[llvm-commits] [llvm] r142992 - in /llvm/trunk: lib/VMCore/Instructions.cpp test/Bitcode/shuffle.ll

[Duncan Sands]

Hi Mon Ping,

> The bit code reader tries to look up the constant based on an index.  If it is hasn't encountered the constant yet, it places a placeholder and fixes it up later.  This happens rarely and allows the reader to run in one pass.  Updating the verifier is a good idea.  I'll do that.

thanks for the explanation.  If I understand right, what is special about
shufflevector is that it's not enough that the mask has the right type,
it is also required to be a vector of ConstantInt (or undef).  Presumably
placeholders always have the right type, which is enough to satisfy other
instructions.

Ciao, Duncan.