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BranchRange.cpp
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BranchRange.cpp
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#include "llvm/Pass.h"
#include "llvm/IR/Function.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/Transforms/IPO/PassManagerBuilder.h"
using namespace llvm;
namespace
{
struct HppsBranchRange : public FunctionPass
{
static char ID;
HppsBranchRange() : FunctionPass(ID) {}
// Run over a single function
bool runOnFunction(Function &Func) override
{
// --- PLACEHOLDERS/DEFAULTS --- //
// Create a Null Value reference
// Assigned as placeholder when no variable reference available
LLVMContext &context = Func.getContext();
Value *nullValue = ConstantInt::get(Type::getInt32Ty(context), -1);
// Max int range (infinity)
int infMax = std::numeric_limits<int>::max();
int infMin = std::numeric_limits<int>::min();
int maxLoops = 1000;
int iterLoops = 0;
// Create Null range reference
std::pair<int, int> emptyIntPair(infMin, infMax);
std::pair<Value *, std::pair<int, int>> emptyPair(nullValue, emptyIntPair);
std::map<Value *, std::pair<int, int>> emptyMap;
// --- DATA STRUCTURES --- //
// Save cmp instructions to resolve on br instructions
std::map<Value *, CmpInst *> mapCmp;
// List of basic blocks left to cycle
std::vector<BasicBlock *> workList;
// For each basic block, store list of ranges
// Contains list of value reference and current min and max range for that value
// {
// "BB1": { '%k', { 0, 100 } }
// }
std::map<BasicBlock *, std::map<Value *, std::pair<int, int>>> listRange;
// iterator_range<Argument> args = Func.args();
// for (Argument iter = args.begin(); iter != args.end(); iter++)
// {
// errs() << "Param: " << iter.getName() << "\n";
// }
// --- ALGORITHM BEGIN --- //
// Entry basic block into workList (starting point)
workList.push_back(&Func.getEntryBlock());
// Loop on the worklist until all dependencies are resolved
while (workList.size() != 0 && iterLoops < maxLoops)
{
// Get next BasicBlock in workList and remove it
bool hasBeenUpdated = false;
++iterLoops;
BasicBlock *BB = workList.at(0);
workList.erase(workList.begin());
errs() << "\n--- (" << iterLoops << ") " << BB->getName() << " ---\n";
// --- PRINT ALL PREDECESSORS --- //
for (BasicBlock *Pred : predecessors(BB))
{
errs() << "..." << Pred->getName() << "\n";
}
// --- PRINT CURRENT VALUE RANGES INSIDE BLOCK --- //
if (isAlreadyVisited(BB, &listRange))
{
std::map<Value *, std::pair<int, int>> refList = listRange.find(BB)->second;
std::map<Value *, std::pair<int, int>>::iterator resIt;
if (refList.begin() == refList.end())
{
errs() << "___No references\n";
}
for (resIt = refList.begin(); resIt != refList.end(); ++resIt)
{
errs() << "___" << resIt->first->getName() << printRange(resIt->second, infMin, infMax) << "\n";
}
errs() << "\n";
}
else
{
errs() << "___No visited\n\n";
}
// If basic block not already visited, mark as visited
if (!isAlreadyVisited(BB, &listRange))
{
listRange.insert(std::pair<BasicBlock *, std::map<Value *, std::pair<int, int>>>(BB, emptyMap));
}
// Run over all instructions in the basic block
for (BasicBlock::InstListType::iterator it =
BB->getInstList().begin();
it != BB->getInstList().end(); ++it)
{
// Get instruction from iterator
Instruction *I = &*it;
if (auto *cmpInst = dyn_cast<CmpInst>(I)) // COMPLETE
{
errs() << "@Cmp\n";
// Cmp information needed only when at least one reference
if (cmpInst->getOperand(0)->hasName() || cmpInst->getOperand(1)->hasName())
{
if (mapCmp.find(cmpInst) == mapCmp.end())
{
errs() << "NEW: " << cmpInst->getName() << "\n\n";
std::pair<Value *, CmpInst *> newCmpInst(cmpInst, cmpInst);
mapCmp.insert(newCmpInst);
}
}
}
else if (auto *callInst = dyn_cast<CallInst>(I))
{
errs() << "@Call\n";
for (unsigned args = 0; args < callInst->getNumArgOperands(); ++args)
{
Value *argOper = callInst->getArgOperand(args);
