Add AArch64 as an experimental target.

This patch adds support for AArch64 (ARM's 64-bit architecture) to
LLVM in the "experimental" category. Currently, it won't be built
unless requested explicitly.

This initial commit should have support for:
    + Assembly of all scalar (i.e. non-NEON, non-Crypto) instructions
      (except the late addition CRC instructions).
    + CodeGen features required for C++03 and C99.
    + Compilation for the "small" memory model: code+static data <
      4GB.
    + Absolute and position-independent code.
    + GNU-style (i.e. "__thread") TLS.
    + Debugging information.

The principal omission, currently, is performance tuning.

This patch excludes the NEON support also reviewed due to an outbreak of
batshit insanity in our legal department. That will be committed soon bringing
the changes to precisely what has been approved.

Further reviews would be gratefully received.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174054 91177308-0d34-0410-b5e6-96231b3b80d8

72 files changed, 22640 insertions, 2 deletions

diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp
index e5b749e28b..c4c8e6e4e7 100644
--- a/lib/MC/MCELFStreamer.cpp
+++ b/lib/MC/MCELFStreamer.cpp
@@ -300,7 +300,9 @@ void MCELFStreamer::EmitFileDirective(StringRef Filename) {
 
 void  MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) {
   switch (expr->getKind()) {
-  case MCExpr::Target: llvm_unreachable("Can't handle target exprs yet!");
+  case MCExpr::Target:
+    cast<MCTargetExpr>(expr)->fixELFSymbolsInTLSFixups(getAssembler());
+    break;
   case MCExpr::Constant:
     break;
 
diff --git a/lib/MC/MCObjectFileInfo.cpp b/lib/MC/MCObjectFileInfo.cpp
index 1f5548f779..ae0abde86a 100644
--- a/lib/MC/MCObjectFileInfo.cpp
+++ b/lib/MC/MCObjectFileInfo.cpp
@@ -256,6 +256,25 @@ void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
       TTypeEncoding = (CMModel == CodeModel::Small)
         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
     }
+  }  else if (T.getArch() ==  Triple::aarch64) {
+    FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
+
+    // The small model guarantees static code/data size < 4GB, but not where it
+    // will be in memory. Most of these could end up >2GB away so even a signed
+    // pc-relative 32-bit address is insufficient, theoretically.
+    if (RelocM == Reloc::PIC_) {
+      PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
+        dwarf::DW_EH_PE_sdata8;
+      LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
+      FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
+      TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
+        dwarf::DW_EH_PE_sdata8;
+    } else {
+      PersonalityEncoding = dwarf::DW_EH_PE_absptr;
+      LSDAEncoding = dwarf::DW_EH_PE_absptr;
+      FDEEncoding = dwarf::DW_EH_PE_udata4;
+      TTypeEncoding = dwarf::DW_EH_PE_absptr;
+    }
   } else if (T.getArch() == Triple::ppc64) {
     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
       dwarf::DW_EH_PE_udata8;
diff --git a/lib/Support/Triple.cpp b/lib/Support/Triple.cpp
index ad7b18942e..d2508ac1ef 100644
--- a/lib/Support/Triple.cpp
+++ b/lib/Support/Triple.cpp
@@ -19,6 +19,7 @@ const char *Triple::getArchTypeName(ArchType Kind) {
   switch (Kind) {
   case UnknownArch: return "unknown";
 
+  case aarch64: return "aarch64";
   case arm:     return "arm";
   case hexagon: return "hexagon";
   case mips:    return "mips";
@@ -53,6 +54,8 @@ const char *Triple::getArchTypePrefix(ArchType Kind) {
   default:
     return 0;
 
+  case aarch64: return "aarch64";
+
   case arm:
   case thumb:   return "arm";
 
@@ -152,6 +155,7 @@ const char *Triple::getEnvironmentTypeName(EnvironmentType Kind) {
 
 Triple::ArchType Triple::getArchTypeForLLVMName(StringRef Name) {
   return StringSwitch<Triple::ArchType>(Name)
+    .Case("aarch64", aarch64)
     .Case("arm", arm)
     .Case("mips", mips)
     .Case("mipsel", mipsel)
@@ -215,6 +219,7 @@ static Triple::ArchType parseArch(StringRef ArchName) {
     .Case("powerpc", Triple::ppc)
     .Cases("powerpc64", "ppu", Triple::ppc64)
     .Case("mblaze", Triple::mblaze)
+    .Case("aarch64", Triple::aarch64)
     .Cases("arm", "xscale", Triple::arm)
     // FIXME: It would be good to replace these with explicit names for all the
     // various suffixes supported.
@@ -676,6 +681,7 @@ static unsigned getArchPointerBitWidth(llvm::Triple::ArchType Arch) {
   case llvm::Triple::spir:
     return 32;
 
+  case llvm::Triple::aarch64:
   case llvm::Triple::mips64:
   case llvm::Triple::mips64el:
   case llvm::Triple::nvptx64:
@@ -704,6 +710,7 @@ Triple Triple::get32BitArchVariant() const {
   Triple T(*this);
   switch (getArch()) {
   case Triple::UnknownArch:
+  case Triple::aarch64:
   case Triple::msp430:
     T.setArch(UnknownArch);
     break;
@@ -755,6 +762,7 @@ Triple Triple::get64BitArchVariant() const {
     T.setArch(UnknownArch);
     break;
 
+  case Triple::aarch64:
   case Triple::spir64:
   case Triple::mips64:
   case Triple::mips64el:
diff --git a/lib/Target/AArch64/AArch64.h b/lib/Target/AArch64/AArch64.h
new file mode 100644
index 0000000000..622814ddfd
--- /dev/null
+++ b/lib/Target/AArch64/AArch64.h
@@ -0,0 +1,42 @@
+//==-- AArch64.h - Top-level interface for AArch64 representation -*- 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 entry points for global functions defined in the LLVM
+// AArch64 back-end.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TARGET_AARCH64_H
+#define LLVM_TARGET_AARCH64_H
+
+#include "MCTargetDesc/AArch64MCTargetDesc.h"
+#include "llvm/Target/TargetMachine.h"
+
+namespace llvm {
+
+class AArch64AsmPrinter;
+class FunctionPass;
+class AArch64TargetMachine;
+class MachineInstr;
+class MCInst;
+
+FunctionPass *createAArch64ISelDAG(AArch64TargetMachine &TM,
+                                   CodeGenOpt::Level OptLevel);
+
+FunctionPass *createAArch64ConstantIslandPass();
+
+FunctionPass *createAArch64CleanupLocalDynamicTLSPass();
+
+void LowerAArch64MachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
+                                      AArch64AsmPrinter &AP);
+
+
+}
+
+#endif
diff --git a/lib/Target/AArch64/AArch64.td b/lib/Target/AArch64/AArch64.td
new file mode 100644
index 0000000000..750fec7931
--- /dev/null
+++ b/lib/Target/AArch64/AArch64.td
@@ -0,0 +1,68 @@
+//===- AArch64.td - Describe the AArch64 Target Machine ---------*- tblgen -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This is the top level entry point for the AArch64 target.
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Target-independent interfaces
+//===----------------------------------------------------------------------===//
+
+include "llvm/Target/Target.td"
+
+//===----------------------------------------------------------------------===//
+// AArch64 Subtarget features.
+//
+
+def FeatureNEON : SubtargetFeature<"neon", "HasNEON", "true",
+  "Enable Advanced SIMD instructions">;
+
+def FeatureCrypto : SubtargetFeature<"crypto", "HasCrypto", "true",
+  "Enable cryptographic instructions">;
+
+//===----------------------------------------------------------------------===//
+// AArch64 Processors
+//
+
+include "AArch64Schedule.td"
+
+def : Processor<"generic", GenericItineraries, [FeatureNEON, FeatureCrypto]>;
+
+//===----------------------------------------------------------------------===//
+// Register File Description
+//===----------------------------------------------------------------------===//
+
+include "AArch64RegisterInfo.td"
+
+include "AArch64CallingConv.td"
+
+//===----------------------------------------------------------------------===//
+// Instruction Descriptions
+//===----------------------------------------------------------------------===//
+
+include "AArch64InstrInfo.td"
+
+def AArch64InstrInfo : InstrInfo;
+
+//===----------------------------------------------------------------------===//
+// Assembly printer
+//===----------------------------------------------------------------------===//
+
+def A64InstPrinter : AsmWriter {
+  string AsmWriterClassName = "InstPrinter";
+  bit isMCAsmWriter = 1;
+}
+
+//===----------------------------------------------------------------------===//
+// Declare the target which we are implementing
+//===----------------------------------------------------------------------===//
+
+def AArch64 : Target {
+  let InstructionSet = AArch64InstrInfo;
+  let AssemblyWriters = [A64InstPrinter];
+}
diff --git a/lib/Target/AArch64/AArch64AsmPrinter.cpp b/lib/Target/AArch64/AArch64AsmPrinter.cpp
new file mode 100644
index 0000000000..63cc88f815
--- /dev/null
+++ b/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -0,0 +1,361 @@
+//===-- AArch64AsmPrinter.cpp - Print machine code to an AArch64 .s file --===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains a printer that converts from our internal representation
+// of machine-dependent LLVM code to GAS-format AArch64 assembly language.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "asm-printer"
+#include "AArch64AsmPrinter.h"
+#include "InstPrinter/AArch64InstPrinter.h"
+#include "llvm/DebugInfo.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineModuleInfoImpls.h"
+#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Target/Mangler.h"
+
+using namespace llvm;
+
+MachineLocation
+AArch64AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const {
+  // See emitFrameIndexDebugValue in InstrInfo for where this instruction is
+  // expected to be created.
+  assert(MI->getNumOperands() == 4 && MI->getOperand(0).isReg()
+         && MI->getOperand(1).isImm() && "unexpected custom DBG_VALUE");
+  return MachineLocation(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
+}
+
+/// Try to print a floating-point register as if it belonged to a specified
+/// register-class. For example the inline asm operand modifier "b" requires its
+/// argument to be printed as "bN".
+static bool printModifiedFPRAsmOperand(const MachineOperand &MO,
+                                       const TargetRegisterInfo *TRI,
+                                       const TargetRegisterClass &RegClass,
+                                       raw_ostream &O) {
+  if (!MO.isReg())
+    return true;
+
+  for (MCRegAliasIterator AR(MO.getReg(), TRI, true); AR.isValid(); ++AR) {
+    if (RegClass.contains(*AR)) {
+      O << AArch64InstPrinter::getRegisterName(*AR);
+      return false;
+    }
+  }
+  return true;
+}
+
+/// Implements the 'w' and 'x' inline asm operand modifiers, which print a GPR
+/// with the obvious type and an immediate 0 as either wzr or xzr.
+static bool printModifiedGPRAsmOperand(const MachineOperand &MO,
+                                       const TargetRegisterInfo *TRI,
+                                       const TargetRegisterClass &RegClass,
+                                       raw_ostream &O) {
+  char Prefix = &RegClass == &AArch64::GPR32RegClass ? 'w' : 'x';
+
+  if (MO.isImm() && MO.getImm() == 0) {
+    O << Prefix << "zr";
+    return false;
+  } else if (MO.isReg()) {
+    if (MO.getReg() == AArch64::XSP || MO.getReg() == AArch64::WSP) {
+      O << (Prefix == 'x' ? "sp" : "wsp");
+      return false;
+    }
+
+    for (MCRegAliasIterator AR(MO.getReg(), TRI, true); AR.isValid(); ++AR) {
+      if (RegClass.contains(*AR)) {
+        O << AArch64InstPrinter::getRegisterName(*AR);
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
+bool AArch64AsmPrinter::printSymbolicAddress(const MachineOperand &MO,
+                                             bool PrintImmediatePrefix,
+                                             StringRef Suffix, raw_ostream &O) {
+  StringRef Name;
+  StringRef Modifier;
+  switch (MO.getType()) {
+  default: llvm_unreachable("Unexpected operand for symbolic address constraint");
+  case MachineOperand::MO_GlobalAddress:
+    Name = Mang->getSymbol(MO.getGlobal())->getName();
+
+    // Global variables may be accessed either via a GOT or in various fun and
+    // interesting TLS-model specific ways. Set the prefix modifier as
+    // appropriate here.
+    if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(MO.getGlobal())) {
+      Reloc::Model RelocM = TM.getRelocationModel();
+      if (GV->isThreadLocal()) {
+        switch (TM.getTLSModel(GV)) {
+        case TLSModel::GeneralDynamic:
+          Modifier = "tlsdesc";
+          break;
+        case TLSModel::LocalDynamic:
+          Modifier = "dtprel";
+          break;
+        case TLSModel::InitialExec:
+          Modifier = "gottprel";
+          break;
+        case TLSModel::LocalExec:
+          Modifier = "tprel";
+          break;
+        }
+      } else if (Subtarget->GVIsIndirectSymbol(GV, RelocM)) {
+        Modifier = "got";
+      }
+    }
+    break;
+  case MachineOperand::MO_BlockAddress:
+    Name = GetBlockAddressSymbol(MO.getBlockAddress())->getName();
+    break;
+  case MachineOperand::MO_ExternalSymbol:
+    Name = MO.getSymbolName();
+    break;
+  case MachineOperand::MO_ConstantPoolIndex:
+    Name = GetCPISymbol(MO.getIndex())->getName();
+    break;
+  }
+
+  // Some instructions (notably ADRP) don't take the # prefix for
+  // immediates. Only print it if asked to.
+  if (PrintImmediatePrefix)
+    O << '#';
+
+  // Only need the joining "_" if both the prefix and the suffix are
+  // non-null. This little block simply takes care of the four possibly
+  // combinations involved there.
+  if (Modifier == "" && Suffix == "")
+    O << Name;
+  else if (Modifier == "" && Suffix != "")
+    O << ":" << Suffix << ':' << Name;
+  else if (Modifier != "" && Suffix == "")
+    O << ":" << Modifier << ':' << Name;
+  else
+    O << ":" << Modifier << '_' << Suffix << ':' << Name;
+
+  return false;
+}
+
+bool AArch64AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
+                                        unsigned AsmVariant,
+                                        const char *ExtraCode, raw_ostream &O) {
+  const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo();
+  if (!ExtraCode || !ExtraCode[0]) {
+    // There's actually no operand modifier, which leads to a slightly eclectic
+    // set of behaviour which we have to handle here.
+    const MachineOperand &MO = MI->getOperand(OpNum);
+    switch (MO.getType()) {
+    default:
+      llvm_unreachable("Unexpected operand for inline assembly");
+    case MachineOperand::MO_Register:
+      // GCC prints