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llvm-6502/lib/CodeGen/MachineFunction.cpp
Reid Kleckner 221a7075cf Add the llvm.frameallocate and llvm.recoverframeallocation intrinsics 
These intrinsics allow multiple functions to share a single stack
allocation from one function's call frame. The function with the
allocation may only perform one allocation, and it must be in the entry
block.

Functions accessing the allocation call llvm.recoverframeallocation with
the function whose frame they are accessing and a frame pointer from an
active call frame of that function.

These intrinsics are very difficult to inline correctly, so the
intention is that they be introduced rarely, or at least very late
during EH preparation.

Reviewers: echristo, andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D6493

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225746 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 00:48:10 +00:00

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//===-- MachineFunction.cpp -----------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Collect native machine code information for a function. This allows
// target-specific information about the generated code to be stored with each
// function.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/GraphWriter.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
#define DEBUG_TYPE "codegen"
//===----------------------------------------------------------------------===//
// MachineFunction implementation
//===----------------------------------------------------------------------===//
// Out of line virtual method.
MachineFunctionInfo::~MachineFunctionInfo() {}
void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
MBB->getParent()->DeleteMachineBasicBlock(MBB);
}
MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
unsigned FunctionNum, MachineModuleInfo &mmi)
: Fn(F), Target(TM), STI(TM.getSubtargetImpl()), Ctx(mmi.getContext()),
MMI(mmi) {
if (STI->getRegisterInfo())
RegInfo = new (Allocator) MachineRegisterInfo(this);
else
RegInfo = nullptr;
MFInfo = nullptr;
FrameInfo = new (Allocator)
MachineFrameInfo(STI->getFrameLowering()->getStackAlignment(),
STI->getFrameLowering()->isStackRealignable(),
!F->hasFnAttribute("no-realign-stack"));
if (Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
Attribute::StackAlignment))
FrameInfo->ensureMaxAlignment(Fn->getAttributes().
getStackAlignment(AttributeSet::FunctionIndex));
ConstantPool = new (Allocator) MachineConstantPool(TM);
Alignment = STI->getTargetLowering()->getMinFunctionAlignment();
// FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
if (!Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
Attribute::OptimizeForSize))
Alignment = std::max(Alignment,
STI->getTargetLowering()->getPrefFunctionAlignment());
FunctionNumber = FunctionNum;
JumpTableInfo = nullptr;
}
MachineFunction::~MachineFunction() {
// Don't call destructors on MachineInstr and MachineOperand. All of their
// memory comes from the BumpPtrAllocator which is about to be purged.
//
// Do call MachineBasicBlock destructors, it contains std::vectors.
for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))
I->Insts.clearAndLeakNodesUnsafely();
InstructionRecycler.clear(Allocator);
OperandRecycler.clear(Allocator);
BasicBlockRecycler.clear(Allocator);
if (RegInfo) {
RegInfo->~MachineRegisterInfo();
Allocator.Deallocate(RegInfo);
}
if (MFInfo) {
MFInfo->~MachineFunctionInfo();
Allocator.Deallocate(MFInfo);
}
FrameInfo->~MachineFrameInfo();
Allocator.Deallocate(FrameInfo);
ConstantPool->~MachineConstantPool();
Allocator.Deallocate(ConstantPool);
if (JumpTableInfo) {
JumpTableInfo->~MachineJumpTableInfo();
Allocator.Deallocate(JumpTableInfo);
}
}
/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
/// does already exist, allocate one.
