Commit Graph

4501 Commits

Author SHA1 Message Date
Russ Cox 768201729d cmd/compile: detect and diagnose invalid //go: directive placement
Thie CL changes cmd/compile/internal/syntax to give the gc half of
the compiler more control over pragma handling, so that it can prepare
better errors, diagnose misuse, and so on. Before, the API between
the two was hard-coded as a uint16. Now it is an interface{}.
This should set us up better for future directives.

In addition to the split, this CL emits a "misplaced compiler directive"
error for any directive that is in a place where it has no effect.
I've certainly been confused in the past by adding comments
that were doing nothing and not realizing it. This should help
avoid that kind of confusion.

The rule, now applied consistently, is that a //go: directive
must appear on a line by itself immediately before the declaration
specifier it means to apply to. See cmd/compile/doc.go for
precise text and test/directive.go for examples.

This may cause some code to stop compiling, but that code
was broken. For example, this code formerly applied the
//go:noinline to f (not c) but now will fail to compile:

	//go:noinline
	const c = 1

	func f() {}

Change-Id: Ieba9b8d90a27cfab25de79d2790a895cefe5296f
Reviewed-on: https://go-review.googlesource.com/c/go/+/228578
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2020-04-21 16:47:01 +00:00
Alberto Donizetti 17fbc818ff cmd/compile: switch to typed aux for 386 optimization rules
Convert first section of 386 optimization rules to the typed aux form.

Adds addOffset{32,64} functions that returns ValAndOffs and a
ValAndOff.canAdd32 function that takes an int32.

Passes

  GOARCH=386 gotip build -toolexec 'toolstash -cmp' -a std

Change-Id: I69d2a8ace6936d5e8ba6ba047183002bf07dd5be
Reviewed-on: https://go-review.googlesource.com/c/go/+/228825
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-21 08:08:49 +00:00
Josh Bleecher Snyder 4974ac6874 cmd/compile: use cheaper implementation of oneBit
This is the second attempt. The first attempt was CL 229127,
which got rolled back by CL 229177, because it caused
an infinite loop during compilation on some platforms.
I didn't notice that the trybots hadn't completed when I submitted; mea culpa.

The bug was that we were checking x&(x-1)==0, which is also true of 0,
which does not have exactly one bit set.
This caused an infinite rewrite rule loop.

Updates #38547

file    before    after     Δ       %
compile 19678112  19669808  -8304   -0.042%
total   113143160 113134856 -8304   -0.007%

Change-Id: I417a4f806e1ba61277e31bab2e57dd3f1ac7e835
Reviewed-on: https://go-review.googlesource.com/c/go/+/229197
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
2020-04-21 05:56:02 +00:00
Josh Bleecher Snyder 9255163091 Revert "cmd/compile: use cheaper implementation of oneBit"
This reverts commit 066c47ca5f.

Reason for revert: This appears to have broken a bunch of builders.

Change-Id: I68b4decf3c1892766e195d8eb018844cdff69443
Reviewed-on: https://go-review.googlesource.com/c/go/+/229177
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2020-04-21 04:28:59 +00:00
Cuong Manh Le 7f8fda3c0b cmd/compile: use proper magnitude for (x>>c) & uppermask = 0
This is followup of CL 228860, which rewrite shift rules to use typed
aux. That CL introduced nlz* functions, to refactor left shift rules.
While at it, we realize there's a bug in old rules with both right/left
shift rules, but only fix for left shift rules only.

This CL fixes the bug for right shift rules.

Passes toolstash-check.

Change-Id: Id8f2158b1b66c9e87f3fdeaa7ae3e35dc0666f8b
Reviewed-on: https://go-review.googlesource.com/c/go/+/229137
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-21 03:45:26 +00:00
Cuong Manh Le 0f14c2a042 cmd/compile: rewrite shift rules to use typed aux fields
Passes toolstash-check.

