[X86] Cache variables that only depend on the subtarget

There is a one-to-one relationship between X86Subtarget and
X86FrameLowering, but every frame lowering method would previously pull
the subtarget off the MachineFunction and query some subtarget
properties.

Over time, these locals began to grow in complexity and it became
important to keep their names and meaning in sync across all of the
frame lowering methods, leading to duplication. We can eliminate that
duplication by computing them once in the constructor.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239948 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86ExpandPseudo.cpp

@@ -89,14 +89,14 @@ bool X86ExpandPseudo::ExpandMI(MachineBasicBlock &MBB,
       const bool Uses64BitFramePtr =
           STI->isTarget64BitLP64() || STI->isTargetNaCl64();
       // Check if we should use LEA for SP.
+      const X86FrameLowering *TFI = STI->getFrameLowering();
       bool UseLEAForSP = STI->useLeaForSP() &&
                          X86FL->canUseLEAForSPInEpilogue(*MBB.getParent());
       unsigned StackPtr = TRI->getStackRegister();
       // Check for possible merge with preceding ADD instruction.
-      StackAdj += X86FrameLowering::mergeSPUpdates(MBB, MBBI, StackPtr, true);
+      StackAdj += TFI->mergeSPUpdates(MBB, MBBI, StackPtr, true);
-      X86FrameLowering::emitSPUpdate(MBB, MBBI, StackPtr, StackAdj, Is64Bit,
+      TFI->emitSPUpdate(MBB, MBBI, StackPtr, StackAdj, Is64Bit,
-                                     Uses64BitFramePtr, UseLEAForSP, *TII,
+                        Uses64BitFramePtr, UseLEAForSP, *TII, *TRI);
-                                     *TRI);
     }
 
     // Jump to label or value in register.

lib/Target/X86/X86FrameLowering.cpp

@@ -37,6 +37,19 @@ using namespace llvm;
 // FIXME: completely move here.
 extern cl::opt<bool> ForceStackAlign;
 
+X86FrameLowering::X86FrameLowering(const X86Subtarget &STI,
+                                   unsigned StackAlignOverride)
+    : TargetFrameLowering(StackGrowsDown, StackAlignOverride,
+                          STI.is64Bit() ? -8 : -4),
+      STI(STI), TII(*STI.getInstrInfo()), RegInfo(STI.getRegisterInfo()) {
+  // Cache a bunch of frame-related predicates for this subtarget.
+  SlotSize = RegInfo->getSlotSize();
+  Is64Bit = STI.is64Bit();
+  IsLP64 = STI.isTarget64BitLP64();
+  // standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
+  Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
+}
+
 bool X86FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
   return !MF.getFrameInfo()->hasVarSizedObjects() &&
          !MF.getInfo<X86MachineFunctionInfo>()->getHasPushSequences();
@@ -48,11 +61,9 @@ bool X86FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
 /// Use a more nuanced condition.
 bool
 X86FrameLowering::canSimplifyCallFramePseudos(const MachineFunction &MF) const {
-  const X86RegisterInfo *TRI = static_cast<const X86RegisterInfo *>
-                               (MF.getSubtarget().getRegisterInfo());
   return hasReservedCallFrame(MF) ||
-         (hasFP(MF) && !TRI->needsStackRealignment(MF))
+         (hasFP(MF) && !RegInfo->needsStackRealignment(MF)) ||
-         || TRI->hasBasePointer(MF);
+         RegInfo->hasBasePointer(MF);
 }
 
 // needsFrameIndexResolution - Do we need to perform FI resolution for
@@ -74,7 +85,6 @@ X86FrameLowering::needsFrameIndexResolution(const MachineFunction &MF) const {
 bool X86FrameLowering::hasFP(const MachineFunction &MF) const {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   const MachineModuleInfo &MMI = MF.getMMI();
-  const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo();
 
