1 //===- MipsLegalizerInfo.cpp ------------------------------------*- C++ -*-===//
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 /// \file
9 /// This file implements the targeting of the Machinelegalizer class for Mips.
10 /// \todo This should be generated by TableGen.
11 //===----------------------------------------------------------------------===//
12 
13 #include "MipsLegalizerInfo.h"
14 #include "MipsTargetMachine.h"
15 #include "llvm/CodeGen/GlobalISel/LegalizerHelper.h"
16 #include "llvm/IR/IntrinsicsMips.h"
17 
18 using namespace llvm;
19 
20 struct TypesAndMemOps {
21   LLT ValTy;
22   LLT PtrTy;
23   unsigned MemSize;
24   bool MustBeNaturallyAligned;
25 };
26 
27 static bool
28 CheckTy0Ty1MemSizeAlign(const LegalityQuery &Query,
29                         std::initializer_list<TypesAndMemOps> SupportedValues) {
30   for (auto &Val : SupportedValues) {
31     if (Val.ValTy != Query.Types[0])
32       continue;
33     if (Val.PtrTy != Query.Types[1])
34       continue;
35     if (Val.MemSize != Query.MMODescrs[0].SizeInBits)
36       continue;
37     if (Val.MustBeNaturallyAligned &&
38         Query.MMODescrs[0].SizeInBits % Query.MMODescrs[0].AlignInBits != 0)
39       continue;
40     return true;
41   }
42   return false;
43 }
44 
45 static bool CheckTyN(unsigned N, const LegalityQuery &Query,
46                      std::initializer_list<LLT> SupportedValues) {
47   for (auto &Val : SupportedValues)
48     if (Val == Query.Types[N])
49       return true;
50   return false;
51 }
52 
53 MipsLegalizerInfo::MipsLegalizerInfo(const MipsSubtarget &ST) {
54   using namespace TargetOpcode;
55 
56   const LLT s1 = LLT::scalar(1);
57   const LLT s32 = LLT::scalar(32);
58   const LLT s64 = LLT::scalar(64);
59   const LLT v16s8 = LLT::vector(16, 8);
60   const LLT v8s16 = LLT::vector(8, 16);
61   const LLT v4s32 = LLT::vector(4, 32);
62   const LLT v2s64 = LLT::vector(2, 64);
63   const LLT p0 = LLT::pointer(0, 32);
64 
65   getActionDefinitionsBuilder({G_ADD, G_SUB, G_MUL})
66       .legalIf([=, &ST](const LegalityQuery &Query) {
67         if (CheckTyN(0, Query, {s32}))
68           return true;
69         if (ST.hasMSA() && CheckTyN(0, Query, {v16s8, v8s16, v4s32, v2s64}))
70           return true;
71         return false;
72       })
73       .clampScalar(0, s32, s32);
74 
75   getActionDefinitionsBuilder({G_UADDO, G_UADDE, G_USUBO, G_USUBE, G_UMULO})
76       .lowerFor({{s32, s1}});
77 
78   getActionDefinitionsBuilder(G_UMULH)
79       .legalFor({s32})
80       .maxScalar(0, s32);
81 
82   getActionDefinitionsBuilder({G_LOAD, G_STORE})
83       .legalIf([=, &ST](const LegalityQuery &Query) {
84         if (CheckTy0Ty1MemSizeAlign(Query, {{s32, p0, 8, ST.hasMips32r6()},
85                                             {s32, p0, 16, ST.hasMips32r6()},
86                                             {s32, p0, 32, ST.hasMips32r6()},
87                                             {p0, p0, 32, ST.hasMips32r6()},
88                                             {s64, p0, 64, ST.hasMips32r6()}}))
89           return true;
90         if (ST.hasMSA() &&
91             CheckTy0Ty1MemSizeAlign(Query, {{v16s8, p0, 128, false},
92                                             {v8s16, p0, 128, false},
93                                             {v4s32, p0, 128, false},
94                                             {v2s64, p0, 128, false}}))
95           return true;
96         return false;
97       })
98       .minScalar(0, s32);
99 
100   getActionDefinitionsBuilder(G_IMPLICIT_DEF)
