1//===-- LoongArchMCExpr.cpp - LoongArch specific MC expression classes ----===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file contains the implementation of the assembly expression modifiers
10// accepted by the LoongArch architecture.
11//
12//===----------------------------------------------------------------------===//
13
14#include "LoongArchMCExpr.h"
15#include "LoongArchAsmBackend.h"
16#include "LoongArchFixupKinds.h"
17#include "llvm/MC/MCContext.h"
18#include "llvm/MC/MCStreamer.h"
19#include "llvm/MC/MCSymbolELF.h"
20#include "llvm/MC/MCValue.h"
21#include "llvm/Support/Casting.h"
22#include "llvm/Support/ErrorHandling.h"
23
24using namespace llvm;
25
26#define DEBUG_TYPE "loongarch-mcexpr"
27
28const LoongArchMCExpr *LoongArchMCExpr::create(const MCExpr *Expr,
29                                               VariantKind Kind, MCContext &Ctx,
30                                               bool Hint) {
31  return new (Ctx) LoongArchMCExpr(Expr, Kind, Hint);
32}
33
34void LoongArchMCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
35  VariantKind Kind = getKind();
36  bool HasVariant =
37      ((Kind != VK_LoongArch_None) && (Kind != VK_LoongArch_CALL));
38
39  if (HasVariant)
40    OS << '%' << getVariantKindName(getKind()) << '(';
41  Expr->print(OS, MAI);
42  if (HasVariant)
43    OS << ')';
44}
45
46bool LoongArchMCExpr::evaluateAsRelocatableImpl(MCValue &Res,
47                                                const MCAsmLayout *Layout,
48                                                const MCFixup *Fixup) const {
49  // Explicitly drop the layout and assembler to prevent any symbolic folding in
50  // the expression handling.  This is required to preserve symbolic difference
51  // expressions to emit the paired relocations.
52  if (!getSubExpr()->evaluateAsRelocatable(Res, nullptr, nullptr))
53    return false;
54
55  Res =
56      MCValue::get(Res.getSymA(), Res.getSymB(), Res.getConstant(), getKind());
57  // Custom fixup types are not valid with symbol difference expressions.
58  return Res.getSymB() ? getKind() == VK_LoongArch_None : true;
59}
60
61void LoongArchMCExpr::visitUsedExpr(MCStreamer &Streamer) const {
62  Streamer.visitUsedExpr(*getSubExpr());
63}
64
65StringRef LoongArchMCExpr::getVariantKindName(VariantKind Kind) {
66  switch (Kind) {
67  default:
68    llvm_unreachable("Invalid ELF symbol kind");
69  case VK_LoongArch_CALL_PLT:
70    return "plt";
71  case VK_LoongArch_B16:
72    return "b16";
73  case VK_LoongArch_B21:
74    return "b21";
75  case VK_LoongArch_B26:
76    return "b21";
77  case VK_LoongArch_ABS_HI20:
78    return "abs_hi20";
79  case VK_LoongArch_ABS_LO12:
80    return "abs_lo12";
81  case VK_LoongArch_ABS64_LO20:
82    return "abs64_lo20";
83  case VK_LoongArch_ABS64_HI12:
84    return "abs64_hi12";
85  case VK_LoongArch_PCALA_HI20:
86    return "pc_hi20";
87  case VK_LoongArch_PCALA_LO12:
88    return "pc_lo12";
89  case VK_LoongArch_PCALA64_LO20:
90    return "pc64_lo20";
91  case VK_LoongArch_PCALA64_HI12:
92    return "pc64_hi12";
93  case VK_LoongArch_GOT_PC_HI20:
94    return "got_pc_hi20";
95  case VK_LoongArch_GOT_PC_LO12:
96    return "got_pc_lo12";
97  case VK_LoongArch_GOT64_PC_LO20:
98    return "got64_pc_lo20";
99  case VK_LoongArch_GOT64_PC_HI12:
100    return "got64_pc_hi12";
101  case VK_LoongArch_GOT_HI20:
102    return "got_hi20";
103  case VK_LoongArch_GOT_LO12:
104    return "got_lo12";
105  case VK_LoongArch_GOT64_LO20:
106    return "got64_lo20";
107  case VK_LoongArch_GOT64_HI12:
108    return "got64_hi12";
109  case VK_LoongArch_TLS_LE_HI20:
110    return "le_hi20";
111  case VK_LoongArch_TLS_LE_LO12:
112    return "le_lo12";
113  case VK_LoongArch_TLS_LE64_LO20:
114    return "le64_lo20";
115  case VK_LoongArch_TLS_LE64_HI12:
116    return "le64_hi12";
117  case VK_LoongArch_TLS_IE_PC_HI20:
118    return "ie_pc_hi20";
119  case VK_LoongArch_TLS_IE_PC_LO12:
120    return "ie_pc_lo12";
121  case VK_LoongArch_TLS_IE64_PC_LO20:
122    return "ie64_pc_lo20";
123  case VK_LoongArch_TLS_IE64_PC_HI12:
124    return "ie64_pc_hi12";
125  case VK_LoongArch_TLS_IE_HI20:
