.

Fixes #31618

Change-Id: Idaf39bdb32fa45238d5cd52973cadf4504f947d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/173324
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2019-04-23 17:39:11 +00:00
Keith Randall
43001a0dc9 cmd/compile: use correct package name for stack object symbol
Stack object generation code was always using the local package name
for its symbol. Normally that doesn't matter, as we usually only
compile functions in the local package. But for wrappers, the compiler
generates functions which live in other packages. When there are two
other packages with identical functions to wrap, the same name appears
twice, and the compiler goes boom.

Fixes #31252

Change-Id: I7026eebabe562cb159b8b6046cf656afd336ba25
Reviewed-on: https://go-review.googlesource.com/c/go/+/171464
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2019-04-22 17:40:48 +00:00
erifan01
f8f265b9cf cmd/compile: intrinsify math/bits.Sub64 for arm64
This CL instrinsifies Sub64 with arm64 instruction sequence NEGS, SBCS,
NGC and NEG, and optimzes the case of borrowing chains.

Benchmarks:
name              old time/op       new time/op       delta
Sub-64            2.500000ns +- 0%  2.048000ns +- 1%  -18.08%  (p=0.000 n=10+10)
Sub32-64          2.500000ns +- 0%  2.500000ns +- 0%     ~     (all equal)
Sub64-64          2.500000ns +- 0%  2.080000ns +- 0%  -16.80%  (p=0.000 n=10+7)
Sub64multiple-64  7.090000ns +- 0%  2.090000ns +- 0%  -70.52%  (p=0.000 n=10+10)

Change-Id: I3d2664e009a9635e13b55d2c4567c7b34c2c0655
Reviewed-on: https://go-review.googlesource.com/c/go/+/159018
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-22 14:40:20 +00:00
Josh Bleecher Snyder
68d4b1265e cmd/compile: reduce bits.Div64(0, lo, y) to 64 bit division
With this change, these two functions generate identical code:

func f(x uint64) (uint64, uint64) {
	return bits.Div64(0, x, 5)
}

func g(x uint64) (uint64, uint64) {
	return x / 5, x % 5
}

Updates #31582

Change-Id: Ia96c2e67f8af5dd985823afee5f155608c04a4b6
Reviewed-on: https://go-review.googlesource.com/c/go/+/173197
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-20 19:34:03 +00:00
Matthew Dempsky
9f9e17a82f cmd/compile: fix ICE from go/defer call to variadic function
The special case logic for go/defer arguments in Escape.call was
scattered around a bit and was somewhat inconsistently handled across
different types of function calls and parameters. This CL pulls the
logic out into a separate callStmt method that's used uniformly for
all kinds of function calls and arguments.

Fixes #31573.

Change-Id: Icdcdf611754dc3fcf1af7cb52879fb4b73a7a31f
Reviewed-on: https://go-review.googlesource.com/c/go/+/173019
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-04-19 20:45:14 +00:00
David Chase
376ce8c880 cmd/compile: shortcut intrinsic inlining AFTER getcallerXX check
A check in inl.go to prevent inlining of functions calling
either getcallerpc or getcallersp does not work when these
functions are intrinsics. Swap checks to fix.

Includes test.

No bug, this was discovered in the course of a ridiculous
experiment with inlining.

Change-Id: Ie1392523bb89882d586678f2674e1a4eadc5e431
Reviewed-on: https://go-review.googlesource.com/c/go/+/172217
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-19 20:18:29 +00:00
Matthew Dempsky
b5946ed48d test: fix escape_runtime_atomic.go
Casp1 is implemented in Go on js/wasm, so escape analysis correctly
determines that the "old" parameter does not escape (which is good).

Unfortunately, test/run.go doesn't have a way to indicate that ERROR
messages are optional, and cmd/compile only emits diagnostics for "var
x int" when it's moved to the heap; not when it stays on the stack.

To accomodate that this test currently passes on some GOARCHes but not
others, rewrite the Casp1 test to use "x := new(int)" and allow both
"new(int) escapes to heap" or "new(int) does not escape".

Updates #31525.

Change-Id: I40150a7ff9042f184386ccdb2d4d428f63e8ba4f
Reviewed-on: https://go-review.googlesource.com/c/go/+/172602
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-17 22:55:26 +00:00
Matthew Dempsky
9dce58d30d runtime/internal/atomic: remove bad go:noescape annotations on Loadp
The //go:noescape directive says that arguments don't leak at all,
which is too aggressive of a claim for functions that return pointers
derived from their parameters.

Remove the directive for now. Long term fix will require a new
directive that allows more fine-grained control over escape analysis
information supplied for functions implemented in assembly.

Also, update the BAD comments in the test cases for Loadp: we really
want that *ptr leaks to the result parameter, not that *ptr leaks to
the heap.

Updates #31525.

Change-Id: Ibfa61f2b70daa7ed3223056b57eeee777eef2e31
Reviewed-on: https://go-review.googlesource.com/c/go/+/172578
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-04-17 19:09:15 +00:00
Michael Fraenkel
f85d0e32e5 test: add escape regress for empty variadic function
Fixes #30898

Change-Id: I903dd8ed2b10c49b2291ad0858774f3ca2f5b223
Reviewed-on: https://go-review.googlesource.com/c/go/+/172422
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-17 17:05:53 +00:00
Matthew Dempsky
ff3ae455d9 test: add regress test cases for self-assignment
Cherry pointed out this case in review for CL 136496. That CL was
slightly too aggressive, and I likely would have made the same mistake
if I tried it myself.

Updates #27772.

Change-Id: I1fafabb9f8d9aba0494aa71333a4e17cf1bac5c8
Reviewed-on: https://go-review.googlesource.com/c/go/+/172421
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-04-17 16:36:56 +00:00
Matthew Dempsky
52d9ce89ef test: add escape regress tests for runtime and sync atomics
There weren't any tests to make sure these work correctly, and this
led to escape analysis regressions in both linux/s390x and js/wasm.

The underlying issue that cmd/compile is only getting some of these
correct because escape analysis doesn't understand //go:linkname is
still present, but at least this addresses the fragility aspect.

Updates #15283.

Change-Id: I546aee1899d098b2e3de45e9b33c3ca22de485f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/172420
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-04-17 16:36:30 +00:00
Ainar Garipov
7cdacf558f test: add regress test for issue 28369
Also gofmt test/escape5.go.

Fixes #28369.

Change-Id: I0a11748fd2b5cf01cb5437ae15827d9db91c0c0d
Reviewed-on: https://go-review.googlesource.com/c/go/+/172358
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-16 21:01:30 +00:00
LE Manh Cuong
644543dd64 cmd/compile: fix const declaration group broken with closure
In typecheckclosure, a xfunc node will be put to xtop. But that node can
be shared between multiple closures, like in a const declaration group:

const (
	x = unsafe.Sizeof(func() {})
	y
)

It makes a xfunc node appears multiple times in xtop, causing duplicate
initLSym run.

To fix this issue, we only do typecheck for xfunc one time, and setup
closure node earlier in typecheckclosure process.

Fixes #30709

Change-Id: Ic924a157ee9f3e5d776214bef5390849ddc8aab9
Reviewed-on: https://go-review.googlesource.com/c/go/+/172298
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-16 19:07:42 +00:00
Matthew Dempsky
a9831633be cmd/compile: update escape analysis tests for newescape
The new escape analysis implementation tries to emit debugging
diagnostics that are compatible with the existing implementation, but
there's a handful of cases that are easier to handle by updating the
test expectations instead.

For regress tests that need updating, the original file is copied to
oldescapeXXX.go.go with -newescape=false added to the //errorcheck
line, while the file is updated in place with -newescape=true and new
test requirements.

Notable test changes:

1) escape_because.go looks for a lot of detailed internal debugging
messages that are fairly particular to how esc.go works and that I
haven't attempted to port over to escape.go yet.

2) There are a lot of "leaking param: x to result ~r1 level=-1"
messages for code like

    func(p *int) *T { return &T{p} }

that were simply wrong. Here &T must be heap allocated unconditionally
(because it's being returned); and since p is stored into it, p
escapes unconditionally too. esc.go incorrectly reports that p escapes
conditionally only if the returned pointer escaped.

3) esc.go used to print each "leaking param" analysis result as it
discovered them, which could lead to redundant messages (e.g., that a
param leaks at level=0 and level=1). escape.go instead prints
everything at the end, once it knows the shortest path to each sink.

4) esc.go didn't precisely model direct-interface types, resulting in
some values unnecessarily escaping to the heap when stored into
non-escaping interface values.

5) For functions written in assembly, esc.go only printed "does not
escape" messages, whereas escape.go prints "does not escape" or
"leaking param" as appropriate, consistent with the behavior for
functions written in Go.

6) 12 tests included "BAD" annotations identifying cases where esc.go
was unnecessarily heap allocating something. These are all fixed by
escape.go.

Updates #23109.

Change-Id: Iabc9eb14c94c9cadde3b183478d1fd54f013502f
Reviewed-on: https://go-review.googlesource.com/c/go/+/170447
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2019-04-16 16:20:39 +00:00
Than McIntosh
d86c35e523 test: add testcases for gccgo bug
Add a couple of testcase for a gccgo type checking bug.

Updates #31412.

Change-Id: I7a813dafde78e4add1432602d2af5fe879415e1c
Reviewed-on: https://go-review.googlesource.com/c/go/+/171761
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-11 20:17:26 +00:00
Cherry Zhang
8d86ef2216 runtime: set itab.fun[0] only on successful conversion
For a failed interface conversion not in ",ok" form, getitab
calls itab.init to get the name of the missing method for the
panic message. itab.init will try to find the methods, populate
the method table as it goes. When some method is missing, it sets
itab.fun[0] to 0 before return. There is a small window that
itab.fun[0] could be non-zero.

If concurrently, another goroutine tries to do the same interface
conversion, it will read the same itab's fun[0]. If this happens
in the small window, it sees a non-zero fun[0] and thinks the
conversion succeeded, which is bad.

Fix the race by setting fun[0] to non-zero only when we know the
conversion succeeds. While here, also simplify the syntax
slightly.

Fixes #31419.

Change-Id: Ied34d3043079eb933e330c5877b85e13f98f1916
Reviewed-on: https://go-review.googlesource.com/c/go/+/171759
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-11 18:59:57 +00:00
Keith Randall
48ef01051a cmd/compile: handle new panicindex/slice names in optimizations
These new calls should not prevent NOSPLIT promotion, like the old ones.
These new calls should not prevent racefuncenter/exit removal.

(The latter was already true, as the new calls are not yet lowered
to StaticCalls at the point where racefuncenter/exit removal is done.)

Add tests to make sure we don't regress (again).

Fixes #31219

Change-Id: I3fb6b17cdd32c425829f1e2498defa813a5a9ace
Reviewed-on: https://go-review.googlesource.com/c/go/+/170639
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2019-04-03 21:24:17 +00:00
smasher164
60736733ec cmd/compile: return assignment mismatch error in var declarations
Some var declarations return "extra expression" or "missing expression"
errors when they should return “assignment mismatch” instead. Change
the returned error messages to exhibit the desired behavior.

Fixes #30085.

Change-Id: I7189355fbb0f976d70100779db4f81a9ae64fb11
Reviewed-on: https://go-review.googlesource.com/c/go/+/161558
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
2019-04-03 21:14:58 +00:00
Matthew Dempsky
556b3f5bdf test: add regress tests for unsafe.Pointer rules
Updates #23109.

Change-Id: I55f7860c868acc948a6397ab6a9295e177724a56
Reviewed-on: https://go-review.googlesource.com/c/go/+/170450
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-04-03 16:03:55 +00:00
Matthew Dempsky
131eb8fbf8 cmd/compile: trim more unnecessary escape analysis messages
"leaking closure reference" is redundant for similar reasons as "&x
escapes to heap" for OADDR nodes: the reference itself does not
allocate, and we already report when the referenced variable is moved
to heap.

"mark escaped content" is redundant with "leaking param content".

Updates #23109.

Change-Id: I1ab599cb1e8434f1918dd80596a70cba7dc8a0cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/170321
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-02 18:00:32 +00:00
Matthew Dempsky
abefcac10a cmd/compile: skip escape analysis diagnostics for OADDR
For most nodes (e.g., OPTRLIT, OMAKESLICE, OCONVIFACE), escape
analysis prints "escapes to heap" or "does not escape" to indicate
whether that node's allocation can be heap or stack allocated.

These messages are also emitted for OADDR, even though OADDR does not
actually allocate anything itself. Moreover, it's redundant because
escape analysis already prints "moved to heap" diagnostics when an
OADDR node like "&x" causes x to require heap allocation.

Because OADDR nodes don't allocate memory, my escape analysis rewrite
doesn't naturally emit the "escapes to heap" / "does not escape"
diagnostics for them. It's also non-trivial to replicate the exact
semantics esc.go uses for OADDR.

Since there are so many of these messages, I'm disabling them in this
CL by themselves. I modified esc.go to suppress the Warnl calls
without any other behavior changes, and then used a shell script to
automatically remove any ERROR messages mentioned by run.go in
"missing error" or "no match for" lines.

Fixes #16300.
Updates #23109.

Change-Id: I3993e2743c3ff83ccd0893f4e73b366ff8871a57
Reviewed-on: https://go-review.googlesource.com/c/go/+/170319
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
2019-04-02 16:34:03 +00:00
LE Manh Cuong
5fc55b3180 cmd/compile: use FmtLeft to generate symbol name for unexported interface methods
The bug in 29612 is that there are two similar-looking anonymous interface
types in two different packages, ./p1/ssa and ./p2/ssa:

v.(interface{ foo() }).foo()

These types should be treated differently because the unexported method
makes the types different (according to the spec).

But when generating the type descriptors for those two types, they
both have the name "interface { ssa.foo() }". They thus get the same
symbol, and the linker happily unifies them. It picks an arbitrary one
for the runtime to use, but that breaks conversions from concrete types
that have a foo method from the package which had its interface type
overwritten.

