Commit graph

138 commits

Author SHA1 Message Date
Zhongwei Yao
74a9bad638 cmd/compile: enable const division for arm64
performance:
benchmark                   old ns/op     new ns/op     delta
BenchmarkDivconstI64-8      8.28          2.70          -67.39%
BenchmarkDivconstU64-8      8.28          4.69          -43.36%
BenchmarkDivconstI32-8      8.28          6.39          -22.83%
BenchmarkDivconstU32-8      8.28          4.43          -46.50%
BenchmarkDivconstI16-8      5.17          5.17          +0.00%
BenchmarkDivconstU16-8      5.33          5.34          +0.19%
BenchmarkDivconstI8-8       3.50          3.50          +0.00%
BenchmarkDivconstU8-8       3.51          3.50          -0.28%

Fixes #15382

Change-Id: Ibce7b28f0586d593b33c4d4ecc5d5e7e7c905d13
Reviewed-on: https://go-review.googlesource.com/22292
Reviewed-by: Michael Munday <munday@ca.ibm.com>
Reviewed-by: David Chase <drchase@google.com>
2016-04-27 17:47:49 +00:00
Dave Cheney
8f2e780e8a cmd/compile/internal: unexport gc.Oconv
Updates #15462

Semi automatic change with gofmt -r and hand fixups for callers outside
internal/gc.

All the uses of gc.Oconv outside cmd/compile/internal/gc were for the
Oconv(op, 0) form, which is already handled the Op.String method.

Replace the use of gc.Oconv(op, 0) with op itself, which will call
Op.String via the %v or %s verb. Unexport Oconv.

Change-Id: I84da2a2e4381b35f52efce427b2d6a3bccdf2526
Reviewed-on: https://go-review.googlesource.com/22496
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-27 06:18:46 +00:00
Matthew Dempsky
e48a2958d1 cmd/compile: treat empty and absent struct field tags as identical
Fixes #15439.

Change-Id: I5a32384c46e20f8db6968e5a9e854c45ab262fe4
Reviewed-on: https://go-review.googlesource.com/22429
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-25 21:28:45 +00:00
Josh Bleecher Snyder
f12bd8a5a8 cmd/compile: encapsulate OSLICE* representation
As a nice side-effect, this allows us to
unify several code paths.

The terminology (low, high, max, simple slice expr,
full slice expr) is taken from the spec and
the examples in the spec.

This is a trial run. The plan, probably for Go 1.8,
is to change slice expressions to use Node.List
instead of OKEY, and to do some similar
tree structure changes for other ops.

Passes toolstash -cmp. No performance change.
all.bash passes with GO_GCFLAGS=-newexport.

Updates #15350

Change-Id: Ic1efdc36e79cdb95ae1636e9817a3ac8f83ab1ac
Reviewed-on: https://go-review.googlesource.com/22425
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-04-25 18:39:33 +00:00
Josh Bleecher Snyder
1da62afeef cmd/compile: replace len(Nodes.Slice()) with Nodes.Len()
Generated with eg:

func before(n gc.Nodes) int { return len(n.Slice()) }
func after(n gc.Nodes) int  { return n.Len() }

Change-Id: Ifdf01915e60069166afe96aa7b1d08720bf62fc5
Reviewed-on: https://go-review.googlesource.com/22420
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-25 02:13:22 +00:00
Josh Bleecher Snyder
b6b144bf97 cmd/compile: don't generate algs for ... args
Note that this is only safe because
the compiler generates multiple distinct
gc.Types. If we switch to having canonical
gc.Types, then this will need to be updated
to handle the case in which the user uses both
map[[n]T]S and also calls a function f(...T) with n arguments.
In that case, the runtime needs algs for [n]T, but this could
mark the sole [n]T type as Noalg. This is a general
problem with having a single bool to represent
whether alg generation is needed for a type.

Cuts 17k off cmd/go and 13k off golang.org/x/tools/cmd/godoc,
approx 0.14% and 0.07% respectively.

For #6853 and #9930

Change-Id: Iccb6b9fd88ade5497d7090528a903816d340bf0a
Reviewed-on: https://go-review.googlesource.com/19770
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-24 20:51:04 +00:00
Keith Randall
934c359964 cmd/compile: reorder how slicelit initializes a slice
func f(x, y, z *int) {
    a := []*int{x,y,z}
    ...
  }

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

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

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

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

Makes go binaries ~1% smaller.

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

Fixes #14263
Update #6853

Change-Id: I9074a2788ec9e561a75f3b71c119b69f304d6ba2
Reviewed-on: https://go-review.googlesource.com/22395
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-24 18:15:41 +00:00
Keith Randall
3c1a4c1902 cmd/compile: don't nilcheck newobject and return values from mapaccess{1,2}
They are guaranteed to be non-nil, no point in inserting
nil checks for them.

