When looking for a vector representation of a scalar, do a single lookup. Also, cache the result of the broadcast instruction.

No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166191 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nadav Rotem 2012-10-18 17:31:49 +00:00
parent b1f8c139c5
commit bef36ac2a4

View File

@ -63,7 +63,6 @@ namespace {
/// to a given vectorization factor (VF).
class SingleBlockLoopVectorizer {
public:
/// Ctor.
SingleBlockLoopVectorizer(Loop *OrigLoop, ScalarEvolution *Se, LoopInfo *Li,
LPPassManager *Lpm, unsigned VecWidth):
@ -118,6 +117,8 @@ private:
/// broadcast them into a vector.
Value *getVectorValue(Value *V);
typedef DenseMap<Value*, Value*> ValueMap;
/// The original loop.
Loop *Orig;
// Scev analysis to use.
@ -139,7 +140,7 @@ private:
/// The induction variable of the old basic block.
PHINode *OldInduction;
// Maps scalars to widened vectors.
DenseMap<Value*, Value*> WidenMap;
ValueMap WidenMap;
};
/// Perform the vectorization legality check. This class does not look at the
@ -284,8 +285,8 @@ bool SingleBlockLoopVectorizer::isConsecutiveGep(GetElementPtrInst *Gep) {
if (!SE->isLoopInvariant(SE->getSCEV(Gep->getOperand(i)), Orig))
return false;
// The last operand has to be the induction in order to emit
// a wide load/store.
// We can emit wide load/stores only of the last index is the induction
// variable.
const SCEV *Last = SE->getSCEV(LastIndex);
if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(Last)) {
const SCEV *Step = AR->getStepRecurrence(*SE);
@ -300,9 +301,15 @@ bool SingleBlockLoopVectorizer::isConsecutiveGep(GetElementPtrInst *Gep) {
}
Value *SingleBlockLoopVectorizer::getVectorValue(Value *V) {
if (WidenMap.count(V))
return WidenMap[V];
return getBroadcastInstrs(V);
// If we saved a vectorized copy of V, use it.
ValueMap::iterator it = WidenMap.find(V);
if (it != WidenMap.end())
return it->second;
// Broadcast V and save the value for future uses.
Value *B = getBroadcastInstrs(V);
WidenMap[V] = B;
return B;
}
void SingleBlockLoopVectorizer::scalarizeInstruction(Instruction *Instr) {