[SystemZ] Model access registers as LLVM registers

Add the 16 access registers as LLVM registers.  This allows removing
a lot of special cases in the assembler and disassembler where we
were handling access registers; this can all just use the generic
register code now.

Also add a bunch of instructions to operate on access registers,
for assembler/disassembler use only.  No change in code generation
intended.

llvm-svn: 286283

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/Target/SystemZ/SystemZRegisterInfo.cpp b/llvm/lib/Target/SystemZ/SystemZRegisterInfo.cpp
index b5e5fd4bfc4..6ef8000d6f4 100644
--- a/llvm/lib/Target/SystemZ/SystemZRegisterInfo.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZRegisterInfo.cpp
@@ -59,6 +59,11 @@ SystemZRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
   Reserved.set(SystemZ::R15L);
   Reserved.set(SystemZ::R15H);
   Reserved.set(SystemZ::R14Q);
+
+  // A0 and A1 hold the thread pointer.
+  Reserved.set(SystemZ::A0);
+  Reserved.set(SystemZ::A1);
+
   return Reserved;
 }