Change-Id: I02e78591fe46e19a43dc36913baef0338a014a3d
Reviewed-on: https://go-review.googlesource.com/c/go/+/228860
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-21 03:13:22 +00:00
Josh Bleecher Snyder 066c47ca5f cmd/compile: use cheaper implementation of oneBit
Updates #38547

file    before    after     Δ       %       
compile 19678112  19669808  -8304   -0.042% 
total   113143160 113134856 -8304   -0.007% 

Change-Id: I5f8afe17401dbdb7c7b3d66d95fe40821c499a92
Reviewed-on: https://go-review.googlesource.com/c/go/+/229127
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2020-04-21 00:38:53 +00:00
Josh Bleecher Snyder 50b11318fe cmd/compile: use oneBit instead of isPowerOfTwo in bit optimization
This optimization works on any integer with exactly one bit set.
This is identical to being a power of two, except in the
most negative number. Use oneBit instead.

The rule now triggers in a few more places in std+cmd,
in packages encoding/asn1, crypto/elliptic, and
vendor/golang.org/x/crypto/cryptobyte.

This change obviates the need for CL 222479
by doing this optimization consistently in the compiler.

Change-Id: I983c6235290fdc634fda5e11b10f1f8ce041272f
Reviewed-on: https://go-review.googlesource.com/c/go/+/229124
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2020-04-21 00:38:34 +00:00
Josh Bleecher Snyder 12665b9a06 cmd/compile: convert two generic rules to be typed
Prelude to changing the rules.

Passes toolstash-check.

Change-Id: I22fead7f74d2cf97bb3fbeb22741125b42914c43
Reviewed-on: https://go-review.googlesource.com/c/go/+/229123
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2020-04-21 00:38:14 +00:00
David Finkel 1cca496c5e Revert "Revert "cmd/compile: adjust RISCV64 rewrite rules to use typed aux fields""
This reverts commit 98c32670fd454939794504225dca1d4ec55045d5.

Rolling-forward with trivial format-string fix

cmd/compile: adjust RISCV64 rewrite rules to use typed aux fields

Also add a typed version of mergeSym to rewrite.go to assist with a few
rules that used mergeSym in the untyped-form.

Remove a few extra int32 overflow checks that no longer make sense, as
adding two int8s or int16s should never overflow an int32.

Passes toolstash-check -all.

Original review: https://go-review.googlesource.com/c/go/+/228882

Change-Id: Ib63db4ee1687446f0f3d9f11575a40dd85cbce55
Reviewed-on: https://go-review.googlesource.com/c/go/+/229126
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-04-20 23:30:29 +00:00
Than McIntosh 0cffc95109 Revert "cmd/compile: adjust RISCV64 rewrite rules to use typed aux fields"
This reverts commit 7004be998b.

Reason for revert: causing failures on many builders

Change-Id: I9216bd5409bb6814bac18a6a13ef5115db01b5fe
Reviewed-on: https://go-review.googlesource.com/c/go/+/229120
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-20 22:38:59 +00:00
David Finkel 7004be998b cmd/compile: adjust RISCV64 rewrite rules to use typed aux fields
Also add a typed version of mergeSym to rewrite.go to assist with a few
rules that used mergeSym in the untyped-form.

Remove a few extra int32 overflow checks that no longer make sense, as
adding two int8s or int16s should never overflow an int32.

Passes toolstash-check -all.

Change-Id: I72ddd2b0d9001faa87ad0ab54f500057164661b7
Reviewed-on: https://go-review.googlesource.com/c/go/+/228882
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-20 20:22:51 +00:00
Josh Bleecher Snyder 0239a5c478 cmd/compile: use fuse to implement shortcircuit loop
The rewrite loop in shortcircuit is identical to the one in fuse.
That's not surprising; shortcircuit is fuse-like.

Take advantage of that by merging the two loops.

Passes toolstash-check.

Change-Id: I642cb39a23d2ac8964ed577678f062fce721439c
Reviewed-on: https://go-review.googlesource.com/c/go/+/229003
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-20 19:36:50 +00:00
Josh Bleecher Snyder f8ff12d480 cmd/compile: use dereference boundedness hint in ssa.addr
Follow-up to (and similar to) CL 228885.
Triggers a handful of times in std+cmd.

Change-Id: Ie04057ca3974ef9eef669335e326a5ed4b7472cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/228999
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-20 17:27:11 +00:00
Josh Bleecher Snyder 4e550bdacd cmd/compile: simplify state.addr
OADDR nodes can't be bounded.
All calls to state.addr thus pass false.
Remove the argument.

Passes toolstash-check.

