Sanjay Patel a06d989552 [ValueTracking] improve ComputeNumSignBits for vector constants ...

This is similar to the computeKnownBits improvement in rL268479. 
There's probably more we can do for vector logic instructions, but 
this should let us see non-splat constant masking ops that can
become vector selects instead of and/andn/or sequences.

Differential Revision: http://reviews.llvm.org/D21610

llvm-svn: 273459

2016-06-22 19:20:59 +00:00

158 KiB

Raw Blame History

View Raw