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fixes #1103; fixes #1297

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This commit is contained in:
Araq 2014-07-08 02:02:58 +02:00
commit f16449ec22
5 changed files with 137 additions and 31 deletions
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82
compiler/vmgen.nim
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@ -19,7 +19,13 @@
# .. code-block:: nimrod
# let s = a & b # no matter what, create fresh node
# s = a & b # no matter what, keep the node
#
#
# Also *stores* into non-temporary memory need to perform deep copies:
# a.b = x.y
# We used to generate opcAsgn for the *load* of 'x.y' but this is clearly
# wrong! We need to produce opcAsgn (the copy) for the *store*. This also
# solves the opcLdConst vs opcAsgnConst issue. Of course whether we need
# this copy depends on the involved types.
import
unsigned, strutils, ast, astalgo, types, msgs, renderer, vmdef,
@ -531,12 +537,12 @@ proc genAsgnPatch(c: PCtx; le: PNode, value: TRegister) =
c.freeTemp(dest)
of nkDerefExpr, nkHiddenDeref:
let dest = c.genx(le.sons[0], {gfAddrOf})
c.gABC(le, opcWrDeref, dest, value)
c.gABC(le, opcWrDeref, dest, 0, value)
c.freeTemp(dest)
of nkSym:
if le.sym.isGlobal:
let dest = c.genx(le, {gfAddrOf})
c.gABC(le, opcWrDeref, dest, value)
c.gABC(le, opcWrDeref, dest, 0, value)
c.freeTemp(dest)
else:
discard
@ -1097,6 +1103,25 @@ proc checkCanEval(c: PCtx; n: PNode) =
not s.isOwnedBy(c.prc.sym) and s.owner != c.module:
cannotEval(n)
proc isTemp(c: PCtx; dest: TDest): bool =
result = dest >= 0 and c.prc.slots[dest].kind >= slotTempUnknown
template needsAdditionalCopy(n): expr =
not c.isTemp(dest) and not fitsRegister(n.typ)
proc preventFalseAlias(c: PCtx; n: PNode; opc: TOpcode;
dest, idx, value: TRegister) =
# opcLdObj et al really means "load address". We sometimes have to create a
# copy in order to not introduce false aliasing:
# mylocal = a.b # needs a copy of the data!
if needsAdditionalCopy(n):
var cc = c.getTemp(n.typ)
c.gABC(n, whichAsgnOpc(n), cc, value)
c.gABC(n, opc, dest, idx, cc)
c.freeTemp(cc)
else:
c.gABC(n, opc, dest, idx, value)
proc genAsgn(c: PCtx; le, ri: PNode; requiresCopy: bool) =
case le.kind
of nkBracketExpr:
@ -1105,9 +1130,9 @@ proc genAsgn(c: PCtx; le, ri: PNode; requiresCopy: bool) =
let tmp = c.genx(ri)
if le.sons[0].typ.skipTypes(abstractVarRange-{tyTypeDesc}).kind in {
tyString, tyCString}:
c.gABC(le, opcWrStrIdx, dest, idx, tmp)
c.preventFalseAlias(le, opcWrStrIdx, dest, idx, tmp)
else:
c.gABC(le, opcWrArr, dest, idx, tmp)
c.preventFalseAlias(le, opcWrArr, dest, idx, tmp)
c.freeTemp(tmp)
of nkDotExpr, nkCheckedFieldExpr:
# XXX field checks here
@ -1115,12 +1140,12 @@ proc genAsgn(c: PCtx; le, ri: PNode; requiresCopy: bool) =
let dest = c.genx(left.sons[0], {gfAddrOf})
let idx = genField(left.sons[1])
let tmp = c.genx(ri)
c.gABC(left, opcWrObj, dest, idx, tmp)
c.preventFalseAlias(left, opcWrObj, dest, idx, tmp)
c.freeTemp(tmp)
of nkDerefExpr, nkHiddenDeref:
let dest = c.genx(le.sons[0], {gfAddrOf})
let tmp = c.genx(ri)
c.gABC(le, opcWrDeref, dest, tmp)
c.preventFalseAlias(le, opcWrDeref, dest, 0, tmp)
c.freeTemp(tmp)
of nkSym:
let s = le.sym
@ -1129,24 +1154,32 @@ proc genAsgn(c: PCtx; le, ri: PNode; requiresCopy: bool) =
withTemp(tmp, le.typ):
c.gen(le, tmp, {gfAddrOf})
let val = c.genx(ri)
c.gABC(le, opcWrDeref, tmp, val)
c.preventFalseAlias(le, opcWrDeref, tmp, 0, val)
c.freeTemp(val)
else:
if s.kind == skForVar: c.setSlot s
internalAssert s.position > 0 or (s.position == 0 and
