Replace PowerPCPEI.cpp with target independant PrologEpilogInserter

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15746 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 326 deletions

diff --git a/lib/Target/PowerPC/PowerPCPEI.cpp b/lib/Target/PowerPC/PowerPCPEI.cpp
deleted file mode 100644
index eda17ac708..0000000000
--- a/lib/Target/PowerPC/PowerPCPEI.cpp
+++ /dev/null
@@ -1,326 +0,0 @@
-//===-- PrologEpilogInserter.cpp - Insert Prolog/Epilog code in function --===//
-// 
-//                     The LLVM Compiler Infrastructure
-//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-// 
-//===----------------------------------------------------------------------===//
-//
-// This pass is responsible for finalizing the functions frame layout, saving
-// callee saved registers, and for emitting prolog & epilog code for the
-// function.
-//
-// This pass must be run after register allocation.  After this pass is
-// executed, it is illegal to construct MO_FrameIndex operands.
-//
-//===----------------------------------------------------------------------===//
-//
-// FIXME: The contents of this file should be merged with the target generic
-// CodeGen/PrologEpilogInserter.cpp
-//
-//===----------------------------------------------------------------------===//
-
-#include "PowerPC.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/MRegisterInfo.h"
-#include "llvm/Target/TargetFrameInfo.h"
-#include "llvm/Target/TargetInstrInfo.h"
-#include "Support/Debug.h"
-using namespace llvm;
-
-namespace {
-  struct PPCPEI : public MachineFunctionPass {
-    const char *getPassName() const {
-      return "PowerPC Frame Finalization & Prolog/Epilog Insertion";
-    }
-
-    /// runOnMachineFunction - Insert prolog/epilog code and replace abstract
-    /// frame indexes with appropriate references.
-    ///
-    bool runOnMachineFunction(MachineFunction &Fn) {
-      RegsToSave.clear();
-      StackSlots.clear();
-      
-      // Scan the function for modified caller saved registers and insert spill
-      // code for any caller saved registers that are modified.  Also calculate
-      // the MaxCallFrameSize and HasCalls variables for the function's frame
-      // information and eliminates call frame pseudo instructions.
-      calculateCallerSavedRegisters(Fn);
-
-      // Calculate actual frame offsets for all of the abstract stack objects...
-      calculateFrameObjectOffsets(Fn);
-
-      // Add prolog and epilog code to the function.
-      insertPrologEpilogCode(Fn);
-      
-      // Add register spills and fills before prolog and after epilog so that in
-      // the event of a very large fixed size alloca, we don't have to do
-      // anything weird.
-      saveCallerSavedRegisters(Fn);
-
-      // Replace all MO_FrameIndex operands with physical register references
-      // and actual offsets.
-      //
-      replaceFrameIndices(Fn);
-      return true;
-    }
-
-  private:
-    std::vector<unsigned> RegsToSave;
-    std::vector<int> StackSlots;
-
-    void calculateCallerSavedRegisters(MachineFunction &Fn);
-    void saveCallerSavedRegisters(MachineFunction &Fn);
-    void calculateFrameObjectOffsets(MachineFunction &Fn);
-    void replaceFrameIndices(MachineFunction &Fn);
-    void insertPrologEpilogCode(MachineFunction &Fn);
-  };
-}
-
-
-/// createPowerPCPEI - This function returns a pass that inserts
-/// prolog and epilog code, and eliminates abstract frame references.
-///
-FunctionPass *llvm::createPowerPCPEI() { return new PPCPEI(); }
-
-
-/// calculateCallerSavedRegisters - Scan the function for modified caller saved
-/// registers.  Also calculate the MaxCallFrameSize and HasCalls variables for
-/// the function's frame information and eliminates call frame pseudo
-/// instructions.
-///
-void PPCPEI::calculateCallerSavedRegisters(MachineFunction &Fn) {
-  const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
-  const TargetFrameInfo &FrameInfo = *Fn.getTarget().getFrameInfo();
-
-  // Get the callee saved register list...
-  const unsigned *CSRegs = RegInfo->getCalleeSaveRegs();
-
-  // Get the function call frame set-up and tear-down instruction opcode
-  int FrameSetupOpcode   = RegInfo->getCallFrameSetupOpcode();
-  int FrameDestroyOpcode = RegInfo->getCallFrameDestroyOpcode();
-
-  // Early exit for targets which have no callee saved registers and no call
-  // frame setup/destroy pseudo instructions.
