xref: /freebsd-src/contrib/llvm-project/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
181ad6265SDimitry Andric //===-- LoongArchAsmBackend.cpp - LoongArch Assembler Backend -*- C++ -*---===//
281ad6265SDimitry Andric //
381ad6265SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
481ad6265SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
581ad6265SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
681ad6265SDimitry Andric //
781ad6265SDimitry Andric //===----------------------------------------------------------------------===//
881ad6265SDimitry Andric //
981ad6265SDimitry Andric // This file implements the LoongArchAsmBackend class.
1081ad6265SDimitry Andric //
1181ad6265SDimitry Andric //===----------------------------------------------------------------------===//
1281ad6265SDimitry Andric 
1381ad6265SDimitry Andric #include "LoongArchAsmBackend.h"
14bdd1243dSDimitry Andric #include "LoongArchFixupKinds.h"
157a6dacacSDimitry Andric #include "llvm/MC/MCAsmInfo.h"
1681ad6265SDimitry Andric #include "llvm/MC/MCAssembler.h"
1781ad6265SDimitry Andric #include "llvm/MC/MCContext.h"
1881ad6265SDimitry Andric #include "llvm/MC/MCELFObjectWriter.h"
197a6dacacSDimitry Andric #include "llvm/MC/MCExpr.h"
207a6dacacSDimitry Andric #include "llvm/MC/MCSection.h"
21bdd1243dSDimitry Andric #include "llvm/MC/MCValue.h"
2281ad6265SDimitry Andric #include "llvm/Support/EndianStream.h"
237a6dacacSDimitry Andric #include "llvm/Support/LEB128.h"
247a6dacacSDimitry Andric #include "llvm/Support/MathExtras.h"
2581ad6265SDimitry Andric 
2681ad6265SDimitry Andric #define DEBUG_TYPE "loongarch-asmbackend"
2781ad6265SDimitry Andric 
2881ad6265SDimitry Andric using namespace llvm;
2981ad6265SDimitry Andric 
30bdd1243dSDimitry Andric std::optional<MCFixupKind>
31bdd1243dSDimitry Andric LoongArchAsmBackend::getFixupKind(StringRef Name) const {
32bdd1243dSDimitry Andric   if (STI.getTargetTriple().isOSBinFormatELF()) {
33bdd1243dSDimitry Andric     auto Type = llvm::StringSwitch<unsigned>(Name)
34bdd1243dSDimitry Andric #define ELF_RELOC(X, Y) .Case(#X, Y)
35bdd1243dSDimitry Andric #include "llvm/BinaryFormat/ELFRelocs/LoongArch.def"
36bdd1243dSDimitry Andric #undef ELF_RELOC
37bdd1243dSDimitry Andric                     .Case("BFD_RELOC_NONE", ELF::R_LARCH_NONE)
38bdd1243dSDimitry Andric                     .Case("BFD_RELOC_32", ELF::R_LARCH_32)
39bdd1243dSDimitry Andric                     .Case("BFD_RELOC_64", ELF::R_LARCH_64)
40bdd1243dSDimitry Andric                     .Default(-1u);
41bdd1243dSDimitry Andric     if (Type != -1u)
42bdd1243dSDimitry Andric       return static_cast<MCFixupKind>(FirstLiteralRelocationKind + Type);
43bdd1243dSDimitry Andric   }
44bdd1243dSDimitry Andric   return std::nullopt;
45bdd1243dSDimitry Andric }
46bdd1243dSDimitry Andric 
47bdd1243dSDimitry Andric const MCFixupKindInfo &
48bdd1243dSDimitry Andric LoongArchAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
49bdd1243dSDimitry Andric   const static MCFixupKindInfo Infos[] = {
50bdd1243dSDimitry Andric       // This table *must* be in the order that the fixup_* kinds are defined in
51bdd1243dSDimitry Andric       // LoongArchFixupKinds.h.
52bdd1243dSDimitry Andric       //
53bdd1243dSDimitry Andric       // {name, offset, bits, flags}
54bdd1243dSDimitry Andric       {"fixup_loongarch_b16", 10, 16, MCFixupKindInfo::FKF_IsPCRel},
55bdd1243dSDimitry Andric       {"fixup_loongarch_b21", 0, 26, MCFixupKindInfo::FKF_IsPCRel},
56bdd1243dSDimitry Andric       {"fixup_loongarch_b26", 0, 26, MCFixupKindInfo::FKF_IsPCRel},
57bdd1243dSDimitry Andric       {"fixup_loongarch_abs_hi20", 5, 20, 0},
58bdd1243dSDimitry Andric       {"fixup_loongarch_abs_lo12", 10, 12, 0},
59bdd1243dSDimitry Andric       {"fixup_loongarch_abs64_lo20", 5, 20, 0},
60bdd1243dSDimitry Andric       {"fixup_loongarch_abs64_hi12", 10, 12, 0},
61bdd1243dSDimitry Andric       {"fixup_loongarch_tls_le_hi20", 5, 20, 0},
62bdd1243dSDimitry Andric       {"fixup_loongarch_tls_le_lo12", 10, 12, 0},
63bdd1243dSDimitry Andric       {"fixup_loongarch_tls_le64_lo20", 5, 20, 0},
64bdd1243dSDimitry Andric       {"fixup_loongarch_tls_le64_hi12", 10, 12, 0},
65bdd1243dSDimitry Andric       // TODO: Add more fixup kinds.