Change-Id: I9a3fcf37f63b2b5094e043d39ab3b857b5090e91
Reviewed-on: https://go-review.googlesource.com/c/go/+/228788
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-20 16:38:31 +00:00
Josh Bleecher Snyder e8518731be cmd/compile: use dereference boundedness hint during ssa conversion
This has a minor positive effect on generated code,
particularly code using type switches.

Change-Id: I7269769ab0d861ef6fc9e6d7809ffc3573c68340
Reviewed-on: https://go-review.googlesource.com/c/go/+/228885
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-20 16:36:22 +00:00
Josh Bleecher Snyder 5abf5f831e cmd/compile: clarify Node.NonNil and Node.Bounded
Node.NonNil and Node.Bounded were a bit muddled. This led to #38496.
This change clarifies and documents them.

It also corrects one misuse.
However, since ssa conversion doesn't make full use of the bounded hint,
this correction doesn't change any generated code.
The next change will fix that.

Passes toolstash-check.

Change-Id: I2bcd487a0a4aef5d7f6090e653974fce0dce3b8e
Reviewed-on: https://go-review.googlesource.com/c/go/+/228787
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-20 16:35:40 +00:00
Josh Bleecher Snyder 12d1c9b863 cmd/compile: delete gdata
All callers to gdata knew the kind of node they were working with,
so all calls to gdata have been replaced with more specific calls.

Some OADDR nodes were constructed solely for the purpose of
passing them to gdata for unwrapping. In those cases, we can now
cut to the chase.

Passes toolstash-check.

Change-Id: Iacc1abefd7f748cb269661a03768d3367319b0b0
Reviewed-on: https://go-review.googlesource.com/c/go/+/228888
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-20 15:37:49 +00:00
Josh Bleecher Snyder ed5233166f cmd/compile: simplify slicebytes
Use slicesym to implement. Remove len param.

Passes toolstash-check.

Change-Id: Ia6d4fb2a3b476eceeba60979b4dd82b634b43939
Reviewed-on: https://go-review.googlesource.com/c/go/+/228887
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-20 15:35:23 +00:00
Cuong Manh Le ea52c78a66 cmd/compile: remove useless nil check in symfmt
This is followup of CL 228861, which remove another un-necessary nil
check for s.Pkg.

Passes toolstash-check.

Change-Id: Ide750beddd2594199af21b56ec6af734dfa55b9c
Reviewed-on: https://go-review.googlesource.com/c/go/+/228862
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-20 05:15:38 +00:00
Cuong Manh Le 7711bad100 cmd/compile: remove nil check for p in isReflectPkg
CL 228859 refactored detecting reflect package logic in to isReflectPkg
function. The function has un-necessary nil check for p, so remove that
check.

Passes toolstash-check.

Change-Id: I2f3f1ac967fe8d176dda3f3b4698ded08602e2fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/228861
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-20 05:15:24 +00:00
Cuong Manh Le 62ccee49d6 cmd/compile: refactor detecting package reflect logic
Passes toolstash-check.

Change-Id: Ie4b1f61528bb183dc66bb6955851a47b2641549c
Reviewed-on: https://go-review.googlesource.com/c/go/+/228859
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-20 02:39:16 +00:00
Cuong Manh Le 885099d155 cmd/compile: rewrite integer range rules to use typed aux fields
Passes toolstash-check.

Change-Id: I2752e4df211294112d502a59c3b9988e00d25aae
Reviewed-on: https://go-review.googlesource.com/c/go/+/228857
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-19 10:52:23 +00:00
Alberto Donizetti bbaae9c43d cmd/compile: switch to typed aux for 386 lowering rules
Convert all the 386 lowering rules to the typed aux form.

Passes

  GOARCH=386 gotip build -toolexec 'toolstash -cmp' -a std

Change-Id: I15256f20bc4442391755e6fffb8206dcaab94830
Reviewed-on: https://go-review.googlesource.com/c/go/+/228818
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-19 07:27:45 +00:00
Cherry Zhang a32262d462 cmd/compile: when marking REFLECTMETHOD, check for reflect package itself
reflect.Type.Method (and MethodByName) can be used to obtain a
reference of a method by reflection. The linker needs to know
if reflect.Type.Method is called, and retain all exported methods
accordingly. This is handled by the compiler, which marks the
caller of reflect.Type.Method with REFLECTMETHOD attribute. The
current code failed to handle the reflect package itself, so the
method wrapper reflect.Type.Method is not marked. This CL fixes
it.

