//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "pei"
#include "PrologEpilogInserter.h"
+#include "llvm/InlineAsm.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegisterInfo.h"
-#include "llvm/Target/TargetFrameInfo.h"
+#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/ADT/IndexedMap.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
#include <climits>
char PEI::ID = 0;
-static RegisterPass<PEI>
-X("prologepilog", "Prologue/Epilogue Insertion");
+INITIALIZE_PASS_BEGIN(PEI, "prologepilog",
+ "Prologue/Epilogue Insertion", false, false)
+INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
+INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
+INITIALIZE_PASS_END(PEI, "prologepilog",
+ "Prologue/Epilogue Insertion", false, false)
+
+STATISTIC(NumVirtualFrameRegs, "Number of virtual frame regs encountered");
+STATISTIC(NumScavengedRegs, "Number of frame index regs scavenged");
+STATISTIC(NumBytesStackSpace,
+ "Number of bytes used for stack in all functions");
/// createPrologEpilogCodeInserter - This function returns a pass that inserts
/// prolog and epilog code, and eliminates abstract frame references.
/// frame indexes with appropriate references.
///
bool PEI::runOnMachineFunction(MachineFunction &Fn) {
+ const Function* F = Fn.getFunction();
const TargetRegisterInfo *TRI = Fn.getTarget().getRegisterInfo();
+ const TargetFrameLowering *TFI = Fn.getTarget().getFrameLowering();
+
RS = TRI->requiresRegisterScavenging(Fn) ? new RegScavenger() : NULL;
+ FrameIndexVirtualScavenging = TRI->requiresFrameIndexScavenging(Fn);
- // Get MachineModuleInfo so that we can track the construction of the
- // frame.
- if (MachineModuleInfo *MMI = getAnalysisIfAvailable<MachineModuleInfo>())
- Fn.getFrameInfo()->setMachineModuleInfo(MMI);
+ // Calculate the MaxCallFrameSize and AdjustsStack variables for the
+ // function's frame information. Also eliminates call frame pseudo
+ // instructions.
+ calculateCallsInformation(Fn);
// Allow the target machine to make some adjustments to the function
// e.g. UsedPhysRegs before calculateCalleeSavedRegisters.
- TRI->processFunctionBeforeCalleeSavedScan(Fn, RS);
+ TFI->processFunctionBeforeCalleeSavedScan(Fn, RS);
- // Scan the function for modified callee saved registers and insert spill
- // code for any callee saved registers that are modified. Also calculate
- // the MaxCallFrameSize and HasCalls variables for the function's frame
- // information and eliminates call frame pseudo instructions.
+ // Scan the function for modified callee saved registers and insert spill code
+ // for any callee saved registers that are modified.
calculateCalleeSavedRegisters(Fn);
// Determine placement of CSR spill/restore code:
- // - with shrink wrapping, place spills and restores to tightly
+ // - With shrink wrapping, place spills and restores to tightly
// enclose regions in the Machine CFG of the function where
- // they are used. Without shrink wrapping
- // - default (no shrink wrapping), place all spills in the
+ // they are used.
+ // - Without shink wrapping (default), place all spills in the
// entry block, all restores in return blocks.
placeCSRSpillsAndRestores(Fn);
// Add the code to save and restore the callee saved registers
- insertCSRSpillsAndRestores(Fn);
+ if (!F->hasFnAttr(Attribute::Naked))
+ insertCSRSpillsAndRestores(Fn);
// Allow the target machine to make final modifications to the function
// before the frame layout is finalized.
- TRI->processFunctionBeforeFrameFinalized(Fn);
+ TFI->processFunctionBeforeFrameFinalized(Fn);
// Calculate actual frame offsets for all abstract stack objects...
calculateFrameObjectOffsets(Fn);
// Add prolog and epilog code to the function. This function is required
// to align the stack frame as necessary for any stack variables or
- // called functions. Because of this, calculateCalleeSavedRegisters
- // must be called before this function in order to set the HasCalls
+ // called functions. Because of this, calculateCalleeSavedRegisters()
+ // must be called before this function in order to set the AdjustsStack
// and MaxCallFrameSize variables.
- insertPrologEpilogCode(Fn);
+ if (!F->hasFnAttr(Attribute::Naked))
+ insertPrologEpilogCode(Fn);
// Replace all MO_FrameIndex operands with physical register references
// and actual offsets.
