+ RHSRange = ConstantRange(RHS->getValue(), RHS->getValue()+1);
+ }
+
+ // NOTE: We're currently limited by the set of operations that ConstantRange
+ // can evaluate symbolically. Enhancing that set will allows us to analyze
+ // more definitions.
+ switch (BBI->getOpcode()) {
+ case Instruction::Add:
+ Result.markConstantRange(LHSRange.add(RHSRange));
+ break;
+ case Instruction::Sub:
+ Result.markConstantRange(LHSRange.sub(RHSRange));
+ break;
+ case Instruction::Mul:
+ Result.markConstantRange(LHSRange.multiply(RHSRange));
+ break;
+ case Instruction::UDiv:
+ Result.markConstantRange(LHSRange.udiv(RHSRange));
+ break;
+ case Instruction::Shl:
+ Result.markConstantRange(LHSRange.shl(RHSRange));
+ break;
+ case Instruction::LShr:
+ Result.markConstantRange(LHSRange.lshr(RHSRange));
+ break;
+ case Instruction::Trunc:
+ Result.markConstantRange(LHSRange.truncate(ResultTy->getBitWidth()));
+ break;
+ case Instruction::SExt:
+ Result.markConstantRange(LHSRange.signExtend(ResultTy->getBitWidth()));
+ break;
+ case Instruction::ZExt:
+ Result.markConstantRange(LHSRange.zeroExtend(ResultTy->getBitWidth()));
+ break;
+ case Instruction::BitCast:
+ Result.markConstantRange(LHSRange);
+ break;
+ case Instruction::And:
+ Result.markConstantRange(LHSRange.binaryAnd(RHSRange));
+ break;
+ case Instruction::Or:
+ Result.markConstantRange(LHSRange.binaryOr(RHSRange));
+ break;
+
+ // Unhandled instructions are overdefined.
+ default:
+ DEBUG(dbgs() << " compute BB '" << BB->getName()
+ << "' - overdefined because inst def found.\n");
+ Result.markOverdefined();
+ break;