   return (MF.getTarget().Options.DisableFramePointerElim(MF) ||
           RegInfo->needsStackRealignment(MF) ||
@@ -210,7 +220,7 @@ void X86FrameLowering::emitSPUpdate(MachineBasicBlock &MBB,
                                     unsigned StackPtr, int64_t NumBytes,
                                     bool Is64BitTarget, bool Is64BitStackPtr,
                                     bool UseLEA, const TargetInstrInfo &TII,
-                                    const TargetRegisterInfo &TRI) {
+                                    const TargetRegisterInfo &TRI) const {
   bool isSub = NumBytes < 0;
   uint64_t Offset = isSub ? -NumBytes : NumBytes;
   unsigned Opc;
@@ -316,7 +326,7 @@ void mergeSPUpdatesUp(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
 int X86FrameLowering::mergeSPUpdates(MachineBasicBlock &MBB,
                                      MachineBasicBlock::iterator &MBBI,
                                      unsigned StackPtr,
-                                     bool doMergeWithPrevious) {
+                                     bool doMergeWithPrevious) const {
   if ((doMergeWithPrevious && MBBI == MBB.begin()) ||
       (!doMergeWithPrevious && MBBI == MBB.end()))
     return 0;
@@ -363,7 +373,6 @@ X86FrameLowering::emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
   MachineFrameInfo *MFI = MF.getFrameInfo();
   MachineModuleInfo &MMI = MF.getMMI();
   const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
-  const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
 
   // Add callee saved registers to move list.
   const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
@@ -401,10 +410,7 @@ static bool usesTheStack(const MachineFunction &MF) {
 void X86FrameLowering::emitStackProbeCall(MachineFunction &MF,
                                           MachineBasicBlock &MBB,
                                           MachineBasicBlock::iterator MBBI,
-                                          DebugLoc DL) {
+                                          DebugLoc DL) const {
-  const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
-  const TargetInstrInfo &TII = *STI.getInstrInfo();
-  bool Is64Bit = STI.is64Bit();
   bool IsLargeCodeModel = MF.getTarget().getCodeModel() == CodeModel::Large;
 
   unsigned CallOp;
@@ -470,13 +476,10 @@ static unsigned calculateSetFPREG(uint64_t SPAdjust) {
 // info, we need to know the ABI stack alignment as well in case we
 // have a call out.  Otherwise just make sure we have some alignment - we'll
 // go with the minimum SlotSize.
-static uint64_t calculateMaxStackAlign(const MachineFunction &MF) {
+uint64_t X86FrameLowering::calculateMaxStackAlign(const MachineFunction &MF) const {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   uint64_t MaxAlign = MFI->getMaxAlignment(); // Desired stack alignment.
-  const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
+  unsigned StackAlign = getStackAlignment();
-  const X86RegisterInfo *RegInfo = STI.getRegisterInfo();
-  unsigned SlotSize = RegInfo->getSlotSize();
-  unsigned StackAlign = STI.getFrameLowering()->getStackAlignment();
   if (ForceStackAlign) {
     if (MFI->hasCalls())
       MaxAlign = (StackAlign > MaxAlign) ? StackAlign : MaxAlign;
@@ -572,28 +575,22 @@ static uint64_t calculateMaxStackAlign(const MachineFunction &MF) {
 
