[llvm-commits] CVS: llvm/lib/Target/PowerPC/PowerPCPEI.cpp
Chris Lattner
lattner at cs.uiuc.edu
Fri Aug 6 00:45:50 PDT 2004
Changes in directory llvm/lib/Target/PowerPC:
PowerPCPEI.cpp updated: 1.1 -> 1.2
---
Log message:
Now without stinky dos newlines!
---
Diffs of the changes: (+326 -326)
Index: llvm/lib/Target/PowerPC/PowerPCPEI.cpp
diff -u llvm/lib/Target/PowerPC/PowerPCPEI.cpp:1.1 llvm/lib/Target/PowerPC/PowerPCPEI.cpp:1.2
--- llvm/lib/Target/PowerPC/PowerPCPEI.cpp:1.1 Fri Aug 6 01:58:50 2004
+++ llvm/lib/Target/PowerPC/PowerPCPEI.cpp Fri Aug 6 02:45:37 2004
@@ -1,326 +1,326 @@
-//===-- 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] == PPC32::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;
- }
-}
+//===-- 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] == PPC32::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;
+ }
+}
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