1 files changed, 170 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/MBlaze/MCTargetDesc/MBlazeAsmBackend.cpp b/contrib/llvm/lib/Target/MBlaze/MCTargetDesc/MBlazeAsmBackend.cpp
new file mode 100644
index 0000000..f383fec
--- /dev/null
+++ b/contrib/llvm/lib/Target/MBlaze/MCTargetDesc/MBlazeAsmBackend.cpp
@@ -0,0 +1,170 @@
+//===-- MBlazeAsmBackend.cpp - MBlaze Assembler Backend -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MCTargetDesc/MBlazeMCTargetDesc.h"
+#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCAsmLayout.h"
+#include "llvm/MC/MCELFObjectWriter.h"
+#include "llvm/MC/MCELFSymbolFlags.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCSectionMachO.h"
+#include "llvm/MC/MCValue.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/ELF.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+static unsigned getFixupKindSize(unsigned Kind) {
+  switch (Kind) {
+  default: llvm_unreachable("invalid fixup kind!");
+  case FK_Data_1: return 1;
+  case FK_PCRel_2:
+  case FK_Data_2: return 2;
+  case FK_PCRel_4:
+  case FK_Data_4: return 4;
+  case FK_Data_8: return 8;
+  }
+}
+
+
+namespace {
+
+class MBlazeAsmBackend : public MCAsmBackend {
+public:
+  MBlazeAsmBackend(const Target &T)
+    : MCAsmBackend() {
+  }
+
+  unsigned getNumFixupKinds() const {
+    return 2;
+  }
+
+  bool mayNeedRelaxation(const MCInst &Inst) const;
+
+  bool fixupNeedsRelaxation(const MCFixup &Fixup,
+                            uint64_t Value,
+                            const MCInstFragment *DF,
+                            const MCAsmLayout &Layout) const;
+
+  void relaxInstruction(const MCInst &Inst, MCInst &Res) const;
+
+  bool writeNopData(uint64_t Count, MCObjectWriter *OW) const;
+
+  unsigned getPointerSize() const {
+    return 4;
+  }
+};
+
+static unsigned getRelaxedOpcode(unsigned Op) {
+    switch (Op) {
+    default:            return Op;
+    case MBlaze::ADDIK: return MBlaze::ADDIK32;
+    case MBlaze::ORI:   return MBlaze::ORI32;
+    case MBlaze::BRLID: return MBlaze::BRLID32;
+    }
+}
+
+bool MBlazeAsmBackend::mayNeedRelaxation(const MCInst &Inst) const {
+  if (getRelaxedOpcode(Inst.getOpcode()) == Inst.getOpcode())
+    return false;
+
+  bool hasExprOrImm = false;
+  for (unsigned i = 0; i < Inst.getNumOperands(); ++i)
+    hasExprOrImm |= Inst.getOperand(i).isExpr();
+
+  return hasExprOrImm;
+}
+
+bool MBlazeAsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup,
+                                            uint64_t Value,
+                                            const MCInstFragment *DF,
+                                            const MCAsmLayout &Layout) const {
+  // FIXME: Is this right? It's what the "generic" code was doing before,
+  // but is X86 specific. Is it actually true for MBlaze also, or was it
+  // just close enough to not be a big deal?
+  //
+  // Relax if the value is too big for a (signed) i8.
+  return int64_t(Value) != int64_t(int8_t(Value));
+}
+
+void MBlazeAsmBackend::relaxInstruction(const MCInst &Inst, MCInst &Res) const {
+  Res = Inst;
+  Res.setOpcode(getRelaxedOpcode(Inst.getOpcode()));
+}
+
+bool MBlazeAsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const {
+  if ((Count % 4) != 0)
+    return false;
+
+  for (uint64_t i = 0; i < Count; i += 4)
+      OW->Write32(0x00000000);
+
+  return true;
+}
+} // end anonymous namespace
+
+namespace {
+class ELFMBlazeAsmBackend : public MBlazeAsmBackend {
+public:
+  uint8_t OSABI;
+  ELFMBlazeAsmBackend(const Target &T, uint8_t _OSABI)
+    : MBlazeAsmBackend(T), OSABI(_OSABI) { }
+
+  void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
+                  uint64_t Value) const;
+
+  MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
+    return createMBlazeELFObjectWriter(OS, OSABI);
+  }
+};
+
+void ELFMBlazeAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
+                                     unsigned DataSize, uint64_t Value) const {
+  unsigned Size = getFixupKindSize(Fixup.getKind());
+
+  assert(Fixup.getOffset() + Size <= DataSize &&
+         "Invalid fixup offset!");
+
+  char *data = Data + Fixup.getOffset();
+  switch (Size) {
+  default: llvm_unreachable("Cannot fixup unknown value.");
+  case 1:  llvm_unreachable("Cannot fixup 1 byte value.");
+  case 8:  llvm_unreachable("Cannot fixup 8 byte value.");
+
+  case 4:
+    *(data+7) = uint8_t(Value);
+    *(data+6) = uint8_t(Value >> 8);
+    *(data+3) = uint8_t(Value >> 16);
+    *(data+2) = uint8_t(Value >> 24);
+    break;
+
+  case 2:
+    *(data+3) = uint8_t(Value >> 0);
+    *(data+2) = uint8_t(Value >> 8);
+  }
+}
+} // end anonymous namespace
+
+MCAsmBackend *llvm::createMBlazeAsmBackend(const Target &T, StringRef TT) {
+  Triple TheTriple(TT);
+
+  if (TheTriple.isOSDarwin())
+    assert(0 && "Mac not supported on MBlaze");
+
+  if (TheTriple.isOSWindows())
+    assert(0 && "Windows not supported on MBlaze");
+
+  uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TheTriple.getOS());
+  return new ELFMBlazeAsmBackend(T, OSABI);
+}