Fixes #15390

Change-Id: I3b9a0f2319affc2139dcc446d0a56c6785ae5a86
Reviewed-on: https://go-review.googlesource.com/22291
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-22 16:18:42 +00:00
Matthew Dempsky
40f1d0ca9f cmd/compile: split TSLICE into separate Type kind
Instead of using TARRAY for both arrays and slices, create a new
TSLICE kind to handle slices.

Also, get rid of the "DDDArray" distinction. While kinda ugly, it
seems likely we'll need to defer evaluating the constant bounds
expressions for golang.org/issue/13890.

Passes toolstash/buildall.

Change-Id: I8e45d4900e7df3a04cce59428ec8b38035d3cc3a
Reviewed-on: https://go-review.googlesource.com/22329
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 21:03:22 +00:00
Keith Randall
60fd32a47f cmd/compile: change the way we handle large map values
mapaccess{1,2} returns a pointer to the value.  When the key
is not in the map, it returns a pointer to zeroed memory.
Currently, for large map values we have a complicated scheme which
dynamically allocates zeroed memory for this purpose.  It is ugly
code and requires an atomic.Load in a bunch of places we'd rather
not have it.

Switch to a scheme where callsites of mapaccess{1,2} which expect
large return values pass in a pointer to zeroed memory that
mapaccess can return if the key is not found.  This avoids the
atomic.Load on all map accesses with a few extra instructions only
for the large value acccesses, plus a bit of bss space.

There was a time (1.4 & 1.5?) where we did something like this but
all the tricks to make the right size zero value were done by the
linker.  That scheme broke in the presence of dyamic linking.
The scheme in this CL works even when dynamic linking.

Fixes #12337

Change-Id: Ic2d0319944af33bbb59785938d9ab80958d1b4b1
Reviewed-on: https://go-review.googlesource.com/22221
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2016-04-20 21:15:31 +00:00
Keith Randall
bfe0cbdc50 cmd/compile,runtime: pass elem type to {make,grow}slice
No point in passing the slice type to these functions.
All they need is the element type.  One less indirection,
maybe a few less []T type descriptors in the binary.

Change-Id: Ib0b83b5f14ca21d995ecc199ce8ac00c4eb375e6
Reviewed-on: https://go-review.googlesource.com/22275
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-20 00:31:16 +00:00
Josh Bleecher Snyder
3c6e60c0e4 cmd/compile: fix isStaticCompositeLiteral
Previously, isStaticCompositeLiteral would
return the wrong value for literals like:

[1]struct{ b []byte }{b: []byte{1}}

Note that the outermost component is an array,
but once we recurse into isStaticCompositeLiteral,
we never check again that arrays are actually arrays.

Instead of adding more logic to the guts of
isStaticCompositeLiteral, allow it to accept
any Node and return the correct answer.

Change-Id: I6af7814a9037bbc7043da9a96137fbee067bbe0e
Reviewed-on: https://go-review.googlesource.com/22247
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-19 20:55:41 +00:00
Keith Randall
b024ed0d94 cmd/compile: eliminate copy for static literals
*p = [5]byte{1,2,3,4,5}

First we allocate a global containing the RHS.  Then we copy
that global to a local stack variable, and then copy that local
stack variable to *p.  The intermediate copy is unnecessary.

Note that this only works if the RHS is completely constant.
If the code was:
*p = [5]byte{1,2,x,4,5}
this optimization doesn't apply as we have to construct the
RHS on the stack before copying it to *p.

Fixes #12841

Change-Id: I7cd0404ecc7a2d1750cbd8fe1222dba0fa44611f
Reviewed-on: https://go-review.googlesource.com/22192
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-18 18:51:10 +00:00
Matthew Dempsky
980ab12ade cmd/compile/internal/gc: change flags to bool where possible
Some of the Debug[x] flags are actually boolean too, but not all, so
they need to be handled separately.

While here, change some obj.Flagstr and obj.Flagint64 calls to
directly use flag.StringVar and flag.Int64Var instead.

Change-Id: Iccedf6fed4328240ee2257f57fe6d66688f237c4
Reviewed-on: https://go-review.googlesource.com/22052
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2016-04-14 02:10:35 +00:00
Michael Munday
613ba6cda8 cmd/compile/internal/gc: add s390x support
Allows instructions with a From3 field to be used in regopt so
long as From3 represents a constant. This is needed because the
storage-to-storage instructions on s390x place the length of the
data into From3.

