673026 - IonMonkey: Phis are not inserted in some branch conditions

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Andrew Drake [:adrake]]

In test case:

function branchy(v0,v1) {
 var result = 0;
 if (v0 & v1) {
  result = v0 & v0;
 } else {
  result = v1 & v0;
 }
 return result;
}
branchy(379,1)

no phis are inserted, but at least one should be inserted on the return.

The first bad revision is:
changeset:   72960:c7f8e17bc91c
user:        David Anderson <[e-mail]>
date:        Mon Jul 18 17:43:09 2011 -0700
summary:     Remove snapshots from IR, attach to nodes directly (bug 669984 part 4, r=adrake).

Comment 1

[David Anderson [:dvander] - inactive, e-mail if emergency]

Attachment: fix

This broke because snapshots stopped placing an implicit first instruction in the block, so we need a new way to test whether the block has had its first predecessor set.

Comment 2

[David Anderson [:dvander] - inactive, e-mail if emergency]

http://hg.mozilla.org/projects/ionmonkey/rev/7605afbb47bb