[SystemZ] Add back end

This adds the actual lib/Target/SystemZ target files necessary to
implement the SystemZ target.  Note that at this point, the target
cannot yet be built since the configure bits are missing.  Those
will be provided shortly by a follow-on patch.

This version of the patch incorporates feedback from reviews by
Chris Lattner and Anton Korobeynikov.  Thanks to all reviewers!

Patch by Richard Sandiford.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181203 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 47 insertions, 0 deletions

diff --git a/lib/Target/SystemZ/SystemZMCInstLower.h b/lib/Target/SystemZ/SystemZMCInstLower.h
new file mode 100644
index 0000000000..afa72f38ad
--- /dev/null
+++ b/lib/Target/SystemZ/SystemZMCInstLower.h
@@ -0,0 +1,47 @@
+//===-- SystemZMCInstLower.h - Lower MachineInstr to MCInst ----*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SYSTEMZMCINSTLOWER_H
+#define LLVM_SYSTEMZMCINSTLOWER_H
+
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/Compiler.h"
+
+namespace llvm {
+class MCContext;
+class MCInst;
+class MCOperand;
+class MCSymbol;
+class MachineInstr;
+class MachineOperand;
+class Mangler;
+class SystemZAsmPrinter;
+
+class LLVM_LIBRARY_VISIBILITY SystemZMCInstLower {
+  Mangler *Mang;
+  MCContext &Ctx;
+  SystemZAsmPrinter &AsmPrinter;
+
+public:
+  SystemZMCInstLower(Mangler *mang, MCContext &ctx,
+                     SystemZAsmPrinter &asmPrinter);
+
+  // Lower MachineInstr MI to MCInst OutMI.
+  void lower(const MachineInstr *MI, MCInst &OutMI) const;
+
+  // Return an MCOperand for MO.  Return an empty operand if MO is implicit.
+  MCOperand lowerOperand(const MachineOperand& MO) const;
+
+  // Return an MCOperand for MO, given that it equals Symbol + Offset.
+  MCOperand lowerSymbolOperand(const MachineOperand &MO,
+                               const MCSymbol *Symbol, int64_t Offset) const;
+};
+} // end namespace llvm
+
+#endif