if (argOper->hasName())
{
errs() << "Unknown range on " << argOper->getName() << "(" << args << ")\n";
}
}
}
else if (auto *loadInst = dyn_cast<LoadInst>(I))
{
errs() << "@Load\n";
errs() << loadInst->getPointerOperand()->getName() << "\n";
errs() << loadInst->getName() << "\n";
}
else if (auto *selectInst = dyn_cast<SelectInst>(I))
{
errs() << "@Select\n";
errs() << "Condition: " << selectInst->getCondition()->getName() << "\n";
errs() << "True: " << selectInst->getTrueValue()->getName() << "\n";
errs() << "False: " << selectInst->getFalseValue()->getName() << "\n";
}
else if (auto *operInst = dyn_cast<BinaryOperator>(I))
{
errs() << "@Operation\n";
// Get operands from binary operation
Value *oper0 = operInst->getOperand(0);
Value *oper1 = operInst->getOperand(1);
unsigned operCode = operInst->getOpcode();
std::pair<int, int> rangeRef(infMin, infMax);
if (ConstantInt *CI0 = dyn_cast<ConstantInt>(oper0))
{
int constValue0 = CI0->getZExtValue();
// a = 1 + 1 (constant)
if (ConstantInt *CI1 = dyn_cast<ConstantInt>(oper1))
{
int constValue1 = CI1->getZExtValue();
int totConst = binaryOperationResult(operCode, constValue0, constValue1);
rangeRef.first = totConst;
rangeRef.second = totConst;
}
// a = 1 + b
else
{
std::pair<int, int> valueRef = getValueReference(BB, oper1, &listRange, infMin, infMax)->second;
errs() << operInst->getName() << " = " << oper1->getName() << printRange(valueRef, infMin, infMax) << " | " << constValue0 << " [" << BB->getName() << "]\n";
if (valueRef.first != infMin)
{
rangeRef.first = binaryOperationResult(operCode, constValue0, valueRef.first);
}
else
{
rangeRef.first = infMin;
}
if (valueRef.second != infMax)
{
rangeRef.second = binaryOperationResult(operCode, constValue0, valueRef.second);
}
else
{
rangeRef.second = infMax;
}
}
}
else if (ConstantInt *CI1 = dyn_cast<ConstantInt>(oper1))
{
int constValue1 = CI1->getZExtValue();
// a = b + 1
if (oper0->hasName())
{
std::pair<int, int> valueRef = getValueReference(BB, oper0, &listRange, infMin, infMax)->second;
errs() << operInst->getName() << " = " << oper0->getName() << printRange(valueRef, infMin, infMax) << " | " << constValue1 << " [" << BB->getName() << "]\n";
if (valueRef.first != infMin)
{
rangeRef.first = binaryOperationResult(operCode, valueRef.first, constValue1);
}
else
{
rangeRef.first = infMin;
}
if (valueRef.second != infMax)
{
rangeRef.second = binaryOperationResult(operCode, valueRef.second, constValue1);
}
else
{
rangeRef.second = infMax;
}
}
}
// a = b + c
else
{
// a = b + c
if (oper0->hasName() && oper1->hasName())
{
errs() << "BOTH REF: " << oper0->getName() << ", " << oper1->getName() << "\n";
}
// a = b + [%0]
else if (oper0->hasName())
{
if (ConstantInt *CI = dyn_cast<ConstantInt>(oper1))
{
errs() << "BOTH REF: " << oper0->getName() << ", " << CI->getZExtValue() << "\n";
}
}
// a = [%0] + b
else if (oper1->hasName())
{
if (ConstantInt *CI = dyn_cast<ConstantInt>(oper0))
{
errs() << "BOTH REF: " << CI->getZExtValue() << ", " << oper1->getName() << "\n";
}
}
// a = [%0] + [%1]
else
{
if (ConstantInt *CI0 = dyn_cast<ConstantInt>(oper0))
{
if (ConstantInt *CI1 = dyn_cast<ConstantInt>(oper0))
{
errs() << "BOTH REF: " << CI0->getZExtValue() << ", " << CI1->getZExtValue() << "\n";
}
}
}
}
std::pair<Value *, std::pair<int, int>> rangePair(operInst, rangeRef);
errs() << "NEW: " << operInst->getName() << printRange(rangeRef, infMin, infMax) << "\n";
if (hasValueReference(BB, operInst, &listRange))
{
// Add to worklist if range has been updated
std::pair<int, int> valRefSource = getValueReference(BB, operInst, &listRange, infMin, infMax)->second;
hasBeenUpdated = valRefSource.first != rangeRef.first || valRefSource.second != rangeRef.second;
listRange.find(BB)->second.find(operInst)->second.first = rangeRef.first;
listRange.find(BB)->second.find(operInst)->second.second = rangeRef.second;
}
else
{
// Added value reference, add basic block in worklist
hasBeenUpdated = true;
listRange.find(BB)->second.insert(rangePair);
}
}
else if (auto *brInst = dyn_cast<BranchInst>(I))
{
// If no 'if', 'while', 'for' (only one br basic block)
if (brInst->isUnconditional())
{
errs() << "@Br-Simple\n";
BasicBlock *succ = brInst->getSuccessor(0);
for (BasicBlock *Pred : predecessors(BB))
{
if (Pred == succ)
{
errs() << "LOOP on " << Pred->getName() << "\n";
}
}
applySimpleBr(hasBeenUpdated, succ, &listRange, &workList, emptyMap);
}
else
{
errs() << "@Br-Complex\n";
errs() << "Condition: " << brInst->getCondition()->getName() << "\n\n";
// Successor basic blocks (taken and not taken)
BasicBlock *succ0 = brInst->getSuccessor(0);
BasicBlock *succ1 = brInst->getSuccessor(1);
// Get previous cmp values
CmpInst *cmpInst = mapCmp.find(brInst->getCondition())->second;
ICmpInst::Predicate pred = cmpInst->getPredicate();
Value *oper0 = cmpInst->getOperand(0);
Value *oper1 = cmpInst->getOperand(1);
// Default new range pairs and value
// VAL1: Range of the cmp instruction for branch taken
std::pair<int, int> rangeCmpTaken(infMin, infMax);
// VAL2: Range of the cmp instruction for branch not taken
std::pair<int, int> rangeCmpNotTaken(infMin, infMax);
Value *oper = oper0;
// a < b
if (oper0->hasName() && oper1->hasName())
{
errs() << "\n\nUNEXPECTED DOUBLE REFERENCE CMP INSTRUCTION\n\n";
}
// a < 1
else if (oper0->hasName())
{
// Select reference to operand0
oper = oper0;
if (ConstantInt *CI = dyn_cast<ConstantInt>(oper1))
{
// Change range of successors based on reference, constant value, and predicate
computeCmpRange(true, pred, oper, CI->getZExtValue(), &rangeCmpTaken, &rangeCmpNotTaken);
}
}
// 1 < a
else
{
// Select reference to operand0
oper = oper1;
if (ConstantInt *CI = dyn_cast<ConstantInt>(oper0))
{
// Change range of successors based on reference, constant value, and predicate
computeCmpRange(false, pred, oper, CI->getZExtValue(), &rangeCmpTaken, &rangeCmpNotTaken);
}
}
// VAL3: Range in current basic block of the variable in the cmp instruction
std::map<Value *, std::pair<int, int>>::iterator valRefSource = getValueReference(BB, oper, &listRange, infMin, infMax);
// VAL4: Range in taken basic block of the variable in the cmp instruction
std::map<Value *, std::pair<int, int>>::iterator valBranchTaken = getValueReference(succ0, oper, &listRange, infMin, infMax);
// VAL5: Range in not taken basic block of the variable in the cmp instruction
std::map<Value *, std::pair<int, int>>::iterator valBranchNotTaken = getValueReference(succ1, oper, &listRange, infMin, infMax);
// Final computed branch ranges
std::pair<int, int> rangeBranchTaken = brOpe(valRefSource->second, valBranchTaken->second, rangeCmpTaken);
std::pair<int, int> rangeBranchNotTaken = brOpe(valRefSource->second, valBranchNotTaken->second, rangeCmpNotTaken);
errs() << valRefSource->first->getName() << printRange(valRefSource->second, infMin, infMax) << " "
<< valBranchTaken->first->getName() << printRange(valBranchTaken->second, infMin, infMax) << " "
<< printRange(rangeCmpTaken, infMin, infMax) << "\n";
errs() << valRefSource->first->getName() << printRange(valRefSource->second, infMin, infMax) << " "
<< valBranchNotTaken->first->getName() << printRange(valBranchNotTaken->second, infMin, infMax) << " "
<< printRange(rangeCmpNotTaken, infMin, infMax) << "\n";
// Check for new range and add it in case of updates
errs() << succ0->getName() << ": " << printRange(rangeBranchTaken, infMin, infMax) << "\n";
errs() << succ1->getName() << ": " << printRange(rangeBranchNotTaken, infMin, infMax) << "\n\n";
// Check successor0 if already visited
applySimpleBr(true, succ0, &listRange, &workList, emptyMap);
applySimpleBr(true, succ1, &listRange, &workList, emptyMap);
// Update/Insert new range in successors basic blocks
updateValueReference(succ0, oper, rangeBranchTaken, &listRange, infMin, infMax);
