LLVM  3.7.0
XCoreFrameToArgsOffsetElim.cpp
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1 //===-- XCoreFrameToArgsOffsetElim.cpp ----------------------------*- C++ -*-=//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // Replace Pseudo FRAME_TO_ARGS_OFFSET with the appropriate real offset.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "XCore.h"
15 #include "XCoreInstrInfo.h"
16 #include "XCoreSubtarget.h"
20 #include "llvm/Support/Compiler.h"
23 using namespace llvm;
24 
25 namespace {
26  struct XCoreFTAOElim : public MachineFunctionPass {
27  static char ID;
28  XCoreFTAOElim() : MachineFunctionPass(ID) {}
29 
30  bool runOnMachineFunction(MachineFunction &Fn) override;
31 
32  const char *getPassName() const override {
33  return "XCore FRAME_TO_ARGS_OFFSET Elimination";
34  }
35  };
36  char XCoreFTAOElim::ID = 0;
37 }
38 
39 /// createXCoreFrameToArgsOffsetEliminationPass - returns an instance of the
40 /// Frame to args offset elimination pass
42  return new XCoreFTAOElim();
43 }
44 
45 bool XCoreFTAOElim::runOnMachineFunction(MachineFunction &MF) {
46  const XCoreInstrInfo &TII =
47  *static_cast<const XCoreInstrInfo *>(MF.getSubtarget().getInstrInfo());
48  unsigned StackSize = MF.getFrameInfo()->getStackSize();
49  for (MachineFunction::iterator MFI = MF.begin(), E = MF.end(); MFI != E;
50  ++MFI) {
51  MachineBasicBlock &MBB = *MFI;
52  for (MachineBasicBlock::iterator MBBI = MBB.begin(), EE = MBB.end();
53  MBBI != EE; ++MBBI) {
54  if (MBBI->getOpcode() == XCore::FRAME_TO_ARGS_OFFSET) {
55  MachineInstr *OldInst = MBBI;
56  unsigned Reg = OldInst->getOperand(0).getReg();
57  MBBI = TII.loadImmediate(MBB, MBBI, Reg, StackSize);
58  OldInst->eraseFromParent();
59  }
60  }
61  }
62  return true;
63 }
uint64_t getStackSize() const
Return the number of bytes that must be allocated to hold all of the fixed size frame objects...
const TargetSubtargetInfo & getSubtarget() const
getSubtarget - Return the subtarget for which this machine code is being compiled.
MachineFunctionPass - This class adapts the FunctionPass interface to allow convenient creation of pa...
const HexagonInstrInfo * TII
void eraseFromParent()
Unlink 'this' from the containing basic block and delete it.
Reg
All possible values of the reg field in the ModR/M byte.
FRAME_TO_ARGS_OFFSET - This node represents offset from frame pointer to first (possible) on-stack ar...
Definition: ISDOpcodes.h:91
FunctionPass * createXCoreFrameToArgsOffsetEliminationPass()
createXCoreFrameToArgsOffsetEliminationPass - returns an instance of the Frame to args offset elimina...
bundle_iterator< MachineInstr, instr_iterator > iterator
const MachineOperand & getOperand(unsigned i) const
Definition: MachineInstr.h:273
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:294
MachineBasicBlock::iterator loadImmediate(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, unsigned Reg, uint64_t Value) const
MachineFrameInfo * getFrameInfo()
getFrameInfo - Return the frame info object for the current function.
Representation of each machine instruction.
Definition: MachineInstr.h:51
unsigned getReg() const
getReg - Returns the register number.
virtual const TargetInstrInfo * getInstrInfo() const
BasicBlockListType::iterator iterator