Add support for spilling VRSAVE on PPC

Although there is only one Altivec VRSAVE register, it is a member of
a register class, and we need the ability to spill it. Because this
register is normally callee-preserved and handled by special code this
has never before been necessary. However, this capability will be required by
a forthcoming commit adding SjLj support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177654 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCInstrInfo.cpp b/lib/Target/PowerPC/PPCInstrInfo.cpp
index 378312c..2b71f67 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ b/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -539,6 +539,12 @@
                                                getKillRegState(isKill)),
                                        FrameIdx));
     NonRI = true;
+  } else if (PPC::VRSAVERCRegClass.hasSubClassEq(RC)) {
+    NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::SPILL_VRSAVE))
+                                       .addReg(SrcReg,
+                                               getKillRegState(isKill)),
+                                       FrameIdx));
+    NonRI = true;
   } else {
     llvm_unreachable("Unknown regclass!");
   }
@@ -647,6 +653,12 @@
     NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::LVX), DestReg),
                                        FrameIdx));
     NonRI = true;
+  } else if (PPC::VRSAVERCRegClass.hasSubClassEq(RC)) {
+    NewMIs.push_back(addFrameReference(BuildMI(MF, DL,
+                                               get(PPC::RESTORE_VRSAVE),
+                                               DestReg),
+                                       FrameIdx));
+    NonRI = true;
   } else {
     llvm_unreachable("Unknown regclass!");
   }