xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Sparc/MCTargetDesc/SparcMCCodeEmitter.cpp (revision d5b0e70f7e04d971691517ce1304d86a1e367e2e)
1 //===-- SparcMCCodeEmitter.cpp - Convert Sparc code to machine code -------===//
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 implements the SparcMCCodeEmitter class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "MCTargetDesc/SparcFixupKinds.h"
14 #include "SparcMCExpr.h"
15 #include "SparcMCTargetDesc.h"
16 #include "llvm/ADT/SmallVector.h"
17 #include "llvm/ADT/Statistic.h"
18 #include "llvm/MC/MCAsmInfo.h"
19 #include "llvm/MC/MCCodeEmitter.h"
20 #include "llvm/MC/MCContext.h"
21 #include "llvm/MC/MCExpr.h"
22 #include "llvm/MC/MCFixup.h"
23 #include "llvm/MC/MCInst.h"
24 #include "llvm/MC/MCInstrInfo.h"
25 #include "llvm/MC/MCObjectFileInfo.h"
26 #include "llvm/MC/MCRegisterInfo.h"
27 #include "llvm/MC/MCSubtargetInfo.h"
28 #include "llvm/MC/MCSymbol.h"
29 #include "llvm/MC/SubtargetFeature.h"
30 #include "llvm/Support/Casting.h"
31 #include "llvm/Support/Endian.h"
32 #include "llvm/Support/EndianStream.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/raw_ostream.h"
35 #include <cassert>
36 #include <cstdint>
37 
38 using namespace llvm;
39 
40 #define DEBUG_TYPE "mccodeemitter"
41 
42 STATISTIC(MCNumEmitted, "Number of MC instructions emitted");
43 
44 namespace {
45 
46 class SparcMCCodeEmitter : public MCCodeEmitter {
47   const MCInstrInfo &MCII;
48   MCContext &Ctx;
49 
50 public:
51   SparcMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx)
52       : MCII(mcii), Ctx(ctx) {}
53   SparcMCCodeEmitter(const SparcMCCodeEmitter &) = delete;
54   SparcMCCodeEmitter &operator=(const SparcMCCodeEmitter &) = delete;
55   ~SparcMCCodeEmitter() override = default;
56 
57   void encodeInstruction(const MCInst &MI, raw_ostream &OS,
58                          SmallVectorImpl<MCFixup> &Fixups,
59                          const MCSubtargetInfo &STI) const override;
60 
61   // getBinaryCodeForInstr - TableGen'erated function for getting the
62   // binary encoding for an instruction.
63   uint64_t getBinaryCodeForInstr(const MCInst &MI,
64                                  SmallVectorImpl<MCFixup> &Fixups,
65                                  const MCSubtargetInfo &STI) const;
66 
67   /// getMachineOpValue - Return binary encoding of operand. If the machine
68   /// operand requires relocation, record the relocation and return zero.
