/*

* Copyright (c) Facebook, Inc. and its affiliates.

*

* This source code is licensed under the MIT license found in the

* LICENSE file in the root directory of this source tree.

*/

#include "llvh/Support/GenericDomTree.h"

#include "llvh/Support/GenericDomTreeConstruction.h"

#include "hermes/IR/CFG.h"

using namespace hermes;

template class llvh::DominatorTreeBase<BasicBlock, false>;

template class llvh::DomTreeNodeBase<BasicBlock>;

DominanceInfo::DominanceInfo(Function *F) : DominatorTreeBase() {

assert(F->begin() != F->end() && "Function is empty!");

recalculate(*F);

}

bool DominanceInfo::properlyDominates(

const Instruction *A,

const Instruction *B) const {

const BasicBlock *ABB = A->getParent();

const BasicBlock *BBB = B->getParent();

if (ABB != BBB)

return properlyDominates(ABB, BBB);

// Otherwise, they're in the same block, and we just need to check

// whether B comes after A.

auto ItA = A->getIterator();

auto ItB = B->getIterator();

auto E = ABB->begin();

while (ItB != E) {

--ItB;

if (ItA == ItB)

return true;

}

return false;

}