[LVI] Use SmallDenseMap for getValueFromCondition(); NFC

For the common case, we will only insert one value into this map.

Author: nikic

llvm/lib/Analysis/LazyValueInfo.cpp

@@ -1278,11 +1278,11 @@ static ValueLatticeElement getValueFromOverflowCondition(
 
 static ValueLatticeElement
 getValueFromCondition(Value *Val, Value *Cond, bool isTrueDest,
-                      DenseMap<Value*, ValueLatticeElement> &Visited);
+                      SmallDenseMap<Value*, ValueLatticeElement> &Visited);
 
 static ValueLatticeElement
 getValueFromConditionImpl(Value *Val, Value *Cond, bool isTrueDest,
-                          DenseMap<Value*, ValueLatticeElement> &Visited) {
+                          SmallDenseMap<Value*, ValueLatticeElement> &Visited) {
   if (ICmpInst *ICI = dyn_cast<ICmpInst>(Cond))
     return getValueFromICmpCondition(Val, ICI, isTrueDest);
 
@@ -1315,7 +1315,7 @@ getValueFromConditionImpl(Value *Val, Value *Cond, bool isTrueDest,
 
 static ValueLatticeElement
 getValueFromCondition(Value *Val, Value *Cond, bool isTrueDest,
-                      DenseMap<Value*, ValueLatticeElement> &Visited) {
+                      SmallDenseMap<Value*, ValueLatticeElement> &Visited) {
   auto I = Visited.find(Cond);
   if (I != Visited.end())
     return I->second;
@@ -1328,7 +1328,7 @@ getValueFromCondition(Value *Val, Value *Cond, bool isTrueDest,
 ValueLatticeElement getValueFromCondition(Value *Val, Value *Cond,
                                           bool isTrueDest) {
   assert(Cond && "precondition");
-  DenseMap<Value*, ValueLatticeElement> Visited;
+  SmallDenseMap<Value*, ValueLatticeElement> Visited;
   return getValueFromCondition(Val, Cond, isTrueDest, Visited);
 }