Add definitions of two subclasses of MipsFrameLowering, Mips16FrameLowering and

MipsSEFrameLowering.

Implement MipsSEFrameLowering::hasReservedCallFrame. Call frames will not be
reserved if there is a call with a large call frame or there are variable sized
objects on the stack.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161090 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Mips/Mips16FrameLowering.cpp

@@ -0,0 +1,82 @@
+//===-- Mips16FrameLowering.cpp - Mips16 Frame Information ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the Mips16 implementation of TargetFrameLowering class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Mips16FrameLowering.h"
+#include "MipsInstrInfo.h"
+#include "MCTargetDesc/MipsBaseInfo.h"
+#include "llvm/Function.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Support/CommandLine.h"
+
+using namespace llvm;
+
+void Mips16FrameLowering::emitPrologue(MachineFunction &MF) const {
+  MachineBasicBlock &MBB = MF.front();
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  const MipsInstrInfo &TII =
+    *static_cast<const MipsInstrInfo*>(MF.getTarget().getInstrInfo());
+  MachineBasicBlock::iterator MBBI = MBB.begin();
+  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+  uint64_t StackSize = MFI->getStackSize();
+
+  // No need to allocate space on the stack.
+  if (StackSize == 0 && !MFI->adjustsStack()) return;
+
+  // Adjust stack.
+  if (isInt<16>(-StackSize))
+    BuildMI(MBB, MBBI, dl, TII.get(Mips::SaveRaF16)).addImm(StackSize);
+}
+
+void Mips16FrameLowering::emitEpilogue(MachineFunction &MF,
+                                 MachineBasicBlock &MBB) const {
+  MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  const MipsInstrInfo &TII =
+    *static_cast<const MipsInstrInfo*>(MF.getTarget().getInstrInfo());
+  DebugLoc dl = MBBI->getDebugLoc();
+  uint64_t StackSize = MFI->getStackSize();
+
+  if (!StackSize)
+    return;
+
+  // Adjust stack.
+  if (isInt<16>(StackSize))
+    // assumes stacksize multiple of 8
+    BuildMI(MBB, MBBI, dl, TII.get(Mips::RestoreRaF16)).addImm(StackSize);
+}
+
+bool Mips16FrameLowering::
+spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+                          MachineBasicBlock::iterator MI,
+                          const std::vector<CalleeSavedInfo> &CSI,
+                          const TargetRegisterInfo *TRI) const {
+  // FIXME: implement.
+  return true;
+}
+
+bool
+Mips16FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
+  // FIXME: implement.
+  return true;
+}
+
+void Mips16FrameLowering::
+processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
+                                     RegScavenger *RS) const {
+}