br_if-to-table (#1313)

Implements #1309: subsequent br_ifs that compare the same value to various constants are converted into a br_table in a block,

(br_if $x (i32.eq (get_local $a) (i32.const 0)))
(br_if $y (i32.eq (get_local $a) (i32.const 1)))
(br_if $z (i32.eq (get_local $a) (i32.const 2)))
  ==>
(block $tablify
 (br_table $x $y $z $tablify
  (get_local $a)
 )
)

The constants for when to apply this (e.g., not if the range of values would make a huge jump table) are fairly conservative, I think, but hard to tell. Probably should be tweaked based on our experience with the pass in practice later on.

0 files changed, 0 insertions, 0 deletions