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.

llvm-svn: 174054

1 files changed, 287 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
new file mode 100644
index 00000000000..476b94e70fe
--- /dev/null
+++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
@@ -0,0 +1,287 @@
+//===-- AArch64ELFObjectWriter.cpp - AArch64 ELF Writer -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MCTargetDesc/AArch64FixupKinds.h"
+#include "MCTargetDesc/AArch64MCTargetDesc.h"
+#include "llvm/MC/MCELFObjectWriter.h"
+#include "llvm/MC/MCValue.h"
+#include "llvm/Support/ErrorHandling.h"
+
+using namespace llvm;
+
+namespace {
+class AArch64ELFObjectWriter : public MCELFObjectTargetWriter {
+public:
+  AArch64ELFObjectWriter(uint8_t OSABI);
+
+  virtual ~AArch64ELFObjectWriter();
+
+protected:
+  virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
+                                bool IsPCRel, bool IsRelocWithSymbol,
+                                int64_t Addend) const;
+private:
+};
+}
+
+AArch64ELFObjectWriter::AArch64ELFObjectWriter(uint8_t OSABI)
+  : MCELFObjectTargetWriter(/*Is64Bit*/ true, OSABI, ELF::EM_AARCH64,
+                            /*HasRelocationAddend*/ true)
+{}
+
+AArch64ELFObjectWriter::~AArch64ELFObjectWriter()
+{}
+
+unsigned AArch64ELFObjectWriter::GetRelocType(const MCValue &Target,
+                                              const MCFixup &Fixup,
+                                              bool IsPCRel,
+                                              bool IsRelocWithSymbol,
+                                              int64_t Addend) const {
+  unsigned Type;
+  if (IsPCRel) {
+    switch ((unsigned)Fixup.getKind()) {
+    default:
+      llvm_unreachable("Unimplemented fixup -> relocation");
+    case FK_Data_8:
+      return ELF::R_AARCH64_PREL64;
+    case FK_Data_4:
+      return ELF::R_AARCH64_PREL32;
+    case FK_Data_2:
+      return ELF::R_AARCH64_PREL16;
+    case AArch64::fixup_a64_ld_prel:
+      Type = ELF::R_AARCH64_LD_PREL_LO19;
+      break;
+    case AArch64::fixup_a64_adr_prel:
+      Type = ELF::R_AARCH64_ADR_PREL_LO21;
+      break;
+    case AArch64::fixup_a64_adr_prel_page:
+      Type = ELF::R_AARCH64_ADR_PREL_PG_HI21;
+      break;
+    case AArch64::fixup_a64_adr_prel_got_page:
+      Type = ELF::R_AARCH64_ADR_GOT_PAGE;
+      break;
+    case AArch64::fixup_a64_tstbr:
+      Type = ELF::R_AARCH64_TSTBR14;
+      break;
+    case AArch64::fixup_a64_condbr:
+      Type = ELF::R_AARCH64_CONDBR19;
+      break;
+    case AArch64::fixup_a64_uncondbr:
+      Type = ELF::R_AARCH64_JUMP26;
+      break;
+    case AArch64::fixup_a64_call:
+      Type = ELF::R_AARCH64_CALL26;
+      break;
+    case AArch64::fixup_a64_adr_gottprel_page:
+      Type = ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21;
+      break;
+    case AArch64::fixup_a64_ld_gottprel_prel19:
+      Type =  ELF::R_AARCH64_TLSIE_LD_GOTTPREL_PREL19;
+      break;
+    case AArch64::fixup_a64_tlsdesc_adr_page:
+      Type = ELF::R_AARCH64_TLSDESC_ADR_PAGE;
+      break;
+    }
+  } else {
+    switch ((unsigned)Fixup.getKind()) {
+    default:
+      llvm_unreachable("Unimplemented fixup -> relocation");
+    case FK_Data_8:
+      return ELF::R_AARCH64_ABS64;
+    case FK_Data_4:
+      return ELF::R_AARCH64_ABS32;
+    case FK_Data_2:
+      return ELF::R_AARCH64_ABS16;