69   unsigned getMachineOpValue(const MCInst &MI, const MCOperand &MO,
70                              SmallVectorImpl<MCFixup> &Fixups,
71                              const MCSubtargetInfo &STI) const;
72   unsigned getCallTargetOpValue(const MCInst &MI, unsigned OpNo,
73                              SmallVectorImpl<MCFixup> &Fixups,
74                              const MCSubtargetInfo &STI) const;
75   unsigned getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
76                              SmallVectorImpl<MCFixup> &Fixups,
77                              const MCSubtargetInfo &STI) const;
78   unsigned getSImm13OpValue(const MCInst &MI, unsigned OpNo,
79                             SmallVectorImpl<MCFixup> &Fixups,
80                             const MCSubtargetInfo &STI) const;
81   unsigned getBranchPredTargetOpValue(const MCInst &MI, unsigned OpNo,
82                                       SmallVectorImpl<MCFixup> &Fixups,
83                                       const MCSubtargetInfo &STI) const;
84   unsigned getBranchOnRegTargetOpValue(const MCInst &MI, unsigned OpNo,
85                                        SmallVectorImpl<MCFixup> &Fixups,
86                                        const MCSubtargetInfo &STI) const;
87 
88 private:
89   FeatureBitset computeAvailableFeatures(const FeatureBitset &FB) const;
90   void
91   verifyInstructionPredicates(const MCInst &MI,
92                               const FeatureBitset &AvailableFeatures) const;
93 };
94 
95 } // end anonymous namespace
96 
97 void SparcMCCodeEmitter::encodeInstruction(const MCInst &MI, raw_ostream &OS,
98                                            SmallVectorImpl<MCFixup> &Fixups,
99                                            const MCSubtargetInfo &STI) const {
100   verifyInstructionPredicates(MI,
101                               computeAvailableFeatures(STI.getFeatureBits()));
102 
103   unsigned Bits = getBinaryCodeForInstr(MI, Fixups, STI);
104   support::endian::write(OS, Bits,
105                          Ctx.getAsmInfo()->isLittleEndian() ? support::little
106                                                             : support::big);
107   unsigned tlsOpNo = 0;
108   switch (MI.getOpcode()) {
109   default: break;
110   case SP::TLS_CALL:   tlsOpNo = 1; break;
111   case SP::TLS_ADDrr:
112   case SP::TLS_ADDXrr:
113   case SP::TLS_LDrr:
114   case SP::TLS_LDXrr:  tlsOpNo = 3; break;
115   }
116   if (tlsOpNo != 0) {
117     const MCOperand &MO = MI.getOperand(tlsOpNo);
118     uint64_t op = getMachineOpValue(MI, MO, Fixups, STI);
119     assert(op == 0 && "Unexpected operand value!");
120     (void)op; // suppress warning.
121   }
122 
123   ++MCNumEmitted;  // Keep track of the # of mi's emitted.
124 }
125 
126 unsigned SparcMCCodeEmitter::
127 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
128                   SmallVectorImpl<MCFixup> &Fixups,
129                   const MCSubtargetInfo &STI) const {
130   if (MO.isReg())
131     return Ctx.getRegisterInfo()->getEncodingValue(MO.getReg());
132 
133   if (MO.isImm())
134     return MO.getImm();
135 
136   assert(MO.isExpr());
137   const MCExpr *Expr = MO.getExpr();
138   if (const SparcMCExpr *SExpr = dyn_cast<SparcMCExpr>(Expr)) {
139     MCFixupKind Kind = (MCFixupKind)SExpr->getFixupKind();
140     Fixups.push_back(MCFixup::create(0, Expr, Kind));
141     return 0;
142   }
143 
144   int64_t Res;
145   if (Expr->evaluateAsAbsolute(Res))
146     return Res;
147 
148   llvm_unreachable("Unhandled expression!");
149   return 0;
150 }
151 
152 unsigned
153 SparcMCCodeEmitter::getSImm13OpValue(const MCInst &MI, unsigned OpNo,
154                                      SmallVectorImpl<MCFixup> &Fixups,
155                                      const MCSubtargetInfo &STI) const {
156   const MCOperand &MO = MI.getOperand(OpNo);
157 
158   if (MO.isImm())
159     return MO.getImm();
160 
161   assert(MO.isExpr() &&
162          "getSImm13OpValue expects only expressions or an immediate");
163 
164   const MCExpr *Expr = MO.getExpr();
165 
166   // Constant value, no fixup is needed
167   if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Expr))
168     return CE->getValue();
169 
170   MCFixupKind Kind;
171   if (const SparcMCExpr *SExpr = dyn_cast<SparcMCExpr>(Expr)) {
172     Kind = MCFixupKind(SExpr->getFixupKind());
173   } else {
174     bool IsPic = Ctx.getObjectFileInfo()->isPositionIndependent();
175     Kind = IsPic ? MCFixupKind(Sparc::fixup_sparc_got13)
176                  : MCFixupKind(Sparc::fixup_sparc_13);
177   }
178 
179   Fixups.push_back(MCFixup::create(0, Expr, Kind));
180   return 0;
181 }
182 
183 unsigned SparcMCCodeEmitter::
184 getCallTargetOpValue(const MCInst &MI, unsigned OpNo,
185                      SmallVectorImpl<MCFixup> &Fixups,
186                      const MCSubtargetInfo &STI) const {
187   const MCOperand &MO = MI.getOperand(OpNo);
188   const MCExpr *Expr = MO.getExpr();
189   const SparcMCExpr *SExpr = dyn_cast<SparcMCExpr>(Expr);
190 
191   if (MI.getOpcode() == SP::TLS_CALL) {
192     // No fixups for __tls_get_addr. Will emit for fixups for tls_symbol in
193     // encodeInstruction.