//
replaceFrameIndices(Fn);
+ // If register scavenging is needed, as we've enabled doing it as a
+ // post-pass, scavenge the virtual registers that frame index elimiation
+ // inserted.
+ if (TRI->requiresRegisterScavenging(Fn) && FrameIndexVirtualScavenging)
+ scavengeFrameVirtualRegs(Fn);
+
delete RS;
clearAllSets();
return true;
}
#endif
-/// calculateCalleeSavedRegisters - Scan the function for modified callee saved
-/// registers. Also calculate the MaxCallFrameSize and HasCalls variables for
-/// the function's frame information and eliminates call frame pseudo
-/// instructions.
-///
-void PEI::calculateCalleeSavedRegisters(MachineFunction &Fn) {
+/// calculateCallsInformation - Calculate the MaxCallFrameSize and AdjustsStack
+/// variables for the function's frame information and eliminate call frame
+/// pseudo instructions.
+void PEI::calculateCallsInformation(MachineFunction &Fn) {
const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
- const TargetFrameInfo *TFI = Fn.getTarget().getFrameInfo();
+ const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
+ const TargetFrameLowering *TFI = Fn.getTarget().getFrameLowering();
+ MachineFrameInfo *MFI = Fn.getFrameInfo();
- // Get the callee saved register list...
- const unsigned *CSRegs = RegInfo->getCalleeSavedRegs(&Fn);
+ unsigned MaxCallFrameSize = 0;
+ bool AdjustsStack = MFI->adjustsStack();
// Get the function call frame set-up and tear-down instruction opcode
- int FrameSetupOpcode = RegInfo->getCallFrameSetupOpcode();
- int FrameDestroyOpcode = RegInfo->getCallFrameDestroyOpcode();
-
- // These are used to keep track the callee-save area. Initialize them.
- MinCSFrameIndex = INT_MAX;
- MaxCSFrameIndex = 0;
+ int FrameSetupOpcode = TII.getCallFrameSetupOpcode();
+ int FrameDestroyOpcode = TII.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)
+ // Early exit for targets which have no call frame setup/destroy pseudo
+ // instructions.
+ if (FrameSetupOpcode == -1 && FrameDestroyOpcode == -1)
return;
- unsigned MaxCallFrameSize = 0;
- bool HasCalls = false;
-
std::vector<MachineBasicBlock::iterator> FrameSDOps;
for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB)
for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ++I)
" instructions should have a single immediate argument!");
unsigned Size = I->getOperand(0).getImm();
if (Size > MaxCallFrameSize) MaxCallFrameSize = Size;
- HasCalls = true;
+ AdjustsStack = true;
FrameSDOps.push_back(I);
+ } else if (I->isInlineAsm()) {
+ // Some inline asm's need a stack frame, as indicated by operand 1.
+ unsigned ExtraInfo = I->getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
+ if (ExtraInfo & InlineAsm::Extra_IsAlignStack)
+ AdjustsStack = true;
}
- MachineFrameInfo *FFI = Fn.getFrameInfo();
- FFI->setHasCalls(HasCalls);
- FFI->setMaxCallFrameSize(MaxCallFrameSize);
+ MFI->setAdjustsStack(AdjustsStack);
+ MFI->setMaxCallFrameSize(MaxCallFrameSize);
+
+ for (std::vector<MachineBasicBlock::iterator>::iterator
+ i = FrameSDOps.begin(), e = FrameSDOps.end(); i != e; ++i) {
+ MachineBasicBlock::iterator I = *i;
- for (unsigned i = 0, e = FrameSDOps.size(); i != e; ++i) {
- MachineBasicBlock::iterator I = FrameSDOps[i];
- // If call frames are not being included as part of the stack frame,
- // and there is no dynamic allocation (therefore referencing frame slots
- // off sp), leave the pseudo ops alone. We'll eliminate them later.
- if (RegInfo->hasReservedCallFrame(Fn) || RegInfo->hasFP(Fn))
+ // If call frames are not being included as part of the stack frame, and
+ // the target doesn't indicate otherwise, remove the call frame pseudos
+ // here. The sub/add sp instruction pairs are still inserted, but we don't
+ // need to track the SP adjustment for frame index elimination.
+ if (TFI->canSimplifyCallFramePseudos(Fn))
RegInfo->eliminateCallFramePseudoInstr(Fn, *I->getParent(), I);
}
+}
+
+
+/// calculateCalleeSavedRegisters - Scan the function for modified callee saved
+/// registers.
