code review 6819083: cmd/6g: extend componentgen to small arrays and structs.

cmd/6g: extend componentgen to small arrays and structs.

Fixes issue 4092.

[remyoudompheng, 2012-11-03 10:55:21]

Hello golang-dev@googlegroups.com (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[remyoudompheng, 2012-11-03 11:00:50]

A similar change should probably be done on 5g before submitting.

This change causes very wild variations in stack usage. Typically:

BEFORE
src/pkg/time/format.go:377) TEXT    time.Format+0(SB),$768-56
-/src/pkg/time/format.go:643) TEXT    Parse+0(SB),$1408-72
-/src/pkg/time/time.go:622) TEXT    Since+0(SB),$104-32
-/src/pkg/time/time.go:634) TEXT    Time.AddDate+0(SB),$136-72
-/src/pkg/time/time.go:761) TEXT    Now+0(SB),$40-24

AFTER
+/src/pkg/time/format.go:377) TEXT    Time.Format+0(SB),$776-56
+/src/pkg/time/format.go:643) TEXT    Parse+0(SB),$1448-72
+/src/pkg/time/time.go:622) TEXT    Since+0(SB),$32-32
+/src/pkg/time/time.go:634) TEXT    Time.AddDate+0(SB),$112-72
+/src/pkg/time/time.go:761) TEXT    Now+0(SB),$16-24

BEFORE
-/src/pkg/reflect/value.go:671) TEXT    Value.Elem+0(SB),$232-48
-/src/pkg/reflect/value.go:723) TEXT    Value.Field+0(SB),$96-56
-/src/pkg/reflect/value.go:758) TEXT    Value.FieldByIndex+0(SB),$160-72
-/src/pkg/reflect/value.go:774) TEXT    Value.FieldByName+0(SB),$288-64
-/src/pkg/reflect/value.go:786) TEXT    Value.FieldByNameFunc+0(SB),$280-56
 /src/pkg/reflect/value.go:796) TEXT    Value.Float+0(SB),$32-32
-/src/pkg/reflect/value.go:817) TEXT    Value.Index+0(SB),$200-56

AFTER
+/src/pkg/reflect/value.go:671) TEXT    Value.Elem+0(SB),$112-48
+/src/pkg/reflect/value.go:723) TEXT    Value.Field+0(SB),$72-56
+/src/pkg/reflect/value.go:758) TEXT    Value.FieldByIndex+0(SB),$88-72
+/src/pkg/reflect/value.go:774) TEXT    Value.FieldByName+0(SB),$240-64
+/src/pkg/reflect/value.go:786) TEXT    Value.FieldByNameFunc+0(SB),$232-56
 /src/pkg/reflect/value.go:796) TEXT    Value.Float+0(SB),$32-32
+/src/pkg/reflect/value.go:817) TEXT    Value.Index+0(SB),$128-56

The benchmarks are flaky as usual.

benchmark                 old ns/op    new ns/op    delta
BenchmarkBinaryTree17    9772869000   9662797000   -1.13%
BenchmarkFannkuch11      5742501000   5609392000   -2.32%
BenchmarkGobDecode         31946160     33692400   +5.47%
BenchmarkGobEncode         16677800     21850850  +31.02%
BenchmarkGzip             776093800    779833400   +0.48%
BenchmarkGunzip           201803300    201903100   +0.05%
BenchmarkJSONEncode       142083000     86065550  -39.43%
BenchmarkJSONDecode       236137400    209433200  -11.31%
BenchmarkMandelbrot200      7564245      7563690   -0.01%
BenchmarkParse             11591320     11712850   +1.05%
BenchmarkRevcomp         1697446000   1692028000   -0.32%
BenchmarkTemplate         279893800    228567100  -18.34%

[dave_cheney.net, 2012-11-03 11:56:54]

Could you please hg mail this again.

abort: codereview issue 6819083 is out of date: patch and recent changes
conflict (126c37a9e33c->9f8542052bd7)

[remyoudompheng, 2012-11-03 11:59:17]

Hello golang-dev@googlegroups.com, dave@cheney.net (cc:
golang-dev@googlegroups.com),

Please take another look.

[remyoudompheng, 2012-11-03 12:01:40]

The patch is already based on tip, what do you mean?

[dave_cheney.net, 2012-11-03 22:39:19]

Thank you, I think my tree may be corrupt from using too many flaky airport
WiFi services.
On 3 Nov 2012 23:01, <remyoudompheng@gmail.com> wrote:

> The patch is already based on tip, what do you mean?
>
>
http://codereview.appspot.com/**6819083/<http://codereview.appspot.com/6819083/>
>

[dave_cheney.net, 2012-11-09 07:14:56]

gentle ping.

[rsc, 2012-11-12 20:39:06]

LGTM

https://codereview.appspot.com/6819083/diff/9001/src/cmd/6g/gg.h
File src/cmd/6g/gg.h (right):

https://codereview.appspot.com/6819083/diff/9001/src/cmd/6g/gg.h#newcode82
src/cmd/6g/gg.h:82: void  clearslim(Node*);
tab

https://codereview.appspot.com/6819083/diff/9001/src/cmd/gc/gen.c
File src/cmd/gc/gen.c (right):

https://codereview.appspot.com/6819083/diff/9001/src/cmd/gc/gen.c#newcode692
src/cmd/gc/gen.c:692: ullmancalc(&z);
tab

[remyoudompheng, 2012-11-12 23:08:40]

*** Submitted as http://code.google.com/p/go/source/detail?r=723ce500dd2c ***

cmd/6g: extend componentgen to small arrays and structs.

Fixes issue 4092.

R=golang-dev, dave, rsc
CC=golang-dev
http://codereview.appspot.com/6819083

http://codereview.appspot.com/6819083/diff/9001/src/cmd/6g/gg.h
File src/cmd/6g/gg.h (right):

http://codereview.appspot.com/6819083/diff/9001/src/cmd/6g/gg.h#newcode82
src/cmd/6g/gg.h:82: void  clearslim(Node*);
On 2012/11/12 20:39:06, rsc wrote:
> tab

Done.

http://codereview.appspot.com/6819083/diff/9001/src/cmd/gc/gen.c
File src/cmd/gc/gen.c (right):

http://codereview.appspot.com/6819083/diff/9001/src/cmd/gc/gen.c#newcode692
src/cmd/gc/gen.c:692: ullmancalc(&z);
On 2012/11/12 20:39:06, rsc wrote:
> tab

Done.