Major update of the MicroBlaze backend. The new features are:

    1. A delay slot filler that searches for valid instructions
       to fill the delay slot with. Previously NOPs would always
       be inserted into delay slots.
    2. Support for MC based instruction printer added.
    3. Support for MC based machine code generation and ELF
       file generation. ELF file generation does not yet
       completely work as much of the ELF support infrastructure
       is still x86/x86-64 specific.
    4. General clean up of the MBlaze backend code. Much of the
       tablegen code has been cleanup and simplified.

Bug Fixes:
    1. Removed duplicate periods from subtarget feature descriptions.
    2. Many of the instructions had bad machine code information
       in the tablegen files. Much of this has been fixed.

llvm-svn: 116986

1 files changed, 152 insertions, 0 deletions

diff --git a/llvm/lib/Target/MBlaze/MBlazeAsmBackend.cpp b/llvm/lib/Target/MBlaze/MBlazeAsmBackend.cpp
new file mode 100644
index 00000000000..7e11f7371e5
--- /dev/null
+++ b/llvm/lib/Target/MBlaze/MBlazeAsmBackend.cpp
@@ -0,0 +1,152 @@
+//===-- 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 "llvm/Target/TargetAsmBackend.h"
+#include "MBlaze.h"
+#include "MBlazeFixupKinds.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/MC/ELFObjectWriter.h"
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCObjectFormat.h"
+#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCSectionMachO.h"
+#include "llvm/MC/MachObjectWriter.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetRegistry.h"
+#include "llvm/Target/TargetAsmBackend.h"
+using namespace llvm;
+
+static unsigned getFixupKindSize(unsigned Kind) {
+  switch (Kind) {
+  default: assert(0 && "invalid fixup kind!");
+  case FK_Data_1: return 1;
+  case MBlaze::reloc_pcrel_2byte:
+  case FK_Data_2: return 2;
+  case MBlaze::reloc_pcrel_4byte:
+  case FK_Data_4: return 4;
+  case FK_Data_8: return 8;
+  }
+}
+
+
+namespace {
+class MBlazeAsmBackend : public TargetAsmBackend {
+public:
+  MBlazeAsmBackend(const Target &T)
+    : TargetAsmBackend(T) {
+  }
+
+  bool MayNeedRelaxation(const MCInst &Inst) const;
+
+  void RelaxInstruction(const MCInst &Inst, MCInst &Res) const;
+
+  bool WriteNopData(uint64_t Count, MCObjectWriter *OW) const;
+
+  unsigned getPointerSize() const {
+    return 4;
+  }
+};
+
+bool MBlazeAsmBackend::MayNeedRelaxation(const MCInst &Inst) const {
+  return false;
+}
+
+void MBlazeAsmBackend::RelaxInstruction(const MCInst &Inst, MCInst &Res) const {
+  assert(0 && "MBlazeAsmBackend::RelaxInstruction() unimplemented");
+  return;
+}
+
+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 {
+// FIXME: This should be in a separate file.
+// ELF is an ELF of course...
+class ELFMBlazeAsmBackend : public MBlazeAsmBackend {
+  MCELFObjectFormat Format;
+
+public:
+  Triple::OSType OSType;
+  ELFMBlazeAsmBackend(const Target &T, Triple::OSType _OSType)
+    : MBlazeAsmBackend(T), OSType(_OSType) {
+    HasScatteredSymbols = true;
+  }
+
+  virtual const MCObjectFormat &getObjectFormat() const {
+    return Format;
+  }
+
+
+  void ApplyFixup(const MCFixup &Fixup, MCDataFragment &DF,
+                  uint64_t Value) const;
+
+  bool isVirtualSection(const MCSection &Section) const {
+    const MCSectionELF &SE = static_cast<const MCSectionELF&>(Section);
+    return SE.getType() == MCSectionELF::SHT_NOBITS;
+  }
+
+  MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
+    return new ELFObjectWriter(OS, /*Is64Bit=*/false,
+                               OSType,
+                               /*IsLittleEndian=*/false,
+                               /*HasRelocationAddend=*/true);
+  }
+};
+
+void ELFMBlazeAsmBackend::ApplyFixup(const MCFixup &Fixup, MCDataFragment &DF,
+                                     uint64_t Value) const {
+  unsigned Size = getFixupKindSize(Fixup.getKind());
+            
+  assert(Fixup.getOffset() + Size <= DF.getContents().size() &&
+         "Invalid fixup offset!");
+
+  char *data = DF.getContents().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
+
+TargetAsmBackend *llvm::createMBlazeAsmBackend(const Target &T,
+                                            const std::string &TT) {
+  switch (Triple(TT).getOS()) {
+  case Triple::Darwin:
+    assert(0 && "Mac not supported on MBlaze");
+  case Triple::MinGW32:
+  case Triple::Cygwin:
+  case Triple::Win32:
+    assert(0 && "Windows not supported on MBlaze");
+  default:
+    return new ELFMBlazeAsmBackend(T, Triple(TT).getOS());
+  }
+}