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 ! ! ! Global value numbering
32 GENERIC: value-number ( insn -- )
34 M: array value-number [ value-number ] each ;
36 M: alien-call-insn value-number drop ;
37 M: ##callback-inputs value-number drop ;
39 M: ##copy value-number [ src>> vreg>vn ] [ dst>> ] bi set-vn ;
41 : redundant-instruction ( insn vn -- )
44 :: useful-instruction ( insn expr -- )
47 vn expr exprs>vns get set-at
48 insn vn vns>insns get set-at ;
50 : check-redundancy ( insn -- )
51 dup >expr dup exprs>vns get at
52 [ redundant-instruction ] [ useful-instruction ] ?if ;
55 dup inputs>> values [ vreg>vn ] map sift
57 [ drop ] [ first redundant-instruction ] if-empty
58 ] [ drop check-redundancy ] if ;
61 dup defs-vregs length 1 = [ check-redundancy ] [ drop ] if ;
63 : value-numbering-step ( insns -- )
64 [ simplify value-number ] each ;
66 : value-numbering-iteration ( cfg -- )
67 clear-exprs [ value-numbering-step ] simple-analysis ;
69 : determine-value-numbers ( cfg -- )
74 _ value-numbering-iteration
78 ! ! ! Global common subexpression elimination
80 GENERIC: gcse ( insn -- insn' )
82 M: array gcse [ gcse ] map ;
84 M: alien-call-insn gcse ;
85 M: ##callback-inputs gcse ;
88 : ?eliminate ( insn vn -- insn' )
91 ] [ drop make-available ] if ;
93 : eliminate-redundancy ( insn -- insn' )
94 dup >expr exprs>vns get at
95 [ ?eliminate ] [ make-available ] if* ;
98 dup inputs>> values [ vreg>vn ] map sift
100 [ first ?eliminate ] unless-empty
101 ] [ drop eliminate-redundancy ] if ;
104 dup defs-vregs length 1 = [ eliminate-redundancy ] when ;
106 : gcse-step ( insns -- insns' )
107 [ simplify gcse ] map flatten ;
109 : eliminate-common-subexpressions ( cfg -- )
111 dup compute-avail-sets
112 [ gcse-step ] simple-optimization ;
114 : value-numbering ( cfg -- cfg )
116 dup determine-value-numbers
117 dup eliminate-common-subexpressions
119 cfg-changed predecessors-changed ;