///
bool Loop::isLoopInvariant(Value *V) const {
if (Instruction *I = dyn_cast<Instruction>(V))
- return isLoopInvariant(I);
+ return !contains(I);
return true; // All non-instructions are loop invariant
}
-/// isLoopInvariant - Return true if the specified instruction is
-/// loop-invariant.
-///
-bool Loop::isLoopInvariant(Instruction *I) const {
- return !contains(I);
+/// hasLoopInvariantOperands - Return true if all the operands of the
+/// specified instruction are loop invariant.
+bool Loop::hasLoopInvariantOperands(Instruction *I) const {
+ for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
+ if (!isLoopInvariant(I->getOperand(i)))
+ return false;
+
+ return true;
}
/// makeLoopInvariant - If the given value is an instruciton inside of the
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
if (!makeLoopInvariant(I->getOperand(i), Changed, InsertPt))
return false;
+
// Hoist.
I->moveBefore(InsertPt);
Changed = true;
return 0;
}
-/// getCanonicalInductionVariableIncrement - Return the LLVM value that holds
-/// the canonical induction variable value for the "next" iteration of the
-/// loop. This always succeeds if getCanonicalInductionVariable succeeds.
-///
-Instruction *Loop::getCanonicalInductionVariableIncrement() const {
- if (PHINode *PN = getCanonicalInductionVariable()) {
- bool P1InLoop = contains(PN->getIncomingBlock(1));
- return cast<Instruction>(PN->getIncomingValue(P1InLoop));
- }
- return 0;
-}
-
/// getTripCount - Return a loop-invariant LLVM value indicating the number of
/// times the loop will be executed. Note that this means that the backedge
/// of the loop executes N-1 times. If the trip-count cannot be determined,
Value *Loop::getTripCount() const {
// Canonical loops will end with a 'cmp ne I, V', where I is the incremented
// canonical induction variable and V is the trip count of the loop.
- Instruction *Inc = getCanonicalInductionVariableIncrement();
- if (Inc == 0) return 0;
- PHINode *IV = cast<PHINode>(Inc->getOperand(0));
+ PHINode *IV = getCanonicalInductionVariable();
+ if (IV == 0 || IV->getNumIncomingValues() != 2) return 0;
- BasicBlock *BackedgeBlock =
- IV->getIncomingBlock(contains(IV->getIncomingBlock(1)));
+ bool P0InLoop = contains(IV->getIncomingBlock(0));
+ Value *Inc = IV->getIncomingValue(!P0InLoop);
+ BasicBlock *BackedgeBlock = IV->getIncomingBlock(!P0InLoop);
if (BranchInst *BI = dyn_cast<BranchInst>(BackedgeBlock->getTerminator()))
if (BI->isConditional()) {