diff options
Diffstat (limited to 'lib/Transforms/Scalar/TailRecursionElimination.cpp')
| -rw-r--r-- | lib/Transforms/Scalar/TailRecursionElimination.cpp | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/lib/Transforms/Scalar/TailRecursionElimination.cpp b/lib/Transforms/Scalar/TailRecursionElimination.cpp index 5b6bc04..539cc6f 100644 --- a/lib/Transforms/Scalar/TailRecursionElimination.cpp +++ b/lib/Transforms/Scalar/TailRecursionElimination.cpp @@ -36,7 +36,7 @@ // evaluated each time through the tail recursion. Safely keeping allocas // in the entry block requires analysis to proves that the tail-called // function does not read or write the stack object. -// 2. Tail recursion is only performed if the call immediately preceeds the +// 2. Tail recursion is only performed if the call immediately precedes the // return instruction. It's possible that there could be a jump between // the call and the return. // 3. There can be intervening operations between the call and the return that @@ -433,7 +433,7 @@ bool TailCallElim::EliminateRecursiveTailCall(CallInst *CI, ReturnInst *Ret, if (CanMoveAboveCall(BBI, CI)) continue; // If we can't move the instruction above the call, it might be because it - // is an associative and commutative operation that could be tranformed + // is an associative and commutative operation that could be transformed // using accumulator recursion elimination. Check to see if this is the // case, and if so, remember the initial accumulator value for later. if ((AccumulatorRecursionEliminationInitVal = @@ -496,7 +496,7 @@ bool TailCallElim::EliminateRecursiveTailCall(CallInst *CI, ReturnInst *Ret, Instruction *InsertPos = OldEntry->begin(); for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I) { - PHINode *PN = PHINode::Create(I->getType(), + PHINode *PN = PHINode::Create(I->getType(), 2, I->getName() + ".tr", InsertPos); I->replaceAllUsesWith(PN); // Everyone use the PHI node now! PN->addIncoming(I, NewEntry); @@ -527,8 +527,10 @@ bool TailCallElim::EliminateRecursiveTailCall(CallInst *CI, ReturnInst *Ret, if (AccumulatorRecursionEliminationInitVal) { Instruction *AccRecInstr = AccumulatorRecursionInstr; // Start by inserting a new PHI node for the accumulator. + pred_iterator PB = pred_begin(OldEntry), PE = pred_end(OldEntry); PHINode *AccPN = PHINode::Create(AccumulatorRecursionEliminationInitVal->getType(), + std::distance(PB, PE) + 1, "accumulator.tr", OldEntry->begin()); // Loop over all of the predecessors of the tail recursion block. For the @@ -537,8 +539,7 @@ bool TailCallElim::EliminateRecursiveTailCall(CallInst *CI, ReturnInst *Ret, // other tail recursions eliminated) the accumulator is not modified. // Because we haven't added the branch in the current block to OldEntry yet, // it will not show up as a predecessor. - for (pred_iterator PI = pred_begin(OldEntry), PE = pred_end(OldEntry); - PI != PE; ++PI) { + for (pred_iterator PI = PB; PI != PE; ++PI) { BasicBlock *P = *PI; if (P == &F->getEntryBlock()) AccPN->addIncoming(AccumulatorRecursionEliminationInitVal, P); @@ -572,7 +573,9 @@ bool TailCallElim::EliminateRecursiveTailCall(CallInst *CI, ReturnInst *Ret, // Now that all of the PHI nodes are in place, remove the call and // ret instructions, replacing them with an unconditional branch. - BranchInst::Create(OldEntry, Ret); + BranchInst *NewBI = BranchInst::Create(OldEntry, Ret); + NewBI->setDebugLoc(CI->getDebugLoc()); + BB->getInstList().erase(Ret); // Remove return. BB->getInstList().erase(CI); // Remove call. ++NumEliminated; |
