1 ! Copyright (C) 2008, 2010 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: namespaces arrays assocs hashtables kernel accessors fry
4 grouping sorting sets sequences locals
10 compiler.cfg.utilities
11 compiler.cfg.instructions
12 compiler.cfg.predecessors
13 compiler.cfg.gvn.alien
14 compiler.cfg.gvn.avail
15 compiler.cfg.gvn.comparisons
16 compiler.cfg.gvn.graph
18 compiler.cfg.gvn.rewrite
19 compiler.cfg.gvn.slots
21 compiler.cfg.gvn.expressions ;
24 GENERIC: simplify ( insn -- insn' )
26 M: insn simplify dup rewrite [ simplify ] [ ] ?if ;
27 M: array simplify [ simplify ] map ;
30 GENERIC: value-number ( insn -- )
32 M: array value-number [ value-number ] each ;
34 M: alien-call-insn value-number drop ;
35 M: ##callback-inputs value-number drop ;
37 M: ##copy value-number [ src>> vreg>vn ] [ dst>> ] bi set-vn ;
39 : redundant-instruction ( insn vn -- )
42 :: useful-instruction ( insn expr -- )
45 vn expr exprs>vns get set-at
46 insn vn vns>insns get set-at ;
48 : check-redundancy ( insn -- )
49 dup >expr dup exprs>vns get at
50 [ redundant-instruction ] [ useful-instruction ] ?if ;
53 dup inputs>> values [ vreg>vn ] map sift
55 [ drop ] [ first redundant-instruction ] if-empty
56 ] [ drop check-redundancy ] if ;
59 dup defs-vregs length 1 = [ check-redundancy ] [ drop ] if ;
61 : value-numbering-step ( insns -- )
62 [ simplify value-number ] each ;
64 : value-numbering-iteration ( cfg -- )
65 clear-exprs [ value-numbering-step ] simple-analysis ;
67 : determine-value-numbers ( cfg -- )
72 _ value-numbering-iteration
76 : value-numbering ( cfg -- cfg )
78 dup determine-value-numbers
80 cfg-changed predecessors-changed ;