66bdd1243dSDimitry Andric   };
67bdd1243dSDimitry Andric 
68bdd1243dSDimitry Andric   static_assert((std::size(Infos)) == LoongArch::NumTargetFixupKinds,
69bdd1243dSDimitry Andric                 "Not all fixup kinds added to Infos array");
70bdd1243dSDimitry Andric 
71bdd1243dSDimitry Andric   // Fixup kinds from .reloc directive are like R_LARCH_NONE. They
72bdd1243dSDimitry Andric   // do not require any extra processing.
73bdd1243dSDimitry Andric   if (Kind >= FirstLiteralRelocationKind)
74bdd1243dSDimitry Andric     return MCAsmBackend::getFixupKindInfo(FK_NONE);
75bdd1243dSDimitry Andric 
76bdd1243dSDimitry Andric   if (Kind < FirstTargetFixupKind)
77bdd1243dSDimitry Andric     return MCAsmBackend::getFixupKindInfo(Kind);
78bdd1243dSDimitry Andric 
79bdd1243dSDimitry Andric   assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
80bdd1243dSDimitry Andric          "Invalid kind!");
81bdd1243dSDimitry Andric   return Infos[Kind - FirstTargetFixupKind];
82bdd1243dSDimitry Andric }
83bdd1243dSDimitry Andric 
84bdd1243dSDimitry Andric static void reportOutOfRangeError(MCContext &Ctx, SMLoc Loc, unsigned N) {
85bdd1243dSDimitry Andric   Ctx.reportError(Loc, "fixup value out of range [" + Twine(llvm::minIntN(N)) +
86bdd1243dSDimitry Andric                            ", " + Twine(llvm::maxIntN(N)) + "]");
87bdd1243dSDimitry Andric }
88bdd1243dSDimitry Andric 
89bdd1243dSDimitry Andric static uint64_t adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
90bdd1243dSDimitry Andric                                  MCContext &Ctx) {
91bdd1243dSDimitry Andric   switch (Fixup.getTargetKind()) {
92bdd1243dSDimitry Andric   default:
93bdd1243dSDimitry Andric     llvm_unreachable("Unknown fixup kind");
94bdd1243dSDimitry Andric   case FK_Data_1:
95bdd1243dSDimitry Andric   case FK_Data_2:
96bdd1243dSDimitry Andric   case FK_Data_4:
97bdd1243dSDimitry Andric   case FK_Data_8:
981db9f3b2SDimitry Andric   case FK_Data_leb128:
99bdd1243dSDimitry Andric     return Value;
100bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_b16: {
101bdd1243dSDimitry Andric     if (!isInt<18>(Value))
102bdd1243dSDimitry Andric       reportOutOfRangeError(Ctx, Fixup.getLoc(), 18);
103bdd1243dSDimitry Andric     if (Value % 4)
104bdd1243dSDimitry Andric       Ctx.reportError(Fixup.getLoc(), "fixup value must be 4-byte aligned");
105bdd1243dSDimitry Andric     return (Value >> 2) & 0xffff;
106bdd1243dSDimitry Andric   }
107bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_b21: {
108bdd1243dSDimitry Andric     if (!isInt<23>(Value))
109bdd1243dSDimitry Andric       reportOutOfRangeError(Ctx, Fixup.getLoc(), 23);
110bdd1243dSDimitry Andric     if (Value % 4)
111bdd1243dSDimitry Andric       Ctx.reportError(Fixup.getLoc(), "fixup value must be 4-byte aligned");
112bdd1243dSDimitry Andric     return ((Value & 0x3fffc) << 8) | ((Value >> 18) & 0x1f);
113bdd1243dSDimitry Andric   }
114bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_b26: {
115bdd1243dSDimitry Andric     if (!isInt<28>(Value))
116bdd1243dSDimitry Andric       reportOutOfRangeError(Ctx, Fixup.getLoc(), 28);
117bdd1243dSDimitry Andric     if (Value % 4)
118bdd1243dSDimitry Andric       Ctx.reportError(Fixup.getLoc(), "fixup value must be 4-byte aligned");
119bdd1243dSDimitry Andric     return ((Value & 0x3fffc) << 8) | ((Value >> 18) & 0x3ff);
120bdd1243dSDimitry Andric   }
121bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_abs_hi20:
122bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_tls_le_hi20:
123bdd1243dSDimitry Andric     return (Value >> 12) & 0xfffff;
124bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_abs_lo12:
125bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_tls_le_lo12:
126bdd1243dSDimitry Andric     return Value & 0xfff;
127bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_abs64_lo20:
128bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_tls_le64_lo20:
129bdd1243dSDimitry Andric     return (Value >> 32) & 0xfffff;
130bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_abs64_hi12:
131bdd1243dSDimitry Andric   case LoongArch::fixup_loongarch_tls_le64_hi12:
132bdd1243dSDimitry Andric     return (Value >> 52) & 0xfff;
133bdd1243dSDimitry Andric   }
134bdd1243dSDimitry Andric }
135bdd1243dSDimitry Andric 
1361db9f3b2SDimitry Andric static void fixupLeb128(MCContext &Ctx, const MCFixup &Fixup,
1371db9f3b2SDimitry Andric                         MutableArrayRef<char> Data, uint64_t Value) {
1381db9f3b2SDimitry Andric   unsigned I;
1391db9f3b2SDimitry Andric   for (I = 0; I != Data.size() && Value; ++I, Value >>= 7)
1401db9f3b2SDimitry Andric     Data[I] |= uint8_t(Value & 0x7f);
1411db9f3b2SDimitry Andric   if (Value)
1421db9f3b2SDimitry Andric     Ctx.reportError(Fixup.getLoc(), "Invalid uleb128 value!");
1431db9f3b2SDimitry Andric }
1441db9f3b2SDimitry Andric 
14581ad6265SDimitry Andric void LoongArchAsmBackend::applyFixup(const MCAssembler &Asm,
14681ad6265SDimitry Andric                                      const MCFixup &Fixup,
14781ad6265SDimitry Andric                                      const MCValue &Target,
14881ad6265SDimitry Andric                                      MutableArrayRef<char> Data, uint64_t Value,
14981ad6265SDimitry Andric                                      bool IsResolved,
15081ad6265SDimitry Andric                                      const MCSubtargetInfo *STI) const {
151bdd1243dSDimitry Andric   if (!Value)
152bdd1243dSDimitry Andric     return; // Doesn't change encoding.
153bdd1243dSDimitry Andric 
154bdd1243dSDimitry Andric   MCFixupKind Kind = Fixup.getKind();
155bdd1243dSDimitry Andric   if (Kind >= FirstLiteralRelocationKind)
15681ad6265SDimitry Andric     return;
157bdd1243dSDimitry Andric   MCFixupKindInfo Info = getFixupKindInfo(Kind);
158bdd1243dSDimitry Andric   MCContext &Ctx = Asm.getContext();
159bdd1243dSDimitry Andric 
1601db9f3b2SDimitry Andric   // Fixup leb128 separately.
1611db9f3b2SDimitry Andric   if (Fixup.getTargetKind() == FK_Data_leb128)
1621db9f3b2SDimitry Andric     return fixupLeb128(Ctx, Fixup, Data, Value);
1631db9f3b2SDimitry Andric 
164bdd1243dSDimitry Andric   // Apply any target-specific value adjustments.
165bdd1243dSDimitry Andric   Value = adjustFixupValue(Fixup, Value, Ctx);
166bdd1243dSDimitry Andric 
167bdd1243dSDimitry Andric   // Shift the value into position.
168bdd1243dSDimitry Andric   Value <<= Info.TargetOffset;
169bdd1243dSDimitry Andric 
170bdd1243dSDimitry Andric   unsigned Offset = Fixup.getOffset();
171bdd1243dSDimitry Andric   unsigned NumBytes = alignTo(Info.TargetSize + Info.TargetOffset, 8) / 8;
172bdd1243dSDimitry Andric 
173bdd1243dSDimitry Andric   assert(Offset + NumBytes <= Data.size() && "Invalid fixup offset!");
174bdd1243dSDimitry Andric   // For each byte of the fragment that the fixup touches, mask in the
175bdd1243dSDimitry Andric   // bits from the fixup value.
176bdd1243dSDimitry Andric   for (unsigned I = 0; I != NumBytes; ++I) {
177bdd1243dSDimitry Andric     Data[Offset + I] |= uint8_t((Value >> (I * 8)) & 0xff);
178bdd1243dSDimitry Andric   }
17981ad6265SDimitry Andric }
18081ad6265SDimitry Andric 
1817a6dacacSDimitry Andric // Linker relaxation may change code size. We have to insert Nops
1827a6dacacSDimitry Andric // for .align directive when linker relaxation enabled. So then Linker
1837a6dacacSDimitry Andric // could satisfy alignment by removing Nops.
1847a6dacacSDimitry Andric // The function returns the total Nops Size we need to insert.
1857a6dacacSDimitry Andric bool LoongArchAsmBackend::shouldInsertExtraNopBytesForCodeAlign(
1867a6dacacSDimitry Andric     const MCAlignFragment &AF, unsigned &Size) {
1877a6dacacSDimitry Andric   // Calculate Nops Size only when linker relaxation enabled.
1887a6dacacSDimitry Andric   if (!AF.getSubtargetInfo()->hasFeature(LoongArch::FeatureRelax))
1897a6dacacSDimitry Andric     return false;
1907a6dacacSDimitry Andric 
1917a6dacacSDimitry Andric   // Ignore alignment if MaxBytesToEmit is less than the minimum Nop size.