194 #ifndef NDEBUG
195     // Verify that the callee is actually __tls_get_addr.
196     assert(SExpr && SExpr->getSubExpr()->getKind() == MCExpr::SymbolRef &&
197            "Unexpected expression in TLS_CALL");
198     const MCSymbolRefExpr *SymExpr = cast<MCSymbolRefExpr>(SExpr->getSubExpr());
199     assert(SymExpr->getSymbol().getName() == "__tls_get_addr" &&
200            "Unexpected function for TLS_CALL");
201 #endif
202     return 0;
203   }
204 
205   MCFixupKind Kind = MCFixupKind(SExpr->getFixupKind());
206   Fixups.push_back(MCFixup::create(0, Expr, Kind));
207   return 0;
208 }
209 
210 unsigned SparcMCCodeEmitter::
211 getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
212                   SmallVectorImpl<MCFixup> &Fixups,
213                   const MCSubtargetInfo &STI) const {
214   const MCOperand &MO = MI.getOperand(OpNo);
215   if (MO.isReg() || MO.isImm())
216     return getMachineOpValue(MI, MO, Fixups, STI);
217 
218   Fixups.push_back(MCFixup::create(0, MO.getExpr(),
219                                    (MCFixupKind)Sparc::fixup_sparc_br22));
220   return 0;
221 }
222 
223 unsigned SparcMCCodeEmitter::
224 getBranchPredTargetOpValue(const MCInst &MI, unsigned OpNo,
225                            SmallVectorImpl<MCFixup> &Fixups,
226                            const MCSubtargetInfo &STI) const {
227   const MCOperand &MO = MI.getOperand(OpNo);
228   if (MO.isReg() || MO.isImm())
229     return getMachineOpValue(MI, MO, Fixups, STI);
230 
231   Fixups.push_back(MCFixup::create(0, MO.getExpr(),
232                                    (MCFixupKind)Sparc::fixup_sparc_br19));
233   return 0;
234 }
235 
236 unsigned SparcMCCodeEmitter::
237 getBranchOnRegTargetOpValue(const MCInst &MI, unsigned OpNo,
238                            SmallVectorImpl<MCFixup> &Fixups,
239                            const MCSubtargetInfo &STI) const {
240   const MCOperand &MO = MI.getOperand(OpNo);
241   if (MO.isReg() || MO.isImm())
242     return getMachineOpValue(MI, MO, Fixups, STI);
243 
244   Fixups.push_back(MCFixup::create(0, MO.getExpr(),
245                                    (MCFixupKind)Sparc::fixup_sparc_br16_2));
246   Fixups.push_back(MCFixup::create(0, MO.getExpr(),
247                                    (MCFixupKind)Sparc::fixup_sparc_br16_14));
248 
249   return 0;
250 }
251 
252 #define ENABLE_INSTR_PREDICATE_VERIFIER
253 #include "SparcGenMCCodeEmitter.inc"
254 
255 MCCodeEmitter *llvm::createSparcMCCodeEmitter(const MCInstrInfo &MCII,
256                                               const MCRegisterInfo &MRI,
257                                               MCContext &Ctx) {
258   return new SparcMCCodeEmitter(MCII, Ctx);
259 }
260