updateValueReference(succ1, oper, rangeBranchNotTaken, &listRange, infMin, infMax);
}
}
else if (auto *phiInst = dyn_cast<PHINode>(I))
{
// General ranges and values
Value *operand0 = phiInst->getOperand(0);
Value *operand1 = phiInst->getOperand(1);
BasicBlock *BB0 = phiInst->getIncomingBlock(0);
BasicBlock *BB1 = phiInst->getIncomingBlock(1);
int search0 = searchInBasicBlock(phiInst, BB0, operand0);
int search1 = searchInBasicBlock(phiInst, BB1, operand1);
// Range of the phi variable in current basic block
std::map<Value *, std::pair<int, int>>::iterator valRefSource = getValueReference(BB, phiInst, &listRange, infMin, infMax);
std::pair<int, int> phiPair(infMin, infMax);
errs() << "@Phi: " << phiInst->getName() << " (" << operand0->getName() << "[" << BB0->getName() << "], " << operand1->getName() << " [" << BB1->getName() << "])\n";
// Both referenced values
if (operand0->hasName() && operand1->hasName())
{
std::map<Value *, std::pair<int, int>>::iterator valRef0 = getValueReference(BB0, operand0, &listRange, infMin, infMax);
std::map<Value *, std::pair<int, int>>::iterator valRef1 = getValueReference(BB1, operand1, &listRange, infMin, infMax);
// Apply phi combine operation
errs() << valRefSource->first->getName() << printRange(valRefSource->second, infMin, infMax) << " "
<< valRef0->first->getName() << printRange(valRef0->second, infMin, infMax) << " "
<< valRef1->first->getName() << printRange(valRef1->second, infMin, infMax) << "\n";
phiPair = phiOpe(valRefSource->second, valRef0->second, valRef1->second);
}
// Operator1 is known reference, Operator0 is constant
else if (!operand0->hasName() && operand1->hasName())
{
std::pair<int, int> constPair = getConstantPair(operand0, infMin, infMax);
std::map<Value *, std::pair<int, int>>::iterator valRef = getValueReference(BB1, operand1, &listRange, infMin, infMax);
// Apply phi combine operation
errs() << valRefSource->first->getName() << printRange(valRefSource->second, infMin, infMax) << " "
<< printRange(constPair, infMin, infMax) << " "
<< valRef->first->getName() << printRange(valRef->second, infMin, infMax) << "\n";
phiPair = phiOpe(valRefSource->second, constPair, valRef->second);
// Check if the constant operand is the minimum or maximum value
if (ConstantInt *CI = dyn_cast<ConstantInt>(operand0))
{
int constRangeVal = CI->getZExtValue();
if (search1 == 1)
{
phiPair.first = constRangeVal;
maxTripcount(&phiPair, constRangeVal, phiInst, BB1, operand1, &mapCmp, &listRange, infMin, infMax);
}
else if (search1 == 2)
{
phiPair.second = constRangeVal;
maxTripcount(&phiPair, constRangeVal, phiInst, BB1, operand1, &mapCmp, &listRange, infMin, infMax);
}
}
}
// Operator0 is known reference, Operator1 is constant
else if (!operand1->hasName() && operand0->hasName())
{
std::pair<int, int> constPair = getConstantPair(operand1, infMin, infMax);
std::map<Value *, std::pair<int, int>>::iterator valRef = getValueReference(BB0, operand0, &listRange, infMin, infMax);
// Apply phi combine operation
errs() << valRefSource->first->getName() << printRange(valRefSource->second, infMin, infMax) << " "
<< valRef->first->getName() << printRange(valRef->second, infMin, infMax) << " "
<< printRange(constPair, infMin, infMax) << "\n";
phiPair = phiOpe(valRefSource->second, valRef->second, constPair);
// Check if the constant operand is the minimum or maximum value
if (ConstantInt *CI = dyn_cast<ConstantInt>(operand1))
{
int constRangeVal = CI->getZExtValue();
if (search0 == 1)
{
phiPair.first = constRangeVal;
maxTripcount(&phiPair, constRangeVal, phiInst, BB0, operand0, &mapCmp, &listRange, infMin, infMax);
}
else if (search0 == 2)
{
phiPair.second = constRangeVal;
maxTripcount(&phiPair, constRangeVal, phiInst, BB0, operand0, &mapCmp, &listRange, infMin, infMax);
}
}
}
// Both integers
else if (!operand0->hasName() && !operand1->hasName())
{
// TODO: Phi of two constant values (is it possible?)