1927a6dacacSDimitry Andric   const unsigned MinNopLen = 4;
1937a6dacacSDimitry Andric   if (AF.getMaxBytesToEmit() < MinNopLen)
1947a6dacacSDimitry Andric     return false;
1957a6dacacSDimitry Andric   Size = AF.getAlignment().value() - MinNopLen;
1967a6dacacSDimitry Andric   return AF.getAlignment() > MinNopLen;
1977a6dacacSDimitry Andric }
1987a6dacacSDimitry Andric 
1997a6dacacSDimitry Andric // We need to insert R_LARCH_ALIGN relocation type to indicate the
2007a6dacacSDimitry Andric // position of Nops and the total bytes of the Nops have been inserted
2017a6dacacSDimitry Andric // when linker relaxation enabled.
2027a6dacacSDimitry Andric // The function inserts fixup_loongarch_align fixup which eventually will
2037a6dacacSDimitry Andric // transfer to R_LARCH_ALIGN relocation type.
2047a6dacacSDimitry Andric // The improved R_LARCH_ALIGN requires symbol index. The lowest 8 bits of
2057a6dacacSDimitry Andric // addend represent alignment and the other bits of addend represent the
2067a6dacacSDimitry Andric // maximum number of bytes to emit. The maximum number of bytes is zero
2077a6dacacSDimitry Andric // means ignore the emit limit.
208*0fca6ea1SDimitry Andric bool LoongArchAsmBackend::shouldInsertFixupForCodeAlign(MCAssembler &Asm,
209*0fca6ea1SDimitry Andric                                                         MCAlignFragment &AF) {
2107a6dacacSDimitry Andric   // Insert the fixup only when linker relaxation enabled.
2117a6dacacSDimitry Andric   if (!AF.getSubtargetInfo()->hasFeature(LoongArch::FeatureRelax))
2127a6dacacSDimitry Andric     return false;
2137a6dacacSDimitry Andric 
2147a6dacacSDimitry Andric   // Calculate total Nops we need to insert. If there are none to insert
2157a6dacacSDimitry Andric   // then simply return.
216*0fca6ea1SDimitry Andric   unsigned InsertedNopBytes;
217*0fca6ea1SDimitry Andric   if (!shouldInsertExtraNopBytesForCodeAlign(AF, InsertedNopBytes))
2187a6dacacSDimitry Andric     return false;
2197a6dacacSDimitry Andric 
2207a6dacacSDimitry Andric   MCSection *Sec = AF.getParent();
2217a6dacacSDimitry Andric   MCContext &Ctx = Asm.getContext();
2227a6dacacSDimitry Andric   const MCExpr *Dummy = MCConstantExpr::create(0, Ctx);
2237a6dacacSDimitry Andric   // Create fixup_loongarch_align fixup.
2247a6dacacSDimitry Andric   MCFixup Fixup =
2257a6dacacSDimitry Andric       MCFixup::create(0, Dummy, MCFixupKind(LoongArch::fixup_loongarch_align));
226*0fca6ea1SDimitry Andric   unsigned MaxBytesToEmit = AF.getMaxBytesToEmit();
227*0fca6ea1SDimitry Andric 
228*0fca6ea1SDimitry Andric   auto createExtendedValue = [&]() {
2297a6dacacSDimitry Andric     const MCSymbolRefExpr *MCSym = getSecToAlignSym()[Sec];
2307a6dacacSDimitry Andric     if (MCSym == nullptr) {
231*0fca6ea1SDimitry Andric       // Define a marker symbol at the section with an offset of 0.
2327a6dacacSDimitry Andric       MCSymbol *Sym = Ctx.createNamedTempSymbol("la-relax-align");
2337a6dacacSDimitry Andric       Sym->setFragment(&*Sec->getBeginSymbol()->getFragment());
2347a6dacacSDimitry Andric       Asm.registerSymbol(*Sym);
2357a6dacacSDimitry Andric       MCSym = MCSymbolRefExpr::create(Sym, Ctx);
2367a6dacacSDimitry Andric       getSecToAlignSym()[Sec] = MCSym;
2377a6dacacSDimitry Andric     }
238*0fca6ea1SDimitry Andric     return MCValue::get(MCSym, nullptr,
239*0fca6ea1SDimitry Andric                         MaxBytesToEmit << 8 | Log2(AF.getAlignment()));
240*0fca6ea1SDimitry Andric   };
2417a6dacacSDimitry Andric 
2427a6dacacSDimitry Andric   uint64_t FixedValue = 0;
243*0fca6ea1SDimitry Andric   MCValue Value = MaxBytesToEmit >= InsertedNopBytes
244*0fca6ea1SDimitry Andric                       ? MCValue::get(InsertedNopBytes)
245*0fca6ea1SDimitry Andric                       : createExtendedValue();
246*0fca6ea1SDimitry Andric   Asm.getWriter().recordRelocation(Asm, &AF, Fixup, Value, FixedValue);
2477a6dacacSDimitry Andric 
2487a6dacacSDimitry Andric   return true;
2497a6dacacSDimitry Andric }
2507a6dacacSDimitry Andric 
25181ad6265SDimitry Andric bool LoongArchAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
25281ad6265SDimitry Andric                                                 const MCFixup &Fixup,
2535f757f3fSDimitry Andric                                                 const MCValue &Target,
2545f757f3fSDimitry Andric                                                 const MCSubtargetInfo *STI) {
255bdd1243dSDimitry Andric   if (Fixup.getKind() >= FirstLiteralRelocationKind)
256bdd1243dSDimitry Andric     return true;
257bdd1243dSDimitry Andric   switch (Fixup.getTargetKind()) {
