Expressions of the form
a_0 + a_1 + a_2 + a_3 + ... + a_n
seem to be reasonably common for cases such as building templates.
However, parsing these expressions results in a n-deep expression tree:
...
/
+
/ \
+ a_2
/ \
a_0 a_1
Traversing this tree during compilation can cause a stack overflow when n is
large.
Instead, for left-associate operations such as add, we now build up an
n-ary node in the parse tree, of the form
n-ary +
/ | \
/ | ... \
a_0 a_1 a_n
The bytecode compiler can now iterate through the child expressions
rather than recursing.
This patch only supports arithmetic operations -- subsequent patches
will enable the same optimization for logical tests and comma
expressions.
Bug: v8:6964
Bug: chromium:724961
Bug: chromium:731861
Bug: chromium:752081
Bug: chromium:771653
Bug: chromium:777302
Change-Id: Ie97e4ce42506fe62a7bc4ffbdaa90a9f698352cb
Reviewed-on: https://chromium-review.googlesource.com/733120
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48920}
52ef2a1c27