-! Copyright (C) 2008, 2010 Slava Pestov.
+! Copyright (C) 2008, 2010 Slava Pestov, 2011 Alex Vondrak
! See http://factorcode.org/license.txt for BSD license.
-USING: namespaces arrays assocs kernel accessors fry grouping
-sorting sets sequences locals
-cpu.architecture
-sequences.deep
-compiler.cfg
-compiler.cfg.rpo
-compiler.cfg.def-use
-compiler.cfg.utilities
-compiler.cfg.instructions
-compiler.cfg.gvn.alien
-compiler.cfg.gvn.comparisons
-compiler.cfg.gvn.graph
-compiler.cfg.gvn.math
-compiler.cfg.gvn.rewrite
-compiler.cfg.gvn.slots
-compiler.cfg.gvn.misc
-compiler.cfg.gvn.expressions ;
+USING: accessors arrays assocs compiler.cfg compiler.cfg.def-use
+compiler.cfg.gvn.avail compiler.cfg.gvn.expressions
+compiler.cfg.gvn.graph compiler.cfg.gvn.rewrite
+compiler.cfg.instructions compiler.cfg.predecessors
+compiler.cfg.rpo compiler.cfg.utilities grouping kernel
+namespaces sequences sequences.deep ;
IN: compiler.cfg.gvn
-GENERIC: process-instruction ( insn -- insn' )
+GENERIC: simplify ( insn -- insn' )
-: redundant-instruction ( insn vn -- insn' )
- [ dst>> ] dip [ swap set-vn ] [ <copy> ] 2bi ;
+M: insn simplify dup rewrite [ simplify ] [ dup >avail-insn-uses ] ?if ;
+M: array simplify [ simplify ] map ;
+M: ##copy simplify ;
-:: useful-instruction ( insn expr -- insn' )
- insn dst>> :> vn
- vn vn set-vn
- vn expr exprs>vns get set-at
- insn vn vns>insns get set-at
- insn ;
+! ! ! Global value numbering
-: check-redundancy ( insn -- insn' )
- dup >expr dup exprs>vns get at
- [ redundant-instruction ] [ useful-instruction ] ?if ;
+GENERIC: value-number ( insn -- )
-M: insn process-instruction
- dup rewrite [ process-instruction ] [ ] ?if ;
+M: array value-number [ value-number ] each ;
-M: foldable-insn process-instruction
- dup rewrite
- [ process-instruction ]
- [ dup defs-vregs length 1 = [ check-redundancy ] when ] ?if ;
+: record-defs ( insn -- ) defs-vregs [ dup set-vn ] each ;
-M: ##copy process-instruction
- dup [ src>> vreg>vn ] [ dst>> ] bi set-vn ;
+M: alien-call-insn value-number record-defs ;
+M: ##callback-inputs value-number record-defs ;
-M: ##phi rewrite
- [ dst>> ] [ inputs>> values [ vreg>vn ] map ] bi
- dup sift
- dup all-equal? [
- nip
- [ drop f ]
- [ first <copy> ] if-empty
- ] [ 3drop f ] if ;
+M: ##copy value-number [ src>> vreg>vn ] [ dst>> ] bi set-vn ;
+
+: redundant-instruction ( insn vn -- )
+ swap dst>> set-vn ;
-M: ##phi process-instruction
- dup rewrite
- [ process-instruction ] [ check-redundancy ] ?if ;
+:: useful-instruction ( insn expr -- )
+ insn dst>> :> vn
+ vn vn set-vn
+ vn expr exprs>vns get set-at
+ insn vn vns>insns get set-at ;
-M: ##phi >expr
- inputs>> values [ vreg>vn ] map \ ##phi prefix ;
+: check-redundancy ( insn -- )
+ dup >expr dup exprs>vns get at
+ [ redundant-instruction ] [ useful-instruction ] ?if ;
-M: array process-instruction
- [ process-instruction ] map ;
+M: ##phi value-number
+ dup inputs>> values [ vreg>vn ] map sift
+ dup all-equal? [
+ [ drop ] [ first redundant-instruction ] if-empty
+ ] [ drop check-redundancy ] if ;
-: value-numbering-step ( insns -- insns' )
- [ process-instruction ] map flatten ;
+M: insn value-number
+ dup defs-vregs length 1 = [ check-redundancy ] [ drop ] if ;
-! XXX there's going to be trouble with certain rewrites that
-! modify the cfg / instructions destructively; namely those in
-! comparisons.factor, alien.factor, and slots.factor
+: value-numbering-step ( insns -- )
+ [ simplify value-number ] each ;
: value-numbering-iteration ( cfg -- )
- clear-exprs
- [ value-numbering-step drop ] simple-analysis ;
+ clear-exprs [ value-numbering-step ] simple-analysis ;
-: identify-redundancies ( cfg -- )
+: determine-value-numbers ( cfg -- )
+ final-iteration? off
init-value-graph
'[
changed? off
changed? get
] loop ;
-: eliminate-redundancies ( cfg -- )
- clear-exprs
- [ value-numbering-step ] simple-optimization ;
+! ! ! Global common subexpression elimination
+
+GENERIC: gcse ( insn -- insn' )
+
+M: array gcse [ gcse ] map ;
-: value-numbering ( cfg -- cfg )
- dup identify-redundancies
- dup eliminate-redundancies
- cfg-changed predecessors-changed ;
+: defs-available ( insn -- insn )
+ dup defs-vregs [ make-available ] each ;
+
+M: alien-call-insn gcse defs-available ;
+M: ##callback-inputs gcse defs-available ;
+M: ##copy gcse defs-available ;
+
+: ?eliminate ( insn vn -- insn' )
+ dup available? [
+ [ dst>> dup make-available ] dip <copy>
+ ] [ drop defs-available ] if ;
+
+: eliminate-redundancy ( insn -- insn' )
+ dup >expr exprs>vns get at >avail-vreg
+ [ ?eliminate ] [ defs-available ] if* ;
+
+M: ##phi gcse
+ dup inputs>> values [ vreg>vn ] map sift
+ dup all-equal? [
+ [ first ?eliminate ] unless-empty
+ ] [ drop eliminate-redundancy ] if ;
+
+M: insn gcse
+ dup defs-vregs length 1 = [ eliminate-redundancy ] when ;
+
+: gcse-step ( insns -- insns' )
+ [ simplify gcse ] map flatten ;
+
+: eliminate-common-subexpressions ( cfg -- )
+ final-iteration? on
+ compute-congruence-classes
+ dup compute-avail-sets
+ [ gcse-step ] simple-optimization ;
+
+: value-numbering ( cfg -- )
+ {
+ needs-predecessors
+ determine-value-numbers
+ eliminate-common-subexpressions
+ cfg-changed
+ predecessors-changed
+ } apply-passes ;