Support nested CALLSEQ_BEGIN/END; necessary for ARM byval support. <rdar://problem/7662569>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129761 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Stuart Hastings 2011-04-19 16:16:58 +00:00
parent 1a0390253b
commit fc52163a45

View File

@ -61,15 +61,13 @@ class SelectionDAGLegalize {
// Libcall insertion helpers.
/// LastCALLSEQ_END - This keeps track of the CALLSEQ_END node that has been
/// LastCALLSEQ - This keeps track of the CALLSEQ_END node that has been
/// legalized. We use this to ensure that calls are properly serialized
/// against each other, including inserted libcalls.
SDValue LastCALLSEQ_END;
SmallVector<SDValue, 8> LastCALLSEQ;
/// IsLegalizingCall - This member is used *only* for purposes of providing
/// helpful assertions that a libcall isn't created while another call is
/// being legalized (which could lead to non-serialized call sequences).
bool IsLegalizingCall;
// Track CALLSEQ_BEGIN/CALLSEQ_END nesting.
int depthCALLSEQ;
enum LegalizeAction {
Legal, // The target natively supports this operation.
@ -184,6 +182,18 @@ private:
void ExpandNode(SDNode *Node, SmallVectorImpl<SDValue> &Results);
void PromoteNode(SDNode *Node, SmallVectorImpl<SDValue> &Results);
SDValue getLastCALLSEQ() { return LastCALLSEQ.back(); /*[depthCALLSEQ];*/ }
void setLastCALLSEQ(const SDValue s) { LastCALLSEQ.back() /*[depthCALLSEQ]*/ = s; }
void pushLastCALLSEQ(SDValue s) {
depthCALLSEQ++;
LastCALLSEQ.push_back(s);
}
void popLastCALLSEQ() {
LastCALLSEQ.pop_back();
depthCALLSEQ--;
assert(depthCALLSEQ >= 0 && "excess pop of LastCALLSEQ");
}
};
}
@ -229,8 +239,8 @@ SelectionDAGLegalize::SelectionDAGLegalize(SelectionDAG &dag,
}
void SelectionDAGLegalize::LegalizeDAG() {
LastCALLSEQ_END = DAG.getEntryNode();
IsLegalizingCall = false;
depthCALLSEQ = 0;
pushLastCALLSEQ(DAG.getEntryNode());
// The legalize process is inherently a bottom-up recursive process (users
// legalize their uses before themselves). Given infinite stack space, we
@ -258,14 +268,15 @@ void SelectionDAGLegalize::LegalizeDAG() {
/// FindCallEndFromCallStart - Given a chained node that is part of a call
/// sequence, find the CALLSEQ_END node that terminates the call sequence.
static SDNode *FindCallEndFromCallStart(SDNode *Node, int depth = 0) {
// Nested CALLSEQ_START/END constructs aren't yet legal,
// but we can DTRT and handle them correctly here.
int next_depth = depth;
if (Node->getOpcode() == ISD::CALLSEQ_START)
depth++;
else if (Node->getOpcode() == ISD::CALLSEQ_END) {
depth--;
if (depth == 0)
next_depth = depth + 1;
if (Node->getOpcode() == ISD::CALLSEQ_END) {
assert(depth > 0 && "negative depth!");
if (depth == 1)
return Node;
else
next_depth = depth - 1;
}
if (Node->use_empty())
return 0; // No CallSeqEnd
@ -296,7 +307,7 @@ static SDNode *FindCallEndFromCallStart(SDNode *Node, int depth = 0) {
SDNode *User = *UI;
for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i)
if (User->getOperand(i) == TheChain)
if (SDNode *Result = FindCallEndFromCallStart(User, depth))
if (SDNode *Result = FindCallEndFromCallStart(User, next_depth))
return Result;
}
return 0;
@ -941,11 +952,12 @@ SDValue SelectionDAGLegalize::LegalizeOp(SDValue Op) {
case ISD::BR_JT:
case ISD::BR_CC:
case ISD::BRCOND:
// Branches tweak the chain to include LastCALLSEQ_END
assert(depthCALLSEQ == 1 && "branch inside CALLSEQ_BEGIN/END?");
// Branches tweak the chain to include LastCALLSEQ
Ops[0] = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Ops[0],
LastCALLSEQ_END);
getLastCALLSEQ());
Ops[0] = LegalizeOp(Ops[0]);
LastCALLSEQ_END = DAG.getEntryNode();
setLastCALLSEQ(DAG.getEntryNode());
break;
case ISD::SHL:
case ISD::SRL:
@ -1034,6 +1046,7 @@ SDValue SelectionDAGLegalize::LegalizeOp(SDValue Op) {
break;
case ISD::CALLSEQ_START: {
SDNode *CallEnd = FindCallEndFromCallStart(Node);
assert(CallEnd && "didn't find CALLSEQ_END!");
// Recursively Legalize all of the inputs of the call end that do not lead
// to this call start. This ensures that any libcalls that need be inserted
@ -1050,9 +1063,9 @@ SDValue SelectionDAGLegalize::LegalizeOp(SDValue Op) {
// Merge in the last call to ensure that this call starts after the last
// call ended.
if (LastCALLSEQ_END.getOpcode() != ISD::EntryToken) {
if (getLastCALLSEQ().getOpcode() != ISD::EntryToken) {
Tmp1 = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
Tmp1, LastCALLSEQ_END);
Tmp1, getLastCALLSEQ());
Tmp1 = LegalizeOp(Tmp1);
}
@ -1073,25 +1086,28 @@ SDValue SelectionDAGLegalize::LegalizeOp(SDValue Op) {
// sequence have been legalized, legalize the call itself. During this
// process, no libcalls can/will be inserted, guaranteeing that no calls
// can overlap.
assert(!IsLegalizingCall && "Inconsistent sequentialization of calls!");
// Note that we are selecting this call!
