/// AdjustStackOffset - Helper function used to adjust the stack frame offset. static inline void AdjustStackOffset(MachineFrameInfo &MFI, int FrameIdx, bool StackGrowsDown, int64_t &Offset, unsigned &MaxAlign, unsigned Skew) { // If the stack grows down, add the object size to find the lowest address. if (StackGrowsDown) Offset += MFI.getObjectSize(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. MaxAlign = std::max(MaxAlign, Align); // Adjust to alignment boundary. Offset = alignTo(Offset, Align, Skew); if (StackGrowsDown) { LLVM_DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") at SP[" << -Offset << "]\n"); MFI.setObjectOffset(FrameIdx, -Offset); // Set the computed offset } else { LLVM_DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") at SP[" << Offset << "]\n"); MFI.setObjectOffset(FrameIdx, Offset); Offset += MFI.getObjectSize(FrameIdx); } }
/// Assign frame object to an unused portion of the stack in the fixed stack /// object range. Return true if the allocation was successful. static inline bool scavengeStackSlot(MachineFrameInfo &MFI, int FrameIdx, bool StackGrowsDown, unsigned MaxAlign, BitVector &StackBytesFree) { if (MFI.isVariableSizedObjectIndex(FrameIdx)) return false; if (StackBytesFree.none()) { // clear it to speed up later scavengeStackSlot calls to // StackBytesFree.none() StackBytesFree.clear(); return false; } unsigned ObjAlign = MFI.getObjectAlignment(FrameIdx); if (ObjAlign > MaxAlign) return false; int64_t ObjSize = MFI.getObjectSize(FrameIdx); int FreeStart; for (FreeStart = StackBytesFree.find_first(); FreeStart != -1; FreeStart = StackBytesFree.find_next(FreeStart)) { // Check that free space has suitable alignment. unsigned ObjStart = StackGrowsDown ? FreeStart + ObjSize : FreeStart; if (alignTo(ObjStart, ObjAlign) != ObjStart) continue; if (FreeStart + ObjSize > StackBytesFree.size()) return false; bool AllBytesFree = true; for (unsigned Byte = 0; Byte < ObjSize; ++Byte) if (!StackBytesFree.test(FreeStart + Byte)) { AllBytesFree = false; break; } if (AllBytesFree) break; } if (FreeStart == -1) return false; if (StackGrowsDown) { int ObjStart = -(FreeStart + ObjSize); LLVM_DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") scavenged at SP[" << ObjStart << "]\n"); MFI.setObjectOffset(FrameIdx, ObjStart); } else { LLVM_DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") scavenged at SP[" << FreeStart << "]\n"); MFI.setObjectOffset(FrameIdx, FreeStart); } StackBytesFree.reset(FreeStart, FreeStart + ObjSize); return true; }
bool MIRParserImpl::initializeFrameInfo( const Function &F, MachineFrameInfo &MFI, const yaml::MachineFunction &YamlMF, DenseMap<unsigned, int> &StackObjectSlots, DenseMap<unsigned, int> &FixedStackObjectSlots) { const yaml::MachineFrameInfo &YamlMFI = YamlMF.FrameInfo; MFI.setFrameAddressIsTaken(YamlMFI.IsFrameAddressTaken); MFI.setReturnAddressIsTaken(YamlMFI.IsReturnAddressTaken); MFI.setHasStackMap(YamlMFI.HasStackMap); MFI.setHasPatchPoint(YamlMFI.HasPatchPoint); MFI.setStackSize(YamlMFI.StackSize); MFI.setOffsetAdjustment(YamlMFI.OffsetAdjustment); if (YamlMFI.MaxAlignment) MFI.ensureMaxAlignment(YamlMFI.MaxAlignment); MFI.setAdjustsStack(YamlMFI.AdjustsStack); MFI.setHasCalls(YamlMFI.HasCalls); MFI.setMaxCallFrameSize(YamlMFI.MaxCallFrameSize); MFI.setHasOpaqueSPAdjustment(YamlMFI.HasOpaqueSPAdjustment); MFI.setHasVAStart(YamlMFI.HasVAStart); MFI.setHasMustTailInVarArgFunc(YamlMFI.HasMustTailInVarArgFunc); // Initialize the fixed frame objects. for (const auto &Object : YamlMF.FixedStackObjects) { int ObjectIdx; if (Object.Type != yaml::FixedMachineStackObject::SpillSlot) ObjectIdx = MFI.CreateFixedObject(Object.Size, Object.Offset, Object.IsImmutable, Object.IsAliased); else ObjectIdx = MFI.CreateFixedSpillStackObject(Object.Size, Object.Offset); MFI.setObjectAlignment(ObjectIdx, Object.Alignment); // TODO: Report an error when objects are redefined. FixedStackObjectSlots.insert(std::make_pair(Object.ID, ObjectIdx)); } // Initialize the ordinary frame objects. for (const auto &Object : YamlMF.StackObjects) { int ObjectIdx; const AllocaInst *Alloca = nullptr; const yaml::StringValue &Name = Object.Name; if (!Name.Value.empty()) { Alloca = dyn_cast_or_null<AllocaInst>( F.getValueSymbolTable().lookup(Name.Value)); if (!Alloca) return error(Name.SourceRange.Start, "alloca instruction named '" + Name.Value + "' isn't defined in the function '" + F.getName() + "'"); } if (Object.Type == yaml::MachineStackObject::VariableSized) ObjectIdx = MFI.CreateVariableSizedObject(Object.Alignment, Alloca); else ObjectIdx = MFI.CreateStackObject( Object.Size, Object.Alignment, Object.Type == yaml::MachineStackObject::SpillSlot, Alloca); MFI.setObjectOffset(ObjectIdx, Object.Offset); // TODO: Report an error when objects are redefined. StackObjectSlots.insert(std::make_pair(Object.ID, ObjectIdx)); } return false; }
void MBlazeRegisterInfo:: processFunctionBeforeFrameFinalized(MachineFunction &MF) const { // Set the stack offset where GP must be saved/loaded from. MachineFrameInfo *MFI = MF.getFrameInfo(); MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>(); if (MBlazeFI->needGPSaveRestore()) MFI->setObjectOffset(MBlazeFI->getGPFI(), MBlazeFI->getGPStackOffset()); }
void Nios2RegisterInfo::adjustNios2StackFrame(MachineFunction &MF) const { MachineFrameInfo *MFI = MF.getFrameInfo(); Nios2FunctionInfo *Nios2FI = MF.getInfo<Nios2FunctionInfo>(); const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo(); unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment(); unsigned RegSize = 4; bool HasGP = Nios2FI->needGPSaveRestore(); // Min and Max CSI FrameIndex. int MinCSFI = -1, MaxCSFI = -1; // See the description at Nios2MachineFunction.h int TopCPUSavedRegOff = -1; // It happens that the default stack frame allocation order does not directly // map to the convention used for nios2. So we must fix it. We move the callee // save register slots after the local variables area, as described in the // stack frame above. unsigned CalleeSavedAreaSize = 0; if (!CSI.empty()) { MinCSFI = CSI[0].getFrameIdx(); MaxCSFI = CSI[CSI.size()-1].getFrameIdx(); } for (unsigned i = 0, e = CSI.size(); i != e; ++i) CalleeSavedAreaSize += MFI->getObjectAlignment(CSI[i].getFrameIdx()); unsigned StackOffset = HasGP ? (Nios2FI->getGPStackOffset()+RegSize) : 16; // Adjust local variables. They should come on the stack right // after the arguments. int LastOffsetFI = -1; for (int i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) { if (i >= MinCSFI && i <= MaxCSFI) continue; if (MFI->isDeadObjectIndex(i)) continue; unsigned Offset = StackOffset + MFI->getObjectOffset(i) - CalleeSavedAreaSize; if (LastOffsetFI == -1) LastOffsetFI = i; if (Offset > MFI->getObjectOffset(LastOffsetFI)) LastOffsetFI = i; MFI->setObjectOffset(i, Offset); } // Adjust CPU Callee Saved Registers Area. Registers RA and FP must // be saved in this CPU Area. This whole Area must be aligned to the // default Stack Alignment requirements. if (LastOffsetFI >= 0) StackOffset = MFI->getObjectOffset(LastOffsetFI)+ MFI->getObjectSize(LastOffsetFI); StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign); int stackSize = MF.getFrameInfo()->getStackSize(); if (MFI->hasCalls()) { stackSize += RegSize; } if (hasFP(MF)) { stackSize += RegSize; } for (unsigned i = 0, e = CSI.size(); i != e ; ++i) { if (CSI[i].getRegClass() != Nios2::CPURegsRegisterClass) break; stackSize += RegSize; } if (MFI->hasCalls()) { MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true), hasFP(MF) ? 4 : 0); Nios2FI->setRAStackOffset(hasFP(MF) ? 4 : 0); TopCPUSavedRegOff = hasFP(MF) ? 4 : 0; StackOffset += RegSize; } if (hasFP(MF)) { MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true), 0); Nios2FI->setFPStackOffset(0); TopCPUSavedRegOff = 0; StackOffset += RegSize; } for (unsigned i = 0, e = CSI.size(); i != e ; ++i) { if (CSI[i].getRegClass() != Nios2::CPURegsRegisterClass) break; MFI->setObjectOffset(CSI[i].getFrameIdx(), stackSize + (-(StackOffset + 4))); TopCPUSavedRegOff = stackSize + (-(StackOffset + 4)); StackOffset += MFI->getObjectAlignment(CSI[i].getFrameIdx()); } // Update frame info MFI->setStackSize(stackSize); }