258bdd1243dSDimitry Andric   default:
2595f757f3fSDimitry Andric     return STI->hasFeature(LoongArch::FeatureRelax);
260bdd1243dSDimitry Andric   case FK_Data_1:
261bdd1243dSDimitry Andric   case FK_Data_2:
262bdd1243dSDimitry Andric   case FK_Data_4:
263bdd1243dSDimitry Andric   case FK_Data_8:
2641db9f3b2SDimitry Andric   case FK_Data_leb128:
265bdd1243dSDimitry Andric     return !Target.isAbsolute();
266bdd1243dSDimitry Andric   }
26781ad6265SDimitry Andric }
26881ad6265SDimitry Andric 
269cb14a3feSDimitry Andric static inline std::pair<MCFixupKind, MCFixupKind>
270cb14a3feSDimitry Andric getRelocPairForSize(unsigned Size) {
271cb14a3feSDimitry Andric   switch (Size) {
272cb14a3feSDimitry Andric   default:
273cb14a3feSDimitry Andric     llvm_unreachable("unsupported fixup size");
274cb14a3feSDimitry Andric   case 6:
275cb14a3feSDimitry Andric     return std::make_pair(
276cb14a3feSDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD6),
277cb14a3feSDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB6));
278cb14a3feSDimitry Andric   case 8:
279cb14a3feSDimitry Andric     return std::make_pair(
280cb14a3feSDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD8),
281cb14a3feSDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB8));
282cb14a3feSDimitry Andric   case 16:
283cb14a3feSDimitry Andric     return std::make_pair(
284cb14a3feSDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD16),
285cb14a3feSDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB16));
286cb14a3feSDimitry Andric   case 32:
287cb14a3feSDimitry Andric     return std::make_pair(
288cb14a3feSDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD32),
289cb14a3feSDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB32));
290cb14a3feSDimitry Andric   case 64:
291cb14a3feSDimitry Andric     return std::make_pair(
292cb14a3feSDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD64),
293cb14a3feSDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB64));
2941db9f3b2SDimitry Andric   case 128:
2951db9f3b2SDimitry Andric     return std::make_pair(
2961db9f3b2SDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD_ULEB128),
2971db9f3b2SDimitry Andric         MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB_ULEB128));
298cb14a3feSDimitry Andric   }
299cb14a3feSDimitry Andric }
300cb14a3feSDimitry Andric 
301*0fca6ea1SDimitry Andric std::pair<bool, bool> LoongArchAsmBackend::relaxLEB128(const MCAssembler &Asm,
302*0fca6ea1SDimitry Andric                                                        MCLEBFragment &LF,
3031db9f3b2SDimitry Andric                                                        int64_t &Value) const {
3041db9f3b2SDimitry Andric   const MCExpr &Expr = LF.getValue();
305*0fca6ea1SDimitry Andric   if (LF.isSigned() || !Expr.evaluateKnownAbsolute(Value, Asm))
3061db9f3b2SDimitry Andric     return std::make_pair(false, false);
3071db9f3b2SDimitry Andric   LF.getFixups().push_back(
3081db9f3b2SDimitry Andric       MCFixup::create(0, &Expr, FK_Data_leb128, Expr.getLoc()));
3091db9f3b2SDimitry Andric   return std::make_pair(true, true);
3101db9f3b2SDimitry Andric }
3111db9f3b2SDimitry Andric 
312*0fca6ea1SDimitry Andric bool LoongArchAsmBackend::relaxDwarfLineAddr(const MCAssembler &Asm,
313*0fca6ea1SDimitry Andric                                              MCDwarfLineAddrFragment &DF,
3147a6dacacSDimitry Andric                                              bool &WasRelaxed) const {
315*0fca6ea1SDimitry Andric   MCContext &C = Asm.getContext();
3167a6dacacSDimitry Andric 
3177a6dacacSDimitry Andric   int64_t LineDelta = DF.getLineDelta();
3187a6dacacSDimitry Andric   const MCExpr &AddrDelta = DF.getAddrDelta();
3197a6dacacSDimitry Andric   SmallVectorImpl<char> &Data = DF.getContents();
3207a6dacacSDimitry Andric   SmallVectorImpl<MCFixup> &Fixups = DF.getFixups();
3217a6dacacSDimitry Andric   size_t OldSize = Data.size();
3227a6dacacSDimitry Andric 
3237a6dacacSDimitry Andric   int64_t Value;
324*0fca6ea1SDimitry Andric   if (AddrDelta.evaluateAsAbsolute(Value, Asm))
3257a6dacacSDimitry Andric     return false;
326*0fca6ea1SDimitry Andric   bool IsAbsolute = AddrDelta.evaluateKnownAbsolute(Value, Asm);
3277a6dacacSDimitry Andric   assert(IsAbsolute && "CFA with invalid expression");
3287a6dacacSDimitry Andric   (void)IsAbsolute;
3297a6dacacSDimitry Andric 
3307a6dacacSDimitry Andric   Data.clear();
3317a6dacacSDimitry Andric   Fixups.clear();
3327a6dacacSDimitry Andric   raw_svector_ostream OS(Data);
3337a6dacacSDimitry Andric 
3347a6dacacSDimitry Andric   // INT64_MAX is a signal that this is actually a DW_LNE_end_sequence.
