[llvm-commits] [llvm] r138722 - in /llvm/trunk: lib/Analysis/ConstantFolding.cpp lib/Transforms/InstCombine/InstCombineCasts.cpp test/Transforms/InstCombine/cast.ll

[Chris Lattner]

On Aug 28, 2011, at 5:07 AM, Duncan Sands wrote:

> Hi Nadav,
> 
>> Bitcasts are transitive. Bitcast-Bitcast-X becomes Bitcast-X.
> 
> sadly this is not true because you are only allowed to bitcast an mmx type
> to and from a vector type, but you can bitcast vector to and from integers
> etc.

See also CastInst::isEliminableCastPair.

-Chris