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Node selected into address mode cannot be folded.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29374 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2006-07-28 00:49:31 +00:00
parent 2641cad180
commit 2584d93acf
1 changed files with 39 additions and 0 deletions
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39
lib/Target/X86/X86ISelDAGToDAG.cpp
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@ -211,6 +211,21 @@ namespace {
return ReachibilityMatrix[Idx / 8] & (1 << (Idx % 8));
}
/// UnfoldableSet - An boolean array representing nodes which have been
/// folded into addressing modes and therefore should not be folded in
/// another operation.
unsigned char *UnfoldableSet;
inline void setUnfoldable(SDNode *N) {
unsigned Id = N->getNodeId();
UnfoldableSet[Id / 8] |= 1 << (Id % 8);
}
inline bool isUnfoldable(SDNode *N) {
unsigned Id = N->getNodeId();
return UnfoldableSet[Id / 8] & (1 << (Id % 8));
}
#ifndef NDEBUG
unsigned Indent;
#endif
@ -218,6 +233,10 @@ namespace {
}
bool X86DAGToDAGISel::IsFoldableBy(SDNode *N, SDNode *U) {
// Is it already folded by SelectAddr / SelectLEAAddr?
if (isUnfoldable(N))
return false;
// If U use can somehow reach N through another path then U can't fold N or
// it will create a cycle. e.g. In the following diagram, U can reach N
// through X. If N is foled into into U, then X is both a predecessor and
@ -323,6 +342,10 @@ void X86DAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
MachineFunction::iterator FirstMBB = BB;
DAGSize = DAG.AssignNodeIds();
unsigned NumBytes = (DAGSize+7) / 8;
UnfoldableSet = new unsigned char[NumBytes];
memset(UnfoldableSet, 0, NumBytes);
DetermineTopologicalOrdering();
// Codegen the basic block.
@ -339,9 +362,11 @@ void X86DAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
delete[] TopOrder;
delete[] IdToOrder;
delete[] RMRange;
delete[] UnfoldableSet;
ReachibilityMatrix = NULL;
TopOrder = NULL;
IdToOrder = RMRange = NULL;
UnfoldableSet = NULL;
CodeGenMap.clear();
HandleMap.clear();
ReplaceMap.clear();
@ -615,6 +640,13 @@ bool X86DAGToDAGISel::SelectAddr(SDOperand N, SDOperand &Base, SDOperand &Scale,
getAddressOperands(AM, Base, Scale, Index, Disp);
int Id = Base.Val ? Base.Val->getNodeId() : -1;
if (Id != -1)
setUnfoldable(Base.Val);
Id = Index.Val ? Index.Val->getNodeId() : -1;
if (Id != -1)
setUnfoldable(Index.Val);
return true;
}
@ -663,6 +695,13 @@ bool X86DAGToDAGISel::SelectLEAAddr(SDOperand N, SDOperand &Base,
return true;
}
int Id = Base.Val ? Base.Val->getNodeId() : -1;
if (Id != -1)
setUnfoldable(Base.Val);
Id = Index.Val ? Index.Val->getNodeId() : -1;
if (Id != -1)
setUnfoldable(Index.Val);
return false;
}