We need to encode the metadata symbol for unexported methods as package
path qualified (The same as we did in CL 27791 for struct fields).

So switching from FmtUnsigned to Fmtleft by default fixes the issue.
In case of generating namedata, FmtUnsigned is used.

The benchmark result ends up in no significant change of compiled binary
compare to the immediate parent.

Fixes #29612

Change-Id: I775aff91ae4a1bb16eb18a48d55e3b606f3f3352
Reviewed-on: https://go-review.googlesource.com/c/go/+/170157
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2019-04-01 17:27:06 +00:00
zdjones
2d41444ad0 cmd/compile: make prove learn index >= 0 from successful bounds checks
When branching at a bounds check for indexing or slicing ops, prove currently
only learns from the upper bound. On the positive branch, we currently learn
i < len(a) (or i <= len(a)) in both the signed and unsigned domains.

This CL makes prove also learn from the lower bound. Specifically, on the
positive branch from index or slicing ops, prove will now ALSO learn i >= 0 in
the signed domain (this fact is of no value in the unsigned domain).

The substantive change itself is only an additional call to addRestrictions,
though I've also inverted the nested switch statements around that call for the
sake of clarity.

This CL removes 92 bounds checks from std and cmd. It passes all tests and
shows no deltas on compilecmp.

Fixes #28885

Change-Id: I13eccc36e640eb599fa6dc5aa3be3c7d7abd2d9e
Reviewed-on: https://go-review.googlesource.com/c/go/+/170121
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2019-03-30 23:22:02 +00:00
David Chase
d8f60eea64 cmd/compile: enhance induction variable detection for unrolled loops
Would suggest extending capabilities (32-bit, unsigned, etc)
in separate CLs because prove bugs are so mystifying.

This implements the suggestion in this comment
https://go-review.googlesource.com/c/go/+/104041/10/src/cmd/compile/internal/ssa/loopbce.go#164
for inferring properly bounded iteration for loops of the form

for i := K0; i < KNN-(K-1); i += K
for i := K0; i <= KNN-K;    i += K

Where KNN is "known non negative" (i.e., len or cap) and K
is also not negative.  Because i <= KNN-K, i+K <= KNN and
no overflow occurs.

Also handles decreasing case (K1 > 0)
for i := KNN; i >= K0; i -= K1
which works when MININT+K1 < K0
(i.e. MININT < K0-K1, no overflow)

Signed only, also only 64 bit for now.

Change-Id: I5da6015aba2f781ec76c4ad59c9c48d952325fdc
Reviewed-on: https://go-review.googlesource.com/c/go/+/136375
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
2019-03-29 20:08:07 +00:00
zdjones
ddef157813 cmd/compile: make prove use poset to check non-negatives
Prove currently fails to remove bounds checks of the form:

if i >= 0 {              // hint that i is non-negative
    for i < len(data) {  // i becomes Phi in the loop SSA
        _ = data[i]      // data[Phi]; bounds check!!
	i++
    }
}

addIndVarRestrictions fails to identify that the loop induction
variable, (Phi), is non-negative. As a result, the restrictions,
i <= Phi < len(data), are only added for the signed domain. When
testing the bounds check, addBranchRestrictions is similarly unable
to infer that Phi is non-negative. As a result, the restriction,
Phi >= len(data), is only added/tested for the unsigned domain.

This CL changes the isNonNegative method to utilise the factTable's
partially ordered set (poset). It also adds field factTable.zero to
allow isNonNegative to query the poset using the zero(0) constant
found or created early in prove.

Fixes #28956

Change-Id: I792f886c652eeaa339b0d57d5faefbf5922fe44f
Reviewed-on: https://go-review.googlesource.com/c/go/+/161437
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2019-03-29 07:17:49 +00:00
Matthew Dempsky
9f6b21caea cmd/compile: fix ICE from invalid operations on float/complex constants
Typechecking treats all untyped numbers as integers for the purposes
of validating operators. However, when I refactoring constant
operation evalution in golang.org/cl/139901, I mistakenly interpreted
that the only invalid case that needed to be preserved was % (modulo)
on floating-point values.

This CL restores the other remaining cases that were dropped from that
CL. It also uses the phrasing "invalid operation" instead of "illegal
constant expression" for better consistency with the rest of
cmd/compile and with go/types.

Lastly, this CL extends setconst to recognize failed constant folding
(e.g., division by zero) so that we can properly mark those
expressions as broken rather than continuing forward with bogus values
that might lead to further spurious errors.

Fixes #31060.

Change-Id: I1ab6491371925e22bc8b95649f1a0eed010abca6
Reviewed-on: https://go-review.googlesource.com/c/go/+/169719
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-03-28 17:46:55 +00:00
Than McIntosh
ad8b7a70c5 test: fix fixedbugs/issue30908.go to work with no-opt builder
Update the issue 30908 test to work with the no-opt builder
(this requires a corresponding change in the linker as well).
As part of this change, 'rundir' tests are now linked without
passing "-w" to the linker.

Updates #30908.
Fixes #31034.

Change-Id: Ic776e1607075c295e409e1c8230aaf55a79a6323
Reviewed-on: https://go-review.googlesource.com/c/go/+/169161
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-03-27 17:53:36 +00:00
LE Manh Cuong
d47db6dc0c cmd/compile: fix literal struct interface {} lost passing by value
CL 135377 introduces pass strings and slices to convT2{E,I} by value.
Before that CL, all types, except interface will be allocated temporary
address. The CL changes the logic that only constant and type which
needs address (determine by convFuncName) will be allocated.

It fails to cover the case where type is static composite literal.
Adding condition to check that case fixes the issue.

Also, static composite literal node implies constant type, so consttype
checking can be removed.

Fixes #30956

Change-Id: Ifc750a029fb4889c2d06e73e44bf85e6ef4ce881
Reviewed-on: https://go-review.googlesource.com/c/go/+/168858
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-03-27 17:28:06 +00:00
Matthew Dempsky
c4f87ed26f cmd/compile: fix "append outside assignment" ICE
Some special-case code paths in order.go didn't expect OCALLFUNC to
have Ninit; in particular, OAS2FUNC and ODEFER/OGO failed to call
o.init on their child OCALLFUNC node. This resulted in not all of the
AST being properly ordered.

This was noticed because order is responsible for introducing an
invariant around how OAPPEND is used, which is enforced by walk.
However, there were perhaps simpler cases (e.g., simple order of
evaluation) that were being silently miscompiled.

Fixes #31010.

Change-Id: Ib928890ab5ec2aebd8e30a030bc2b404387f9123
Reviewed-on: https://go-review.googlesource.com/c/go/+/169257
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2019-03-26 02:20:09 +00:00
Than McIntosh
6582ee9cba test: new test for issue 30908
New test case designed to mimic the code in issue 30908, which
features duplicate but non-indentical DWARF abstract subprogram DIEs.

Updates #30908.

Change-Id: Iacb4b53e6a988e46c801cdac236cef883c553f8f
Reviewed-on: https://go-review.googlesource.com/c/go/+/168957
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
2019-03-25 15:00:08 +00:00
Than McIntosh
fbd74a8922 test: support -ldflags for "rundir" tests, new -P option
For "rundir" tests, allow users to add in linker flags as well as
compiler flags, e.g.

// rundir -m -ldflags -w

The directive above will pass "-m" to the compiler on each package compilation
and "-w" to the linker for the final link.

In addition, if "-P" is specified with 'rundir', then for each compile
pass in "-p <X>" to set the packagepath explicitly, which is closer to
how the compiler is run by 'go build'.

Change-Id: I04720011a89d1bd8dcb4f2ccb4af1d74f6a01da1
Reviewed-on: https://go-review.googlesource.com/c/go/+/168977
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-03-25 14:59:58 +00:00
erifan01
d0cbf9bf53 cmd/compile: follow up intrinsifying math/bits.Add64 for arm64
This CL deals with the additional comments of CL 159017.

Change-Id: I4ad3c60c834646d58dc0c544c741b92bfe83fb8b
Reviewed-on: https://go-review.googlesource.com/c/go/+/168857
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-22 15:09:47 +00:00
Cherry Zhang
f23c601bf9 cmd/compile: copy volatile values before emitting write barrier call
It is possible that a "volatile" value (one that can be clobbered
by preparing args of a call) to be used in multiple write barrier
calls. We used to copy the volatile value right before each call.
But this doesn't work if the value is used the second time, after
the first call where it is already clobbered. Copy it before
emitting any call.

Fixes #30977.

Change-Id: Iedcc91ad848d5ded547bf37a8359c125d32e994c
Reviewed-on: https://go-review.googlesource.com/c/go/+/168677
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-03-21 21:05:13 +00:00
Carlos Eduardo Seo
3023d7da49 cmd/compile/internal, cmd/internal/obj/ppc64: generate new count trailing zeros instructions on POWER9
This change adds new POWER9 instructions for counting trailing zeros (CNTTZW/CNTTZD)
to the assembler and generates them in SSA when GOPPC64=power9.

name                 old time/op  new time/op  delta
TrailingZeros-160    1.59ns ±20%  1.45ns ±10%  -8.81%  (p=0.000 n=14+13)
TrailingZeros8-160   1.55ns ±23%  1.62ns ±44%    ~     (p=0.593 n=13+15)
TrailingZeros16-160  1.78ns ±23%  1.62ns ±38%  -9.31%  (p=0.003 n=14+14)
TrailingZeros32-160  1.64ns ±10%  1.49ns ± 9%  -9.15%  (p=0.000 n=13+14)
TrailingZeros64-160  1.53ns ± 6%  1.45ns ± 5%  -5.38%  (p=0.000 n=15+13)

Change-Id: I365e6ff79f3ce4d8ebe089a6a86b1771853eb596
Reviewed-on: https://go-review.googlesource.com/c/go/+/167517
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
2019-03-20 20:27:00 +00:00
erifan01
5714c91b53 cmd/compile: intrinsify math/bits.Add64 for arm64
This CL instrinsifies Add64 with arm64 instruction sequence ADDS, ADCS
and ADC, and optimzes the case of carry chains.The CL also changes the
test code so that the intrinsic implementation can be tested.

Benchmarks:
name               old time/op       new time/op       delta
Add-224            2.500000ns +- 0%  2.090000ns +- 4%  -16.40%  (p=0.000 n=9+10)
Add32-224          2.500000ns +- 0%  2.500000ns +- 0%     ~     (all equal)
Add64-224          2.500000ns +- 0%  1.577778ns +- 2%  -36.89%  (p=0.000 n=10+9)
Add64multiple-224  6.000000ns +- 0%  2.000000ns +- 0%  -66.67%  (p=0.000 n=10+10)

Change-Id: I6ee91c9a85c16cc72ade5fd94868c579f16c7615
Reviewed-on: https://go-review.googlesource.com/c/go/+/159017
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-03-20 05:39:49 +00:00
Josh Bleecher Snyder
250b96a7bf cmd/compile: slightly optimize adding 128
'SUBQ $-0x80, r' is shorter to encode than 'ADDQ $0x80, r',
and functionally equivalent. Use it instead.

Shaves off a few bytes here and there:

file    before    after     Δ       %       
compile 25935856  25927664  -8192   -0.032% 
nm      4251840   4247744   -4096   -0.096% 

Change-Id: Ia9e02ea38cbded6a52a613b92e3a914f878d931e
Reviewed-on: https://go-review.googlesource.com/c/go/+/168344
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-03-19 19:44:52 +00:00
Keith Randall
ca36af215f cmd/compile: better write barrier removal when initializing new objects
When initializing a new object, we're often writing
1) to a location that doesn't have a pointer to a heap object
2) a pointer that doesn't point to a heap object

When both those conditions are true, we can avoid the write barrier.

This CL detects case 1 by looking for writes to known-zeroed
locations.  The results of runtime.newobject are zeroed, and we
perform a simple tracking of which parts of that object are written so
we can determine what part remains zero at each write.

This CL detects case 2 by looking for addresses of globals (including
the types and itabs which are used in interfaces) and for nil pointers.

Makes cmd/go 0.3% smaller. Some particular cases, like the slice
literal in #29573, can get much smaller.

TODO: we can remove actual zero writes also with this mechanism.

Update #29573

Change-Id: Ie74a3533775ea88da0495ba02458391e5db26cb9
Reviewed-on: https://go-review.googlesource.com/c/go/+/156363
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-03-18 21:16:19 +00:00
Keith Randall
7b916243d9 cmd/compile: rename init function from init.ializers back to init
The name change init -> init.ializers was initially required for
initialization code.

With CL 161337 there's no wrapper code any more, there's a data
structure instead (named .inittask). So we can go back to just
plain init appearing in tracebacks.

RELNOTE=yes

Update #29919. Followon to CL 161337.

Change-Id: I5a4a49d286df24b53b2baa193dfda482f3ea82a5
Reviewed-on: https://go-review.googlesource.com/c/go/+/167780
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-18 20:41:12 +00:00
Keith Randall
d949d0b925 cmd/compile: reorganize init functions
Instead of writing an init function per package that does the same
thing for every package, just write that implementation once in the
runtime. Change the compiler to generate a data structure that encodes
the required initialization operations.

Reduces cmd/go binary size by 0.3%+.  Most of the init code is gone,
including all the corresponding stack map info. The .inittask
structures that replace them are quite a bit smaller.

Most usefully to me, there is no longer an init function in every -S output.
(There is an .inittask global there, but it's much less distracting.)

After this CL we could change the name of the "init.ializers" function
back to just "init".

Update #6853

R=go1.13

Change-Id: Iec82b205cc52fe3ade4d36406933c97dbc9c01b1
Reviewed-on: https://go-review.googlesource.com/c/go/+/161337
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2019-03-18 20:10:55 +00:00
Matthew Dempsky
916e861fd9 cmd/compile: fix importing rewritten f(g()) calls
golang.org/cl/166983 started serializing the Ninit field of OCALL
nodes within function inline bodies (necessary to fix a regression in
building crypto/ecdsa with -gcflags=-l=4), but this means the Ninit
field needs to be typechecked when the imported function body is used.

