! Copyright (C) 2009, 2011 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
-USING: accessors arrays assocs fry locals kernel make
-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
-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.parallel-copy
-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) This pass computes live sets and fills out GC maps with
-! compiler.cfg.liveness, so the linear scan register allocator
-! does not need to compute liveness again.
-
-! Maps leaders to equivalence class elements.
SYMBOL: class-element-map
: class-elements ( vreg -- elts ) class-element-map get at ;
: init-coalescing ( -- )
defs get
- [ [ drop dup ] assoc-map leader-map set ]
- [ [ [ dup dup value-of ] dip <vreg-info> 1array ] assoc-map class-element-map set ] bi
+ [ keys unique leader-map set ]
+ [
+ [ [ dup dup value-of ] dip <vreg-info> 1array ] assoc-map
+ class-element-map set
+ ] bi
V{ } clone copies set ;
-: coalesce-leaders ( vreg1 vreg2 -- )
- ! leader2 becomes the leader.
- swap leader-map get set-at ;
-
: 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* ;
: coalesce-vregs ( merged leader1 leader2 -- )
- [ coalesce-leaders ] [ coalesce-elements ] 2bi ;
+ 2dup swap leader-map get set-at coalesce-elements ;
GENERIC: prepare-insn ( insn -- )
:: must-eliminate-copy ( vreg1 vreg2 -- )
! Eliminate a copy.
- vreg1 vreg2 eq? [
+ vreg1 vreg2 = [
vreg1 vreg2 vregs-interfere?
[ vreg1 vreg2 vregs-shouldn't-interfere ]
[ vreg1 vreg2 coalesce-vregs ]
:: maybe-eliminate-copy ( vreg1 vreg2 -- )
! Eliminate a copy if possible.
- vreg1 vreg2 eq? [
+ vreg1 vreg2 = [
vreg1 vreg2 vregs-interfere?
[ drop ] [ vreg1 vreg2 coalesce-vregs ] if
] unless ;
-: process-copies ( -- )
- copies get [ leaders maybe-eliminate-copy ] assoc-each ;
+: 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>> ] [ src>> ] bi leaders eq? not ; inline
+ [ dst>> ] [ src>> ] bi leaders = not ; inline
M: ##copy cleanup-insn
dup useful-copy? [ , ] [ drop ] if ;
M: ##parallel-copy cleanup-insn
- values>>
- [ first2 leaders 2array ] map [ first2 eq? not ] filter
- [ parallel-copy-rep ] unless-empty ;
+ values>> [ leaders ] assoc-map [ first2 = ] reject
+ parallel-copy-rep % ;
M: ##tagged>integer cleanup-insn
dup useful-copy? [ , ] [ drop ] if ;
PRIVATE>
-: destruct-ssa ( cfg -- cfg' )
- needs-dominance
-
- dup construct-cssa
- dup compute-defs
- dup compute-insns
- dup compute-live-sets
- dup compute-live-ranges
- dup prepare-coalescing
- process-copies
- dup cleanup-cfg
- dup compute-live-sets ;
+: 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 ;