factor/basis/compiler/cfg/branch-splitting/branch-splitting.factor

106 lines
2.9 KiB
Factor

! Copyright (C) 2009, 2011 Doug Coleman, Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors arrays combinators combinators.short-circuit
compiler.cfg compiler.cfg.instructions compiler.cfg.predecessors
compiler.cfg.renaming compiler.cfg.rpo compiler.cfg.utilities
deques dlists fry kernel locals math namespaces sequences sets
vectors ;
IN: compiler.cfg.branch-splitting
: clone-instructions ( insns -- insns' )
[ clone dup rename-insn-temps ] map ;
: clone-basic-block ( bb -- bb' )
<basic-block>
swap
{
[ instructions>> clone-instructions >>instructions ]
[ successors>> clone >>successors ]
[ kill-block?>> >>kill-block? ]
[ number>> >>number ]
} cleave ;
: new-blocks ( bb -- copies )
dup predecessors>> [
[ clone-basic-block ] [ 1vector ] bi*
>>predecessors
] with map ;
: update-predecessor-successors ( copies old-bb -- )
[ predecessors>> swap ] keep
'[ [ _ ] dip update-successors ] 2each ;
:: update-successor-predecessor ( copies old-bb succ -- )
succ predecessors>> dup >array :> ( preds preds' )
preds delete-all
preds' [
dup old-bb eq?
[ drop copies preds push-all ] [ preds push ] if
] each ;
: update-successor-predecessors ( copies old-bb -- )
dup successors>>
[ update-successor-predecessor ] 2with each ;
: split-branch ( bb -- )
[ new-blocks ] keep
[ update-predecessor-successors ]
[ update-successor-predecessors ]
2bi ;
UNION: irrelevant ##peek ##replace ##inc ;
: split-instructions? ( insns -- ? ) [ irrelevant? not ] count 5 <= ;
: short-tail-block? ( bb -- ? )
[ successors>> empty? ] [ instructions>> length 2 = ] bi and ;
: short-block? ( bb -- ? )
! If block is empty, always split
[ predecessors>> length ] [ instructions>> length 1 - ] bi * 10 <= ;
: cond-cond-block? ( bb -- ? )
{
[ predecessors>> length 2 = ]
[ successors>> length 2 = ]
[ instructions>> length 20 <= ]
} 1&& ;
: split-branch? ( bb -- ? )
dup loop-entry? [ drop f ] [
dup predecessors>> length 1 <= [ drop f ] [
{
[ short-block? ]
[ short-tail-block? ]
[ cond-cond-block? ]
} 1||
] if
] if ;
SYMBOL: worklist
SYMBOL: visited
: add-to-worklist ( bb -- )
dup visited get ?adjoin
[ worklist get push-front ] [ drop ] if ;
: init-worklist ( cfg -- )
<dlist> worklist namespaces:set
HS{ } clone visited namespaces:set
entry>> add-to-worklist ;
: split-branches ( cfg -- )
{
[ needs-predecessors ]
[ init-worklist ]
[
! For back-edge?
post-order drop
worklist get [
dup split-branch? [ dup split-branch ] when
successors>> [ add-to-worklist ] each
] slurp-deque
]
[ cfg-changed ]
} cleave ;