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- Use of load's chain result should be redirected to load's chain operand. 

If it reads the chain result of the call, then the use, callseq_start,
  and call would form a cycle!
- Don't forget handle node replacement!
- There could also be a TokenFactor between the load and the callseq_start.

llvm-svn: 28420
This commit is contained in:
Evan Cheng 2006-05-20 09:21:39 +00:00
parent 0643f902be
commit 401049ce33
1 changed files with 13 additions and 3 deletions
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16
llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
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@ -840,13 +840,18 @@ void X86DAGToDAGISel::Select(SDOperand &Result, SDOperand N) {
case X86ISD::TAILCALL: {
// Handle indirect call which folds a load here. This never matches by
// the TableGen generated code since the load's chain result is read by
// the callseq_start node.
// the callseq_start node or by a TokenFactor which feeds into the
// callseq_start.
SDOperand N1 = Node->getOperand(1);
if (N1.getOpcode() == ISD::LOAD && N1.hasOneUse() &&
!CodeGenMap.count(N1.getValue(0))) {
SDOperand Chain = Node->getOperand(0);
SDNode *CallStart = FindCallStartFromCall(Chain.Val);
if (!CallStart || CallStart->getOperand(0).Val != N1.Val)
if (!CallStart) break;
SDNode *CSOp0 = CallStart->getOperand(0).Val;
if (! (CSOp0 == N1.Val ||
(CSOp0->getOpcode() == ISD::TokenFactor &&
N1.Val->isOperand(CSOp0))))
break;
SDOperand Base, Scale, Index, Disp;
if (SelectAddr(N1.getOperand(1), Base, Scale, Index, Disp)) {
@ -872,8 +877,13 @@ void X86DAGToDAGISel::Select(SDOperand &Result, SDOperand N) {
SelectionDAG::InsertISelMapEntry(CodeGenMap, N.Val, 0, Chain.Val,
Chain.ResNo);
SelectionDAG::InsertISelMapEntry(CodeGenMap, N1.Val, 1, ResNode, 0);
SelectionDAG::InsertISelMapEntry(CodeGenMap, N.Val, 1, ResNode, 1);
// CALLSEQ_START needs a chain! It can't be ResNode, that would cause
// a cycle. It should be the chain of the load.
Select(Chain, N1.getOperand(0));
SelectionDAG::InsertISelMapEntry(CodeGenMap, N1.Val, 1, Chain.Val,
Chain.ResNo);
AddHandleReplacement(N1.Val, 1, Chain.Val, Chain.ResNo);
Result = SDOperand(ResNode, 0);
#ifndef NDEBUG