 void X86FrameLowering::emitPrologue(MachineFunction &MF,
                                     MachineBasicBlock &MBB) const {
+  assert(&STI == &MF.getSubtarget<X86Subtarget>() &&
+         "MF used frame lowering for wrong subtarget");
   MachineBasicBlock::iterator MBBI = MBB.begin();
   MachineFrameInfo *MFI = MF.getFrameInfo();
   const Function *Fn = MF.getFunction();
-  const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
-  const X86RegisterInfo *RegInfo = STI.getRegisterInfo();
-  const TargetInstrInfo &TII = *STI.getInstrInfo();
   MachineModuleInfo &MMI = MF.getMMI();
   X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
   uint64_t MaxAlign = calculateMaxStackAlign(MF); // Desired stack alignment.
   uint64_t StackSize = MFI->getStackSize();    // Number of bytes to allocate.
   bool HasFP = hasFP(MF);
-  bool Is64Bit = STI.is64Bit();
-  // standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
-  const bool Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
   bool IsWin64CC = STI.isCallingConvWin64(Fn->getCallingConv());
-  // Not necessarily synonymous with IsWin64CC.
   bool IsWin64Prologue = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
   bool NeedsWinCFI = IsWin64Prologue && Fn->needsUnwindTableEntry();
   bool NeedsDwarfCFI =
       !IsWin64Prologue && (MMI.hasDebugInfo() || Fn->needsUnwindTableEntry());
   bool UseLEA = STI.useLeaForSP();
-  unsigned SlotSize = RegInfo->getSlotSize();
   unsigned FramePtr = RegInfo->getFrameRegister(MF);
   const unsigned MachineFramePtr =
       STI.isTarget64BitILP32()
@@ -997,18 +994,12 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
                                     MachineBasicBlock &MBB) const {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
-  const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
-  const X86RegisterInfo *RegInfo = STI.getRegisterInfo();
-  const TargetInstrInfo &TII = *STI.getInstrInfo();
   MachineBasicBlock::iterator MBBI = MBB.getFirstTerminator();
   DebugLoc DL;
   if (MBBI != MBB.end())
     DL = MBBI->getDebugLoc();
-  bool Is64Bit = STI.is64Bit();
   // standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
-  const bool Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
   const bool Is64BitILP32 = STI.isTarget64BitILP32();
-  unsigned SlotSize = RegInfo->getSlotSize();
   unsigned FramePtr = RegInfo->getFrameRegister(MF);
   unsigned MachineFramePtr =
       Is64BitILP32 ? getX86SubSuperRegister(FramePtr, MVT::i64, false)
@@ -1024,7 +1015,7 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
   // a ADD that will redefine the eflags and break the condition.
   // Alternatively, we could move the ADD, but this may not be possible
   // and is an optimization anyway.
-  if (UseLEAForSP && !MF.getSubtarget<X86Subtarget>().useLeaForSP())
+  if (UseLEAForSP && STI.useLeaForSP())
     UseLEAForSP = terminatorsNeedFlagsAsInput(MBB);
   // If that assert breaks, that means we do not do the right thing
   // in canUseAsEpilogue.
@@ -1135,8 +1126,6 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
 
 int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF,
                                           int FI) const {
-  const X86RegisterInfo *RegInfo =
-      MF.getSubtarget<X86Subtarget>().getRegisterInfo();
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   // Offset will hold the offset from the stack pointer at function entry to the
   // object.
@@ -1146,7 +1135,6 @@ int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF,
   const X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
   unsigned CSSize = X86FI->getCalleeSavedFrameSize();
   uint64_t StackSize = MFI->getStackSize();
-  unsigned SlotSize = RegInfo->getSlotSize();
   bool HasFP = hasFP(MF);
   bool IsWin64Prologue = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
   int64_t FPDelta = 0;
@@ -1211,8 +1199,6 @@ int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF,
 
 int X86FrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI,
                                              unsigned &FrameReg) const {
-  const X86RegisterInfo *RegInfo =
-      MF.getSubtarget<X86Subtarget>().getRegisterInfo();
   // We can't calculate offset from frame pointer if the stack is realigned,
   // so enforce usage of stack/base pointer.  The base pointer is used when we
   // have dynamic allocas in addition to dynamic realignment.
@@ -1232,8 +1218,6 @@ int X86FrameLowering::getFrameIndexOffsetFromSP(const MachineFunction &MF, int F
   const uint64_t StackSize = MFI->getStackSize();
   {
 #ifndef NDEBUG
-    const X86RegisterInfo *RegInfo =
-        MF.getSubtarget<X86Subtarget>().getRegisterInfo();
     // Note: LLVM arranges the stack as:
     // Args > Saved RetPC (<--FP) > CSRs > dynamic alignment (<--BP)
     //      > "Stack Slots" (<--SP)
@@ -1290,8 +1274,6 @@ int X86FrameLowering::getFrameIndexOffsetFromSP(const MachineFunction &MF, int F
 int X86FrameLowering::getFrameIndexReferenceFromSP(const MachineFunction &MF,
                                                    int FI,
                                                    unsigned &FrameReg) const {
-  const X86RegisterInfo *RegInfo =
-      MF.getSubtarget<X86Subtarget>().getRegisterInfo();
   assert(!RegInfo->hasBasePointer(MF) && "we don't handle this case");
 
   FrameReg = RegInfo->getStackRegister();
@@ -1302,9 +1284,6 @@ bool X86FrameLowering::assignCalleeSavedSpillSlots(
     MachineFunction &MF, const TargetRegisterInfo *TRI,
     std::vector<CalleeSavedInfo> &CSI) const {
   MachineFrameInfo *MFI = MF.getFrameInfo();
-  const X86RegisterInfo *RegInfo =
-      MF.getSubtarget<X86Subtarget>().getRegisterInfo();
-  unsigned SlotSize = RegInfo->getSlotSize();
   X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
 
   unsigned CalleeSavedFrameSize = 0;
@@ -1369,10 +1348,6 @@ bool X86FrameLowering::spillCalleeSavedRegisters(
     const TargetRegisterInfo *TRI) const {
   DebugLoc DL = MBB.findDebugLoc(MI);
 
