[PPC64] Add vector pack/unpack support from ISA 2.07

This patch adds support for the following new instructions in the
Power ISA 2.07:

  vpksdss
  vpksdus
  vpkudus
  vpkudum
  vupkhsw
  vupklsw

These instructions are available through the vec_packs, vec_packsu,
vec_unpackh, and vec_unpackl built-in interfaces.  These are
lane-sensitive instructions, so the built-ins have different
implementations for big- and little-endian, and the instructions must
be marked as killing the vector swap optimization for now.

The first three instructions perform saturating pack operations.  The
fourth performs a modulo pack operation, which means it can be
represented with a vector shuffle, and conversely the appropriate
vector shuffles may cause this instruction to be generated.  The other
instructions are only generated via built-in support for now.

Appropriate tests have been added.

There is a companion patch to clang for the rest of this support.

llvm-svn: 237499

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.h b/llvm/lib/Target/PowerPC/PPCISelLowering.h
index 33cbb6e5196..81589c8307f 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.h
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.h
@@ -357,6 +357,11 @@ namespace llvm {
     bool isVPKUWUMShuffleMask(ShuffleVectorSDNode *N, unsigned ShuffleKind,
                               SelectionDAG &DAG);
 
+    /// isVPKUDUMShuffleMask - Return true if this is the shuffle mask for a
+    /// VPKUDUM instruction.
+    bool isVPKUDUMShuffleMask(ShuffleVectorSDNode *N, unsigned ShuffleKind,
+                              SelectionDAG &DAG);
+
     /// isVMRGLShuffleMask - Return true if this is a shuffle mask suitable for
     /// a VRGL* instruction with the specified unit size (1,2 or 4 bytes).
     bool isVMRGLShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,