It's unclear why this wasn't necessary for the crypto/ecdsa
regression.

Fixes #30907.

Change-Id: Id5f0bf3c4d17bbd6d5318913b859093c93a0a20c
Reviewed-on: https://go-review.googlesource.com/c/go/+/168199
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-18 19:43:38 +00:00
Keith Randall
2c423f063b cmd/compile,runtime: provide index information on bounds check failure
A few examples (for accessing a slice of length 3):

   s[-1]    runtime error: index out of range [-1]
   s[3]     runtime error: index out of range [3] with length 3
   s[-1:0]  runtime error: slice bounds out of range [-1:]
   s[3:0]   runtime error: slice bounds out of range [3:0]
   s[3:-1]  runtime error: slice bounds out of range [:-1]
   s[3:4]   runtime error: slice bounds out of range [:4] with capacity 3
   s[0:3:4] runtime error: slice bounds out of range [::4] with capacity 3

Note that in cases where there are multiple things wrong with the
indexes (e.g. s[3:-1]), we report one of those errors kind of
arbitrarily, currently the rightmost one.

An exhaustive set of examples is in issue30116[u].out in the CL.

The message text has the same prefix as the old message text. That
leads to slightly awkward phrasing but hopefully minimizes the chance
that code depending on the error text will break.

Increases the size of the go binary by 0.5% (amd64). The panic functions
take arguments in registers in order to keep the size of the compiled code
as small as possible.

Fixes #30116

Change-Id: Idb99a827b7888822ca34c240eca87b7e44a04fdd
Reviewed-on: https://go-review.googlesource.com/c/go/+/161477
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2019-03-18 17:33:38 +00:00
Than McIntosh
64b1889e2d test: new test for issue 30862
New test case, inspired by gccgo issue 30862.

Updates #30862.

Change-Id: I5e494b877e4fd142b8facb527471fe1fdef39c61
Reviewed-on: https://go-review.googlesource.com/c/go/+/167744
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-03-15 19:05:53 +00:00
Tobias Klauser
156c830bea cmd/compile: eliminate unnecessary type conversions in TrailingZeros(16|8) for arm
This follows CL 156999 which did the same for arm64.

name               old time/op  new time/op  delta
TrailingZeros-4    7.30ns ± 1%  7.30ns ± 0%     ~     (p=0.413 n=9+9)
TrailingZeros8-4   8.32ns ± 0%  7.17ns ± 0%  -13.77%  (p=0.000 n=10+9)
TrailingZeros16-4  8.30ns ± 0%  7.18ns ± 0%  -13.50%  (p=0.000 n=9+10)
TrailingZeros32-4  6.46ns ± 1%  6.47ns ± 1%     ~     (p=0.325 n=10+10)
TrailingZeros64-4  16.3ns ± 0%  16.2ns ± 0%   -0.61%  (p=0.000 n=7+10)

Change-Id: I7e9e1abf7e30d811aa474d272b2824ec7cbbaa98
Reviewed-on: https://go-review.googlesource.com/c/go/+/167797
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-03-15 18:37:22 +00:00
Matthew Dempsky
c0cfe9687f cmd/compile: rewrite f(g()) for multi-value g() during typecheck
This is a re-attempt at CL 153841, which caused two regressions:

1. crypto/ecdsa failed to build with -gcflags=-l=4. This was because
when "t1, t2, ... := g(); f(t1, t2, ...)" was exported, we were losing
the first assignment from the call's Ninit field.

2. net/http/pprof failed to run with -gcflags=-N. This is due to a
conflict with CL 159717: as of that CL, package-scope initialization
statements are executed within the "init.ializer" function, rather
than the "init" function, and the generated temp variables need to be
moved accordingly too.

[Rest of description is as before.]

This CL moves order.go's copyRet logic for rewriting f(g()) into t1,
t2, ... := g(); f(t1, t2, ...) earlier into typecheck. This allows the
rest of the compiler to stop worrying about multi-value functions
appearing outside of OAS2FUNC nodes.

This changes compiler behavior in a few observable ways:

1. Typechecking error messages for builtin functions now use general
case error messages rather than unnecessarily differing ones.

2. Because f(g()) is rewritten before inlining, saved inline bodies
now see the rewritten form too. This could be addressed, but doesn't
seem worthwhile.

3. Most notably, this simplifies escape analysis and fixes a memory
corruption issue in esc.go. See #29197 for details.

Fixes #15992.
Fixes #29197.

Change-Id: I930b10f7e27af68a0944d6c9bfc8707c3fab27a4
Reviewed-on: https://go-review.googlesource.com/c/go/+/166983
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-03-14 21:00:20 +00:00
Richard Musiol
5ee1b84959 math, math/bits: add intrinsics for wasm
This commit adds compiler intrinsics for the packages math and
math/bits on the wasm architecture for better performance.

benchmark                        old ns/op     new ns/op     delta
BenchmarkCeil                    8.31          3.21          -61.37%
BenchmarkCopysign                5.24          3.88          -25.95%
BenchmarkAbs                     5.42          3.34          -38.38%
BenchmarkFloor                   8.29          3.18          -61.64%
BenchmarkRoundToEven             9.76          3.26          -66.60%
BenchmarkSqrtLatency             8.13          4.88          -39.98%
BenchmarkSqrtPrime               5246          3535          -32.62%
BenchmarkTrunc                   8.29          3.15          -62.00%
BenchmarkLeadingZeros            13.0          4.23          -67.46%
BenchmarkLeadingZeros8           4.65          4.42          -4.95%
BenchmarkLeadingZeros16          7.60          4.38          -42.37%
BenchmarkLeadingZeros32          10.7          4.48          -58.13%
BenchmarkLeadingZeros64          12.9          4.31          -66.59%
BenchmarkTrailingZeros           6.52          4.04          -38.04%
BenchmarkTrailingZeros8          4.57          4.14          -9.41%
BenchmarkTrailingZeros16         6.69          4.16          -37.82%
BenchmarkTrailingZeros32         6.97          4.23          -39.31%
BenchmarkTrailingZeros64         6.59          4.00          -39.30%
BenchmarkOnesCount               7.93          3.30          -58.39%
BenchmarkOnesCount8              3.56          3.19          -10.39%
BenchmarkOnesCount16             4.85          3.19          -34.23%
BenchmarkOnesCount32             7.27          3.19          -56.12%
BenchmarkOnesCount64             8.08          3.28          -59.41%
BenchmarkRotateLeft              4.88          3.80          -22.13%
BenchmarkRotateLeft64            5.03          3.63          -27.83%

Change-Id: Ic1e0c2984878be8defb6eb7eb6ee63765c793222
Reviewed-on: https://go-review.googlesource.com/c/go/+/165177
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-03-14 19:46:19 +00:00
Josh Bleecher Snyder
61945fc502 cmd/compile: don't generate panicshift for masked int shifts
We know that a & 31 is non-negative for all a, signed or not.
We can avoid checking that and needing to write out an
unreachable call to panicshift.

Change-Id: I32f32fb2c950d2b2b35ac5c0e99b7b2dbd47f917
Reviewed-on: https://go-review.googlesource.com/c/go/+/167499
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
2019-03-14 00:03:29 +00:00
Josh Bleecher Snyder
870cfe6484 test/codegen: gofmt
Change-Id: I33f5b5051e5f75aa264ec656926223c5a3c09c1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/167498
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matt Layher <mdlayher@gmail.com>
2019-03-13 21:44:45 +00:00
Matthew Dempsky
a1b5cb1d04 cmd/compile: simplify isGoConst
The only ways to construct an OLITERAL node are (1) a basic literal
from the source package, (2) constant folding within evconst (which
only folds Go language constants), (3) the universal "nil" constant,
and (4) implicit conversions of nil to some concrete type.

Passes toolstash-check.

Change-Id: I30fc6b07ebede7adbdfa4ed562436cbb7078a2ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/166981
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-03-13 18:24:02 +00:00
Carlos Eduardo Seo
4ba69a9a17 cmd/compile: add processor level selection support to ppc64{,le}
ppc64{,le} processor level selection allows the compiler to generate instructions
targeting newer processors and processor-specific optimizations without breaking
compatibility with our current baseline. This feature introduces a new environment
variable, GOPPC64.

GOPPC64 is a GOARCH=ppc64{,le} specific option, for a choice between different
processor levels (i.e. Instruction Set Architecture versions) for which the
compiler will target. The default is 'power8'.

Change-Id: Ic152e283ae1c47084ece4346fa002a3eabb3bb9e
Reviewed-on: https://go-review.googlesource.com/c/go/+/163758
Run-TryBot: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2019-03-13 14:44:02 +00:00
Robert Griesemer
bea58ef352 cmd/compile: don't report redundant error for invalid integer literals
Fixes #30722.

Change-Id: Ia4c6e37282edc44788cd8af3f6cfa10895a19e4f
Reviewed-on: https://go-review.googlesource.com/c/go/+/166519
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2019-03-12 22:59:12 +00:00
Bryan C. Mills
af13cfc3a2 ../test: set GOPATH in nosplit.go
This test invokes 'go build', so in module mode it needs a module
cache to guard edits to go.mod.

Fixes #30776

Change-Id: I89ebef1fad718247e7f972cd830e31d6f4a83e4c
Reviewed-on: https://go-review.googlesource.com/c/go/+/167085
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-12 20:46:29 +00:00
fanzha02
a85afef277 cmd/compile: add handling for new floating-point comparisons flags
The CL 164718 adds new condition flags for floating-point comparisons
in arm64 backend, but dose not add the handling in rewrite.go for
corresponding Ops, which causes issue 30679. And this CL fixes this
issue.

Fixes #30679

Change-Id: I8acc749f78227c3e9e74fa7938f05fb442fb62c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/166579
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-12 14:01:26 +00:00
Than McIntosh
30cc8a46c4 test: add new test for gccgo compilation problem
New test for issue 30659 (compilation error due to bad
export data).

Updates #30659.

Change-Id: I2541ee3c379e5b22033fea66bb4ebaf720cc5e1f
Reviewed-on: https://go-review.googlesource.com/c/go/+/166917
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-03-12 00:04:59 +00:00
Keith Randall
486ca37b14 test: fix memcombine tests
Two tests (load_le_byte8_uint64_inv and load_be_byte8_uint64)
pass but the generated code isn't actually correct.

The test regexp provides a false negative, as it matches the
MOVQ (SP), BP instruction in the epilogue.

Combined loads never worked for these cases - the test was added in error
as part of a batch and not noticed because of the above false match.

Normalize the amd64/386 tests to always negative match on narrower
loads and OR.

Change-Id: I256861924774d39db0e65723866c81df5ab5076f
Reviewed-on: https://go-review.googlesource.com/c/go/+/166837
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-03-11 19:18:03 +00:00
Carlo Alberto Ferraris
05051b56a0 sync: allow inlining the RWMutex.RUnlock fast path
RWMutex.RLock is already inlineable, so add a test for it as well.

name                    old time/op  new time/op  delta
RWMutexUncontended      66.5ns ± 0%  60.3ns ± 1%  -9.38%  (p=0.000 n=12+20)
RWMutexUncontended-4    16.7ns ± 0%  15.3ns ± 1%  -8.49%  (p=0.000 n=17+20)
RWMutexUncontended-16   7.86ns ± 0%  7.69ns ± 0%  -2.08%  (p=0.000 n=18+15)
RWMutexWrite100         25.1ns ± 0%  24.0ns ± 1%  -4.28%  (p=0.000 n=20+18)
RWMutexWrite100-4       46.7ns ± 5%  44.1ns ± 4%  -5.53%  (p=0.000 n=20+20)
RWMutexWrite100-16      68.3ns ±11%  65.7ns ± 8%  -3.81%  (p=0.003 n=20+20)
RWMutexWrite10          26.7ns ± 1%  25.7ns ± 0%  -3.75%  (p=0.000 n=17+14)
RWMutexWrite10-4        34.9ns ± 2%  33.8ns ± 2%  -3.15%  (p=0.000 n=20+20)
RWMutexWrite10-16       37.4ns ± 2%  36.1ns ± 2%  -3.51%  (p=0.000 n=18+20)
RWMutexWorkWrite100      163ns ± 0%   162ns ± 0%  -0.89%  (p=0.000 n=18+20)
RWMutexWorkWrite100-4    189ns ± 4%   184ns ± 4%  -2.89%  (p=0.000 n=19+20)
RWMutexWorkWrite100-16   207ns ± 4%   200ns ± 2%  -3.07%  (p=0.000 n=19+20)
RWMutexWorkWrite10       153ns ± 0%   151ns ± 1%  -0.75%  (p=0.000 n=20+20)
RWMutexWorkWrite10-4     177ns ± 1%   176ns ± 2%  -0.63%  (p=0.004 n=17+20)
RWMutexWorkWrite10-16    191ns ± 2%   189ns ± 1%  -0.83%  (p=0.015 n=20+17)

linux/amd64 bin/go 14688201 (previous commit 14675861, +12340/+0.08%)