Change-Id: I12cd32d4f997baf2fe97937bb7d45bbf716dfcb5
Reviewed-on: https://go-review.googlesource.com/20875
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
2016-04-12 18:04:02 +00:00
Matthew Dempsky
c6e11fe037 cmd: add new common architecture representation
Information about CPU architectures (e.g., name, family, byte
ordering, pointer and register size) is currently redundantly
scattered around the source tree. Instead consolidate the basic
information into a single new package cmd/internal/sys.

Also, introduce new sys.I386, sys.AMD64, etc. names for the constants
'8', '6', etc. and replace most uses of the latter. The notable
exceptions are a couple of error messages that still refer to the old
char-based toolchain names and function reltype in cmd/link.

Passes toolstash/buildall.

Change-Id: I8a6f0cbd49577ec1672a98addebc45f767e36461
Reviewed-on: https://go-review.googlesource.com/21623
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-07 01:23:25 +00:00
Josh Bleecher Snyder
f38f43d029 cmd/compile: shrink gc.Type in half
Many of Type's fields are etype-specific.
This CL organizes them into their own auxiliary types,
duplicating a few fields as necessary,
and adds an Extra field to hold them.
It also sorts the remaining fields for better struct packing.
It also improves documentation for most fields.

This reduces the size of Type at the cost of some extra allocations.
There's no CPU impact; memory impact below.
It also makes the natural structure of Type clearer.

Passes toolstash -cmp on all architectures.

Ideas for future work in this vein:

(1) Width and Align probably only need to be
stored for Struct and Array types.
The refactoring to accomplish this would hopefully
also eliminate TFUNCARGS and TCHANARGS entirely.

(2) Maplineno is sparsely used and could probably better be
stored in a separate map[*Type]int32, with mapqueue updated
to store both a Node and a line number.

(3) The Printed field may be removable once the old (non-binary)
importer/exported has been removed.

(4) StructType's fields field could be changed from *[]*Field to []*Field,
which would remove a common allocation.

(5) I believe that Type.Nod can be moved to ForwardType. Separate CL.

name       old alloc/op     new alloc/op     delta
Template       57.9MB ± 0%      55.9MB ± 0%  -3.43%        (p=0.000 n=50+50)
Unicode        38.3MB ± 0%      37.8MB ± 0%  -1.39%        (p=0.000 n=50+50)
GoTypes         185MB ± 0%       180MB ± 0%  -2.56%        (p=0.000 n=50+50)
Compiler        824MB ± 0%       806MB ± 0%  -2.19%        (p=0.000 n=50+50)

name       old allocs/op    new allocs/op    delta
Template         486k ± 0%        497k ± 0%  +2.25%        (p=0.000 n=50+50)
Unicode          377k ± 0%        379k ± 0%  +0.55%        (p=0.000 n=50+50)
GoTypes         1.39M ± 0%       1.42M ± 0%  +1.63%        (p=0.000 n=50+50)
Compiler        5.52M ± 0%       5.57M ± 0%  +0.84%        (p=0.000 n=47+50)

Change-Id: I828488eeb74902b013d5ae4cf844de0b6c0dfc87
Reviewed-on: https://go-review.googlesource.com/21611
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-06 19:10:10 +00:00
Josh Bleecher Snyder
fda831ed3f cmd/compile: encapsulate reads of gc.Type.Funarg
Changes generated with eg and then manually
checked and in some cases simplified.

Passes toolstash -cmp.

Change-Id: I2119f37f003368ce1884d2863b406d6ffbfe38c7
Reviewed-on: https://go-review.googlesource.com/21563
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-04-06 02:49:18 +00:00
Eric Engestrom
7a8caf7d43 all: fix spelling mistakes
Signed-off-by: Eric Engestrom <eric@engestrom.ch>

Change-Id: I91873aaebf79bdf1c00d38aacc1a1fb8d79656a7
Reviewed-on: https://go-review.googlesource.com/21433
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-03 17:03:15 +00:00
Matthew Dempsky
75a22d0d10 cmd/compile: eliminate dead code in walkappend
The IsStruct case is meant to handle cases like append(f()) where f's
result parameters are something like ([]int, int, int). However, at
this point in the compiler we've already rewritten append(f()) into
"tmp1, tmp2, tmp3 := f(); append(tmp1, tmp2, tmp3)".

As further evidence, the t.Elem() is not a valid method call for a
struct type anyway, which would trigger the Fatalf call in Type.Elem
if this code was ever hit.