/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the /// abstract stack objects. /// void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { const TargetFrameLowering &TFI = *Fn.getTarget().getFrameLowering(); bool StackGrowsDown = TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown; // Loop over all of the stack objects, assigning sequential addresses... 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. int LocalAreaOffset = TFI.getOffsetOfLocalArea(); if (StackGrowsDown) 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 = 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 = -MFI->getObjectOffset(i); } else { // The maximum distance from the start pointer is at the upper // address of the object. FixedOff = MFI->getObjectOffset(i) + MFI->getObjectSize(i); } if (FixedOff > Offset) Offset = FixedOff; } // First assign frame offsets to stack objects that are used to spill // callee saved registers. if (StackGrowsDown) { for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) { // If the stack grows down, we need to add the size to find the lowest // address of the object. Offset += MFI->getObjectSize(i); unsigned Align = MFI->getObjectAlignment(i); // Adjust to alignment boundary Offset = (Offset+Align-1)/Align*Align; MFI->setObjectOffset(i, -Offset); // Set the computed offset } } else { int MaxCSFI = MaxCSFrameIndex, MinCSFI = MinCSFrameIndex; for (int i = MaxCSFI; i >= MinCSFI ; --i) { unsigned Align = MFI->getObjectAlignment(i); // Adjust to alignment boundary Offset = (Offset+Align-1)/Align*Align; 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 && TFI.hasFP(Fn) && RegInfo->useFPForScavengingIndex(Fn) && !RegInfo->needsStackRealignment(Fn)) { int SFI = RS->getScavengingFrameIndex(); if (SFI >= 0) 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. 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 = 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 (LargeStackObjs.count(i)) continue; AdjustStackOffset(MFI, i, 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) || !RegInfo->useFPForScavengingIndex(Fn))) { int SFI = RS->getScavengingFrameIndex(); if (SFI >= 0) AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign); } 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 (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... int64_t StackSize = Offset - LocalAreaOffset; MFI->setStackSize(StackSize); NumBytesStackSpace += StackSize; }
/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the /// abstract stack objects. /// void PEI::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 *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. int LocalAreaOffset = TFI.getOffsetOfLocalArea(); if (StackGrowsDown) 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 = 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 = -MFI->getObjectOffset(i); } else { // The maximum distance from the start pointer is at the upper // address of the object. FixedOff = MFI->getObjectOffset(i) + MFI->getObjectSize(i); } if (FixedOff > Offset) Offset = FixedOff; } // First assign frame offsets to stack objects that are used to spill // callee saved registers. if (StackGrowsDown) { for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) { // If the stack grows down, we need to add the size to find the lowest // address of the object. Offset += MFI->getObjectSize(i); unsigned Align = MFI->getObjectAlignment(i); // Adjust to alignment boundary Offset = (Offset+Align-1)/Align*Align; MFI->setObjectOffset(i, -Offset); // Set the computed offset } } else { int MaxCSFI = MaxCSFrameIndex, MinCSFI = MinCSFrameIndex; for (int i = MaxCSFI; i >= MinCSFI ; --i) { unsigned Align = MFI->getObjectAlignment(i); // Adjust to alignment boundary Offset = (Offset+Align-1)/Align*Align; 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) && !RegInfo->needsStackRealignment(Fn)) { int SFI = RS->getScavengingFrameIndex(); if (SFI >= 0) AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign); } // Make sure that the stack protector comes before the local variables on the // stack. if (MFI->getStackProtectorIndex() >= 0) AdjustStackOffset(MFI, MFI->getStackProtectorIndex(), StackGrowsDown, Offset, MaxAlign); // Then assign frame offsets to stack objects that are not used to spill // callee saved