101       .legalFor({s32, s64});
102 
103   getActionDefinitionsBuilder(G_UNMERGE_VALUES)
104      .legalFor({{s32, s64}});
105 
106   getActionDefinitionsBuilder(G_MERGE_VALUES)
107      .legalFor({{s64, s32}});
108 
109   getActionDefinitionsBuilder({G_ZEXTLOAD, G_SEXTLOAD})
110       .legalForTypesWithMemDesc({{s32, p0, 8, 8},
111                                  {s32, p0, 16, 8}})
112       .clampScalar(0, s32, s32);
113 
114   getActionDefinitionsBuilder({G_ZEXT, G_SEXT})
115       .legalIf([](const LegalityQuery &Query) { return false; })
116       .maxScalar(0, s32);
117 
118   getActionDefinitionsBuilder(G_TRUNC)
119       .legalIf([](const LegalityQuery &Query) { return false; })
120       .maxScalar(1, s32);
121 
122   getActionDefinitionsBuilder(G_SELECT)
123       .legalForCartesianProduct({p0, s32, s64}, {s32})
124       .minScalar(0, s32)
125       .minScalar(1, s32);
126 
127   getActionDefinitionsBuilder(G_BRCOND)
128       .legalFor({s32})
129       .minScalar(0, s32);
130 
131   getActionDefinitionsBuilder(G_BRJT)
132       .legalFor({{p0, s32}});
133 
134   getActionDefinitionsBuilder(G_BRINDIRECT)
135       .legalFor({p0});
136 
137   getActionDefinitionsBuilder(G_PHI)
138       .legalFor({p0, s32, s64})
139       .minScalar(0, s32);
140 
141   getActionDefinitionsBuilder({G_AND, G_OR, G_XOR})
142       .legalFor({s32})
143       .clampScalar(0, s32, s32);
144 
145   getActionDefinitionsBuilder({G_SDIV, G_SREM, G_UDIV, G_UREM})
146       .legalIf([=, &ST](const LegalityQuery &Query) {
147         if (CheckTyN(0, Query, {s32}))
148           return true;
149         if (ST.hasMSA() && CheckTyN(0, Query, {v16s8, v8s16, v4s32, v2s64}))
150           return true;
151         return false;
152       })
153       .minScalar(0, s32)
154       .libcallFor({s64});
155 
156   getActionDefinitionsBuilder({G_SHL, G_ASHR, G_LSHR})
157       .legalFor({{s32, s32}})
158       .clampScalar(1, s32, s32)
159       .clampScalar(0, s32, s32);
160 
161   getActionDefinitionsBuilder(G_ICMP)
162       .legalForCartesianProduct({s32}, {s32, p0})
163       .clampScalar(1, s32, s32)
164       .minScalar(0, s32);
165 
166   getActionDefinitionsBuilder(G_CONSTANT)
167       .legalFor({s32})
168       .clampScalar(0, s32, s32);
169 
170   getActionDefinitionsBuilder({G_PTR_ADD, G_INTTOPTR})
171       .legalFor({{p0, s32}});
172 
173   getActionDefinitionsBuilder(G_PTRTOINT)
174       .legalFor({{s32, p0}});
175 
176   getActionDefinitionsBuilder(G_FRAME_INDEX)
177       .legalFor({p0});
178 
179   getActionDefinitionsBuilder({G_GLOBAL_VALUE, G_JUMP_TABLE})
180       .legalFor({p0});
181 
182   getActionDefinitionsBuilder(G_DYN_STACKALLOC)
183       .lowerFor({{p0, s32}});
184 
185   getActionDefinitionsBuilder(G_VASTART)
186      .legalFor({p0});
187 
188   getActionDefinitionsBuilder(G_BSWAP)
189       .legalIf([=, &ST](const LegalityQuery &Query) {
190         if (ST.hasMips32r2() && CheckTyN(0, Query, {s32}))
191           return true;
192         return false;
193       })
194       .lowerIf([=, &ST](const LegalityQuery &Query) {
195         if (!ST.hasMips32r2() && CheckTyN(0, Query, {s32}))
196           return true;
197         return false;
198       })
199       .maxScalar(0, s32);
200 
201   getActionDefinitionsBuilder(G_BITREVERSE)
202       .lowerFor({s32})
203       .maxScalar(0, s32);
204 
205   getActionDefinitionsBuilder(G_CTLZ)
206       .legalFor({{s32, s32}})
207       .maxScalar(1, s32);
208   getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
209       .lowerFor({{s32, s32}});
210 
