[turbofan] Narrow upper bounds during typed lowering.

[turbofan] Narrow upper bounds during typed lowering.

This is a temporary solution, which optionally narrows upper bounds of
nodes when changing the operator of a node.

R=jarin@chromium.org

Committed: https://chromium.googlesource.com/v8/v8/+/73b4af7aa69178d8446fc1402032c77462f2c7d6

[Jarin, 2014-12-04 10:43:01]

lgtm with some comments (although I am quite unhappy about the hack).

https://codereview.chromium.org/741503006/diff/1/src/compiler/js-typed-loweri...
File src/compiler/js-typed-lowering.cc (right):

https://codereview.chromium.org/741503006/diff/1/src/compiler/js-typed-loweri...
src/compiler/js-typed-lowering.cc:133: // TODO(jarin): Narrow the type after
patching the operator.
This is not really a big fat TODO. Could you write something like 'Replace the
explicit typing hack with a call to some method that encapsulates changing the
operator and re-typing.'?

https://codereview.chromium.org/741503006/diff/1/src/compiler/js-typed-loweri...
src/compiler/js-typed-lowering.cc:146: }
Insert an empty line here?

[Benedikt Meurer, 2014-12-04 11:19:01]

https://codereview.chromium.org/741503006/diff/1/src/compiler/js-typed-loweri...
File src/compiler/js-typed-lowering.cc (right):

https://codereview.chromium.org/741503006/diff/1/src/compiler/js-typed-loweri...
src/compiler/js-typed-lowering.cc:133: // TODO(jarin): Narrow the type after
patching the operator.
On 2014/12/04 10:43:01, jarin wrote:
> This is not really a big fat TODO. Could you write something like 'Replace the
> explicit typing hack with a call to some method that encapsulates changing the
> operator and re-typing.'?

Done.

https://codereview.chromium.org/741503006/diff/1/src/compiler/js-typed-loweri...
src/compiler/js-typed-lowering.cc:146: }
On 2014/12/04 10:43:01, jarin wrote:
> Insert an empty line here?

Done.

[Benedikt Meurer, 2014-12-04 11:19:46]

Committed patchset #1 (id:1) manually as
73b4af7aa69178d8446fc1402032c77462f2c7d6 (presubmit successful).