1 files changed, 211 insertions, 0 deletions
diff --git a/lib/Target/AArch64/AArch64RegisterInfo.cpp b/lib/Target/AArch64/AArch64RegisterInfo.cpp
new file mode 100644
index 0000000000..ce665048c3
--- /dev/null
+++ b/lib/Target/AArch64/AArch64RegisterInfo.cpp
@@ -0,0 +1,211 @@
+//===- AArch64RegisterInfo.cpp - AArch64 Register Information -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the AArch64 implementation of the TargetRegisterInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+
+#include "AArch64RegisterInfo.h"
+#include "AArch64FrameLowering.h"
+#include "AArch64MachineFunctionInfo.h"
+#include "AArch64TargetMachine.h"
+#include "MCTargetDesc/AArch64MCTargetDesc.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/ADT/BitVector.h"
+
+#define GET_REGINFO_TARGET_DESC
+#include "AArch64GenRegisterInfo.inc"
+
+using namespace llvm;
+
+AArch64RegisterInfo::AArch64RegisterInfo(const AArch64InstrInfo &tii,
+                                         const AArch64Subtarget &sti)
+  : AArch64GenRegisterInfo(AArch64::X30), TII(tii) {
+}
+
+const uint16_t *
+AArch64RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
+  return CSR_PCS_SaveList;
+}
+
+const uint32_t*
+AArch64RegisterInfo::getCallPreservedMask(CallingConv::ID) const {
+  return CSR_PCS_RegMask;
+}
+
+const uint32_t *AArch64RegisterInfo::getTLSDescCallPreservedMask() const {
+  return TLSDesc_RegMask;
+}
+
+const TargetRegisterClass *
+AArch64RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
+  if (RC == &AArch64::FlagClassRegClass)
+    return &AArch64::GPR64RegClass;
+
+  return RC;
+}
+
+
+
+BitVector
+AArch64RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
+  BitVector Reserved(getNumRegs());
+  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+
+  Reserved.set(AArch64::XSP);
+  Reserved.set(AArch64::WSP);
+
+  Reserved.set(AArch64::XZR);
+  Reserved.set(AArch64::WZR);
+
+  if (TFI->hasFP(MF)) {
+    Reserved.set(AArch64::X29);
+    Reserved.set(AArch64::W29);
+  }
+
+  return Reserved;
+}
+
+void
+AArch64RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MBBI,
+                                         int SPAdj, RegScavenger *RS) const {
+  assert(SPAdj == 0 && "Cannot deal with nonzero SPAdj yet");
+  MachineInstr &MI = *MBBI;
+  MachineBasicBlock &MBB = *MI.getParent();
+  MachineFunction &MF = *MBB.getParent();
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  const AArch64FrameLowering *TFI =
+    static_cast<const AArch64FrameLowering *>(MF.getTarget().getFrameLowering());
+
+  unsigned i = 0;
+  while (!MI.getOperand(i).isFI()) {
+    ++i;
+    assert(i < MI.getNumOperands() && "Instr doesn't have a FrameIndex Operand");
+  }
+
+  // In order to work out the base and offset for addressing, the FrameLowering
+  // code needs to know (sometimes) whether the instruction is storing/loading a
+  // callee-saved register, or whether it's a more generic
+  // operation. Fortunately the frame indices are used *only* for that purpose
+  // and are contiguous, so we can check here.
+  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+  int MinCSFI = 0;
+  int MaxCSFI = -1;
+
+  if (CSI.size()) {
+    MinCSFI = CSI[0].getFrameIdx();
+    MaxCSFI = CSI[CSI.size() - 1].getFrameIdx();
+  }
+
+  int FrameIndex = MI.getOperand(i).getIndex();
+  bool IsCalleeSaveOp = FrameIndex >= MinCSFI && FrameIndex <= MaxCSFI;
+
+  unsigned FrameReg;
+  int64_t Offset;
+  Offset = TFI->resolveFrameIndexReference(MF, FrameIndex, FrameReg, SPAdj,
+                                           IsCalleeSaveOp);
+
+  Offset += MI.getOperand(i+1).getImm();
+
+  // DBG_VALUE instructions have no real restrictions so they can be handled
+  // easily.