211   getActionDefinitionsBuilder(G_CTTZ)
212       .lowerFor({{s32, s32}})
213       .maxScalar(1, s32);
214   getActionDefinitionsBuilder(G_CTTZ_ZERO_UNDEF)
215       .lowerFor({{s32, s32}, {s64, s64}});
216 
217   getActionDefinitionsBuilder(G_CTPOP)
218       .lowerFor({{s32, s32}})
219       .clampScalar(0, s32, s32)
220       .clampScalar(1, s32, s32);
221 
222   // FP instructions
223   getActionDefinitionsBuilder(G_FCONSTANT)
224       .legalFor({s32, s64});
225 
226   getActionDefinitionsBuilder({G_FADD, G_FSUB, G_FMUL, G_FDIV, G_FABS, G_FSQRT})
227       .legalIf([=, &ST](const LegalityQuery &Query) {
228         if (CheckTyN(0, Query, {s32, s64}))
229           return true;
230         if (ST.hasMSA() && CheckTyN(0, Query, {v16s8, v8s16, v4s32, v2s64}))
231           return true;
232         return false;
233       });
234 
235   getActionDefinitionsBuilder(G_FCMP)
236       .legalFor({{s32, s32}, {s32, s64}})
237       .minScalar(0, s32);
238 
239   getActionDefinitionsBuilder({G_FCEIL, G_FFLOOR})
240       .libcallFor({s32, s64});
241 
242   getActionDefinitionsBuilder(G_FPEXT)
243       .legalFor({{s64, s32}});
244 
245   getActionDefinitionsBuilder(G_FPTRUNC)
246       .legalFor({{s32, s64}});
247 
248   // FP to int conversion instructions
249   getActionDefinitionsBuilder(G_FPTOSI)
250       .legalForCartesianProduct({s32}, {s64, s32})
251       .libcallForCartesianProduct({s64}, {s64, s32})
252       .minScalar(0, s32);
253 
254   getActionDefinitionsBuilder(G_FPTOUI)
255       .libcallForCartesianProduct({s64}, {s64, s32})
256       .lowerForCartesianProduct({s32}, {s64, s32})
257       .minScalar(0, s32);
258 
259   // Int to FP conversion instructions
260   getActionDefinitionsBuilder(G_SITOFP)
261       .legalForCartesianProduct({s64, s32}, {s32})
262       .libcallForCartesianProduct({s64, s32}, {s64})
263       .minScalar(1, s32);
264 
265   getActionDefinitionsBuilder(G_UITOFP)
266       .libcallForCartesianProduct({s64, s32}, {s64})
267       .customForCartesianProduct({s64, s32}, {s32})
268       .minScalar(1, s32);
269 
270   getActionDefinitionsBuilder(G_SEXT_INREG).lower();
271 
272   computeTables();
273   verify(*ST.getInstrInfo());
274 }
275 
276 bool MipsLegalizerInfo::legalizeCustom(MachineInstr &MI,
277                                        MachineRegisterInfo &MRI,
278                                        MachineIRBuilder &MIRBuilder,
279                                        GISelChangeObserver &Observer) const {
280 
281   using namespace TargetOpcode;
282 
283   MIRBuilder.setInstr(MI);
284   const MipsSubtarget &STI =
285       static_cast<const MipsSubtarget &>(MIRBuilder.getMF().getSubtarget());
286   const LLT s32 = LLT::scalar(32);
287   const LLT s64 = LLT::scalar(64);
288 
289   switch (MI.getOpcode()) {
290   case G_UITOFP: {
291     Register Dst = MI.getOperand(0).getReg();
292     Register Src = MI.getOperand(1).getReg();
293     LLT DstTy = MRI.getType(Dst);
294     LLT SrcTy = MRI.getType(Src);
295 
296     if (SrcTy != s32)
297       return false;
298     if (DstTy != s32 && DstTy != s64)
299       return false;
300 
301     // Let 0xABCDEFGH be given unsigned in MI.getOperand(1). First let's convert
302     // unsigned to double. Mantissa has 52 bits so we use following trick:
303     // First make floating point bit mask 0x43300000ABCDEFGH.
304     // Mask represents 2^52 * 0x1.00000ABCDEFGH i.e. 0x100000ABCDEFGH.0 .
305     // Next, subtract  2^52 * 0x1.0000000000000 i.e. 0x10000000000000.0 from it.
306     // Done. Trunc double to float if needed.
