diff options
Diffstat (limited to 'compiler/injectdestructors.nim')
| -rw-r--r-- | compiler/injectdestructors.nim | 62 |
1 files changed, 42 insertions, 20 deletions
diff --git a/compiler/injectdestructors.nim b/compiler/injectdestructors.nim index 606e46568..846dcdf5d 100644 --- a/compiler/injectdestructors.nim +++ b/compiler/injectdestructors.nim @@ -82,7 +82,7 @@ proc aliasesCached(cache: var AliasCache, obj, field: PNode): AliasKind = cache[key] = aliases(obj, field) cache[key] -proc collectLastReads(cfg: ControlFlowGraph; cache: var AliasCache, alreadySeen: var HashSet[PNode], lastReads, potLastReads: var IntSet; pc: var int, until: int) = +proc collectLastReads(cfg: ControlFlowGraph; cache: var AliasCache, lastReads, potLastReads: var IntSet; pc: var int, until: int) = template aliasesCached(obj, field: PNode): untyped = aliasesCached(cache, obj, field) while pc < until: @@ -100,15 +100,6 @@ proc collectLastReads(cfg: ControlFlowGraph; cache: var AliasCache, alreadySeen: cfg[r].n.comment = '\n' & $pc potLastReads.excl r - var alreadySeenThisNode = false - for s in alreadySeen: - if cfg[pc].n.aliases(s) != no or s.aliases(cfg[pc].n) != no: - alreadySeenThisNode = true; break - if alreadySeenThisNode: cfg[pc].n.flags.excl nfFirstWrite - else: cfg[pc].n.flags.incl nfFirstWrite - - alreadySeen.incl cfg[pc].n - inc pc of use: let potLastReadsCopy = potLastReads @@ -119,25 +110,19 @@ proc collectLastReads(cfg: ControlFlowGraph; cache: var AliasCache, alreadySeen: potLastReads.incl pc - alreadySeen.incl cfg[pc].n - inc pc of goto: pc += cfg[pc].dest of fork: - # every branch must lead to the last read of the location: var variantA = pc + 1 var variantB = pc + cfg[pc].dest var potLastReadsA, potLastReadsB = potLastReads var lastReadsA, lastReadsB: IntSet - var alreadySeenA, alreadySeenB = alreadySeen while variantA != variantB and max(variantA, variantB) < cfg.len and min(variantA, variantB) < until: if variantA < variantB: - collectLastReads(cfg, cache, alreadySeenA, lastReadsA, potLastReadsA, variantA, min(variantB, until)) + collectLastReads(cfg, cache, lastReadsA, potLastReadsA, variantA, min(variantB, until)) else: - collectLastReads(cfg, cache, alreadySeenB, lastReadsB, potLastReadsB, variantB, min(variantA, until)) - - alreadySeen.incl alreadySeenA + alreadySeenB + collectLastReads(cfg, cache, lastReadsB, potLastReadsB, variantB, min(variantA, until)) # Add those last reads that were turned into last reads on both branches lastReads.incl lastReadsA * lastReadsB @@ -157,6 +142,40 @@ proc collectLastReads(cfg: ControlFlowGraph; cache: var AliasCache, alreadySeen: pc = min(variantA, variantB) +proc collectFirstWrites(cfg: ControlFlowGraph; alreadySeen: var HashSet[PNode]; pc: var int, until: int) = + while pc < until: + case cfg[pc].kind + of def: + var alreadySeenThisNode = false + for s in alreadySeen: + if cfg[pc].n.aliases(s) != no or s.aliases(cfg[pc].n) != no: + alreadySeenThisNode = true; break + if alreadySeenThisNode: cfg[pc].n.flags.excl nfFirstWrite + else: cfg[pc].n.flags.incl nfFirstWrite + + alreadySeen.incl cfg[pc].n + + inc pc + of use: + alreadySeen.incl cfg[pc].n + + inc pc + of goto: + pc += cfg[pc].dest + of fork: + var variantA = pc + 1 + var variantB = pc + cfg[pc].dest + var alreadySeenA, alreadySeenB = alreadySeen + while variantA != variantB and max(variantA, variantB) < cfg.len and min(variantA, variantB) < until: + if variantA < variantB: + collectFirstWrites(cfg, alreadySeenA, variantA, min(variantB, until)) + else: + collectFirstWrites(cfg, alreadySeenB, variantB, min(variantA, until)) + + alreadySeen.incl alreadySeenA + alreadySeenB + + pc = min(variantA, variantB) + proc isLastRead(n: PNode; c: var Con): bool = let m = dfa.skipConvDfa(n) (m.kind == nkSym and sfSingleUsedTemp in m.sym.flags) or nfLastRead in m.flags @@ -1086,10 +1105,9 @@ proc injectDestructorCalls*(g: ModuleGraph; idgen: IdGenerator; owner: PSym; n: block: var cache = initTable[(PNode, PNode), AliasKind]() - var alreadySeen: HashSet[PNode] var lastReads, potLastReads: IntSet var pc = 0 - collectLastReads(c.g, cache, alreadySeen, lastReads, potLastReads, pc, c.g.len) + collectLastReads(c.g, cache, lastReads, potLastReads, pc, c.g.len) lastReads.incl potLastReads var lastReadTable: Table[PNode, seq[int]] for position, node in c.g: @@ -1102,6 +1120,10 @@ proc injectDestructorCalls*(g: ModuleGraph; idgen: IdGenerator; owner: PSym; n: if allPositionsLastRead: node.flags.incl nfLastRead + var alreadySeen: HashSet[PNode] + pc = 0 + collectFirstWrites(c.g, alreadySeen, pc, c.g.len) + var scope: Scope let body = p(n, c, scope, normal) |