From ec2f42fd40d37eabaa67a22946f0ac25414e2c12 Mon Sep 17 00:00:00 2001 From: Slava Pestov Date: Sat, 25 Sep 2010 14:36:58 -0700 Subject: [PATCH 1/3] compiler.cfg.liveness: merge in compiler.cfg.liveness.ssa and simplify the code, since we don't compute live sets before SSA construction anymore --- .../linear-scan/assignment/assignment.factor | 1 - .../cfg/liveness/liveness-tests.factor | 68 +++++++++++++-- basis/compiler/cfg/liveness/liveness.factor | 82 ++++++++++++++++--- .../cfg/liveness/ssa/ssa-tests.factor | 61 -------------- basis/compiler/cfg/liveness/ssa/ssa.factor | 63 -------------- .../cfg/ssa/destruction/destruction.factor | 10 +-- .../interference/interference-tests.factor | 4 +- .../live-ranges/live-ranges.factor | 2 +- 8 files changed, 139 insertions(+), 152 deletions(-) delete mode 100644 basis/compiler/cfg/liveness/ssa/ssa-tests.factor delete mode 100644 basis/compiler/cfg/liveness/ssa/ssa.factor diff --git a/basis/compiler/cfg/linear-scan/assignment/assignment.factor b/basis/compiler/cfg/linear-scan/assignment/assignment.factor index 365d4e2f21..9a66307a93 100644 --- a/basis/compiler/cfg/linear-scan/assignment/assignment.factor +++ b/basis/compiler/cfg/linear-scan/assignment/assignment.factor @@ -6,7 +6,6 @@ cpu.architecture layouts compiler.cfg compiler.cfg.def-use compiler.cfg.liveness -compiler.cfg.liveness.ssa compiler.cfg.registers compiler.cfg.instructions compiler.cfg.linearization diff --git a/basis/compiler/cfg/liveness/liveness-tests.factor b/basis/compiler/cfg/liveness/liveness-tests.factor index 7099d3a06e..a6bd82183a 100644 --- a/basis/compiler/cfg/liveness/liveness-tests.factor +++ b/basis/compiler/cfg/liveness/liveness-tests.factor @@ -1,19 +1,15 @@ -USING: compiler.cfg.liveness compiler.cfg.liveness.ssa +USING: compiler.cfg.liveness compiler.cfg.debugger compiler.cfg.instructions compiler.cfg.predecessors compiler.cfg.registers compiler.cfg cpu.architecture accessors namespaces sequences kernel tools.test vectors alien math compiler.cfg.comparisons -cpu.x86.assembler.operands ; +cpu.x86.assembler.operands assocs ; IN: compiler.cfg.liveness.tests : test-liveness ( -- ) cfg new 1 get >>entry compute-live-sets ; -: test-ssa-liveness ( -- ) - cfg new 1 get >>entry - compute-ssa-live-sets ; - ! Sanity check... V{ @@ -148,9 +144,65 @@ V{ 7 8 edge 8 9 edge -[ ] [ test-ssa-liveness ] unit-test +[ ] [ test-liveness ] unit-test [ H{ { 28 28 } { 29 29 } { 30 30 } { 31 31 } } ] [ 5 get live-out ] unit-test [ H{ { 28 28 } { 29 29 } { 30 30 } } ] [ 6 get live-in ] unit-test [ H{ { 28 28 } { 29 29 } { 31 31 } } ] [ 7 get live-in ] unit-test -[ H{ { 30 30 } } ] [ 6 get 8 get edge-live-in ] unit-test \ No newline at end of file +[ H{ { 30 30 } } ] [ 6 get 8 get edge-live-in ] unit-test + +V{ + T{ ##prologue } + T{ ##branch } +} 0 test-bb + +V{ + T{ ##branch } +} 1 test-bb + +V{ + T{ ##load-integer f 0 0 } + T{ ##branch } +} 2 test-bb + +V{ + T{ ##load-integer f 1 1 } + T{ ##branch } +} 3 test-bb + +V{ + T{ ##phi f 2 H{ { 2 0 } { 3 1 } } } + T{ ##branch } +} 4 test-bb + +V{ + T{ ##branch } +} 5 test-bb + +V{ + T{ ##replace f 2 D 0 } + T{ ##branch } +} 