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sink parameters: next steps

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This commit is contained in:
Andreas Rumpf 2018-04-01 17:59:54 +02:00
commit 542618da70
1 changed files with 11 additions and 8 deletions
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19
compiler/destroyer.nim
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@ -299,13 +299,16 @@ proc moveOrCopy(dest, ri: PNode; c: var Con): PNode =
proc passCopyToSink(n: PNode; c: var Con): PNode = proc passCopyToSink(n: PNode; c: var Con): PNode =
result = newNodeIT(nkStmtListExpr, n.info, n.typ) result = newNodeIT(nkStmtListExpr, n.info, n.typ)
let tmp = getTemp(c, n.typ, n.info) let tmp = getTemp(c, n.typ, n.info)
var m = genCopy(n.typ, tmp) if hasDestructor(n.typ):
m.add n var m = genCopy(n.typ, tmp)
result.add m m.add p(n, c)
result.add m
message(n.info, hintPerformance,
"passing '$1' to a sink parameter introduces an implicit copy; " &
"use 'move($1)' to prevent it" % $n)
else:
result.add newTree(nkAsgn, tmp, p(n, c))
result.add tmp result.add tmp
message(n.info, hintPerformance,
"passing '$1' to a sink parameter introduces an implicit copy; " &
"use 'move($1)' to prevent it" % $n)
proc genReset(n: PNode; c: var Con): PNode = proc genReset(n: PNode; c: var Con): PNode =
result = newNodeI(nkCall, n.info) result = newNodeI(nkCall, n.info)
@ -365,7 +368,7 @@ proc p(n: PNode; c: var Con): PNode =
varSection.add itCopy varSection.add itCopy
result.add varSection result.add varSection
of nkCallKinds: of nkCallKinds:
let parameters = n.typ let parameters = n[0].typ
let L = if parameters != nil: parameters.len else: 0 let L = if parameters != nil: parameters.len else: 0
for i in 1 ..< n.len: for i in 1 ..< n.len:
let arg = n[i] let arg = n[i]
@ -376,7 +379,7 @@ proc p(n: PNode; c: var Con): PNode =
let a = copyNode(arg) let a = copyNode(arg)
recurse(arg, a) recurse(arg, a)
n.sons[i] = a n.sons[i] = a
elif arg.kind == nkObjConstr: elif arg.kind in {nkObjConstr, nkCharLit..nkFloat128Lit}:
discard "object construction to sink parameter: nothing to do" discard "object construction to sink parameter: nothing to do"
elif arg.kind == nkSym and isHarmlessVar(arg.sym, c): elif arg.kind == nkSym and isHarmlessVar(arg.sym, c):
# if x is a variable and it its last read we eliminate its # if x is a variable and it its last read we eliminate its