+void PEI::calculateCalleeSavedRegisters(MachineFunction &Fn) {
+ const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
+ const TargetFrameLowering *TFI = Fn.getTarget().getFrameLowering();
+ MachineFrameInfo *MFI = Fn.getFrameInfo();
+
+ // Get the callee saved register list...
+ const unsigned *CSRegs = RegInfo->getCalleeSavedRegs(&Fn);
+
+ // These are used to keep track the callee-save area. Initialize them.
+ MinCSFrameIndex = INT_MAX;
+ MaxCSFrameIndex = 0;
+
+ // Early exit for targets which have no callee saved registers.
+ if (CSRegs == 0 || CSRegs[0] == 0)
+ return;
+
+ // In Naked functions we aren't going to save any registers.
+ if (Fn.getFunction()->hasFnAttr(Attribute::Naked))
+ return;
- // Now figure out which *callee saved* registers are modified by the current
- // function, thus needing to be saved and restored in the prolog/epilog.
- //
- const TargetRegisterClass* const *CSRegClasses =
- RegInfo->getCalleeSavedRegClasses(&Fn);
std::vector<CalleeSavedInfo> CSI;
for (unsigned i = 0; CSRegs[i]; ++i) {
unsigned Reg = CSRegs[i];
if (Fn.getRegInfo().isPhysRegUsed(Reg)) {
- // If the reg is modified, save it!
- CSI.push_back(CalleeSavedInfo(Reg, CSRegClasses[i]));
+ // If the reg is modified, save it!
+ CSI.push_back(CalleeSavedInfo(Reg));
} else {
for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
*AliasSet; ++AliasSet) { // Check alias registers too.
if (Fn.getRegInfo().isPhysRegUsed(*AliasSet)) {
- CSI.push_back(CalleeSavedInfo(Reg, CSRegClasses[i]));
+ CSI.push_back(CalleeSavedInfo(Reg));
break;
}
}
return; // Early exit if no callee saved registers are modified!
unsigned NumFixedSpillSlots;
- const std::pair<unsigned,int> *FixedSpillSlots =
+ const TargetFrameLowering::SpillSlot *FixedSpillSlots =
TFI->getCalleeSavedSpillSlots(NumFixedSpillSlots);
// Now that we know which registers need to be saved and restored, allocate
// stack slots for them.
- for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
- unsigned Reg = CSI[i].getReg();
- const TargetRegisterClass *RC = CSI[i].getRegClass();
+ for (std::vector<CalleeSavedInfo>::iterator
+ I = CSI.begin(), E = CSI.end(); I != E; ++I) {
+ unsigned Reg = I->getReg();
+ const TargetRegisterClass *RC = RegInfo->getMinimalPhysRegClass(Reg);
+
+ int FrameIdx;
+ if (RegInfo->hasReservedSpillSlot(Fn, Reg, FrameIdx)) {
+ I->setFrameIdx(FrameIdx);
+ continue;
+ }
// Check to see if this physreg must be spilled to a particular stack slot
// on this target.
- const std::pair<unsigned,int> *FixedSlot = FixedSpillSlots;
+ const TargetFrameLowering::SpillSlot *FixedSlot = FixedSpillSlots;
while (FixedSlot != FixedSpillSlots+NumFixedSpillSlots &&
- FixedSlot->first != Reg)
+ FixedSlot->Reg != Reg)
++FixedSlot;
- int FrameIdx;
- if (FixedSlot == FixedSpillSlots+NumFixedSpillSlots) {
+ if (FixedSlot == FixedSpillSlots + NumFixedSpillSlots) {
// Nope, just spill it anywhere convenient.
unsigned Align = RC->getAlignment();
unsigned StackAlign = TFI->getStackAlignment();
- // We may not be able to sastify the desired alignment specification of
- // the TargetRegisterClass if the stack alignment is smaller.
- // Use the min.
+
+ // We may not be able to satisfy the desired alignment specification of
+ // the TargetRegisterClass if the stack alignment is smaller. Use the
+ // min.
Align = std::min(Align, StackAlign);
- FrameIdx = FFI->CreateStackObject(RC->getSize(), Align);
+ FrameIdx = MFI->CreateStackObject(RC->getSize(), Align, true);
if ((unsigned)FrameIdx < MinCSFrameIndex) MinCSFrameIndex = FrameIdx;
if ((unsigned)FrameIdx > MaxCSFrameIndex) MaxCSFrameIndex = FrameIdx;
} else {
// Spill it to the stack where we must.