Change-Id: Ia066f93df66ee3fadc9a9a0f687be7b5263af163
Reviewed-on: https://go-review.googlesource.com/21427
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-02 00:06:30 +00:00
Josh Bleecher Snyder
5cab01698a cmd/compile: rename Node.Int to Node.Int64
gorename -from '"cmd/compile/internal/gc".Node.Int' -to 'Int64'

Change-Id: I2fe3bf9a26ae6b0600d990d0c981e4b8b53020a4
Reviewed-on: https://go-review.googlesource.com/21426
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-01 22:00:47 +00:00
Matthew Dempsky
00e5a68c3e cmd/compile: more Isfoo Type cleanups
Replace isideal(t) with t.IsUntyped().
Replace Istype(t, k) with t.IsKind(k).
Replace isnilinter(t) with t.IsEmptyInterface().

Also replace a lot of t.IsKind(TFOO) with t.IsFoo().

Replacements prepared mechanically with gofmt -w -r.

Passes toolstash -cmp.

Change-Id: Iba48058f3cc863e15af14277b5ff5e729e67e043
Reviewed-on: https://go-review.googlesource.com/21424
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
2016-04-01 21:08:39 +00:00
Josh Bleecher Snyder
e504055e78 cmd/compile: use Node.Int more
Generated by eg.

Passes toolstash -cmp.

Change-Id: I7516c211ca9aacf824f74894671dc62d31763b01
Reviewed-on: https://go-review.googlesource.com/21422
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-01 20:03:39 +00:00
Josh Bleecher Snyder
3a0783c504 cmd/compile: use NumElem instead of Type.Bound
This eliminates all direct reads of Type.Bound
outside type.go.

Change-Id: I0a9a72539f8f4c0de7f5e05e1821936bf7db5eb7
Reviewed-on: https://go-review.googlesource.com/21421
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-01 20:03:19 +00:00
Matthew Dempsky
077902d1a6 cmd/compile: cleanup algtype code
Add AlgKind enum type to represent AFOO values.

Add IsComparable, IsRegularMemory, IncomparableField helper methods to
codify common higher-level idioms.

Passes toolstash -cmp.

Change-Id: I54c544953997a8ccc72396b3058897edcbbea392
Reviewed-on: https://go-review.googlesource.com/21420
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-01 19:23:53 +00:00
Ian Lance Taylor
92bb694a49 cmd/compile: s.f aliases itself
The change in 20907 fixed varexpr but broke aliased.  After that change,
a reference to a field in a struct would not be seen as aliasing itself.
Before that change, it would, but only because all fields in a struct
aliased everything.

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

Fixes #15042.

Change-Id: I5c95c0dd7b0699e53022fce9bae2e8f50d6d1d04
Reviewed-on: https://go-review.googlesource.com/21390
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-04-01 00:47:56 +00:00
Matthew Dempsky
e76fc1b921 cmd/compile: use t.IsFoo() instead of Isfoo[t.Etype]
This allows us to get rid of Isptr and Issigned. Still some code to
clean up for Isint, Isfloat, and Iscomplex.

CL produced mechanically using gofmt -w -r.

Passes toolstash -cmp.

Change-Id: If4f807bb7f2b357288d2547be2380eb511875786
Reviewed-on: https://go-review.googlesource.com/21339
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-03-30 22:48:34 +00:00
Matthew Dempsky
3efefd9395 cmd/compile: use t.IsFoo() instead of t.Etype == TFOO
CL produced mechanically using gofmt -w -r.

Passes toolstash -cmp.

Change-Id: Ib2e8710ebd844e2149125b41c335b71a02fcab53
Reviewed-on: https://go-review.googlesource.com/21338
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-30 22:31:07 +00:00
Matthew Dempsky
1624a9c9e7 cmd/compile: get rid of redundant Type helper functions
Replace Isfixedarray, Isslice, and Isinter with the IsArray, IsSlice,
and IsInterface methods added for SSA. Rewrite performed mechanically
using gofmt -w -r "Isfoo(t) -> t.IsFoo()".

Because the IsFoo methods panic when given a nil pointer, a handful of
call sites had to be modified to check for nil Type values. These
aren't strictly necessary, because nil Type values should only occur
in invalid Go source programs, so it would be okay if we panicked on
them and gave up type checking the rest of the package. However, there
are a couple regress tests that expect we continue, so add checks to
keep those tests passing. (See #15029.)

Passes toolstash -cmp.

Change-Id: I511c6ac4cfdf3f9cbdb3e52a5fa91b6d09d82f80
Reviewed-on: https://go-review.googlesource.com/21336
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-30 21:58:18 +00:00
Josh Bleecher Snyder
8640b51df8 cmd/compile: add Type.Elem
This removes almost all direct access to
Type’s heavily overloaded Type field.

Mostly generated by eg, manually checked.

Significant manual changes:

* reflect.go's typPkg used Type indiscriminately.
  Use it only for specific etypes.
* gen.go's visitComponents contained a usage of Type
  with structs. Using Type for structs no longer
  occurs, and the Fatal contained therein has not triggered,
  so it has been axed.
* Scary code in cgen.go's cgen_slice is now explicitly scary.

