[llvm-commits] [llvm] r122183 - in /llvm/trunk/lib/Transforms/InstCombine: InstCombineCalls.cpp InstructionCombining.cpp

[Chris Lattner]

On Dec 19, 2010, at 3:20 PM, Frits van Bommel wrote:

>> 
>> +
>> +        // If the normal result of the add is dead, and the RHS is a constant,
>> +        // we can transform this into a range comparison.
>> +        // overflow = uadd a, -4  -->  overflow = icmp ugt a, 3
>> +        if (ConstantInt *CI = dyn_cast<ConstantInt>(II->getArgOperand(1)))
>> +          return new ICmpInst(ICmpInst::ICMP_UGT, II->getArgOperand(0),
>> +                              ConstantExpr::getNot(CI));
> 
> this also runs on sadd.with.overflow(). This seems fishy to me.
> Shouldn't you at least use a different predicate for that one?

You're absolutely right, that was an oversight on my part.  Fixed in r122204, thanks a lot for catching this!

-Chris