registers. for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) { if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex) continue; if (RS && (int)i == RS->getScavengingFrameIndex()) continue; if (MFI->isDeadObjectIndex(i)) continue; if (MFI->getStackProtectorIndex() == (int)i) continue; 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) || RegInfo->needsStackRealignment(Fn))) { int SFI = RS->getScavengingFrameIndex(); if (SFI >= 0) AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign); } if (!RegInfo->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 (MFI->adjustsStack() && RegInfo->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... MFI->setStackSize(Offset - LocalAreaOffset); }
void MipsFrameInfo::adjustMipsStackFrame(MachineFunction &MF) const { MachineFrameInfo *MFI = MF.getFrameInfo(); MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>(); const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo(); unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment(); unsigned RegSize = STI.isGP32bit() ? 4 : 8; bool HasGP = MipsFI->needGPSaveRestore(); // Min and Max CSI FrameIndex. int MinCSFI = -1, MaxCSFI = -1; // See the description at MipsMachineFunction.h int TopCPUSavedRegOff = -1, TopFPUSavedRegOff = -1; // Replace the dummy '0' SPOffset by the negative offsets, as explained on // LowerFormalArguments. Leaving '0' for while is necessary to avoid the // approach done by calculateFrameObjectOffsets to the stack frame. MipsFI->adjustLoadArgsFI(MFI); MipsFI->adjustStoreVarArgsFI(MFI); // It happens that the default stack frame allocation order does not directly // map to the convention used for mips. So we must fix it. We move the callee // save register slots after the local variables area, as described in the // stack frame above. unsigned CalleeSavedAreaSize = 0; if (!CSI.empty()) { MinCSFI = CSI[0].getFrameIdx(); MaxCSFI = CSI[CSI.size()-1].getFrameIdx(); } for (unsigned i = 0, e = CSI.size(); i != e; ++i) CalleeSavedAreaSize += MFI->getObjectAlignment(CSI[i].getFrameIdx()); unsigned StackOffset = HasGP ? (MipsFI->getGPStackOffset()+RegSize) : (STI.isABI_O32() ? 16 : 0); // Adjust local variables. They should come on the stack right // after the arguments. int LastOffsetFI = -1; for (int i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) { if (i >= MinCSFI && i <= MaxCSFI) continue; if (MFI->isDeadObjectIndex(i)) continue; unsigned Offset = StackOffset + MFI->getObjectOffset(i) - CalleeSavedAreaSize; if (LastOffsetFI == -1) LastOffsetFI = i; if (Offset > MFI->getObjectOffset(LastOffsetFI)) LastOffsetFI = i; MFI->setObjectOffset(i, Offset); } // Adjust CPU Callee Saved Registers Area. Registers RA and FP must // be saved in this CPU Area. This whole area must be aligned to the // default Stack Alignment requirements. if (LastOffsetFI >= 0) StackOffset = MFI->getObjectOffset(LastOffsetFI)+ MFI->getObjectSize(LastOffsetFI); StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign); for (unsigned i = 0, e = CSI.size(); i != e ; ++i) { unsigned Reg = CSI[i].getReg(); if (!Mips::CPURegsRegisterClass->contains(Reg)) break; MFI->setObjectOffset(CSI[i].getFrameIdx(), StackOffset); TopCPUSavedRegOff = StackOffset; StackOffset += MFI->getObjectAlignment(CSI[i].getFrameIdx()); } // Stack locations for FP and RA. If only one of them is used, // the space must be allocated for both, otherwise no space at all. if (hasFP(MF) || MFI->adjustsStack()) { // FP stack location MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true), StackOffset); MipsFI->setFPStackOffset(StackOffset); TopCPUSavedRegOff = StackOffset; StackOffset += RegSize; // SP stack location MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true), StackOffset); MipsFI->setRAStackOffset(StackOffset); StackOffset += RegSize; if (MFI->adjustsStack()) TopCPUSavedRegOff += RegSize; } StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign); // Adjust FPU Callee Saved Registers Area. This Area must be // aligned to the default Stack Alignment requirements. for (unsigned i = 0, e = CSI.size(); i != e; ++i) { unsigned Reg = CSI[i].getReg(); if (Mips::CPURegsRegisterClass->contains(Reg)) continue; MFI->setObjectOffset(CSI[i].getFrameIdx(), StackOffset); TopFPUSavedRegOff = StackOffset; StackOffset += MFI->getObjectAlignment(CSI[i].getFrameIdx()); } StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign); // Update frame info MFI->setStackSize(StackOffset); // Recalculate the final tops offset. The final values must be '0' // if there isn't a callee saved register for CPU or FPU, otherwise // a negative offset is needed. if (TopCPUSavedRegOff >= 0) MipsFI->setCPUTopSavedRegOff(TopCPUSavedRegOff-StackOffset); if (TopFPUSavedRegOff >= 0) MipsFI->setFPUTopSavedRegOff(TopFPUSavedRegOff-StackOffset); }