LastCALLSEQ_END = SDValue(CallEnd, 0);
IsLegalizingCall = true;
setLastCALLSEQ(SDValue(CallEnd, 0));
// Legalize the call, starting from the CALLSEQ_END.
LegalizeOp(LastCALLSEQ_END);
assert(!IsLegalizingCall && "CALLSEQ_END should have cleared this!");
LegalizeOp(getLastCALLSEQ());
return Result;
}
case ISD::CALLSEQ_END:
// If the CALLSEQ_START node hasn't been legalized first, legalize it. This
// will cause this node to be legalized as well as handling libcalls right.
if (LastCALLSEQ_END.getNode() != Node) {
LegalizeOp(SDValue(FindCallStartFromCallEnd(Node), 0));
DenseMap<SDValue, SDValue>::iterator I = LegalizedNodes.find(Op);
assert(I != LegalizedNodes.end() &&
"Legalizing the call start should have legalized this node!");
return I->second;
{
SDNode *myCALLSEQ_BEGIN = FindCallStartFromCallEnd(Node);
// If the CALLSEQ_START node hasn't been legalized first, legalize it. This
// will cause this node to be legalized as well as handling libcalls right.
if (getLastCALLSEQ().getNode() != Node) {
LegalizeOp(SDValue(myCALLSEQ_BEGIN, 0));
DenseMap<SDValue, SDValue>::iterator I = LegalizedNodes.find(Op);
assert(I != LegalizedNodes.end() &&
"Legalizing the call start should have legalized this node!");
return I->second;
}
pushLastCALLSEQ(SDValue(myCALLSEQ_BEGIN, 0));
}
// Otherwise, the call start has been legalized and everything is going
@ -1119,9 +1135,8 @@ SDValue SelectionDAGLegalize::LegalizeOp(SDValue Op) {
Result.getResNo());
}
}
assert(IsLegalizingCall && "Call sequence imbalance between start/end?");
// This finishes up call legalization.
IsLegalizingCall = false;
popLastCALLSEQ();
// If the CALLSEQ_END node has a flag, remember that we legalized it.
AddLegalizedOperand(SDValue(Node, 0), Result.getValue(0));
@ -2007,7 +2022,6 @@ SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
// and leave the Hi part unset.
SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
bool isSigned) {
assert(!IsLegalizingCall && "Cannot overlap legalization of calls!");
// The input chain to this libcall is the entry node of the function.
// Legalizing the call will automatically add the previous call to the
// dependence.
@ -2043,7 +2057,7 @@ SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
return DAG.getRoot();
// Legalize the call sequence, starting with the chain. This will advance
// the LastCALLSEQ_END to the legalized version of the CALLSEQ_END node that
// the LastCALLSEQ to the legalized version of the CALLSEQ_END node that
// was added by LowerCallTo (guaranteeing proper serialization of calls).
LegalizeOp(CallInfo.second);
return CallInfo.first;
@ -2055,7 +2069,6 @@ std::pair<SDValue, SDValue>
SelectionDAGLegalize::ExpandChainLibCall(RTLIB::Libcall LC,
SDNode *Node,
bool isSigned) {
assert(!IsLegalizingCall && "Cannot overlap legalization of calls!");
SDValue InChain = Node->getOperand(0);
TargetLowering::ArgListTy Args;
@ -2081,7 +2094,7 @@ SelectionDAGLegalize::ExpandChainLibCall(RTLIB::Libcall LC,
Callee, Args, DAG, Node->getDebugLoc());
// Legalize the call sequence, starting with the chain. This will advance
// the LastCALLSEQ_END to the legalized version of the CALLSEQ_END node that
// the LastCALLSEQ to the legalized version of the CALLSEQ_END node that
// was added by LowerCallTo (guaranteeing proper serialization of calls).
LegalizeOp(CallInfo.second);
return CallInfo;
@ -2217,12 +2230,12 @@ SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
/*isReturnValueUsed=*/true, Callee, Args, DAG, dl);
// Legalize the call sequence, starting with the chain. This will advance
// the LastCALLSEQ_END to the legalized version of the CALLSEQ_END node that
// the LastCALLSEQ to the legalized version of the CALLSEQ_END node that
// was added by LowerCallTo (guaranteeing proper serialization of calls).
LegalizeOp(CallInfo.second);
// Remainder is loaded back from the stack frame.
SDValue Rem = DAG.getLoad(RetVT, dl, LastCALLSEQ_END, FIPtr,
SDValue Rem = DAG.getLoad(RetVT, dl, getLastCALLSEQ(), FIPtr,
MachinePointerInfo(), false, false, 0);
Results.push_back(CallInfo.first);
Results.push_back(Rem);
@ -3533,7 +3546,8 @@ void SelectionDAGLegalize::ExpandNode(SDNode *Node,
LegalizeSetCCCondCode(TLI.getSetCCResultType(Tmp2.getValueType()),
Tmp2, Tmp3, Tmp4, dl);
LastCALLSEQ_END = DAG.getEntryNode();
assert(depthCALLSEQ == 1 && "branch inside CALLSEQ_BEGIN/END?");
setLastCALLSEQ(DAG.getEntryNode());
assert(!Tmp3.getNode() && "Can't legalize BR_CC with legal condition!");
Tmp3 = DAG.getConstant(0, Tmp2.getValueType());