1 ! Copyright (C) 2009, 2010 Slava Pestov.
2 ! See https://factorcode.org/license.txt for BSD license.
3 USING: accessors arrays combinators combinators.short-circuit
4 compiler.cfg.dominance compiler.cfg.ssa.interference.live-ranges
5 kernel locals math math.order sequences sorting.slots ;
6 IN: compiler.cfg.ssa.interference
8 TUPLE: vreg-info vreg value def-index bb pre-of color equal-anc-in equal-anc-out ;
10 :: <vreg-info> ( vreg value bb -- info )
16 vreg bb def-index >>def-index ;
20 ! Our dominance pass computes dominance information on a
21 ! per-basic block level. Rig up a more fine-grained dominance
23 : locally-dominates? ( vreg1 vreg2 -- ? )
24 [ def-index>> ] bi@ < ;
26 :: vreg-dominates? ( vreg1 vreg2 -- ? )
30 [ vreg1 vreg2 locally-dominates? ] [ bb1 bb2 dominates? ] if ;
32 ! Testing individual vregs for live range intersection.
33 : kill-after-def? ( vreg1 vreg2 bb -- ? )
34 ! If first register is used after second one is defined, they interfere.
35 ! If they are used in the same instruction, no interference. If the
36 ! instruction is a def-is-use-insn, then there will be a use at +1
37 ! (instructions are 2 apart) and so outputs will interfere with
39 [ kill-index ] [ def-index ] bi-curry bi* > ;
41 : interferes-first-dominates? ( vreg1 vreg2 -- ? )
42 ! If vreg1 dominates vreg2, then they interfere if vreg2's definition
43 ! occurs before vreg1 is killed.
44 [ [ vreg>> ] bi@ ] [ nip bb>> ] 2bi kill-after-def? ;
46 : interferes-second-dominates? ( vreg1 vreg2 -- ? )
47 ! If vreg2 dominates vreg1, then they interfere if vreg1's definition
48 ! occurs before vreg2 is killed.
49 swap interferes-first-dominates? ;
51 : interferes-same-block? ( vreg1 vreg2 -- ? )
52 ! If both are defined in the same basic block, they interfere if their
53 ! local live ranges intersect.
54 2dup locally-dominates? [ swap ] unless
55 interferes-first-dominates? ;
57 :: vregs-intersect? ( vreg1 vreg2 -- ? )
61 { [ bb1 bb2 eq? ] [ vreg1 vreg2 interferes-same-block? ] }
62 { [ bb1 bb2 dominates? ] [ vreg1 vreg2 interferes-first-dominates? ] }
63 { [ bb2 bb1 dominates? ] [ vreg1 vreg2 interferes-second-dominates? ] }
67 ! Value-based interference test.
68 : chain-intersect ( vreg1 vreg2 -- vreg )
69 [ 2dup { [ nip ] [ vregs-intersect? not ] } 2&& ]
73 : update-equal-anc-out ( vreg1 vreg2 -- )
74 dupd chain-intersect >>equal-anc-out drop ;
76 : same-sets? ( vreg1 vreg2 -- ? )
79 : same-values? ( vreg1 vreg2 -- ? )
82 : vregs-interfere? ( vreg1 vreg2 -- ? )
83 [ f >>equal-anc-out ] dip
85 2dup same-sets? [ equal-anc-out>> ] when
88 [ update-equal-anc-out f ] [ chain-intersect >boolean ] if ;
90 ! Merging lists of vregs sorted by dominance.
91 M: vreg-info <=> ( vreg1 vreg2 -- <=> )
92 { { pre-of>> <=> } { def-index>> <=> } } compare-slots ;
96 TUPLE: iterator seq n ;
97 : <iterator> ( seq -- iterator ) 0 iterator boa ; inline
98 : done? ( iterator -- ? ) [ seq>> length ] [ n>> ] bi = ; inline
99 : this ( iterator -- obj ) [ n>> ] [ seq>> ] bi nth ; inline
100 : ++ ( iterator -- ) [ 1 + ] change-n drop ; inline
101 : take ( iterator -- obj ) [ this ] [ ++ ] bi ; inline
103 : blue-smaller? ( blue red -- ? )
104 [ this ] bi@ before? ; inline
106 : take-blue? ( blue red -- ? )
117 : merge-sets ( blue red -- seq )
119 [ 2dup [ done? ] both? not ]
122 [ over take blue >>color ]
123 [ dup take red >>color ]
127 : update-for-merge ( seq -- )
129 dup [ equal-anc-in>> ] [ equal-anc-out>> ] bi
130 2dup and [ [ vreg-dominates? ] most ] [ or ] if
135 ! Linear-time live range intersection test in a merged set.
136 : find-parent ( dom current -- vreg )
137 over empty? [ 2drop f ] [
138 over last over vreg-dominates?
139 [ drop last ] [ over pop* find-parent ] if
142 :: linear-interference-test ( seq -- ? )
146 { [ ] [ vreg same-sets? not ] [ vreg swap vregs-interfere? ] } 1&&
147 [ t ] [ vreg dom push f ] if
150 : sets-interfere-1? ( seq1 seq2 -- merged/f ? )
152 2dup before? [ swap ] unless
157 2dup vregs-intersect?
158 [ 2drop f t ] [ 2array f ] if
163 : sets-interfere? ( seq1 seq2 -- merged/f ? )
164 2dup [ length 1 = ] both? [ sets-interfere-1? ] [
165 merge-sets dup linear-interference-test
166 [ drop f t ] [ dup update-for-merge f ] if