[Nios2] final infrastructure to provide compilation of a return from a function

This patch includes all missing functionality needed to provide first
compilation of a simple program that just returns from a function.
I've added a test case that checks for "ret" instruction printed in assembly
output.

Patch by Andrei Grischenko (andrei.l.grischenko@intel.com)
Differential revision: https://reviews.llvm.org/D39688

llvm-svn: 320035

1 files changed, 62 insertions, 0 deletions

diff --git a/llvm/lib/Target/Nios2/Nios2MachineFunction.h b/llvm/lib/Target/Nios2/Nios2MachineFunction.h
new file mode 100644
index 00000000000..73baf969479
--- /dev/null
+++ b/llvm/lib/Target/Nios2/Nios2MachineFunction.h
@@ -0,0 +1,62 @@
+//===-- Nios2MachineFunctionInfo.h - Private data used for Nios2 --*- C++ -*-=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the Nios2 specific subclass of MachineFunctionInfo.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_NIOS2_NIOS2MACHINEFUNCTION_H
+#define LLVM_LIB_TARGET_NIOS2_NIOS2MACHINEFUNCTION_H
+
+#include "llvm/CodeGen/MachineFunction.h"
+
+namespace llvm {
+
+/// Nios2FunctionInfo - This class is derived from MachineFunction private
+/// Nios2 target-specific information for each MachineFunction.
+class Nios2FunctionInfo : public MachineFunctionInfo {
+  virtual void anchor();
+
+private:
+  unsigned GlobalBaseReg;
+
+  /// VarArgsFrameOffset - Frame offset to start of varargs area.
+  int VarArgsFrameOffset;
+
+  /// SRetReturnReg - Holds the virtual register into which the sret
+  /// argument is passed.
+  unsigned SRetReturnReg;
+
+  /// IsLeafProc - True if the function is a leaf procedure.
+  bool IsLeafProc;
+
+public:
+  Nios2FunctionInfo()
+      : GlobalBaseReg(0), VarArgsFrameOffset(0), SRetReturnReg(0),
+        IsLeafProc(false) {}
+  explicit Nios2FunctionInfo(MachineFunction &MF)
+      : GlobalBaseReg(0), VarArgsFrameOffset(0), SRetReturnReg(0),
+        IsLeafProc(false) {}
+
+  unsigned getGlobalBaseReg() const { return GlobalBaseReg; }
+  void setGlobalBaseReg(unsigned Reg) { GlobalBaseReg = Reg; }
+
+  int getVarArgsFrameOffset() const { return VarArgsFrameOffset; }
+  void setVarArgsFrameOffset(int Offset) { VarArgsFrameOffset = Offset; }
+
+  unsigned getSRetReturnReg() const { return SRetReturnReg; }
+  void setSRetReturnReg(unsigned Reg) { SRetReturnReg = Reg; }
+
+  void setLeafProc(bool rhs) { IsLeafProc = rhs; }
+  bool isLeafProc() const { return IsLeafProc; }
+};
+
+} // end of namespace llvm
+
+#endif // NIOS2_MACHINE_FUNCTION_INFO_H