[SCEV] Fix threshold limit check

[javed.absar]

Summary

I think the correct AddOpsInlineThreshold size to check is after the Add has been merged with Ops.

[mkazantsev]

lib/Analysis/ScalarEvolution.cpp

2437

Given that get Add->getNumOperands() is always non-negative, checking both this and Ops.size() > AddOpsInlineThreshold makes no sense.

What was the motivation of that?

[dfukalov]

any test and/or example of the case?

[mkazantsev]

Test needed, condition should be simplified.

lib/Analysis/ScalarEvolution.cpp

#endif
   while (Idx < Ops.size() && Ops[Idx]->getSCEVType() < scAddExpr)
     ++Idx;
 
   // If there are add operands they would be next.
   if (Idx < Ops.size()) {
     bool DeletedAdd = false;
     while (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Ops[Idx])) {
       if (Ops.size() > AddOpsInlineThreshold ||
-          Add->getNumOperands() > AddOpsInlineThreshold)
+          (Ops.size() + Add->getNumOperands()) > AddOpsInlineThreshold)
         break;
       // If we have an add, expand the add operands onto the end of the operands
       // list.
       Ops.erase(Ops.begin()+Idx);
       Ops.append(Add->op_begin(), Add->op_end());
       DeletedAdd = true;
     }