1 ! Copyright (C) 2008, 2010 Slava Pestov.
2 ! See https://factorcode.org/license.txt for BSD license.
3 USING: accessors arrays assocs compiler.cfg compiler.cfg.def-use
4 compiler.cfg.instructions compiler.cfg.rpo
5 compiler.cfg.utilities kernel locals namespaces sequences
8 USE: compiler.cfg.value-numbering.alien
9 USE: compiler.cfg.value-numbering.comparisons
10 USE: compiler.cfg.value-numbering.expressions
11 USE: compiler.cfg.value-numbering.folding
12 USE: compiler.cfg.value-numbering.graph
13 USE: compiler.cfg.value-numbering.math
14 USE: compiler.cfg.value-numbering.misc
15 USE: compiler.cfg.value-numbering.rewrite
16 USE: compiler.cfg.value-numbering.slots
18 IN: compiler.cfg.value-numbering
20 GENERIC: process-instruction ( insn -- insn' )
22 : redundant-instruction ( insn vn -- insn' )
23 [ dst>> ] dip [ swap set-vn ] [ <copy> ] 2bi ;
25 :: useful-instruction ( insn expr -- insn' )
27 vn vn vregs>vns get set-at
28 vn expr exprs>vns get set-at
29 insn vn vns>insns get set-at
32 : check-redundancy ( insn -- insn' )
33 dup >expr dup exprs>vns get at
34 [ redundant-instruction ] [ useful-instruction ] ?if ;
36 M: insn process-instruction
37 dup rewrite [ process-instruction ] [ ] ?if ;
39 M: foldable-insn process-instruction
41 [ process-instruction ]
42 [ dup defs-vregs length 1 = [ check-redundancy ] when ] ?if ;
44 M: ##copy process-instruction
45 dup [ src>> vreg>vn ] [ dst>> ] bi set-vn ;
47 M: array process-instruction
48 [ process-instruction ] map ;
50 : value-numbering-step ( insns -- insns' )
52 [ process-instruction ] map flatten ;
54 : value-numbering ( cfg -- )
55 [ [ value-numbering-step ] simple-optimization ]
57 [ predecessors-changed ] tri ;