Fixes #38515.

Change-Id: I12904d23eda664cf1794bc3676152f3218fb762b
Reviewed-on: https://go-review.googlesource.com/c/go/+/228880
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-19 03:12:32 +00:00
Daniel Martí f5291cf03d cmd/compile: use exported field names in rulegen
The types used while generating code, such as Rule and File, have been
exported for a while. This is harmless for a main package, and lets us
easily differentiate types from variables and functions, as well as use
names like "If" since "if" is a keyword.

However, the fields remained unexported. This was a bit inconsistent,
and also meant that we couldn't use some intuitive names like If.else.
Export them.

Besides the capitalization, the only change is that the If type now has
the fields Then and Else, instead of stmt and alt.

Change-Id: I426ff140c6ca186fec394f17b29165861da5fd98
Reviewed-on: https://go-review.googlesource.com/c/go/+/228821
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-18 20:01:46 +00:00
Josh Bleecher Snyder 80e5c3b8b5 cmd/compile: remove superfluous SetBounded call
The call does nothing when applied to an OLSH node.
It would be unnecessary anyway, since we're shifting by a small constant.

Passes toolstash-check.

Change-Id: If858711f1704f44637fa0f6a4c66cbaad6db24b8
Reviewed-on: https://go-review.googlesource.com/c/go/+/228699
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-04-17 15:33:31 +00:00
Michael Munday b1cae8cd1d cmd/compile: make some s390x rules use strongly typed aux values
This first pass makes the rules using the condition code mask
(CCMask) and rotate parameters (RotateParams) aux values strongly
typed. This required adding strongly typed aux handling to the
block rulegen.

More CLs like this to follow, but this is probably the most
complex.

Passes toolstash-check -all.

Change-Id: Ie513b07d527f0c1b398d7748331442dcb5f7b17d
Reviewed-on: https://go-review.googlesource.com/c/go/+/228518
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-17 14:54:05 +00:00
Matthew Dempsky 843453d09e cmd/compile: fix misassumption about n.Left.Bounded()
n.Bounded() is overloaded for multiple meanings based on n.Op. We
can't safely use n.Left.Bounded() without checking n.Left.Op.

Change-Id: I71fe4faa24798dfe3a5705fa3419a35ef93b0ce2
Reviewed-on: https://go-review.googlesource.com/c/go/+/228677
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2020-04-17 01:07:31 +00:00
Matthew Dempsky 415da71c5d cmd/compile: remove totype0 type-constructor helpers
These were originally introduced for the binary export format, which
required forward references to arbitrary types and later filling them
in. They're no longer needed since we switched to the indexed export
format, which only requires forward references to declared types.

Passes toolstash-check.

Change-Id: I696dc9029ec7652d01ff49fb98e658a9ed510979
Reviewed-on: https://go-review.googlesource.com/c/go/+/228579
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-16 22:06:45 +00:00
Josh Bleecher Snyder ab3bd2c15f cmd/compile: make AlgKind a stringer
Change-Id: I4a4b866d9233b8369e5ca913a9dd576b323b8f3e
Reviewed-on: https://go-review.googlesource.com/c/go/+/228421
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-04-16 03:19:50 +00:00
David Chase e4e192484b cmd/compile: split up the addressing mode on OpAMD64CMP*loadidx* always
Benchmarking suggests that the combo instruction is notably slower,
at least in the places where we measure.

Updates #37955

Change-Id: I829f1975dd6edf38163128ba51d84604055512f4
Reviewed-on: https://go-review.googlesource.com/c/go/+/228157
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-15 18:09:14 +00:00
Michael Munday 48403b268b cmd/compile: error if register is reused when setting edge state
When setting the edge state in register allocation we should only
be setting each register once. It is not possible for a register
to hold multiple values at once.

This CL converts the runtime error seen in #38195 into an internal
compiler error (ICE). It is better for the compiler to fail than
generate an incorrect program.

The bug reported in #38195 is now exposed as:

./parserc.go:459:11: internal compiler error: 'yaml_parser_parse_node': R5 is already set (v1074/v1241)

[stack trace]

Updates #38195.