MachineJumpTableInfo *MachineFunction::
getOrCreateJumpTableInfo(unsigned EntryKind) {
if (JumpTableInfo) return JumpTableInfo;
JumpTableInfo = new (Allocator)
MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
return JumpTableInfo;
}
/// Should we be emitting segmented stack stuff for the function
bool MachineFunction::shouldSplitStack() {
return getFunction()->hasFnAttribute("split-stack");
}
/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
/// recomputes them. This guarantees that the MBB numbers are sequential,
/// dense, and match the ordering of the blocks within the function. If a
/// specific MachineBasicBlock is specified, only that block and those after
/// it are renumbered.
void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
if (empty()) { MBBNumbering.clear(); return; }
MachineFunction::iterator MBBI, E = end();
if (MBB == nullptr)
MBBI = begin();
else
MBBI = MBB;
// Figure out the block number this should have.
unsigned BlockNo = 0;
if (MBBI != begin())
BlockNo = std::prev(MBBI)->getNumber() + 1;
for (; MBBI != E; ++MBBI, ++BlockNo) {
if (MBBI->getNumber() != (int)BlockNo) {
// Remove use of the old number.
if (MBBI->getNumber() != -1) {
assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
"MBB number mismatch!");
MBBNumbering[MBBI->getNumber()] = nullptr;
}
// If BlockNo is already taken, set that block's number to -1.
if (MBBNumbering[BlockNo])
MBBNumbering[BlockNo]->setNumber(-1);
MBBNumbering[BlockNo] = MBBI;
MBBI->setNumber(BlockNo);
}
}
// Okay, all the blocks are renumbered. If we have compactified the block
// numbering, shrink MBBNumbering now.
assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
MBBNumbering.resize(BlockNo);
}
/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
/// of `new MachineInstr'.
///
MachineInstr *
MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
DebugLoc DL, bool NoImp) {
return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
MachineInstr(*this, MCID, DL, NoImp);
}
/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
/// 'Orig' instruction, identical in all ways except the instruction
/// has no parent, prev, or next.
///
MachineInstr *
MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
MachineInstr(*this, *Orig);
}
/// DeleteMachineInstr - Delete the given MachineInstr.
///
/// This function also serves as the MachineInstr destructor - the real
/// ~MachineInstr() destructor must be empty.
void
MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
// Strip it for parts. The operand array and the MI object itself are
// independently recyclable.
if (MI->Operands)
deallocateOperandArray(MI->CapOperands, MI->Operands);
// Don't call ~MachineInstr() which must be trivial anyway because
// ~MachineFunction drops whole lists of MachineInstrs wihout calling their
// destructors.
InstructionRecycler.Deallocate(Allocator, MI);
}
/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
/// instead of `new MachineBasicBlock'.
///
MachineBasicBlock *
MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
MachineBasicBlock(*this, bb);
}
/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
///
void
MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
assert(MBB->getParent() == this && "MBB parent mismatch!");
MBB->~MachineBasicBlock();
BasicBlockRecycler.Deallocate(Allocator, MBB);
}
MachineMemOperand *
MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
uint64_t s, unsigned base_alignment,
const AAMDNodes &AAInfo,
const MDNode *Ranges) {
return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
AAInfo, Ranges);
}
MachineMemOperand *
MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
int64_t Offset, uint64_t Size) {
if (MMO->getValue())
return new (Allocator)
MachineMemOperand(MachinePointerInfo(MMO->getValue(),
MMO->getOffset()+Offset),
MMO->getFlags(), Size,
MMO->getBaseAlignment());
return new (Allocator)
MachineMemOperand(MachinePointerInfo(MMO->getPseudoValue(),
MMO->getOffset()+Offset),
MMO->getFlags(), Size,
MMO->getBaseAlignment());
}
MachineInstr::mmo_iterator
MachineFunction::allocateMemRefsArray(unsigned long Num) {
return Allocator.Allocate<MachineMemOperand *>(Num);
}
std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
MachineInstr::mmo_iterator End) {
// Count the number of load mem refs.
unsigned Num = 0;
for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
if ((*I)->isLoad())
++Num;
// Allocate a new array and populate it with the load information.
MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
unsigned Index = 0;
for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
if ((*I)->isLoad()) {
if (!(*I)->isStore())
// Reuse the MMO.
Result[Index] = *I;
else {
// Clone the MMO and unset the store flag.
