[SystemZ] Replace subreg_r with subreg_h

Change
  subreg_r32  -> subreg_h32
  subreg_r64  -> subreg_h64
  subreg_hr32 -> subreg_hh32

The subregisters subreg_r32 and subreg_r64 were added to emphasize the
fact that modifying these subregisters may clobber the entire register.
This is not necessarily the case for subreg_h32, et al.

However, the ability to compose subreg_h64 with subreg_r32, and with
subreg_h32 and subreg_l32 at the same time makes the compositions be
treated as non-overlapping (leading to problems when tracking subreg
liveness). See D50468 for more details.

Differential Revision: https://reviews.llvm.org/D50725

llvm-svn: 339778
diff --git a/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp b/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp
index f0f9211..b03b4ed 100644
--- a/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp
@@ -880,10 +880,10 @@
       SystemZ::FP128BitRegClass.contains(SrcReg)) {
     unsigned SrcRegHi =
       RI.getMatchingSuperReg(RI.getSubReg(SrcReg, SystemZ::subreg_h64),
-                             SystemZ::subreg_r64, &SystemZ::VR128BitRegClass);
+                             SystemZ::subreg_h64, &SystemZ::VR128BitRegClass);
     unsigned SrcRegLo =
       RI.getMatchingSuperReg(RI.getSubReg(SrcReg, SystemZ::subreg_l64),
-                             SystemZ::subreg_r64, &SystemZ::VR128BitRegClass);
+                             SystemZ::subreg_h64, &SystemZ::VR128BitRegClass);
 
     BuildMI(MBB, MBBI, DL, get(SystemZ::VMRHG), DestReg)
       .addReg(SrcRegHi, getKillRegState(KillSrc))
@@ -894,10 +894,10 @@
       SystemZ::VR128BitRegClass.contains(SrcReg)) {
     unsigned DestRegHi =
       RI.getMatchingSuperReg(RI.getSubReg(DestReg, SystemZ::subreg_h64),
-                             SystemZ::subreg_r64, &SystemZ::VR128BitRegClass);
+                             SystemZ::subreg_h64, &SystemZ::VR128BitRegClass);
     unsigned DestRegLo =
       RI.getMatchingSuperReg(RI.getSubReg(DestReg, SystemZ::subreg_l64),
-                             SystemZ::subreg_r64, &SystemZ::VR128BitRegClass);
+                             SystemZ::subreg_h64, &SystemZ::VR128BitRegClass);
 
     if (DestRegHi != SrcReg)
       copyPhysReg(MBB, MBBI, DL, DestRegHi, SrcReg, false);