Change-Id: Id95842fd850b95494cbd472b6fd5a55513ecacec
Reviewed-on: https://go-review.googlesource.com/c/go/+/228060
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-14 19:04:38 +00:00
Michael Munday 382fe3e249 cmd/compile: fix deallocation of live value copies in regalloc
When deallocating the input register to a phi so that the phi
itself could be allocated to that register the code was also
deallocating all copies of that phi input value. Those copies
of the value could still be live and if they were the register
allocator could reuse them incorrectly to hold speculative
copies of other phi inputs. This causes strange bugs.

No test because this is a very obscure scenario that is hard
to replicate but CL 228060 adds an assertion to the compiler
that does trigger when running the std tests on linux/s390x
without this CL applied. Hopefully that assertion will prevent
future regressions.

Fixes #38195.

Change-Id: Id975dadedd731c7bb21933b9ea6b17daaa5c9e1d
Reviewed-on: https://go-review.googlesource.com/c/go/+/228061
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-14 19:04:32 +00:00
Michael Munday 334d410ae3 cmd/compile: fix incorrect block for s390x Select1 op
When inserting Select0 and Select1 ops we need to ensure that they
live in the same block as their argument. This is because they need
to be scheduled immediately after their argument for register and
flag allocation to work correctly.

Fixes #38356.

Change-Id: Iba384dbe87010f1c7c4ce909f08011e5f1de7fd5
Reviewed-on: https://go-review.googlesource.com/c/go/+/227879
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-14 19:01:47 +00:00
Josh Bleecher Snyder f5439d4c68 cmd/compile: make type switch case positions consistent
CL 228106 moved the position at which we
checked whether a type switch variable had a particular type
from the type switch to the case statement, but only for
single, concrete types. This is a better position,
so this change changes the rest.

Change-Id: I601d4a5c4a0d9400e7804b9f1e729af948349a8f
Reviewed-on: https://go-review.googlesource.com/c/go/+/228220
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-04-14 17:44:16 +00:00
Josh Bleecher Snyder 02ab2c040e cmd/compile: make ifaceData accept a position
This lets us provide a better position in its use in swt.go.

Change-Id: I7c0da6bd0adea81acfc9a591e6a01b241a5e0942
Reviewed-on: https://go-review.googlesource.com/c/go/+/228219
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
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2020-04-14 17:43:56 +00:00
Josh Bleecher Snyder 2db4cc38a0 cmd/compile: improve generated code for concrete cases in type switches
Consider

switch x:= x.(type) {
case int:
  // int stmts
case error:
  // error stmts
}

Prior to this change, we lowered this roughly as:

if x, ok := x.(int); ok {
  // int stmts
} else if x, ok := x.(error); ok {
  // error stmts
}

x, ok := x.(error) is implemented with a call to runtime.assertE2I2 or runtime.assertI2I2.

x, ok := x.(int) generates inline code that checks whether x has type int,
and populates x and ok as appropriate. We then immediately branch again on ok.
The shortcircuit pass in the SSA backend is designed to recognize situations
like this, in which we are immediately branching on a bool value
that we just calculated with a branch.

However, the shortcircuit pass has limitations when the intermediate state has phis.
In this case, the phi value is x (the int).
CL 222923 improved the situation, but many cases are still unhandled.
I have further improvements in progress, which is how I found this particular problem,
but they are expensive, and may or may not see the light of day.

In the common case of a lone concrete type in a type switch case,
it is easier and cheaper to simply lower a different way, roughly:

if _, ok := x.(int); ok {
  x := x.(int)
  // int stmts
}

Instead of using a type assertion, though, we extract the value of x
from the interface directly.

This removes the need to track x (the int) across the branch on ok,
which removes the phi, which lets the shortcircuit pass do its job.