The cumulative effect of this and the previous 3 commits is:

name                    old time/op  new time/op  delta
MutexUncontended        19.3ns ± 1%  16.4ns ± 1%  -15.13%  (p=0.000 n=20+20)
MutexUncontended-4      5.24ns ± 0%  4.09ns ± 0%  -21.95%  (p=0.000 n=20+18)
MutexUncontended-16     2.10ns ± 0%  2.12ns ± 0%   +0.95%  (p=0.000 n=15+17)
Mutex                   19.6ns ± 0%  16.3ns ± 1%  -17.12%  (p=0.000 n=20+20)
Mutex-4                 54.6ns ± 5%  45.6ns ±10%  -16.51%  (p=0.000 n=20+19)
Mutex-16                 133ns ± 5%   130ns ± 3%   -1.99%  (p=0.002 n=20+20)
MutexSlack              33.4ns ± 2%  16.2ns ± 0%  -51.44%  (p=0.000 n=19+20)
MutexSlack-4             206ns ± 5%   209ns ± 9%     ~     (p=0.154 n=20+20)
MutexSlack-16           89.4ns ± 1%  90.9ns ± 2%   +1.70%  (p=0.000 n=18+17)
MutexWork               60.5ns ± 0%  55.3ns ± 1%   -8.59%  (p=0.000 n=12+20)
MutexWork-4              105ns ± 5%    97ns ±11%   -7.95%  (p=0.000 n=20+20)
MutexWork-16             157ns ± 1%   158ns ± 1%   +0.66%  (p=0.001 n=18+17)
MutexWorkSlack          70.2ns ± 5%  55.3ns ± 0%  -21.30%  (p=0.000 n=19+18)
MutexWorkSlack-4         277ns ±13%   260ns ±15%   -6.35%  (p=0.002 n=20+18)
MutexWorkSlack-16        156ns ± 0%   146ns ± 1%   -6.40%  (p=0.000 n=16+19)
MutexNoSpin              966ns ± 0%   976ns ± 1%   +0.97%  (p=0.000 n=15+17)
MutexNoSpin-4            269ns ± 4%   272ns ± 4%   +1.15%  (p=0.048 n=20+18)
MutexNoSpin-16           122ns ± 0%   119ns ± 1%   -2.63%  (p=0.000 n=19+15)
MutexSpin               3.13µs ± 0%  3.12µs ± 0%   -0.17%  (p=0.000 n=18+18)
MutexSpin-4              826ns ± 1%   833ns ± 1%   +0.84%  (p=0.000 n=19+17)
MutexSpin-16             397ns ± 1%   394ns ± 1%   -0.78%  (p=0.000 n=19+19)
Once                    5.67ns ± 0%  2.07ns ± 2%  -63.43%  (p=0.000 n=20+20)
Once-4                  1.47ns ± 2%  0.54ns ± 3%  -63.49%  (p=0.000 n=19+20)
Once-16                 0.58ns ± 0%  0.17ns ± 5%  -70.49%  (p=0.000 n=17+17)
RWMutexUncontended      71.4ns ± 0%  60.3ns ± 1%  -15.60%  (p=0.000 n=16+20)
RWMutexUncontended-4    18.4ns ± 4%  15.3ns ± 1%  -17.14%  (p=0.000 n=20+20)
RWMutexUncontended-16   8.01ns ± 0%  7.69ns ± 0%   -3.91%  (p=0.000 n=18+15)
RWMutexWrite100         24.9ns ± 0%  24.0ns ± 1%   -3.57%  (p=0.000 n=19+18)
RWMutexWrite100-4       46.5ns ± 3%  44.1ns ± 4%   -5.09%  (p=0.000 n=17+20)
RWMutexWrite100-16      68.9ns ± 3%  65.7ns ± 8%   -4.65%  (p=0.000 n=18+20)
RWMutexWrite10          27.1ns ± 0%  25.7ns ± 0%   -5.25%  (p=0.000 n=17+14)
RWMutexWrite10-4        34.8ns ± 1%  33.8ns ± 2%   -2.96%  (p=0.000 n=20+20)
RWMutexWrite10-16       37.5ns ± 2%  36.1ns ± 2%   -3.72%  (p=0.000 n=20+20)
RWMutexWorkWrite100      164ns ± 0%   162ns ± 0%   -1.49%  (p=0.000 n=12+20)
RWMutexWorkWrite100-4    186ns ± 3%   184ns ± 4%     ~     (p=0.097 n=20+20)
RWMutexWorkWrite100-16   204ns ± 2%   200ns ± 2%   -1.58%  (p=0.000 n=18+20)
RWMutexWorkWrite10       153ns ± 0%   151ns ± 1%   -1.21%  (p=0.000 n=20+20)
RWMutexWorkWrite10-4     179ns ± 1%   176ns ± 2%   -1.25%  (p=0.000 n=19+20)
RWMutexWorkWrite10-16    191ns ± 1%   189ns ± 1%   -0.94%  (p=0.000 n=15+17)

Change-Id: I9269bf2ac42a04c610624f707d3268dcb17390f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/152698
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-03-09 16:34:17 +00:00
Carlo Alberto Ferraris
ca8354843e sync: allow inlining the Once.Do fast path
Using Once.Do is now extremely cheap because the fast path is just an inlined
atomic load of a variable that is written only once and a conditional jump.
This is very beneficial for Once.Do because, due to its nature, the fast path
will be used for every call after the first one.

In a attempt to mimize code size increase, reorder the fields so that the
pointer to Once is also the pointer to Once.done, that is the only field used
in the hot path. This allows to use more compact instruction encodings or less
instructions in the hot path (that is inlined at every callsite).

name     old time/op  new time/op  delta
Once     4.54ns ± 0%  2.06ns ± 0%  -54.59%  (p=0.000 n=19+16)
Once-4   1.18ns ± 0%  0.55ns ± 0%  -53.39%  (p=0.000 n=15+16)
Once-16  0.53ns ± 0%  0.17ns ± 0%  -67.92%  (p=0.000 n=18+17)

linux/amd64 bin/go 14675861 (previous commit 14663387, +12474/+0.09%)

Change-Id: Ie2708103ab473787875d66746d2f20f1d90a6916
Reviewed-on: https://go-review.googlesource.com/c/go/+/152697
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-03-09 05:58:31 +00:00
Carlo Alberto Ferraris
41cb0aedff sync: allow inlining the Mutex.Lock fast path
name                    old time/op  new time/op  delta
MutexUncontended        18.9ns ± 0%  16.2ns ± 0%  -14.29%  (p=0.000 n=19+19)
MutexUncontended-4      4.75ns ± 1%  4.08ns ± 0%  -14.20%  (p=0.000 n=20+19)
MutexUncontended-16     2.05ns ± 0%  2.11ns ± 0%   +2.93%  (p=0.000 n=19+16)
Mutex                   19.3ns ± 1%  16.2ns ± 0%  -15.86%  (p=0.000 n=17+19)
Mutex-4                 52.4ns ± 4%  48.6ns ± 9%   -7.22%  (p=0.000 n=20+20)
Mutex-16                 139ns ± 2%   140ns ± 3%   +1.03%  (p=0.011 n=16+20)
MutexSlack              18.9ns ± 1%  16.2ns ± 1%  -13.96%  (p=0.000 n=20+20)
MutexSlack-4             225ns ± 8%   211ns ±10%   -5.94%  (p=0.000 n=18+19)
MutexSlack-16           98.4ns ± 1%  90.9ns ± 1%   -7.60%  (p=0.000 n=17+18)
MutexWork               58.2ns ± 3%  55.4ns ± 0%   -4.82%  (p=0.000 n=20+17)
MutexWork-4              103ns ± 7%    95ns ±18%   -8.03%  (p=0.000 n=20+20)
MutexWork-16             163ns ± 2%   155ns ± 2%   -4.47%  (p=0.000 n=18+18)
MutexWorkSlack          57.7ns ± 1%  55.4ns ± 0%   -3.99%  (p=0.000 n=20+13)
MutexWorkSlack-4         276ns ±13%   260ns ±10%   -5.64%  (p=0.001 n=19+19)
MutexWorkSlack-16        147ns ± 0%   156ns ± 1%   +5.87%  (p=0.000 n=14+19)
MutexNoSpin              968ns ± 0%   900ns ± 1%   -6.98%  (p=0.000 n=20+18)
MutexNoSpin-4            270ns ± 2%   255ns ± 2%   -5.74%  (p=0.000 n=19+20)
MutexNoSpin-16           120ns ± 4%   112ns ± 0%   -6.99%  (p=0.000 n=19+14)
MutexSpin               3.13µs ± 1%  3.19µs ± 6%     ~     (p=0.401 n=20+20)
MutexSpin-4              832ns ± 2%   831ns ± 1%   -0.17%  (p=0.023 n=16+18)
MutexSpin-16             395ns ± 0%   399ns ± 0%   +0.94%  (p=0.000 n=17+19)
RWMutexUncontended      69.5ns ± 0%  68.4ns ± 0%   -1.59%  (p=0.000 n=20+20)
RWMutexUncontended-4    17.5ns ± 0%  16.7ns ± 0%   -4.30%  (p=0.000 n=18+17)
RWMutexUncontended-16   7.92ns ± 0%  7.87ns ± 0%   -0.61%  (p=0.000 n=18+17)
RWMutexWrite100         24.9ns ± 1%  25.0ns ± 1%   +0.32%  (p=0.000 n=20+20)
RWMutexWrite100-4       46.2ns ± 4%  46.2ns ± 5%     ~     (p=0.840 n=19+20)
RWMutexWrite100-16      69.9ns ± 5%  69.9ns ± 3%     ~     (p=0.545 n=20+19)
RWMutexWrite10          27.0ns ± 2%  26.8ns ± 2%   -0.98%  (p=0.001 n=20+20)
RWMutexWrite10-4        34.7ns ± 2%  35.0ns ± 4%     ~     (p=0.191 n=18+20)
RWMutexWrite10-16       37.2ns ± 4%  37.3ns ± 2%     ~     (p=0.438 n=20+19)
RWMutexWorkWrite100      164ns ± 0%   163ns ± 0%   -0.24%  (p=0.025 n=20+20)
RWMutexWorkWrite100-4    193ns ± 3%   191ns ± 2%   -1.06%  (p=0.027 n=20+20)
RWMutexWorkWrite100-16   210ns ± 3%   207ns ± 3%   -1.22%  (p=0.038 n=20+20)
RWMutexWorkWrite10       153ns ± 0%   153ns ± 0%     ~     (all equal)
RWMutexWorkWrite10-4     178ns ± 2%   179ns ± 2%     ~     (p=0.186 n=20+20)
RWMutexWorkWrite10-16    192ns ± 2%   192ns ± 2%     ~     (p=0.731 n=19+20)

linux/amd64 bin/go 14663387 (previous commit 14630572, +32815/+0.22%)

Change-Id: I98171006dce14069b1a62da07c3d165455a7906b
Reviewed-on: https://go-review.googlesource.com/c/go/+/148959
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-03-09 05:08:04 +00:00
Keith Randall
83a33d3855 cmd/compile: reverse order of slice bounds checks
Turns out this makes the fix for 28797 unnecessary, because this order
ensures that the RHS of IsSliceInBounds ops are always nonnegative.

The real reason for this change is that it also makes dealing with
<0 values easier for reporting values in bounds check panics (issue #30116).

Makes cmd/go negligibly smaller.

Update #28797

Change-Id: I1f25ba6d2b3b3d4a72df3105828aa0a4b629ce85
Reviewed-on: https://go-review.googlesource.com/c/go/+/166377
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-09 00:52:45 +00:00
fanzha02
6efd51c6b7 cmd/compile: change the condition flags of floating-point comparisons in arm64 backend
Current compiler reverses operands to work around NaN in
"less than" and "less equal than" comparisons. But if we
want to use "FCMPD/FCMPS $(0.0), Fn" to do some optimization,
the workaround way does not work. Because assembler does
not support instruction "FCMPD/FCMPS Fn, $(0.0)".

This CL sets condition flags for floating-point comparisons
to resolve this problem.

Change-Id: Ia48076a1da95da64596d6e68304018cb301ebe33
Reviewed-on: https://go-review.googlesource.com/c/go/+/164718
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-03-07 21:23:52 +00:00
Raul Silvera
2dd066d4a7 test: improve test coverage for heap sampling
Update the test in test/heapsampling.go to more thoroughly validate heap sampling.
Lower the sampling rate on the test to ensure allocations both smaller and
larger than the sampling rate are tested.

Tighten up the validation check to a 10% difference between the unsampled and correct value.
Because of the nature of random sampling, it is possible that the unsampled value fluctuates
over that range. To avoid flakes, run the experiment three times and only report an issue if the
same location consistently falls out of range on all experiments.

This tests the sampling fix in cl/158337.

Change-Id: I54a709e5c75827b8b1c2d87cdfb425ab09759677
GitHub-Last-Rev: 7c04f12603
GitHub-Pull-Request: golang/go#26944
Reviewed-on: https://go-review.googlesource.com/c/go/+/129117
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-03-07 21:05:15 +00:00
erifan01
4e2b0dda8c cmd/compile: eliminate unnecessary type conversions in TrailingZeros(16|8) for arm64
This CL eliminates unnecessary type conversion operations: OpZeroExt16to64 and OpZeroExt8to64.
If the input argrument is a nonzero value, then ORconst operation can also be eliminated.