errs() << "\n\nTWO INTEGERS\n\n";
}
else
{
errs() << "\n\nUNEXPECTED SITUATION!\n\n";
}
// Update/Insert new phi range to the value in the current basic block
if (phiInst->hasName())
{
updateValueReference(BB, phiInst, phiPair, &listRange, infMin, infMax);
}
}
errs() << "\n";
}
}
// --- PRINT FOUND RANGES FOR EACH BASIC BLOCK VISITED --- //
if (iterLoops == maxLoops)
{
errs() << "--- (MAX ITERATIONS LIMIT) ---\n";
}
errs() << "--- VALUE-RANGES ---\n";
std::map<BasicBlock *, std::map<Value *, std::pair<int, int>>>::iterator resIt;
for (resIt = listRange.begin(); resIt != listRange.end(); ++resIt)
{
errs() << "BB: " << resIt->first->getName() << "\n";
std::map<Value *, std::pair<int, int>> listBB = resIt->second;
while (!listBB.empty())
{
std::map<Value *, std::pair<int, int>>::iterator pairBB = listBB.begin();
int intRange = pairBB->second.first == infMin || pairBB->second.second == infMax ? infMax : std::abs(pairBB->second.second - pairBB->second.first) + 1;
int numOfBit = intRange == infMax ? 32 : std::ceil(intRange <= 2 ? 1 : std::log2(intRange)) + 1;
errs() << " " << pairBB->first->getName() << printRange(pairBB->second, infMin, infMax) << " = ";
if (pairBB->second.first != infMin && pairBB->second.second != infMax)
{
errs() << intRange << " {" << numOfBit << "bit}\n";
}
else
{
errs() << "MAX\n";
}
listBB.erase(listBB.begin());
}
errs() << "\n";
}
return false;
}
// Compute and update maximum range of value add/sub in a loop
void maxTripcount(std::pair<int, int> *tripPair, int baseVal, Value *inst, BasicBlock *BB, Value *operand, std::map<Value *, CmpInst *> *mapCmp, std::map<BasicBlock *, std::map<Value *, std::pair<int, int>>> *listRange, int infMin, int infMax)
{
int tripcount = -1;
for (BasicBlock::InstListType::iterator loopIt =
BB->getInstList().begin();
loopIt != BB->getInstList().end(); ++loopIt)
{
Instruction *loopI = &*loopIt;
// Search br instruction, if successor is same as predcessor, then is a loop
if (auto *brInst = dyn_cast<BranchInst>(loopI))
{
if (brInst->isUnconditional())
{
BasicBlock *succ = brInst->getSuccessor(0);
for (BasicBlock *Pred : predecessors(BB))
{
// Successor same as predecessor
if (Pred == succ)
{
for (BasicBlock::InstListType::iterator subIt =
succ->getInstList().begin();
subIt != succ->getInstList().end(); ++subIt)
{
Instruction *subI = &*subIt;
if (auto *brInst = dyn_cast<BranchInst>(subI))
{
if (!(brInst->isUnconditional()))
{
// Successor basic blocks (taken and not taken)
BasicBlock *succ0 = brInst->getSuccessor(0);
// BasicBlock *succ1 = brInst->getSuccessor(1);
// Get previous cmp values
CmpInst *cmpInst = mapCmp->find(brInst->getCondition())->second;
ICmpInst::Predicate pred = cmpInst->getPredicate();
Value *oper0 = cmpInst->getOperand(0);
Value *oper1 = cmpInst->getOperand(1);
// Default new range pairs and value
// VAL1: Range of the cmp instruction for branch taken
std::pair<int, int> rangeCmpTaken(infMin, infMax);
std::pair<int, int> rangeCmpNotTaken(infMin, infMax);
Value *oper = oper0;
// a < b
if (oper0->hasName() && oper1->hasName())
{
errs() << "\n\nUNEXPECTED DOUBLE REFERENCE CMP INSTRUCTION\n\n";
}
// a < 1
else if (oper0->hasName())
{
// Select reference to operand0
oper = oper0;
if (ConstantInt *CI = dyn_cast<ConstantInt>(oper1))
{
// Change range of successors based on reference, constant value, and predicate
computeCmpRange(true, pred, oper, CI->getZExtValue(), &rangeCmpTaken, &rangeCmpNotTaken);
}
}
// 1 < a
else
{
// Select reference to operand0
oper = oper1;
if (ConstantInt *CI = dyn_cast<ConstantInt>(oper0))
{
// Change range of successors based on reference, constant value, and predicate
computeCmpRange(false, pred, oper, CI->getZExtValue(), &rangeCmpTaken, &rangeCmpNotTaken);
}
}
// VAL3: Range in current basic block of the variable in the cmp instruction
