1 files changed, 189 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp b/contrib/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp
new file mode 100644
index 0000000..60e8c8f
--- /dev/null
+++ b/contrib/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp
@@ -0,0 +1,189 @@
+//===-- AMDGPUAsmBackend.cpp - AMDGPU Assembler Backend -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+/// \file
+//===----------------------------------------------------------------------===//
+
+#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
+#include "MCTargetDesc/AMDGPUFixupKinds.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCFixupKindInfo.h"
+#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCValue.h"
+#include "llvm/Support/TargetRegistry.h"
+
+using namespace llvm;
+
+namespace {
+
+class AMDGPUMCObjectWriter : public MCObjectWriter {
+public:
+  AMDGPUMCObjectWriter(raw_pwrite_stream &OS) : MCObjectWriter(OS, true) {}
+  void executePostLayoutBinding(MCAssembler &Asm,
+                                const MCAsmLayout &Layout) override {
+    //XXX: Implement if necessary.
+  }
+  void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
+                        const MCFragment *Fragment, const MCFixup &Fixup,
+                        MCValue Target, bool &IsPCRel,
+                        uint64_t &FixedValue) override {
+    assert(!"Not implemented");
+  }
+
+  void writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
+
+};
+
+class AMDGPUAsmBackend : public MCAsmBackend {
+public:
+  AMDGPUAsmBackend(const Target &T)
+    : MCAsmBackend() {}
+
+  unsigned getNumFixupKinds() const override { return AMDGPU::NumTargetFixupKinds; };
+  void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
+                  uint64_t Value, bool IsPCRel) const override;
+  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
+                            const MCRelaxableFragment *DF,
+                            const MCAsmLayout &Layout) const override {
+    return false;
+  }
+  void relaxInstruction(const MCInst &Inst, MCInst &Res) const override {
+    assert(!"Not implemented");
+  }
+  bool mayNeedRelaxation(const MCInst &Inst) const override { return false; }
+  bool writeNopData(uint64_t Count, MCObjectWriter *OW) const override;
+
+  const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
+};
+
+} //End anonymous namespace
+
+void AMDGPUMCObjectWriter::writeObject(MCAssembler &Asm,
+                                       const MCAsmLayout &Layout) {
+  for (MCAssembler::iterator I = Asm.begin(), E = Asm.end(); I != E; ++I) {
+    Asm.writeSectionData(&*I, Layout);
+  }
+}
+
+static unsigned getFixupKindNumBytes(unsigned Kind) {
+  switch (Kind) {
+  case FK_Data_1:
+    return 1;
+  case FK_Data_2:
+    return 2;
+  case FK_Data_4:
+    return 4;
+  case FK_Data_8:
+    return 8;
+  default:
+    llvm_unreachable("Unknown fixup kind!");
+  }
+}
+
+void AMDGPUAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
+                                  unsigned DataSize, uint64_t Value,
+                                  bool IsPCRel) const {
+
+  switch ((unsigned)Fixup.getKind()) {
+    case AMDGPU::fixup_si_sopp_br: {
+      uint16_t *Dst = (uint16_t*)(Data + Fixup.getOffset());
+      *Dst = (Value - 4) / 4;
+      break;
+    }
+
+    case AMDGPU::fixup_si_rodata: {
+      uint32_t *Dst = (uint32_t*)(Data + Fixup.getOffset());
+      // We emit constant data at the end of the text section and generate its
+      // address using the following code sequence:
+      // s_getpc_b64 s[0:1]
+      // s_add_u32 s0, s0, $symbol
+      // s_addc_u32 s1, s1, 0
+      //
+      // s_getpc_b64 returns the address of the s_add_u32 instruction and then
+      // the fixup replaces $symbol with a literal constant, which is a
+      // pc-relative  offset from the encoding of the $symbol operand to the
+      // constant data.
+      //
+      // What we want here is an offset from the start of the s_add_u32
+      // instruction to the constant data, but since the encoding of $symbol
+      // starts 4 bytes after the start of the add instruction, we end up
+      // with an offset that is 4 bytes too small.  This requires us to
+      // add 4 to the fixup value before applying it.
+      *Dst = Value + 4;
+      break;
+    }
+    default: {
+      // FIXME: Copied from AArch64
+      unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind());
+      if (!Value)
+        return; // Doesn't change encoding.
+      MCFixupKindInfo Info = getFixupKindInfo(Fixup.getKind());
+
+      // Shift the value into position.
+      Value <<= Info.TargetOffset;
+
+      unsigned Offset = Fixup.getOffset();
+      assert(Offset + NumBytes <= DataSize && "Invalid fixup offset!");
+
+      // For each byte of the fragment that the fixup touches, mask in the
+      // bits from the fixup value.
+      for (unsigned i = 0; i != NumBytes; ++i)
+        Data[Offset + i] |= uint8_t((Value >> (i * 8)) & 0xff);
+    }
+  }
+}
+
+const MCFixupKindInfo &AMDGPUAsmBackend::getFixupKindInfo(
+                                                       MCFixupKind Kind) const {
+  const static MCFixupKindInfo Infos[AMDGPU::NumTargetFixupKinds] = {
+    // name                   offset bits  flags
+    { "fixup_si_sopp_br",     0,     16,   MCFixupKindInfo::FKF_IsPCRel },
+    { "fixup_si_rodata",      0,     32,   MCFixupKindInfo::FKF_IsPCRel }
+  };
+
+  if (Kind < FirstTargetFixupKind)
+    return MCAsmBackend::getFixupKindInfo(Kind);
+
+  return Infos[Kind - FirstTargetFixupKind];
+}
+
+bool AMDGPUAsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const {
+  OW->WriteZeros(Count);
+
+  return true;
+}
+
+//===----------------------------------------------------------------------===//
+// ELFAMDGPUAsmBackend class
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+class ELFAMDGPUAsmBackend : public AMDGPUAsmBackend {
+  bool Is64Bit;
+
+public:
+  ELFAMDGPUAsmBackend(const Target &T, bool Is64Bit) :
+      AMDGPUAsmBackend(T), Is64Bit(Is64Bit) { }
+
+  MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
+    return createAMDGPUELFObjectWriter(Is64Bit, OS);
+  }
+};
+
+} // end anonymous namespace
+
+MCAsmBackend *llvm::createAMDGPUAsmBackend(const Target &T,
+                                           const MCRegisterInfo &MRI,
+                                           const Triple &TT, StringRef CPU) {
+  Triple TargetTriple(TT);
+
+  // Use 64-bit ELF for amdgcn
+  return new ELFAMDGPUAsmBackend(T, TargetTriple.getArch() == Triple::amdgcn);
+}