Passes toolstash -cmp.

Change-Id: I2dbfb3c959da7ae239f964d83898c204affcabc6
Reviewed-on: https://go-review.googlesource.com/21331
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-30 21:21:55 +00:00
Josh Bleecher Snyder
eb98e51563 cmd/compile: add typArray, typSlice, and typDDDArray
These are the first of several convenience
constructors for types.

They are part of type field encapsulation.
This removes most external writes to TARRAY Type and Bound fields.

substAny still directly fiddles with the .Type field.
substAny generally needs access to Type internals.
It will be moved to type.go in a future CL.

bimport still directly writes the .Type field.
This is hard to change.

Also of note:

* inl.go contains an (apparently irrelevant) bug fix:
  as.Right was given the wrong type.
  vararrtype was previously unused.
* I believe that aindex (subr.go) never creates slices,
  but it is safer to keep existing behavior.
  The removal of -1 as a constant there is part
  of hiding that implementation detail.
  Future CLs will finish that job.

Passes toolstash -cmp.

Change-Id: If09bf001a874d7dba08e9ad0bcd6722860af4b91
Reviewed-on: https://go-review.googlesource.com/21249
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-03-29 23:48:24 +00:00
Josh Bleecher Snyder
093a9a1f56 cmd/compile: encapsulate map value type
Passes toolstash -cmp.

Change-Id: I83af544974e1e91e0810e13321afb3e665dcdf12
Reviewed-on: https://go-review.googlesource.com/21248
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-03-29 05:26:32 +00:00
Michel Lespinasse
859b63cc09 cmd/compile: optimize remaining convT2I calls
See #14874
Updates #6853

This change adds a compiler optimization for non pointer shaped convT2I.
Since itab symbols are now emitted by the compiler, the itab address can
be passed directly to convT2I instead of passing the iface type and a
cache pointer argument.

Compilebench results for the 5-commits series ending here:

name       old time/op     new time/op     delta
Template       336ms ± 4%      344ms ± 4%   +2.61%          (p=0.027 n=9+8)
Unicode        165ms ± 6%      173ms ± 7%   +5.11%          (p=0.014 n=9+9)
GoTypes        1.09s ± 1%      1.06s ± 2%   -3.29%          (p=0.000 n=9+9)
Compiler       5.09s ±10%      4.75s ±10%   -6.64%        (p=0.011 n=10+10)
MakeBash       31.1s ± 5%      30.3s ± 3%     ~           (p=0.089 n=10+10)

name       old text-bytes  new text-bytes  delta
HelloSize       558k ± 0%       558k ± 0%   +0.02%        (p=0.000 n=10+10)
CmdGoSize      6.24M ± 0%      6.11M ± 0%   -2.11%        (p=0.000 n=10+10)

name       old data-bytes  new data-bytes  delta
HelloSize      3.66k ± 0%      3.74k ± 0%   +2.41%        (p=0.000 n=10+10)
CmdGoSize       134k ± 0%       162k ± 0%  +20.76%        (p=0.000 n=10+10)

name       old bss-bytes   new bss-bytes   delta
HelloSize       126k ± 0%       126k ± 0%     ~     (all samples are equal)
CmdGoSize       149k ± 0%       146k ± 0%   -2.17%        (p=0.000 n=10+10)

name       old exe-bytes   new exe-bytes   delta
HelloSize       924k ± 0%       924k ± 0%   +0.05%        (p=0.000 n=10+10)
CmdGoSize      9.77M ± 0%      9.62M ± 0%   -1.47%        (p=0.000 n=10+10)

Change-Id: Ib230ddc04988824035c32287ae544a965fedd344
Reviewed-on: https://go-review.googlesource.com/20902
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Michel Lespinasse <walken@google.com>
2016-03-29 02:21:50 +00:00
Michel Lespinasse
7427f2c4bd cmd/compile: optimize convT2I as a two-word copy when T is pointer-shaped
See #14874

This change adds a compiler optimization for pointer shaped convT2I.
Since itab symbols are now emitted by the compiler, the itab address can
be directly moved into the iface structure.

Change-Id: I311483af544519ca682c5f872960717ead772f26
Reviewed-on: https://go-review.googlesource.com/20901
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-03-29 02:21:41 +00:00
Michel Lespinasse
f00bbd5f81 cmd/compile: emit itabs and itablinks
See #14874

This change tells the compiler to emit itab and itablink symbols in
situations where they could be useful; however the compiled code does
not actually make use of the new symbols yet.

