else
NV = V1;
+ if (ExitCondition->getPredicate() == ICmpInst::ICMP_SGT
+ || ExitCondition->getPredicate() == ICmpInst::ICMP_UGT
+ || ExitCondition->getPredicate() == ICmpInst::ICMP_SGE
+ || ExitCondition->getPredicate() == ICmpInst::ICMP_UGE) {
+ ExitCondition->swapOperands();
+ if (ExitValueNum)
+ ExitValueNum = 0;
+ else
+ ExitValueNum = 1;
+ }
+
+ Value *NUB = NULL;
+ Value *NLB = NULL;
+ Value *UB = ExitCondition->getOperand(ExitValueNum);
+ const Type *Ty = NV->getType();
+ bool Sign = ExitCondition->isSignedPredicate();
+ BasicBlock *Preheader = L->getLoopPreheader();
+ Instruction *PHTerminator = Preheader->getTerminator();
+
+ assert (NV && "Unexpected value");
+
switch (CI->getPredicate()) {
case ICmpInst::ICMP_ULE:
case ICmpInst::ICMP_SLE:
// for (i = LB; i < NUB ; ++i)
// LOOP_BODY
//
-
-
-
+ if (ExitCondition->getPredicate() == ICmpInst::ICMP_SLT
+ || ExitCondition->getPredicate() == ICmpInst::ICMP_ULT) {
+ Value *A = BinaryOperator::createAdd(NV, ConstantInt::get(Ty, 1, Sign),
+ "lsplit.add", PHTerminator);
+ Value *C = new ICmpInst(Sign ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
+ A, UB,"lsplit,c", PHTerminator);
+ NUB = new SelectInst (C, A, UB, "lsplit.nub", PHTerminator);
+ }
+
// for (i = LB; i <= UB; ++i)
// if (i <= NV && ...)
// LOOP_BODY
// for (i = LB; i <= NUB ; ++i)
// LOOP_BODY
//
+ else if (ExitCondition->getPredicate() == ICmpInst::ICMP_SLE
+ || ExitCondition->getPredicate() == ICmpInst::ICMP_ULE) {
+ Value *C = new ICmpInst(Sign ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
+ NV, UB, "lsplit.c", PHTerminator);
+ NUB = new SelectInst (C, NV, UB, "lsplit.nub", PHTerminator);
+ }
break;
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_SLT:
// for (i = LB; i < NUB ; ++i)
// LOOP_BODY
//
-
-
+ if (ExitCondition->getPredicate() == ICmpInst::ICMP_SLT
+ || ExitCondition->getPredicate() == ICmpInst::ICMP_ULT) {
+ Value *C = new ICmpInst(Sign ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
+ NV, UB, "lsplit.c", PHTerminator);
+ NUB = new SelectInst (C, NV, UB, "lsplit.nub", PHTerminator);
+ }
// for (i = LB; i <= UB; ++i)
// if (i < NV && ...)
// for (i = LB; i <= NUB ; ++i)
// LOOP_BODY
//
+ else if (ExitCondition->getPredicate() == ICmpInst::ICMP_SLE
+ || ExitCondition->getPredicate() == ICmpInst::ICMP_ULE) {
+ Value *S = BinaryOperator::createSub(NV, ConstantInt::get(Ty, 1, Sign),
+ "lsplit.add", PHTerminator);
+ Value *C = new ICmpInst(Sign ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
+ S, UB, "lsplit.c", PHTerminator);
+ NUB = new SelectInst (C, S, UB, "lsplit.nub", PHTerminator);
+ }
break;
case ICmpInst::ICMP_UGE:
case ICmpInst::ICMP_SGE:
// for (i = NLB; i (< or <=) UB ; ++i)
// LOOP_BODY
//
+ {
+ Value *C = new ICmpInst(Sign ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
+ NV, StartValue, "lsplit.c", PHTerminator);
+ NLB = new SelectInst (C, StartValue, NV, "lsplit.nlb", PHTerminator);
+ }
break;
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_SGT:
// for (i = NLB; i (< or <=) UB ; ++i)
// LOOP_BODY
//
+ {
+ Value *A = BinaryOperator::createAdd(NV, ConstantInt::get(Ty, 1, Sign),
+ "lsplit.add", PHTerminator);
+ Value *C = new ICmpInst(Sign ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
+ A, StartValue, "lsplit.c", PHTerminator);
+ NLB = new SelectInst (C, StartValue, A, "lsplit.nlb", PHTerminator);
+ }
break;
default:
assert ( 0 && "Unexpected split condition predicate");
}
+
+ if (NLB) {
+ unsigned i = IndVar->getBasicBlockIndex(Preheader);
+ IndVar->setIncomingValue(i, NLB);
+ }
+
+ if (NUB) {
+ ExitCondition->setOperand(ExitValueNum, NUB);
+ }
}
/// updateLoopIterationSpace - Current loop body is covered by an AND
/// instruction whose operands compares induction variables with loop
/// updating appropriate start and end values for induction variable.
