1//===-- MipsSubtarget.cpp - Mips Subtarget Information --------------------===//
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 Mips specific subclass of TargetSubtargetInfo.
10//
11//===----------------------------------------------------------------------===//
12
13#include "MipsSubtarget.h"
14#include "Mips.h"
15#include "MipsCallLowering.h"
16#include "MipsLegalizerInfo.h"
17#include "MipsMachineFunction.h"
18#include "MipsRegisterBankInfo.h"
19#include "MipsRegisterInfo.h"
20#include "MipsTargetMachine.h"
21#include "llvm/IR/Attributes.h"
22#include "llvm/IR/Function.h"
23#include "llvm/MC/TargetRegistry.h"
24#include "llvm/Support/CommandLine.h"
25#include "llvm/Support/Debug.h"
26#include "llvm/Support/raw_ostream.h"
27
28using namespace llvm;
29
30#define DEBUG_TYPE "mips-subtarget"
31
32#define GET_SUBTARGETINFO_TARGET_DESC
33#define GET_SUBTARGETINFO_CTOR
34#include "MipsGenSubtargetInfo.inc"
35
36// FIXME: Maybe this should be on by default when Mips16 is specified
37//
38static cl::opt<bool>
39 Mixed16_32("mips-mixed-16-32", cl::init(Val: false),
40 cl::desc("Allow for a mixture of Mips16 "
41 "and Mips32 code in a single output file"),
42 cl::Hidden);
43
44static cl::opt<bool> Mips_Os16("mips-os16", cl::init(Val: false),
45 cl::desc("Compile all functions that don't use "
46 "floating point as Mips 16"),
47 cl::Hidden);
48
49static cl::opt<bool> Mips16HardFloat("mips16-hard-float", cl::NotHidden,
50 cl::desc("Enable mips16 hard float."),
51 cl::init(Val: false));
52
53static cl::opt<bool>
54 Mips16ConstantIslands("mips16-constant-islands", cl::NotHidden,
55 cl::desc("Enable mips16 constant islands."),
56 cl::init(Val: true));
57
58static cl::opt<bool>
59 GPOpt("mgpopt", cl::Hidden,
60 cl::desc("Enable gp-relative addressing of mips small data items"));
61
62bool MipsSubtarget::DspWarningPrinted = false;
63bool MipsSubtarget::MSAWarningPrinted = false;
64bool MipsSubtarget::VirtWarningPrinted = false;
65bool MipsSubtarget::CRCWarningPrinted = false;
66bool MipsSubtarget::GINVWarningPrinted = false;
67bool MipsSubtarget::MIPS1WarningPrinted = false;
68
69void MipsSubtarget::anchor() {}
70
71MipsSubtarget::MipsSubtarget(const Triple &TT, StringRef CPU, StringRef FS,
72 bool little, const MipsTargetMachine &TM,
73 MaybeAlign StackAlignOverride)
74 : MipsGenSubtargetInfo(TT, CPU, /*TuneCPU*/ CPU, FS),
75 MipsArchVersion(MipsDefault), IsLittle(little), IsSoftFloat(false),
76 IsSingleFloat(false), IsFPXX(false), NoABICalls(false), Abs2008(false),
77 IsFP64bit(false), UseOddSPReg(true), IsNaN2008bit(false),
78 IsGP64bit(false), HasVFPU(false), HasCnMips(false), HasCnMipsP(false),
79 HasMips3_32(false), HasMips3_32r2(false), HasMips4_32(false),
80 HasMips4_32r2(false), HasMips5_32r2(false), InMips16Mode(false),
81 InMips16HardFloat(Mips16HardFloat), InMicroMipsMode(false), HasDSP(false),
82 HasDSPR2(false), HasDSPR3(false), AllowMixed16_32(Mixed16_32 || Mips_Os16),
83 Os16(Mips_Os16), HasMSA(false), UseTCCInDIV(false), HasSym32(false),
84 HasEVA(false), DisableMadd4(false), HasMT(false), HasCRC(false),
85 HasVirt(false), HasGINV(false), UseIndirectJumpsHazard(false), StrictAlign(false),
86 StackAlignOverride(StackAlignOverride), TM(TM), TargetTriple(TT),
87 TSInfo(), InstrInfo(MipsInstrInfo::create(
88 STI&: initializeSubtargetDependencies(CPU, FS, TM))),
89 FrameLowering(MipsFrameLowering::create(ST: *this)),
90 TLInfo(MipsTargetLowering::create(TM, STI: *this)) {
91
92 if (MipsArchVersion == MipsDefault)
93 MipsArchVersion = Mips32;
94
95 // MIPS-I has not been tested.
