Basic Block Table (BBT)
16/43
status
a
:=
b
+
c
(
i
)
next use
instruction
line
Structure of a
BBT:
…
…
…
…
backward
Suppose that (
i
) is the current instruction:
1)
Move
status
and
next use
of
a
,
b
,
c
from
ST
to
BBT
2)
In
ST
make these changes:
•
Method:
For variable
a
:
Status
:
dead
Next use
:
none
For variables
b
,
c
:
Status
:
live
Next use
:
(
i
)