MachineMemOperand *JustLoad =
getMachineMemOperand((*I)->getPointerInfo(),
(*I)->getFlags() & ~MachineMemOperand::MOStore,
(*I)->getSize(), (*I)->getBaseAlignment(),
(*I)->getAAInfo());
Result[Index] = JustLoad;
}
++Index;
}
}
return std::make_pair(Result, Result + Num);
}
std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
MachineInstr::mmo_iterator End) {
// Count the number of load mem refs.
unsigned Num = 0;
for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
if ((*I)->isStore())
++Num;
// Allocate a new array and populate it with the store information.
MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
unsigned Index = 0;
for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
if ((*I)->isStore()) {
if (!(*I)->isLoad())
// Reuse the MMO.
Result[Index] = *I;
else {
// Clone the MMO and unset the load flag.
MachineMemOperand *JustStore =
getMachineMemOperand((*I)->getPointerInfo(),
(*I)->getFlags() & ~MachineMemOperand::MOLoad,
(*I)->getSize(), (*I)->getBaseAlignment(),
(*I)->getAAInfo());
Result[Index] = JustStore;
}
++Index;
}
}
return std::make_pair(Result, Result + Num);
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MachineFunction::dump() const {
print(dbgs());
}
#endif
StringRef MachineFunction::getName() const {
assert(getFunction() && "No function!");
return getFunction()->getName();
}
void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
OS << "# Machine code for function " << getName() << ": ";
if (RegInfo) {
OS << (RegInfo->isSSA() ? "SSA" : "Post SSA");
if (!RegInfo->tracksLiveness())
OS << ", not tracking liveness";
}
OS << '\n';
// Print Frame Information
FrameInfo->print(*this, OS);
// Print JumpTable Information
if (JumpTableInfo)
JumpTableInfo->print(OS);
// Print Constant Pool
ConstantPool->print(OS);
const TargetRegisterInfo *TRI = getSubtarget().getRegisterInfo();
if (RegInfo && !RegInfo->livein_empty()) {
OS << "Function Live Ins: ";
for (MachineRegisterInfo::livein_iterator
I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
OS << PrintReg(I->first, TRI);
if (I->second)
OS << " in " << PrintReg(I->second, TRI);
if (std::next(I) != E)
OS << ", ";
}
OS << '\n';
}
for (const auto &BB : *this) {
OS << '\n';
BB.print(OS, Indexes);
}
OS << "\n# End machine code for function " << getName() << ".\n\n";
}
namespace llvm {
template<>
struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
static std::string getGraphName(const MachineFunction *F) {
return "CFG for '" + F->getName().str() + "' function";
}
std::string getNodeLabel(const MachineBasicBlock *Node,
const MachineFunction *Graph) {
std::string OutStr;
{
raw_string_ostream OSS(OutStr);
if (isSimple()) {
OSS << "BB#" << Node->getNumber();
if (const BasicBlock *BB = Node->getBasicBlock())
OSS << ": " << BB->getName();
} else
Node->print(OSS);
}
if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
// Process string output to make it nicer...
for (unsigned i = 0; i != OutStr.length(); ++i)
if (OutStr[i] == '\n') { // Left justify
OutStr[i] = '\\';
OutStr.insert(OutStr.begin()+i+1, 'l');
}
return OutStr;
}
};
}
void MachineFunction::viewCFG() const
{
#ifndef NDEBUG
ViewGraph(this, "mf" + getName());
#else
errs() << "MachineFunction::viewCFG is only available in debug builds on "
<< "systems with Graphviz or gv!\n";
#endif // NDEBUG
}
void MachineFunction::viewCFGOnly() const
{
#ifndef NDEBUG
ViewGraph(this, "mf" + getName(), true);
#else
errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
<< "systems with Graphviz or gv!\n";
#endif // NDEBUG
}
/// addLiveIn - Add the specified physical register as a live-in value and
/// create a corresponding virtual register for it.
unsigned MachineFunction::addLiveIn(unsigned PReg,
const TargetRegisterClass *RC) {
MachineRegisterInfo &MRI = getRegInfo();
unsigned VReg = MRI.getLiveInVirtReg(PReg);
if (VReg) {
const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg);
(void)VRegRC;
// A physical register can be added several times.
// Between two calls, the register class of the related virtual register
// may have been constrained to match some operation constraints.
