[turbofan] Revive the useful parts of the SimplifiedOperatorReducer.

[turbofan] Revive the useful parts of the SimplifiedOperatorReducer.

This partially reverts https://codereview.chromium.org/1162563002
because we might actually be able to optimize certain combinations
now due to dead code elimination.

R=titzer@chromium.org

Committed: https://crrev.com/5056c8219aea58a49e500599c6ebdf5e291b9ef4
Cr-Commit-Position: refs/heads/master@{#29277}

[Benedikt Meurer, 2015-06-24 11:52:40]

Hey Ben,

As discussed offline, this revives the unquestionable parts of the
SimplifiedOperatorReducer. Mostly straight forward. Please take a look.

Thanks,
Benedikt

[titzer, 2015-06-24 12:37:27]

lgtm other than maybe an ordering issue.

Thanks, that was fast!

https://codereview.chromium.org/1202263006/diff/1/src/compiler/pipeline.cc
File src/compiler/pipeline.cc (right):

https://codereview.chromium.org/1202263006/diff/1/src/compiler/pipeline.cc#ne...
src/compiler/pipeline.cc:608: AddReducer(data, &graph_reducer, &simple_reducer);
Maybe simplified reducer before value numbering?

[Benedikt Meurer, 2015-06-25 04:05:37]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-06-25 04:05:38]

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/1202263006/#ps20001
(title: "Reordered reducers. REBASE")

[commit-bot: I haz the power, 2015-06-25 04:05:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1202263006/20001

[Benedikt Meurer, 2015-06-25 04:05:54]

https://codereview.chromium.org/1202263006/diff/1/src/compiler/pipeline.cc
File src/compiler/pipeline.cc (right):

https://codereview.chromium.org/1202263006/diff/1/src/compiler/pipeline.cc#ne...
src/compiler/pipeline.cc:608: AddReducer(data, &graph_reducer, &simple_reducer);
On 2015/06/24 12:37:27, titzer wrote:
> Maybe simplified reducer before value numbering?

Done.

[commit-bot: I haz the power, 2015-06-25 04:47:11]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-06-25 04:47:22]

Patchset 2 (id:??) landed as
https://crrev.com/5056c8219aea58a49e500599c6ebdf5e291b9ef4
Cr-Commit-Position: refs/heads/master@{#29277}