+  if (MI.isDebugValue()) {
+    MI.getOperand(i).ChangeToRegister(FrameReg, /*isDef=*/ false);
+    MI.getOperand(i+1).ChangeToImmediate(Offset);
+    return;
+  }
+
+  int MinOffset, MaxOffset, OffsetScale;
+  if (MI.getOpcode() == AArch64::ADDxxi_lsl0_s) {
+    MinOffset = 0;
+    MaxOffset = 0xfff;
+    OffsetScale = 1;
+  } else {
+    // Load/store of a stack object
+    TII.getAddressConstraints(MI, OffsetScale, MinOffset, MaxOffset);
+  }
+
+  // The frame lowering has told us a base and offset it thinks we should use to
+  // access this variable, but it's still up to us to make sure the values are
+  // legal for the instruction in question.
+  if (Offset % OffsetScale != 0 || Offset < MinOffset || Offset > MaxOffset) {
+    unsigned BaseReg =
+      MF.getRegInfo().createVirtualRegister(&AArch64::GPR64RegClass);
+    emitRegUpdate(MBB, MBBI, MBBI->getDebugLoc(), TII,
+                  BaseReg, FrameReg, BaseReg, Offset);
+    FrameReg = BaseReg;
+    Offset = 0;
+  }
+
+  // Negative offsets are expected if we address from FP, but for
+  // now this checks nothing has gone horribly wrong.
+  assert(Offset >= 0 && "Unexpected negative offset from SP");
+
+  MI.getOperand(i).ChangeToRegister(FrameReg, false, false, true);
+  MI.getOperand(i+1).ChangeToImmediate(Offset / OffsetScale);
+}
+
+void
+AArch64RegisterInfo::eliminateCallFramePseudoInstr(MachineFunction &MF,
+                                         MachineBasicBlock &MBB,
+                                         MachineBasicBlock::iterator MI) const {
+  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+  DebugLoc dl = MI->getDebugLoc();
+  int Opcode = MI->getOpcode();
+  bool IsDestroy = Opcode == TII.getCallFrameDestroyOpcode();
+  uint64_t CalleePopAmount = IsDestroy ? MI->getOperand(1).getImm() : 0;
+
+  if (!TFI->hasReservedCallFrame(MF)) {
+    unsigned Align = TFI->getStackAlignment();
+
+    uint64_t Amount = MI->getOperand(0).getImm();
+    Amount = (Amount + Align - 1)/Align * Align;
+    if (!IsDestroy) Amount = -Amount;
+
+    // N.b. if CalleePopAmount is valid but zero (i.e. callee would pop, but it
+    // doesn't have to pop anything), then the first operand will be zero too so
+    // this adjustment is a no-op.
+    if (CalleePopAmount == 0) {
+      // FIXME: in-function stack adjustment for calls is limited to 12-bits
+      // because there's no guaranteed temporary register available. Mostly call
+      // frames will be allocated at the start of a function so this is OK, but
+      // it is a limitation that needs dealing with.
+      assert(abs(Amount) < 0xfff && "call frame too large");
+      emitSPUpdate(MBB, MI, dl, TII, AArch64::NoRegister, Amount);
+    }
+  } else if (CalleePopAmount != 0) {
+    // If the calling convention demands that the callee pops arguments from the
+    // stack, we want to add it back if we have a reserved call frame.
+    assert(CalleePopAmount < 0xfff && "call frame too large");
+    emitSPUpdate(MBB, MI, dl, TII, AArch64::NoRegister, -CalleePopAmount);
+  }
+
+  MBB.erase(MI);
+}
+
+unsigned
+AArch64RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
+  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+
+  if (TFI->hasFP(MF))
+    return AArch64::X29;
+  else
+    return AArch64::XSP;
+}
+
+bool
+AArch64RegisterInfo::useFPForScavengingIndex(const MachineFunction &MF) const {
+  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+  const AArch64FrameLowering *AFI = static_cast<const AArch64FrameLowering*>(TFI);
+  return AFI->useFPForAddressing(MF);
+}