SDValue Cpu0TargetLowering::LowerCall(SDValue InChain, SDValue Callee, CallingConv::ID CallConv, bool isVarArg, bool doesNotRet, bool &isTailCall, const SmallVectorImpl<ISD::OutputArg> &Outs, const SmallVectorImpl<SDValue> &OutVals, const SmallVectorImpl<ISD::InputArg> &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const { #if 1 // Cpu0 target does not yet support tail call optimization. isTailCall = false; MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); const TargetFrameLowering *TFL = MF.getTarget().getFrameLowering(); bool IsPIC = getTargetMachine().getRelocationModel() == Reloc::PIC_; Cpu0FunctionInfo *Cpu0FI = MF.getInfo<Cpu0FunctionInfo>(); // Analyze operands of the call, assigning locations to each operand. SmallVector<CCValAssign, 16> ArgLocs; CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), getTargetMachine(), ArgLocs, *DAG.getContext()); CCInfo.AnalyzeCallOperands(Outs, CC_Cpu0); // Get a count of how many bytes are to be pushed on the stack. unsigned NextStackOffset = CCInfo.getNextStackOffset(); // Chain is the output chain of the last Load/Store or CopyToReg node. // ByValChain is the output chain of the last Memcpy node created for copying // byval arguments to the stack. SDValue Chain, CallSeqStart, ByValChain; SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, true); Chain = CallSeqStart = DAG.getCALLSEQ_START(InChain, NextStackOffsetVal); ByValChain = InChain; #if 0 // If this is the first call, create a stack frame object that points to // a location to which .cprestore saves $gp. if (IsO32 && IsPIC && Cpu0FI->globalBaseRegFixed() && !Cpu0FI->getGPFI()) Cpu0FI->setGPFI(MFI->CreateFixedObject(4, 0, true)); #endif // Get the frame index of the stack frame object that points to the location // of dynamically allocated area on the stack. int DynAllocFI = Cpu0FI->getDynAllocFI(); #if 0 // Update size of the maximum argument space. // For O32, a minimum of four words (16 bytes) of argument space is // allocated. if (IsO32) NextStackOffset = std::max(NextStackOffset, (unsigned)16); #endif unsigned MaxCallFrameSize = Cpu0FI->getMaxCallFrameSize(); if (MaxCallFrameSize < NextStackOffset) { Cpu0FI->setMaxCallFrameSize(NextStackOffset); // Set the offsets relative to $sp of the $gp restore slot and dynamically // allocated stack space. These offsets must be aligned to a boundary // determined by the stack alignment of the ABI. unsigned StackAlignment = TFL->getStackAlignment(); NextStackOffset = (NextStackOffset + StackAlignment - 1) / StackAlignment * StackAlignment; if (Cpu0FI->needGPSaveRestore()) MFI->setObjectOffset(Cpu0FI->getGPFI(), NextStackOffset); MFI->setObjectOffset(DynAllocFI, NextStackOffset); } // With EABI is it possible to have 16 args on registers. SmallVector<std::pair<unsigned, SDValue>, 16> RegsToPass; SmallVector<SDValue, 8> MemOpChains; int FirstFI = -MFI->getNumFixedObjects() - 1, LastFI = 0; // Walk the register/memloc assignments, inserting copies/loads. for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { SDValue Arg = OutVals[i]; CCValAssign &VA = ArgLocs[i]; MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT(); ISD::ArgFlagsTy Flags = Outs[i].Flags; // ByVal Arg. if (Flags.isByVal()) { assert(Flags.getByValSize() && "ByVal args of size 0 should have been ignored by front-end."); #if 0 if (IsO32) WriteByValArg(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI, MFI, DAG, Arg, VA, Flags, getPointerTy(), Subtarget->isLittle()); #endif #if 0 else