cmd/compile: reenable phielim during rewrite
Remove the "optimization" that was causing the issue.
For the following code the "optimization" was
converting v to (OpCopy x) which is wrong because
x doesn't dominate v.
b1:
y = ...
First .. b3
b2:
x = ...
Goto b3
b3:
v = phi x y
... use v ...
That "optimization" is likely no longer needed because
we now have a second opt pass with a dce in between
which removes blocks of type First.
For pkg/tools/linux_amd64/* the binary size drops
from
82142886 to
82060034.
Change-Id: I10428abbd8b32c5ca66fec3da2e6f3686dddbe31
Reviewed-on: https://go-review.googlesource.com/22312
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>