code review 5174045: 5g, 6g, 8g: registerize variables again

5g, 6g, 8g: registerize variables again

My previous CL:

changeset:   9645:ce2e5f44b310
user:        Russ Cox <rsc@golang.org>
date:        Tue Sep 06 10:24:21 2011 -0400
summary:     gc: unify stack frame layout

introduced a bug wherein no variables were
being registerized, making Go programs 2-3x
slower than they had been before.

This CL fixes that bug (along with some others
it was hiding) and adds a test that optimization
makes at least one test case faster.

[rsc, 2011-10-03 21:46:34]

Hello ken2 (cc: golang-dev@googlegroups.com),

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

[rsc, 2011-10-03 21:46:40]

*** Submitted as http://code.google.com/p/go/source/detail?r=5321113cd59b ***

5g, 6g, 8g: registerize variables again

My previous CL:

changeset:   9645:ce2e5f44b310
user:        Russ Cox <rsc@golang.org>
date:        Tue Sep 06 10:24:21 2011 -0400
summary:     gc: unify stack frame layout

introduced a bug wherein no variables were
being registerized, making Go programs 2-3x
slower than they had been before.

This CL fixes that bug (along with some others
it was hiding) and adds a test that optimization
makes at least one test case faster.

R=ken2
CC=golang-dev
http://codereview.appspot.com/5174045

[bradfitz, 2011-10-03 21:56:41]

http://codereview.appspot.com/5174045/diff/3001/src/cmd/5g/gsubr.c
File src/cmd/5g/gsubr.c (right):

http://codereview.appspot.com/5174045/diff/3001/src/cmd/5g/gsubr.c#newcode1281
src/cmd/5g/gsubr.c:1281: //if(a->node >= (Node*)&n)
temporary debug code?

[rsc, 2011-10-03 21:58:12]

On Mon, Oct 3, 2011 at 17:56,  <bradfitz@golang.org> wrote:
> temporary debug code?

temporary debug code worth keeping.
i'd leave it enabled if i could be sure
that the test was accurate on all systems.

russ