307 
308     MachineInstrBuilder Bitcast = MIRBuilder.buildInstr(
309         STI.isFP64bit() ? Mips::BuildPairF64_64 : Mips::BuildPairF64, {s64},
310         {Src, MIRBuilder.buildConstant(s32, UINT32_C(0x43300000))});
311     Bitcast.constrainAllUses(MIRBuilder.getTII(), *STI.getRegisterInfo(),
312                              *STI.getRegBankInfo());
313 
314     MachineInstrBuilder TwoP52FP = MIRBuilder.buildFConstant(
315         s64, BitsToDouble(UINT64_C(0x4330000000000000)));
316 
317     if (DstTy == s64)
318       MIRBuilder.buildFSub(Dst, Bitcast, TwoP52FP);
319     else {
320       MachineInstrBuilder ResF64 = MIRBuilder.buildFSub(s64, Bitcast, TwoP52FP);
321       MIRBuilder.buildFPTrunc(Dst, ResF64);
322     }
323 
324     MI.eraseFromParent();
325     break;
326   }
327   default:
328     return false;
329   }
330 
331   return true;
332 }
333 
334 static bool SelectMSA3OpIntrinsic(MachineInstr &MI, unsigned Opcode,
335                                   MachineIRBuilder &MIRBuilder,
336                                   const MipsSubtarget &ST) {
337   assert(ST.hasMSA() && "MSA intrinsic not supported on target without MSA.");
338   if (!MIRBuilder.buildInstr(Opcode)
339            .add(MI.getOperand(0))
340            .add(MI.getOperand(2))
341            .add(MI.getOperand(3))
342            .constrainAllUses(MIRBuilder.getTII(), *ST.getRegisterInfo(),
343                              *ST.getRegBankInfo()))
344     return false;
345   MI.eraseFromParent();
346   return true;
347 }
348 
349 static bool MSA3OpIntrinsicToGeneric(MachineInstr &MI, unsigned Opcode,
350                                      MachineIRBuilder &MIRBuilder,
351                                      const MipsSubtarget &ST) {
352   assert(ST.hasMSA() && "MSA intrinsic not supported on target without MSA.");
353   MIRBuilder.buildInstr(Opcode)
354       .add(MI.getOperand(0))
355       .add(MI.getOperand(2))
356       .add(MI.getOperand(3));
357   MI.eraseFromParent();
358   return true;
359 }
360 
361 static bool MSA2OpIntrinsicToGeneric(MachineInstr &MI, unsigned Opcode,
362                                      MachineIRBuilder &MIRBuilder,
363                                      const MipsSubtarget &ST) {
364   assert(ST.hasMSA() && "MSA intrinsic not supported on target without MSA.");
365   MIRBuilder.buildInstr(Opcode)
366       .add(MI.getOperand(0))
367       .add(MI.getOperand(2));
368   MI.eraseFromParent();
369   return true;
370 }
371 
372 bool MipsLegalizerInfo::legalizeIntrinsic(MachineInstr &MI,
373                                           MachineIRBuilder &MIRBuilder,
374                                           GISelChangeObserver &Observer) const {
375   MachineRegisterInfo &MRI = *MIRBuilder.getMRI();
376   const MipsSubtarget &ST =
377       static_cast<const MipsSubtarget &>(MI.getMF()->getSubtarget());
378   const MipsInstrInfo &TII = *ST.getInstrInfo();
379   const MipsRegisterInfo &TRI = *ST.getRegisterInfo();
380   const RegisterBankInfo &RBI = *ST.getRegBankInfo();
381   MIRBuilder.setInstr(MI);
382 
383   switch (MI.getIntrinsicID()) {
384   case Intrinsic::memcpy:
385   case Intrinsic::memset:
386   case Intrinsic::memmove:
387     if (createMemLibcall(MIRBuilder, MRI, MI) ==
388         LegalizerHelper::UnableToLegalize)
389       return false;
390     MI.eraseFromParent();
391     return true;
392   case Intrinsic::trap: {
393     MachineInstr *Trap = MIRBuilder.buildInstr(Mips::TRAP);
394     MI.eraseFromParent();
395     return constrainSelectedInstRegOperands(*Trap, TII, TRI, RBI);
396   }
397   case Intrinsic::vacopy: {
398     MachinePointerInfo MPO;
399     auto Tmp = MIRBuilder.buildLoad(LLT::pointer(0, 32), MI.getOperand(2),
400                                     *MI.getMF()->getMachineMemOperand(
401                                         MPO, MachineMemOperand::MOLoad, 4, 4));