126    return "ie_hi20";
127  case VK_LoongArch_TLS_IE_LO12:
128    return "ie_lo12";
129  case VK_LoongArch_TLS_IE64_LO20:
130    return "ie64_lo20";
131  case VK_LoongArch_TLS_IE64_HI12:
132    return "ie64_hi12";
133  case VK_LoongArch_TLS_LD_PC_HI20:
134    return "ld_pc_hi20";
135  case VK_LoongArch_TLS_LD_HI20:
136    return "ld_hi20";
137  case VK_LoongArch_TLS_GD_PC_HI20:
138    return "gd_pc_hi20";
139  case VK_LoongArch_TLS_GD_HI20:
140    return "gd_hi20";
141  case VK_LoongArch_CALL36:
142    return "call36";
143  }
144}
145
146LoongArchMCExpr::VariantKind
147LoongArchMCExpr::getVariantKindForName(StringRef name) {
148  return StringSwitch<LoongArchMCExpr::VariantKind>(name)
149      .Case("plt", VK_LoongArch_CALL_PLT)
150      .Case("b16", VK_LoongArch_B16)
151      .Case("b21", VK_LoongArch_B21)
152      .Case("b26", VK_LoongArch_B26)
153      .Case("abs_hi20", VK_LoongArch_ABS_HI20)
154      .Case("abs_lo12", VK_LoongArch_ABS_LO12)
155      .Case("abs64_lo20", VK_LoongArch_ABS64_LO20)
156      .Case("abs64_hi12", VK_LoongArch_ABS64_HI12)
157      .Case("pc_hi20", VK_LoongArch_PCALA_HI20)
158      .Case("pc_lo12", VK_LoongArch_PCALA_LO12)
159      .Case("pc64_lo20", VK_LoongArch_PCALA64_LO20)
160      .Case("pc64_hi12", VK_LoongArch_PCALA64_HI12)
161      .Case("got_pc_hi20", VK_LoongArch_GOT_PC_HI20)
162      .Case("got_pc_lo12", VK_LoongArch_GOT_PC_LO12)
163      .Case("got64_pc_lo20", VK_LoongArch_GOT64_PC_LO20)
164      .Case("got64_pc_hi12", VK_LoongArch_GOT64_PC_HI12)
165      .Case("got_hi20", VK_LoongArch_GOT_HI20)
166      .Case("got_lo12", VK_LoongArch_GOT_LO12)
167      .Case("got64_lo20", VK_LoongArch_GOT64_LO20)
168      .Case("got64_hi12", VK_LoongArch_GOT64_HI12)
169      .Case("le_hi20", VK_LoongArch_TLS_LE_HI20)
170      .Case("le_lo12", VK_LoongArch_TLS_LE_LO12)
171      .Case("le64_lo20", VK_LoongArch_TLS_LE64_LO20)
172      .Case("le64_hi12", VK_LoongArch_TLS_LE64_HI12)
173      .Case("ie_pc_hi20", VK_LoongArch_TLS_IE_PC_HI20)
174      .Case("ie_pc_lo12", VK_LoongArch_TLS_IE_PC_LO12)
175      .Case("ie64_pc_lo20", VK_LoongArch_TLS_IE64_PC_LO20)
176      .Case("ie64_pc_hi12", VK_LoongArch_TLS_IE64_PC_HI12)
177      .Case("ie_hi20", VK_LoongArch_TLS_IE_HI20)
178      .Case("ie_lo12", VK_LoongArch_TLS_IE_LO12)
179      .Case("ie64_lo20", VK_LoongArch_TLS_IE64_LO20)
180      .Case("ie64_hi12", VK_LoongArch_TLS_IE64_HI12)
181      .Case("ld_pc_hi20", VK_LoongArch_TLS_LD_PC_HI20)
182      .Case("ld_hi20", VK_LoongArch_TLS_LD_HI20)
183      .Case("gd_pc_hi20", VK_LoongArch_TLS_GD_PC_HI20)
184      .Case("gd_hi20", VK_LoongArch_TLS_GD_HI20)
185      .Case("call36", VK_LoongArch_CALL36)
186      .Default(VK_LoongArch_Invalid);
187}
188
189static void fixELFSymbolsInTLSFixupsImpl(const MCExpr *Expr, MCAssembler &Asm) {
190  switch (Expr->getKind()) {
191  case MCExpr::Target:
192    llvm_unreachable("Can't handle nested target expression");
193    break;
194  case MCExpr::Constant:
195    break;
196  case MCExpr::Unary:
197    fixELFSymbolsInTLSFixupsImpl(cast<MCUnaryExpr>(Expr)->getSubExpr(), Asm);
198    break;
199  case MCExpr::Binary: {
200    const MCBinaryExpr *BE = cast<MCBinaryExpr>(Expr);
201    fixELFSymbolsInTLSFixupsImpl(BE->getLHS(), Asm);
202    fixELFSymbolsInTLSFixupsImpl(BE->getRHS(), Asm);
203    break;
204  }
205  case MCExpr::SymbolRef: {
206    // We're known to be under a TLS fixup, so any symbol should be
207    // modified. There should be only one.
208    const MCSymbolRefExpr &SymRef = *cast<MCSymbolRefExpr>(Expr);
209    cast<MCSymbolELF>(SymRef.getSymbol()).setType(ELF::STT_TLS);
210    break;
211  }
212  }
213}
214
215void LoongArchMCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const {
216  switch (getKind()) {
217  default:
218    return;
219  case VK_LoongArch_TLS_LE_HI20:
220  case VK_LoongArch_TLS_IE_PC_HI20:
221  case VK_LoongArch_TLS_IE_HI20:
222  case VK_LoongArch_TLS_LD_PC_HI20:
223  case VK_LoongArch_TLS_LD_HI20:
224  case VK_LoongArch_TLS_GD_PC_HI20:
225  case VK_LoongArch_TLS_GD_HI20:
226    break;
227  }
228  fixELFSymbolsInTLSFixupsImpl(getSubExpr(), Asm);
229}
230