Benchmarks for encoding/binary show improvements, as well as some
wild swings on the super fast benchmarks (alignment effects?):

name                      old time/op    new time/op    delta
ReadSlice1000Int32s-8       5.25µs ± 2%    4.87µs ± 3%   -7.11%  (p=0.000 n=44+49)
ReadStruct-8                 451ns ± 2%     417ns ± 2%   -7.39%  (p=0.000 n=45+46)
WriteStruct-8                412ns ± 2%     405ns ± 3%   -1.58%  (p=0.000 n=46+48)
ReadInts-8                   296ns ± 8%     275ns ± 3%   -7.23%  (p=0.000 n=48+50)
WriteInts-8                  324ns ± 1%     318ns ± 2%   -1.67%  (p=0.000 n=44+49)
WriteSlice1000Int32s-8      5.21µs ± 2%    4.92µs ± 1%   -5.67%  (p=0.000 n=46+44)
PutUint16-8                 0.58ns ± 2%    0.59ns ± 2%   +0.63%  (p=0.000 n=49+49)
PutUint32-8                 0.87ns ± 1%    0.58ns ± 1%  -33.10%  (p=0.000 n=46+44)
PutUint64-8                 0.66ns ± 2%    0.87ns ± 2%  +33.07%  (p=0.000 n=47+48)
LittleEndianPutUint16-8     0.86ns ± 2%    0.87ns ± 2%   +0.55%  (p=0.003 n=47+50)
LittleEndianPutUint32-8     0.87ns ± 1%    0.87ns ± 1%     ~     (p=0.547 n=45+47)
LittleEndianPutUint64-8     0.87ns ± 2%    0.87ns ± 1%     ~     (p=0.451 n=46+47)
ReadFloats-8                79.8ns ± 5%    75.9ns ± 2%   -4.83%  (p=0.000 n=50+47)
WriteFloats-8               89.3ns ± 1%    88.9ns ± 1%   -0.48%  (p=0.000 n=46+44)
ReadSlice1000Float32s-8     5.51µs ± 1%    4.87µs ± 2%  -11.74%  (p=0.000 n=47+46)
WriteSlice1000Float32s-8    5.51µs ± 1%    4.93µs ± 1%  -10.60%  (p=0.000 n=48+47)
PutUvarint32-8              25.9ns ± 2%    24.0ns ± 2%   -7.02%  (p=0.000 n=48+50)
PutUvarint64-8              75.1ns ± 1%    61.5ns ± 2%  -18.12%  (p=0.000 n=45+47)
[Geo mean]                  57.3ns         54.3ns        -5.33%

Despite the rarity of type switches, this generates noticeably smaller binaries.

file      before    after     Δ       %
addr2line 4413296   4409200   -4096   -0.093%
api       5982648   5962168   -20480  -0.342%
cgo       4854168   4833688   -20480  -0.422%
compile   19694784  19682560  -12224  -0.062%
cover     5278008   5265720   -12288  -0.233%
doc       4694824   4682536   -12288  -0.262%
fix       3411336   3394952   -16384  -0.480%
link      6721496   6717400   -4096   -0.061%
nm        4371152   4358864   -12288  -0.281%
objdump   4760960   4752768   -8192   -0.172%
pprof     14810820  14790340  -20480  -0.138%
trace     11681076  11668788  -12288  -0.105%
vet       8285464   8244504   -40960  -0.494%
total     115824120 115627576 -196544 -0.170%

Compiler performance is marginally improved (note that go/types has many type switches):

name        old alloc/op      new alloc/op      delta
Template         35.0MB ± 0%       35.0MB ± 0%  +0.09%  (p=0.008 n=5+5)
Unicode          28.5MB ± 0%       28.5MB ± 0%    ~     (p=0.548 n=5+5)
GoTypes           114MB ± 0%        114MB ± 0%  -0.76%  (p=0.008 n=5+5)
Compiler          541MB ± 0%        541MB ± 0%  -0.03%  (p=0.008 n=5+5)
SSA              1.17GB ± 0%       1.17GB ± 0%    ~     (p=0.841 n=5+5)
Flate            21.9MB ± 0%       21.9MB ± 0%    ~     (p=0.421 n=5+5)
GoParser         26.9MB ± 0%       26.9MB ± 0%    ~     (p=0.222 n=5+5)
Reflect          74.6MB ± 0%       74.6MB ± 0%    ~     (p=1.000 n=5+5)
Tar              32.9MB ± 0%       32.8MB ± 0%    ~     (p=0.056 n=5+5)
XML              42.4MB ± 0%       42.1MB ± 0%  -0.77%  (p=0.008 n=5+5)
[Geo mean]       73.2MB            73.1MB       -0.15%

