#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/TargetFrameLowering.h"
#include "llvm/Target/TargetInstrInfo.h"
using namespace llvm;
char PEI::ID = 0;
+char &llvm::PrologEpilogCodeInserterID = PEI::ID;
INITIALIZE_PASS_BEGIN(PEI, "prologepilog",
"Prologue/Epilogue Insertion", false, false)
INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
+INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
INITIALIZE_PASS_END(PEI, "prologepilog",
- "Prologue/Epilogue Insertion", false, false)
+ "Prologue/Epilogue Insertion & Frame Finalization",
+ false, false)
STATISTIC(NumVirtualFrameRegs, "Number of virtual frame regs encountered");
STATISTIC(NumScavengedRegs, "Number of frame index regs scavenged");
-
-/// createPrologEpilogCodeInserter - This function returns a pass that inserts
-/// prolog and epilog code, and eliminates abstract frame references.
-///
-FunctionPass *llvm::createPrologEpilogCodeInserter() { return new PEI(); }
+STATISTIC(NumBytesStackSpace,
+ "Number of bytes used for stack in all functions");
/// runOnMachineFunction - Insert prolog/epilog code and replace abstract
/// frame indexes with appropriate references.
const TargetRegisterInfo *TRI = Fn.getTarget().getRegisterInfo();
const TargetFrameLowering *TFI = Fn.getTarget().getFrameLowering();
+ assert(!Fn.getRegInfo().getNumVirtRegs() && "Regalloc must assign all vregs");
+
RS = TRI->requiresRegisterScavenging(Fn) ? new RegScavenger() : NULL;
FrameIndexVirtualScavenging = TRI->requiresFrameIndexScavenging(Fn);
if (TRI->requiresRegisterScavenging(Fn) && FrameIndexVirtualScavenging)
scavengeFrameVirtualRegs(Fn);
+ // Clear any vregs created by virtual scavenging.
+ Fn.getRegInfo().clearVirtRegs();
+
delete RS;
clearAllSets();
return true;
/// pseudo instructions.
void PEI::calculateCallsInformation(MachineFunction &Fn) {
const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
+ const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
const TargetFrameLowering *TFI = Fn.getTarget().getFrameLowering();
MachineFrameInfo *MFI = Fn.getFrameInfo();
bool AdjustsStack = MFI->adjustsStack();
// Get the function call frame set-up and tear-down instruction opcode
- int FrameSetupOpcode = RegInfo->getCallFrameSetupOpcode();
- int FrameDestroyOpcode = RegInfo->getCallFrameDestroyOpcode();
+ int FrameSetupOpcode = TII.getCallFrameSetupOpcode();
+ int FrameDestroyOpcode = TII.getCallFrameDestroyOpcode();
// Early exit for targets which have no call frame setup/destroy pseudo
// instructions.
MachineFrameInfo *MFI = Fn.getFrameInfo();
// Get the callee saved register list...
- const unsigned *CSRegs = RegInfo->getCalleeSavedRegs(&Fn);
+ const uint16_t *CSRegs = RegInfo->getCalleeSavedRegs(&Fn);
// These are used to keep track the callee-save area. Initialize them.
MinCSFrameIndex = INT_MAX;
std::vector<CalleeSavedInfo> CSI;
for (unsigned i = 0; CSRegs[i]; ++i) {
unsigned Reg = CSRegs[i];
- if (Fn.getRegInfo().isPhysRegUsed(Reg)) {
+ if (Fn.getRegInfo().isPhysRegOrOverlapUsed(Reg)) {
// 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));
- break;
- }
- }
}
}
// Skip over all terminator instructions, which are part of the return
// sequence.
MachineBasicBlock::iterator I2 = I;
- while (I2 != MBB->begin() && (--I2)->getDesc().isTerminator())
+ while (I2 != MBB->begin() && (--I2)->isTerminator())
I = I2;
bool AtStart = I == MBB->begin();
--BeforeI;
// Restore all registers immediately before the return and any
- // terminators that preceed it.
+ // terminators that precede it.
if (!TFI->restoreCalleeSavedRegisters(*MBB, I, CSI, TRI)) {
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned Reg = CSI[i].getReg();
// Skip over all terminator instructions, which are part of the
// return sequence.
- if (! I->getDesc().isTerminator()) {
+ if (! I->isTerminator()) {
++I;
} else {
MachineBasicBlock::iterator I2 = I;
- while (I2 != MBB->begin() && (--I2)->getDesc().isTerminator())
+ while (I2 != MBB->begin() && (--I2)->isTerminator())
I = I2;
}
}
--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) {
unsigned Reg = blockCSI[i].getReg();
const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
// 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 && TFI.hasFP(Fn) && !RegInfo->needsStackRealignment(Fn)) {
+ if (RS && TFI.hasFP(Fn) && RegInfo->useFPForScavengingIndex(Fn) &&
+ !RegInfo->needsStackRealignment(Fn)) {
int SFI = RS->getScavengingFrameIndex();
if (SFI >= 0)
AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
// Make sure the special register scavenging spill slot is closest to the
// stack pointer.
- if (RS && (!TFI.hasFP(Fn) || RegInfo->needsStackRealignment(Fn))) {
+ if (RS && (!TFI.hasFP(Fn) || RegInfo->needsStackRealignment(Fn) ||
+ !RegInfo->useFPForScavengingIndex(Fn))) {
int SFI = RS->getScavengingFrameIndex();
if (SFI >= 0)
AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
}
// Update frame info to pretend that this is part of the stack...
- MFI->setStackSize(Offset - LocalAreaOffset);
+ int64_t StackSize = Offset - LocalAreaOffset;
+ MFI->setStackSize(StackSize);
+ NumBytesStackSpace += StackSize;
}
/// insertPrologEpilogCode - Scan the function for modified callee saved
// 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())
+ if (!I->empty() && I->back().isReturn())
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 (Fn.getTarget().Options.EnableSegmentedStacks)
+ TFI.adjustForSegmentedStacks(Fn);
}
/// replaceFrameIndices - Replace all MO_FrameIndex operands with physical
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 TargetFrameLowering *TFI = TM.getFrameLowering();
bool StackGrowsDown =
TFI->getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;
- int FrameSetupOpcode = TRI.getCallFrameSetupOpcode();
- int FrameDestroyOpcode = TRI.getCallFrameDestroyOpcode();
+ int FrameSetupOpcode = TII.getCallFrameSetupOpcode();
+ int FrameDestroyOpcode = TII.getCallFrameDestroyOpcode();
for (MachineFunction::iterator BB = Fn.begin(),
E = Fn.end(); BB != E; ++BB) {
/// scavengeFrameVirtualRegs - Replace all frame index virtual registers
/// with physical registers. Use the register scavenger to find an
/// appropriate register to use.
+///
+/// FIXME: Iterating over the instruction stream is unnecessary. We can simply
+/// iterate over the vreg use list, which at this point only contains machine
+/// operands for which eliminateFrameIndex need a new scratch reg.
void PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) {
// Run through the instructions and find any virtual registers.
for (MachineFunction::iterator BB = Fn.begin(),
// directly.
for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ) {
MachineInstr *MI = I;
- bool DoIncr = true;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
if (MI->getOperand(i).isReg()) {
MachineOperand &MO = MI->getOperand(i);
}
}
- if (DoIncr) {
- RS->forward(I);
- ++I;
- }
+ RS->forward(I);
+ ++I;
}
}
}
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