[turbofan] Project exception value out of calls.

[turbofan] Project exception value out of calls.

TEST=cctest/test-run-jsexceptions

Committed: https://crrev.com/e9e8ac7afc34b6b4ee323790a3d65e956c56e012
Cr-Commit-Position: refs/heads/master@{#27537}

[Michael Starzinger, 2015-03-09 14:50:30]

mstarzinger@chromium.org changed reviewers:
+ bmeurer@chromium.org, titzer@chromium.org

[Michael Starzinger, 2015-03-09 14:50:31]

Currently the exception value inside a catch-block is SSA-wise the same as the
return value of the call. This works for operators that actually return a value
(e.g. JSLoadProperty) but breaks down for nodes that don't (e.g.
JSStoreProperty).

This CL shows how it would look like if we make IfException the projection for
the exception value. The alternative would be to use yet another node
representing that explicit projection. I am not sure which is the cleaner
approach. 

Ben, Benedikt: Opinions? WDYT?

[Benedikt Meurer, 2015-03-10 09:42:08]

As per offline discussion: I think this is the best way to address the problem,
although it has it's own issues.

https://codereview.chromium.org/989123003/diff/20001/src/compiler/instruction...
File src/compiler/instruction-selector.cc (right):

https://codereview.chromium.org/989123003/diff/20001/src/compiler/instruction...
src/compiler/instruction-selector.cc:741: return VisitIfException(node);
MarkAsReference is missing.

[titzer, 2015-03-17 16:11:32]

This approach LGTM

https://codereview.chromium.org/989123003/diff/20001/src/compiler/typer.cc
File src/compiler/typer.cc (left):

https://codereview.chromium.org/989123003/diff/20001/src/compiler/typer.cc#ol...
src/compiler/typer.cc:258: INNER_CONTROL_OP_LIST(DECLARE_CASE)
I like expanding the INNER_CONTROL_OP_LIST but can't we get rid of these two
methods? AFAICT, the Reduce method essentially just wraps a call to TypeNode()
with an UpdateBounds(). Seems dumb.

[Michael Starzinger, 2015-03-31 11:58:45]

Rebased. Comments addressed. Promoting from WIP to solution. PTAL.

https://codereview.chromium.org/989123003/diff/20001/src/compiler/instruction...
File src/compiler/instruction-selector.cc (right):

https://codereview.chromium.org/989123003/diff/20001/src/compiler/instruction...
src/compiler/instruction-selector.cc:741: return VisitIfException(node);
On 2015/03/10 09:42:08, Benedikt Meurer (OOO) wrote:
> MarkAsReference is missing.

Done.

https://codereview.chromium.org/989123003/diff/20001/src/compiler/typer.cc
File src/compiler/typer.cc (left):

https://codereview.chromium.org/989123003/diff/20001/src/compiler/typer.cc#ol...
src/compiler/typer.cc:258: INNER_CONTROL_OP_LIST(DECLARE_CASE)
On 2015/03/17 16:11:32, titzer wrote:
> I like expanding the INNER_CONTROL_OP_LIST but can't we get rid of these two
> methods? AFAICT, the Reduce method essentially just wraps a call to TypeNode()
> with an UpdateBounds(). Seems dumb.

Acknowledged. Happy to do that, would it be OK with you if I do that in a
follow-up CL?

[Michael Starzinger, 2015-03-31 12:20:59]

The CQ bit was checked by mstarzinger@chromium.org

[Michael Starzinger, 2015-03-31 12:20:59]

The patchset sent to the CQ was uploaded after l-g-t-m from titzer@chromium.org
Link to the patchset: https://codereview.chromium.org/989123003/#ps60001 (title:
"Addressed comments.")

[commit-bot: I haz the power, 2015-03-31 12:21:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/989123003/60001

[commit-bot: I haz the power, 2015-03-31 12:26:31]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-03-31 12:26:47]

Patchset 4 (id:??) landed as
https://crrev.com/e9e8ac7afc34b6b4ee323790a3d65e956c56e012
Cr-Commit-Position: refs/heads/master@{#27537}