name        old allocs/op     new allocs/op     delta
Template           377k ± 0%         377k ± 0%  +0.06%  (p=0.008 n=5+5)
Unicode            354k ± 0%         354k ± 0%    ~     (p=0.095 n=5+5)
GoTypes           1.31M ± 0%        1.30M ± 0%  -0.73%  (p=0.008 n=5+5)
Compiler          5.44M ± 0%        5.44M ± 0%  -0.04%  (p=0.008 n=5+5)
SSA               11.7M ± 0%        11.7M ± 0%    ~     (p=1.000 n=5+5)
Flate              239k ± 0%         239k ± 0%    ~     (p=1.000 n=5+5)
GoParser           302k ± 0%         302k ± 0%  -0.04%  (p=0.008 n=5+5)
Reflect            977k ± 0%         977k ± 0%    ~     (p=0.690 n=5+5)
Tar                346k ± 0%         346k ± 0%    ~     (p=0.889 n=5+5)
XML                431k ± 0%         430k ± 0%  -0.25%  (p=0.008 n=5+5)
[Geo mean]         806k              806k       -0.10%

For packages with many type switches, this considerably shrinks function text size.
Some examples:

file                                                           before   after    Δ       %
encoding/binary.s                                              30726    29504    -1222   -3.977%
go/printer.s                                                   77597    76005    -1592   -2.052%
cmd/vendor/golang.org/x/tools/go/ast/astutil.s                 65704    63318    -2386   -3.631%
cmd/vendor/golang.org/x/tools/go/analysis/passes/unreachable.s 8047     7714     -333    -4.138%

Text size regressions are rare.

Change-Id: Ic10982bbb04876250eaa5bfee97990141ae5fc28
Reviewed-on: https://go-review.googlesource.com/c/go/+/228106
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
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Reviewed-by: Keith Randall <khr@golang.org>
2020-04-14 17:34:31 +00:00
Cuong Manh Le 54cbb6b0c2 cmd/compile: mark static arrays when initialize map literal as noalg
Same thing as CL 228222 does with static slice.

file      before    after     Δ       %
go        15228932  15228756  -176    -0.001%
addr2line 4429680   4429616   -64     -0.001%
api       5999032   5994904   -4128   -0.069%
asm       5087928   5087864   -64     -0.001%
compile   19727984  19723792  -4192   -0.021%
cover     5290296   5290184   -112    -0.002%
dist      3711816   3711784   -32     -0.001%
doc       4711208   4711176   -32     -0.001%
nm        4379344   4379264   -80     -0.002%
objdump   4773248   4773168   -80     -0.002%
pprof     14856148  14855764  -384    -0.003%
trace     11718212  11718020  -192    -0.002%
vet       8305944   8301768   -4176   -0.050%
total     131377612 131363900 -13712  -0.010%

Change-Id: I5ec00580b1509486c13aca43ad8f5cc7c450b62e
Reviewed-on: https://go-review.googlesource.com/c/go/+/227812
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2020-04-14 16:39:49 +00:00
Josh Bleecher Snyder 2222e0601a cmd/compile: mark static slice backing arrays as noalg
file      before    after     Δ       %       
addr2line 4413296   4404160   -9136   -0.207% 
api       5982648   5978232   -4416   -0.074% 
asm       5075640   5057656   -17984  -0.354% 
buildid   2886200   2881304   -4896   -0.170% 
cgo       4854168   4844936   -9232   -0.190% 
compile   19694784  19680752  -14032  -0.071% 
cover     5278008   5269256   -8752   -0.166% 
dist      3699528   3690984   -8544   -0.231% 
doc       4694824   4690408   -4416   -0.094% 
fix       3411336   3411048   -288    -0.008% 
link      6721496   6703320   -18176  -0.270% 
nm        4371152   4357904   -13248  -0.303% 
objdump   4760960   4747680   -13280  -0.279% 
pack      2340824   2336520   -4304   -0.184% 
pprof     14810820  14801188  -9632   -0.065% 
test2json 2861896   2857528   -4368   -0.153% 
trace     11681076  11676228  -4848   -0.042% 
vet       8285464   8276184   -9280   -0.112% 
total     115824120 115665288 -158832 -0.137% 

Change-Id: I66e1985c3a81cd9b2aa72cb4b4a8aa1781e473b9
Reviewed-on: https://go-review.googlesource.com/c/go/+/228222
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2020-04-14 16:09:47 +00:00
Cuong Manh Le 34e38ac99f cmd/compile: remove "special return in disguise" case
ascompatee does not generate 'x = x' during return, so we don't have to
check for samelist and disguising special return anymore.

