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compiler.cfg.dce: now performs three passes over the CFG to fix a phase ordering issue

db4
Slava Pestov 2009-07-02 03:17:19 -05:00
parent 513a600664
commit 3a4916462b
2 changed files with 54 additions and 19 deletions
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12
basis/compiler/cfg/dce/dce-tests.factor
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@ -58,3 +58,15 @@ IN: compiler.cfg.dce.tests
T{ ##allot { dst V int-regs 1 } { temp V int-regs 2 } }
T{ ##replace { src V int-regs 1 } { loc D 0 } }
} test-dce ] unit-test
[ V{
T{ ##allot { dst V int-regs 1 } { temp V int-regs 2 } }
T{ ##replace { src V int-regs 1 } { loc D 0 } }
T{ ##load-immediate { dst V int-regs 3 } { val 8 } }
T{ ##set-slot-imm { obj V int-regs 1 } { src V int-regs 3 } }
} ] [ V{
T{ ##allot { dst V int-regs 1 } { temp V int-regs 2 } }
T{ ##replace { src V int-regs 1 } { loc D 0 } }
T{ ##load-immediate { dst V int-regs 3 } { val 8 } }
T{ ##set-slot-imm { obj V int-regs 1 } { src V int-regs 3 } }
} test-dce ] unit-test

61
basis/compiler/cfg/dce/dce.factor
View File

@ -11,22 +11,48 @@ SYMBOL: liveness-graph
! vregs which participate in side effects and thus are always live
SYMBOL: live-vregs
: live-vreg? ( vreg -- ? )
live-vregs get key? ;
! vregs which are the result of an allocation
SYMBOL: allocations
: allocation? ( vreg -- ? )
allocations get key? ;
: init-dead-code ( -- )
H{ } clone liveness-graph set
H{ } clone live-vregs set
H{ } clone allocations set ;
GENERIC: update-liveness-graph ( insn -- )
GENERIC: build-liveness-graph ( insn -- )
: add-edges ( insn register -- )
[ uses-vregs ] dip liveness-graph get [ union ] change-at ;
M: ##flushable update-liveness-graph
: setter-liveness-graph ( insn vreg -- )
dup allocation? [ add-edges ] [ 2drop ] if ;
M: ##set-slot build-liveness-graph
dup obj>> setter-liveness-graph ;
M: ##set-slot-imm build-liveness-graph
dup obj>> setter-liveness-graph ;
M: ##write-barrier build-liveness-graph
dup src>> setter-liveness-graph ;
M: ##flushable build-liveness-graph
dup dst>> add-edges ;
M: ##allot build-liveness-graph
[ dst>> allocations get conjoin ]
[ call-next-method ] bi ;
M: insn build-liveness-graph drop ;
GENERIC: compute-live-vregs ( insn -- )
: (record-live) ( vregs -- )
[
dup live-vregs get key? [ drop ] [
@ -39,29 +65,25 @@ M: ##flushable update-liveness-graph
: record-live ( insn -- )
uses-vregs (record-live) ;
M: insn update-liveness-graph record-live ;
: setter-live-vregs ( insn vreg -- )
allocation? [ drop ] [ record-live ] if ;
: update-allocation-liveness ( insn vreg -- )
dup allocations get key? [ add-edges ] [ drop record-live ] if ;
M: ##set-slot compute-live-vregs
dup obj>> setter-live-vregs ;
M: ##set-slot update-liveness-graph
dup obj>> update-allocation-liveness ;
M: ##set-slot-imm compute-live-vregs
dup obj>> setter-live-vregs ;
M: ##set-slot-imm update-liveness-graph
dup obj>> update-allocation-liveness ;
M: ##write-barrier compute-live-vregs
dup src>> setter-live-vregs ;
M: ##write-barrier update-liveness-graph
dup src>> update-allocation-liveness ;
M: ##flushable compute-live-vregs drop ;
M: ##allot update-liveness-graph
[ dst>> allocations get conjoin ]
[ call-next-method ] bi ;
M: insn compute-live-vregs
record-live ;
GENERIC: live-insn? ( insn -- ? )
: live-vreg? ( vreg -- ? )
live-vregs get key? ;
M: ##flushable live-insn? dst>> live-vreg? ;
M: ##set-slot live-insn? obj>> live-vreg? ;
@ -74,7 +96,8 @@ M: insn live-insn? drop t ;
: eliminate-dead-code ( cfg -- cfg' )
init-dead-code
[ [ instructions>> [ update-liveness-graph ] each ] each-basic-block ]
dup
[ [ instructions>> [ build-liveness-graph ] each ] each-basic-block ]
[ [ instructions>> [ compute-live-vregs ] each ] each-basic-block ]
[ [ [ [ live-insn? ] filter ] change-instructions drop ] each-basic-block ]
[ ]
tri ;