-! Copyright (C) 2009, 2010 Slava Pestov.
+! Copyright (C) 2009, 2011 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
-USING: accessors arrays assocs fry kernel namespaces
-sequences sequences.deep
-sets vectors
-cpu.architecture
-compiler.cfg.rpo
-compiler.cfg.def-use
-compiler.cfg.registers
-compiler.cfg.dominance
-compiler.cfg.instructions
-compiler.cfg.liveness.ssa
-compiler.cfg.ssa.cssa
+USING: accessors arrays assocs combinators compiler.cfg.def-use
+compiler.cfg.dominance compiler.cfg.instructions
+compiler.cfg.liveness compiler.cfg.parallel-copy
+compiler.cfg.registers compiler.cfg.rpo compiler.cfg.ssa.cssa
+compiler.cfg.ssa.destruction.leaders
compiler.cfg.ssa.interference
-compiler.cfg.ssa.interference.live-ranges
-compiler.cfg.utilities
-compiler.utilities ;
+compiler.cfg.ssa.interference.live-ranges compiler.cfg.utilities
+cpu.architecture kernel locals make namespaces sequences sets ;
FROM: namespaces => set ;
IN: compiler.cfg.ssa.destruction
-! Because of the design of the register allocator, this pass
-! has three peculiar properties.
-!
-! 1) Instead of renaming vreg usages in the CFG, a map from
-! vregs to canonical representatives is computed. This allows
-! the register allocator to use the original SSA names to get
-! reaching definitions.
-! 2) Useless ##copy instructions, and all ##phi instructions,
-! are eliminated, so the register allocator does not have to
-! remove any redundant operations.
-! 3) A side effect of running this pass is that SSA liveness
-! information is computed, so the register allocator does not
-! need to compute it again.
-
-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
+: value-of ( vreg -- value )
+ dup insn-of dup ##tagged>integer? [ nip src>> ] [ drop ] if ;
+
: init-coalescing ( -- )
- defs get keys
- [ [ dup ] H{ } map>assoc leader-map set ]
- [ [ dup 1vector ] H{ } map>assoc class-element-map set ] bi
+ defs get
+ [ keys unique leader-map set ]
+ [
+ [ [ dup dup value-of ] dip <vreg-info> 1array ] assoc-map
+ class-element-map set
+ ] bi
V{ } clone copies set ;
-: classes-interfere? ( vreg1 vreg2 -- ? )
- [ leader ] bi@ 2dup eq? [ 2drop f ] [
- [ class-elements flatten ] bi@ sets-interfere?
- ] if ;
+: coalesce-elements ( merged vreg1 vreg2 -- )
+ ! delete leader1's class, and set leader2's class to merged.
+ class-element-map get [ delete-at ] [ set-at ] bi-curry bi* ;
-: update-leaders ( vreg1 vreg2 -- )
- swap leader-map get set-at ;
+: coalesce-vregs ( merged leader1 leader2 -- )
+ 2dup swap leader-map get set-at coalesce-elements ;
-: merge-classes ( vreg1 vreg2 -- )
- [ [ class-elements ] bi@ push ]
- [ drop class-element-map get delete-at ] 2bi ;
+GENERIC: prepare-insn ( insn -- )
-: eliminate-copy ( vreg1 vreg2 -- )
- [ leader ] bi@
- 2dup eq? [ 2drop ] [
- [ update-leaders ]
- [ merge-classes ]
- 2bi
- ] if ;
+: maybe-eliminate-copy-later ( dst src -- )
+ 2array copies get push ;
-GENERIC: prepare-insn ( insn -- )
+M: insn prepare-insn drop ;
-: try-to-coalesce ( dst src -- ) 2array copies get push ;
+M: alien-call-insn prepare-insn drop ;
-M: insn prepare-insn
+M: vreg-insn prepare-insn
[ temp-vregs [ leader-map get conjoin ] each ]
[
- [ defs-vreg ] [ uses-vregs ] bi
- 2dup empty? not and [
- first
+ [ defs-vregs ] [ uses-vregs ] bi
+ 2dup [ empty? not ] both? [
+ [ first ] bi@
2dup [ rep-of reg-class-of ] bi@ eq?