// In that case, check that the current register class includes the
// physical register and is a sub class of the specified RC.
assert((VRegRC == RC || (VRegRC->contains(PReg) &&
RC->hasSubClassEq(VRegRC))) &&
"Register class mismatch!");
return VReg;
}
VReg = MRI.createVirtualRegister(RC);
MRI.addLiveIn(PReg, VReg);
return VReg;
}
/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
/// normal 'L' label is returned.
MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
bool isLinkerPrivate) const {
const DataLayout *DL = getSubtarget().getDataLayout();
assert(JumpTableInfo && "No jump tables");
assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
const char *Prefix = isLinkerPrivate ? DL->getLinkerPrivateGlobalPrefix() :
DL->getPrivateGlobalPrefix();
SmallString<60> Name;
raw_svector_ostream(Name)
<< Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
return Ctx.GetOrCreateSymbol(Name.str());
}
/// getPICBaseSymbol - Return a function-local symbol to represent the PIC
/// base.
MCSymbol *MachineFunction::getPICBaseSymbol() const {
const DataLayout *DL = getSubtarget().getDataLayout();
return Ctx.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
Twine(getFunctionNumber())+"$pb");
}
//===----------------------------------------------------------------------===//
// MachineFrameInfo implementation
//===----------------------------------------------------------------------===//
/// ensureMaxAlignment - Make sure the function is at least Align bytes
/// aligned.
void MachineFrameInfo::ensureMaxAlignment(unsigned Align) {
if (!StackRealignable || !RealignOption)
assert(Align <= StackAlignment &&
"For targets without stack realignment, Align is out of limit!");
if (MaxAlignment < Align) MaxAlignment = Align;
}
/// clampStackAlignment - Clamp the alignment if requested and emit a warning.
static inline unsigned clampStackAlignment(bool ShouldClamp, unsigned Align,
unsigned StackAlign) {
if (!ShouldClamp || Align <= StackAlign)
return Align;
DEBUG(dbgs() << "Warning: requested alignment " << Align
<< " exceeds the stack alignment " << StackAlign
<< " when stack realignment is off" << '\n');
return StackAlign;
}
/// CreateStackObject - Create a new statically sized stack object, returning
/// a nonnegative identifier to represent it.
///
int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment,
bool isSS, const AllocaInst *Alloca) {
assert(Size != 0 && "Cannot allocate zero size stack objects!");
Alignment = clampStackAlignment(!StackRealignable || !RealignOption,
Alignment, StackAlignment);
Objects.push_back(StackObject(Size, Alignment, 0, false, isSS, Alloca,
!isSS));
int Index = (int)Objects.size() - NumFixedObjects - 1;
assert(Index >= 0 && "Bad frame index!");
ensureMaxAlignment(Alignment);
return Index;
}
/// CreateSpillStackObject - Create a new statically sized stack object that
/// represents a spill slot, returning a nonnegative identifier to represent
/// it.
///
int MachineFrameInfo::CreateSpillStackObject(uint64_t Size,
unsigned Alignment) {
Alignment = clampStackAlignment(!StackRealignable || !RealignOption,
Alignment, StackAlignment);
CreateStackObject(Size, Alignment, true);
int Index = (int)Objects.size() - NumFixedObjects - 1;
ensureMaxAlignment(Alignment);
return Index;
}
/// CreateVariableSizedObject - Notify the MachineFrameInfo object that a
/// variable sized object has been created. This must be created whenever a
/// variable sized object is created, whether or not the index returned is
/// actually used.
///
int MachineFrameInfo::CreateVariableSizedObject(unsigned Alignment,
const AllocaInst *Alloca) {
HasVarSizedObjects = true;
Alignment = clampStackAlignment(!StackRealignable || !RealignOption,
Alignment, StackAlignment);
Objects.push_back(StackObject(0, Alignment, 0, false, false, Alloca, true));
ensureMaxAlignment(Alignment);
return (int)Objects.size()-NumFixedObjects-1;
}
/// CreateFixedObject - Create a new object at a fixed location on the stack.