3357a6dacacSDimitry Andric   if (LineDelta != INT64_MAX) {
3367a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_LNS_advance_line);
3377a6dacacSDimitry Andric     encodeSLEB128(LineDelta, OS);
3387a6dacacSDimitry Andric   }
3397a6dacacSDimitry Andric 
3407a6dacacSDimitry Andric   unsigned Offset;
3417a6dacacSDimitry Andric   std::pair<MCFixupKind, MCFixupKind> FK;
3427a6dacacSDimitry Andric 
3437a6dacacSDimitry Andric   // According to the DWARF specification, the `DW_LNS_fixed_advance_pc` opcode
3447a6dacacSDimitry Andric   // takes a single unsigned half (unencoded) operand. The maximum encodable
3457a6dacacSDimitry Andric   // value is therefore 65535.  Set a conservative upper bound for relaxation.
3467a6dacacSDimitry Andric   if (Value > 60000) {
3477a6dacacSDimitry Andric     unsigned PtrSize = C.getAsmInfo()->getCodePointerSize();
3487a6dacacSDimitry Andric 
3497a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_LNS_extended_op);
3507a6dacacSDimitry Andric     encodeULEB128(PtrSize + 1, OS);
3517a6dacacSDimitry Andric 
3527a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_LNE_set_address);
3537a6dacacSDimitry Andric     Offset = OS.tell();
3547a6dacacSDimitry Andric     assert((PtrSize == 4 || PtrSize == 8) && "Unexpected pointer size");
3557a6dacacSDimitry Andric     FK = getRelocPairForSize(PtrSize == 4 ? 32 : 64);
3567a6dacacSDimitry Andric     OS.write_zeros(PtrSize);
3577a6dacacSDimitry Andric   } else {
3587a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_LNS_fixed_advance_pc);
3597a6dacacSDimitry Andric     Offset = OS.tell();
3607a6dacacSDimitry Andric     FK = getRelocPairForSize(16);
3617a6dacacSDimitry Andric     support::endian::write<uint16_t>(OS, 0, llvm::endianness::little);
3627a6dacacSDimitry Andric   }
3637a6dacacSDimitry Andric 
3647a6dacacSDimitry Andric   const MCBinaryExpr &MBE = cast<MCBinaryExpr>(AddrDelta);
3657a6dacacSDimitry Andric   Fixups.push_back(MCFixup::create(Offset, MBE.getLHS(), std::get<0>(FK)));
3667a6dacacSDimitry Andric   Fixups.push_back(MCFixup::create(Offset, MBE.getRHS(), std::get<1>(FK)));
3677a6dacacSDimitry Andric 
3687a6dacacSDimitry Andric   if (LineDelta == INT64_MAX) {
3697a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_LNS_extended_op);
3707a6dacacSDimitry Andric     OS << uint8_t(1);
3717a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_LNE_end_sequence);
3727a6dacacSDimitry Andric   } else {
3737a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_LNS_copy);
3747a6dacacSDimitry Andric   }
3757a6dacacSDimitry Andric 
3767a6dacacSDimitry Andric   WasRelaxed = OldSize != Data.size();
3777a6dacacSDimitry Andric   return true;
3787a6dacacSDimitry Andric }
3797a6dacacSDimitry Andric 
380*0fca6ea1SDimitry Andric bool LoongArchAsmBackend::relaxDwarfCFA(const MCAssembler &Asm,
381*0fca6ea1SDimitry Andric                                         MCDwarfCallFrameFragment &DF,
3827a6dacacSDimitry Andric                                         bool &WasRelaxed) const {
3837a6dacacSDimitry Andric   const MCExpr &AddrDelta = DF.getAddrDelta();
3847a6dacacSDimitry Andric   SmallVectorImpl<char> &Data = DF.getContents();
3857a6dacacSDimitry Andric   SmallVectorImpl<MCFixup> &Fixups = DF.getFixups();
3867a6dacacSDimitry Andric   size_t OldSize = Data.size();
3877a6dacacSDimitry Andric 
3887a6dacacSDimitry Andric   int64_t Value;
389*0fca6ea1SDimitry Andric   if (AddrDelta.evaluateAsAbsolute(Value, Asm))
3907a6dacacSDimitry Andric     return false;
391*0fca6ea1SDimitry Andric   bool IsAbsolute = AddrDelta.evaluateKnownAbsolute(Value, Asm);
3927a6dacacSDimitry Andric   assert(IsAbsolute && "CFA with invalid expression");
3937a6dacacSDimitry Andric   (void)IsAbsolute;
3947a6dacacSDimitry Andric 
3957a6dacacSDimitry Andric   Data.clear();
3967a6dacacSDimitry Andric   Fixups.clear();
3977a6dacacSDimitry Andric   raw_svector_ostream OS(Data);
3987a6dacacSDimitry Andric 
399*0fca6ea1SDimitry Andric   assert(Asm.getContext().getAsmInfo()->getMinInstAlignment() == 1 &&
4007a6dacacSDimitry Andric          "expected 1-byte alignment");
4017a6dacacSDimitry Andric   if (Value == 0) {
4027a6dacacSDimitry Andric     WasRelaxed = OldSize != Data.size();
4037a6dacacSDimitry Andric     return true;
4047a6dacacSDimitry Andric   }
4057a6dacacSDimitry Andric 
4067a6dacacSDimitry Andric   auto AddFixups = [&Fixups,