- [ try-to-coalesce ] [ 2drop ] if
+ [ maybe-eliminate-copy-later ] [ 2drop ] if
] [ 2drop ] if
] bi ;
M: ##copy prepare-insn
- [ dst>> ] [ src>> ] bi try-to-coalesce ;
+ [ dst>> ] [ src>> ] bi maybe-eliminate-copy-later ;
+
+M: ##parallel-copy prepare-insn
+ values>> [ first2 maybe-eliminate-copy-later ] each ;
+
+: leaders ( vreg1 vreg2 -- vreg1' vreg2' )
+ [ leader ] bi@ ;
+
+: vregs-interfere? ( vreg1 vreg2 -- merged/f ? )
+ [ class-elements ] bi@ sets-interfere? ;
+
+ERROR: vregs-shouldn't-interfere vreg1 vreg2 ;
+
+:: must-eliminate-copy ( vreg1 vreg2 -- )
+ ! Eliminate a copy.
+ vreg1 vreg2 = [
+ vreg1 vreg2 vregs-interfere?
+ [ vreg1 vreg2 vregs-shouldn't-interfere ]
+ [ vreg1 vreg2 coalesce-vregs ]
+ if
+ ] unless ;
M: ##tagged>integer prepare-insn
- [ dst>> ] [ src>> ] bi eliminate-copy ;
+ [ dst>> ] [ src>> ] bi leaders must-eliminate-copy ;
M: ##phi prepare-insn
[ dst>> ] [ inputs>> values ] bi
- [ eliminate-copy ] with each ;
-
-: prepare-block ( bb -- )
- instructions>> [ prepare-insn ] each ;
+ [ leaders must-eliminate-copy ] with each ;
: prepare-coalescing ( cfg -- )
init-coalescing
- [ prepare-block ] each-basic-block ;
+ [ [ prepare-insn ] each ] simple-analysis ;
-: process-copies ( -- )
- copies get [
- 2dup classes-interfere?
- [ 2drop ] [ eliminate-copy ] if
- ] assoc-each ;
+:: maybe-eliminate-copy ( vreg1 vreg2 -- )
+ ! Eliminate a copy if possible.
+ vreg1 vreg2 = [
+ vreg1 vreg2 vregs-interfere?
+ [ drop ] [ vreg1 vreg2 coalesce-vregs ] if
+ ] unless ;
-GENERIC: useful-insn? ( insn -- ? )
+: process-copies ( copies -- )
+ [ leaders maybe-eliminate-copy ] assoc-each ;
+
+: perform-coalescing ( cfg -- )
+ prepare-coalescing copies get process-copies ;
+
+GENERIC: cleanup-insn ( insn -- )
: useful-copy? ( insn -- ? )
- [ dst>> leader ] [ src>> leader ] bi eq? not ; inline
+ [ dst>> ] [ src>> ] bi leaders = not ; inline
-M: ##copy useful-insn? useful-copy? ;
+M: ##copy cleanup-insn
+ dup useful-copy? [ , ] [ drop ] if ;
-M: ##tagged>integer useful-insn? useful-copy? ;
+M: ##parallel-copy cleanup-insn
+ values>> [ leaders ] assoc-map [ first2 = ] reject
+ parallel-copy-rep % ;
-M: ##phi useful-insn? drop f ;
+M: ##tagged>integer cleanup-insn
+ dup useful-copy? [ , ] [ drop ] if ;
-M: insn useful-insn? drop t ;
+M: ##phi cleanup-insn drop ;
-: cleanup-block ( bb -- )
- instructions>> [ useful-insn? ] filter! drop ;
+M: insn cleanup-insn , ;
: cleanup-cfg ( cfg -- )
- [ cleanup-block ] each-basic-block ;
+ [ [ [ cleanup-insn ] each ] V{ } make ] simple-optimization ;
PRIVATE>
-: destruct-ssa ( cfg -- cfg' )
- needs-dominance
-
- dup construct-cssa
- dup compute-defs
- dup compute-ssa-live-sets
- dup compute-live-ranges
- dup prepare-coalescing
- process-copies
- dup cleanup-cfg ;
+: destruct-ssa ( cfg -- )
+ f leader-map set
+ {
+ needs-dominance
+ construct-cssa
+ compute-defs
+ compute-insns
+ compute-live-sets
+ compute-live-ranges
+ perform-coalescing
+ cleanup-cfg
+ compute-live-sets
+ } apply-passes ;
projects / factor.git / blobdiff