Ignore redundant constraints

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42397 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Daniel Berlin 2007-09-27 15:42:23 +00:00
parent 9a2f93121b
commit c7a12ae24a

View File

@ -134,6 +134,21 @@ namespace {
assert(Offset == 0 || Ty != AddressOf &&
"Offset is illegal on addressof constraints");
}
bool operator==(const Constraint &RHS) const {
return RHS.Type == Type
&& RHS.Dest == Dest
&& RHS.Src == Src
&& RHS.Offset == Offset;
}
bool operator<(const Constraint &RHS) const {
if (RHS.Type != Type)
return RHS.Type < Type;
else if (RHS.Dest != Dest)
return RHS.Dest < Dest;
else if (RHS.Src != Src)
return RHS.Src < Src;
return RHS.Offset < Offset;
}
};
// Node class - This class is used to represent a node in the constraint
@ -1735,6 +1750,7 @@ void Andersens::HUValNum(unsigned NodeIndex) {
/// replaced by their the pointer equivalence class representative.
void Andersens::RewriteConstraints() {
std::vector<Constraint> NewConstraints;
std::set<Constraint> Seen;
PEClass2Node.clear();
PENLEClass2Node.clear();
@ -1768,12 +1784,14 @@ void Andersens::RewriteConstraints() {
// it.
if (C.Src == C.Dest && C.Type == Constraint::Copy)
continue;
C.Src = FindEquivalentNode(RHSNode, RHSLabel);
C.Dest = FindEquivalentNode(FindNode(LHSNode), LHSLabel);
if (C.Src == C.Dest && C.Type == Constraint::Copy)
if (C.Src == C.Dest && C.Type == Constraint::Copy
|| Seen.count(C) != 0)
continue;
Seen.insert(C);
NewConstraints.push_back(C);
}
Constraints.swap(NewConstraints);