/// All fixed objects should be created before other objects are created for
/// efficiency. By default, fixed objects are immutable. This returns an
/// index with a negative value.
///
int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
bool Immutable, bool isAliased) {
assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
// The alignment of the frame index can be determined from its offset from
// the incoming frame position. If the frame object is at offset 32 and
// the stack is guaranteed to be 16-byte aligned, then we know that the
// object is 16-byte aligned.
unsigned Align = MinAlign(SPOffset, StackAlignment);
Align = clampStackAlignment(!StackRealignable || !RealignOption, Align,
StackAlignment);
Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
/*isSS*/ false,
/*Alloca*/ nullptr, isAliased));
return -++NumFixedObjects;
}
/// CreateFixedSpillStackObject - Create a spill slot at a fixed location
/// on the stack. Returns an index with a negative value.
int MachineFrameInfo::CreateFixedSpillStackObject(uint64_t Size,
int64_t SPOffset) {
unsigned Align = MinAlign(SPOffset, StackAlignment);
Align = clampStackAlignment(!StackRealignable || !RealignOption, Align,
StackAlignment);
Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset,
/*Immutable*/ true,
/*isSS*/ true,
/*Alloca*/ nullptr,
/*isAliased*/ false));
return -++NumFixedObjects;
}
int MachineFrameInfo::CreateFrameAllocation(uint64_t Size) {
// Force the use of a frame pointer. The intention is that this intrinsic be
// used in conjunction with unwind mechanisms that leak the frame pointer.
setFrameAddressIsTaken(true);
Size = RoundUpToAlignment(Size, StackAlignment);
return CreateStackObject(Size, StackAlignment, false);
}
BitVector
MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
assert(MBB && "MBB must be valid");
const MachineFunction *MF = MBB->getParent();
assert(MF && "MBB must be part of a MachineFunction");
const TargetMachine &TM = MF->getTarget();
const TargetRegisterInfo *TRI = TM.getSubtargetImpl()->getRegisterInfo();
BitVector BV(TRI->getNumRegs());
// Before CSI is calculated, no registers are considered pristine. They can be
// freely used and PEI will make sure they are saved.
if (!isCalleeSavedInfoValid())
return BV;
for (const MCPhysReg *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
BV.set(*CSR);
// The entry MBB always has all CSRs pristine.
if (MBB == &MF->front())
return BV;
// On other MBBs the saved CSRs are not pristine.
const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
E = CSI.end(); I != E; ++I)
BV.reset(I->getReg());
return BV;
}
unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo();
unsigned MaxAlign = getMaxAlignment();
int Offset = 0;
// This code is very, very similar to PEI::calculateFrameObjectOffsets().
// It really should be refactored to share code. Until then, changes
// should keep in mind that there's tight coupling between the two.
for (int i = getObjectIndexBegin(); i != 0; ++i) {
int FixedOff = -getObjectOffset(i);
if (FixedOff > Offset) Offset = FixedOff;
}
for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
if (isDeadObjectIndex(i))
continue;
Offset += getObjectSize(i);
unsigned Align = getObjectAlignment(i);
// Adjust to alignment boundary
Offset = (Offset+Align-1)/Align*Align;
MaxAlign = std::max(Align, MaxAlign);
}
if (adjustsStack() && TFI->hasReservedCallFrame(MF))
Offset += 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 (adjustsStack() || hasVarSizedObjects() ||
(RegInfo->needsStackRealignment(MF) && 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);
return (unsigned)Offset;
}
void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
if (Objects.empty()) return;
const TargetFrameLowering *FI = MF.getSubtarget().getFrameLowering();
int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
OS << "Frame Objects:\n";
for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
const StackObject &SO = Objects[i];
OS << " fi#" << (int)(i-NumFixedObjects) << ": ";
if (SO.Size == ~0ULL) {
OS << "dead\n";
continue;
}
if (SO.Size == 0)
OS << "variable sized";
else
OS << "size=" << SO.Size;
OS << ", align=" << SO.Alignment;
if (i < NumFixedObjects)
OS << ", fixed";
if (i < NumFixedObjects || SO.SPOffset != -1) {
int64_t Off = SO.SPOffset - ValOffset;
OS << ", at location [SP";
if (Off > 0)
OS << "+" << Off;
else if (Off < 0)
OS << Off;
OS << "]";
}
OS << "\n";
}
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MachineFrameInfo::dump(const MachineFunction &MF) const {
print(MF, dbgs());
}
#endif
//===----------------------------------------------------------------------===//
// MachineJumpTableInfo implementation
//===----------------------------------------------------------------------===//
/// getEntrySize - Return the size of each entry in the jump table.
unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
// The size of a jump table entry is 4 bytes unless the entry is just the
// address of a block, in which case it is the pointer size.
switch (getEntryKind()) {
case MachineJumpTableInfo::EK_BlockAddress:
return TD.getPointerSize();
case MachineJumpTableInfo::EK_GPRel64BlockAddress:
return 8;
case MachineJumpTableInfo::EK_GPRel32BlockAddress:
case MachineJumpTableInfo::EK_LabelDifference32:
case MachineJumpTableInfo::EK_Custom32:
return 4;
case MachineJumpTableInfo::EK_Inline:
return 0;
}
llvm_unreachable("Unknown jump table encoding!");
}
/// getEntryAlignment - Return the alignment of each entry in the jump table.
unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
// The alignment of a jump table entry is the alignment of int32 unless the
// entry is just the address of a block, in which case it is the pointer
// alignment.
switch (getEntryKind()) {
case MachineJumpTableInfo::EK_BlockAddress:
return TD.getPointerABIAlignment();
case MachineJumpTableInfo::EK_GPRel64BlockAddress:
return TD.getABIIntegerTypeAlignment(64);
case MachineJumpTableInfo::EK_GPRel32BlockAddress:
case MachineJumpTableInfo::EK_LabelDifference32:
case MachineJumpTableInfo::EK_Custom32:
return TD.getABIIntegerTypeAlignment(32);
case MachineJumpTableInfo::EK_Inline:
return 1;
}
llvm_unreachable("Unknown jump table encoding!");
}
/// createJumpTableIndex - Create a new jump table entry in the jump table info.
///
unsigned MachineJumpTableInfo::createJumpTableIndex(
const std::vector<MachineBasicBlock*> &DestBBs) {
assert(!DestBBs.empty() && "Cannot create an empty jump table!");
JumpTables.push_back(MachineJumpTableEntry(DestBBs));
return JumpTables.size()-1;
}
/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
/// the jump tables to branch to New instead.
bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
MachineBasicBlock *New) {
assert(Old != New && "Not making a change?");
bool MadeChange = false;
for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
ReplaceMBBInJumpTable(i, Old, New);
return MadeChange;
}
/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
/// the jump table to branch to New instead.
bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
MachineBasicBlock *Old,
MachineBasicBlock *New) {
assert(Old != New && "Not making a change?");
bool MadeChange = false;
MachineJumpTableEntry &JTE = JumpTables[Idx];
for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
if (JTE.MBBs[j] == Old) {
JTE.MBBs[j] = New;
MadeChange = true;
}
return MadeChange;
}
void MachineJumpTableInfo::print(raw_ostream &OS) const {
if (JumpTables.empty()) return;
OS << "Jump Tables:\n";
for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
OS << " jt#" << i << ": ";
for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
}
OS << '\n';
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MachineJumpTableInfo::dump() const { print(dbgs()); }
#endif
//===----------------------------------------------------------------------===//
// MachineConstantPool implementation
//===----------------------------------------------------------------------===//
void MachineConstantPoolValue::anchor() { }
const DataLayout *MachineConstantPool::getDataLayout() const {
return TM.getSubtargetImpl()->getDataLayout();
}
Type *MachineConstantPoolEntry::getType() const {
if (isMachineConstantPoolEntry())
return Val.MachineCPVal->getType();
return Val.ConstVal->getType();
}
unsigned MachineConstantPoolEntry::getRelocationInfo() const {
if (isMachineConstantPoolEntry())
return Val.MachineCPVal->getRelocationInfo();
return Val.ConstVal->getRelocationInfo();
}
SectionKind
MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const {
SectionKind Kind;
switch (getRelocationInfo()) {
default:
llvm_unreachable("Unknown section kind");
case 2:
Kind = SectionKind::getReadOnlyWithRel();
break;
case 1:
Kind = SectionKind::getReadOnlyWithRelLocal();
break;
case 0:
switch (DL->getTypeAllocSize(getType())) {
case 4:
Kind = SectionKind::getMergeableConst4();
break;
case 8:
Kind = SectionKind::getMergeableConst8();
break;
case 16:
Kind = SectionKind::getMergeableConst16();
break;
default:
Kind = SectionKind::getMergeableConst();
break;
}
}
return Kind;
}
MachineConstantPool::~MachineConstantPool() {
for (unsigned i = 0, e = Constants.size(); i != e; ++i)
if (Constants[i].isMachineConstantPoolEntry())
delete Constants[i].Val.MachineCPVal;
for (DenseSet<MachineConstantPoolValue*>::iterator I =
MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
I != E; ++I)
delete *I;
}
/// CanShareConstantPoolEntry - Test whether the given two constants
/// can be allocated the same constant pool entry.
