#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/MRegisterInfo.h"
#include "llvm/Target/TargetFrameInfo.h"
/// frame indexes with appropriate references.
///
bool runOnMachineFunction(MachineFunction &Fn) {
- // Get MachineDebugInfo so that we can track the construction of the
+ const MRegisterInfo *MRI = Fn.getTarget().getRegisterInfo();
+ RS = MRI->requiresRegisterScavenging(Fn) ? new RegScavenger() : NULL;
+
+ // Get MachineModuleInfo so that we can track the construction of the
// frame.
- if (MachineDebugInfo *DI = getAnalysisToUpdate<MachineDebugInfo>()) {
- Fn.getFrameInfo()->setMachineDebugInfo(DI);
+ if (MachineModuleInfo *MMI = getAnalysisToUpdate<MachineModuleInfo>()) {
+ Fn.getFrameInfo()->setMachineModuleInfo(MMI);
}
// Allow the target machine to make some adjustments to the function
// e.g. UsedPhysRegs before calculateCalleeSavedRegisters.
- Fn.getTarget().getRegisterInfo()
- ->processFunctionBeforeCalleeSavedScan(Fn);
+ MRI->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
//
replaceFrameIndices(Fn);
+ delete RS;
return true;
}
private:
+ RegScavenger *RS;
+
// MinCSFrameIndex, MaxCSFrameIndex - Keeps the range of callee saved
// stack frame indexes.
unsigned MinCSFrameIndex, MaxCSFrameIndex;
// 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 bool *PhysRegsUsed = Fn.getUsedPhysregs();
const TargetRegisterClass* const *CSRegClasses =
RegInfo->getCalleeSavedRegClasses();
std::vector<CalleeSavedInfo> CSI;
for (unsigned i = 0; CSRegs[i]; ++i) {
unsigned Reg = CSRegs[i];
- if (PhysRegsUsed[Reg]) {
+ if (Fn.isPhysRegUsed(Reg)) {
// If the reg is modified, save it!
CSI.push_back(CalleeSavedInfo(Reg, CSRegClasses[i]));
} else {
for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
*AliasSet; ++AliasSet) { // Check alias registers too.
- if (PhysRegsUsed[*AliasSet]) {
+ if (Fn.isPhysRegUsed(*AliasSet)) {
CSI.push_back(CalleeSavedInfo(Reg, CSRegClasses[i]));
break;
}
MachineBasicBlock::iterator I = MBB->begin();
if (!RegInfo->spillCalleeSavedRegisters(*MBB, I, CSI)) {
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ // Add the callee-saved register as live-in. It's killed at the spill.
+ MBB->addLiveIn(CSI[i].getReg());
+
// Insert the spill to the stack frame.
RegInfo->storeRegToStackSlot(*MBB, I, CSI[i].getReg(),
- CSI[i].getFrameIdx(),
- CSI[i].getRegClass());
+ CSI[i].getFrameIdx(), CSI[i].getRegClass());
}
}
// Loop over all of the stack objects, assigning sequential addresses...
MachineFrameInfo *FFI = Fn.getFrameInfo();
- unsigned StackAlignment = TFI.getStackAlignment();
unsigned MaxAlign = 0;
// 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();
+ int64_t Offset = TFI.getOffsetOfLocalArea();
if (StackGrowsDown)
Offset = -Offset;
assert(Offset >= 0
// 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;
+ 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
}
}
+ // Make sure the special register scavenging spill slot is closest to the
+ // frame pointer if a frame pointer is required.
+ const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
+ if (RS && RegInfo->hasFP(Fn)) {
+ int SFI = RS->getScavengingFrameIndex();
+ if (SFI >= 0) {
+ // If stack grows down, we need to add size of find the lowest
+ // address of the object.
+ if (StackGrowsDown)
+ Offset += FFI->getObjectSize(SFI);
+
+ unsigned Align = FFI->getObjectAlignment(SFI);
+ // Adjust to alignment boundary
+ Offset = (Offset+Align-1)/Align*Align;
+
+ if (StackGrowsDown) {
+ FFI->setObjectOffset(SFI, -Offset); // Set the computed offset
+ } else {
+ FFI->setObjectOffset(SFI, Offset);
+ Offset += FFI->getObjectSize(SFI);
+ }
+ }
+ }
+
// 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) {
if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
continue;
+ if (RS && (int)i == RS->getScavengingFrameIndex())
+ continue;
// If stack grows down, we need to add size of find the lowest
// address of the object.
}
}
- // Set the final value of the stack pointer...
+ // Make sure the special register scavenging spill slot is closest to the
+ // stack pointer.
+ if (RS) {
+ int SFI = RS->getScavengingFrameIndex();
+ if (SFI >= 0) {
+ // If stack grows down, we need to add size of find the lowest
+ // address of the object.
+ if (StackGrowsDown)
+ Offset += FFI->getObjectSize(SFI);
+
+ unsigned Align = FFI->getObjectAlignment(SFI);
+ // Adjust to alignment boundary
+ Offset = (Offset+Align-1)/Align*Align;
+
+ if (StackGrowsDown) {
+ FFI->setObjectOffset(SFI, -Offset); // Set the computed offset
+ } else {
+ FFI->setObjectOffset(SFI, Offset);
+ Offset += FFI->getObjectSize(SFI);
+ }
+ }
+ }
+
+ // 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.
+ if (!RegInfo->targetHandlesStackFrameRounding() &&
+ (FFI->hasCalls() || FFI->hasVarSizedObjects())) {
+ // When we have no frame pointer, we reserve argument space for call sites
+ // in the function immediately on entry to the current function. This
+ // eliminates the need for add/sub sp brackets around call sites.
+ if (!RegInfo->hasFP(Fn))
+ Offset += FFI->getMaxCallFrameSize();
+
+ unsigned AlignMask = TFI.getStackAlignment() - 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
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()) {
+ for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
+ if (RS) RS->enterBasicBlock(BB);
+ 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).isFrameIndex()) {
// If this instruction has a FrameIndex operand, we need to use that
// target machine register info object to eliminate it.
- MRI.eliminateFrameIndex(I);
+ MRI.eliminateFrameIndex(MI, RS);
+
+ // Revisit the instruction in full. Some instructions (e.g. inline
+ // asm instructions) can have multiple frame indices.
+ --I;
+ MI = 0;
break;
}
+ // Update register states.
+ if (RS && MI) RS->forward(MI);
+ }
+ }
}
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