ARM64: initial backend import

This adds a second implementation of the AArch64 architecture to LLVM,
accessible in parallel via the "arm64" triple. The plan over the
coming weeks & months is to merge the two into a single backend,
during which time thorough code review should naturally occur.

Everything will be easier with the target in-tree though, hence this
commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205090 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 52 insertions, 0 deletions

diff --git a/lib/Target/ARM64/ARM64TargetObjectFile.cpp b/lib/Target/ARM64/ARM64TargetObjectFile.cpp
new file mode 100644
index 0000000000..cde01e515d
--- /dev/null
+++ b/lib/Target/ARM64/ARM64TargetObjectFile.cpp
@@ -0,0 +1,52 @@
+//===-- ARM64TargetObjectFile.cpp - ARM64 Object Info ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ARM64TargetObjectFile.h"
+#include "ARM64TargetMachine.h"
+#include "llvm/IR/Mangler.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/Support/Dwarf.h"
+using namespace llvm;
+using namespace dwarf;
+
+void ARM64_ELFTargetObjectFile::Initialize(MCContext &Ctx,
+                                           const TargetMachine &TM) {
+  TargetLoweringObjectFileELF::Initialize(Ctx, TM);
+  InitializeELF(TM.Options.UseInitArray);
+}
+
+const MCExpr *ARM64_MachoTargetObjectFile::getTTypeGlobalReference(
+    const GlobalValue *GV, unsigned Encoding, Mangler &Mang,
+    const TargetMachine &TM, MachineModuleInfo *MMI,
+    MCStreamer &Streamer) const {
+  // On Darwin, we can reference dwarf symbols with foo@GOT-., which
+  // is an indirect pc-relative reference. The default implementation
+  // won't reference using the GOT, so we need this target-specific
+  // version.
+  if (Encoding & (DW_EH_PE_indirect | DW_EH_PE_pcrel)) {
+    const MCSymbol *Sym = TM.getSymbol(GV, Mang);
+    const MCExpr *Res =
+        MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_GOT, getContext());
+    MCSymbol *PCSym = getContext().CreateTempSymbol();
+    Streamer.EmitLabel(PCSym);
+    const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, getContext());
+    return MCBinaryExpr::CreateSub(Res, PC, getContext());
+  }
+
+  return TargetLoweringObjectFileMachO::getTTypeGlobalReference(
+      GV, Encoding, Mang, TM, MMI, Streamer);
+}
+
+MCSymbol *ARM64_MachoTargetObjectFile::getCFIPersonalitySymbol(
+    const GlobalValue *GV, Mangler &Mang, const TargetMachine &TM,
+    MachineModuleInfo *MMI) const {
+  return TM.getSymbol(GV, Mang);
+}