-  if ((CSRegs == 0 || CSRegs[0] == 0) &&
-      FrameSetupOpcode == -1 && FrameDestroyOpcode == -1)
-    return;
-
-  // This bitset contains an entry for each physical register for the target...
-  std::vector<bool> ModifiedRegs(RegInfo->getNumRegs());
-  unsigned MaxCallFrameSize = 0;
-  bool HasCalls = false;
-
-  for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB)
-    for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); )
-      if (I->getOpcode() == FrameSetupOpcode ||
-          I->getOpcode() == FrameDestroyOpcode) {
-	assert(I->getNumOperands() == 1 && "Call Frame Setup/Destroy Pseudo"
-	       " instructions should have a single immediate argument!");
-	unsigned Size = I->getOperand(0).getImmedValue();
-	if (Size > MaxCallFrameSize) MaxCallFrameSize = Size;
-	HasCalls = true;
-	RegInfo->eliminateCallFramePseudoInstr(Fn, *BB, I++);
-      } else {
-	for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
-	  MachineOperand &MO = I->getOperand(i);
-	  if (MO.isRegister() && MO.isDef()) {
-            assert(MRegisterInfo::isPhysicalRegister(MO.getReg()) &&
-                   "Register allocation must be performed!");
-	    ModifiedRegs[MO.getReg()] = true;         // Register is modified
-          }
-        }
-	++I;
-      }
-
-  MachineFrameInfo *FFI = Fn.getFrameInfo();
-  FFI->setHasCalls(HasCalls);
-  FFI->setMaxCallFrameSize(MaxCallFrameSize);
-
-  // Now figure out which *callee saved* registers are modified by the current
-  // function, thus needing to be saved and restored in the prolog/epilog.
-  //
-  for (unsigned i = 0; CSRegs[i]; ++i) {
-    unsigned Reg = CSRegs[i];
-    if (ModifiedRegs[Reg]) {
-      RegsToSave.push_back(Reg);  // If modified register...
-    } else {
-      for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
-           *AliasSet; ++AliasSet) {  // Check alias registers too...
-        if (ModifiedRegs[*AliasSet]) {
-          RegsToSave.push_back(Reg);
-          break;
-        }
-      }
-    }
-  }
-  
-  // FIXME: should we sort the regs to save so that we always get the regs in
-  // the correct order?
-
-  // Now that we know which registers need to be saved and restored, allocate
-  // stack slots for them.
-  int Offset = 0;
-  for (unsigned i = 0, e = RegsToSave.size(); i != e; ++i) {
-    unsigned RegSize = RegInfo->getRegClass(RegsToSave[i])->getSize();
-    int FrameIdx;
-    
-    if (RegsToSave[i] == PPC::LR) {
-      FrameIdx = FFI->CreateFixedObject(RegSize, 8); // LR lives at +8
-    } else {
-      Offset -= RegSize;
-      FrameIdx = FFI->CreateFixedObject(RegSize, Offset);
-    }
-    StackSlots.push_back(FrameIdx);
-  }
-}
-
-
-/// saveCallerSavedRegisters -  Insert spill code for any caller saved registers
-/// that are modified in the function.
-///
-void PPCPEI::saveCallerSavedRegisters(MachineFunction &Fn) {
-  // Early exit if no caller saved registers are modified!
-  if (RegsToSave.empty())
-    return;   
-
-  const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
-
-  // Now that we have a stack slot for each register to be saved, insert spill
-  // code into the entry block...
-  MachineBasicBlock *MBB = Fn.begin();
-  MachineBasicBlock::iterator I = MBB->begin();
-  for (unsigned i = 0, e = RegsToSave.size(); i != e; ++i) {
-    const TargetRegisterClass *RC = RegInfo->getRegClass(RegsToSave[i]);
-    // Insert the spill to the stack frame...
-    RegInfo->storeRegToStackSlot(*MBB, I, RegsToSave[i], StackSlots[i], RC);
-  }
-
-  // Add code to restore the callee-save registers in each exiting block.
-  const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
-  for (MachineFunction::iterator FI = Fn.begin(), E = Fn.end(); FI != E; ++FI) {
-    // If last instruction is a return instruction, add an epilogue
-    if (!FI->empty() && TII.isReturn(FI->back().getOpcode())) {
-      MBB = FI;
-      I = MBB->end(); --I;
-
-      for (unsigned i = 0, e = RegsToSave.size(); i != e; ++i) {
-	const TargetRegisterClass *RC = RegInfo->getRegClass(RegsToSave[i]);
-	RegInfo->loadRegFromStackSlot(*MBB, I, RegsToSave[i],StackSlots[i], RC);
-	--I;  // Insert in reverse order
-      }
-    }
-  }
-}
-
-
-/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the
-/// abstract stack objects...
