Hexagon backend support

llvm-svn: 146412

1 files changed, 322 insertions, 0 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonRegisterInfo.cpp b/llvm/lib/Target/Hexagon/HexagonRegisterInfo.cpp
new file mode 100644
index 00000000000..9fd9fd34243
--- /dev/null
+++ b/llvm/lib/Target/Hexagon/HexagonRegisterInfo.cpp
@@ -0,0 +1,322 @@
+//==- HexagonRegisterInfo.cpp - Hexagon Register Information -----*- C++ -*-==//
+//
+//                     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 Hexagon implementation of the TargetRegisterInfo
+// class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Hexagon.h"
+#include "HexagonRegisterInfo.h"
+#include "HexagonSubtarget.h"
+#include "HexagonTargetMachine.h"
+#include "HexagonMachineFunctionInfo.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/MC/MachineLocation.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Type.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include <iostream>
+
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/Function.h"
+using namespace llvm;
+
+
+HexagonRegisterInfo::HexagonRegisterInfo(HexagonSubtarget &st,
+                                     const HexagonInstrInfo &tii)
+  : HexagonGenRegisterInfo(Hexagon::R31),
+    Subtarget(st),
+   TII(tii) {
+}
+
+const unsigned* HexagonRegisterInfo::getCalleeSavedRegs(const MachineFunction
+                                                        *MF)
+  const {
+  static const unsigned CalleeSavedRegsV2[] = {
+  Hexagon::R24,   Hexagon::R25,   Hexagon::R26,   Hexagon::R27, 0
+  };
+  static const unsigned CalleeSavedRegsV3[] = {
+    Hexagon::R16,   Hexagon::R17,   Hexagon::R18,   Hexagon::R19,
+    Hexagon::R20,   Hexagon::R21,   Hexagon::R22,   Hexagon::R23,
+    Hexagon::R24,   Hexagon::R25,   Hexagon::R26,   Hexagon::R27, 0
+  };
+
+  switch(Subtarget.getHexagonArchVersion()) {
+  case HexagonSubtarget::V2:
+    return CalleeSavedRegsV2;
+    break;
+  case HexagonSubtarget::V3:
+  case HexagonSubtarget::V4:
+    return CalleeSavedRegsV3;
+    break;
+  default:
+    const char *ErrorString = 
+      "Callee saved registers requested for unknown archtecture version";
+    llvm_unreachable(ErrorString);
+  }
+}
+
+BitVector HexagonRegisterInfo::getReservedRegs(const MachineFunction &MF)
+  const {
+  BitVector Reserved(getNumRegs());
+  Reserved.set(HEXAGON_RESERVED_REG_1);
+  Reserved.set(HEXAGON_RESERVED_REG_2);
+  Reserved.set(Hexagon::R29);
+  Reserved.set(Hexagon::R30);
+  Reserved.set(Hexagon::R31);
+  Reserved.set(Hexagon::D14);
+  Reserved.set(Hexagon::D15);
+  Reserved.set(Hexagon::LC0);
+  Reserved.set(Hexagon::LC1);
+  Reserved.set(Hexagon::SA0);
+  Reserved.set(Hexagon::SA1);
+  return Reserved;
+}
+
+
+const TargetRegisterClass* const*
+HexagonRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
+  static const TargetRegisterClass * const CalleeSavedRegClassesV2[] = {
+    &Hexagon::IntRegsRegClass,     &Hexagon::IntRegsRegClass,
+    &Hexagon::IntRegsRegClass,     &Hexagon::IntRegsRegClass,
+    };
+  static const TargetRegisterClass * const CalleeSavedRegClassesV3[] = {
+    &Hexagon::IntRegsRegClass,     &Hexagon::IntRegsRegClass,
+    &Hexagon::IntRegsRegClass,     &Hexagon::IntRegsRegClass,
+    &Hexagon::IntRegsRegClass,     &Hexagon::IntRegsRegClass,
+    &Hexagon::IntRegsRegClass,     &Hexagon::IntRegsRegClass,
+    &Hexagon::IntRegsRegClass,     &Hexagon::IntRegsRegClass,
+    &Hexagon::IntRegsRegClass,     &Hexagon::IntRegsRegClass,
+  };
+
+  switch(Subtarget.getHexagonArchVersion()) {
+  case HexagonSubtarget::V2:
+    return CalleeSavedRegClassesV2;
+    break;
+  case HexagonSubtarget::V3:
+  case HexagonSubtarget::V4:
+    return CalleeSavedRegClassesV3;
+    break;
+  default:
+    const char *ErrorString = 
+      "Callee saved register classes requested for unknown archtecture version";
+    llvm_unreachable(ErrorString);
+  }
+}
+
+void HexagonRegisterInfo::
+eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+                              MachineBasicBlock::iterator I) const {
+  MachineInstr &MI = *I;
+
+  if (MI.getOpcode() == Hexagon::ADJCALLSTACKDOWN) {
+    // Hexagon_TODO: add code
+  } else if (MI.getOpcode() == Hexagon::ADJCALLSTACKUP) {
+    // Hexagon_TODO: add code
+  } else {
+    assert(0 && "Cannot handle this call frame pseudo instruction");
+  }
+  MBB.erase(I);
+}
+
+void HexagonRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
+                                            int SPAdj, RegScavenger *RS) const {
+
+  //
+  // Hexagon_TODO: Do we need to enforce this for Hexagon?