+    case AArch64::fixup_a64_add_lo12:
+      Type = ELF::R_AARCH64_ADD_ABS_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ld64_got_lo12_nc:
+      Type = ELF::R_AARCH64_LD64_GOT_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst8_lo12:
+      Type = ELF::R_AARCH64_LDST8_ABS_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst16_lo12:
+      Type = ELF::R_AARCH64_LDST16_ABS_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst32_lo12:
+      Type = ELF::R_AARCH64_LDST32_ABS_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst64_lo12:
+      Type = ELF::R_AARCH64_LDST64_ABS_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst128_lo12:
+      Type = ELF::R_AARCH64_LDST128_ABS_LO12_NC;
+      break;
+    case AArch64::fixup_a64_movw_uabs_g0:
+      Type = ELF::R_AARCH64_MOVW_UABS_G0;
+      break;
+    case AArch64::fixup_a64_movw_uabs_g0_nc:
+      Type = ELF::R_AARCH64_MOVW_UABS_G0_NC;
+      break;
+    case AArch64::fixup_a64_movw_uabs_g1:
+      Type = ELF::R_AARCH64_MOVW_UABS_G1;
+      break;
+    case AArch64::fixup_a64_movw_uabs_g1_nc:
+      Type = ELF::R_AARCH64_MOVW_UABS_G1_NC;
+      break;
+    case AArch64::fixup_a64_movw_uabs_g2:
+      Type = ELF::R_AARCH64_MOVW_UABS_G2;
+      break;
+    case AArch64::fixup_a64_movw_uabs_g2_nc:
+      Type = ELF::R_AARCH64_MOVW_UABS_G2_NC;
+      break;
+    case AArch64::fixup_a64_movw_uabs_g3:
+      Type = ELF::R_AARCH64_MOVW_UABS_G3;
+      break;
+    case AArch64::fixup_a64_movw_sabs_g0:
+      Type = ELF::R_AARCH64_MOVW_SABS_G0;
+      break;
+    case AArch64::fixup_a64_movw_sabs_g1:
+      Type = ELF::R_AARCH64_MOVW_SABS_G1;
+      break;
+    case AArch64::fixup_a64_movw_sabs_g2:
+      Type = ELF::R_AARCH64_MOVW_SABS_G2;
+      break;
+
+    // TLS Local-dynamic block
+    case AArch64::fixup_a64_movw_dtprel_g2:
+      Type = ELF::R_AARCH64_TLSLD_MOVW_DTPREL_G2;
+      break;
+    case AArch64::fixup_a64_movw_dtprel_g1:
+      Type = ELF::R_AARCH64_TLSLD_MOVW_DTPREL_G1;
+      break;
+    case AArch64::fixup_a64_movw_dtprel_g1_nc:
+      Type = ELF::R_AARCH64_TLSLD_MOVW_DTPREL_G1_NC;
+      break;
+    case AArch64::fixup_a64_movw_dtprel_g0:
+      Type = ELF::R_AARCH64_TLSLD_MOVW_DTPREL_G0;
+      break;
+    case AArch64::fixup_a64_movw_dtprel_g0_nc:
+      Type = ELF::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC;
+      break;
+    case AArch64::fixup_a64_add_dtprel_hi12:
+      Type = ELF::R_AARCH64_TLSLD_ADD_DTPREL_HI12;
+      break;
+    case AArch64::fixup_a64_add_dtprel_lo12:
+      Type = ELF::R_AARCH64_TLSLD_ADD_DTPREL_LO12;
+      break;
+    case AArch64::fixup_a64_add_dtprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSLD_ADD_DTPREL_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst8_dtprel_lo12:
+      Type = ELF::R_AARCH64_TLSLD_LDST8_DTPREL_LO12;
+      break;
+    case AArch64::fixup_a64_ldst8_dtprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSLD_LDST8_DTPREL_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst16_dtprel_lo12:
+      Type = ELF::R_AARCH64_TLSLD_LDST16_DTPREL_LO12;
+      break;
+    case AArch64::fixup_a64_ldst16_dtprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSLD_LDST16_DTPREL_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst32_dtprel_lo12:
+      Type = ELF::R_AARCH64_TLSLD_LDST32_DTPREL_LO12;
+      break;