Change-Id: I0db3e6ec0cb1f3b7cebd4c60229e4a48372fe586
Reviewed-on: https://go-review.googlesource.com/20888
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Michel Lespinasse <walken@google.com>
2016-03-29 02:18:03 +00:00
Josh Bleecher Snyder
688840593b cmd/compile: don’t generate a new Node for convas
This removes about 3% of the Nodes allocated
while compiling std+cmd.

Passes toolstash -cmp.

name       old time/op     new time/op     delta
Template       320ms ± 3%      316ms ± 5%    ~           (p=0.063 n=21+23)
Unicode        162ms ± 9%      161ms ± 6%    ~           (p=0.788 n=25+25)
GoTypes        1.03s ± 4%      1.03s ± 4%    ~           (p=0.929 n=24+25)
Compiler       4.99s ± 3%      4.95s ± 2%  -0.84%        (p=0.011 n=25+23)
MakeBash       40.3s ± 1%      40.3s ± 1%    ~           (p=0.468 n=24+24)

name       old alloc/op    new alloc/op    delta
Template      57.3MB ± 0%     57.0MB ± 0%  -0.51%        (p=0.000 n=25+23)
Unicode       41.1MB ± 0%     41.0MB ± 0%  -0.27%        (p=0.000 n=25+24)
GoTypes        191MB ± 0%      190MB ± 0%  -0.46%        (p=0.000 n=25+25)
Compiler       839MB ± 0%      834MB ± 0%  -0.62%        (p=0.000 n=24+24)

name       old allocs/op   new allocs/op   delta
Template        500k ± 0%       498k ± 0%  -0.42%        (p=0.000 n=25+25)
Unicode         400k ± 0%       399k ± 0%  -0.22%        (p=0.000 n=24+25)
GoTypes        1.50M ± 0%      1.49M ± 0%  -0.41%        (p=0.000 n=23+25)
Compiler       6.04M ± 0%      6.00M ± 0%  -0.59%        (p=0.000 n=25+25)

Change-Id: I7d3f177d1ab4a75a4c047fa465f2eee38747603f
Reviewed-on: https://go-review.googlesource.com/21178
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-26 23:13:32 +00:00
Josh Bleecher Snyder
babc73547e cmd/compile: remove redundant parameter from finishcompare
This is follow-up 3 of 3 to CL 20959.

Passes toolstash -cmp.

Change-Id: I06efded21bbc970cbefa10e8f2cac1ebc6942e1b
Reviewed-on: https://go-review.googlesource.com/21054
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-24 01:17:47 +00:00
Dave Cheney
a4be24cbe6 cmd/compile/internal/gc: remove redundant Nod(OXXX, ...) pattern
The pattern

    n := Nod(OXXX, nil, nil)
    Nodconst(n, ...)

was a leftover from the C days where n must be heap allocated.

No change in benchmarks, none expected as n escapes anyway.

name      old time/op    new time/op    delta
Template     391ms ± 6%     388ms ± 5%    ~     (p=0.659 n=20+20)
GoTypes      1.27s ± 1%     1.27s ± 2%    ~     (p=0.828 n=18+20)
Compiler     6.16s ± 2%     6.15s ± 1%    ~     (p=0.947 n=20+20)

name      old alloc/op   new alloc/op   delta
Template    63.7MB ± 0%    63.7MB ± 0%    ~     (p=0.414 n=20+20)
GoTypes      219MB ± 0%     219MB ± 0%    ~     (p=0.904 n=20+20)
Compiler     980MB ± 0%     980MB ± 0%  +0.00%  (p=0.007 n=20+19)

name      old allocs/op  new allocs/op  delta
Template      586k ± 0%      586k ± 0%    ~     (p=0.564 n=19+20)
GoTypes      1.80M ± 0%     1.80M ± 0%    ~     (p=0.718 n=20+20)
Compiler     7.74M ± 0%     7.74M ± 0%    ~     (p=0.358 n=20+20)

The reuse of nc in multiple overlapping scopes in walk.go is the worst.

Change-Id: I4ed6a63f7ffbfff68124ad609f6e3a68d95cbbba
Reviewed-on: https://go-review.googlesource.com/21015
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-23 10:59:55 +00:00
Josh Bleecher Snyder
34699bc7a8 cmd/compile: reduce use of **Node parameters
Escape analysis has a hard time with tree-like
structures (see #13493 and #14858).
This is unlikely to change.
As a result, when invoking a function that accepts
a **Node parameter, we usually allocate a *Node
on the heap. This happens a whole lot.

This CL changes functions from taking a **Node
to acting more like append: It both modifies
the input and returns a replacement for it.

Because of the cascading nature of escape analysis,
in order to get the benefits, I had to modify
almost all such functions. The remaining functions
are in racewalk and the backend. I would be happy
to update them as well in a separate CL.