- FrameIdx = FFI->CreateFixedObject(RC->getSize(), FixedSlot->second);
+ FrameIdx = MFI->CreateFixedObject(RC->getSize(), FixedSlot->Offset, true);
}
- CSI[i].setFrameIdx(FrameIdx);
+
+ I->setFrameIdx(FrameIdx);
}
- FFI->setCalleeSavedInfo(CSI);
+ MFI->setCalleeSavedInfo(CSI);
}
/// insertCSRSpillsAndRestores - Insert spill and restore code for
///
void PEI::insertCSRSpillsAndRestores(MachineFunction &Fn) {
// Get callee saved register information.
- MachineFrameInfo *FFI = Fn.getFrameInfo();
- const std::vector<CalleeSavedInfo> &CSI = FFI->getCalleeSavedInfo();
+ MachineFrameInfo *MFI = Fn.getFrameInfo();
+ const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+
+ MFI->setCalleeSavedInfoValid(true);
// Early exit if no callee saved registers are modified!
if (CSI.empty())
return;
const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
+ const TargetFrameLowering *TFI = Fn.getTarget().getFrameLowering();
+ const TargetRegisterInfo *TRI = Fn.getTarget().getRegisterInfo();
MachineBasicBlock::iterator I;
if (! ShrinkWrapThisFunction) {
// Spill using target interface.
I = EntryBlock->begin();
- if (!TII.spillCalleeSavedRegisters(*EntryBlock, I, CSI)) {
+ if (!TFI->spillCalleeSavedRegisters(*EntryBlock, I, CSI, TRI)) {
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
// Add the callee-saved register as live-in.
// It's killed at the spill.
EntryBlock->addLiveIn(CSI[i].getReg());
// Insert the spill to the stack frame.
- TII.storeRegToStackSlot(*EntryBlock, I, CSI[i].getReg(), true,
- CSI[i].getFrameIdx(), CSI[i].getRegClass());
+ unsigned Reg = CSI[i].getReg();
+ const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
+ TII.storeRegToStackSlot(*EntryBlock, I, Reg, true,
+ CSI[i].getFrameIdx(), RC, TRI);
}
}
--BeforeI;
// Restore all registers immediately before the return and any
- // terminators that preceed it.
- if (!TII.restoreCalleeSavedRegisters(*MBB, I, CSI)) {
+ // terminators that precede it.
+ if (!TFI->restoreCalleeSavedRegisters(*MBB, I, CSI, TRI)) {
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
- TII.loadRegFromStackSlot(*MBB, I, CSI[i].getReg(),
+ unsigned Reg = CSI[i].getReg();
+ const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
+ TII.loadRegFromStackSlot(*MBB, I, Reg,
CSI[i].getFrameIdx(),
- CSI[i].getRegClass());
+ RC, TRI);
assert(I != MBB->begin() &&
"loadRegFromStackSlot didn't insert any code!");
// Insert in reverse order. loadRegFromStackSlot can insert
MBB->addLiveIn(blockCSI[i].getReg());
// Insert the spill to the stack frame.
- TII.storeRegToStackSlot(*MBB, I, blockCSI[i].getReg(),
+ unsigned Reg = blockCSI[i].getReg();
+ const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
+ TII.storeRegToStackSlot(*MBB, I, Reg,
true,
blockCSI[i].getFrameIdx(),
- blockCSI[i].getRegClass());
+ RC, TRI);
}
}
--BeforeI;
// Restore all registers immediately before the return and any
- // terminators that preceed it.
+ // terminators that precede it.
for (unsigned i = 0, e = blockCSI.size(); i != e; ++i) {
- TII.loadRegFromStackSlot(*MBB, I, blockCSI[i].getReg(),
+ unsigned Reg = blockCSI[i].getReg();
+ const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
+ TII.loadRegFromStackSlot(*MBB, I, Reg,
blockCSI[i].getFrameIdx(),
- blockCSI[i].getRegClass());
+ RC, TRI);
assert(I != MBB->begin() &&
"loadRegFromStackSlot didn't insert any code!");
// Insert in reverse order. loadRegFromStackSlot can insert
/// AdjustStackOffset - Helper function used to adjust the stack frame offset.
static inline void
-AdjustStackOffset(MachineFrameInfo *FFI, int FrameIdx,
+AdjustStackOffset(MachineFrameInfo *MFI, int FrameIdx,
bool StackGrowsDown, int64_t &Offset,
unsigned &MaxAlign) {
- // If stack grows down, we need to add size of find the lowest address of the
- // object.