-///
-void PPCPEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
-  const TargetFrameInfo &TFI = *Fn.getTarget().getFrameInfo();
-  
-  bool StackGrowsDown =
-    TFI.getStackGrowthDirection() == TargetFrameInfo::StackGrowsDown;
- 
-  // Loop over all of the stack objects, assigning sequential addresses...
-  MachineFrameInfo *FFI = Fn.getFrameInfo();
-
-  unsigned StackAlignment = TFI.getStackAlignment();
-
-  // Start at the beginning of the local area.
-  // The Offset is the distance from the stack top in the direction
-  // of stack growth -- so it's always positive.
-  int Offset = TFI.getOffsetOfLocalArea();
-  if (StackGrowsDown)
-    Offset = -Offset;
-  assert(Offset >= 0 
-         && "Local area offset should be in direction of stack growth");
-
-  // If there are fixed sized objects that are preallocated in the local area,
-  // non-fixed objects can't be allocated right at the start of local area.
-  // We currently don't support filling in holes in between fixed sized objects, 
-  // so we adjust 'Offset' to point to the end of last fixed sized
-  // preallocated object.
-  for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
-    int FixedOff;
-    if (StackGrowsDown) {
-      // The maximum distance from the stack pointer is at lower address of
-      // the object -- which is given by offset. For down growing stack
-      // the offset is negative, so we negate the offset to get the distance.
-      FixedOff = -FFI->getObjectOffset(i);
-    } else {
-      // The maximum distance from the start pointer is at the upper 
-      // address of the object.
-      FixedOff = FFI->getObjectOffset(i) + FFI->getObjectSize(i);
-    }    
-    if (FixedOff > Offset) Offset = FixedOff;            
-  }
-
-  for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
-    // If stack grows down, we need to add size of find the lowest
-    // address of the object.
-    if (StackGrowsDown)
-      Offset += FFI->getObjectSize(i);
-
-    unsigned Align = FFI->getObjectAlignment(i);
-    assert(Align <= StackAlignment && "Cannot align stack object to higher "
-           "alignment boundary than the stack itself!");
-    Offset = (Offset+Align-1)/Align*Align;   // Adjust to Alignment boundary...
-    
-    if (StackGrowsDown) {
-      FFI->setObjectOffset(i, -Offset);        // Set the computed offset
-    } else {
-      FFI->setObjectOffset(i, Offset); 
-      Offset += FFI->getObjectSize(i);
-    }
-  }
-
-  // Set the final value of the stack pointer...
-  FFI->setStackSize(Offset);
-}
-
-
-/// insertPrologEpilogCode - Scan the function for modified caller saved
-/// registers, insert spill code for these caller saved registers, then add
-/// prolog and epilog code to the function.
-///
-void PPCPEI::insertPrologEpilogCode(MachineFunction &Fn) {
-  // Add prologue to the function...
-  Fn.getTarget().getRegisterInfo()->emitPrologue(Fn);
-
-  // Add epilogue to restore the callee-save registers in each exiting block
-  const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
-  for (MachineFunction::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) {
-    // If last instruction is a return instruction, add an epilogue
-    if (!I->empty() && TII.isReturn(I->back().getOpcode()))
-      Fn.getTarget().getRegisterInfo()->emitEpilogue(Fn, *I);
-  }
-}
-
-
-/// replaceFrameIndices - Replace all MO_FrameIndex operands with physical
-/// register references and actual offsets.
-///
-void PPCPEI::replaceFrameIndices(MachineFunction &Fn) {
-  if (!Fn.getFrameInfo()->hasStackObjects()) return; // Nothing to do?
-
-  const TargetMachine &TM = Fn.getTarget();
-  assert(TM.getRegisterInfo() && "TM::getRegisterInfo() must be implemented!");
-  const MRegisterInfo &MRI = *TM.getRegisterInfo();
-
-  for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB)
-    for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ++I)
-      for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
-	if (I->getOperand(i).isFrameIndex()) {
-	  // If this instruction has a FrameIndex operand, we need to use that
-	  // target machine register info object to eliminate it.
-	  MRI.eliminateFrameIndex(Fn, I);
-	  break;
-	}
-}