[turbofan] Remove int32 add/subtract narrowing during typed lowering.

[turbofan] Remove int32 narrowing during typed lowering.

With Int32Add we lose the int/uint distinction, so later, in simplified lowering we can make a wrong decision. E.g., see the attached test case, where we lower NumberAdd -> Int32Add because inputs are Uint32, but during simplified lowering we change the inputs to Int32, so we get a wrong result.

Simplified lowering will lower the NumberAdd operations anyway, so we should lose performance.

BUG=
R=bmeurer@chromium.org

Committed: https://chromium.googlesource.com/v8/v8/+/c3af691e72b7b9003c89caa7c43490ce3d3e6c65

[Jarin, 2014-11-14 14:19:47]

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

[Jarin, 2014-11-14 14:21:38]

Could you take a look please?

[titzer, 2014-11-14 14:26:20]

https://codereview.chromium.org/721723004/diff/1/test/cctest/compiler/test-js...
File test/cctest/compiler/test-js-typed-lowering.cc (right):

https://codereview.chromium.org/721723004/diff/1/test/cctest/compiler/test-js...
test/cctest/compiler/test-js-typed-lowering.cc:1216: TEST(Int32AddLowering) {
I think we should keep these tests but assert now that they are
NumberAdd/NumberSubtract.

[Benedikt Meurer, 2014-11-16 11:23:38]

LGTM

[Jarin, 2014-11-17 09:04:57]

Committed patchset #2 (id:20001) manually as
c3af691e72b7b9003c89caa7c43490ce3d3e6c65 (presubmit successful).