1 ! Copyright (C) 2008 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors assocs compiler.tree compiler.tree.combinators
4 compiler.tree.def-use compiler.utilities deques dlists kernel
5 namespaces sets stack-checker.branches ;
6 IN: compiler.tree.dead-code.liveness
12 : live-value? ( value -- ? ) live-values get at ;
14 : look-at-value ( values -- ) work-list get push-front ;
16 : look-at-values ( values -- ) work-list get push-all-front ;
18 : look-at-inputs ( node -- ) in-d>> look-at-values ;
20 : init-dead-code ( -- )
21 <hashed-dlist> work-list set
22 H{ { +bottom+ f } } clone live-values set ;
24 GENERIC: mark-live-values* ( node -- )
26 : mark-live-values ( nodes -- nodes )
27 dup [ mark-live-values* ] each-node ; inline
29 M: node mark-live-values* drop ;
31 GENERIC: compute-live-values* ( value node -- )
33 M: node compute-live-values* 2drop ;
35 : iterate-live-values ( value -- )
36 dup live-values get key? [
39 dup live-values get conjoin
40 dup defined-by compute-live-values*
43 : compute-live-values ( -- )
44 work-list get [ iterate-live-values ] slurp-deque ;
46 GENERIC: remove-dead-code* ( node -- node' )
48 M: node remove-dead-code* ;
50 : (remove-dead-code) ( nodes -- nodes' )
51 [ remove-dead-code* ] map-flat ;