1004220 - Add a dump() for MResumePoint

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement)

Description

[Dan Gohman [:sunfish]]

Attachment: resumepoint-dump.patch

I recently debugged a tricky bug involving resume points, and found it useful to be able to call dump() on them to see their operands, and to have them show up in the dump() output for MBasicBlocks.

The attached patch implements this, and also moves dump() up to be a virtual function on MNode, which is also a handy place to have a dump() method.

Comment 1

[Nicolas B. Pierron [:nbp]]

Comment on attachment 8415602 [details] [diff] [review]
resumepoint-dump.patch

Review of attachment 8415602 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/jit/MIRGraph.cpp
@@ +1309,5 @@
>          iter->dump(fp);
>      }
> +    for (MResumePointIterator iter(resumePointsBegin()); iter != resumePointsEnd(); iter++) {
> +        iter->dump(fp);
> +    }

nit: I think it makes more sense to see the resume points with the instructions which are capturing them (except for the block one), as we do in the JSONSpewer[1].

[1] http://dxr.mozilla.org/mozilla-central/source/js/src/jit/JSONSpewer.cpp?from=JSONSpewer.cpp#238

Comment 2

[Dan Gohman [:sunfish]]

Attachment: resumepoint-dump.patch

This patch implements your suggestion to print the resume point along with the instruction, and adds printing of the mode and caller block. It's different enough that I'm resubmitting it for review.

Comment 3

[Dan Gohman [:sunfish]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/4cff28c41a2f

Comment 4

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/4cff28c41a2f