4077a6dacacSDimitry Andric                     &AddrDelta](unsigned Offset,
4087a6dacacSDimitry Andric                                 std::pair<MCFixupKind, MCFixupKind> FK) {
4097a6dacacSDimitry Andric     const MCBinaryExpr &MBE = cast<MCBinaryExpr>(AddrDelta);
4107a6dacacSDimitry Andric     Fixups.push_back(MCFixup::create(Offset, MBE.getLHS(), std::get<0>(FK)));
4117a6dacacSDimitry Andric     Fixups.push_back(MCFixup::create(Offset, MBE.getRHS(), std::get<1>(FK)));
4127a6dacacSDimitry Andric   };
4137a6dacacSDimitry Andric 
4147a6dacacSDimitry Andric   if (isUIntN(6, Value)) {
4157a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_CFA_advance_loc);
4167a6dacacSDimitry Andric     AddFixups(0, getRelocPairForSize(6));
4177a6dacacSDimitry Andric   } else if (isUInt<8>(Value)) {
4187a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_CFA_advance_loc1);
4197a6dacacSDimitry Andric     support::endian::write<uint8_t>(OS, 0, llvm::endianness::little);
4207a6dacacSDimitry Andric     AddFixups(1, getRelocPairForSize(8));
4217a6dacacSDimitry Andric   } else if (isUInt<16>(Value)) {
4227a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_CFA_advance_loc2);
4237a6dacacSDimitry Andric     support::endian::write<uint16_t>(OS, 0, llvm::endianness::little);
4247a6dacacSDimitry Andric     AddFixups(1, getRelocPairForSize(16));
4257a6dacacSDimitry Andric   } else if (isUInt<32>(Value)) {
4267a6dacacSDimitry Andric     OS << uint8_t(dwarf::DW_CFA_advance_loc4);
4277a6dacacSDimitry Andric     support::endian::write<uint32_t>(OS, 0, llvm::endianness::little);
4287a6dacacSDimitry Andric     AddFixups(1, getRelocPairForSize(32));
4297a6dacacSDimitry Andric   } else {
4307a6dacacSDimitry Andric     llvm_unreachable("unsupported CFA encoding");
4317a6dacacSDimitry Andric   }
4327a6dacacSDimitry Andric 
4337a6dacacSDimitry Andric   WasRelaxed = OldSize != Data.size();
4347a6dacacSDimitry Andric   return true;
4357a6dacacSDimitry Andric }
4367a6dacacSDimitry Andric 
43781ad6265SDimitry Andric bool LoongArchAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
43881ad6265SDimitry Andric                                        const MCSubtargetInfo *STI) const {
439bdd1243dSDimitry Andric   // We mostly follow binutils' convention here: align to 4-byte boundary with a
440bdd1243dSDimitry Andric   // 0-fill padding.
441bdd1243dSDimitry Andric   OS.write_zeros(Count % 4);
44281ad6265SDimitry Andric 
443bdd1243dSDimitry Andric   // The remainder is now padded with 4-byte nops.
444bdd1243dSDimitry Andric   // nop: andi r0, r0, 0
44581ad6265SDimitry Andric   for (; Count >= 4; Count -= 4)
446bdd1243dSDimitry Andric     OS.write("\0\0\x40\x03", 4);
44781ad6265SDimitry Andric 
44881ad6265SDimitry Andric   return true;
44981ad6265SDimitry Andric }
45081ad6265SDimitry Andric 
451*0fca6ea1SDimitry Andric bool LoongArchAsmBackend::handleAddSubRelocations(const MCAssembler &Asm,
452cb14a3feSDimitry Andric                                                   const MCFragment &F,
453cb14a3feSDimitry Andric                                                   const MCFixup &Fixup,
454cb14a3feSDimitry Andric                                                   const MCValue &Target,
455cb14a3feSDimitry Andric                                                   uint64_t &FixedValue) const {
456cb14a3feSDimitry Andric   std::pair<MCFixupKind, MCFixupKind> FK;
457cb14a3feSDimitry Andric   uint64_t FixedValueA, FixedValueB;
4581db9f3b2SDimitry Andric   const MCSymbol &SA = Target.getSymA()->getSymbol();
4591db9f3b2SDimitry Andric   const MCSymbol &SB = Target.getSymB()->getSymbol();
4601db9f3b2SDimitry Andric 
4611db9f3b2SDimitry Andric   bool force = !SA.isInSection() || !SB.isInSection();
4621db9f3b2SDimitry Andric   if (!force) {
4631db9f3b2SDimitry Andric     const MCSection &SecA = SA.getSection();
4641db9f3b2SDimitry Andric     const MCSection &SecB = SB.getSection();
465cb14a3feSDimitry Andric 
466cb14a3feSDimitry Andric     // We need record relocation if SecA != SecB. Usually SecB is same as the
467cb14a3feSDimitry Andric     // section of Fixup, which will be record the relocation as PCRel. If SecB
468cb14a3feSDimitry Andric     // is not same as the section of Fixup, it will report error. Just return
469cb14a3feSDimitry Andric     // false and then this work can be finished by handleFixup.
