Added a virtual method isVectorClearMaskLegal to TLI. It is similar to isShuffleMaskLegal, used to determine if it makes sense to turn a "vector clear" (e.g. pand V, <0, -1, 0, -1> to a shuffle of the vector and a zero vector.
Added a virtual method isVectorClearMaskLegal to TLI. It is similar to
isShuffleMaskLegal, used to determine if it makes sense to turn a
"vector clear" (e.g. pand V, <0, -1, 0, -1> to a shuffle of the vector and
a zero vector.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@27873 91177308-0d34-0410-b5e6-96231b3b80d8

dslab-epfl/asap,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,chubbymaggie/asap,apple/swift-llvm,chubbymaggie/asap,llvm-mirror/llvm,chubbymaggie/asap,llvm-mirror/llvm,dslab-epfl/asap,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,llvm-mirror/llvm,llvm-mirror/llvm,chubbymaggie/asap,chubbymaggie/asap,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,GPUOpen-Drivers/llvm,apple/swift-llvm,dslab-epfl/asap,apple/swift-llvm,dslab-epfl/asap,chubbymaggie/asap,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap