Imported Upstream version 5.18.0.205

Former-commit-id: 7f59f7e792705db773f1caecdaa823092f4e2927

external/llvm/lib/Target/ARC/ARCRegisterInfo.cpp

@@ -0,0 +1,232 @@
+//===- ARCRegisterInfo.cpp - ARC 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 ARC implementation of the MRegisterInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ARCRegisterInfo.h"
+#include "ARC.h"
+#include "ARCInstrInfo.h"
+#include "ARCMachineFunctionInfo.h"
+#include "ARCSubtarget.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/CodeGen/TargetFrameLowering.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "arc-reg-info"
+
+#define GET_REGINFO_TARGET_DESC
+#include "ARCGenRegisterInfo.inc"
+
+static void ReplaceFrameIndex(MachineBasicBlock::iterator II,
+                              const ARCInstrInfo &TII, unsigned Reg,
+                              unsigned FrameReg, int Offset, int StackSize,
+                              int ObjSize, RegScavenger *RS, int SPAdj) {
+  assert(RS && "Need register scavenger.");
+  MachineInstr &MI = *II;
+  MachineBasicBlock &MBB = *MI.getParent();
+  DebugLoc dl = MI.getDebugLoc();
+  unsigned BaseReg = FrameReg;
+  unsigned KillState = 0;
+  if (MI.getOpcode() == ARC::LD_rs9 && (Offset >= 256 || Offset < -256)) {
+    // Loads can always be reached with LD_rlimm.
+    BuildMI(MBB, II, dl, TII.get(ARC::LD_rlimm), Reg)
+        .addReg(BaseReg)
+        .addImm(Offset)
+        .addMemOperand(*MI.memoperands_begin());
+    MBB.erase(II);
+    return;
+  }
+
+  if (MI.getOpcode() != ARC::GETFI && (Offset >= 256 || Offset < -256)) {
+    // We need to use a scratch register to reach the far-away frame indexes.
+    BaseReg = RS->FindUnusedReg(&ARC::GPR32RegClass);
+    if (!BaseReg) {
+      // We can be sure that the scavenged-register slot is within the range
+      // of the load offset.
+      const TargetRegisterInfo *TRI =
+          MBB.getParent()->getSubtarget().getRegisterInfo();
+      BaseReg = RS->scavengeRegister(&ARC::GPR32RegClass, II, SPAdj);
+      assert(BaseReg && "Register scavenging failed.");
+      DEBUG(dbgs() << "Scavenged register " << printReg(BaseReg, TRI)
+                   << " for FrameReg=" << printReg(FrameReg, TRI)
+                   << "+Offset=" << Offset << "\n");
+      (void)TRI;
+      RS->setRegUsed(BaseReg);
+    }
+    unsigned AddOpc = isUInt<6>(Offset) ? ARC::ADD_rru6 : ARC::ADD_rrlimm;
+    BuildMI(MBB, II, dl, TII.get(AddOpc))
+        .addReg(BaseReg, RegState::Define)
+        .addReg(FrameReg)
+        .addImm(Offset);
+    Offset = 0;
+    KillState = RegState::Kill;
+  }
+  switch (MI.getOpcode()) {
+  case ARC::LD_rs9:
+    assert((Offset % 4 == 0) && "LD needs 4 byte alignment.");
+  case ARC::LDH_rs9:
+  case ARC::LDH_X_rs9:
+    assert((Offset % 2 == 0) && "LDH needs 2 byte alignment.");
+  case ARC::LDB_rs9:
+  case ARC::LDB_X_rs9:
+    DEBUG(dbgs() << "Building LDFI\n");
+    BuildMI(MBB, II, dl, TII.get(MI.getOpcode()), Reg)
+        .addReg(BaseReg, KillState)
+        .addImm(Offset)
+        .addMemOperand(*MI.memoperands_begin());
+    break;
+  case ARC::ST_rs9:
+    assert((Offset % 4 == 0) && "ST needs 4 byte alignment.");
+  case ARC::STH_rs9:
+    assert((Offset % 2 == 0) && "STH needs 2 byte alignment.");
+  case ARC::STB_rs9:
+    DEBUG(dbgs() << "Building STFI\n");
+    BuildMI(MBB, II, dl, TII.get(MI.getOpcode()))
+        .addReg(Reg, getKillRegState(MI.getOperand(0).isKill()))
+        .addReg(BaseReg, KillState)
+        .addImm(Offset)
+        .addMemOperand(*MI.memoperands_begin());
+    break;
+  case ARC::GETFI:
+    DEBUG(dbgs() << "Building GETFI\n");
+    BuildMI(MBB, II, dl,
+            TII.get(isUInt<6>(Offset) ? ARC::ADD_rru6 : ARC::ADD_rrlimm))
+        .addReg(Reg, RegState::Define)
+        .addReg(FrameReg)
+        .addImm(Offset);
+    break;
+  default:
+    llvm_unreachable("Unhandled opcode.");
+  }
+
+  // Erase old instruction.
+  MBB.erase(II);
+}
+
+ARCRegisterInfo::ARCRegisterInfo() : ARCGenRegisterInfo(ARC::BLINK) {}
+
+bool ARCRegisterInfo::needsFrameMoves(const MachineFunction &MF) {
+  return MF.getMMI().hasDebugInfo() || MF.getFunction().needsUnwindTableEntry();
+}
+
+const MCPhysReg *
+ARCRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
+  return CSR_ARC_SaveList;
+}
+
+BitVector ARCRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
+  BitVector Reserved(getNumRegs());
+
+  Reserved.set(ARC::ILINK);
+  Reserved.set(ARC::SP);
+  Reserved.set(ARC::GP);
+  Reserved.set(ARC::R25);
+  Reserved.set(ARC::BLINK);
+  Reserved.set(ARC::FP);
+  return Reserved;
+}
+
+bool ARCRegisterInfo::requiresRegisterScavenging(
+    const MachineFunction &MF) const {
+  return true;
+}
+
+bool ARCRegisterInfo::trackLivenessAfterRegAlloc(
+    const MachineFunction &MF) const {
+  return true;
+}
+
+bool ARCRegisterInfo::useFPForScavengingIndex(const MachineFunction &MF) const {
+  return true;
+}
+
+void ARCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
+                                          int SPAdj, unsigned FIOperandNum,
+                                          RegScavenger *RS) const {
+  assert(SPAdj == 0 && "Unexpected");
+  MachineInstr &MI = *II;
+  MachineOperand &FrameOp = MI.getOperand(FIOperandNum);
+  int FrameIndex = FrameOp.getIndex();
+
+  MachineFunction &MF = *MI.getParent()->getParent();
+  const ARCInstrInfo &TII = *MF.getSubtarget<ARCSubtarget>().getInstrInfo();
+  const ARCFrameLowering *TFI = getFrameLowering(MF);
+  int Offset = MF.getFrameInfo().getObjectOffset(FrameIndex);
+  int ObjSize = MF.getFrameInfo().getObjectSize(FrameIndex);
+  int StackSize = MF.getFrameInfo().getStackSize();
+  int LocalFrameSize = MF.getFrameInfo().getLocalFrameSize();
+
+  DEBUG(dbgs() << "\nFunction         : " << MF.getName() << "\n");
+  DEBUG(dbgs() << "<--------->\n");
+  DEBUG(dbgs() << MI << "\n");
+  DEBUG(dbgs() << "FrameIndex         : " << FrameIndex << "\n");
+  DEBUG(dbgs() << "ObjSize            : " << ObjSize << "\n");
+  DEBUG(dbgs() << "FrameOffset        : " << Offset << "\n");
+  DEBUG(dbgs() << "StackSize          : " << StackSize << "\n");
+  DEBUG(dbgs() << "LocalFrameSize     : " << LocalFrameSize << "\n");
+  (void)LocalFrameSize;
+
+  // Special handling of DBG_VALUE instructions.
+  if (MI.isDebugValue()) {
+    unsigned FrameReg = getFrameRegister(MF);
+    MI.getOperand(FIOperandNum).ChangeToRegister(FrameReg, false /*isDef*/);
+    MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
+    return;
+  }
+
+  // fold constant into offset.
+  Offset += MI.getOperand(FIOperandNum + 1).getImm();
+
+  // TODO: assert based on the load type:
+  // ldb needs no alignment,
+  // ldh needs 2 byte alignment
+  // ld needs 4 byte alignment
+  DEBUG(dbgs() << "Offset             : " << Offset << "\n"
+               << "<--------->\n");
+
+  unsigned Reg = MI.getOperand(0).getReg();
+  assert(ARC::GPR32RegClass.contains(Reg) && "Unexpected register operand");
+
+  if (!TFI->hasFP(MF)) {
+    Offset = StackSize + Offset;
+    if (FrameIndex >= 0)
+      assert((Offset >= 0 && Offset < StackSize) && "SP Offset not in bounds.");
+  } else {
+    if (FrameIndex >= 0) {
+      assert((Offset < 0 && -Offset <= StackSize) &&
+             "FP Offset not in bounds.");
+    }
+  }
+  ReplaceFrameIndex(II, TII, Reg, getFrameRegister(MF), Offset, StackSize,
+                    ObjSize, RS, SPAdj);
+}
+
+unsigned ARCRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
+  const ARCFrameLowering *TFI = getFrameLowering(MF);
+  return TFI->hasFP(MF) ? ARC::FP : ARC::SP;
+}
+
+const uint32_t *
+ARCRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
+                                      CallingConv::ID CC) const {
+  return CSR_ARC_RegMask;
+}