[PowerPC] Implement the vpopcnt instructions for POWER8

Patch by Kit Barton.

Add the vector population count instructions for byte, halfword, word,
and doubleword sizes.  There are two major changes here:

    PPCISelLowering.cpp: Make CTPOP legal for vector types.
    PPCRegisterInfo.td: Added v2i64 to the VRRC register
      definition. This is needed for the doubleword variations of the
      integer ops that were added in P8. 

Test Plan

Test the instruction vpcnt* encoding/decoding in ppc64-encoding-vmx.s

Test the generation of the vpopcnt instructions for various vector
data types.  When adding the v2i64 type to the Vector Register set, I
also needed to add the appropriate bit conversion patterns between
v2i64 and the existing vector types.  Testing for these conversions
were also added in the test case by passing a different vector type as
a parameter into the test functions.  There is also a run step that
will ensure the vpopcnt instructions are generated when the vsx
feature is disabled.

llvm-svn: 228046

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
index 9aaf3ab75d6..e025a3bbcf5 100644
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
@@ -65,6 +65,7 @@ void PPCSubtarget::initializeEnvironment() {
   HasQPX = false;
   HasVSX = false;
   HasP8Vector = false;
+  HasP8Altivec = false;
   HasFCPSGN = false;
   HasFSQRT = false;
   HasFRE = false;