This CL was created by manually updating the
function signatures and the directly impacted
bits of code. The callsites were then automatically
updated using a bespoke script:
https://gist.github.com/josharian/046b1be7aceae244de39

For ease of reviewing and future understanding,
this CL is also broken down into four CLs,
mailed separately, which show the manual
and the automated changes separately.
They are CLs 20990, 20991, 20992, and 20993.

Passes toolstash -cmp.

name       old time/op     new time/op     delta
Template       335ms ± 5%      324ms ± 5%   -3.35%        (p=0.000 n=23+24)
Unicode        176ms ± 9%      165ms ± 6%   -6.12%        (p=0.000 n=23+24)
GoTypes        1.10s ± 4%      1.07s ± 2%   -2.77%        (p=0.000 n=24+24)
Compiler       5.31s ± 3%      5.15s ± 3%   -2.95%        (p=0.000 n=24+24)
MakeBash       41.6s ± 1%      41.7s ± 2%     ~           (p=0.586 n=23+23)

name       old alloc/op    new alloc/op    delta
Template      63.3MB ± 0%     62.4MB ± 0%   -1.36%        (p=0.000 n=25+23)
Unicode       42.4MB ± 0%     41.6MB ± 0%   -1.99%        (p=0.000 n=24+25)
GoTypes        220MB ± 0%      217MB ± 0%   -1.11%        (p=0.000 n=25+25)
Compiler       994MB ± 0%      973MB ± 0%   -2.08%        (p=0.000 n=24+25)

name       old allocs/op   new allocs/op   delta
Template        681k ± 0%       574k ± 0%  -15.71%        (p=0.000 n=24+25)
Unicode         518k ± 0%       413k ± 0%  -20.34%        (p=0.000 n=25+24)
GoTypes        2.08M ± 0%      1.78M ± 0%  -14.62%        (p=0.000 n=25+25)
Compiler       9.26M ± 0%      7.64M ± 0%  -17.48%        (p=0.000 n=25+25)

name       old text-bytes  new text-bytes  delta
HelloSize       578k ± 0%       578k ± 0%     ~     (all samples are equal)
CmdGoSize      6.46M ± 0%      6.46M ± 0%     ~     (all samples are equal)

name       old data-bytes  new data-bytes  delta
HelloSize       128k ± 0%       128k ± 0%     ~     (all samples are equal)
CmdGoSize       281k ± 0%       281k ± 0%     ~     (all samples are equal)

name       old exe-bytes   new exe-bytes   delta
HelloSize       921k ± 0%       921k ± 0%     ~     (all samples are equal)
CmdGoSize      9.86M ± 0%      9.86M ± 0%     ~     (all samples are equal)

Change-Id: I277d95bd56d51c166ef7f560647aeaa092f3f475
Reviewed-on: https://go-review.googlesource.com/20959
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-22 14:11:36 +00:00
Keith Randall
d4663e1353 cmd/compile: don't write back unchanged slice results
Don't write back parts of a slicing operation if they
are unchanged from the source of the slice.  For example:

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

There is more to be done here, for example:

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

This CL can't handle that one yet.

Fixes #14855

Change-Id: Id1e1a4fa7f3076dc1a76924a7f1cd791b81909bb
Reviewed-on: https://go-review.googlesource.com/20954
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
2016-03-21 23:40:18 +00:00
Robert Griesemer
07749aef98 cmd/compile: special-case const comparisons against zero
Constant comparisons against 0 are reasonably common.
Special-case and avoid allocating a new zero value each time.

Change-Id: I6c526c8ab30ef7f0fef59110133c764b7b90ba05
Reviewed-on: https://go-review.googlesource.com/20956
Reviewed-by: Alan Donovan <adonovan@google.com>
2016-03-21 17:58:21 +00:00
Matthew Dempsky
d3253876f2 cmd/compile: change Mp{int,flt} functions into methods
Also give them more idiomatic Go names. Adding godocs is outside the
scope of this CL. (Besides, the method names almost all directly
parallel an underlying math/big.Int or math/big.Float method.)

CL prepared mechanically with sed (for rewriting mpint.go/mpfloat.go)
and gofmt (for rewriting call sites).

Passes toolstash -cmp.

Change-Id: Id76f4aee476ba740f48db33162463e7978c2083d
Reviewed-on: https://go-review.googlesource.com/20909
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-03-21 17:25:50 +00:00
Ian Lance Taylor
a9407b5797 cmd/compile: fix varexpr handling of ODOT
For a long time varexpr has handled ODOT incorrectly: it has always
returned false.  Before https://golang.org/cl/20890 this has been
because an ODOT had a Right field with an ONAME with no Class, for which
varexpr returns false.  CL 20890 preserved the behavior of varexpr for
ODOT, so that the change would pass toolstash -cmp.