+    case AArch64::fixup_a64_ldst32_dtprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSLD_LDST32_DTPREL_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst64_dtprel_lo12:
+      Type = ELF::R_AARCH64_TLSLD_LDST64_DTPREL_LO12;
+      break;
+    case AArch64::fixup_a64_ldst64_dtprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSLD_LDST64_DTPREL_LO12_NC;
+      break;
+
+    // TLS initial-exec block
+    case AArch64::fixup_a64_movw_gottprel_g1:
+      Type = ELF::R_AARCH64_TLSIE_MOVW_GOTTPREL_G1;
+      break;
+    case AArch64::fixup_a64_movw_gottprel_g0_nc:
+      Type = ELF::R_AARCH64_TLSIE_MOVW_GOTTPREL_G0_NC;
+      break;
+    case AArch64::fixup_a64_ld64_gottprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC;
+      break;
+
+    // TLS local-exec block
+    case AArch64::fixup_a64_movw_tprel_g2:
+      Type = ELF::R_AARCH64_TLSLE_MOVW_TPREL_G2;
+      break;
+    case AArch64::fixup_a64_movw_tprel_g1:
+      Type = ELF::R_AARCH64_TLSLE_MOVW_TPREL_G1;
+      break;
+    case AArch64::fixup_a64_movw_tprel_g1_nc:
+      Type = ELF::R_AARCH64_TLSLE_MOVW_TPREL_G1_NC;
+      break;
+    case AArch64::fixup_a64_movw_tprel_g0:
+      Type = ELF::R_AARCH64_TLSLE_MOVW_TPREL_G0;
+      break;
+    case AArch64::fixup_a64_movw_tprel_g0_nc:
+      Type = ELF::R_AARCH64_TLSLE_MOVW_TPREL_G0_NC;
+      break;
+    case AArch64::fixup_a64_add_tprel_hi12:
+      Type = ELF::R_AARCH64_TLSLE_ADD_TPREL_HI12;
+      break;
+    case AArch64::fixup_a64_add_tprel_lo12:
+      Type = ELF::R_AARCH64_TLSLE_ADD_TPREL_LO12;
+      break;
+    case AArch64::fixup_a64_add_tprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst8_tprel_lo12:
+      Type = ELF::R_AARCH64_TLSLE_LDST8_TPREL_LO12;
+      break;
+    case AArch64::fixup_a64_ldst8_tprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSLE_LDST8_TPREL_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst16_tprel_lo12:
+      Type = ELF::R_AARCH64_TLSLE_LDST16_TPREL_LO12;
+      break;
+    case AArch64::fixup_a64_ldst16_tprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSLE_LDST16_TPREL_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst32_tprel_lo12:
+      Type = ELF::R_AARCH64_TLSLE_LDST32_TPREL_LO12;
+      break;
+    case AArch64::fixup_a64_ldst32_tprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSLE_LDST32_TPREL_LO12_NC;
+      break;
+    case AArch64::fixup_a64_ldst64_tprel_lo12:
+      Type = ELF::R_AARCH64_TLSLE_LDST64_TPREL_LO12;
+      break;
+    case AArch64::fixup_a64_ldst64_tprel_lo12_nc:
+      Type = ELF::R_AARCH64_TLSLE_LDST64_TPREL_LO12_NC;
+      break;
+
+    // TLS general-dynamic block
+    case AArch64::fixup_a64_tlsdesc_adr_page:
+      Type = ELF::R_AARCH64_TLSDESC_ADR_PAGE;
+      break;
+    case AArch64::fixup_a64_tlsdesc_ld64_lo12_nc:
+      Type = ELF::R_AARCH64_TLSDESC_LD64_LO12_NC;
+      break;
+    case AArch64::fixup_a64_tlsdesc_add_lo12_nc:
+      Type = ELF::R_AARCH64_TLSDESC_ADD_LO12_NC;
+      break;
+    case AArch64::fixup_a64_tlsdesc_call:
+      Type = ELF::R_AARCH64_TLSDESC_CALL;
+      break;
+    }
+  }
+
+  return Type;
+}
+
+MCObjectWriter *llvm::createAArch64ELFObjectWriter(raw_ostream &OS,
+                                                   uint8_t OSABI) {
+  MCELFObjectTargetWriter *MOTW = new AArch64ELFObjectWriter(OSABI);
+  return createELFObjectWriter(MOTW, OS,  /*IsLittleEndian=*/true);
+}