1 //===-- SystemZMCAsmBackend.cpp - SystemZ assembler backend ---------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "MCTargetDesc/SystemZMCTargetDesc.h"
11 #include "MCTargetDesc/SystemZMCFixups.h"
12 #include "llvm/MC/MCAsmBackend.h"
13 #include "llvm/MC/MCELFObjectWriter.h"
14 #include "llvm/MC/MCFixupKindInfo.h"
15 #include "llvm/MC/MCInst.h"
16 #include "llvm/MC/MCObjectWriter.h"
20 // Value is a fully-resolved relocation value: Symbol + Addend [- Pivot].
21 // Return the bits that should be installed in a relocation field for
23 static uint64_t extractBitsForFixup(MCFixupKind Kind, uint64_t Value) {
24 if (Kind < FirstTargetFixupKind)
27 switch (unsigned(Kind)) {
28 case SystemZ::FK_390_PC16DBL:
29 case SystemZ::FK_390_PC32DBL:
30 return (int64_t)Value / 2;
32 case SystemZ::FK_390_TLS_CALL:
36 llvm_unreachable("Unknown fixup kind!");
40 class SystemZMCAsmBackend : public MCAsmBackend {
43 SystemZMCAsmBackend(uint8_t osABI)
46 // Override MCAsmBackend
47 unsigned getNumFixupKinds() const override {
48 return SystemZ::NumTargetFixupKinds;
50 const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
51 void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
52 uint64_t Value, bool IsPCRel) const override;
53 bool mayNeedRelaxation(const MCInst &Inst) const override {
56 bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
57 const MCRelaxableFragment *Fragment,
58 const MCAsmLayout &Layout) const override {
61 void relaxInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
62 MCInst &Res) const override {
63 llvm_unreachable("SystemZ does do not have assembler relaxation");
65 bool writeNopData(uint64_t Count, MCObjectWriter *OW) const override;
66 MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
67 return createSystemZObjectWriter(OS, OSABI);
70 } // end anonymous namespace
72 const MCFixupKindInfo &
73 SystemZMCAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
74 const static MCFixupKindInfo Infos[SystemZ::NumTargetFixupKinds] = {
75 { "FK_390_PC16DBL", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
76 { "FK_390_PC32DBL", 0, 32, MCFixupKindInfo::FKF_IsPCRel },
77 { "FK_390_TLS_CALL", 0, 0, 0 }
80 if (Kind < FirstTargetFixupKind)
81 return MCAsmBackend::getFixupKindInfo(Kind);
83 assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
85 return Infos[Kind - FirstTargetFixupKind];
88 void SystemZMCAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
89 unsigned DataSize, uint64_t Value,
91 MCFixupKind Kind = Fixup.getKind();
92 unsigned Offset = Fixup.getOffset();
93 unsigned Size = (getFixupKindInfo(Kind).TargetSize + 7) / 8;
95 assert(Offset + Size <= DataSize && "Invalid fixup offset!");
97 // Big-endian insertion of Size bytes.
98 Value = extractBitsForFixup(Kind, Value);
99 unsigned ShiftValue = (Size * 8) - 8;
100 for (unsigned I = 0; I != Size; ++I) {
101 Data[Offset + I] |= uint8_t(Value >> ShiftValue);
106 bool SystemZMCAsmBackend::writeNopData(uint64_t Count,
107 MCObjectWriter *OW) const {
108 for (uint64_t I = 0; I != Count; ++I)
113 MCAsmBackend *llvm::createSystemZMCAsmBackend(const Target &T,
114 const MCRegisterInfo &MRI,
115 const Triple &TT, StringRef CPU) {
116 uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TT.getOS());
117 return new SystemZMCAsmBackend(OSABI);