Pass *createReassociatePass() { return new Reassociate(); }
void Reassociate::BuildRankMap(Function &F) {
- unsigned i = 1;
+ unsigned i = 2;
ReversePostOrderTraversal<Function*> RPOT(&F);
for (ReversePostOrderTraversal<Function*>::rpo_iterator I = RPOT.begin(),
E = RPOT.end(); I != E; ++I)
- RankMap[*I] = ++i;
+ RankMap[*I] = ++i << 16;
}
unsigned Reassociate::getRank(Value *V) {
if (isa<Argument>(V)) return 1; // Function argument...
if (Instruction *I = dyn_cast<Instruction>(V)) {
- // If this is an expression, return the MAX(rank(LHS), rank(RHS)) so that we
- // can reassociate expressions for code motion! Since we do not recurse for
- // PHI nodes, we cannot have infinite recursion here, because there cannot
- // be loops in the value graph that do not go through PHI nodes.
+ // If this is an expression, return the 1+MAX(rank(LHS), rank(RHS)) so that
+ // we can reassociate expressions for code motion! Since we do not recurse
+ // for PHI nodes, we cannot have infinite recursion here, because there
+ // cannot be loops in the value graph that do not go through PHI nodes.
//
if (I->getOpcode() == Instruction::PHINode ||
I->getOpcode() == Instruction::Alloca ||
i != e && Rank != MaxRank; ++i)
Rank = std::max(Rank, getRank(I->getOperand(i)));
- return CachedRank = Rank;
+ DEBUG(std::cerr << "Calculated Rank[" << V->getName() << "] = "
+ << Rank+1 << "\n");
+
+ return CachedRank = Rank+1;
}
// Otherwise it's a global or constant, rank 0.
// Since we modified the RHS instruction, make sure that we recheck it.
ReassociateExpr(LHSI);
+ ReassociateExpr(I);
return true;
}
}