96 if (MipsArchVersion == Mips1 && !MIPS1WarningPrinted) {
97 errs() << "warning: MIPS-I support is experimental\n";
98 MIPS1WarningPrinted = true;
99 }
100
101 // Don't even attempt to generate code for MIPS-V. It has not
102 // been tested and currently exists for the integrated assembler only.
103 if (MipsArchVersion == Mips5)
104 report_fatal_error(reason: "Code generation for MIPS-V is not implemented", gen_crash_diag: false);
105
106 // Check if Architecture and ABI are compatible.
107 assert(((!isGP64bit() && isABI_O32()) || isGP64bit()) &&
108 "Invalid Arch & ABI pair.");
109
110 if (hasMSA() && !isFP64bit())
111 report_fatal_error(reason: "MSA requires a 64-bit FPU register file (FR=1 mode). "
112 "See -mattr=+fp64.",
113 gen_crash_diag: false);
114
115 if (isFP64bit() && !hasMips64() && hasMips32() && !hasMips32r2())
116 report_fatal_error(
117 reason: "FPU with 64-bit registers is not available on MIPS32 pre revision 2. "
118 "Use -mcpu=mips32r2 or greater.", gen_crash_diag: false);
119
120 if (!isABI_O32() && !useOddSPReg())
121 report_fatal_error(reason: "-mattr=+nooddspreg requires the O32 ABI.", gen_crash_diag: false);
122
123 if (IsFPXX && (isABI_N32() || isABI_N64()))
124 report_fatal_error(reason: "FPXX is not permitted for the N32/N64 ABI's.", gen_crash_diag: false);
125
126 if (hasMips64r6() && InMicroMipsMode)
127 report_fatal_error(reason: "microMIPS64R6 is not supported", gen_crash_diag: false);
128
129 if (!isABI_O32() && InMicroMipsMode)
130 report_fatal_error(reason: "microMIPS64 is not supported.", gen_crash_diag: false);
131
132 if (UseIndirectJumpsHazard) {
133 if (InMicroMipsMode)
134 report_fatal_error(
135 reason: "cannot combine indirect jumps with hazard barriers and microMIPS");
136 if (!hasMips32r2())
137 report_fatal_error(
138 reason: "indirect jumps with hazard barriers requires MIPS32R2 or later");
139 }
140 if (inAbs2008Mode() && hasMips32() && !hasMips32r2()) {
141 report_fatal_error(reason: "IEEE 754-2008 abs.fmt is not supported for the given "
142 "architecture.",
143 gen_crash_diag: false);
144 }
145
146 if (hasMips32r6()) {
147 StringRef ISA = hasMips64r6() ? "MIPS64r6" : "MIPS32r6";
148
149 assert(isFP64bit());
150 assert(isNaN2008());
151 assert(inAbs2008Mode());
152 if (hasDSP())
153 report_fatal_error(reason: ISA + " is not compatible with the DSP ASE", gen_crash_diag: false);
154 }
155
156 if (NoABICalls && TM.isPositionIndependent())
157 report_fatal_error(reason: "position-independent code requires '-mabicalls'");
158
159 if (isABI_N64() && !TM.isPositionIndependent() && !hasSym32())
160 NoABICalls = true;
161
162 // Set UseSmallSection.