Benchmarks:

name               old time/op  new time/op  delta
TrailingZeros-8    2.75ns ± 0%  2.75ns ± 0%     ~     (all equal)
TrailingZeros8-8   3.49ns ± 1%  2.93ns ± 0%  -16.00%  (p=0.000 n=10+10)
TrailingZeros16-8  3.49ns ± 1%  2.93ns ± 0%  -16.05%  (p=0.000 n=9+10)
TrailingZeros32-8  2.67ns ± 1%  2.68ns ± 1%     ~     (p=0.468 n=10+10)
TrailingZeros64-8  2.67ns ± 1%  2.65ns ± 0%   -0.62%  (p=0.022 n=10+9)

code:

func f16(x uint) { z = bits.TrailingZeros16(uint16(x)) }

Before:

"".f16 STEXT size=48 args=0x8 locals=0x0 leaf
        0x0000 00000 (test.go:7)        TEXT    "".f16(SB), LEAF|NOFRAME|ABIInternal, $0-8
        0x0000 00000 (test.go:7)        FUNCDATA        ZR, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $3, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        PCDATA  $2, ZR
        0x0000 00000 (test.go:7)        PCDATA  ZR, ZR
        0x0000 00000 (test.go:7)        MOVD    "".x(FP), R0
        0x0004 00004 (test.go:7)        MOVHU   R0, R0
        0x0008 00008 (test.go:7)        ORR     $65536, R0, R0
        0x000c 00012 (test.go:7)        RBIT    R0, R0
        0x0010 00016 (test.go:7)        CLZ     R0, R0
        0x0014 00020 (test.go:7)        MOVD    R0, "".z(SB)
        0x0020 00032 (test.go:7)        RET     (R30)

This line of code is unnecessary:
        0x0004 00004 (test.go:7)        MOVHU   R0, R0

After:

"".f16 STEXT size=32 args=0x8 locals=0x0 leaf
        0x0000 00000 (test.go:7)        TEXT    "".f16(SB), LEAF|NOFRAME|ABIInternal, $0-8
        0x0000 00000 (test.go:7)        FUNCDATA        ZR, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $3, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        PCDATA  $2, ZR
        0x0000 00000 (test.go:7)        PCDATA  ZR, ZR
        0x0000 00000 (test.go:7)        MOVD    "".x(FP), R0
        0x0004 00004 (test.go:7)        ORR     $65536, R0, R0
        0x0008 00008 (test.go:7)        RBITW   R0, R0
        0x000c 00012 (test.go:7)        CLZW    R0, R0
        0x0010 00016 (test.go:7)        MOVD    R0, "".z(SB)
        0x001c 00028 (test.go:7)        RET     (R30)

The situation of TrailingZeros8 is similar to TrailingZeros16.

Change-Id: I473bdca06be8460a0be87abbae6fe640017e4c9d
Reviewed-on: https://go-review.googlesource.com/c/go/+/156999
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-07 14:24:56 +00:00
erifan01
fee84cc905 cmd/compile: add an optimization rule for math/bits.ReverseBytes16 on arm
This CL adds two rules to turn patterns like ((x<<8) | (x>>8)) (the type of
x is uint16, "|" can also be "+" or "^") to a REV16 instruction on arm v6+.
This optimization rule can be used for math/bits.ReverseBytes16.

Benchmarks on arm v6:
name               old time/op  new time/op  delta
ReverseBytes-32    2.86ns ± 0%  2.86ns ± 0%   ~     (all equal)
ReverseBytes16-32  2.86ns ± 0%  2.86ns ± 0%   ~     (all equal)
ReverseBytes32-32  1.29ns ± 0%  1.29ns ± 0%   ~     (all equal)
ReverseBytes64-32  1.43ns ± 0%  1.43ns ± 0%   ~     (all equal)

Change-Id: I819e633c9a9d308f8e476fb0c82d73fb73dd019f
Reviewed-on: https://go-review.googlesource.com/c/go/+/159019
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-07 13:37:54 +00:00
Keith Randall
9dc3b8b722 reflect: fix more issues with StructOf GC programs
First the insidious bug:

  var n uintptr
  for n := elemPtrs; n > 120; n -= 120 {
    prog = append(prog, 120)
    prog = append(prog, mask[:15]...)
    mask = mask[15:]
  }
  prog = append(prog, byte(n))
  prog = append(prog, mask[:(n+7)/8]...)

The := breaks this code, because the n after the loop is always 0!

We also do need to handle field padding correctly. In particular
the old padding code doesn't correctly handle fields that are not
a multiple of a pointer in size.

Fixes #30606.

Change-Id: Ifcab9494dc25c20116753c5d7e0145d6c2053ed8
Reviewed-on: https://go-review.googlesource.com/c/go/+/165860
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-03-07 00:06:12 +00:00
Keith Randall
05b3db24c1 reflect: fix StructOf GC programs
They are missing a stop byte at the end.

Normally this doesn't matter, but when including a GC program
in another GC program, we strip the last byte. If that last byte
wasn't a stop byte, then we've thrown away part of the program
we actually need.

Fixes #30606

Change-Id: Ie9604beeb84f7f9442e77d31fe64c374ca132cce
Reviewed-on: https://go-review.googlesource.com/c/go/+/165857
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-03-06 20:22:14 +00:00
Keith Randall
4a9064ef41 cmd/compile: fix ordering for short-circuiting ops
Make sure the side effects inside short-circuited operations (&& and ||)
happen correctly.

Before this CL, we attached the side effects to the node itself using
exprInPlace. That caused other side effects in sibling expressions
to get reordered with respect to the short circuit side effect.

Instead, rewrite a && b like:

r := a
if r {
  r = b
}

That code we can keep correctly ordered with respect to other
side-effects extracted from part of a big expression.

exprInPlace seems generally unsafe. But this was the only case where
exprInPlace is called not at the top level of an expression, so I
don't think the other uses can actually trigger an issue (there can't
be a sibling expression). TODO: maybe those cases don't need "in
place", and we can retire that function generally.

This CL needed a small tweak to the SSA generation of OIF so that the
short circuit optimization still triggers. The short circuit optimization
looks for triangle but not diamonds, so don't bother allocating a block
if it will be empty.

Go 1 benchmarks are in the noise.

Fixes #30566

Change-Id: I19c04296bea63cbd6ad05f87a63b005029123610
Reviewed-on: https://go-review.googlesource.com/c/go/+/165617
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2019-03-06 20:04:07 +00:00
Bryan C. Mills
b1a783df87 test/bench/go1: add go.mod file
cmd/dist executes 'go test' within this directory, so it needs a
go.mod file to tell the compiler what package path to use in
diagnostic and debug information.

Updates #30228

Change-Id: Ia313ac06bc0ec4631d415faa20c56cce2ac8dbc5
Reviewed-on: https://go-review.googlesource.com/c/go/+/165498
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-03-06 18:53:12 +00:00
Alberto Donizetti
2f8d2427d9 test: skip mutex Unlock inlining tests on a few builders
Fix builder breakage from CL 148958.

This is an inlining test that should be skipped on -N -l.

The inlining also doesn't happen on arm and wasm, so skip the test
there too.

Fixes the noopt builder, the linux-arm builder, and the wasm builder.

Updates #30605

Change-Id: I06b90d595be7185df61db039dd225dc90d6f678f
Reviewed-on: https://go-review.googlesource.com/c/go/+/165339
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-03-05 18:23:18 +00:00
Carlo Alberto Ferraris
4c3f26076b sync: allow inlining the Mutex.Unlock fast path
Make use of the newly-enabled limited midstack inlining.
Similar changes will be done in followup CLs.

name                    old time/op  new time/op  delta
MutexUncontended        19.3ns ± 1%  18.9ns ± 0%   -1.92%  (p=0.000 n=20+19)
MutexUncontended-4      5.24ns ± 0%  4.75ns ± 1%   -9.25%  (p=0.000 n=20+20)
MutexUncontended-16     2.10ns ± 0%  2.05ns ± 0%   -2.38%  (p=0.000 n=15+19)
Mutex                   19.6ns ± 0%  19.3ns ± 1%   -1.92%  (p=0.000 n=20+17)
Mutex-4                 54.6ns ± 5%  52.4ns ± 4%   -4.09%  (p=0.000 n=20+20)
Mutex-16                 133ns ± 5%   139ns ± 2%   +4.23%  (p=0.000 n=20+16)
MutexSlack              33.4ns ± 2%  18.9ns ± 1%  -43.56%  (p=0.000 n=19+20)
MutexSlack-4             206ns ± 5%   225ns ± 8%   +9.12%  (p=0.000 n=20+18)
MutexSlack-16           89.4ns ± 1%  98.4ns ± 1%  +10.10%  (p=0.000 n=18+17)
MutexWork               60.5ns ± 0%  58.2ns ± 3%   -3.75%  (p=0.000 n=12+20)
MutexWork-4              105ns ± 5%   103ns ± 7%   -1.68%  (p=0.007 n=20+20)
MutexWork-16             157ns ± 1%   163ns ± 2%   +3.90%  (p=0.000 n=18+18)
MutexWorkSlack          70.2ns ± 5%  57.7ns ± 1%  -17.81%  (p=0.000 n=19+20)
MutexWorkSlack-4         277ns ±13%   276ns ±13%     ~     (p=0.682 n=20+19)
MutexWorkSlack-16        156ns ± 0%   147ns ± 0%   -5.62%  (p=0.000 n=16+14)
MutexNoSpin              966ns ± 0%   968ns ± 0%   +0.11%  (p=0.029 n=15+20)
MutexNoSpin-4            269ns ± 4%   270ns ± 2%     ~     (p=0.807 n=20+19)
MutexNoSpin-16           122ns ± 0%   120ns ± 4%   -1.63%  (p=0.000 n=19+19)
MutexSpin               3.13µs ± 0%  3.13µs ± 1%   +0.16%  (p=0.004 n=18+20)
MutexSpin-4              826ns ± 1%   832ns ± 2%   +0.74%  (p=0.000 n=19+16)
MutexSpin-16             397ns ± 1%   395ns ± 0%   -0.50%  (p=0.000 n=19+17)
RWMutexUncontended      71.4ns ± 0%  69.5ns ± 0%   -2.72%  (p=0.000 n=16+20)
RWMutexUncontended-4    18.4ns ± 4%  17.5ns ± 0%   -4.92%  (p=0.000 n=20+18)
RWMutexUncontended-16   8.01ns ± 0%  7.92ns ± 0%   -1.15%  (p=0.000 n=18+18)
RWMutexWrite100         24.9ns ± 0%  24.9ns ± 1%     ~     (p=0.099 n=19+20)
RWMutexWrite100-4       46.5ns ± 3%  46.2ns ± 4%     ~     (p=0.253 n=17+19)
RWMutexWrite100-16      68.9ns ± 3%  69.9ns ± 5%   +1.46%  (p=0.012 n=18+20)
RWMutexWrite10          27.1ns ± 0%  27.0ns ± 2%     ~     (p=0.128 n=17+20)
RWMutexWrite10-4        34.8ns ± 1%  34.7ns ± 2%     ~     (p=0.180 n=20+18)
RWMutexWrite10-16       37.5ns ± 2%  37.2ns ± 4%   -0.89%  (p=0.023 n=20+20)
RWMutexWorkWrite100      164ns ± 0%   164ns ± 0%     ~     (p=0.106 n=12+20)
RWMutexWorkWrite100-4    186ns ± 3%   193ns ± 3%   +3.46%  (p=0.000 n=20+20)
RWMutexWorkWrite100-16   204ns ± 2%   210ns ± 3%   +2.96%  (p=0.000 n=18+20)
RWMutexWorkWrite10       153ns ± 0%   153ns ± 0%   -0.20%  (p=0.017 n=20+19)
RWMutexWorkWrite10-4     179ns ± 1%   178ns ± 2%     ~     (p=0.215 n=19+20)
RWMutexWorkWrite10-16    191ns ± 1%   192ns ± 2%     ~     (p=0.166 n=15+19)

linux/amd64 bin/go 14630572 (previous commit 14605947, +24625/+0.17%)

Change-Id: I3f9d1765801fe0b8deb1bc2728b8bba8a7508e23
Reviewed-on: https://go-review.googlesource.com/c/go/+/148958
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-03-05 14:59:31 +00:00
erifan01
159b2de442 cmd/compile: optimize math/bits.Div32 for arm64
Benchmark:
name     old time/op  new time/op  delta
Div-8    22.0ns ± 0%  22.0ns ± 0%     ~     (all equal)
Div32-8  6.51ns ± 0%  3.00ns ± 0%  -53.90%  (p=0.000 n=10+8)
Div64-8  22.5ns ± 0%  22.5ns ± 0%     ~     (all equal)

Code:
func div32(hi, lo, y uint32) (q, r uint32) {return bits.Div32(hi, lo, y)}

Before:
        0x0020 00032 (test.go:24)       MOVWU   "".y+8(FP), R0
        0x0024 00036 ($GOROOT/src/math/bits/bits.go:472)        CBZW    R0, 132
        0x0028 00040 ($GOROOT/src/math/bits/bits.go:472)        MOVWU   "".hi(FP), R1
        0x002c 00044 ($GOROOT/src/math/bits/bits.go:472)        CMPW    R1, R0
        0x0030 00048 ($GOROOT/src/math/bits/bits.go:472)        BLS     96
        0x0034 00052 ($GOROOT/src/math/bits/bits.go:475)        MOVWU   "".lo+4(FP), R2
        0x0038 00056 ($GOROOT/src/math/bits/bits.go:475)        ORR     R1<<32, R2, R1
        0x003c 00060 ($GOROOT/src/math/bits/bits.go:476)        CBZ     R0, 140
        0x0040 00064 ($GOROOT/src/math/bits/bits.go:476)        UDIV    R0, R1, R2
        0x0044 00068 (test.go:24)       MOVW    R2, "".q+16(FP)
        0x0048 00072 ($GOROOT/src/math/bits/bits.go:476)        UREM    R0, R1, R0
        0x0050 00080 (test.go:24)       MOVW    R0, "".r+20(FP)
        0x0054 00084 (test.go:24)       MOVD    -8(RSP), R29
        0x0058 00088 (test.go:24)       MOVD.P  32(RSP), R30
        0x005c 00092 (test.go:24)       RET     (R30)

After:
        0x001c 00028 (test.go:24)       MOVWU   "".y+8(FP), R0
        0x0020 00032 (test.go:24)       CBZW    R0, 92
        0x0024 00036 (test.go:24)       MOVWU   "".hi(FP), R1
        0x0028 00040 (test.go:24)       CMPW    R0, R1
        0x002c 00044 (test.go:24)       BHS     84
        0x0030 00048 (test.go:24)       MOVWU   "".lo+4(FP), R2
        0x0034 00052 (test.go:24)       ORR     R1<<32, R2, R4
        0x0038 00056 (test.go:24)       UDIV    R0, R4, R3
        0x003c 00060 (test.go:24)       MSUB    R3, R4, R0, R4
        0x0040 00064 (test.go:24)       MOVW    R3, "".q+16(FP)
        0x0044 00068 (test.go:24)       MOVW    R4, "".r+20(FP)
        0x0048 00072 (test.go:24)       MOVD    -8(RSP), R29
        0x004c 00076 (test.go:24)       MOVD.P  16(RSP), R30
        0x0050 00080 (test.go:24)       RET     (R30)

UREM instruction in the previous assembly code will be converted to UDIV and MSUB instructions
on arm64. However the UDIV instruction in UREM is unnecessary, because it's a duplicate of the
previous UDIV. This CL adds a rule to have this extra UDIV instruction removed by CSE.