-  MachineFunction &MF = *MBB.getParent();
-  const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
-  const TargetInstrInfo &TII = *STI.getInstrInfo();
-
   // Push GPRs. It increases frame size.
   unsigned Opc = STI.is64Bit() ? X86::PUSH64r : X86::PUSH32r;
   for (unsigned i = CSI.size(); i != 0; --i) {
@@ -1416,10 +1391,6 @@ bool X86FrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
 
   DebugLoc DL = MBB.findDebugLoc(MI);
 
-  MachineFunction &MF = *MBB.getParent();
-  const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
-  const TargetInstrInfo &TII = *STI.getInstrInfo();
-
   // Reload XMMs from stack frame.
   for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
     unsigned Reg = CSI[i].getReg();
@@ -1448,9 +1419,6 @@ void
 X86FrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
                                                        RegScavenger *RS) const {
   MachineFrameInfo *MFI = MF.getFrameInfo();
-  const X86RegisterInfo *RegInfo =
-      MF.getSubtarget<X86Subtarget>().getRegisterInfo();
-  unsigned SlotSize = RegInfo->getSlotSize();
 
   X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
   int64_t TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
@@ -1529,11 +1497,7 @@ static const uint64_t kSplitStackAvailable = 256;
 void X86FrameLowering::adjustForSegmentedStacks(
     MachineFunction &MF, MachineBasicBlock &PrologueMBB) const {
   MachineFrameInfo *MFI = MF.getFrameInfo();
-  const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
-  const TargetInstrInfo &TII = *STI.getInstrInfo();
   uint64_t StackSize;
-  bool Is64Bit = STI.is64Bit();
-  const bool IsLP64 = STI.isTarget64BitLP64();
   unsigned TlsReg, TlsOffset;
   DebugLoc DL;
 
@@ -1779,12 +1743,7 @@ void X86FrameLowering::adjustForSegmentedStacks(
 ///       if( temp0 < SP_LIMIT(P) ) goto IncStack else goto OldStart
 void X86FrameLowering::adjustForHiPEPrologue(
     MachineFunction &MF, MachineBasicBlock &PrologueMBB) const {
-  const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
-  const TargetInstrInfo &TII = *STI.getInstrInfo();
   MachineFrameInfo *MFI = MF.getFrameInfo();
-  const unsigned SlotSize = STI.getRegisterInfo()->getSlotSize();
-  const bool Is64Bit = STI.is64Bit();
-  const bool IsLP64 = STI.isTarget64BitLP64();
   DebugLoc DL;
   // HiPE-specific values
   const unsigned HipeLeafWords = 24;
@@ -1912,14 +1871,10 @@ void X86FrameLowering::adjustForHiPEPrologue(
 void X86FrameLowering::
 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I) const {
-  const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
+  unsigned StackPtr = RegInfo->getStackRegister();
-  const TargetInstrInfo &TII = *STI.getInstrInfo();
-  const X86RegisterInfo &RegInfo = *STI.getRegisterInfo();
-  unsigned StackPtr = RegInfo.getStackRegister();
   bool reserveCallFrame = hasReservedCallFrame(MF);
   unsigned Opcode = I->getOpcode();
   bool isDestroy = Opcode == TII.getCallFrameDestroyOpcode();
-  bool IsLP64 = STI.isTarget64BitLP64();
   DebugLoc DL = I->getDebugLoc();
   uint64_t Amount = !reserveCallFrame ? I->getOperand(0).getImm() : 0;
   uint64_t InternalAmt = (isDestroy || Amount) ? I->getOperand(1).getImm() : 0;

