[wasm] Int64Lowering of I64Div and I64Rem.

[wasm] Int64Lowering of I64Div and I64Rem.

On 32-bit systems these instructions are compiled to calls to
C functions. The TF node for the function call is already generated in
the wasm compiler, the lowering of the I64 parameters is done in the
Int64Lowering. We use the return value of the C function to determine
whether the calculation should trap or not.

R=titzer@chromium.org

Committed: https://crrev.com/29e0e8e9e3eb7713ab932b155893e78a00dec671
Cr-Commit-Position: refs/heads/master@{#34768}

[Yang, 2016-03-14 10:56:10]

On 2016/03/14 10:55:39, ahaas wrote:

src/snapshot lgtm.

[titzer, 2016-03-14 11:03:22]

lgtm

https://codereview.chromium.org/1804513002/diff/1/src/compiler/wasm-compiler.cc
File src/compiler/wasm-compiler.cc (right):

https://codereview.chromium.org/1804513002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1750: trap_->ZeroCheck64(kTrapDivByZero, right);
Style nit: leave the else clause unnested.

https://codereview.chromium.org/1804513002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1837:
trap_->ZeroCheck32(static_cast<TrapReason>(trap_zero), call);
Can you leave a TODO here? This can get simpler if we have a specialized runtime
call to throw WASM exceptions by trap code instead of by string.

[ahaas, 2016-03-14 12:38:12]

ahaas@chromium.org changed reviewers:
+ yangguo@chromium.org

[ahaas, 2016-03-14 12:38:12]

https://codereview.chromium.org/1804513002/diff/1/src/compiler/wasm-compiler.cc
File src/compiler/wasm-compiler.cc (right):

https://codereview.chromium.org/1804513002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1750: trap_->ZeroCheck64(kTrapDivByZero, right);
On 2016/03/14 at 11:03:22, titzer wrote:
> Style nit: leave the else clause unnested.

Done.

https://codereview.chromium.org/1804513002/diff/1/src/compiler/wasm-compiler....
src/compiler/wasm-compiler.cc:1837:
trap_->ZeroCheck32(static_cast<TrapReason>(trap_zero), call);
On 2016/03/14 at 11:03:22, titzer wrote:
> Can you leave a TODO here? This can get simpler if we have a specialized
runtime call to throw WASM exceptions by trap code instead of by string.

Done.

[ahaas, 2016-03-15 06:31:29]

The CQ bit was checked by ahaas@chromium.org

[ahaas, 2016-03-15 06:31:30]

The patchset sent to the CQ was uploaded after l-g-t-m from titzer@chromium.org,
yangguo@chromium.org
Link to the patchset: https://codereview.chromium.org/1804513002/#ps100001
(title: "Rebase")

[commit-bot: I haz the power, 2016-03-15 06:31:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1804513002/100001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1804513002/100001

[commit-bot: I haz the power, 2016-03-15 06:52:04]

Committed patchset #6 (id:100001)

[commit-bot: I haz the power, 2016-03-15 06:52:59]

Description was changed from

==========
[wasm] Int64Lowering of I64Div and I64Rem.

On 32-bit systems these instructions are compiled to calls to
C functions. The TF node for the function call is already generated in
the wasm compiler, the lowering of the I64 parameters is done in the
Int64Lowering. We use the return value of the C function to determine
whether the calculation should trap or not.

R=titzer@chromium.org
==========

to

==========
[wasm] Int64Lowering of I64Div and I64Rem.

On 32-bit systems these instructions are compiled to calls to
C functions. The TF node for the function call is already generated in
the wasm compiler, the lowering of the I64 parameters is done in the
Int64Lowering. We use the return value of the C function to determine
whether the calculation should trap or not.

R=titzer@chromium.org

Committed: https://crrev.com/29e0e8e9e3eb7713ab932b155893e78a00dec671
Cr-Commit-Position: refs/heads/master@{#34768}
==========

[commit-bot: I haz the power, 2016-03-15 06:53:00]

Patchset 6 (id:??) landed as
https://crrev.com/29e0e8e9e3eb7713ab932b155893e78a00dec671
Cr-Commit-Position: refs/heads/master@{#34768}