+ // If the stack grows down, add the object size to find the lowest address.
if (StackGrowsDown)
- Offset += FFI->getObjectSize(FrameIdx);
+ Offset += MFI->getObjectSize(FrameIdx);
- unsigned Align = FFI->getObjectAlignment(FrameIdx);
+ unsigned Align = MFI->getObjectAlignment(FrameIdx);
// If the alignment of this object is greater than that of the stack, then
// increase the stack alignment to match.
Offset = (Offset + Align - 1) / Align * Align;
if (StackGrowsDown) {
- FFI->setObjectOffset(FrameIdx, -Offset); // Set the computed offset
+ DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") at SP[" << -Offset << "]\n");
+ MFI->setObjectOffset(FrameIdx, -Offset); // Set the computed offset
} else {
- FFI->setObjectOffset(FrameIdx, Offset);
- Offset += FFI->getObjectSize(FrameIdx);
+ DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") at SP[" << Offset << "]\n");
+ MFI->setObjectOffset(FrameIdx, Offset);
+ Offset += MFI->getObjectSize(FrameIdx);
}
}
/// abstract stack objects.
///
void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
- const TargetFrameInfo &TFI = *Fn.getTarget().getFrameInfo();
+ const TargetFrameLowering &TFI = *Fn.getTarget().getFrameLowering();
bool StackGrowsDown =
- TFI.getStackGrowthDirection() == TargetFrameInfo::StackGrowsDown;
+ TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;
// Loop over all of the stack objects, assigning sequential addresses...
- MachineFrameInfo *FFI = Fn.getFrameInfo();
-
- unsigned MaxAlign = FFI->getMaxAlignment();
+ MachineFrameInfo *MFI = Fn.getFrameInfo();
// 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 nonnegative.
- int64_t Offset = TFI.getOffsetOfLocalArea();
+ int LocalAreaOffset = TFI.getOffsetOfLocalArea();
if (StackGrowsDown)
- Offset = -Offset;
- assert(Offset >= 0
+ LocalAreaOffset = -LocalAreaOffset;
+ assert(LocalAreaOffset >= 0
&& "Local area offset should be in direction of stack growth");
+ int64_t Offset = LocalAreaOffset;
// 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) {
+ for (int i = MFI->getObjectIndexBegin(); i != 0; ++i) {
int64_t 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);
+ FixedOff = -MFI->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);
+ FixedOff = MFI->getObjectOffset(i) + MFI->getObjectSize(i);
}
if (FixedOff > Offset) Offset = FixedOff;
}
// callee saved registers.
if (StackGrowsDown) {
for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) {
- // If stack grows down, we need to add size of find the lowest
+ // If the stack grows down, we need to add the size to find the lowest
// address of the object.
- Offset += FFI->getObjectSize(i);
+ Offset += MFI->getObjectSize(i);
- unsigned Align = FFI->getObjectAlignment(i);
- // If the alignment of this object is greater than that of the stack,
- // then increase the stack alignment to match.
- MaxAlign = std::max(MaxAlign, Align);
+ unsigned Align = MFI->getObjectAlignment(i);
// Adjust to alignment boundary
Offset = (Offset+Align-1)/Align*Align;
- FFI->setObjectOffset(i, -Offset); // Set the computed offset
+ MFI->setObjectOffset(i, -Offset); // Set the computed offset
}
} else {
int MaxCSFI = MaxCSFrameIndex, MinCSFI = MinCSFrameIndex;
for (int i = MaxCSFI; i >= MinCSFI ; --i) {
- unsigned Align = FFI->getObjectAlignment(i);
- // If the alignment of this object is greater than that of the stack,
- // then increase the stack alignment to match.
