commit 42667bab5b310b26bfc0ceb300550696cfbbb3ae
author Adam Klein <adamk@chromium.org> Thu Jan 11 19:49:06 2018
committer Commit Bot <commit-bot@chromium.org> Fri Jan 12 23:55:06 2018
tree 960543b075c3d6d9cd9cdf6322c658dcf3cb0bd9
parent 49898aad76cb2101e599078eb8d4e55836969484

Simplify FunctionKind, saving 4 bits in SharedFunctionInfo

Since we only need to store 18 different function kinds,
the bitfield approach was wasting space (requiring 11 bits).

This patch replaces the bitfield with a regular enum, and
updates all the FunctionKind predicates to use comparisons
instead of bitwise ops.

For the small amount of builtin code that depended upon being
able to do masking to determine whether something is a class
constructor, we still store two extra bits on FunctionKind,
which are computed when the SFI is initialized.

If this approach causes performance regressions (i.e., if it
turns out that other code was implicitly depending on masking
for fast checks), we can revert this or address it in
other ways (e.g., by doing similar caching of repeated checks
in the caller).

Change-Id: Iebb3214f564ea8bd7b21e78fda33517d63247124
Reviewed-on: https://chromium-review.googlesource.com/860896
Commit-Queue: Adam Klein <adamk@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50559}