factor/basis/compiler/cfg/write-barrier/write-barrier.factor

65 lines
1.7 KiB
Factor

! Copyright (C) 2008, 2010 Slava Pestov, Daniel Ehrenberg.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors assocs combinators.short-circuit
compiler.cfg.instructions compiler.cfg.rpo kernel namespaces
sequences sets ;
FROM: namespaces => set ;
IN: compiler.cfg.write-barrier
! This pass must run after GC check insertion and scheduling.
SYMBOL: fresh-allocations
SYMBOL: mutated-objects
SYMBOL: copies
: resolve-copy ( src -- dst )
copies get ?at drop ;
GENERIC: eliminate-write-barrier ( insn -- ? )
: fresh-allocation ( vreg -- )
fresh-allocations get conjoin ;
M: ##allot eliminate-write-barrier
dst>> fresh-allocation t ;
: mutated-object ( vreg -- )
resolve-copy mutated-objects get conjoin ;
M: ##set-slot eliminate-write-barrier
obj>> mutated-object t ;
M: ##set-slot-imm eliminate-write-barrier
obj>> mutated-object t ;
: needs-write-barrier? ( insn -- ? )
resolve-copy {
[ fresh-allocations get key? not ]
[ mutated-objects get key? ]
} 1&& ;
M: ##write-barrier eliminate-write-barrier
src>> needs-write-barrier? ;
M: ##write-barrier-imm eliminate-write-barrier
src>> needs-write-barrier? ;
M: gc-map-insn eliminate-write-barrier
fresh-allocations get clear-assoc ;
M: ##copy eliminate-write-barrier
[ src>> resolve-copy ] [ dst>> ] bi copies get set-at t ;
M: insn eliminate-write-barrier drop t ;
: write-barriers-step ( insns -- insns' )
H{ } clone fresh-allocations set
H{ } clone mutated-objects set
H{ } clone copies set
[ eliminate-write-barrier ] filter! ;
: eliminate-write-barriers ( cfg -- cfg )
dup [ write-barriers-step ] simple-optimization ;