std::map<Value *, std::pair<int, int>>::iterator valRefSource = getValueReference(BB, oper, listRange, infMin, infMax);
// VAL4: Range in taken basic block of the variable in the cmp instruction
std::map<Value *, std::pair<int, int>>::iterator valBranchTaken = getValueReference(succ0, oper, listRange, infMin, infMax);
// Final computed branch ranges
std::pair<int, int> rangeBranchTaken = brOpe(valRefSource->second, valBranchTaken->second, rangeCmpTaken);
if (oper != inst && rangeBranchTaken.first != infMin && rangeBranchTaken.second != infMax)
{
tripcount = std::abs(rangeBranchTaken.second - rangeBranchTaken.first) + 1;
}
}
}
}
// Search add/sub instruction
if (tripcount != -1)
{
errs() << "Tripcount " << tripcount << "\n";
for (BasicBlock::InstListType::iterator subIt =
BB->getInstList().begin();
subIt != BB->getInstList().end(); ++subIt)
{
Instruction *subI = &*subIt;
if (auto *operInst = dyn_cast<BinaryOperator>(subI))
{
// Add/Sub in which the result is the operand in the phi instruction
if (operInst->getName() == operand->getName())
{
Value *oper0 = operInst->getOperand(0);
Value *oper1 = operInst->getOperand(1);
unsigned operCode = operInst->getOpcode();
if (oper0->getName() == inst->getName())
{
if (ConstantInt *CI = dyn_cast<ConstantInt>(oper1))
{
int constVal = CI->getZExtValue();
// a = a + 1 || a - (-1) -> Always growing
if ((operCode == Instruction::Add && constVal >= 0) || (operCode == Instruction::Sub && constVal <= 0))
{
errs() << "Sum " << baseVal << " on " << constVal << " for " << tripcount << "\n";
errs() << "=" << ((constVal * tripcount) + baseVal) << "\n";
tripPair->first = baseVal;
tripPair->second = ((constVal * tripcount) + baseVal);
}
// a = a + (-1) || a - 1 -> Always smaller
else if ((operCode == Instruction::Add && constVal <= 0) || (operCode == Instruction::Sub && constVal >= 0))
{
errs() << "Sum " << baseVal << " on " << constVal << " for " << tripcount << "\n";
errs() << "=" << ((-constVal * tripcount) + baseVal) << "\n";
tripPair->first = ((-constVal * tripcount) + baseVal);
tripPair->second = baseVal;
}
}
}
else if (oper1->getName() == inst->getName())
{
if (ConstantInt *CI = dyn_cast<ConstantInt>(oper0))
{
int constVal = CI->getZExtValue();
// a = a + 1 || a - (-1) -> Always growing
if ((operCode == Instruction::Add && constVal >= 0) || (operCode == Instruction::Sub && constVal <= 0))
{
errs() << "Sum " << baseVal << " on " << constVal << " for " << tripcount << "\n";
errs() << "=" << ((constVal * tripcount) + baseVal) << "\n";
tripPair->first = baseVal;
tripPair->second = ((constVal * tripcount) + baseVal);
}
// a = a + (-1) || a - 1 -> Always smaller
else if ((operCode == Instruction::Add && constVal <= 0) || (operCode == Instruction::Sub && constVal >= 0))
{
errs() << "Sum " << baseVal << " on " << constVal << " for " << tripcount << "\n";
errs() << "=" << ((-constVal * tripcount) + baseVal) << "\n";
tripPair->first = ((-constVal * tripcount) + baseVal);
tripPair->second = baseVal;
}
}
}
}
}
}
}
}
}
}
}
}
}
// 1: The value is found and always grows higher
// 2: The value is found and always grows smaller
int searchInBasicBlock(Value *inst, BasicBlock *BB, Value *operand)
{
bool isSum = false, isSub = false, isFound = false;
for (BasicBlock::InstListType::iterator subIt =
BB->getInstList().begin();
subIt != BB->getInstList().end(); ++subIt)
{
Instruction *subI = &*subIt;
if (auto *operInst = dyn_cast<BinaryOperator>(subI))
{
if (operInst->getName() == operand->getName())
{
Value *oper0 = operInst->getOperand(0);
Value *oper1 = operInst->getOperand(1);
unsigned operCode = operInst->getOpcode();
if (oper0->getName() == inst->getName())
{
if (ConstantInt *CI = dyn_cast<ConstantInt>(oper1))
{
int constVal = CI->getZExtValue();
// a = a + 1 || a - (-1) -> Always growing