While at it, also remove samelist, as this is the only place it's used.

Passes toolstash-check.

Change-Id: I41c7b077d562aadb5916a61e2ab6229bae3cdef4
Reviewed-on: https://go-review.googlesource.com/c/go/+/227807
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2020-04-14 07:12:17 +00:00
Cherry Zhang 1b15c7f102 cmd/compile: debug rewrite
If -d=ssa/PASS/debug=N is specified (N >= 2) for a rewrite pass
(e.g. lower), when a Value (or Block) is rewritten, print the
Value (or Block) before and after.

For #31915.
Updates #19013.

Change-Id: I80eadd44302ae736bc7daed0ef68529ab7a16776
Reviewed-on: https://go-review.googlesource.com/c/go/+/176718
Run-TryBot: Cherry Zhang <cherryyz@google.com>
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2020-04-13 21:56:15 +00:00
Joel Sing d3d21d0a42 cmd/compile: update TestIntendedInlining for riscv64
Mark nextFreeFast as not inline, as it is too expensive to inline on riscv64.
Also remove riscv64 from non-atomic inline architectures, as we now have
atomic intrisics.

Updates #22239

Change-Id: I6e0e72c1192070e39f065bee486f48df4cc74b35
Reviewed-on: https://go-review.googlesource.com/c/go/+/227808
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2020-04-13 17:29:23 +00:00
Keith Randall 1e820a3432 cmd/compile: ensure ... rules have compatible aux and auxint types
Otherwise, just copying the aux and auxint fields doesn't make much sense.
(Although there's no bug - it just means it isn't typechecked correctly.)

Change-Id: I4e21ac67f0c7bfd04ed5af1713cd24bca08af092
Reviewed-on: https://go-review.googlesource.com/c/go/+/227962
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2020-04-13 15:41:40 +00:00
Keith Randall dc9879e8fd cmd/compile: convert more AMD64.rules lines to typed aux mode
Change-Id: Idded860128b1a23680520d8c2b9f6d8620dcfcc7
Reviewed-on: https://go-review.googlesource.com/c/go/+/228077
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2020-04-13 15:41:13 +00:00
Joel Sing c39439c53f cmd/compile: run TestLogOpt for riscv64 on amd64
Run TestLogOpt for riscv64 on amd64, as is done for other architectures.
This would have caught the test failure on riscv64 introduced in
47ade08141.

Change-Id: If29dea2ef383b087154d046728f6d1c96811f5a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/227806
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2020-04-13 04:05:32 +00:00
Keith Randall 2f84caebe3 cmd/compile: rewrite some AMD64 rules to use typed aux fields
Surprisingly many rules needed no modification.

Use wrapper functions for aux like we did for auxint.
Simplifies things a bit.

Change-Id: I2e852e77f1585dcb306a976ab9335f1ac5b4a770
Reviewed-on: https://go-review.googlesource.com/c/go/+/227961
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2020-04-12 23:46:56 +00:00
Keith Randall 7580937524 cmd/compile: move more generic rewrites to the typed version
Change-Id: I22d0644710d12c7efc509fd2a15789e2e073e6a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/227869
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2020-04-12 19:41:35 +00:00
Joel Sing fb16f4b82e cmd/compile: log large copies on riscv64
Log large copies in the riscv64 compiler.

This was missed in 47ade08141, resulting in
the new test added to cmd/compile/internal/logopt failing on riscv64.

Change-Id: I6f763e86f42834148e911d16928f9fbabcfa4290
Reviewed-on: https://go-review.googlesource.com/c/go/+/227804
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2020-04-12 17:51:29 +00:00
Joel Sing 1eb66be1b9 cmd/compile: enable Sqrt as a compiler intrinsic on riscv64
Change-Id: I829a02ced9aa73b45079e67194186116b39504b0
Reviewed-on: https://go-review.googlesource.com/c/go/+/227805
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2020-04-12 16:51:25 +00:00