PassByValArg64(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI, MFI, DAG, Arg, VA, Flags, getPointerTy(), Subtarget->isLittle()); #endif continue; } // Promote the value if needed. switch (VA.getLocInfo()) { default: llvm_unreachable("Unknown loc info!"); case CCValAssign::Full: #if 0 if (VA.isRegLoc()) { if ((ValVT == MVT::f32 && LocVT == MVT::i32) || (ValVT == MVT::f64 && LocVT == MVT::i64)) Arg = DAG.getNode(ISD::BITCAST, dl, LocVT, Arg); else if (ValVT == MVT::f64 && LocVT == MVT::i32) { SDValue Lo = DAG.getNode(Cpu0ISD::ExtractElementF64, dl, MVT::i32, Arg, DAG.getConstant(0, MVT::i32)); SDValue Hi = DAG.getNode(Cpu0ISD::ExtractElementF64, dl, MVT::i32, Arg, DAG.getConstant(1, MVT::i32)); if (!Subtarget->isLittle()) std::swap(Lo, Hi); unsigned LocRegLo = VA.getLocReg(); unsigned LocRegHigh = getNextIntArgReg(LocRegLo); RegsToPass.push_back(std::make_pair(LocRegLo, Lo)); RegsToPass.push_back(std::make_pair(LocRegHigh, Hi)); continue; } } #else assert("CCValAssign::Full:"); // Gamma debug #endif break; case CCValAssign::SExt: Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, LocVT, Arg); break; case CCValAssign::ZExt: Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, LocVT, Arg); break; case CCValAssign::AExt: Arg = DAG.getNode(ISD::ANY_EXTEND, dl, LocVT, Arg); break; } // Arguments that can be passed on register must be kept at // RegsToPass vector if (VA.isRegLoc()) { RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg)); continue; } // Register can't get to this point... assert(VA.isMemLoc()); // Create the frame index object for this incoming parameter LastFI = MFI->CreateFixedObject(ValVT.getSizeInBits()/8, VA.getLocMemOffset(), true); SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy()); // emit ISD::STORE whichs stores the // parameter value to a stack Location MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff, MachinePointerInfo(), false, false, 0)); } // Extend range of indices of frame objects for outgoing arguments that were // created during this function call. Skip this step if no such objects were // created. if (LastFI) Cpu0FI->extendOutArgFIRange(FirstFI, LastFI); // If a memcpy has been created to copy a byval arg to a stack, replace the // chain input of CallSeqStart with ByValChain. if (InChain != ByValChain) DAG.UpdateNodeOperands(CallSeqStart.getNode(), ByValChain, NextStackOffsetVal); // Transform all store nodes into one single node because all store // nodes are independent of each other. if (!MemOpChains.empty()) Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &MemOpChains[0], MemOpChains.size()); // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol // node so that legalize doesn't hack it. unsigned char OpFlag; #if 0 // cpu0 int 32 only bool IsPICCall = (IsN64 || IsPIC); // true if calls are translated to jalr $25 #else bool IsPICCall = IsPIC; // true if calls are translated to jalr $25 #endif bool GlobalOrExternal = false; SDValue CalleeLo; if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) { if (IsPICCall && G->getGlobal()->hasInternalLinkage()) { OpFlag = Cpu0II::MO_GOT; #if 0 unsigned char LoFlag = IsO32 ? Cpu0II::MO_ABS_LO : Cpu0II::MO_GOT_OFST; #else unsigned char LoFlag = Cpu0II::MO_ABS_LO; #endif Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(), 0, OpFlag); CalleeLo = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(), 0, LoFlag); } else { OpFlag = IsPICCall ? Cpu0II::MO_GOT_CALL : Cpu0II::MO_NO_FLAG; Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(), 0, OpFlag); } GlobalOrExternal = true; } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) { if (!IsPIC) // static OpFlag = Cpu0II::MO_NO_FLAG; else // O32 & PIC OpFlag = Cpu0II::MO_GOT_CALL; Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy(), OpFlag); GlobalOrExternal = true; } SDValue InFlag; // Create nodes that load address of callee and copy it to T9 if (IsPICCall) { if (GlobalOrExternal) { // Load callee address Callee = DAG.getNode(Cpu0ISD::Wrapper, dl, getPointerTy(), GetGlobalReg(DAG, getPointerTy()), Callee); SDValue LoadValue = DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(), Callee, MachinePointerInfo::getGOT(), false, false, false, 0); // Use GOT+LO if