163 UseSmallSection = GPOpt;
164 if (!NoABICalls && GPOpt) {
165 errs() << "warning: cannot use small-data accesses for '-mabicalls'"
166 << "\n";
167 UseSmallSection = false;
168 }
169
170 if (hasDSPR2() && !DspWarningPrinted) {
171 if (hasMips64() && !hasMips64r2()) {
172 errs() << "warning: the 'dspr2' ASE requires MIPS64 revision 2 or "
173 << "greater\n";
174 DspWarningPrinted = true;
175 } else if (hasMips32() && !hasMips32r2()) {
176 errs() << "warning: the 'dspr2' ASE requires MIPS32 revision 2 or "
177 << "greater\n";
178 DspWarningPrinted = true;
179 }
180 } else if (hasDSP() && !DspWarningPrinted) {
181 if (hasMips64() && !hasMips64r2()) {
182 errs() << "warning: the 'dsp' ASE requires MIPS64 revision 2 or "
183 << "greater\n";
184 DspWarningPrinted = true;
185 } else if (hasMips32() && !hasMips32r2()) {
186 errs() << "warning: the 'dsp' ASE requires MIPS32 revision 2 or "
187 << "greater\n";
188 DspWarningPrinted = true;
189 }
190 }
191
192 StringRef ArchName = hasMips64() ? "MIPS64" : "MIPS32";
193
194 if (!hasMips32r5() && hasMSA() && !MSAWarningPrinted) {
195 errs() << "warning: the 'msa' ASE requires " << ArchName
196 << " revision 5 or greater\n";
197 MSAWarningPrinted = true;
198 }
199 if (!hasMips32r5() && hasVirt() && !VirtWarningPrinted) {
200 errs() << "warning: the 'virt' ASE requires " << ArchName
201 << " revision 5 or greater\n";
202 VirtWarningPrinted = true;
203 }
204 if (!hasMips32r6() && hasCRC() && !CRCWarningPrinted) {
205 errs() << "warning: the 'crc' ASE requires " << ArchName
206 << " revision 6 or greater\n";
207 CRCWarningPrinted = true;
208 }
209 if (!hasMips32r6() && hasGINV() && !GINVWarningPrinted) {
210 errs() << "warning: the 'ginv' ASE requires " << ArchName
211 << " revision 6 or greater\n";
212 GINVWarningPrinted = true;
213 }
214
215 CallLoweringInfo.reset(p: new MipsCallLowering(*getTargetLowering()));
216 Legalizer.reset(p: new MipsLegalizerInfo(*this));
217
218 auto *RBI = new MipsRegisterBankInfo(*getRegisterInfo());
219 RegBankInfo.reset(p: RBI);
220 InstSelector.reset(p: createMipsInstructionSelector(TM, *this, *RBI));
221}
222
223bool MipsSubtarget::isPositionIndependent() const {
224 return TM.isPositionIndependent();
225}
226
227/// This overrides the PostRAScheduler bit in the SchedModel for any CPU.
228bool MipsSubtarget::enablePostRAScheduler() const { return true; }
229
230void MipsSubtarget::getCriticalPathRCs(RegClassVector &CriticalPathRCs) const {
231 CriticalPathRCs.clear();
232 CriticalPathRCs.push_back(Elt: isGP64bit() ? &Mips::GPR64RegClass
233 : &Mips::GPR32RegClass);
234}
235
236CodeGenOptLevel MipsSubtarget::getOptLevelToEnablePostRAScheduler() const {
237 return CodeGenOptLevel::Aggressive;
238}
239
240MipsSubtarget &
241MipsSubtarget::initializeSubtargetDependencies(StringRef CPU, StringRef FS,
242 const TargetMachine &TM) {
243 StringRef CPUName = MIPS_MC::selectMipsCPU(TT: TM.getTargetTriple(), CPU);
244
245 // Parse features string.
246 ParseSubtargetFeatures(CPU: CPUName, /*TuneCPU*/ CPUName, FS);
247 // Initialize scheduling itinerary for the specified CPU.
248 InstrItins = getInstrItineraryForCPU(CPU: CPUName);
249
250 if (InMips16Mode && !IsSoftFloat)
251 InMips16HardFloat = true;
252
253 if (StackAlignOverride)
254 stackAlignment = *StackAlignOverride;
255 else if (isABI_N32() || isABI_N64())
256 stackAlignment = Align(16);
257 else {
258 assert(isABI_O32() && "Unknown ABI for stack alignment!");
259 stackAlignment = Align(8);
260 }
261
262 if ((isABI_N32() || isABI_N64()) && !isGP64bit())
263 report_fatal_error(reason: "64-bit code requested on a subtarget that doesn't "
264 "support it!");
265
266 return *this;
267}
268
269bool MipsSubtarget::useConstantIslands() {
270 LLVM_DEBUG(dbgs() << "use constant islands " << Mips16ConstantIslands
271 << "\n");
272 return Mips16ConstantIslands;
273}
274
275Reloc::Model MipsSubtarget::getRelocationModel() const {
276 return TM.getRelocationModel();
277}
278
279bool MipsSubtarget::isABI_N64() const { return getABI().IsN64(); }
280bool MipsSubtarget::isABI_N32() const { return getABI().IsN32(); }
281bool MipsSubtarget::isABI_O32() const { return getABI().IsO32(); }
282const MipsABIInfo &MipsSubtarget::getABI() const { return TM.getABI(); }
283
284const CallLowering *MipsSubtarget::getCallLowering() const {
285 return CallLoweringInfo.get();
286}
287
288const LegalizerInfo *MipsSubtarget::getLegalizerInfo() const {
289 return Legalizer.get();
290}
291
292const RegisterBankInfo *MipsSubtarget::getRegBankInfo() const {
293 return RegBankInfo.get();
294}
295
296InstructionSelector *MipsSubtarget::getInstructionSelector() const {
297 return InstSelector.get();
298}
299