static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
const DataLayout *TD) {
// Handle the trivial case quickly.
if (A == B) return true;
// If they have the same type but weren't the same constant, quickly
// reject them.
if (A->getType() == B->getType()) return false;
// We can't handle structs or arrays.
if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
return false;
// For now, only support constants with the same size.
uint64_t StoreSize = TD->getTypeStoreSize(A->getType());
if (StoreSize != TD->getTypeStoreSize(B->getType()) || StoreSize > 128)
return false;
Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
// Try constant folding a bitcast of both instructions to an integer. If we
// get two identical ConstantInt's, then we are good to share them. We use
// the constant folding APIs to do this so that we get the benefit of
// DataLayout.
if (isa<PointerType>(A->getType()))
A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
const_cast<Constant*>(A), TD);
else if (A->getType() != IntTy)
A = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
const_cast<Constant*>(A), TD);
if (isa<PointerType>(B->getType()))
B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
const_cast<Constant*>(B), TD);
else if (B->getType() != IntTy)
B = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
const_cast<Constant*>(B), TD);
return A == B;
}
/// getConstantPoolIndex - Create a new entry in the constant pool or return
/// an existing one. User must specify the log2 of the minimum required
/// alignment for the object.
///
unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
unsigned Alignment) {
assert(Alignment && "Alignment must be specified!");
if (Alignment > PoolAlignment) PoolAlignment = Alignment;
// Check to see if we already have this constant.
//
// FIXME, this could be made much more efficient for large constant pools.
for (unsigned i = 0, e = Constants.size(); i != e; ++i)
if (!Constants[i].isMachineConstantPoolEntry() &&
CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C,
getDataLayout())) {
if ((unsigned)Constants[i].getAlignment() < Alignment)
Constants[i].Alignment = Alignment;
return i;
}
Constants.push_back(MachineConstantPoolEntry(C, Alignment));
return Constants.size()-1;
}
unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
unsigned Alignment) {
assert(Alignment && "Alignment must be specified!");
if (Alignment > PoolAlignment) PoolAlignment = Alignment;
// Check to see if we already have this constant.
//
// FIXME, this could be made much more efficient for large constant pools.
int Idx = V->getExistingMachineCPValue(this, Alignment);
if (Idx != -1) {
MachineCPVsSharingEntries.insert(V);
return (unsigned)Idx;
}
Constants.push_back(MachineConstantPoolEntry(V, Alignment));
return Constants.size()-1;
}
void MachineConstantPool::print(raw_ostream &OS) const {
if (Constants.empty()) return;
OS << "Constant Pool:\n";
for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
OS << " cp#" << i << ": ";
if (Constants[i].isMachineConstantPoolEntry())
Constants[i].Val.MachineCPVal->print(OS);
else
Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false);
OS << ", align=" << Constants[i].getAlignment();
OS << "\n";
}
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MachineConstantPool::dump() const { print(dbgs()); }
#endif
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