if ((operCode == Instruction::Add && constVal >= 0) || (operCode == Instruction::Sub && constVal <= 0))
{
isSum = true;
isFound = true;
}
// a = a + (-1) || a - 1 -> Always smaller
else if ((operCode == Instruction::Add && constVal <= 0) || (operCode == Instruction::Sub && constVal >= 0))
{
isSub = true;
isFound = true;
}
}
}
else if (oper1->getName() == inst->getName())
{
if (ConstantInt *CI = dyn_cast<ConstantInt>(oper0))
{
int constVal = CI->getZExtValue();
// a = a + 1 || a - (-1) -> Always growing
if ((operCode == Instruction::Add && constVal >= 0) || (operCode == Instruction::Sub && constVal <= 0))
{
isSum = true;
isFound = true;
}
// a = a + (-1) || a - 1 -> Always smaller
else if ((operCode == Instruction::Add && constVal <= 0) || (operCode == Instruction::Sub && constVal >= 0))
{
isSub = true;
isFound = true;
}
}
}
}
}
}
// Found, but only sum xor sub
if (isFound && isSum && !isSub)
{
return 1;
}
else if (isFound && !isSum && isSub)
{
return 2;
}
return 0;
}
// If basic block not already visited and not already inside workList, insert it in workList
void applySimpleBr(bool isUpdated, BasicBlock *BB, std::map<BasicBlock *, std::map<Value *, std::pair<int, int>>> *listRange, std::vector<BasicBlock *> *workList, std::map<Value *, std::pair<int, int>> emptyMap)
{
bool isVisited = isAlreadyVisited(BB, listRange);
if (!isVisited)
{
listRange->insert(std::pair<BasicBlock *, std::map<Value *, std::pair<int, int>>>(BB, emptyMap));
}
bool isInWL = isInWorkList(BB, workList);
if ((!isVisited || isUpdated) && !isInWL)
{
errs() << "+ " << BB->getName() << " (notVisited=" << !isVisited << ", isUpdated=" << isUpdated << ")\n";
workList->push_back(BB);
}
}
// Min of minimum values, max of maximum values
std::pair<int, int> unionOpe(std::pair<int, int> range0, std::pair<int, int> range1)
{
return std::pair<int, int>(std::min(range0.first, range1.first), std::max(range0.second, range1.second));
}
// Max of minimum values, min of maximum values
std::pair<int, int> interOpe(std::pair<int, int> range0, std::pair<int, int> range1)
{
return std::pair<int, int>(std::max(range0.first, range1.first), std::min(range0.second, range1.second));
}
// Range combining operation for phi instructions
std::pair<int, int> phiOpe(std::pair<int, int> rangeOriginal, std::pair<int, int> rangeSource0, std::pair<int, int> rangeSource1)
{
return interOpe(rangeOriginal, unionOpe(rangeSource0, rangeSource1));
}
// Range combining operation for br-complex instructions
std::pair<int, int> brOpe(std::pair<int, int> rangeSource, std::pair<int, int> rangeDestination, std::pair<int, int> rangeBranch)
{
return interOpe(rangeBranch, interOpe(rangeSource, rangeDestination));
}
// Compute binary operation (+ or -) result
int binaryOperationResult(unsigned binOper, int value1, int value2)
{
if (binOper == Instruction::Add)
{
return value1 + value2;
}
else if (binOper == Instruction::Sub)
{
return value1 - value2;
}
return value1 + value2;
}
// Computes ranges from CMP instruction (<, >, <=, >=)
void computeCmpRange(bool isRefOper0, ICmpInst::Predicate pred, Value *oper, int cmpValue, std::pair<int, int> *rangeSuccessor0, std::pair<int, int> *rangeSuccessor1)
{
if (pred == ICmpInst::ICMP_SLT)
{
// a < 1
if (isRefOper0)
{
errs() << oper->getName() << " < " << cmpValue << "\n";
rangeSuccessor0->second = cmpValue - 1;
rangeSuccessor1->first = cmpValue;
}
// 1 < a
else
{
errs() << cmpValue << " < " << oper->getName() << "\n";
rangeSuccessor0->first = cmpValue + 1;
rangeSuccessor1->second = cmpValue;
}
}
else if (pred == ICmpInst::ICMP_ULT)
{
// a < 1 [unsigned]
if (isRefOper0)
{
errs() << oper->getName() << " < " << cmpValue << " [unsigned]\n";
rangeSuccessor0->first = 0;
rangeSuccessor0->second = cmpValue - 1;
rangeSuccessor1->first = cmpValue;
}
// 1 < a (a > 1) [unsigned]
else
{
