// Test whether two basic blocks have equivalent behaviour.
int FunctionComparator::cmpBasicBlocks(const BasicBlock *BBL,
const BasicBlock *BBR) const {
BasicBlock::const_iterator InstL = BBL->begin(), InstLE = BBL->end();
BasicBlock::const_iterator InstR = BBR->begin(), InstRE = BBR->end();
do {
bool needToCmpOperands = true;
if (int Res = cmpOperations(&*InstL, &*InstR, needToCmpOperands))
return Res;
if (needToCmpOperands) {
assert(InstL->getNumOperands() == InstR->getNumOperands());
for (unsigned i = 0, e = InstL->getNumOperands(); i != e; ++i) {
Value *OpL = InstL->getOperand(i);
Value *OpR = InstR->getOperand(i);
if (int Res = cmpValues(OpL, OpR))
return Res;
// cmpValues should ensure this is true.
assert(cmpTypes(OpL->getType(), OpR->getType()) == 0);
}
}
++InstL;
++InstR;
} while (InstL != InstLE && InstR != InstRE);
if (InstL != InstLE && InstR == InstRE)
return 1;
if (InstL == InstLE && InstR != InstRE)
return -1;
return 0;
}
static bool equals(const BasicBlock *BB1, const BasicBlock *BB2,
DenseMap<const Value *, const Value *> &ValueMap,
DenseMap<const Value *, const Value *> &SpeculationMap) {
// Specutively add it anyways. If it's false, we'll notice a difference later, and
// this won't matter.
ValueMap[BB1] = BB2;
BasicBlock::const_iterator FI = BB1->begin(), FE = BB1->end();
BasicBlock::const_iterator GI = BB2->begin(), GE = BB2->end();
do {
if (!FI->isSameOperationAs(const_cast<Instruction *>(&*GI)))
return false;
if (FI->getNumOperands() != GI->getNumOperands())
return false;
if (ValueMap[FI] == GI) {
++FI, ++GI;
continue;
}
if (ValueMap[FI] != NULL)
return false;
for (unsigned i = 0, e = FI->getNumOperands(); i != e; ++i) {
Value *OpF = FI->getOperand(i);
Value *OpG = GI->getOperand(i);
if (ValueMap[OpF] == OpG)
continue;
if (ValueMap[OpF] != NULL)
return false;
assert(OpF->getType() == OpG->getType() &&
"Two of the same operation has operands of different type.");
if (OpF->getValueID() != OpG->getValueID())
return false;
if (isa<PHINode>(FI)) {
if (SpeculationMap[OpF] == NULL)
SpeculationMap[OpF] = OpG;
else if (SpeculationMap[OpF] != OpG)
return false;
continue;
} else if (isa<BasicBlock>(OpF)) {
assert(isa<TerminatorInst>(FI) &&
"BasicBlock referenced by non-Terminator non-PHI");
// This call changes the ValueMap, hence we can't use
// Value *& = ValueMap[...]
if (!equals(cast<BasicBlock>(OpF), cast<BasicBlock>(OpG), ValueMap,
SpeculationMap))
return false;
} else {
if (!compare(OpF, OpG))
return false;
}
ValueMap[OpF] = OpG;
}
ValueMap[FI] = GI;
++FI, ++GI;
} while (FI != FE && GI != GE);
return FI == FE && GI == GE;
}
static bool equals(const BasicBlock *BB1, const BasicBlock *BB2,
DenseMap<const Value *, const Value *> &ValueMap,
DenseMap<const Value *, const Value *> &SpeculationMap) {
// Speculatively add it anyways. If it's false, we'll notice a difference
// later, and this won't matter.
ValueMap[BB1] = BB2;
BasicBlock::const_iterator FI = BB1->begin(), FE = BB1->end();
BasicBlock::const_iterator GI = BB2->begin(), GE = BB2->end();
do {
if (isa<BitCastInst>(FI)) {
++FI;
continue;
}
if (isa<BitCastInst>(GI)) {
++GI;
continue;
}
if (!isEquivalentOperation(FI, GI))
return false;
if (isa<GetElementPtrInst>(FI)) {
const GetElementPtrInst *GEPF = cast<GetElementPtrInst>(FI);
const GetElementPtrInst *GEPG = cast<GetElementPtrInst>(GI);
if (GEPF->hasAllZeroIndices() && GEPG->hasAllZeroIndices()) {
// It's effectively a bitcast.
++FI, ++GI;
continue;
}
// TODO: we only really care about the elements before the index
if (FI->getOperand(0)->getType() != GI->getOperand(0)->getType())
return false;
}
if (ValueMap[FI] == GI) {
++FI, ++GI;
continue;
}
if (ValueMap[FI] != NULL)
return false;
for (unsigned i = 0, e = FI->getNumOperands(); i != e; ++i) {
Value *OpF = IgnoreBitcasts(FI->getOperand(i));
Value *OpG = IgnoreBitcasts(GI->getOperand(i));
if (ValueMap[OpF] == OpG)
continue;
if (ValueMap[OpF] != NULL)
return false;
if (OpF->getValueID() != OpG->getValueID() ||
!isEquivalentType(OpF->getType(), OpG->getType()))
return false;
if (isa<PHINode>(FI)) {
if (SpeculationMap[OpF] == NULL)
SpeculationMap[OpF] = OpG;
else if (SpeculationMap[OpF] != OpG)
return false;
continue;
} else if (isa<BasicBlock>(OpF)) {
assert(isa<TerminatorInst>(FI) &&
"BasicBlock referenced by non-Terminator non-PHI");
// This call changes the ValueMap, hence we can't use
// Value *& = ValueMap[...]
if (!equals(cast<BasicBlock>(OpF), cast<BasicBlock>(OpG), ValueMap,
SpeculationMap))
return false;
} else {
if (!compare(OpF, OpG))
return false;
}
ValueMap[OpF] = OpG;
}
ValueMap[FI] = GI;
++FI, ++GI;
} while (FI != FE && GI != GE);
return FI == FE && GI == GE;
}