6 test-bb + +V{ + T{ ##epilogue } + T{ ##return } +} 7 test-bb + +0 1 edge +1 { 2 3 } edges +2 4 edge +3 4 edge +4 { 5 6 } edges +5 6 edge +6 7 edge + +[ ] [ cfg new 0 get >>entry dup cfg set compute-live-sets ] unit-test + +[ t ] [ 0 get live-in assoc-empty? ] unit-test + +[ H{ { 2 2 } } ] [ 4 get live-out ] unit-test + +[ H{ { 0 0 } } ] [ 2 get 4 get edge-live-in ] unit-test + +[ H{ { 1 1 } } ] [ 3 get 4 get edge-live-in ] unit-test \ No newline at end of file diff --git a/basis/compiler/cfg/liveness/liveness.factor b/basis/compiler/cfg/liveness/liveness.factor index cbf4105392..25d78a8d8f 100644 --- a/basis/compiler/cfg/liveness/liveness.factor +++ b/basis/compiler/cfg/liveness/liveness.factor @@ -1,17 +1,31 @@ ! Copyright (C) 2009, 2010 Slava Pestov. ! See http://factorcode.org/license.txt for BSD license. -USING: kernel accessors assocs namespaces sequences sets -compiler.cfg.def-use compiler.cfg.dataflow-analysis +USING: kernel accessors assocs fry deques dlists namespaces +sequences sets compiler.cfg compiler.cfg.def-use compiler.cfg.instructions compiler.cfg.registers -cpu.architecture ; +compiler.cfg.utilities compiler.cfg.predecessors +compiler.cfg.rpo cpu.architecture ; +FROM: namespaces => set ; IN: compiler.cfg.liveness ! See http://en.wikipedia.org/wiki/Liveness_analysis -! Do not run after SSA construction; compiler.cfg.liveness.ssa -! should be used instead. The transfer-liveness word is used -! by SSA liveness too, so it handles ##phi instructions. -BACKWARD-ANALYSIS: live +SYMBOL: live-ins + +: live-in ( bb -- set ) + live-ins get at ; + +SYMBOL: live-outs + +: live-out ( bb -- set ) + live-outs get at ; + +! Assoc mapping basic blocks to sequences of sets of vregs; each +! sequence is in correspondence with a predecessor +SYMBOL: edge-live-ins + +: edge-live-in ( predecessor basic-block -- set ) + edge-live-ins get at at ; GENERIC: visit-insn ( live-set insn -- live-set ) @@ -23,6 +37,11 @@ GENERIC: visit-insn ( live-set insn -- live-set ) M: vreg-insn visit-insn [ kill-defs ] [ gen-uses ] bi ; +! Our liveness analysis annotates call sites with GC maps +! indicating the spill slots in the stack frame that contain +! tagged pointers, and thus have to be visited if a GC occurs +! inside the call. + : fill-gc-map ( live-set insn -- live-set ) representations get [ gc-map>> over keys @@ -44,8 +63,49 @@ M: insn visit-insn drop ; : local-live-in ( instructions -- live-set ) [ H{ } ] dip transfer-liveness keys ; -M: live-analysis transfer-set - drop instructions>> transfer-liveness ; +SYMBOL: work-list -M: live-analysis join-sets - 2drop assoc-combine ; +: add-to-work-list ( basic-blocks -- ) + work-list get '[ _ push-front ] each ; + +: compute-live-in ( basic-block -- live-in ) + [ live-out ] keep instructions>> transfer-liveness ; + +: compute-edge-live-in ( basic-block -- edge-live-in ) + H{ } clone [ + '[ inputs>> [ swap _ conjoin-at ] assoc-each ] each-phi + ] keep ; + +: update-live-in ( basic-block -- changed? ) + [ [ compute-live-in ] keep live-ins get maybe-set-at ] + [ [ compute-edge-live-in ] keep edge-live-ins get maybe-set-at ] + bi or ; + +: compute-live-out ( basic-block -- live-out ) + [ successors>> [ live-in ] map ] + [ dup successors>> [ edge-live-in ] with map ] bi + append assoc-combine ; + +: update-live-out ( basic-block -- changed? ) + [ compute-live-out ] keep + live-outs get maybe-set-at ; + +: liveness-step ( basic-block -- ) + dup update-live-out [ + dup update-live-in + [ predecessors>> add-to-work-list ] [ drop ] if + ] [ drop ] if ; + +: compute-live-sets ( cfg -- ) + needs-predecessors + + work-list set + H{ } clone live-ins set + H{ } clone edge-live-ins set + H{ } clone live-outs set + post-order add-to-work-list + work-list get [ liveness-step ] slurp-deque ; + +: live-in? ( vreg bb -- ? ) live-in key? ; + +: live-out? ( vreg bb -- ? ) live-out key? ; diff --git a/basis/compiler/cfg/liveness/ssa/ssa-tests.factor b/basis/compiler/cfg/liveness/ssa/ssa-tests.factor deleted file mode 100644 index 5413c65b32..0000000000 --- a/basis/compiler/cfg/liveness/ssa/ssa-tests.factor +++ /dev/null @@ -1,61 +0,0 @@ -USING: accessors compiler.cfg compiler.cfg.debugger -compiler.cfg.instructions compiler.cfg.liveness.ssa -compiler.cfg.liveness arrays sequences assocs -compiler.cfg.registers kernel namespaces tools.test ; -IN: compiler.cfg.liveness.ssa.tests - -V{ - T{ ##prologue } - T{ ##branch } -} 0 test-bb - -V{ - T{ ##branch } -} 1 test-bb - -V{ - T{ ##load-integer f 0 0 } - T{ ##branch } -} 2 test-bb - -V{ - T{ ##load-integer f 1 1 } - T{ ##branch } -} 3 test-bb - -V{ - T{ ##phi f 2 H{ { 2 0 } { 3 1 } } } - T{ ##branch } -} 4 test-bb - -V{ - T{ ##branch } -} 5 test-bb - -V{ - T{ ##replace f 2 D 0 } - T{ ##branch } -} 6 test-bb - -V{ - T{ ##epilogue } - T{ ##return } -} 7 test-bb - -0 1 edge -1 { 2 3 } edges -2 4 edge -3 4 edge -4 { 5 6 } edges -5 6 edge -6 7 edge - -[ ] [ cfg new 0 get >>entry dup cfg set compute-ssa-live-sets ] unit-test - -[ t ] [ 0 get live-in assoc-empty? ] unit-test - -[ H{ { 2 2 } } ] [ 4 get live-out ] unit-test - -[ H{ { 0 0 } } ] [ 2 get 4 get edge-live-in ] unit-test - -[ H{ { 1 1 } } ] [ 3 get 4 get edge-live-in ] unit-test diff --git a/basis/compiler/cfg/liveness/ssa/ssa.factor b/basis/compiler/cfg/liveness/ssa/ssa.factor deleted file mode 100644 index 84428514aa..0000000000 --- a/basis/compiler/cfg/liveness/ssa/ssa.factor +++ /dev/null @@ -1,63 +0,0 @@ -! Copyright (C) 2009, 2010 Slava Pestov. -! See http://factorcode.org/license.txt for BSD license. -USING: kernel namespaces deques accessors sets sequences assocs fry -hashtables dlists compiler.cfg.def-use compiler.cfg.instructions -compiler.cfg.rpo compiler.cfg.liveness compiler.cfg.utilities -compiler.cfg.predecessors ; -FROM: namespaces => set ; -IN: compiler.cfg.liveness.ssa - -! TODO: merge with compiler.cfg.liveness - -! Assoc mapping basic blocks to sequences of sets of vregs; each sequence -! is in correspondence with a predecessor -SYMBOL: edge-live-ins - -: edge-live-in ( predecessor basic-block -- set ) edge-live-ins get at at ; - -SYMBOL: work-list - -: add-to-work-list ( basic-blocks -- ) - work-list get '[ _ push-front ] each ; - -: compute-live-in ( basic-block -- live-in ) - [ live-out ] keep