+  assert(SPAdj == 0 && "Unexpected");
+
+
+  unsigned i = 0;
+  MachineInstr &MI = *II;
+  while (!MI.getOperand(i).isFI()) {
+    ++i;
+    assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
+  }
+
+  int FrameIndex = MI.getOperand(i).getIndex();
+
+  // Addressable stack objects are accessed using neg. offsets from %fp.
+  MachineFunction &MF = *MI.getParent()->getParent();
+  int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
+  MachineFrameInfo &MFI = *MF.getFrameInfo();
+
+  unsigned FrameReg = getFrameRegister(MF);
+  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+  if (!TFI->hasFP(MF)) {
+    // We will not reserve space on the stack for the lr and fp registers.
+    Offset -= 2 * Hexagon_WordSize;
+  }
+
+  const unsigned FrameSize = MFI.getStackSize();
+
+  if (!MFI.hasVarSizedObjects() &&
+      TII.isValidOffset(MI.getOpcode(), (FrameSize+Offset)) &&
+      !TII.isSpillPredRegOp(&MI)) {
+    // Replace frame index with a stack pointer reference.
+    MI.getOperand(i).ChangeToRegister(getStackRegister(), false, false, true);
+    MI.getOperand(i+1).ChangeToImmediate(FrameSize+Offset);
+  } else {
+    // Replace frame index with a frame pointer reference.
+    if (!TII.isValidOffset(MI.getOpcode(), Offset)) {
+
+      // If the offset overflows, then correct it.
+      //
+      // For loads, we do not need a reserved register
+      // r0 = memw(r30 + #10000) to:
+      //
+      // r0 = add(r30, #10000)
+      // r0 = memw(r0)
+      if ( (MI.getOpcode() == Hexagon::LDriw)  ||
+           (MI.getOpcode() == Hexagon::LDrid) ||
+           (MI.getOpcode() == Hexagon::LDrih) ||
+           (MI.getOpcode() == Hexagon::LDriuh) ||
+           (MI.getOpcode() == Hexagon::LDrib) ||
+           (MI.getOpcode() == Hexagon::LDriub) ) {
+        unsigned dstReg = (MI.getOpcode() == Hexagon::LDrid) ?
+          *getSubRegisters(MI.getOperand(0).getReg()) :
+          MI.getOperand(0).getReg();
+
+        // Check if offset can fit in addi.
+        if (!TII.isValidOffset(Hexagon::ADD_ri, Offset)) {
+          BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                  TII.get(Hexagon::CONST32_Int_Real), dstReg).addImm(Offset);
+          BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                  TII.get(Hexagon::ADD_rr),
+                  dstReg).addReg(FrameReg).addReg(dstReg);
+        } else {
+          BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                  TII.get(Hexagon::ADD_ri),
+                  dstReg).addReg(FrameReg).addImm(Offset);
+        }
+
+        MI.getOperand(i).ChangeToRegister(dstReg, false, false, true);
+        MI.getOperand(i+1).ChangeToImmediate(0);
+      } else if ((MI.getOpcode() == Hexagon::STriw) ||
+                 (MI.getOpcode() == Hexagon::STrid) ||
+                 (MI.getOpcode() == Hexagon::STrih) ||
+                 (MI.getOpcode() == Hexagon::STrib) ||
+                 (MI.getOpcode() == Hexagon::STriwt)) {
+        // For stores, we need a reserved register. Change
+        // memw(r30 + #10000) = r0 to:
+        //
+        // rs = add(r30, #10000);
+        // memw(rs) = r0
+        unsigned resReg = HEXAGON_RESERVED_REG_1;
+
+        // Check if offset can fit in addi.
