Imported Upstream version 5.18.0.246

Former-commit-id: 0c7ce5b1a7851e13f22acfd379b7f9fb304e4833

external/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp

@@ -0,0 +1,132 @@
+//===-- SystemZMCAsmBackend.cpp - SystemZ 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/SystemZMCFixups.h"
+#include "MCTargetDesc/SystemZMCTargetDesc.h"
+#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCELFObjectWriter.h"
+#include "llvm/MC/MCFixupKindInfo.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+
+using namespace llvm;
+
+// Value is a fully-resolved relocation value: Symbol + Addend [- Pivot].
+// Return the bits that should be installed in a relocation field for
+// fixup kind Kind.
+static uint64_t extractBitsForFixup(MCFixupKind Kind, uint64_t Value) {
+  if (Kind < FirstTargetFixupKind)
+    return Value;
+
+  switch (unsigned(Kind)) {
+  case SystemZ::FK_390_PC12DBL:
+  case SystemZ::FK_390_PC16DBL:
+  case SystemZ::FK_390_PC24DBL:
+  case SystemZ::FK_390_PC32DBL:
+    return (int64_t)Value / 2;
+
+  case SystemZ::FK_390_TLS_CALL:
+    return 0;
+  }
+
+  llvm_unreachable("Unknown fixup kind!");
+}
+
+namespace {
+class SystemZMCAsmBackend : public MCAsmBackend {
+  uint8_t OSABI;
+public:
+  SystemZMCAsmBackend(uint8_t osABI)
+    : OSABI(osABI) {}
+
+  // Override MCAsmBackend
+  unsigned getNumFixupKinds() const override {
+    return SystemZ::NumTargetFixupKinds;
+  }
+  const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
+  void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
+                  const MCValue &Target, MutableArrayRef<char> Data,
+                  uint64_t Value, bool IsResolved) const override;
+  bool mayNeedRelaxation(const MCInst &Inst) const override {
+    return false;
+  }
+  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
+                            const MCRelaxableFragment *Fragment,
+                            const MCAsmLayout &Layout) const override {
+    return false;
+  }
+  void relaxInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
+                        MCInst &Res) const override {
+    llvm_unreachable("SystemZ does do not have assembler relaxation");
+  }
+  bool writeNopData(uint64_t Count, MCObjectWriter *OW) const override;
+  std::unique_ptr<MCObjectWriter>
+  createObjectWriter(raw_pwrite_stream &OS) const override {
+    return createSystemZObjectWriter(OS, OSABI);
+  }
+};
+} // end anonymous namespace
+
+const MCFixupKindInfo &
+SystemZMCAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
+  const static MCFixupKindInfo Infos[SystemZ::NumTargetFixupKinds] = {
+    { "FK_390_PC12DBL",  4, 12, MCFixupKindInfo::FKF_IsPCRel },
+    { "FK_390_PC16DBL",  0, 16, MCFixupKindInfo::FKF_IsPCRel },
+    { "FK_390_PC24DBL",  0, 24, MCFixupKindInfo::FKF_IsPCRel },
+    { "FK_390_PC32DBL",  0, 32, MCFixupKindInfo::FKF_IsPCRel },
+    { "FK_390_TLS_CALL", 0, 0, 0 }
+  };
+
+  if (Kind < FirstTargetFixupKind)
+    return MCAsmBackend::getFixupKindInfo(Kind);
+
+  assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
+         "Invalid kind!");
+  return Infos[Kind - FirstTargetFixupKind];
+}
+
+void SystemZMCAsmBackend::applyFixup(const MCAssembler &Asm,
+                                     const MCFixup &Fixup,
+                                     const MCValue &Target,
+                                     MutableArrayRef<char> Data, uint64_t Value,
+                                     bool IsResolved) const {
+  MCFixupKind Kind = Fixup.getKind();
+  unsigned Offset = Fixup.getOffset();
+  unsigned BitSize = getFixupKindInfo(Kind).TargetSize;
+  unsigned Size = (BitSize + 7) / 8;
+
+  assert(Offset + Size <= Data.size() && "Invalid fixup offset!");
+
+  // Big-endian insertion of Size bytes.
+  Value = extractBitsForFixup(Kind, Value);
+  if (BitSize < 64)
+    Value &= ((uint64_t)1 << BitSize) - 1;
+  unsigned ShiftValue = (Size * 8) - 8;
+  for (unsigned I = 0; I != Size; ++I) {
+    Data[Offset + I] |= uint8_t(Value >> ShiftValue);
+    ShiftValue -= 8;
+  }
+}
+
+bool SystemZMCAsmBackend::writeNopData(uint64_t Count,
+                                       MCObjectWriter *OW) const {
+  for (uint64_t I = 0; I != Count; ++I)
+    OW->write8(7);
+  return true;
+}
+
+MCAsmBackend *llvm::createSystemZMCAsmBackend(const Target &T,
+                                              const MCSubtargetInfo &STI,
+                                              const MCRegisterInfo &MRI,
+                                              const MCTargetOptions &Options) {
+  uint8_t OSABI =
+      MCELFObjectTargetWriter::getOSABI(STI.getTargetTriple().getOS());
+  return new SystemZMCAsmBackend(OSABI);
+}