factor/unfinished/compiler/tree/cleanup/cleanup.factor

143 lines
4.2 KiB
Factor

! Copyright (C) 2008 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: kernel accessors sequences sequences.deep combinators fry
classes.algebra namespaces assocs math math.private
math.partial-dispatch classes.tuple classes.tuple.private
compiler.tree
compiler.tree.intrinsics
compiler.tree.combinators
compiler.tree.propagation.info
compiler.tree.propagation.branches ;
IN: compiler.tree.cleanup
! A phase run after propagation to finish the job, so to speak.
! Codifies speculative inlining decisions, deletes branches
! marked as never taken, and flattens local recursive blocks
! that do not call themselves.
GENERIC: cleanup* ( node -- node/nodes )
: cleanup ( nodes -- nodes' )
#! We don't recurse into children here, instead the methods
#! do it since the logic is a bit more involved
[ cleanup* ] map flatten ;
: cleanup-folding? ( #call -- ? )
node-output-infos dup empty?
[ drop f ] [ [ literal?>> ] all? ] if ;
: cleanup-folding ( #call -- nodes )
#! Replace a #call having a known result with a #drop of its
#! inputs followed by #push nodes for the outputs.
[
[ node-output-infos ] [ out-d>> ] bi
[ [ literal>> ] dip #push ] 2map
]
[ in-d>> #drop ] bi prefix ;
: cleanup-inlining ( #call -- nodes )
body>> cleanup ;
! Removing overflow checks
: no-overflow-variant ( op -- fast-op )
H{
{ fixnum+ fixnum+fast }
{ fixnum- fixnum-fast }
{ fixnum* fixnum*fast }
{ fixnum-shift fixnum-shift-fast }
} at ;
: remove-overflow-check? ( #call -- ? )
dup word>> no-overflow-variant
[ node-output-infos first class>> fixnum class<= ] [ drop f ] if ;
: remove-overflow-check ( #call -- #call )
[ in-d>> ] [ out-d>> ] [ word>> no-overflow-variant ] tri #call cleanup* ;
: immutable-tuple-boa? ( #call -- ? )
dup word>> \ <tuple-boa> eq? [
dup in-d>> peek node-value-info
literal>> class>> immutable-tuple-class?
] [ drop f ] if ;
: immutable-tuple-boa ( #call -- #call )
\ <immutable-tuple-boa> >>word ;
M: #call cleanup*
{
{ [ dup body>> ] [ cleanup-inlining ] }
{ [ dup cleanup-folding? ] [ cleanup-folding ] }
{ [ dup remove-overflow-check? ] [ remove-overflow-check ] }
{ [ dup immutable-tuple-boa? ] [ immutable-tuple-boa ] }
[ ]
} cond ;
GENERIC: delete-node ( node -- )
M: #call-recursive delete-node
dup label>> [ [ eq? not ] with filter ] change-calls drop ;
M: #return-recursive delete-node
label>> f >>return drop ;
M: node delete-node drop ;
: delete-nodes ( nodes -- ) [ delete-node ] each-node ;
: delete-unreachable-branches ( #branch -- )
dup live-branches>> '[
,
[ [ [ drop ] [ delete-nodes ] if ] 2each ]
[ select-children ]
2bi
] change-children drop ;
: fold-only-branch ( #branch -- node/nodes )
#! If only one branch is live we don't need to branch at
#! all; just drop the condition value.
dup live-children sift dup length 1 =
[ first swap in-d>> #drop prefix ] [ drop ] if ;
SYMBOL: live-branches
: cleanup-children ( #branch -- )
[ [ cleanup ] map ] change-children drop ;
M: #branch cleanup*
{
[ delete-unreachable-branches ]
[ cleanup-children ]
[ fold-only-branch ]
[ live-branches>> live-branches set ]
} cleave ;
: cleanup-phi-in ( phi-in live-branches -- phi-in' )
swap dup empty?
[ nip ] [ flip swap select-children sift flip ] if ;
M: #phi cleanup*
#! Remove #phi function inputs which no longer exist.
live-branches get {
[ '[ , cleanup-phi-in ] change-phi-in-d ]
[ '[ , cleanup-phi-in ] change-phi-in-r ]
[ '[ , cleanup-phi-in ] change-phi-info-d ]
[ '[ , cleanup-phi-in ] change-phi-info-r ]
} cleave
live-branches off ;
: >copy ( node -- #copy ) [ in-d>> ] [ out-d>> ] bi #copy ;
: flatten-recursive ( #recursive -- nodes )
#! convert #enter-recursive and #return-recursive into
#! #copy nodes.
child>>
unclip >copy prefix
unclip-last >copy suffix ;
M: #recursive cleanup*
#! Inline bodies of #recursive blocks with no calls left.
[ cleanup ] change-child
dup label>> calls>> empty? [ flatten-recursive ] when ;
M: node cleanup* ;