diff options
Diffstat (limited to 'compiler/injectdestructors.nim')
| -rw-r--r-- | compiler/injectdestructors.nim | 70 |
1 files changed, 38 insertions, 32 deletions
diff --git a/compiler/injectdestructors.nim b/compiler/injectdestructors.nim index 44409c760..5785df6d6 100644 --- a/compiler/injectdestructors.nim +++ b/compiler/injectdestructors.nim @@ -65,9 +65,9 @@ template dbg(body) = proc p(n: PNode; c: var Con; mode: ProcessMode): PNode proc moveOrCopy(dest, ri: PNode; c: var Con): PNode -proc isLastRead(location: PNode; c: var Con; pc, comesFrom: int): int = +proc isLastRead(location: PNode; c: var Con; pc, until: int): int = var pc = pc - while pc < c.g.len: + while pc < c.g.len and pc < until: case c.g[pc].kind of def: if defInstrTargets(c.g[pc], location): @@ -83,15 +83,17 @@ proc isLastRead(location: PNode; c: var Con; pc, comesFrom: int): int = pc = pc + c.g[pc].dest of fork: # every branch must lead to the last read of the location: - let variantA = isLastRead(location, c, pc+1, pc) - if variantA < 0: return -1 - var variantB = isLastRead(location, c, pc + c.g[pc].dest, pc) - if variantB < 0: return -1 + var variantA = pc + 1 + var variantB = pc + c.g[pc].dest + while variantA != variantB: + if min(variantA, variantB) < 0: return -1 + if max(variantA, variantB) >= c.g.len or min(variantA, variantB) >= until: + break + if variantA < variantB: + variantA = isLastRead(location, c, variantA, min(variantB, until)) + else: + variantB = isLastRead(location, c, variantB, min(variantA, until)) pc = min(variantA, variantB) - of InstrKind.join: - let dest = pc + c.g[pc].dest - if dest == comesFrom: return pc + 1 - inc pc return pc proc isLastRead(n: PNode; c: var Con): bool = @@ -114,12 +116,12 @@ proc isLastRead(n: PNode; c: var Con): bool = # ensure that we don't find another 'use X' instruction. if instr+1 >= c.g.len: return true - result = isLastRead(n, c, instr+1, -1) >= 0 + result = isLastRead(n, c, instr+1, int.high) >= 0 dbg: echo "ugh ", c.otherRead.isNil, " ", result -proc isFirstWrite(location: PNode; c: var Con; pc, comesFrom: int; instr: int): int = +proc isFirstWrite(location: PNode; c: var Con; pc, until: int): int = var pc = pc - while pc < instr: + while pc < until: case c.g[pc].kind of def: if defInstrTargets(c.g[pc], location): @@ -134,15 +136,17 @@ proc isFirstWrite(location: PNode; c: var Con; pc, comesFrom: int; instr: int): pc = pc + c.g[pc].dest of fork: # every branch must not contain a def/use of our location: - let variantA = isFirstWrite(location, c, pc+1, pc, instr) - if variantA < 0: return -1 - var variantB = isFirstWrite(location, c, pc + c.g[pc].dest, pc, instr + c.g[pc].dest) - if variantB < 0: return -1 + var variantA = pc + 1 + var variantB = pc + c.g[pc].dest + while variantA != variantB: + if min(variantA, variantB) < 0: return -1 + if max(variantA, variantB) > until: + break + if variantA < variantB: + variantA = isFirstWrite(location, c, variantA, min(variantB, until)) + else: + variantB = isFirstWrite(location, c, variantB, min(variantA, until)) pc = min(variantA, variantB) - of InstrKind.join: - let dest = pc + c.g[pc].dest - if dest == comesFrom: return pc + 1 - inc pc return pc proc isFirstWrite(n: PNode; c: var Con): bool = @@ -161,10 +165,10 @@ proc isFirstWrite(n: PNode; c: var Con): bool = # ensure that we don't find another 'def/use X' instruction. if instr == 0: return true - result = isFirstWrite(n, c, 0, -1, instr) >= 0 + result = isFirstWrite(n, c, 0, instr) >= 0 proc initialized(code: ControlFlowGraph; pc: int, - init, uninit: var IntSet; comesFrom: int): int = + init, uninit: var IntSet; until: int): int = ## Computes the set of definitely initialized variables across all code paths ## as an IntSet of IDs. var pc = pc @@ -173,20 +177,22 @@ proc initialized(code: ControlFlowGraph; pc: int, of goto: pc = pc + code[pc].dest of fork: - let target = pc + code[pc].dest var initA = initIntSet() var initB = initIntSet() - let pcA = initialized(code, pc+1, initA, uninit, pc) - discard initialized(code, target, initB, uninit, pc) + var variantA = pc + 1 + var variantB = pc + code[pc].dest + while variantA != variantB: + if max(variantA, variantB) > until: + break + if variantA < variantB: + variantA = initialized(code, variantA, initA, uninit, min(variantB, until)) + else: + variantB = initialized(code, variantB, initB, uninit, min(variantA, until)) + pc = min(variantA, variantB) # we add vars if they are in both branches: for v in initA: if v in initB: init.incl v - pc = pcA+1 - of InstrKind.join: - let target = pc + code[pc].dest - if comesFrom == target: return pc - inc pc of use: let v = code[pc].n.sym if v.kind != skParam and v.id notin init: @@ -1040,7 +1046,7 @@ proc computeUninit(c: var Con) = c.uninitComputed = true c.uninit = initIntSet() var init = initIntSet() - discard initialized(c.g, pc = 0, init, c.uninit, comesFrom = -1) + discard initialized(c.g, pc = 0, init, c.uninit, int.high) proc injectDefaultCalls(n: PNode, c: var Con) = case n.kind |