lib/Target/X86/X86FrameLowering.h

@@ -18,16 +18,36 @@
 
 namespace llvm {
 
+class X86Subtarget;
+class X86RegisterInfo;
+
 class X86FrameLowering : public TargetFrameLowering {
 public:
-  explicit X86FrameLowering(StackDirection D, unsigned StackAl, int LAO)
+  X86FrameLowering(const X86Subtarget &STI, unsigned StackAlignOverride);
-    : TargetFrameLowering(StackGrowsDown, StackAl, LAO) {}
+
+  // Cached subtarget predicates.
+
+  const X86Subtarget &STI;
+  const TargetInstrInfo &TII;
+  const X86RegisterInfo *RegInfo;
+
+  unsigned SlotSize;
+
+  /// Is64Bit implies that x86_64 instructions are available.
+  bool Is64Bit;
+
+  bool IsLP64;
+
+  /// True if the 64-bit frame or stack pointer should be used. True for most
+  /// 64-bit targets with the exception of x32. If this is false, 32-bit
+  /// instruction operands should be used to manipulate StackPtr and FramePtr.
+  bool Uses64BitFramePtr;
 
   /// Emit a call to the target's stack probe function. This is required for all
   /// large stack allocations on Windows. The caller is required to materialize
   /// the number of bytes to probe in RAX/EAX.
-  static void emitStackProbeCall(MachineFunction &MF, MachineBasicBlock &MBB,
+  void emitStackProbeCall(MachineFunction &MF, MachineBasicBlock &MBB,
-                                 MachineBasicBlock::iterator MBBI, DebugLoc DL);
+                          MachineBasicBlock::iterator MBBI, DebugLoc DL) const;
 
   void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
                                  MachineBasicBlock::iterator MBBI,
@@ -83,18 +103,16 @@ public:
   /// it is an ADD/SUB/LEA instruction it is deleted argument and the
   /// stack adjustment is returned as a positive value for ADD/LEA and
   /// a negative for SUB.
-  static int mergeSPUpdates(MachineBasicBlock &MBB,
+  int mergeSPUpdates(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
-                            MachineBasicBlock::iterator &MBBI,
+                     unsigned StackPtr, bool doMergeWithPrevious) const;
-                            unsigned StackPtr, bool doMergeWithPrevious);
 
   /// Emit a series of instructions to increment / decrement the stack
   /// pointer by a constant value.
-  static void emitSPUpdate(MachineBasicBlock &MBB,
+  void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
-                           MachineBasicBlock::iterator &MBBI, unsigned StackPtr,
+                    unsigned StackPtr, int64_t NumBytes, bool Is64BitTarget,
-                           int64_t NumBytes, bool Is64BitTarget,
                     bool Is64BitStackPtr, bool UseLEA,
                     const TargetInstrInfo &TII,
-                           const TargetRegisterInfo &TRI);
+                    const TargetRegisterInfo &TRI) const;
 
   /// Check that LEA can be used on SP in an epilogue sequence for \p MF.
   bool canUseLEAForSPInEpilogue(const MachineFunction &MF) const;
@@ -115,6 +133,8 @@ private:
                               MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I, 
                               uint64_t Amount) const;
+
+  uint64_t calculateMaxStackAlign(const MachineFunction &MF) const;
 };
 
 } // End llvm namespace

lib/Target/X86/X86ISelLowering.cpp

@@ -19683,7 +19683,8 @@ X86TargetLowering::EmitLoweredWinAlloca(MachineInstr *MI,
 
   assert(!Subtarget->isTargetMachO());
 
-  X86FrameLowering::emitStackProbeCall(*BB->getParent(), *BB, MI, DL);
+  Subtarget->getFrameLowering()->emitStackProbeCall(*BB->getParent(), *BB, MI,
+                                                    DL);
 
   MI->eraseFromParent();   // The pseudo instruction is gone now.
   return BB;

lib/Target/X86/X86Subtarget.cpp

@@ -300,8 +300,7 @@ X86Subtarget::X86Subtarget(const Triple &TT, const std::string &CPU,
                   TargetTriple.getEnvironment() == Triple::CODE16),
       TSInfo(*TM.getDataLayout()),
       InstrInfo(initializeSubtargetDependencies(CPU, FS)), TLInfo(TM, *this),
-      FrameLowering(TargetFrameLowering::StackGrowsDown, getStackAlignment(),
+      FrameLowering(*this, getStackAlignment()) {
-                    is64Bit() ? -8 : -4) {
   // Determine the PICStyle based on the target selected.
   if (TM.getRelocationModel() == Reloc::Static) {
     // Unless we're in PIC or DynamicNoPIC mode, set the PIC style to None.