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'parallel' statement almost working

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This commit is contained in:
Araq 2014-05-22 08:41:50 +02:00
commit 417b9f5a1d
10 changed files with 470 additions and 115 deletions
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89
compiler/semparallel.nim
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@ -9,8 +9,8 @@
## Semantic checking for 'parallel'.
# - codegen needs to support mSlice
# - lowerings must not perform unnecessary copies
# - codegen needs to support mSlice (+)
# - lowerings must not perform unnecessary copies (+)
# - slices should become "nocopy" to openArray (+)
# - need to perform bound checks (+)
#
@ -19,7 +19,7 @@
# - what about 'f(a)'? --> f shouldn't have side effects anyway
# - passed arrays need to be ensured not to alias
# - passed slices need to be ensured to be disjoint (+)
# - output slices need special logic
# - output slices need special logic (+)
import
ast, astalgo, idents, lowerings, magicsys, guards, sempass2, msgs,
@ -94,23 +94,6 @@ proc getSlot(c: var AnalysisCtx; v: PSym): ptr MonotonicVar =
c.locals[L].v = v
return addr(c.locals[L])
proc getRoot(n: PNode): PSym =
## ``getRoot`` takes a *path* ``n``. A path is an lvalue expression
## like ``obj.x[i].y``. The *root* of a path is the symbol that can be
## determined as the owner; ``obj`` in the example.
case n.kind
of nkSym:
if n.sym.kind in {skVar, skResult, skTemp, skLet, skForVar}:
result = n.sym
of nkDotExpr, nkBracketExpr, nkHiddenDeref, nkDerefExpr,
nkObjUpConv, nkObjDownConv, nkCheckedFieldExpr:
result = getRoot(n.sons[0])
of nkHiddenStdConv, nkHiddenSubConv, nkConv:
result = getRoot(n.sons[1])
of nkCallKinds:
if getMagic(n) == mSlice: result = getRoot(n.sons[1])
else: discard
proc gatherArgs(c: var AnalysisCtx; n: PNode) =
for i in 0.. <n.safeLen:
let root = getRoot n[i]
@ -184,8 +167,6 @@ proc overlap(m: TModel; x,y,c,d: PNode) =
of impNo: discard
proc stride(c: AnalysisCtx; n: PNode): BiggestInt =
# note: 0 if it cannot be determined is just right because then
# we analyse 'i..i' and 'i+0 .. i+0' and these are not disjoint!
if isLocal(n):
let s = c.lookupSlot(n.sym)
if s >= 0 and c.locals[s].stride != nil:
@ -193,6 +174,20 @@ proc stride(c: AnalysisCtx; n: PNode): BiggestInt =
else:
for i in 0 .. <n.safeLen: result += stride(c, n.sons[i])
proc subStride(c: AnalysisCtx; n: PNode): PNode =
# substitute with stride:
if isLocal(n):
let s = c.lookupSlot(n.sym)
if s >= 0 and c.locals[s].stride != nil:
result = n +@ c.locals[s].stride.intVal
else:
result = n
elif n.safeLen > 0:
result = shallowCopy(n)
for i in 0 .. <n.len: result.sons[i] = subStride(c, n.sons[i])
else:
result = n
proc checkSlicesAreDisjoint(c: var AnalysisCtx) =
# this is the only thing that we need to perform after we have traversed
# the whole tree so that the strides are available.
@ -200,7 +195,7 @@ proc checkSlicesAreDisjoint(c: var AnalysisCtx) =
addLowerBoundAsFacts(c)
# Every slice used in a loop needs to be disjoint with itself:
for x,a,b,id,inLoop in items(c.slices):
if inLoop: overlap(c.guards, a,b, a+@c.stride(a), b+@c.stride(b))
if inLoop: overlap(c.guards, a,b, c.subStride(a), c.subStride(b))
# Another tricky example is:
# while true:
# spawn f(a[i])
@ -283,23 +278,19 @@ proc analyseCall(c: var AnalysisCtx; n: PNode; op: PSym) =
proc analyseCase(c: var AnalysisCtx; n: PNode) =
analyse(c, n.sons[0])
#let oldState = c.locals.len
let oldFacts = c.guards.len
for i in 1.. <n.len:
let branch = n.sons[i]
#setLen(c.locals, oldState)
setLen(c.guards, oldFacts)
addCaseBranchFacts(c.guards, n, i)
for i in 0 .. <branch.len:
analyse(c, branch.sons[i])
#setLen(c.locals, oldState)
setLen(c.guards, oldFacts)
proc analyseIf(c: var AnalysisCtx; n: PNode) =
analyse(c, n.sons[0].sons[0])
let oldFacts = c.guards.len
addFact(c.guards, n.sons[0].sons[0])
#let oldState = c.locals.len
analyse(c, n.sons[0].sons[1])
for i in 1.. <n.len:
@ -309,10 +300,8 @@ proc analyseIf(c: var AnalysisCtx; n: PNode) =
addFactNeg(c.guards, n.sons[j].sons[0])
if branch.len > 1:
addFact(c.guards, branch.sons[0])
#setLen(c.locals, oldState)
for i in 0 .. <branch.len:
analyse(c, branch.sons[i])
#setLen(c.locals, oldState)
setLen(c.guards, oldFacts)
proc analyse(c: var AnalysisCtx; n: PNode) =
@ -390,17 +379,40 @@ proc transformSlices(n: PNode): PNode =
else:
result = n
proc transformSpawn(owner: PSym; n, barrier: PNode): PNode
proc transformSpawnSons(owner: PSym; n, barrier: PNode): PNode =
result = shallowCopy(n)
for i in 0 .. < n.len:
result.sons[i] = transformSpawn(owner, n.sons[i], barrier)
proc transformSpawn(owner: PSym; n, barrier: PNode): PNode =
if n.kind in nkCallKinds:
if n[0].kind == nkSym:
let op = n[0].sym
if op.magic == mSpawn:
result = transformSlices(n)
return wrapProcForSpawn(owner, result[1], barrier)
case n.kind
of nkVarSection:
result = nil
for it in n:
let b = it.lastSon
if getMagic(b) == mSpawn:
if it.len != 3: localError(it.info, "invalid context for 'spawn'")
let m = transformSlices(b)
if result.isNil:
result = newNodeI(nkStmtList, n.info)
result.add n
result.add wrapProcForSpawn(owner, m[1], b.typ, barrier, it[0])
it.sons[it.len-1] = emptyNode
if result.isNil: result = n
of nkAsgn, nkFastAsgn:
let b = n[1]
if getMagic(b) == mSpawn:
let m = transformSlices(b)
return wrapProcForSpawn(owner, m[1], b.typ, barrier, n[0])
result = transformSpawnSons(owner, n, barrier)
of nkCallKinds:
if getMagic(n) == mSpawn:
result = transformSlices(n)
return wrapProcForSpawn(owner, result[1], n.typ, barrier, nil)
result = transformSpawnSons(owner, n, barrier)
elif n.safeLen > 0:
result = shallowCopy(n)
for i in 0 .. < n.len:
result.sons[i] = transformSpawn(owner, n.sons[i], barrier)
result = transformSpawnSons(owner, n, barrier)
else:
result = n
@ -440,3 +452,4 @@ proc liftParallel*(owner: PSym; n: PNode): PNode =
result.add callCodeGenProc("openBarrier", barrier)
result.add transformSpawn(owner, body, barrier)
result.add callCodeGenProc("closeBarrier", barrier)