A64: Implement support for stack slots in gap resolver

A64: Implement support for stack slots in gap resolver

BUG=none
LOG=y
R=rodolph.perfetta@arm.com, ulan@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=19090

[Rodolph Perfetta (ARM), 2014-02-03 11:13:12]

Tests exercising those code path would be very useful.

https://codereview.chromium.org/138943008/diff/1/src/a64/lithium-gap-resolver...
File src/a64/lithium-gap-resolver-a64.cc (right):

https://codereview.chromium.org/138943008/diff/1/src/a64/lithium-gap-resolver...
src/a64/lithium-gap-resolver-a64.cc:298: __ Ldr(kSavedValue, src);
This won't work, if you are in a cycle kSavedValue is already in use. Have a
look at EmitStackSlotMove to see how it has been dealt with for StackSlot.

[jochen (gone - plz use gerrit), 2014-02-04 14:57:06]

+sven

Sven, any idea how to test this code path?

https://codereview.chromium.org/138943008/diff/1/src/a64/lithium-gap-resolver...
File src/a64/lithium-gap-resolver-a64.cc (right):

https://codereview.chromium.org/138943008/diff/1/src/a64/lithium-gap-resolver...
src/a64/lithium-gap-resolver-a64.cc:298: __ Ldr(kSavedValue, src);
On 2014/02/03 11:13:13, Rodolph Perfetta (ARM) wrote:
> This won't work, if you are in a cycle kSavedValue is already in use. Have a
> look at EmitStackSlotMove to see how it has been dealt with for StackSlot.

Done.

[Rodolph Perfetta (ARM), 2014-02-04 16:32:09]

LGTM with nits addressed.

We'll look if we can add test cases later.

https://codereview.chromium.org/138943008/diff/60001/src/a64/lithium-gap-reso...
File src/a64/lithium-gap-resolver-a64.cc (right):

https://codereview.chromium.org/138943008/diff/60001/src/a64/lithium-gap-reso...
src/a64/lithium-gap-resolver-a64.cc:297:
ASSERT(destination->IsDoubleStackSlot());
How about reusing EmitStackSlotMove define below

[jochen (gone - plz use gerrit), 2014-02-05 08:06:29]

Committed patchset #2 manually as r19090 (presubmit successful).