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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"
     17 #include "llvm/CodeGen/MachineFrameInfo.h"
     18 #include "llvm/CodeGen/MachineFunctionPass.h"
     19 #include "llvm/CodeGen/MachineInstrBuilder.h"
     20 #include "llvm/Support/raw_ostream.h"
     21 #include "llvm/Target/TargetMachine.h"
     22 using namespace llvm;
     23 
     24 namespace {
     25   struct XCoreFTAOElim : public MachineFunctionPass {
     26     static char ID;
     27     XCoreFTAOElim() : MachineFunctionPass(ID) {}
     28 
     29     bool runOnMachineFunction(MachineFunction &Fn) override;
     30     MachineFunctionProperties getRequiredProperties() const override {
     31       return MachineFunctionProperties().set(
     32           MachineFunctionProperties::Property::AllVRegsAllocated);
     33     }
     34 
     35     const char *getPassName() const override {
     36       return "XCore FRAME_TO_ARGS_OFFSET Elimination";
     37     }
     38   };
     39   char XCoreFTAOElim::ID = 0;
     40 }
     41 
     42 /// createXCoreFrameToArgsOffsetEliminationPass - returns an instance of the
     43 /// Frame to args offset elimination pass
     44 FunctionPass *llvm::createXCoreFrameToArgsOffsetEliminationPass() {
     45   return new XCoreFTAOElim();
     46 }
     47 
     48 bool XCoreFTAOElim::runOnMachineFunction(MachineFunction &MF) {
     49   const XCoreInstrInfo &TII =
     50       *static_cast<const XCoreInstrInfo *>(MF.getSubtarget().getInstrInfo());
     51   unsigned StackSize = MF.getFrameInfo()->getStackSize();
     52   for (MachineFunction::iterator MFI = MF.begin(), E = MF.end(); MFI != E;
     53        ++MFI) {
     54     MachineBasicBlock &MBB = *MFI;
     55     for (MachineBasicBlock::iterator MBBI = MBB.begin(), EE = MBB.end();
     56          MBBI != EE; ++MBBI) {
     57       if (MBBI->getOpcode() == XCore::FRAME_TO_ARGS_OFFSET) {
     58         MachineInstr *OldInst = MBBI;
     59         unsigned Reg = OldInst->getOperand(0).getReg();
     60         MBBI = TII.loadImmediate(MBB, MBBI, Reg, StackSize);
     61         OldInst->eraseFromParent();
     62       }
     63     }
     64   }
     65   return true;
     66 }
     67