void vSSA::createSigmasIfNeeded(BasicBlock *BB)
{
TerminatorInst *ti = BB->getTerminator();
// If the condition used in the terminator instruction is a Comparison instruction:
//for each operand of the CmpInst, create sigmas, depending on some conditions
/*
if(isa<BranchInst>(ti)){
BranchInst * bc = cast<BranchInst>(ti);
if(bc->isConditional()){
Value * cond = bc->getCondition();
CmpInst *comparison = dyn_cast<CmpInst>(cond);
for (User::const_op_iterator it = comparison->op_begin(), e = comparison->op_end(); it != e; ++it) {
Value *operand = *it;
if (isa<Instruction>(operand) || isa<Argument>(operand)) {
insertSigmas(ti, operand);
}
}
}
}
*/
// CASE 1: Branch Instruction
BranchInst *bi = NULL;
SwitchInst *si = NULL;
if ((bi = dyn_cast<BranchInst>(ti))) {
if (bi->isConditional()) {
Value *condition = bi->getCondition();
ICmpInst *comparison = dyn_cast<ICmpInst>(condition);
if (comparison) {
// Create sigmas for ICmp operands
for (User::const_op_iterator opit = comparison->op_begin(), opend = comparison->op_end(); opit != opend; ++opit) {
Value *operand = *opit;
if (isa<Instruction>(operand) || isa<Argument>(operand)) {
insertSigmas(ti, operand);
// If the operand is a result of a indirect instruction (e.g. ZExt, SExt, Trunc),
// Create sigmas for the operands of the operands too
CastInst *cinst = NULL;
if ((cinst = dyn_cast<CastInst>(operand))) {
insertSigmas(ti, cinst->getOperand(0));
}
}
}
}
}
}
// CASE 2: Switch Instruction
else if ((si = dyn_cast<SwitchInst>(ti))) {
Value *condition = si->getCondition();
if (isa<Instruction>(condition) || isa<Argument>(condition)) {
insertSigmas(ti, condition);
// If the operand is a result of a indirect instruction (e.g. ZExt, SExt, Trunc),
// Create sigmas for the operands of the operands too
CastInst *cinst = NULL;
if ((cinst = dyn_cast<CastInst>(condition))) {
insertSigmas(ti, cinst->getOperand(0));
}
}
}
}