s.kind in {skParam,skResult})
var dest: TRegister = s.position + ord(s.kind == skParam)
gen(c, ri, dest)
if needsAdditionalCopy(le) and s.kind in {skResult, skVar, skParam}:
var cc = c.getTemp(le.typ)
gen(c, ri, cc)
c.gABC(le, whichAsgnOpc(le), dest, cc)
c.freeTemp(cc)
else:
gen(c, ri, dest)
else:
let dest = c.genx(le, {gfAddrOf})
genAsgn(c, dest, ri, requiresCopy)
proc genLit(c: PCtx; n: PNode; dest: var TDest) =
var opc = opcLdConst
# opcLdConst is now always valid. We produce the necessary copy in the
# assignments now:
#var opc = opcLdConst
if dest < 0: dest = c.getTemp(n.typ)
elif c.prc.slots[dest].kind == slotFixedVar: opc = opcAsgnConst
#elif c.prc.slots[dest].kind == slotFixedVar: opc = opcAsgnConst
let lit = genLiteral(c, n)
c.gABx(n, opc, dest, lit)
c.gABx(n, opcLdConst, dest, lit)
proc genTypeLit(c: PCtx; t: PType; dest: var TDest) =
var n = newNode(nkType)
@ -1175,7 +1208,7 @@ proc genGlobalInit(c: PCtx; n: PNode; s: PSym) =
let dest = c.getTemp(s.typ)
c.gABx(n, opcLdGlobal, dest, s.position)
let tmp = c.genx(s.ast)
c.gABC(n, opcWrDeref, dest, tmp)
c.preventFalseAlias(n, opcWrDeref, dest, 0, tmp)
c.freeTemp(dest)
c.freeTemp(tmp)
@ -1332,7 +1365,7 @@ proc genVarSection(c: PCtx; n: PNode) =
if a.sons[2].kind != nkEmpty:
let tmp = c.genx(a.sons[0], {gfAddrOf})
let val = c.genx(a.sons[2])
c.gABC(a, opcWrDeref, tmp, val)
c.preventFalseAlias(a, opcWrDeref, tmp, 0, val)
c.freeTemp(val)
c.freeTemp(tmp)
else:
@ -1342,7 +1375,14 @@ proc genVarSection(c: PCtx; n: PNode) =
else:
if not fitsRegister(s.typ):
c.gABx(a, ldNullOpcode(s.typ), s.position, c.genType(s.typ))
gen(c, a.sons[2], s.position.TRegister)
let le = a.sons[0]
if not fitsRegister(le.typ) and s.kind in {skResult, skVar, skParam}:
var cc = c.getTemp(le.typ)
gen(c, a.sons[2], cc)
c.gABC(le, whichAsgnOpc(le), s.position.TRegister, cc)
c.freeTemp(cc)
else:
gen(c, a.sons[2], s.position.TRegister)
else:
# assign to a.sons[0]; happens for closures
if a.sons[2].kind == nkEmpty:
@ -1370,7 +1410,7 @@ proc genArrayConstr(c: PCtx, n: PNode, dest: var TDest) =
c.gABx(n, opcLdNullReg, tmp, c.genType(intType))
for x in n:
let a = c.genx(x)
c.gABC(n, whichAsgnOpc(x, opcWrArr), dest, tmp, a)
c.preventFalseAlias(n, whichAsgnOpc(x, opcWrArr), dest, tmp, a)
c.gABI(n, opcAddImmInt, tmp, tmp, 1)
c.freeTemp(a)
c.freeTemp(tmp)
@ -1402,7 +1442,8 @@ proc genObjConstr(c: PCtx, n: PNode, dest: var TDest) =
if it.kind == nkExprColonExpr and it.sons[0].kind == nkSym:
let idx = genField(it.sons[0])
let tmp = c.genx(it.sons[1])
c.gABC(it, whichAsgnOpc(it.sons[1], opcWrObj), dest, idx, tmp)
c.preventFalseAlias(it.sons[1], whichAsgnOpc(it.sons[1], opcWrObj),
dest, idx, tmp)
c.freeTemp(tmp)
else:
internalError(n.info, "invalid object constructor")
@ -1416,11 +1457,12 @@ proc genTupleConstr(c: PCtx, n: PNode, dest: var TDest) =
if it.kind == nkExprColonExpr:
let idx = genField(it.sons[0])
let tmp = c.genx(it.sons[1])
c.gABC(it, whichAsgnOpc(it.sons[1], opcWrObj), dest, idx, tmp)
c.preventFalseAlias(it.sons[1], whichAsgnOpc(it.sons[1], opcWrObj),
dest, idx, tmp)
c.freeTemp(tmp)
else:
let tmp = c.genx(it)
c.gABC(it, whichAsgnOpc(it, opcWrObj), dest, i.TRegister, tmp)
c.preventFalseAlias(it, whichAsgnOpc(it, opcWrObj), dest, i.TRegister, tmp)
c.freeTemp(tmp)
proc genProc*(c: PCtx; s: PSym): int
@ -1658,7 +1700,7 @@ proc genProc(c: PCtx; s: PSym): int =
c.gABC(body, opcEof, eofInstr.regA)
c.optimizeJumps(result)
s.offset = c.prc.maxSlots
#if s.name.s == "find":
#if s.name.s == "get_data":
# echo renderTree(body)
# c.echoCode(result)
c.prc = oldPrc