Change-Id: Ie2508784320020b2de022806d09f75a7871bb3d7
Reviewed-on: https://go-review.googlesource.com/c/159577
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-03 20:20:10 +00:00
erifan01
192b675f17 cmd/compile: add an optimaztion rule for math/bits.ReverseBytes16 on arm64
On amd64 ReverseBytes16 is lowered to a rotate instruction. However arm64 doesn't
have 16-bit rotate instruction, but has a REV16W instruction which can be used
for ReverseBytes16. This CL adds a rule to turn the patterns like (x<<8) | (x>>8)
(the type of x is uint16, and "|" can also be "^" or "+") to a REV16W instruction.

Code:
func reverseBytes16(i uint16) uint16 { return bits.ReverseBytes16(i) }

Before:
        0x0004 00004 (test.go:6)        MOVHU   "".i(FP), R0
        0x0008 00008 ($GOROOT/src/math/bits/bits.go:262)        UBFX    $8, R0, $8, R1
        0x000c 00012 ($GOROOT/src/math/bits/bits.go:262)        ORR     R0<<8, R1, R0
        0x0010 00016 (test.go:6)        MOVH    R0, "".~r1+8(FP)
        0x0014 00020 (test.go:6)        RET     (R30)

After:
        0x0000 00000 (test.go:6)        MOVHU   "".i(FP), R0
        0x0004 00004 (test.go:6)        REV16W  R0, R0
        0x0008 00008 (test.go:6)        MOVH    R0, "".~r1+8(FP)
        0x000c 00012 (test.go:6)        RET     (R30)

Benchmarks:
name                old time/op       new time/op       delta
ReverseBytes-224    1.000000ns +- 0%  1.000000ns +- 0%     ~     (all equal)
ReverseBytes16-224  1.500000ns +- 0%  1.000000ns +- 0%  -33.33%  (p=0.000 n=9+10)
ReverseBytes32-224  1.000000ns +- 0%  1.000000ns +- 0%     ~     (all equal)
ReverseBytes64-224  1.000000ns +- 0%  1.000000ns +- 0%     ~     (all equal)

Change-Id: I87cd41b2d8e549bf39c601f185d5775bd42d739c
Reviewed-on: https://go-review.googlesource.com/c/157757
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-01 15:42:19 +00:00
Cherry Zhang
40df9cc606 cmd/compile: make KeepAlive work on stack object
Currently, runtime.KeepAlive applied on a stack object doesn't
actually keeps the stack object alive, and the heap object
referenced from it could be collected. This is because the
address of the stack object is rematerializeable, and we just
ignored KeepAlive on rematerializeable values. This CL fixes it.

Fixes #30476.

Change-Id: Ic1f75ee54ed94ea79bd46a8ddcd9e81d01556d1d
Reviewed-on: https://go-review.googlesource.com/c/164537
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-03-01 15:36:52 +00:00
Matthew Dempsky
38642b9fce Revert "cmd/compile: rewrite f(g()) for multi-value g() during typecheck"
This reverts commit d96b7fbf98.

Reason for revert: broke noopt and longtest builders.

Change-Id: Ifaec64d817c4336cb255a2e9db00526b7bc5606a
Reviewed-on: https://go-review.googlesource.com/c/164757
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-01 05:58:51 +00:00
Matthew Dempsky
d96b7fbf98 cmd/compile: rewrite f(g()) for multi-value g() during typecheck
This CL moves order.go's copyRet logic for rewriting f(g()) into t1,
t2, ... = g(); f(t1, t2, ...) earlier into typecheck. This allows the
rest of the compiler to stop worrying about multi-value functions
appearing outside of OAS2FUNC nodes.

This changes compiler behavior in a few observable ways:

1. Typechecking error messages for builtin functions now use general
case error messages rather than unnecessarily differing ones.

2. Because f(g()) is rewritten before inlining, saved inline bodies
now see the rewritten form too. This could be addressed, but doesn't
seem worthwhile.

3. Most notably, this simplifies escape analysis and fixes a memory
corruption issue in esc.go. See #29197 for details.

Fixes #15992.
Fixes #29197.

Change-Id: I86a70668301efeec8fbd11fe2d242e359a3ad0af
Reviewed-on: https://go-review.googlesource.com/c/153841
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-02-28 22:50:08 +00:00
Matthew Dempsky
7fa195c1b9 cmd/compile: fix false positives in isGoConst
isGoConst could spuriously return true for variables that shadow a
constant declaration with the same name.

Because even named constants are always represented by OLITERAL nodes,
the easy fix is to just ignore ONAME nodes in isGoConst. We can
similarly ignore ONONAME nodes.

Confirmed that k8s.io/kubernetes/test/e2e/storage builds again with
this fix.

Fixes #30430.

Change-Id: I899400d749982d341dc248a7cd5a18277c2795ec
Reviewed-on: https://go-review.googlesource.com/c/164319
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-02-28 20:31:53 +00:00
erifan01
dd91269b7c cmd/compile: optimize math/bits Len32 intrinsic on arm64
Arm64 has a 32-bit CLZ instruction CLZW, which can be used for intrinsic Len32.
Function LeadingZeros32 calls Len32, with this change, the assembly code of
LeadingZeros32 becomes more concise.

Go code:

func f32(x uint32) { z = bits.LeadingZeros32(x) }

Before:

"".f32 STEXT size=32 args=0x8 locals=0x0 leaf
        0x0000 00000 (test.go:7)        TEXT    "".f32(SB), LEAF|NOFRAME|ABIInternal, $0-8
        0x0004 00004 (test.go:7)        MOVWU   "".x(FP), R0
        0x0008 00008 ($GOROOT/src/math/bits/bits.go:30) CLZ     R0, R0
        0x000c 00012 ($GOROOT/src/math/bits/bits.go:30) SUB     $32, R0, R0
        0x0010 00016 (test.go:7)        MOVD    R0, "".z(SB)
        0x001c 00028 (test.go:7)        RET     (R30)

After:

"".f32 STEXT size=32 args=0x8 locals=0x0 leaf
        0x0000 00000 (test.go:7)        TEXT    "".f32(SB), LEAF|NOFRAME|ABIInternal, $0-8
        0x0004 00004 (test.go:7)        MOVWU   "".x(FP), R0
        0x0008 00008 ($GOROOT/src/math/bits/bits.go:30) CLZW    R0, R0
        0x000c 00012 (test.go:7)        MOVD    R0, "".z(SB)
        0x0018 00024 (test.go:7)        RET     (R30)

Benchmarks:
name              old time/op  new time/op  delta
LeadingZeros-8    2.53ns ± 0%  2.55ns ± 0%   +0.67%  (p=0.000 n=10+10)
LeadingZeros8-8   3.56ns ± 0%  3.56ns ± 0%     ~     (all equal)
LeadingZeros16-8  3.55ns ± 0%  3.56ns ± 0%     ~     (p=0.465 n=10+10)
LeadingZeros32-8  3.55ns ± 0%  2.96ns ± 0%  -16.71%  (p=0.000 n=10+7)
LeadingZeros64-8  2.53ns ± 0%  2.54ns ± 0%     ~     (p=0.059 n=8+10)

Change-Id: Ie5666bb82909e341060e02ffd4e86c0e5d67e90a
Reviewed-on: https://go-review.googlesource.com/c/157000
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-02-27 16:09:33 +00:00
Gergely Brautigam
8ee9bca272 cmd/compile: suppress typecheck errors in a type switch case with broken type
If a type switch case expression has failed typechecking, the case body is
likely to also fail with confusing or spurious errors. Suppress
typechecking the case body when this happens.

Fixes #28926

Change-Id: Idfdb9d5627994f2fd90154af1659e9a92bf692c4
Reviewed-on: https://go-review.googlesource.com/c/158617
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2019-02-27 08:22:03 +00:00
Matthew Dempsky
6fa7669fd7 cmd/compile: unify duplicate const detection logic
Consistent logic for handling both duplicate map keys and case values,
and eliminates ad hoc value hashing code.

Also makes cmd/compile consistent with go/types's handling of
duplicate constants (see #28085), which is at least an improvement
over the status quo even if we settle on something different for the
spec.

As a side effect, this also suppresses cmd/compile's warnings about
duplicate nils in (non-interface expression) switch statements, which
was technically never allowed by the spec anyway.

Updates #28085.
Updates #28378.

Change-Id: I176a251e770c3c5bc11c2bf8d1d862db8f252a17
Reviewed-on: https://go-review.googlesource.com/c/152544
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-02-27 01:08:13 +00:00
Iskander Sharipov
c1050a8e54 cmd/compile: don't generate newobject call for 0-sized types
Emit &runtime.zerobase instead of a call to newobject for
allocations of zero sized objects in walk.go.

Fixes #29446

Change-Id: I11b67981d55009726a17c2e582c12ce0c258682e
Reviewed-on: https://go-review.googlesource.com/c/155840
Run-TryBot: Iskander Sharipov <quasilyte@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2019-02-26 23:08:15 +00:00
Ian Lance Taylor
c3c90d0132 test: add test case that caused a gccgo compiler crash
Change-Id: Icdc980e0dcb5639c49aba5f4f252f33bd207e4fa
Reviewed-on: https://go-review.googlesource.com/c/162617
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-02-26 23:02:54 +00:00
Keith Randall
933e34ac99 cmd/compile: treat slice pointers as non-nil
var a []int = ...
p := &a[0]
_ = *p

We don't need to nil check on the 3rd line. If the bounds check on the 2nd
line passes, we know p is non-nil.

We rely on the fact that any cap>0 slice has a non-nil pointer as its
pointer to the backing array. This is true for all safely-constructed slices,
and I don't see any reason why someone would violate this rule using unsafe.

R=go1.13

Fixes #30366

Change-Id: I3ed764fcb72cfe1fbf963d8c1a82e24e3b6dead7
Reviewed-on: https://go-review.googlesource.com/c/163740
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2019-02-26 20:44:52 +00:00
Agniva De Sarker
39fa3f171c cmd/compile: fix a typo in assignment mismatch error
Fixes #30087

Change-Id: Ic6d80f8e6e1831886af8613420b1bd129a1b4850
Reviewed-on: https://go-review.googlesource.com/c/161577
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-02-26 18:50:48 +00:00
Michael Fraenkel
6d781decad cmd/compile: confusing error if composite literal field is a method
When looking for the field specified in a composite literal, check that
the specified name is actually a field and not a method.

Fixes #29855.

Change-Id: Id77666e846f925907b1eec64213b1d25af8a2466
Reviewed-on: https://go-review.googlesource.com/c/158938
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-02-26 18:42:07 +00:00
Bryan C. Mills
1670da9ee4 test: add a go.mod file in the working directory of nosplit.go
Updates #30228

Change-Id: I41bbedf15fa51242f69a3b1ecafd0d3191271799
Reviewed-on: https://go-review.googlesource.com/c/163518
Reviewed-by: Jay Conrod <jayconrod@google.com>
2019-02-26 02:44:45 +00:00
Cherry Zhang
0349f29a55 cmd/compile: flow interface data to heap if CONVIFACE of a non-direct interface escapes
Consider the following code:

func f(x []*T) interface{} {
	return x
}

It returns an interface that holds a heap copy of x (by calling
convT2I or friend), therefore x escape to heap. The current
escape analysis only recognizes that x flows to the result. This
is not sufficient, since if the result does not escape, x's
content may be stack allocated and this will result a
heap-to-stack pointer, which is bad.

Fix this by realizing that if a CONVIFACE escapes and we're
converting from a non-direct interface type, the data needs to
escape to heap.

Running "toolstash -cmp" on std & cmd, the generated machine code
are identical for all packages. However, the export data (escape
tags) differ in the following packages. It looks to me that all
are similar to the "f" above, where the parameter should escape
to heap.

io/ioutil/ioutil.go:118
	old: leaking param: r to result ~r1 level=0
	new: leaking param: r

image/image.go:943
	old: leaking param: p to result ~r0 level=1
	new: leaking param content: p

net/url/url.go:200
	old: leaking param: s to result ~r2 level=0
	new: leaking param: s

(as a consequence)
net/url/url.go:183
	old: leaking param: s to result ~r1 level=0
	new: leaking param: s

net/url/url.go:194
	old: leaking param: s to result ~r1 level=0
	new: leaking param: s

net/url/url.go:699
	old: leaking param: u to result ~r0 level=1
	new: leaking param: u

net/url/url.go:775
	old: (*URL).String u does not escape
	new: leaking param content: u

net/url/url.go:1038
	old: leaking param: u to result ~r0 level=1
	new: leaking param: u

net/url/url.go:1099
	old: (*URL).MarshalBinary u does not escape
	new: leaking param content: u

flag/flag.go:235
	old: leaking param: s to result ~r0 level=1
	new: leaking param content: s

go/scanner/errors.go:105
	old: leaking param: p to result ~r0 level=0
	new: leaking param: p

database/sql/sql.go:204
	old: leaking param: ns to result ~r0 level=0
	new: leaking param: ns

go/constant/value.go:303
	old: leaking param: re to result ~r2 level=0, leaking param: im to result ~r2 level=0
	new: leaking param: re, leaking param: im

go/constant/value.go:846
	old: leaking param: x to result ~r1 level=0
	new: leaking param: x

encoding/xml/xml.go:518
	old: leaking param: d to result ~r1 level=2
	new: leaking param content: d

encoding/xml/xml.go:122
	old: leaking param: leaking param: t to result ~r1 level=0
	new: leaking param: t

crypto/x509/verify.go:506
	old: leaking param: c to result ~r8 level=0
	new: leaking param: c

crypto/x509/verify.go:563
	old: leaking param: c to result ~r3 level=0, leaking param content: c
	new: leaking param: c

crypto/x509/verify.go:615
	old: (nothing)
	new: leaking closure reference c

crypto/x509/verify.go:996
	old: leaking param: c to result ~r1 level=0, leaking param content: c
	new: leaking param: c

net/http/filetransport.go:30
	old: leaking param: fs to result ~r1 level=0
	new: leaking param: fs

net/http/h2_bundle.go:2684
	old: leaking param: mh to result ~r0 level=2
	new: leaking param content: mh

net/http/h2_bundle.go:7352
	old: http2checkConnHeaders req does not escape
	new: leaking param content: req

net/http/pprof/pprof.go:221
	old: leaking param: name to result ~r1 level=0
	new: leaking param: name

cmd/internal/bio/must.go:21
	old: leaking param: w to result ~r1 level=0
	new: leaking param: w

Fixes #29353.

