63 lines
1.9 KiB
Factor
63 lines
1.9 KiB
Factor
! Copyright (C) 2008, 2009 Slava Pestov.
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! See http://factorcode.org/license.txt for BSD license.
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USING: kernel accessors sequences combinators combinators.short-circuit
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classes vectors compiler.cfg compiler.cfg.instructions compiler.cfg.rpo ;
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IN: compiler.cfg.useless-blocks
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: update-predecessor-for-delete ( bb -- )
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! We have to replace occurrences of bb with bb's successor
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! in bb's predecessor's list of successors.
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dup predecessors>> first [
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[
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2dup eq? [ drop successors>> first ] [ nip ] if
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] with map
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] change-successors drop ;
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: update-successor-for-delete ( bb -- )
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! We have to replace occurrences of bb with bb's predecessor
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! in bb's sucessor's list of predecessors.
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dup successors>> first [
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[
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2dup eq? [ drop predecessors>> first ] [ nip ] if
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] with map
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] change-predecessors drop ;
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: delete-basic-block ( bb -- )
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[ update-predecessor-for-delete ]
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[ update-successor-for-delete ]
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bi ;
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: delete-basic-block? ( bb -- ? )
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{
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[ instructions>> length 1 = ]
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[ predecessors>> length 1 = ]
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[ successors>> length 1 = ]
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[ instructions>> first ##branch? ]
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} 1&& ;
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: delete-useless-blocks ( cfg -- cfg' )
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dup [
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dup delete-basic-block? [ delete-basic-block ] [ drop ] if
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] each-basic-block
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f >>post-order ;
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: delete-conditional? ( bb -- ? )
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dup instructions>> [ drop f ] [
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last class {
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##compare-branch
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##compare-imm-branch
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##compare-float-branch
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} memq? [ successors>> first2 eq? ] [ drop f ] if
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] if-empty ;
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: delete-conditional ( bb -- )
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dup successors>> first 1vector >>successors
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[ but-last \ ##branch new-insn suffix ] change-instructions
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drop ;
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: delete-useless-conditionals ( cfg -- cfg' )
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dup [
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dup delete-conditional? [ delete-conditional ] [ drop ] if
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] each-basic-block
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f >>post-order ;
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