Closed Bug 674490 Opened 12 years ago Closed 12 years ago

IonMonkey: Be a little lazier about allocating registers in the linear scan register allocator

Categories

(Core :: JavaScript Engine, defect)

Product:
Core
Component:
JavaScript Engine
Type:
defect
Priority:
Not set
Severity:
normal

Tracking

()

Status:
RESOLVED FIXED

People

(Reporter: adrake, Assigned: adrake)

References

Details

Attachments

(1 file)

Patch v0
1.16 KB, patch
dvander
: review+
Details | Diff | Splinter Review 
We allocate registers for intervals which really, really don't need them. A heuristic to prevent this from occurring could eliminate some particularly stupid moves.
Attached patch Patch v0 — — Splinter Review 
This adds a tiny cheap check right before free register allocation. If there are no real (non-KEEPALIVE) uses coming up, and a canonical spill location is already there (no code would be emitted to do the spill), then spill.

There may be an argument for this even if there is no existing canonical spill location, since it's going to get spilled as soon as a register is needed later, anyway. Thoughts?
Attachment #548749 - Flags: review?(dvander)
Comment on attachment 548749 [details] [diff] [review]
Patch v0

Review of attachment 548749 [details] [diff] [review]:
-----------------------------------------------------------------
Attachment #548749 - Flags: review?(dvander) → review+
http://hg.mozilla.org/projects/ionmonkey/rev/3be9cb4bc96a
Status: ASSIGNED → RESOLVED
Closed: 12 years ago
Resolution: --- → FIXED
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