- MaxAlign = std::max(MaxAlign, Align);
+ unsigned Align = MFI->getObjectAlignment(i);
// Adjust to alignment boundary
Offset = (Offset+Align-1)/Align*Align;
- FFI->setObjectOffset(i, Offset);
- Offset += FFI->getObjectSize(i);
+ MFI->setObjectOffset(i, Offset);
+ Offset += MFI->getObjectSize(i);
}
}
+ unsigned MaxAlign = MFI->getMaxAlignment();
+
// Make sure the special register scavenging spill slot is closest to the
// frame pointer if a frame pointer is required.
const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
- if (RS && RegInfo->hasFP(Fn)) {
+ if (RS && TFI.hasFP(Fn) && RegInfo->useFPForScavengingIndex(Fn) &&
+ !RegInfo->needsStackRealignment(Fn)) {
int SFI = RS->getScavengingFrameIndex();
if (SFI >= 0)
- AdjustStackOffset(FFI, SFI, StackGrowsDown, Offset, MaxAlign);
+ AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
+ }
+
+ // FIXME: Once this is working, then enable flag will change to a target
+ // check for whether the frame is large enough to want to use virtual
+ // frame index registers. Functions which don't want/need this optimization
+ // will continue to use the existing code path.
+ if (MFI->getUseLocalStackAllocationBlock()) {
+ unsigned Align = MFI->getLocalFrameMaxAlign();
+
+ // Adjust to alignment boundary.
+ Offset = (Offset + Align - 1) / Align * Align;
+
+ DEBUG(dbgs() << "Local frame base offset: " << Offset << "\n");
+
+ // Resolve offsets for objects in the local block.
+ for (unsigned i = 0, e = MFI->getLocalFrameObjectCount(); i != e; ++i) {
+ std::pair<int, int64_t> Entry = MFI->getLocalFrameObjectMap(i);
+ int64_t FIOffset = (StackGrowsDown ? -Offset : Offset) + Entry.second;
+ DEBUG(dbgs() << "alloc FI(" << Entry.first << ") at SP[" <<
+ FIOffset << "]\n");
+ MFI->setObjectOffset(Entry.first, FIOffset);
+ }
+ // Allocate the local block
+ Offset += MFI->getLocalFrameSize();
+
+ MaxAlign = std::max(Align, MaxAlign);
}
// Make sure that the stack protector comes before the local variables on the
// stack.
- if (FFI->getStackProtectorIndex() >= 0)
- AdjustStackOffset(FFI, FFI->getStackProtectorIndex(), StackGrowsDown,
+ SmallSet<int, 16> LargeStackObjs;
+ if (MFI->getStackProtectorIndex() >= 0) {
+ AdjustStackOffset(MFI, MFI->getStackProtectorIndex(), StackGrowsDown,
Offset, MaxAlign);
+ // Assign large stack objects first.
+ for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
+ if (MFI->isObjectPreAllocated(i) &&
+ MFI->getUseLocalStackAllocationBlock())
+ continue;
+ if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
+ continue;
+ if (RS && (int)i == RS->getScavengingFrameIndex())
+ continue;
+ if (MFI->isDeadObjectIndex(i))
+ continue;
+ if (MFI->getStackProtectorIndex() == (int)i)
+ continue;
+ if (!MFI->MayNeedStackProtector(i))
+ continue;
+
+ AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign);
+ LargeStackObjs.insert(i);
+ }
+ }
+
// Then assign frame offsets to stack objects that are not used to spill
// callee saved registers.
- for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
+ for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
+ if (MFI->isObjectPreAllocated(i) &&
+ MFI->getUseLocalStackAllocationBlock())
+ continue;
if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
continue;
if (RS && (int)i == RS->getScavengingFrameIndex())
continue;
- if (FFI->isDeadObjectIndex(i))
+ if (MFI->isDeadObjectIndex(i))
continue;
- if (FFI->getStackProtectorIndex() == (int)i)
+ if (MFI->getStackProtectorIndex() == (int)i)
+ continue;
+ if (LargeStackObjs.count(i))
continue;
- AdjustStackOffset(FFI, i, StackGrowsDown, Offset, MaxAlign);
+ AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign);
}
// Make sure the special register scavenging spill slot is closest to the
// stack pointer.
- if (RS && !RegInfo->hasFP(Fn)) {
+ if (RS && (!TFI.hasFP(Fn) || RegInfo->needsStackRealignment(Fn) ||
+ !RegInfo->useFPForScavengingIndex(Fn))) {
int SFI = RS->getScavengingFrameIndex();
if (SFI >= 0)
- AdjustStackOffset(FFI, SFI, StackGrowsDown, Offset, MaxAlign);
+ AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
}
- // Round up the size to a multiple of the alignment, but only if there are
- // calls or alloca's in the function. This ensures that any calls to
- // subroutines have their stack frames suitable aligned.
