Experimental: begin using the register allocator across entering and...

Experimental: begin using the register allocator across entering and
leaving with statements.

This requires more care with the use of the context (esi on IA32)
register and the frame slot allocated for saving it.

Committed: http://code.google.com/p/v8/source/detail?r=1027

[William Hesse, 2009-01-06 12:04:07]

LGTM, with comments.

http://codereview.chromium.org/16512/diff/6/207
File src/codegen-ia32.cc (right):

http://codereview.chromium.org/16512/diff/6/207#newcode1677
Line 1677: __ cmp(context.reg(), Operand(esi));
Can't context.Unuse() go directly after the cmp instruction?

http://codereview.chromium.org/16512/diff/6/206
File src/virtual-frame-ia32.h (right):

http://codereview.chromium.org/16512/diff/6/206#newcode284
Line 284: // Save the value of the esi register in the context frame slot.
Comment should say that that esi is not synced to memory until spilled.
// Save the esi register to the virtual context frame slot.
// The value is not written to memory until synced.
Should the code optimize the case where the context slot is already esi?

[Kevin Millikin (Chromium), 2009-01-06 12:10:28]

http://codereview.chromium.org/16512/diff/6/207
File src/codegen-ia32.cc (right):

http://codereview.chromium.org/16512/diff/6/207#newcode1677
Line 1677: __ cmp(context.reg(), Operand(esi));
On 2009/01/06 12:04:08, William Hesse wrote:
> Can't context.Unuse() go directly after the cmp instruction?

Yes.  Fixed.

http://codereview.chromium.org/16512/diff/6/206
File src/virtual-frame-ia32.h (right):

http://codereview.chromium.org/16512/diff/6/206#newcode284
Line 284: // Save the value of the esi register in the context frame slot.
On 2009/01/06 12:04:08, William Hesse wrote:
> Comment should say that that esi is not synced to memory until spilled.
> // Save the esi register to the virtual context frame slot.
> // The value is not written to memory until synced.
> Should the code optimize the case where the context slot is already esi?

Comment changed.