instructions>> transfer-liveness ; - -: compute-edge-live-in ( basic-block -- edge-live-in ) - H{ } clone [ - '[ inputs>> [ swap _ conjoin-at ] assoc-each ] each-phi - ] keep ; - -: update-live-in ( basic-block -- changed? ) - [ [ compute-live-in ] keep live-ins get maybe-set-at ] - [ [ compute-edge-live-in ] keep edge-live-ins get maybe-set-at ] - bi or ; - -: compute-live-out ( basic-block -- live-out ) - [ successors>> [ live-in ] map ] - [ dup successors>> [ edge-live-in ] with map ] bi - append assoc-combine ; - -: update-live-out ( basic-block -- changed? ) - [ compute-live-out ] keep - live-outs get maybe-set-at ; - -: liveness-step ( basic-block -- ) - dup update-live-out [ - dup update-live-in - [ predecessors>> add-to-work-list ] [ drop ] if - ] [ drop ] if ; - -: compute-ssa-live-sets ( cfg -- ) - needs-predecessors - - work-list set - H{ } clone live-ins set - H{ } clone edge-live-ins set - H{ } clone live-outs set - post-order add-to-work-list - work-list get [ liveness-step ] slurp-deque ; - -: live-in? ( vreg bb -- ? ) live-in key? ; - -: live-out? ( vreg bb -- ? ) live-out key? ; diff --git a/basis/compiler/cfg/ssa/destruction/destruction.factor b/basis/compiler/cfg/ssa/destruction/destruction.factor index 197093e5ae..981ce42363 100644 --- a/basis/compiler/cfg/ssa/destruction/destruction.factor +++ b/basis/compiler/cfg/ssa/destruction/destruction.factor @@ -9,7 +9,7 @@ compiler.cfg.def-use compiler.cfg.registers compiler.cfg.dominance compiler.cfg.instructions -compiler.cfg.liveness.ssa +compiler.cfg.liveness compiler.cfg.ssa.cssa compiler.cfg.ssa.interference compiler.cfg.ssa.interference.live-ranges @@ -28,9 +28,9 @@ IN: compiler.cfg.ssa.destruction ! 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. +! 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. SYMBOL: leader-map @@ -134,7 +134,7 @@ PRIVATE> dup construct-cssa dup compute-defs dup compute-insns - dup compute-ssa-live-sets + dup compute-live-sets dup compute-live-ranges dup prepare-coalescing process-copies diff --git a/basis/compiler/cfg/ssa/interference/interference-tests.factor b/basis/compiler/cfg/ssa/interference/interference-tests.factor index 36c03bc6af..8648c3ae50 100644 --- a/basis/compiler/cfg/ssa/interference/interference-tests.factor +++ b/basis/compiler/cfg/ssa/interference/interference-tests.factor @@ -1,6 +1,6 @@ USING: accessors compiler.cfg compiler.cfg.debugger compiler.cfg.def-use compiler.cfg.dominance -compiler.cfg.instructions compiler.cfg.liveness.ssa +compiler.cfg.instructions compiler.cfg.liveness compiler.cfg.registers compiler.cfg.predecessors compiler.cfg.comparisons compiler.cfg.ssa.interference compiler.cfg.ssa.interference.private @@ -11,7 +11,7 @@ IN: compiler.cfg.ssa.interference.tests : test-interference ( -- ) cfg new 0 get >>entry - dup compute-ssa-live-sets + dup compute-live-sets dup compute-defs dup compute-insns compute-live-ranges ; diff --git a/basis/compiler/cfg/ssa/interference/live-ranges/live-ranges.factor b/basis/compiler/cfg/ssa/interference/live-ranges/live-ranges.factor index ffbbf8739f..c3b3d4cf0b 100644 --- a/basis/compiler/cfg/ssa/interference/live-ranges/live-ranges.factor +++ b/basis/compiler/cfg/ssa/interference/live-ranges/live-ranges.factor @@ -2,7 +2,7 @@ ! See http://factorcode.org/license.txt for BSD license. USING: accessors assocs fry kernel namespaces sequences math arrays compiler.cfg.def-use compiler.cfg.instructions -compiler.cfg.liveness.ssa compiler.cfg.rpo +compiler.cfg.liveness compiler.cfg.rpo compiler.cfg.dominance compiler.cfg ; IN: compiler.cfg.ssa.interference.live-ranges From 80d7aab40b42e0e95b361c33ea7b3ed15b765f93 Mon Sep 17 00:00:00 2001 From: Slava Pestov Date: Sat, 25 Sep 2010 16:13:17 -0700 Subject: [PATCH 2/3] compiler.cfg.alias-analysis: don't need to do a local live-in calculation anymore --- .../cfg/alias-analysis/alias-analysis.factor | 48 ++++++++----------- 1 file changed, 21 insertions(+), 27 deletions(-) diff --git a/basis/compiler/cfg/alias-analysis/alias-analysis.factor b/basis/compiler/cfg/alias-analysis/alias-analysis.factor index 6fff3f0216..775bf65fe5 100644 --- a/basis/compiler/cfg/alias-analysis/alias-analysis.factor +++ b/basis/compiler/cfg/alias-analysis/alias-analysis.factor @@ -6,7 +6,6 @@ sets classes layouts fry locals cpu.architecture compiler.cfg compiler.cfg.rpo compiler.cfg.def-use -compiler.cfg.liveness compiler.cfg.registers compiler.cfg.utilities compiler.cfg.comparisons @@ -79,19 +78,23 @@ SYMBOL: copies ! Map vregs -> alias classes SYMBOL: vregs>acs -ERROR: vreg-ac-not-set vreg ; +! Map alias classes -> sequence of vregs +SYMBOL: acs>vregs + +! Alias class for objects which are loaded from the data stack +! or other object slots. We pessimistically assume that they +! can all alias each other. +SYMBOL: heap-ac + +: ac>vregs ( ac -- vregs ) + acs>vregs get [ drop V{ } clone ] cache ; : vreg>ac ( vreg -- ac ) #! Only vregs produced by ##allot, ##peek and ##slot can #! ever be used as valid inputs to ##slot and ##set-slot, #! so we assert this fact by not giving alias classes to #! other vregs. - vregs>acs get ?at [ vreg-ac-not-set ] unless ; - -! Map alias classes -> sequence of vregs -SYMBOL: acs>vregs - -: ac>vregs ( ac -- vregs ) acs>vregs get at ; + vregs>acs get [ heap-ac get [ ac>vregs push ] keep ] cache ; : aliases ( vreg -- vregs ) #! All vregs which may contain the same value as vreg. @@ -120,10 +123,11 @@ SYMBOL: dead-stores : dead-store ( insn# -- ) dead-stores get adjoin ; +ERROR: vreg-not-new vreg ; + :: set-ac ( vreg ac -- ) #! Set alias class of newly-seen vreg. - H{ } clone vreg recent-stores get set-at - H{ } clone vreg live-slots get set-at + vreg vregs>acs get key? [ vreg vreg-not-new ] when ac vreg vregs>acs get set-at vreg ac acs>vregs get push-at ; @@ -132,10 +136,8 @@ SYMBOL: dead-stores #! value. over [ live-slots get at at ] [ 2drop f ] if ; -ERROR: vreg-has-no-slots vreg ; - : load-constant-slot ( value slot# vreg -- ) - live-slots get ?at [ vreg-has-no-slots ] unless set-at ; + live-slots get [ drop H{ } clone ] cache set-at ; : load-slot ( value slot#/f vreg -- ) over [ load-constant-slot ] [ 3drop ] if ; @@ -160,20 +162,16 @@ SYMBOL: ac-counter : next-ac ( -- n ) ac-counter [ dup 1 + ] change ; -! Alias