callee has internal linkage. if (CalleeLo.getNode()) { SDValue Lo = DAG.getNode(Cpu0ISD::Lo, dl, getPointerTy(), CalleeLo); Callee = DAG.getNode(ISD::ADD, dl, getPointerTy(), LoadValue, Lo); } else Callee = LoadValue; } } // T9 should contain the address of the callee function if // -reloction-model=pic or it is an indirect call. if (IsPICCall || !GlobalOrExternal) { // copy to T9 unsigned T9Reg = Cpu0::T9; Chain = DAG.getCopyToReg(Chain, dl, T9Reg, Callee, SDValue(0, 0)); InFlag = Chain.getValue(1); Callee = DAG.getRegister(T9Reg, getPointerTy()); } // Build a sequence of copy-to-reg nodes chained together with token // chain and flag operands which copy the outgoing args into registers. // The InFlag in necessary since all emitted instructions must be // stuck together. for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) { Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first, RegsToPass[i].second, InFlag); InFlag = Chain.getValue(1); } // Cpu0JmpLink = #chain, #target_address, #opt_in_flags... // = Chain, Callee, Reg#1, Reg#2, ... // // Returns a chain & a flag for retval copy to use. SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); SmallVector<SDValue, 8> Ops; Ops.push_back(Chain); Ops.push_back(Callee); // Add argument registers to the end of the list so that they are // known live into the call. for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) Ops.push_back(DAG.getRegister(RegsToPass[i].first, RegsToPass[i].second.getValueType())); // Add a register mask operand representing the call-preserved registers. const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo(); const uint32_t *Mask = TRI->getCallPreservedMask(CallConv); assert(Mask && "Missing call preserved mask for calling convention"); Ops.push_back(DAG.getRegisterMask(Mask)); if (InFlag.getNode()) Ops.push_back(InFlag); Chain = DAG.getNode(Cpu0ISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size()); InFlag = Chain.getValue(1); // Create the CALLSEQ_END node. Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NextStackOffset, true), DAG.getIntPtrConstant(0, true), InFlag); InFlag = Chain.getValue(1); // Handle result values, copying them out of physregs into vregs that we // return. return LowerCallResult(Chain, InFlag, CallConv, isVarArg, Ins, dl, DAG, InVals); #else return InChain; #endif }
/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the /// abstract stack objects. /// void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { const TargetFrameLowering &TFI = *Fn.getSubtarget().getFrameLowering(); StackProtector *SP = &getAnalysis<StackProtector>(); bool StackGrowsDown = TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown; // Loop over all of the stack objects, assigning sequential addresses... 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. int LocalAreaOffset = TFI.getOffsetOfLocalArea(); if (StackGrowsDown) LocalAreaOffset = -LocalAreaOffset; assert(LocalAreaOffset >= 0 && "Local area offset should be in direction of stack growth"); int64_t Offset = LocalAreaOffset; // Skew to be applied to alignment. unsigned Skew = TFI.getStackAlignmentSkew(Fn); // 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 = 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 = -MFI->getObjectOffset(i); } else { // The maximum distance from the start pointer is at the upper // address of the object. FixedOff = MFI->getObjectOffset(i) + MFI->getObjectSize(i); } if (FixedOff > Offset) Offset = FixedOff; } // First assign frame offsets to stack objects that are used to spill // callee saved registers. if (StackGrowsDown) { for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) { // If the stack grows down, we need to add the size to find the lowest // address of the object. Offset += MFI->getObjectSize(i); unsigned Align = MFI->getObjectAlignment(i); // Adjust to alignment boundary Offset = alignTo(Offset, Align, Skew); DEBUG(dbgs() << "alloc FI(" << i << ") at SP[" << -Offset << "]\n"); MFI->setObjectOffset(i, -Offset); // Set the computed offset } } else { int MaxCSFI = MaxCSFrameIndex, MinCSFI = MinCSFrameIndex; for (int i = MaxCSFI; i >= MinCSFI ; --i) { unsigned Align = MFI->getObjectAlignment(i); // Adjust to alignment boundary Offset = alignTo(Offset, Align, Skew); DEBUG(dbgs() << "alloc FI(" << i << ") at SP[" << Offset << "]\n"); MFI->setObjectOffset(i, Offset); Offset += MFI->getObjectSize(i); } } unsigned MaxAlign = MFI->getMaxAlignment(); // Make sure the special register scavenging spill slot is closest to the // incoming stack pointer if a frame pointer is required and is closer // to the incoming rather than the final stack pointer. const TargetRegisterInfo *RegInfo = Fn.getSubtarget().getRegisterInfo(); bool EarlyScavengingSlots = (TFI.hasFP(Fn) && TFI.isFPCloseToIncomingSP() && RegInfo->useFPForScavengingIndex(Fn) && !RegInfo->needsStackRealignment(Fn)); if (RS && EarlyScavengingSlots) { SmallVector<int, 2> SFIs; RS->getScavengingFrameIndices(SFIs); for (SmallVectorImpl<int>::iterator I = SFIs.begin(), IE = SFIs.end(); I != IE; ++I) AdjustStackOffset(MFI, *I, StackGrowsDown, Offset, MaxAlign, Skew); } // 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 = alignTo(Offset, Align, Skew); 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. SmallSet<int, 16> ProtectedObjs; if (MFI->getStackProtectorIndex() >= 0) { StackObjSet LargeArrayObjs; StackObjSet SmallArrayObjs; StackObjSet AddrOfObjs; AdjustStackOffset(MFI, MFI->getStackProtectorIndex(), StackGrowsDown, Offset, MaxAlign, Skew); // 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 && RS->isScavengingFrameIndex((int)i)) continue; if (MFI->isDeadObjectIndex(i)) continue; if (MFI->getStackProtectorIndex() == (int)i) continue; switch (SP->getSSPLayout(MFI->getObjectAllocation(i))) { case StackProtector::SSPLK_None: continue; case StackProtector::SSPLK_SmallArray: SmallArrayObjs.insert(i); continue; case StackProtector::SSPLK_AddrOf: AddrOfObjs.insert(i); continue; case StackProtector::SSPLK_LargeArray: LargeArrayObjs.insert(i); continue; } llvm_unreachable("Unexpected SSPLayoutKind."); } AssignProtectedObjSet(LargeArrayObjs, ProtectedObjs, MFI, StackGrowsDown, Offset, MaxAlign, Skew); AssignProtectedObjSet(SmallArrayObjs, ProtectedObjs, MFI, StackGrowsDown, Offset, MaxAlign, Skew); AssignProtectedObjSet(AddrOfObjs, ProtectedObjs, MFI, StackGrowsDown, Offset, MaxAlign, Skew); } SmallVector<int, 8> ObjectsToAllocate; int EHRegNodeFrameIndex = INT_MAX; if (const WinEHFuncInfo *FuncInfo = Fn.getWinEHFuncInfo()) EHRegNodeFrameIndex = FuncInfo->EHRegNodeFrameIndex; // Then prepare to assign frame offsets to stack objects that are not used to // spill callee saved registers. 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 && RS->isScavengingFrameIndex((int)i)) continue; if (MFI->isDeadObjectIndex(i)) continue; if (MFI->getStackProtectorIndex() == (int)i) continue; if (EHRegNodeFrameIndex == (int)i) continue; if (ProtectedObjs.count(i)) continue; // Add the objects that we need to allocate to our working set. ObjectsToAllocate.push_back(i); } // Allocate the EH registration node first if one is present. if (EHRegNodeFrameIndex != INT_MAX) AdjustStackOffset(MFI, EHRegNodeFrameIndex, StackGrowsDown, Offset, MaxAlign, Skew); // Give the targets a chance to order the objects the way they like it. if (Fn.getTarget().getOptLevel() != CodeGenOpt::None && Fn.getTarget().Options.StackSymbolOrdering) TFI.orderFrameObjects(Fn, ObjectsToAllocate); // Now walk the objects and actually assign base offsets to them. for (auto &Object : ObjectsToAllocate) AdjustStackOffset(MFI, Object, StackGrowsDown, Offset, MaxAlign, Skew); // Make sure the special register scavenging spill slot is closest to the // stack pointer. if (RS && !EarlyScavengingSlots) { SmallVector<int, 2> SFIs; RS->getScavengingFrameIndices(SFIs); for (SmallVectorImpl<int>::iterator I = SFIs.begin(), IE = SFIs.end(); I != IE; ++I) AdjustStackOffset(MFI, *I, StackGrowsDown, Offset, MaxAlign, Skew); } 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 (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); Offset = alignTo(Offset, StackAlign, Skew); } // Update frame info to pretend that this is part of the stack... int64_t StackSize = Offset - LocalAreaOffset; MFI->setStackSize(StackSize); NumBytesStackSpace += StackSize; }