- // Also do this if we need runtime alignment of the stack. In this case
- // offsets will be relative to SP not FP; round up the stack size so this
- // works.
- if (!RegInfo->targetHandlesStackFrameRounding() &&
- (FFI->hasCalls() || FFI->hasVarSizedObjects() ||
- (RegInfo->needsStackRealignment(Fn) &&
- FFI->getObjectIndexEnd() != 0))) {
+ if (!TFI.targetHandlesStackFrameRounding()) {
// If we have reserved argument space for call sites in the function
// immediately on entry to the current function, count it as part of the
// overall stack size.
- if (RegInfo->hasReservedCallFrame(Fn))
- Offset += FFI->getMaxCallFrameSize();
-
- unsigned AlignMask = std::max(TFI.getStackAlignment(),MaxAlign) - 1;
+ if (MFI->adjustsStack() && TFI.hasReservedCallFrame(Fn))
+ Offset += MFI->getMaxCallFrameSize();
+
+ // Round up the size to a multiple of the alignment. If the function has
+ // any calls or alloca's, align to the target's StackAlignment value to
+ // ensure that the callee's frame or the alloca data is suitably aligned;
+ // otherwise, for leaf functions, align to the TransientStackAlignment
+ // value.
+ unsigned StackAlign;
+ if (MFI->adjustsStack() || MFI->hasVarSizedObjects() ||
+ (RegInfo->needsStackRealignment(Fn) && MFI->getObjectIndexEnd() != 0))
+ StackAlign = TFI.getStackAlignment();
+ else
+ StackAlign = TFI.getTransientStackAlignment();
+
+ // If the frame pointer is eliminated, all frame offsets will be relative to
+ // SP not FP. Align to MaxAlign so this works.
+ StackAlign = std::max(StackAlign, MaxAlign);
+ unsigned AlignMask = StackAlign - 1;
Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
}
// Update frame info to pretend that this is part of the stack...
- FFI->setStackSize(Offset+TFI.getOffsetOfLocalArea());
-
- // Remember the required stack alignment in case targets need it to perform
- // dynamic stack alignment.
- FFI->setMaxAlignment(MaxAlign);
+ int64_t StackSize = Offset - LocalAreaOffset;
+ MFI->setStackSize(StackSize);
+ NumBytesStackSpace += StackSize;
}
-
/// insertPrologEpilogCode - Scan the function for modified callee saved
/// registers, insert spill code for these callee saved registers, then add
/// prolog and epilog code to the function.
///
void PEI::insertPrologEpilogCode(MachineFunction &Fn) {
- const TargetRegisterInfo *TRI = Fn.getTarget().getRegisterInfo();
+ const TargetFrameLowering &TFI = *Fn.getTarget().getFrameLowering();
// Add prologue to the function...
- TRI->emitPrologue(Fn);
+ TFI.emitPrologue(Fn);
// Add epilogue to restore the callee-save registers in each exiting block
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() && I->back().getDesc().isReturn())
- TRI->emitEpilogue(Fn, *I);
+ TFI.emitEpilogue(Fn, *I);
}
-}
+ // Emit additional code that is required to support segmented stacks, if
+ // we've been asked for it. This, when linked with a runtime with support
+ // for segmented stacks (libgcc is one), will result in allocating stack
+ // space in small chunks instead of one large contiguous block.
+ if (EnableSegmentedStacks)
+ TFI.adjustForSegmentedStacks(Fn);
+}
/// replaceFrameIndices - Replace all MO_FrameIndex operands with physical
/// register references and actual offsets.
const TargetMachine &TM = Fn.getTarget();
assert(TM.getRegisterInfo() && "TM::getRegisterInfo() must be implemented!");
+ const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
const TargetRegisterInfo &TRI = *TM.getRegisterInfo();
- const TargetFrameInfo *TFI = TM.getFrameInfo();
+ const TargetFrameLowering *TFI = TM.getFrameLowering();
bool StackGrowsDown =
- TFI->getStackGrowthDirection() == TargetFrameInfo::StackGrowsDown;
- int FrameSetupOpcode = TRI.getCallFrameSetupOpcode();
- int FrameDestroyOpcode = TRI.getCallFrameDestroyOpcode();
+ TFI->getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;
+ int FrameSetupOpcode = TII.getCallFrameSetupOpcode();
+ int FrameDestroyOpcode = TII.getCallFrameDestroyOpcode();
for (MachineFunction::iterator BB = Fn.begin(),
E = Fn.end(); BB != E; ++BB) {
+#ifndef NDEBUG
+ int SPAdjCount = 0; // frame setup / destroy count.
