Clean up the Result class. Reduce the size of Result from four words...

Clean up the Result class.  Reduce the size of Result from four words
to one by keeping a stack of active code generators and by using
indirection to handles.

Mainly a cleanup.  No visible performance impact.

Committed: http://code.google.com/p/v8/source/detail?r=1965

[Kevin Millikin (Chromium), 2009-05-15 10:50:49]

LGTM.

http://codereview.chromium.org/113455/diff/1010/1017
File src/codegen.h (right):

http://codereview.chromium.org/113455/diff/1010/1017#newcode99
Line 99: previous = Result::cgen_;
Does the static top code generator belong to the Result?  I can see it being
used elsewhere (JumpTarget).  Maybe it fits better in CodeGeneratorScope or
CodeGenerator.

http://codereview.chromium.org/113455/diff/1010/1014
File src/ia32/codegen-ia32.cc (right):

http://codereview.chromium.org/113455/diff/1010/1014#newcode806
Line 806: Result left;
A separate cleanup, since we have it now, is to use the top code generator in
the deferred code objects.

http://codereview.chromium.org/113455/diff/1010/1012
File src/register-allocator.h (right):

http://codereview.chromium.org/113455/diff/1010/1012#newcode125
Line 125: explicit Result() { invalidate(); }
Doesn't need explicit anymore.

[William Hesse, 2009-05-15 11:02:15]

LGTM.

[Kasper Lund, 2009-05-15 11:04:50]

LGTM.

[Mads Ager (chromium), 2009-05-15 11:05:25]

http://codereview.chromium.org/113455/diff/1010/1017
File src/codegen.h (right):

http://codereview.chromium.org/113455/diff/1010/1017#newcode99
Line 99: previous = Result::cgen_;
On 2009/05/15 10:50:49, Kevin Millikin wrote:
> Does the static top code generator belong to the Result?  I can see it being
> used elsewhere (JumpTarget).  Maybe it fits better in CodeGeneratorScope or
> CodeGenerator.

Good point.  I moved it to the CodeGeneratorScope.  Whenever you need the
current CodeGenerator you can get it as CodeGeneratorScope::Current().

http://codereview.chromium.org/113455/diff/1010/1012
File src/register-allocator.h (right):

http://codereview.chromium.org/113455/diff/1010/1012#newcode125
Line 125: explicit Result() { invalidate(); }
On 2009/05/15 10:50:49, Kevin Millikin wrote:
> Doesn't need explicit anymore.

Done.