bool LoopIndexSplit::updateLoopIterationSpace(SplitInfo &SD) {
BasicBlock *Header = L->getHeader();
+ BasicBlock *ExitingBlock = ExitCondition->getParent();
+ BasicBlock *SplitCondBlock = SD.SplitCondition->getParent();
+
ICmpInst *Op0 = cast<ICmpInst>(SD.SplitCondition->getOperand(0));
ICmpInst *Op1 = cast<ICmpInst>(SD.SplitCondition->getOperand(1));
// loop may not be eliminated.
if (!safeExitingBlock(SD, ExitCondition->getParent()))
return false;
-
+
+ // Verify that loop exiting block has only two predecessor, where one predecessor
+ // is split condition block. The other predecessor will become exiting block's
+ // dominator after CFG is updated. TODO : Handle CFG's where exiting block has
+ // more then two predecessors. This requires extra work in updating dominator
+ // information.
+ BasicBlock *ExitingBBPred = NULL;
+ for (pred_iterator PI = pred_begin(ExitingBlock), PE = pred_end(ExitingBlock);
+ PI != PE; ++PI) {
+ BasicBlock *BB = *PI;
+ if (SplitCondBlock == BB)
+ continue;
+ if (ExitingBBPred)
+ return false;
+ else
+ ExitingBBPred = BB;
+ }
+
+ // Update loop bounds to absorb Op0 check.
updateLoopBounds(Op0);
+ // Update loop bounds to absorb Op1 check.
updateLoopBounds(Op1);
+
// Update CFG
- return false;
+
+ // Unconditionally connect split block to its remaining successor.
+ BranchInst *SplitTerminator =
+ cast<BranchInst>(SplitCondBlock->getTerminator());
+ BasicBlock *Succ0 = SplitTerminator->getSuccessor(0);
+ BasicBlock *Succ1 = SplitTerminator->getSuccessor(1);
+ if (Succ0 == ExitCondition->getParent())
+ SplitTerminator->setUnconditionalDest(Succ1);
+ else
+ SplitTerminator->setUnconditionalDest(Succ0);
+
+ // Remove split condition.
+ SD.SplitCondition->eraseFromParent();
+ if (Op0->use_begin() == Op0->use_end())
+ Op0->eraseFromParent();
+ if (Op1->use_begin() == Op1->use_end())
+ Op1->eraseFromParent();
+
+ BranchInst *ExitInsn =
+ dyn_cast<BranchInst>(ExitingBlock->getTerminator());
+ assert (ExitInsn && "Unable to find suitable loop exit branch");
+ BasicBlock *ExitBlock = ExitInsn->getSuccessor(1);
+ if (L->contains(ExitBlock))
+ ExitBlock = ExitInsn->getSuccessor(0);
+
+ // Update domiantor info. Now, ExitingBlock has only one predecessor,
+ // ExitingBBPred, and it is ExitingBlock's immediate domiantor.
+ DT->changeImmediateDominator(ExitingBlock, ExitingBBPred);
+
+ // If ExitingBlock is a member of loop BB's DF list then replace it with
+ // loop header and exit block.
+ for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
+ I != E; ++I) {
+ BasicBlock *BB = *I;
+ if (BB == Header || BB == ExitingBlock)
+ continue;
+ DominanceFrontier::iterator BBDF = DF->find(BB);
+ DominanceFrontier::DomSetType::iterator DomSetI = BBDF->second.begin();
+ DominanceFrontier::DomSetType::iterator DomSetE = BBDF->second.end();
+ while (DomSetI != DomSetE) {
+ DominanceFrontier::DomSetType::iterator CurrentItr = DomSetI;
+ ++DomSetI;
+ BasicBlock *DFBB = *CurrentItr;
+ if (DFBB == ExitingBlock) {
+ BBDF->second.erase(DFBB);
+ BBDF->second.insert(Header);
+ if (Header != ExitingBlock)
+ BBDF->second.insert(ExitBlock);
+ }
+ }
+ }
+
+ return return;
}
projects / oota-llvm.git / blobdiff