errs() << cmpValue << " < " << oper->getName() << " [unsigned]\n";
rangeSuccessor0->first = cmpValue + 1;
rangeSuccessor1->first = 0;
rangeSuccessor1->second = cmpValue;
}
}
else if (pred == ICmpInst::ICMP_SLE)
{
// a <= 1
if (isRefOper0)
{
errs() << oper->getName() << " <= " << cmpValue << "\n";
rangeSuccessor0->second = cmpValue;
rangeSuccessor1->first = cmpValue + 1;
}
// 1 <= a
else
{
errs() << cmpValue << " <= " << oper->getName() << "\n";
rangeSuccessor0->first = cmpValue;
rangeSuccessor1->second = cmpValue - 1;
}
}
else if (pred == ICmpInst::ICMP_SGT)
{
// a > 1
if (isRefOper0)
{
errs() << oper->getName() << " > " << cmpValue << "\n";
rangeSuccessor0->first = cmpValue + 1;
rangeSuccessor1->second = cmpValue;
}
// 1 > a
else
{
errs() << cmpValue << " > " << oper->getName() << "\n";
rangeSuccessor0->second = cmpValue - 1;
rangeSuccessor1->first = cmpValue;
}
}
else if (pred == ICmpInst::ICMP_UGT)
{
// a > 1
if (isRefOper0)
{
errs() << oper->getName() << " > " << cmpValue << "\n";
rangeSuccessor0->first = cmpValue + 1;
rangeSuccessor1->first = 0;
rangeSuccessor1->second = cmpValue;
}
// 1 > a
else
{
errs() << cmpValue << " > " << oper->getName() << "\n";
rangeSuccessor0->first = cmpValue - 1;
rangeSuccessor0->second = cmpValue - 1;
rangeSuccessor1->first = cmpValue;
}
}
else if (pred == ICmpInst::ICMP_SGE)
{
// a >= 1
if (isRefOper0)
{
errs() << oper->getName() << " >= " << cmpValue << "\n";
rangeSuccessor0->first = cmpValue;
rangeSuccessor1->second = cmpValue - 1;
}
// 1 >= a
else
{
errs() << cmpValue << " >= " << oper->getName() << "\n";
rangeSuccessor0->second = cmpValue;
rangeSuccessor1->first = cmpValue + 1;
}
}
else if (pred == ICmpInst::ICMP_EQ)
{
// a == 1
errs() << oper->getName() << " == " << cmpValue << "\n";
rangeSuccessor0->first = cmpValue;
rangeSuccessor0->second = cmpValue;
}
}
// Check if given BasicBlock is already visited in listRange
bool isAlreadyVisited(BasicBlock *next, std::map<BasicBlock *, std::map<Value *, std::pair<int, int>>> *listRange)
{
return listRange->find(next) != listRange->end();
}
// Update or insert new Value/Pair into basic block
void updateValueReference(BasicBlock *BB, Value *operand, std::pair<int, int> pairRange, std::map<BasicBlock *, std::map<Value *, std::pair<int, int>>> *listRange, int infMin, int infMax)
{
if (hasValueReference(BB, operand, listRange))
{
listRange->find(BB)->second.find(operand)->second.first = pairRange.first;
listRange->find(BB)->second.find(operand)->second.second = pairRange.second;
errs() << "UPDATE: ";
}
else
{
// Insert reference
std::pair<Value *, std::pair<int, int>> newPairRange(operand, pairRange);
listRange->find(BB)->second.insert(newPairRange);
errs() << "NEW: ";
}
// Update reference
errs() << operand->getName() << printRange(pairRange, infMin, infMax) << " in " << BB->getName() << "\n";
}
// Check if given BasicBlock is already visited in listRange
bool hasValueReference(BasicBlock *next, Value *operand, std::map<BasicBlock *, std::map<Value *, std::pair<int, int>>> *listRange)
{
// No reference if never visited
if (!isAlreadyVisited(next, listRange))
{
return false;
}
return listRange->find(next)->second.find(operand) != listRange->find(next)->second.end();
}
// Get value and its range from listRange
std::map<Value *, std::pair<int, int>>::iterator getValueReference(BasicBlock *BB, Value *operand, std::map<BasicBlock *, std::map<Value *, std::pair<int, int>>> *listRange, int infMin, int infMax)
{
if (hasValueReference(BB, operand, listRange))
{
return listRange->find(BB)->second.find(operand);
}
// Unknown variables from -Inf to +Inf
std::pair<int, int> emptyIntPair(infMin, infMax);
std::map<Value *, std::pair<int, int>> emptyPair;
emptyPair[operand] = emptyIntPair;
return emptyPair.begin();
}
std::pair<int, int> getConstantPair(Value *operand, int infMin, int infMax)