tree a864a8fa85c931ad48b0e7d1092dffa5bfd007c4
parent 0d80a2b616913f1706e648b4b05513c1e642be26
author Cherry Zhang <cherryyz@google.com> 1544211305 -0500
committer Cherry Zhang <cherryyz@google.com> 1544717776 +0000

passes: handle loads from uninitialized slots in liveness code

LICM's load promotion may sometimes generate loads from
uninitialized stack slots. These loads are used only in Phis.
The dynamic execution won't see those values, but the loads or
the Phis may be recorded live, which is bad.

Work around this by searching for such loads and replace them
with zeros.

Change-Id: Ida4ab731554447f7b3b14c45b276b0b1b2105bf3
Reviewed-on: https://go-review.googlesource.com/c/153239
Reviewed-by: Than McIntosh <thanm@google.com>