factor/basis/compiler/cfg/ssa/destruction/destruction.factor

118 lines
2.9 KiB
Factor

! Copyright (C) 2009 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors arrays assocs fry kernel namespaces
sequences sequences.deep
sets vectors
compiler.cfg.rpo
compiler.cfg.def-use
compiler.cfg.renaming
compiler.cfg.registers
compiler.cfg.dominance
compiler.cfg.instructions
compiler.cfg.liveness.ssa
compiler.cfg.ssa.cssa
compiler.cfg.ssa.interference
compiler.cfg.ssa.interference.live-ranges
compiler.cfg.utilities
compiler.utilities ;
IN: compiler.cfg.ssa.destruction
! Maps vregs to leaders.
SYMBOL: leader-map
: leader ( vreg -- vreg' ) leader-map get compress-path ;
! Maps leaders to equivalence class elements.
SYMBOL: class-element-map
: class-elements ( vreg -- elts ) class-element-map get at ;
! Sequence of vreg pairs
SYMBOL: copies
: init-coalescing ( -- )
H{ } clone leader-map set
H{ } clone class-element-map set
V{ } clone copies set ;
: classes-interfere? ( vreg1 vreg2 -- ? )
[ leader ] bi@ 2dup eq? [ 2drop f ] [
[ class-elements flatten ] bi@ sets-interfere?
] if ;
: update-leaders ( vreg1 vreg2 -- )
swap leader-map get set-at ;
: merge-classes ( vreg1 vreg2 -- )
[ [ class-elements ] bi@ push ]
[ drop class-element-map get delete-at ] 2bi ;
: eliminate-copy ( vreg1 vreg2 -- )
[ leader ] bi@
2dup eq? [ 2drop ] [
[ update-leaders ]
[ merge-classes ]
2bi
] if ;
: introduce-vreg ( vreg -- )
[ leader-map get conjoin ]
[ [ 1vector ] keep class-element-map get set-at ] bi ;
GENERIC: prepare-insn ( insn -- )
: try-to-coalesce ( dst src -- ) 2array copies get push ;
M: insn prepare-insn
[ defs-vreg ] [ uses-vregs ] bi
2dup empty? not and [
first
2dup [ rep-of ] bi@ eq?
[ try-to-coalesce ] [ 2drop ] if
] [ 2drop ] if ;
M: ##copy prepare-insn
[ dst>> ] [ src>> ] bi try-to-coalesce ;
M: ##phi prepare-insn
[ dst>> ] [ inputs>> values ] bi
[ eliminate-copy ] with each ;
: prepare-block ( bb -- )
instructions>> [ prepare-insn ] each ;
: prepare-coalescing ( cfg -- )
init-coalescing
defs get keys [ introduce-vreg ] each
[ prepare-block ] each-basic-block ;
: process-copies ( -- )
copies get [
2dup classes-interfere?
[ 2drop ] [ eliminate-copy ] if
] assoc-each ;
: useless-copy? ( ##copy -- ? )
dup ##copy? [ [ dst>> ] [ src>> ] bi eq? ] [ drop f ] if ;
: perform-renaming ( cfg -- )
leader-map get keys [ dup leader ] H{ } map>assoc renamings set
[
instructions>> [
[ rename-insn-defs ]
[ rename-insn-uses ]
[ [ useless-copy? ] [ ##phi? ] bi or not ] tri
] filter! drop
] each-basic-block ;
: destruct-ssa ( cfg -- cfg' )
needs-dominance
dup construct-cssa
dup compute-defs
compute-ssa-live-sets
dup compute-live-ranges
dup prepare-coalescing
process-copies
dup perform-renaming ;