void preserveCanonicalLoopForm(LPPassManager &LPM);
private:
+ LoopInfo *LI;
Loop *L;
BasicBlock *OrigHeader;
BasicBlock *OrigPreHeader;
Pass *llvm::createLoopRotatePass() { return new LoopRotate(); }
+/// Initialize local data
+void LoopRotate::initialize() {
+ L = NULL;
+ OrigHeader = NULL;
+ OrigPreHeader = NULL;
+ NewHeader = NULL;
+ Exit = NULL;
+}
+
/// Rotate Loop L as many times as possible. Return true if
/// the loop is rotated at least once.
bool LoopRotate::runOnLoop(Loop *Lp, LPPassManager &LPM) {
+ LI = &getAnalysis<LoopInfo>();
- bool RotatedOneLoop = false;
initialize();
LPM_Ptr = &LPM;
// One loop can be rotated multiple times.
+ bool MadeChange = false;
while (rotateLoop(Lp,LPM)) {
- RotatedOneLoop = true;
+ MadeChange = true;
initialize();
}
- return RotatedOneLoop;
+ return MadeChange;
}
/// Rotate loop LP. Return true if the loop is rotated.
// With the operands remapped, see if the instruction constant folds or is
// otherwise simplifyable. This commonly occurs because the entry from PHI
// nodes allows icmps and other instructions to fold.
- if (Value *V = SimplifyInstruction(C)) {
+ Value *V = SimplifyInstruction(C);
+ if (V && LI->replacementPreservesLCSSAForm(C, V)) {
// If so, then delete the temporary instruction and stick the folded value
// in the map.
delete C;
return true;
}
-/// Initialize local data
-void LoopRotate::initialize() {
- L = NULL;
- OrigHeader = NULL;
- OrigPreHeader = NULL;
- NewHeader = NULL;
- Exit = NULL;
-}
/// After loop rotation, loop pre-header has multiple sucessors.
/// Insert one forwarding basic block to ensure that loop pre-header