[SystemZ] Rename subregs and add subreg_h32

Use subreg_hNN and subreg_lNN for the high and low NN bits of a register.
List the low registers first, so that subreg_l32 also means the low 32
bits of a 128-bit register.

Floats are stored in the upper 32 bits of a 64-bit register, so they
should use subreg_h32 rather than subreg_l32.

No behavioral change intended.

llvm-svn: 191659
diff --git a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
index ed75e28..acfb491 100644
--- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
@@ -111,7 +111,7 @@
                         const SystemZTargetMachine &TM,
                         unsigned GPR64, bool IsImplicit) {
   const SystemZRegisterInfo *RI = TM.getRegisterInfo();
-  unsigned GPR32 = RI->getSubReg(GPR64, SystemZ::subreg_32bit);
+  unsigned GPR32 = RI->getSubReg(GPR64, SystemZ::subreg_l32);
   bool IsLive = MBB.isLiveIn(GPR64) || MBB.isLiveIn(GPR32);
   if (!IsLive || !IsImplicit) {
     MIB.addReg(GPR64, getImplRegState(IsImplicit) | getKillRegState(!IsLive));