402     MIRBuilder.buildStore(Tmp, MI.getOperand(1),
403                           *MI.getMF()->getMachineMemOperand(
404                               MPO, MachineMemOperand::MOStore, 4, 4));
405     MI.eraseFromParent();
406     return true;
407   }
408   case Intrinsic::mips_addv_b:
409   case Intrinsic::mips_addv_h:
410   case Intrinsic::mips_addv_w:
411   case Intrinsic::mips_addv_d:
412     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_ADD, MIRBuilder, ST);
413   case Intrinsic::mips_addvi_b:
414     return SelectMSA3OpIntrinsic(MI, Mips::ADDVI_B, MIRBuilder, ST);
415   case Intrinsic::mips_addvi_h:
416     return SelectMSA3OpIntrinsic(MI, Mips::ADDVI_H, MIRBuilder, ST);
417   case Intrinsic::mips_addvi_w:
418     return SelectMSA3OpIntrinsic(MI, Mips::ADDVI_W, MIRBuilder, ST);
419   case Intrinsic::mips_addvi_d:
420     return SelectMSA3OpIntrinsic(MI, Mips::ADDVI_D, MIRBuilder, ST);
421   case Intrinsic::mips_subv_b:
422   case Intrinsic::mips_subv_h:
423   case Intrinsic::mips_subv_w:
424   case Intrinsic::mips_subv_d:
425     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_SUB, MIRBuilder, ST);
426   case Intrinsic::mips_subvi_b:
427     return SelectMSA3OpIntrinsic(MI, Mips::SUBVI_B, MIRBuilder, ST);
428   case Intrinsic::mips_subvi_h:
429     return SelectMSA3OpIntrinsic(MI, Mips::SUBVI_H, MIRBuilder, ST);
430   case Intrinsic::mips_subvi_w:
431     return SelectMSA3OpIntrinsic(MI, Mips::SUBVI_W, MIRBuilder, ST);
432   case Intrinsic::mips_subvi_d:
433     return SelectMSA3OpIntrinsic(MI, Mips::SUBVI_D, MIRBuilder, ST);
434   case Intrinsic::mips_mulv_b:
435   case Intrinsic::mips_mulv_h:
436   case Intrinsic::mips_mulv_w:
437   case Intrinsic::mips_mulv_d:
438     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_MUL, MIRBuilder, ST);
439   case Intrinsic::mips_div_s_b:
440   case Intrinsic::mips_div_s_h:
441   case Intrinsic::mips_div_s_w:
442   case Intrinsic::mips_div_s_d:
443     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_SDIV, MIRBuilder, ST);
444   case Intrinsic::mips_mod_s_b:
445   case Intrinsic::mips_mod_s_h:
446   case Intrinsic::mips_mod_s_w:
447   case Intrinsic::mips_mod_s_d:
448     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_SREM, MIRBuilder, ST);
449   case Intrinsic::mips_div_u_b:
450   case Intrinsic::mips_div_u_h:
451   case Intrinsic::mips_div_u_w:
452   case Intrinsic::mips_div_u_d:
453     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_UDIV, MIRBuilder, ST);
454   case Intrinsic::mips_mod_u_b:
455   case Intrinsic::mips_mod_u_h:
456   case Intrinsic::mips_mod_u_w:
457   case Intrinsic::mips_mod_u_d:
458     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_UREM, MIRBuilder, ST);
459   case Intrinsic::mips_fadd_w:
460   case Intrinsic::mips_fadd_d:
461     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_FADD, MIRBuilder, ST);
462   case Intrinsic::mips_fsub_w:
463   case Intrinsic::mips_fsub_d:
464     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_FSUB, MIRBuilder, ST);
465   case Intrinsic::mips_fmul_w:
466   case Intrinsic::mips_fmul_d:
467     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_FMUL, MIRBuilder, ST);
468   case Intrinsic::mips_fdiv_w:
469   case Intrinsic::mips_fdiv_d:
470     return MSA3OpIntrinsicToGeneric(MI, TargetOpcode::G_FDIV, MIRBuilder, ST);
471   case Intrinsic::mips_fmax_a_w:
472     return SelectMSA3OpIntrinsic(MI, Mips::FMAX_A_W, MIRBuilder, ST);
473   case Intrinsic::mips_fmax_a_d:
474     return SelectMSA3OpIntrinsic(MI, Mips::FMAX_A_D, MIRBuilder, ST);
475   case Intrinsic::mips_fsqrt_w:
476     return MSA2OpIntrinsicToGeneric(MI, TargetOpcode::G_FSQRT, MIRBuilder, ST);
477   case Intrinsic::mips_fsqrt_d:
478     return MSA2OpIntrinsicToGeneric(MI, TargetOpcode::G_FSQRT, MIRBuilder, ST);
479   default:
480     break;
481   }
482   return true;
483 }
484