+#endif
int SPAdj = 0; // SP offset due to call frame setup / destroy.
- if (RS) RS->enterBasicBlock(BB);
+ if (RS && !FrameIndexVirtualScavenging) RS->enterBasicBlock(BB);
for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ) {
- if (I->getOpcode() == TargetInstrInfo::DECLARE) {
- // Ignore it.
- ++I;
- continue;
- }
if (I->getOpcode() == FrameSetupOpcode ||
I->getOpcode() == FrameDestroyOpcode) {
+#ifndef NDEBUG
+ // Track whether we see even pairs of them
+ SPAdjCount += I->getOpcode() == FrameSetupOpcode ? 1 : -1;
+#endif
// Remember how much SP has been adjusted to create the call
// frame.
int Size = I->getOperand(0).getImm();
if (PrevI == BB->end())
I = BB->begin(); // The replaced instr was the first in the block.
else
- I = next(PrevI);
+ I = llvm::next(PrevI);
continue;
}
// If this instruction has a FrameIndex operand, we need to
// use that target machine register info object to eliminate
// it.
-
- TRI.eliminateFrameIndex(MI, SPAdj, RS);
+ TRI.eliminateFrameIndex(MI, SPAdj,
+ FrameIndexVirtualScavenging ? NULL : RS);
// Reset the iterator if we were at the beginning of the BB.
if (AtBeginning) {
if (DoIncr && I != BB->end()) ++I;
// Update register states.
- if (RS && MI) RS->forward(MI);
+ if (RS && !FrameIndexVirtualScavenging && MI) RS->forward(MI);
}
- assert(SPAdj == 0 && "Unbalanced call frame setup / destroy pairs?");
+ // If we have evenly matched pairs of frame setup / destroy instructions,
+ // make sure the adjustments come out to zero. If we don't have matched
+ // pairs, we can't be sure the missing bit isn't in another basic block
+ // due to a custom inserter playing tricks, so just asserting SPAdj==0
+ // isn't sufficient. See tMOVCC on Thumb1, for example.
+ assert((SPAdjCount || SPAdj == 0) &&
+ "Unbalanced call frame setup / destroy pairs?");
}
}
+/// scavengeFrameVirtualRegs - Replace all frame index virtual registers
+/// with physical registers. Use the register scavenger to find an
+/// appropriate register to use.
+void PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) {
+ // Run through the instructions and find any virtual registers.
+ for (MachineFunction::iterator BB = Fn.begin(),
+ E = Fn.end(); BB != E; ++BB) {
+ RS->enterBasicBlock(BB);
+
+ unsigned VirtReg = 0;
+ unsigned ScratchReg = 0;
+ int SPAdj = 0;
+
+ // The instruction stream may change in the loop, so check BB->end()
+ // directly.
+ for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ) {
+ MachineInstr *MI = I;
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ if (MI->getOperand(i).isReg()) {
+ MachineOperand &MO = MI->getOperand(i);
+ unsigned Reg = MO.getReg();
+ if (Reg == 0)
+ continue;
+ if (!TargetRegisterInfo::isVirtualRegister(Reg))
+ continue;
+
+ ++NumVirtualFrameRegs;
+
+ // Have we already allocated a scratch register for this virtual?
+ if (Reg != VirtReg) {
+ // When we first encounter a new virtual register, it
+ // must be a definition.
+ assert(MI->getOperand(i).isDef() &&
+ "frame index virtual missing def!");
+ // Scavenge a new scratch register
+ VirtReg = Reg;
+ const TargetRegisterClass *RC = Fn.getRegInfo().getRegClass(Reg);
+ ScratchReg = RS->scavengeRegister(RC, I, SPAdj);
+ ++NumScavengedRegs;
+ }
+ // Replace this reference to the virtual register with the
+ // scratch register.
+ assert (ScratchReg && "Missing scratch register!");
+ MI->getOperand(i).setReg(ScratchReg);
+
+ }
+ }
+ RS->forward(I);
+ ++I;
+ }
+ }
+}
projects / oota-llvm.git / blobdiff