Change-Id: I7e7798ae773728028b0dcae5bccb3ada51189c68
Reviewed-on: https://go-review.googlesource.com/c/162829
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Chase <drchase@google.com>
2019-02-21 15:14:45 +00:00
Robert Griesemer
4ad5537bfa cmd/compile: accept 'i' suffix orthogonally on all numbers
This change accepts the 'i' suffix on binary and octal integer
literals as well as hexadecimal floats. The suffix was already
accepted on decimal integers and floats.

Note that 0123i == 123i for backward-compatibility (and 09i is
valid).

See also the respective language in the spec change:
https://golang.org/cl/161098

Change-Id: I9d2d755cba36a3fa7b9e24308c73754d4568daaf
Reviewed-on: https://go-review.googlesource.com/c/162878
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-02-19 22:45:09 +00:00
Robert Griesemer
041d31b882 cmd/compile: don't mix internal float/complex constants of different precision
There are several places where a new (internal) complex constant is allocated
via new(Mpcplx) rather than newMpcmplx(). The problem with using new() is that
the Mpcplx data structure's Real and Imag components don't get initialized with
an Mpflt of the correct precision (they have precision 0, which may be adjusted
later).

In all cases but one, the components of those complex constants are set using
a Set operation which "inherits" the correct precision from the value that is
being set.

But when creating a complex value for an imaginary literal, the imaginary
component is set via SetString which assumes 64bits of precision by default.
As a result, the internal representation of 0.01i and complex(0, 0.01) was
not correct.

Replaced all used of new(Mpcplx) with newMpcmplx() and added a new test.

Fixes #30243.

Change-Id: Ife7fd6ccd42bf887a55c6ce91727754657e6cb2d
Reviewed-on: https://go-review.googlesource.com/c/163000
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2019-02-19 21:05:17 +00:00
Cherry Zhang
dca707b2a0 cmd/compile: guard against loads with negative offset from readonly constants
CL 154057 adds guards agaist out-of-bound reads from readonly
constants. It turns out that in dead code, the offset can also
be negative. Guard against negative offset as well.

Fixes #30257.

Change-Id: I47c2a2e434dd466c08ae6f50f213999a358c796e
Reviewed-on: https://go-review.googlesource.com/c/162819
Reviewed-by: Keith Randall <khr@golang.org>
2019-02-16 02:02:31 +00:00
Keith Randall
585c9e8412 cmd/compile: implement shifts by signed amounts
Allow shifts by signed amounts. Panic if the shift amount is negative.

TODO: We end up doing two compares per shift, see Ian's comment
https://github.com/golang/go/issues/19113#issuecomment-443241799 that
we could do it with a single comparison in the normal case.

The prove pass mostly handles this code well. For instance, it removes the
<0 check for cases like this:
    if s >= 0 { _ = x << s }
    _ = x << len(a)

This case isn't handled well yet:
    _ = x << (y & 0xf)
I'll do followon CLs for unhandled cases as needed.

Update #19113

R=go1.13

Change-Id: I839a5933d94b54ab04deb9dd5149f32c51c90fa1
Reviewed-on: https://go-review.googlesource.com/c/158719
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2019-02-15 23:13:09 +00:00
Robert Griesemer
ceb849dd97 cmd/compile: accept new Go2 number literals
This CL introduces compiler support for the new binary and octal integer
literals, hexadecimal floats, and digit separators for all number literals.

The new Go 2 number literal scanner accepts the following liberal format:

number   = [ prefix ] digits [ "." digits ] [ exponent ] [ "i" ] .
prefix   = "0" [ "b" |"B" | "o" | "O" | "x" | "X" ] .
digits   = { digit | "_" } .
exponent = ( "e" | "E" | "p" | "P" ) [ "+" | "-" ] digits .

If the number starts with "0x" or "0X", digit is any hexadecimal digit;
otherwise, digit is any decimal digit. If the accepted number is not valid,
errors are reported accordingly.

See the new test cases in scanner_test.go for a selection of valid and
invalid numbers and the respective error messages.

R=Go1.13

Updates #12711.
Updates #19308.
Updates #28493.
Updates #29008.

Change-Id: Ic8febc7bd4dc5186b16a8c8897691e81125cf0ca
Reviewed-on: https://go-review.googlesource.com/c/157677
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2019-02-11 23:22:50 +00:00
Yasser Abdolmaleki
aa161ad17e test/chan: fix broken link to Squinting at Power Series
Change-Id: Idee94a1d93555d53442098dd7479982e3f5afbba
Reviewed-on: https://go-review.googlesource.com/c/161339
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-02-06 20:54:16 +00:00
Keith Randall
8f854244ad cmd/compile: fix crash when memmove argument is not the right type
Make sure the argument to memmove is of pointer type before we try to
get the element type.

This has been noticed for code that uses unsafe+linkname so it can
call runtime.memmove. Probably not the best thing to allow, but the
code is out there and we'd rather not break it unnecessarily.

Fixes #30061

Change-Id: I334a8453f2e293959fd742044c43fbe93f0b3d31
Reviewed-on: https://go-review.googlesource.com/c/160826
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-02-01 23:43:09 +00:00
Cherry Zhang
7e987b7b33 reflect: eliminate write barrier for copying result in callReflect
We are copying the results to uninitialized stack space. Write
barrier is not needed.

Fixes #30041.

Change-Id: Ia91d74dbafd96dc2bd92de0cb479808991dda03e
Reviewed-on: https://go-review.googlesource.com/c/160737
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2019-02-01 19:23:02 +00:00
Keith Randall
eafe9a186c cmd/compile: hide init functions in tracebacks
Treat compiler-generated init functions as wrappers, so they will not
be shown in tracebacks.

The exception to this rule is that we'd like to show the line number
of initializers for global variables in tracebacks. In order to
preserve line numbers for those cases, separate out the code for those
initializers into a separate function (which is not marked as
autogenerated).

This CL makes the go binary 0.2% bigger.

Fixes #29919

Change-Id: I0f1fbfc03d10d764ce3a8ddb48fb387ca8453386
Reviewed-on: https://go-review.googlesource.com/c/159717
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-01-27 04:02:46 +00:00
Ian Lance Taylor
d585f04fd3 cmd/compile: base PPC64 trunc rules on final type, not op type
Whether a truncation should become a MOVWreg or a MOVWZreg doesn't
depend on the type of the operand, it depends on the type of the final
result.  If the final result is unsigned, we can use MOVWZreg.  If the
final result is signed, we can use MOVWreg.  Checking the type of the
operand does the wrong thing if truncating an unsigned value to a
signed value, or vice-versa.

Fixes #29943

Change-Id: Ia6fc7d006486fa02cffd0bec4d910bdd5b6365f8
Reviewed-on: https://go-review.googlesource.com/c/159760
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-01-27 01:43:05 +00:00
Keith Randall
1fb596143c cmd/compile: don't bother compiling functions named "_"
They can't be used, so we don't need code generated for them. We just
need to report errors in their bodies.

This is the minimal CL for 1.12. For 1.13, CL 158845 will remove
a bunch of special cases sprinkled about the compiler to handle "_"
functions, which should (after this CL) be unnecessary.

Update #29870

Change-Id: Iaa1c194bd0017dffdce86589fe2d36726ee83c13
Reviewed-on: https://go-review.googlesource.com/c/158820
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-01-22 22:06:11 +00:00
Keith Randall
462e90259a runtime: keep FuncForPC from crashing for PCs between functions
Reuse the strict mechanism from FileLine for FuncForPC, so we don't
crash when asking the pcln table about bad pcs.

Fixes #29735

Change-Id: Iaffb32498b8586ecf4eae03823e8aecef841aa68
Reviewed-on: https://go-review.googlesource.com/c/157799
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-01-14 23:37:39 +00:00
Keith Randall
7502ed3b90 cmd/compile: when merging instructions, prefer line number of faulting insn
Normally this happens when combining a sign extension and a load.  We
want the resulting combo-instruction to get the line number of the
load, not the line number of the sign extension.

For each rule, compute where we should get its line number by finding
a value on the match side that can fault.  Use that line number for
all the new values created on the right-hand side.

Fixes #27201

Change-Id: I19b3c6f468fff1a3c0bfbce2d6581828557064a3
Reviewed-on: https://go-review.googlesource.com/c/156937
Reviewed-by: David Chase <drchase@google.com>
2019-01-14 22:41:33 +00:00
Austin Clements
a2e79571a9 cmd/compile: separate data and function LSyms
Currently, obj.Ctxt's symbol table does not distinguish between ABI0
and ABIInternal symbols. This is *almost* okay, since a given symbol
name in the final object file is only going to belong to one ABI or
the other, but it requires that the compiler mark a Sym as being a
function symbol before it retrieves its LSym. If it retrieves the LSym
first, that LSym will be created as ABI0, and later marking the Sym as
a function symbol won't change the LSym's ABI.

Marking a Sym as a function symbol before looking up its LSym sounds
easy, except Syms have a dual purpose: they are used just as interned
strings (every function, variable, parameter, etc with the same
textual name shares a Sym), and *also* to store state for whatever
package global has that name. As a result, it's easy to slip up and
look up an LSym when a Sym is serving as the name of a local variable,
and then later mark it as a function when it's serving as the global
with the name.

In general, we were careful to avoid this, but #29610 demonstrates one
case where we messed up. Because of on-demand importing from indexed
export data, it's possible to compile a method wrapper for a type
imported from another package before importing an init function from
that package. If the argument of the method is named "init", the
"init" LSym will be created as a data symbol when compiling the
wrapper, before it gets marked as a function symbol.

To fix this, we separate obj.Ctxt's symbol tables for ABI0 and
ABIInternal symbols. This way, the compiler will simply get a
different LSym once the Sym takes on its package-global meaning as a
function.

This fixes the above ordering issue, and means we no longer need to go
out of our way to create the "init" function early and mark it as a
function symbol.

Fixes #29610.
Updates #27539.

Change-Id: Id9458b40017893d46ef9e4a3f9b47fc49e1ce8df
Reviewed-on: https://go-review.googlesource.com/c/157017
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-01-11 00:45:49 +00:00
Keith Randall
956879dd0b runtime: make FuncForPC return the innermost inlined frame
Returning the innermost frame instead of the outermost
makes code that walks the results of runtime.Caller{,s}
still work correctly in the presence of mid-stack inlining.

Fixes #29582

Change-Id: I2392e3dd5636eb8c6f58620a61cef2194fe660a7
Reviewed-on: https://go-review.googlesource.com/c/156364
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-01-08 21:54:04 +00:00
David Chase
28fb8c6987 cmd/compile: modify swt.go to skip repeated walks of switch
The compiler appears to contain several squirrelly corner
cases where nodes are double walked, some where new nodes
are created from walked parts.  Rather than trust that we
had searched hard enough for the last one, change
exprSwitch.walk() to return immediately if it has already
been walked.  This appears to be the only case where
double-walking a node is actually harmful.

Fixes #29562.

Change-Id: I0667e8769aba4c3236666cd836a934e256c0bfc5
Reviewed-on: https://go-review.googlesource.com/c/156317
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-01-04 21:51:37 +00:00
Keith Randall
af134b17da runtime: proper panic tracebacks with mid-stack inlining
As a followon to CL 152537, modify the panic-printing traceback
to also handle mid-stack inlining correctly.

Also declare -fm functions (aka method functions) as wrappers, so that
they get elided during traceback. This fixes part 2 of #26839.

Fixes #28640
Fixes #24488
Update #26839

Change-Id: I1c535a9b87a9a1ea699621be1e6526877b696c21
Reviewed-on: https://go-review.googlesource.com/c/153477
Reviewed-by: David Chase <drchase@google.com>
2019-01-04 00:00:24 +00:00
Keith Randall
688667716e runtime: don't scan go'd function args past length of ptr bitmap
Use the length of the bitmap to decide how much to pass to the
write barrier, not the total length of the arguments.

The test needs enough arguments so that two distinct bitmaps
get interpreted as a single longer bitmap.

Update #29362

Change-Id: I78f3f7f9ec89c2ad4678f0c52d3d3def9cac8e72
Reviewed-on: https://go-review.googlesource.com/c/156123
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-01-03 23:37:42 +00:00
Keith Randall
af4320350b runtime: add test for go function argument scanning
Derived	from Naoki's reproducer.

Update #29362

Change-Id: I1cbd33b38a2f74905dbc22c5ecbad4a87a24bdd1
Reviewed-on: https://go-review.googlesource.com/c/156122
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-01-03 20:17:01 +00:00
Cherry Zhang
2e217fa726 cmd/compile: fix deriving from x+d >= w on overflow in prove pass
In the case of x+d >= w, where d and w are constants, we are
deriving x is within the bound of min=w-d and max=maxInt-d. When
there is an overflow (min >= max), we know only one of x >= min
or x <= max is true, and we derive this by excluding the other.
When excluding x >= min, we did not consider the equal case, so
we could incorrectly derive x <= max when x == min.

