[llvm-dev] Suspicious code in WholeProgramDevirt.cpp?

[<Alexander G. Riccio> via llvm-dev]

In DevirtModule::tryUniqueRetValOpt, there's a lambda that starts like this:

// IsOne controls whether we look for a 0 or a 1.
  auto tryUniqueRetValOptFor = [&](bool IsOne) {
    const BitSetInfo *UniqueBitSet = 0;
    for (const VirtualCallTarget &Target : TargetsForSlot) {
      if (Target.RetVal == IsOne ? 1 : 0) {
        if (UniqueBitSet)
          return false;
        UniqueBitSet = Target.BS;
      }
    }

I'm working on a patch to turn up the warning levels that LLVM compiles at,
and I got a new warning:

C4805 '==': unsafe mix of type 'const uint64_t' and type 'bool' in operation


...pointing at this line:

if (Target.RetVal == IsOne ? 1 : 0) {


It looks to me like that, instead of comparing Target.RetVal *to* 1 or 0,
it's comparing Target.RetVal *to* IsOne, which I doubt is the intended
outcome!

What's up with that? Is that a bug?

Sincerely,
Alexander Riccio
--
"Change the world or go home."
about.me/ariccio

<http://about.me/ariccio>
If left to my own devices, I will build more.
⁂
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