code review 7879043: runtime: optimize calls to addroot()

runtime: optimize calls to addroot()

[atom, 2013-03-17 11:35:43]

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

I'd like you to review this change to
https://code.google.com/p/go/

[rsc, 2013-03-18 14:49:44]

I think we can skip the various looking for pointers in these data structures.
The reflect package has it cached in real data structures.

https://codereview.appspot.com/7879043/diff/3001/src/pkg/runtime/mgc0.c
File src/pkg/runtime/mgc0.c (right):

https://codereview.appspot.com/7879043/diff/3001/src/pkg/runtime/mgc0.c#newco...
src/pkg/runtime/mgc0.c:1389: if((byte*)type >= arena_start && (byte*)type <
arena_used)
Throughout, please write these as 

arena_start <= x && x < arena_used

so that all the values are ordered smallest to largest in the comparisons.

[atom, 2013-03-18 16:36:09]

Hello golang-dev@googlegroups.com, rsc@golang.org (cc: dvyukov@google.com,
golang-dev@googlegroups.com),

Please take another look.

[rsc, 2013-03-19 18:44:20]

LGTM

[atom, 2013-03-19 18:57:27]

*** Submitted as https://code.google.com/p/go/source/detail?r=1f90b5850ae2 ***

runtime: optimize calls to addroot()

R=golang-dev, rsc
CC=dvyukov, golang-dev
https://codereview.appspot.com/7879043