[wasm] Fix asm.js semantics for divide by zero in WASM translation.

[wasm] Fix asm.js semantics for divide by zero in WASM translation.

R=ahaas@chromium.org,bradnelson@chromium.org
BUG=

Committed: https://crrev.com/257bdfe5434ea54b8687b51611f62b28952bf326
Cr-Commit-Position: refs/heads/master@{#35134}

[ahaas, 2016-03-30 11:00:38]

https://codereview.chromium.org/1839333002/diff/1/src/compiler/wasm-compiler.cc
File src/compiler/wasm-compiler.cc (right):

https://codereview.chromium.org/1839333002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1803: Node* rem =
d.Phi(MachineRepresentation::kWord32, jsgraph()->Int32Constant(0),
Is it necessary to introduce "rem" here?

https://codereview.chromium.org/1839333002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1814: return graph()->NewNode(m->Uint32Mod(),
left, right, graph()->start());
m->Uint32Div()?

https://codereview.chromium.org/1839333002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1822: 
z.Chain(*control_)?

https://codereview.chromium.org/1839333002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1846: 
z.Chain(*control_)?

[titzer, 2016-03-30 11:15:32]

https://codereview.chromium.org/1839333002/diff/1/src/compiler/wasm-compiler.cc
File src/compiler/wasm-compiler.cc (right):

https://codereview.chromium.org/1839333002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1803: Node* rem =
d.Phi(MachineRepresentation::kWord32, jsgraph()->Int32Constant(0),
On 2016/03/30 11:00:38, ahaas wrote:
> Is it necessary to introduce "rem" here?

Done.

https://codereview.chromium.org/1839333002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1814: return graph()->NewNode(m->Uint32Mod(),
left, right, graph()->start());
On 2016/03/30 11:00:37, ahaas wrote:
> m->Uint32Div()?

Done.

https://codereview.chromium.org/1839333002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1822: 
On 2016/03/30 11:00:37, ahaas wrote:
> z.Chain(*control_)?

It's not necessary to chain the diamond here, because the divide below only
depends on the denominator being nonzero, not the entire control chain.

https://codereview.chromium.org/1839333002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1846: 
On 2016/03/30 11:00:38, ahaas wrote:
> z.Chain(*control_)?

Same as above.

[ahaas, 2016-03-30 11:22:22]

lgtm

[titzer, 2016-03-30 11:33:06]

The CQ bit was checked by titzer@chromium.org

[commit-bot: I haz the power, 2016-03-30 11:33:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1839333002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1839333002/40001

[commit-bot: I haz the power, 2016-03-30 11:37:29]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-03-30 11:37:56]

Description was changed from

==========
[wasm] Fix asm.js semantics for divide by zero in WASM translation.

R=ahaas@chromium.org,bradnelson@chromium.org
BUG=
==========

to

==========
[wasm] Fix asm.js semantics for divide by zero in WASM translation.

R=ahaas@chromium.org,bradnelson@chromium.org
BUG=

Committed: https://crrev.com/257bdfe5434ea54b8687b51611f62b28952bf326
Cr-Commit-Position: refs/heads/master@{#35134}
==========

[commit-bot: I haz the power, 2016-03-30 11:37:57]

Patchset 3 (id:??) landed as
https://crrev.com/257bdfe5434ea54b8687b51611f62b28952bf326
Cr-Commit-Position: refs/heads/master@{#35134}