+        if (!TII.isValidOffset(Hexagon::ADD_ri, Offset)) {
+          BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                  TII.get(Hexagon::CONST32_Int_Real), resReg).addImm(Offset);
+          BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                  TII.get(Hexagon::ADD_rr),
+                  resReg).addReg(FrameReg).addReg(resReg);
+        } else {
+          BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                  TII.get(Hexagon::ADD_ri),
+                  resReg).addReg(FrameReg).addImm(Offset);
+        }
+        MI.getOperand(i).ChangeToRegister(resReg, false, false, true);
+        MI.getOperand(i+1).ChangeToImmediate(0);
+      } else if (TII.isMemOp(&MI)) {
+        unsigned resReg = HEXAGON_RESERVED_REG_1;
+        if (!MFI.hasVarSizedObjects() &&
+            TII.isValidOffset(MI.getOpcode(), (FrameSize+Offset))) {
+          MI.getOperand(i).ChangeToRegister(getStackRegister(), false, false,
+                                            true);
+          MI.getOperand(i+1).ChangeToImmediate(FrameSize+Offset);
+        } else if (!TII.isValidOffset(Hexagon::ADD_ri, Offset)) {
+          BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                  TII.get(Hexagon::CONST32_Int_Real), resReg).addImm(Offset);
+          BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                  TII.get(Hexagon::ADD_rr),
+                  resReg).addReg(FrameReg).addReg(resReg);
+          MI.getOperand(i).ChangeToRegister(resReg, false, false, true);
+          MI.getOperand(i+1).ChangeToImmediate(0);
+        } else {
+          BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                  TII.get(Hexagon::ADD_ri),
+                  resReg).addReg(FrameReg).addImm(Offset);
+          MI.getOperand(i).ChangeToRegister(resReg, false, false, true);
+          MI.getOperand(i+1).ChangeToImmediate(0);
+        }
+      } else {
+        unsigned dstReg = MI.getOperand(0).getReg();
+        BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                TII.get(Hexagon::CONST32_Int_Real), dstReg).addImm(Offset);
+        BuildMI(*MI.getParent(), II, MI.getDebugLoc(),
+                TII.get(Hexagon::ADD_rr),
+                dstReg).addReg(FrameReg).addReg(dstReg);
+        // Can we delete MI??? r2 = add (r2, #0).
+        MI.getOperand(i).ChangeToRegister(dstReg, false, false, true);
+        MI.getOperand(i+1).ChangeToImmediate(0);
+      }
+    } else {
+      // If the offset is small enough to fit in the immediate field, directly
+      // encode it.
+      MI.getOperand(i).ChangeToRegister(FrameReg, false);
+      MI.getOperand(i+1).ChangeToImmediate(Offset);
+    }
+  }
+
+}
+
+unsigned HexagonRegisterInfo::getRARegister() const {
+  return Hexagon::R31;
+}
+
+unsigned HexagonRegisterInfo::getFrameRegister(const MachineFunction
+                                               &MF) const {
+  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+  if (TFI->hasFP(MF)) {
+    return Hexagon::R30;
+  }
+
+  return Hexagon::R29;
+}
+
+unsigned HexagonRegisterInfo::getFrameRegister() const {
+  return Hexagon::R30;
+}
+
+unsigned HexagonRegisterInfo::getStackRegister() const {
+  return Hexagon::R29;
+}
+
+void HexagonRegisterInfo::getInitialFrameState(std::vector<MachineMove>
+                                               &Moves)  const
+{
+  // VirtualFP = (R30 + #0).
+  unsigned FPReg = getFrameRegister();
+  MachineLocation Dst(MachineLocation::VirtualFP);
+  MachineLocation Src(FPReg, 0);
+  Moves.push_back(MachineMove(0, Dst, Src));
+}
+
+unsigned HexagonRegisterInfo::getEHExceptionRegister() const {
+  assert(0 && "What is the exception register");
+  return 0;
+}
+
+unsigned HexagonRegisterInfo::getEHHandlerRegister() const {
+  assert(0 && "What is the exception handler register");
+  return 0;
+}
+
+#include "HexagonGenRegisterInfo.inc"