470cb14a3feSDimitry Andric     if (&SecA != &SecB)
471cb14a3feSDimitry Andric       return false;
472cb14a3feSDimitry Andric 
473cb14a3feSDimitry Andric     // In SecA == SecB case. If the linker relaxation is enabled, we need record
4741db9f3b2SDimitry Andric     // the ADD, SUB relocations. Otherwise the FixedValue has already been calc-
4751db9f3b2SDimitry Andric     // ulated out in evaluateFixup, return true and avoid record relocations.
476cb14a3feSDimitry Andric     if (!STI.hasFeature(LoongArch::FeatureRelax))
477cb14a3feSDimitry Andric       return true;
4781db9f3b2SDimitry Andric   }
479cb14a3feSDimitry Andric 
480cb14a3feSDimitry Andric   switch (Fixup.getKind()) {
481cb14a3feSDimitry Andric   case llvm::FK_Data_1:
482cb14a3feSDimitry Andric     FK = getRelocPairForSize(8);
483cb14a3feSDimitry Andric     break;
484cb14a3feSDimitry Andric   case llvm::FK_Data_2:
485cb14a3feSDimitry Andric     FK = getRelocPairForSize(16);
486cb14a3feSDimitry Andric     break;
487cb14a3feSDimitry Andric   case llvm::FK_Data_4:
488cb14a3feSDimitry Andric     FK = getRelocPairForSize(32);
489cb14a3feSDimitry Andric     break;
490cb14a3feSDimitry Andric   case llvm::FK_Data_8:
491cb14a3feSDimitry Andric     FK = getRelocPairForSize(64);
492cb14a3feSDimitry Andric     break;
4931db9f3b2SDimitry Andric   case llvm::FK_Data_leb128:
4941db9f3b2SDimitry Andric     FK = getRelocPairForSize(128);
4951db9f3b2SDimitry Andric     break;
496cb14a3feSDimitry Andric   default:
497cb14a3feSDimitry Andric     llvm_unreachable("unsupported fixup size");
498cb14a3feSDimitry Andric   }
499cb14a3feSDimitry Andric   MCValue A = MCValue::get(Target.getSymA(), nullptr, Target.getConstant());
500cb14a3feSDimitry Andric   MCValue B = MCValue::get(Target.getSymB());
501cb14a3feSDimitry Andric   auto FA = MCFixup::create(Fixup.getOffset(), nullptr, std::get<0>(FK));
502cb14a3feSDimitry Andric   auto FB = MCFixup::create(Fixup.getOffset(), nullptr, std::get<1>(FK));
503*0fca6ea1SDimitry Andric   auto &Assembler = const_cast<MCAssembler &>(Asm);
504*0fca6ea1SDimitry Andric   Asm.getWriter().recordRelocation(Assembler, &F, FA, A, FixedValueA);
505*0fca6ea1SDimitry Andric   Asm.getWriter().recordRelocation(Assembler, &F, FB, B, FixedValueB);
506cb14a3feSDimitry Andric   FixedValue = FixedValueA - FixedValueB;
507cb14a3feSDimitry Andric   return true;
508cb14a3feSDimitry Andric }
509cb14a3feSDimitry Andric 
51081ad6265SDimitry Andric std::unique_ptr<MCObjectTargetWriter>
51181ad6265SDimitry Andric LoongArchAsmBackend::createObjectTargetWriter() const {
5125f757f3fSDimitry Andric   return createLoongArchELFObjectWriter(
5135f757f3fSDimitry Andric       OSABI, Is64Bit, STI.hasFeature(LoongArch::FeatureRelax));
51481ad6265SDimitry Andric }
51581ad6265SDimitry Andric 
51681ad6265SDimitry Andric MCAsmBackend *llvm::createLoongArchAsmBackend(const Target &T,
51781ad6265SDimitry Andric                                               const MCSubtargetInfo &STI,
51881ad6265SDimitry Andric                                               const MCRegisterInfo &MRI,
51981ad6265SDimitry Andric                                               const MCTargetOptions &Options) {
52081ad6265SDimitry Andric   const Triple &TT = STI.getTargetTriple();
52181ad6265SDimitry Andric   uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TT.getOS());
52206c3fb27SDimitry Andric   return new LoongArchAsmBackend(STI, OSABI, TT.isArch64Bit(), Options);
52381ad6265SDimitry Andric }
524