Fixes #29502.

Change-Id: Ia9f7d814264b1a3ddf78f52e2ce23377450e6e8a
Reviewed-on: https://go-review.googlesource.com/c/156019
Reviewed-by: David Chase <drchase@google.com>
2019-01-02 19:28:06 +00:00
Alberto Donizetti
efbd01f1dc test: disable issue 29329 test when cgo is not enabled
CL 155917 added a -race test that shouldn't be run when cgo is not
enabled. Enforce this in the test file, with a buildflag.

Fixes the nocgo builder.

Change-Id: I9fe0d8f21da4d6e2de3f8fe9395e1fa7e9664b02
Reviewed-on: https://go-review.googlesource.com/c/155957
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-12-29 14:18:11 +00:00
Keith Randall
ed15e82413 runtime: panic on uncomparable map key, even if map is empty
Reorg map flags a bit so we don't need any extra space for the extra flag.

Fixes #23734

Change-Id: I436812156240ae90de53d0943fe1aabf3ea37417
Reviewed-on: https://go-review.googlesource.com/c/155918
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-12-29 01:00:54 +00:00
Keith Randall
14bdcc76fd cmd/compile: fix racewalk{enter,exit} removal
We can't remove race instrumentation unless there are no calls,
not just no static calls. Closure and interface calls also count.

The problem in issue 29329 is that there was a racefuncenter, an
InterCall, and a racefuncexit.  The racefuncenter was removed, then
the InterCall was rewritten to a StaticCall. That prevented the
racefuncexit from being removed. That caused an imbalance in
racefuncenter/racefuncexit calls, which made the race detector barf.

Bug introduced at CL 121235

Fixes #29329

Change-Id: I2c94ac6cf918dd910b74b2a0de5dc2480d236f16
Reviewed-on: https://go-review.googlesource.com/c/155917
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-12-29 00:04:59 +00:00
Keith Randall
69c2c56453 cmd/compile,runtime: redo mid-stack inlining tracebacks
Work involved in getting a stack trace is divided between
runtime.Callers and runtime.CallersFrames.

Before this CL, runtime.Callers returns a pc per runtime frame.
runtime.CallersFrames is responsible for expanding a runtime frame
into potentially multiple user frames.

After this CL, runtime.Callers returns a pc per user frame.
runtime.CallersFrames just maps those to user frame info.

Entries in the result of runtime.Callers are now pcs
of the calls (or of the inline marks), not of the instruction
just after the call.

Fixes #29007
Fixes #28640
Update #26320

Change-Id: I1c9567596ff73dc73271311005097a9188c3406f
Reviewed-on: https://go-review.googlesource.com/c/152537
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2018-12-28 20:55:36 +00:00
Cherry Zhang
6a64efc250 cmd/compile: fix MIPS SGTconst-with-shift rules
(SGTconst [c] (SRLconst _ [d])) && 0 <= int32(c) && uint32(d) <= 31 && 1<<(32-uint32(d)) <= int32(c) -> (MOVWconst [1])

This rule is problematic. 1<<(32-uint32(d)) <= int32(c) meant to
say that it is true if c is greater than the largest possible
value of the right shift. But when d==1, 1<<(32-1) is negative
and results in the wrong comparison.

Rewrite the rules in a more direct way.

Fixes #29402.

Change-Id: I5940fc9538d9bc3a4bcae8aa34672867540dc60e
Reviewed-on: https://go-review.googlesource.com/c/155798
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-12-27 00:07:53 +00:00
Keith Randall
c5414457c6 cmd/compile: pad zero-sized stack variables
If someone takes a pointer to a zero-sized stack variable, it can
be incorrectly interpreted as a pointer to the next object in the
stack frame. To avoid this, add some padding after zero-sized variables.

We only need to pad if the next variable in memory (which is the
previous variable in the order in which we allocate variables to the
stack frame) has pointers. If the next variable has no pointers, it
won't hurt to have a pointer to it.

Because we allocate all pointer-containing variables before all
non-pointer-containing variables, we should only have to pad once per
frame.

Fixes #24993

Change-Id: Ife561cdfdf964fdbf69af03ae6ba97d004e6193c
Reviewed-on: https://go-review.googlesource.com/c/155698
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-12-22 01:16:00 +00:00
Keith Randall
debca77971 cmd/compile: fix line number for implicitly declared method expressions
Method expressions where the method is implicitly declared have no
line number. The Error method of the built-in error type is one such
method.  We leave the line number at the use of the method expression
in this case.

Fixes #29389

Change-Id: I29c64bb47b1a704576abf086599eb5af7b78df53
Reviewed-on: https://go-review.googlesource.com/c/155639
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-12-22 01:08:39 +00:00
Matthew Dempsky
706b54bb85 cmd/compile: fix ICE due to bad rune width
It was possible that

    var X interface{} = 'x'

could cause a compilation failure due to having not calculated rune's
width yet. typecheck.go normally calculates the width of things, but
it doesn't for implicit conversions to default type. We already
compute the width of all of the standard numeric types in universe.go,
but we failed to calculate it for the rune alias type. So we could
later crash if the code never otherwise explicitly mentioned 'rune'.

While here, explicitly compute widths for 'byte' and 'error' for
consistency.

Fixes #29350.

Change-Id: Ifedd4899527c983ee5258dcf75aaf635b6f812f8
Reviewed-on: https://go-review.googlesource.com/c/155380
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-12-20 19:35:04 +00:00
Keith Randall
443990742e cmd/compile: ignore out-of-bounds reads from readonly constants
Out-of-bounds reads of globals can happen in dead code. For code
like this:

s := "a"
if len(s) == 3 {
   load s[0], s[1], and s[2]
}

The out-of-bounds loads are dead code, but aren't removed yet
when lowering. We need to not panic when compile-time evaluating
those loads. This can only happen for dead code, so the result
doesn't matter.

Fixes #29215

Change-Id: I7fb765766328b9524c6f2a1e6ab8d8edd9875097
Reviewed-on: https://go-review.googlesource.com/c/154057
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alberto Donizetti <alb.donizetti@gmail.com>
2018-12-20 17:34:32 +00:00
Robert Griesemer
99e4ddd053 cmd/compile: increase nesting depth limit for type descriptors
The formatting routines for types use a depth limit as primitive
mechanism to detect cycles. For now, increase the limit from 100
to 250 and file #29312 so we don't drop this on the floor.

Also, adjust some fatal error messages elsewhere to use
better formatting.

Fixes #29264.
Updates #29312.

Change-Id: Idd529f6682d478e0dcd2d469cb802192190602f6
Reviewed-on: https://go-review.googlesource.com/c/154583
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-12-18 00:13:58 +00:00
David Chase
d924c3336c cmd/compile: prevent double-walk of switch for OPRINT/OPRINTN
When a println arg contains a call to an inlineable function
that itself contains a switch, that switch statement will be
walked twice, once by the walkexprlist formerly in the
OPRINT/OPRINTN case, then by walkexprlistcheap in walkprint.

Remove the first walkexprlist, it is not necessary.
walkexprlist =
		s[i] = walkexpr(s[i], init)
walkexprlistcheap = {
		s[i] = cheapexpr(n, init)
		s[i] = walkexpr(s[i], init)
}

Seems like this might be possible in other places, i.e.,
calls to inlineable switch-containing functions.

See also #25776.
Fixes #29220.

Change-Id: I3781e86aad6688711597b8bee9bc7ebd3af93601
Reviewed-on: https://go-review.googlesource.com/c/154497
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-12-17 22:49:21 +00:00
Robert Griesemer
a1aafd8b28 cmd/compile: generate interface method expression wrapper for error.Error
A prior optimization (https://golang.org/cl/106175) removed the
generation of unnecessary method expression wrappers, but also
eliminated the generation of the wrapper for error.Error which
was still required.

Special-case error type in the optimization.

Fixes #29304.

Change-Id: I54c8afc88a2c6d1906afa2d09c68a0a3f3e2f1e3
Reviewed-on: https://go-review.googlesource.com/c/154578
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-12-17 19:48:36 +00:00
Martin Möhrmann
38e7177c94 cmd/compile: fix length overflow when appending elements to a slice
Instead of testing len(slice)+numNewElements > cap(slice) use
uint(len(slice)+numNewElements) > uint(cap(slice)) to test
if a slice needs to be grown in an append operation.

This prevents a possible overflow when len(slice) is near the maximum
int value and the addition of a constant number of new elements
makes it overflow and wrap around to a negative number which is
smaller than the capacity of the slice.

Appending a slice to a slice with append(s1, s2...) already used
a uint comparison to test slice capacity and therefore was not
vulnerable to the same overflow issue.

Fixes: #29190

Change-Id: I41733895838b4f80a44f827bf900ce931d8be5ca
Reviewed-on: https://go-review.googlesource.com/c/154037
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-12-14 05:48:18 +00:00
Keith Randall
05bbec7357 cmd/compile: don't combine load+op if the op has SymAddr arguments
By combining the load+op, we may force the op to happen earlier in
the store chain. That might force the SymAddr operation earlier, and
in particular earlier than its corresponding VarDef. That leads to
an invalid schedule, so avoid that.

This is kind of a hack to work around the issue presented. I think
the underlying problem, that LEAQ is not directly ordered with respect
to its vardef, is the real problem. The benefit of this CL is that
it fixes the immediate issue, is small, and obviously won't break
anything. A real fix for this issue is much more invasive.

The go binary is unchanged in size.
This situation just doesn't occur very often.

Fixes #28445

Change-Id: I13a765e13f075d5b6808a355ef3c43cdd7cd47b6
Reviewed-on: https://go-review.googlesource.com/c/153641
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-12-12 21:13:15 +00:00
Keith Randall
01a1eaa10c cmd/compile: use innermost line number for -S
When functions are inlined, for instructions in the inlined body, does
-S print the location of the call, or the location of the body? Right
now, we do the former. I'd like to do the latter by default, it makes
much more sense when reading disassembly. With mid-stack inlining
enabled in more cases, this quandry will come up more often.

The original behavior is still available with -S=2. Some tests
use this mode (so they can find assembly generated by a particular
source line).

This helped me with understanding what the compiler was doing
while fixing #29007.

Change-Id: Id14a3a41e1b18901e7c5e460aa4caf6d940ed064
Reviewed-on: https://go-review.googlesource.com/c/153241
Reviewed-by: David Chase <drchase@google.com>
2018-12-11 20:24:45 +00:00
David Chase
ea6259d5e9 cmd/compile: check for negative upper bound to IsSliceInBounds
IsSliceInBounds(x, y) asserts that y is not negative, but
there were cases where this is not true.  Change code
generation to ensure that this is true when it's not obviously
true.  Prove phase cleans a few of these out.

With this change the compiler text section is 0.06% larger,
that is, not very much.  Benchmarking still TBD, may need
to wait for access to a benchmarking box (next week).

Also corrected run.go to handle '?' in -update_errors output.

Fixes #28797.

Change-Id: Ia8af90bc50a91ae6e934ef973def8d3f398fac7b
Reviewed-on: https://go-review.googlesource.com/c/152477
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-12-07 23:04:58 +00:00
Austin Clements
6454a09a97 cmd/compile: omit write barriers for slice clears of go:notinheap pointers
Currently,

  for i := range a {
    a[i] = nil
  }

will compile to have write barriers even if a is a slice of pointers
to go:notinheap types. This happens because the optimization that
transforms this into a memclr only asks it a's element type has
pointers, and not if it specifically has heap pointers.

Fix this by changing arrayClear to use HasHeapPointer instead of
types.Haspointers. We probably shouldn't have both of these functions,
since a pointer to a notinheap type is effectively a uintptr, but
that's not going to change in this CL.

Change-Id: I284b85bdec6ae1e641f894e8f577989facdb0cf1
Reviewed-on: https://go-review.googlesource.com/c/152723
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-12-05 21:54:54 +00:00
Robert Griesemer
cd47e8944d cmd/compile: avoid multiple errors regarding misuse of ... in signatures
Follow-up on #28450 (golang.org/cl/152417).

Updates #28450.
Fixes #29107.

Change-Id: Ib4b4fe582c35315a4f71cf6dbc7f7f2f24b37ec1
Reviewed-on: https://go-review.googlesource.com/c/152758
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-12-05 20:59:58 +00:00
smasher164
a7af474359 cmd/compile: improve error message for non-final variadic parameter
Previously, when a function signature had defined a non-final variadic
parameter, the error message always referred to the type associated with that
parameter. However, if the offending parameter's name was part of an identifier
list with a variadic type, one could misinterpret the message, thinking the
problem had been with one of the other names in the identifer list.

    func bar(a, b ...int) {}
clear ~~~~~~~^       ^~~~~~~~ confusing

This change updates the error message and sets the column position to that of
the offending parameter's name, if it exists.

Fixes #28450.

Change-Id: I076f560925598ed90e218c25d70f9449ffd9b3ea
Reviewed-on: https://go-review.googlesource.com/c/152417
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-12-05 01:35:59 +00:00
Cherry Zhang
be09bdf589 cmd/compile: fix unnamed parameter handling in escape analysis
For recursive functions, the parameters were iterated using
fn.Name.Defn.Func.Dcl, which does not include unnamed/blank
parameters. This results in a mismatch in formal-actual
assignments, for example,

func f(_ T, x T)

f(a, b) should result in { _=a, x=b }, but the escape analysis
currently sees only { x=a } and drops b on the floor. This may
cause b to not escape when it should (or a escape when it should
not).

Fix this by using fntype.Params().FieldSlice() instead, which
does include unnamed parameters.

Also add a sanity check that ensures all the actual parameters
are consumed.

Fixes #29000

Change-Id: Icd86f2b5d71e7ebbab76e375b7702f62efcf59ae
Reviewed-on: https://go-review.googlesource.com/c/152617
Reviewed-by: Keith Randall <khr@golang.org>
2018-12-04 23:01:00 +00:00