class for objects which are loaded from the data stack -! or other object slots. We pessimistically assume that they -! can all alias each other. -SYMBOL: heap-ac - -: set-heap-ac ( vreg -- ) heap-ac get set-ac ; - : set-new-ac ( vreg -- ) next-ac set-ac ; : kill-constant-set-slot ( slot# vreg -- ) [ live-slots get at delete-at ] with each-alias ; +: recent-stores-of ( vreg -- assoc ) + recent-stores get [ drop H{ } clone ] cache ; + :: record-constant-set-slot ( insn# slot# vreg -- ) - vreg recent-stores get at :> recent-stores + vreg recent-stores-of :> recent-stores slot# recent-stores at [ dead-store ] when* insn# slot# recent-stores set-at ; @@ -226,15 +224,12 @@ M: insn analyze-aliases ; ! inserted yet. dup [ { int-rep tagged-rep } member? - [ set-heap-ac ] [ set-new-ac ] if + [ drop ] [ set-new-ac ] if ] each-def-rep ; M: vreg-insn analyze-aliases def-acs ; -M: ##phi analyze-aliases - dup dst>> set-heap-ac ; - M: ##allocation analyze-aliases #! A freshly allocated object is distinct from any other #! object. @@ -326,9 +321,8 @@ M: insn eliminate-dead-stores drop t ; : alias-analysis-step ( insns -- insns' ) reset-alias-analysis - [ local-live-in [ set-heap-ac ] each ] [ 0 [ [ insn#<< ] [ drop 1 + ] 2bi ] reduce drop ] - [ [ analyze-aliases ] map! [ eliminate-dead-stores ] filter! ] tri ; + [ [ analyze-aliases ] map! [ eliminate-dead-stores ] filter! ] bi ; : alias-analysis ( cfg -- cfg ) init-alias-analysis From 546b81b697e4a73e2716b52f1f4c6518ee17bc12 Mon Sep 17 00:00:00 2001 From: Slava Pestov Date: Sat, 25 Sep 2010 16:31:42 -0700 Subject: [PATCH 3/3] compiler.cfg.scheduling: always run scheduling because heuristic was broken --- basis/compiler/cfg/scheduling/scheduling.factor | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/basis/compiler/cfg/scheduling/scheduling.factor b/basis/compiler/cfg/scheduling/scheduling.factor index d56b5559ce..cc99050328 100644 --- a/basis/compiler/cfg/scheduling/scheduling.factor +++ b/basis/compiler/cfg/scheduling/scheduling.factor @@ -3,8 +3,7 @@ USING: accessors arrays assocs fry kernel locals make math namespaces sequences sets combinators.short-circuit compiler.cfg.def-use compiler.cfg.dependence -compiler.cfg.instructions compiler.cfg.liveness compiler.cfg.rpo -cpu.architecture ; +compiler.cfg.instructions compiler.cfg.rpo cpu.architecture ; IN: compiler.cfg.scheduling ! Instruction scheduling to reduce register pressure, from: @@ -130,18 +129,7 @@ ERROR: definition-after-usage vregs old-bb new-bb ; ] change-instructions drop ] with-scheduling-check ; -! Really, instruction scheduling should be aware that there are -! multiple types of registers, but this number is just used -! to decide whether to schedule instructions -: num-registers ( -- x ) int-regs machine-registers at length ; - -: might-spill? ( bb -- ? ) - [ live-in assoc-size ] - [ instructions>> [ defs-vregs length ] map-sum ] bi - + num-registers >= ; - : schedule-instructions ( cfg -- cfg' ) dup [ - dup { [ kill-block?>> not ] [ might-spill? ] } 1&& - [ schedule-block ] [ drop ] if + dup kill-block?>> [ drop ] [ schedule-block ] if ] each-basic-block ;