This CL fixes varexpr so that ODOT can return true in some cases.  This
breaks toolstash -cmp.  While the changed compiler allocates temporary
variables in a different order, I have not been able to find any
examples where the generated code is different, other than using
different stack offsets and, in some cases, registers.  It seems that
other parts of the compiler will force the ODOT into a temporary anyhow.

Still, this change is clearly correct, and is a minor compiler cleanup.

Change-Id: I71506877aa3c13966bb03c281aa16271ee7fe80a
Reviewed-on: https://go-review.googlesource.com/20907
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-20 18:28:09 +00:00
Josh Bleecher Snyder
ec7c494535 cmd/compile: remove typechecklist
Convert remaining uses to typecheckslice.

Passes toolstash -cmp.

Change-Id: I6ed0877386fb6c0b036e8ee5a228433343855abd
Reviewed-on: https://go-review.googlesource.com/20905
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-20 00:34:42 +00:00
Ian Lance Taylor
5f525ca60d cmd/compile: change ODOT and friends to use Sym, not Right
The Node type ODOT and its variants all represent a selector, with a
simple name to the right of the dot.  Before this change this was
represented by using an ONAME Node in the Right field.  This ONAME node
served no useful purpose.  This CL changes these Node types to store the
symbol in the Sym field instead, thus not requiring allocating a Node
for each selector.

When compiling x/tools/go/types this CL eliminates nearly 5000 calls to
newname and reduces the total number of Nodes allocated by about 6.6%.
It seems to cut compilation time by 1 to 2 percent.

Getting this right was somewhat subtle, and I added two dubious changes
to produce the exact same output as before.  One is to ishairy in
inl.go: the ONAME node increased the cost of ODOT and friends by 1, and
I retained that, although really ODOT is not more expensive than any
other node.  The other is to varexpr in walk.go: because the ONAME in
the Right field of an ODOT has no class, varexpr would always return
false for an ODOT, although in fact for some ODOT's it seemingly ought
to return true; I added an && false for now.  I will send separate CLs,
that will break toolstash -cmp, to clean these up.

This CL passes toolstash -cmp.

Change-Id: I4af8a10cc59078c436130ce472f25abc3a9b2f80
Reviewed-on: https://go-review.googlesource.com/20890
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-19 00:45:09 +00:00
Matthew Dempsky
dbed1c6361 cmd/compile: eliminate NumFields wrapper functions
Change-Id: I3c6035559288cfdc33857216f50241b81932c8a4
Reviewed-on: https://go-review.googlesource.com/20811
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-17 20:43:18 +00:00
Keith Randall
15ed37d7b7 cmd/compile: enforce nowritebarrier in SSA compiler
Make sure we don't generate write barriers in runtime
code that is marked to forbid write barriers.

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

Fixes #14784

Change-Id: I04b6a3b2ac303c19817e932a36a3b006de103aaa
Reviewed-on: https://go-review.googlesource.com/20791
Reviewed-by: Austin Clements <austin@google.com>
2016-03-17 20:13:24 +00:00
Matthew Dempsky
c837761b52 cmd/compile: get rid of Type's {This,In,Out}tuple fields
Boolean expressions involving t.Thistuple were converted to use
t.Recv(), because it's a bit clearer and will hopefully reveal cases
where we could remove redundant calls to t.Recv() (in followup CLs).

The other cases were all converted to use t.Recvs().NumFields(),
t.Params().NumFields(), or t.Results().NumFields().

Change-Id: I4df91762e7dc4b2ddae35995f8dd604a52c09b09
Reviewed-on: https://go-review.googlesource.com/20796
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
2016-03-17 19:38:30 +00:00
Matthew Dempsky
f6bca3f32d cmd/compile: eliminate a bunch of IterFields/IterMethods calls
This is an automated rewrite of all the calls of the form:

    for f, it := IterFields(t); f != nil; f = it.Next() { ... }

Followup CLs will work on cleaning up the remaining cases.

Change-Id: Ic1005ad45ae0b50c63e815e34e507e2d2644ba1a
Reviewed-on: https://go-review.googlesource.com/20794
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-03-17 19:38:15 +00:00
Austin Clements
3e54ca9a46 cmd/compile: omit write barrier when assigning global function
Currently we generate write barriers when the right side of an
assignment is a global function. This doesn't fall into the existing
case of storing an address of a global because we haven't lowered the
function to a pointer yet.

This write barrier is unnecessary, so eliminate it.

Fixes #13901.

Change-Id: Ibc10e00a8803db0fd75224b66ab94c3737842a79
Reviewed-on: https://go-review.googlesource.com/20772
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2016-03-16 22:42:45 +00:00