#include "llvm/Target/MRegisterInfo.h"
#include "llvm/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetInstrInfo.h"
-
-namespace llvm {
+using namespace llvm;
namespace {
struct PEI : public MachineFunctionPass {
/// createPrologEpilogCodeInserter - This function returns a pass that inserts
/// prolog and epilog code, and eliminates abstract frame references.
///
-FunctionPass *createPrologEpilogCodeInserter() { return new PEI(); }
+FunctionPass *llvm::createPrologEpilogCodeInserter() { return new PEI(); }
/// saveCallerSavedRegisters - Scan the function for modified caller saved
///
void PEI::saveCallerSavedRegisters(MachineFunction &Fn) {
const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
- const TargetFrameInfo &FrameInfo = Fn.getTarget().getFrameInfo();
+ const TargetFrameInfo &FrameInfo = *Fn.getTarget().getFrameInfo();
// Get the callee saved register list...
const unsigned *CSRegs = RegInfo->getCalleeSaveRegs();
return;
// This bitset contains an entry for each physical register for the target...
- std::vector<bool> ModifiedRegs(MRegisterInfo::FirstVirtualRegister);
+ 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"
+ 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();
+ unsigned Size = I->getOperand(0).getImmedValue();
if (Size > MaxCallFrameSize) MaxCallFrameSize = Size;
HasCalls = true;
- RegInfo->eliminateCallFramePseudoInstr(Fn, *BB, I);
+ RegInfo->eliminateCallFramePseudoInstr(Fn, *BB, I++);
} else {
- for (unsigned i = 0, e = (*I)->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = (*I)->getOperand(i);
- assert(!MO.isVirtualRegister() &&
- "Register allocation must be performed!");
- if (MO.isRegister() && MO.isDef() &&
- MRegisterInfo::isPhysicalRegister(MO.getReg()))
+ 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;
}
}
// Add code to restore the callee-save registers in each exiting block.
- const TargetInstrInfo &TII = Fn.getTarget().getInstrInfo();
+ 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()-1;
+ 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]);
/// abstract stack objects...
///
void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
- const TargetFrameInfo &TFI = Fn.getTarget().getFrameInfo();
+ const TargetFrameInfo &TFI = *Fn.getTarget().getFrameInfo();
bool StackGrowsDown =
TFI.getStackGrowthDirection() == TargetFrameInfo::StackGrowsDown;
- assert(StackGrowsDown && "Only tested on stack down growing targets!");
// 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...
+ // 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) {
- Offset += FFI->getObjectSize(i); // Allocate Size bytes...
+ // 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...
- FFI->setObjectOffset(i, -Offset); // Set the computed offset
+ if (StackGrowsDown) {
+ FFI->setObjectOffset(i, -Offset); // Set the computed offset
+ } else {
+ FFI->setObjectOffset(i, Offset);
+ Offset += FFI->getObjectSize(i);
+ }
}
- // Align the final stack pointer offset...
- Offset = (Offset+StackAlignment-1)/StackAlignment*StackAlignment;
+ // Align the final stack pointer offset, but only if there are calls in the
+ // function. This ensures that any calls to subroutines have their stack
+ // frames suitable aligned.
+ if (FFI->hasCalls())
+ Offset = (Offset+StackAlignment-1)/StackAlignment*StackAlignment;
// Set the final value of the stack pointer...
- FFI->setStackSize(Offset-TFI.getOffsetOfLocalArea());
+ FFI->setStackSize(Offset+TFI.getOffsetOfLocalArea());
}
Fn.getTarget().getRegisterInfo()->emitPrologue(Fn);
// Add epilogue to restore the callee-save registers in each exiting block
- const TargetInstrInfo &TII = Fn.getTarget().getInstrInfo();
+ 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()))
+ if (!I->empty() && TII.isReturn(I->back().getOpcode()))
Fn.getTarget().getRegisterInfo()->emitEpilogue(Fn, *I);
}
}
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()) {
+ 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;
}
}
-
-} // End llvm namespace