1 ! Copyright (C) 2009 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors assocs combinators compiler.cfg
4 compiler.cfg.instructions compiler.cfg.parallel-copy
5 compiler.cfg.registers compiler.cfg.stacks.height kernel make
6 math math.order namespaces sequences sets ;
7 FROM: namespaces => set ;
8 IN: compiler.cfg.stacks.local
10 ! Local stack analysis. We build three sets for every basic block
12 ! - peek-set: all stack locations that the block reads before writing
13 ! - replace-set: all stack locations that the block writes
14 ! - kill-set: all stack locations which become unavailable after the
15 ! block ends because of the stack height being decremented
16 ! This is done while constructing the CFG.
18 SYMBOLS: peek-sets replace-sets kill-sets ;
22 : loc>vreg ( loc -- vreg ) locs>vregs get [ drop next-vreg ] cache ;
23 : vreg>loc ( vreg -- loc/f ) locs>vregs get value-at ;
29 { emit-r initial: 0 } ;
31 SYMBOLS: local-peek-set local-replace-set replace-mapping ;
33 GENERIC: translate-local-loc ( loc -- loc' )
34 M: ds-loc translate-local-loc n>> current-height get d>> - <ds-loc> ;
35 M: rs-loc translate-local-loc n>> current-height get r>> - <rs-loc> ;
37 : emit-stack-changes ( -- )
38 replace-mapping get dup assoc-empty? [ drop ] [
39 [ [ loc>vreg ] dip ] assoc-map parallel-copy
42 : emit-height-changes ( -- )
44 [ emit-d>> dup 0 = [ drop ] [ ##inc-d, ] if ]
45 [ emit-r>> dup 0 = [ drop ] [ ##inc-r, ] if ] bi ;
48 ! Insert height and stack changes prior to the last instruction
54 ! inc-d/inc-r: these emit ##inc-d/##inc-r to change the stack height later
57 [ [ + ] change-emit-d drop ]
58 [ [ + ] change-d drop ]
63 [ [ + ] change-emit-r drop ]
64 [ [ + ] change-r drop ]
67 : peek-loc ( loc -- vreg )
69 dup replace-mapping get at
70 [ ] [ dup local-peek-set get conjoin loc>vreg ] ?if ;
72 : replace-loc ( vreg loc -- )
73 translate-local-loc replace-mapping get set-at ;
75 : compute-local-kill-set ( -- assoc )
76 basic-block get current-height get
77 [ [ ds-heights get at dup ] [ d>> ] bi* [-] iota [ swap - <ds-loc> ] with map ]
78 [ [ rs-heights get at dup ] [ r>> ] bi* [-] iota [ swap - <rs-loc> ] with map ] 2bi
81 : begin-local-analysis ( -- )
82 H{ } clone local-peek-set set
83 H{ } clone replace-mapping set
85 [ 0 >>emit-d 0 >>emit-r drop ]
86 [ [ d>> ] [ r>> ] bi basic-block get record-stack-heights ] bi ;
88 : remove-redundant-replaces ( -- )
89 replace-mapping get [ [ loc>vreg ] dip = not ] assoc-filter
90 [ replace-mapping set ] [ keys unique local-replace-set set ] bi ;
92 : end-local-analysis ( -- )
93 remove-redundant-replaces
96 [ [ local-peek-set get ] dip peek-sets get set-at ]
97 [ [ local-replace-set get ] dip replace-sets get set-at ]
98 [ [ compute-local-kill-set ] dip kill-sets get set-at ]
101 : clone-current-height ( -- )
102 current-height [ clone ] change ;
104 : peek-set ( bb -- assoc ) peek-sets get at ;
105 : replace-set ( bb -- assoc ) replace-sets get at ;
106 : kill-set ( bb -- assoc ) kill-sets get at ;