Implement more of x64 register allocator.

Implement more of x64 register allocator.

Committed: http://code.google.com/p/v8/source/detail?r=2154

[Lasse Reichstein, 2009-06-12 09:24:30]

LGTM

http://codereview.chromium.org/126043/diff/1/2
File src/x64/register-allocator-x64-inl.h (right):

http://codereview.chromium.org/126043/diff/1/2#newcode41
Line 41: reg.is(kScratchRegister) || reg.is(r12);
See below for r12.

http://codereview.chromium.org/126043/diff/1/2#newcode49
Line 49: static int numbers[] = {
Would it help compiler optimization to make this "const int"?

http://codereview.chromium.org/126043/diff/1/2#newcode62
Line 62: -1,  // r12
No need to exclude r12 (unless you reserve it for something yourself).
We currently disallow r12 as index register, but we shouldn't - it works fine.
I'll post a CL to remove the restriction.

If anything, if we can make r12 and r13 low priority registers (last in line to
get used), it might make code a little smaller, since opcodes using r13 (with no
displacement) or r12 (with no index) as base registers cost an extra byte.

[William Hesse, 2009-06-12 11:12:58]

http://codereview.chromium.org/126043/diff/1/2
File src/x64/register-allocator-x64-inl.h (right):

http://codereview.chromium.org/126043/diff/1/2#newcode41
Line 41: reg.is(kScratchRegister) || reg.is(r12);
On 2009/06/12 09:24:30, Lasse Reichstein wrote:
> See below for r12.
> 

Done.

http://codereview.chromium.org/126043/diff/1/2#newcode49
Line 49: static int numbers[] = {
On 2009/06/12 09:24:30, Lasse Reichstein wrote:
> Would it help compiler optimization to make this "const int"?
> 

Done.

http://codereview.chromium.org/126043/diff/1/2#newcode62
Line 62: -1,  // r12
On 2009/06/12 09:24:30, Lasse Reichstein wrote:
> No need to exclude r12 (unless you reserve it for something yourself).
> We currently disallow r12 as index register, but we shouldn't - it works fine.
> I'll post a CL to remove the restriction.
> 
> If anything, if we can make r12 and r13 low priority registers (last in line
to
> get used), it might make code a little smaller, since opcodes using r13 (with
no
> displacement) or r12 (with no index) as base registers cost an extra byte.

Done.