factor/basis/compiler/codegen/gc-maps/gc-maps.factor

123 lines
3.4 KiB
Factor

! Copyright (C) 2011 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors arrays assocs bit-arrays combinators
combinators.short-circuit compiler.cfg.instructions
compiler.codegen.relocation cpu.architecture fry kernel layouts
make math math.order namespaces sequences ;
IN: compiler.codegen.gc-maps
! GC maps
! Every code block either ends with
!
! uint 0
!
! or
!
! bitmap, byte aligned, three subsequences:
! - <scrubbed data stack locations>
! - <scrubbed retain stack locations>
! - <GC root spill slots>
! uint[] <base pointers>
! uint[] <return addresses>
! uint <largest scrubbed data stack location>
! uint <largest scrubbed retain stack location>
! uint <largest GC root spill slot>
! uint <largest derived root spill slot>
! int <number of return addresses>
SYMBOLS: return-addresses gc-maps ;
: gc-map-needed? ( gc-map -- ? )
! If there are no stack locations to scrub and no GC roots,
! there's no point storing the GC map.
dup [
{
[ scrub-d>> empty? ]
[ scrub-r>> empty? ]
[ gc-roots>> empty? ]
[ derived-roots>> empty? ]
} 1&& not
] when ;
: gc-map-here ( gc-map -- )
dup gc-map-needed? [
gc-maps get push
compiled-offset return-addresses get push
] [ drop ] if ;
: longest ( seqs -- n )
[ length ] [ max ] map-reduce ;
: emit-scrub ( seqs -- n )
! seqs is a sequence of sequences of 0/1
dup longest
[ '[ [ 0 = ] ?{ } map-as _ f pad-tail % ] each ] keep ;
: integers>bits ( seq n -- bit-array )
<bit-array> [ '[ [ t ] dip _ set-nth ] each ] keep ;
: largest-spill-slot ( seqs -- n )
[ [ 0 ] [ supremum 1 + ] if-empty ] [ max ] map-reduce ;
: emit-gc-roots ( seqs -- n )
! seqs is a sequence of sequences of integers 0..n-1
dup largest-spill-slot
[ '[ _ integers>bits % ] each ] keep ;
: emit-uint ( n -- )
building get push-uint ;
: emit-uints ( n -- )
[ emit-uint ] each ;
: gc-root-offsets ( gc-map -- offsets )
gc-roots>> [ gc-root-offset ] map ;
: emit-gc-info-bitmaps ( -- scrub-d-count scrub-r-count gc-root-count )
[
gc-maps get {
[ [ scrub-d>> ] map emit-scrub ]
[ [ scrub-r>> ] map emit-scrub ]
[ [ gc-root-offsets ] map emit-gc-roots ]
} cleave
] ?{ } make underlying>> % ;
: emit-base-table ( alist longest -- )
-1 <array> <enum> swap assoc-union! seq>> emit-uints ;
: derived-root-offsets ( gc-map -- offsets )
derived-roots>> [ [ gc-root-offset ] bi@ ] assoc-map ;
: emit-base-tables ( -- count )
gc-maps get [ derived-root-offsets ] map
dup [ keys ] map largest-spill-slot
[ '[ _ emit-base-table ] each ] keep ;
: emit-return-addresses ( -- )
return-addresses get emit-uints ;
: serialize-gc-maps ( -- byte-array )
[
return-addresses get empty? [ 0 emit-uint ] [
emit-gc-info-bitmaps
emit-base-tables
emit-return-addresses
4array emit-uints
return-addresses get length emit-uint
] if
] B{ } make ;
: init-gc-maps ( -- )
V{ } clone return-addresses set
V{ } clone gc-maps set ;
: emit-gc-maps ( -- )
! We want to place the GC maps so that the end is aligned
! on a 16-byte boundary.
serialize-gc-maps [
length compiled-offset +
[ data-alignment get align ] keep -
(align-code)
] [ % ] bi ;