http://permalink.gmane.org/gmane.comp.compilers.llvm.devel/81724
This is with reference to the X86 PSAD instruction generation discussion happened in the above link.
This patch contains the Codgen changes. This change is introducing an llvm intrinsic called @llvm.sad() which takes two integer vector input and return an integer result. An ISD::SAD corresponding to this intrinsic is also added. Loop vectorizer or SLP vectorizer can use this intrinsic only after querying the target.
The opposite question was asked on the thread about i32, but can we constraint the return type more than this? (open question, I don't think so)