1 | //===- llvm/CodeGen/GlobalISel/Utils.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 This file implements the utility functions used by the GlobalISel |
9 | /// pipeline. |
10 | //===----------------------------------------------------------------------===// |
11 | |
12 | #include "llvm/CodeGen/GlobalISel/Utils.h" |
13 | #include "llvm/ADT/APFloat.h" |
14 | #include "llvm/ADT/APInt.h" |
15 | #include "llvm/CodeGen/CodeGenCommonISel.h" |
16 | #include "llvm/CodeGen/GlobalISel/GISelChangeObserver.h" |
17 | #include "llvm/CodeGen/GlobalISel/GISelKnownBits.h" |
18 | #include "llvm/CodeGen/GlobalISel/GenericMachineInstrs.h" |
19 | #include "llvm/CodeGen/GlobalISel/LostDebugLocObserver.h" |
20 | #include "llvm/CodeGen/GlobalISel/MIPatternMatch.h" |
21 | #include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h" |
22 | #include "llvm/CodeGen/MachineInstr.h" |
23 | #include "llvm/CodeGen/MachineInstrBuilder.h" |
24 | #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h" |
25 | #include "llvm/CodeGen/MachineRegisterInfo.h" |
26 | #include "llvm/CodeGen/MachineSizeOpts.h" |
27 | #include "llvm/CodeGen/RegisterBankInfo.h" |
28 | #include "llvm/CodeGen/StackProtector.h" |
29 | #include "llvm/CodeGen/TargetInstrInfo.h" |
30 | #include "llvm/CodeGen/TargetLowering.h" |
31 | #include "llvm/CodeGen/TargetPassConfig.h" |
32 | #include "llvm/CodeGen/TargetRegisterInfo.h" |
33 | #include "llvm/IR/Constants.h" |
34 | #include "llvm/Target/TargetMachine.h" |
35 | #include "llvm/Transforms/Utils/SizeOpts.h" |
36 | #include <numeric> |
37 | #include <optional> |
38 | |
39 | #define DEBUG_TYPE "globalisel-utils" |
40 | |
41 | using namespace llvm; |
42 | using namespace MIPatternMatch; |
43 | |
44 | Register llvm::constrainRegToClass(MachineRegisterInfo &MRI, |
45 | const TargetInstrInfo &TII, |
46 | const RegisterBankInfo &RBI, Register Reg, |
47 | const TargetRegisterClass &RegClass) { |
48 | if (!RBI.constrainGenericRegister(Reg, RC: RegClass, MRI)) |
49 | return MRI.createVirtualRegister(RegClass: &RegClass); |
50 | |
51 | return Reg; |
52 | } |
53 | |
54 | Register llvm::constrainOperandRegClass( |
55 | const MachineFunction &MF, const TargetRegisterInfo &TRI, |
56 | MachineRegisterInfo &MRI, const TargetInstrInfo &TII, |
57 | const RegisterBankInfo &RBI, MachineInstr &InsertPt, |
58 | const TargetRegisterClass &RegClass, MachineOperand &RegMO) { |
59 | Register Reg = RegMO.getReg(); |
60 | // Assume physical registers are properly constrained. |
61 | assert(Reg.isVirtual() && "PhysReg not implemented" ); |
62 | |
63 | // Save the old register class to check whether |
64 | // the change notifications will be required. |
65 | // TODO: A better approach would be to pass |
66 | // the observers to constrainRegToClass(). |
67 | auto *OldRegClass = MRI.getRegClassOrNull(Reg); |
68 | Register ConstrainedReg = constrainRegToClass(MRI, TII, RBI, Reg, RegClass); |
69 | // If we created a new virtual register because the class is not compatible |
70 | // then create a copy between the new and the old register. |
71 | if (ConstrainedReg != Reg) { |
72 | MachineBasicBlock::iterator InsertIt(&InsertPt); |
73 | MachineBasicBlock &MBB = *InsertPt.getParent(); |
74 | // FIXME: The copy needs to have the classes constrained for its operands. |
75 | // Use operand's regbank to get the class for old register (Reg). |
76 | if (RegMO.isUse()) { |
77 | BuildMI(BB&: MBB, I: InsertIt, MIMD: InsertPt.getDebugLoc(), |
78 | MCID: TII.get(Opcode: TargetOpcode::COPY), DestReg: ConstrainedReg) |
79 | .addReg(RegNo: Reg); |
80 | } else { |
81 | assert(RegMO.isDef() && "Must be a definition" ); |
82 | BuildMI(BB&: MBB, I: std::next(x: InsertIt), MIMD: InsertPt.getDebugLoc(), |
83 | MCID: TII.get(Opcode: TargetOpcode::COPY), DestReg: Reg) |
84 | .addReg(RegNo: ConstrainedReg); |
85 | } |
86 | if (GISelChangeObserver *Observer = MF.getObserver()) { |
87 | Observer->changingInstr(MI&: *RegMO.getParent()); |
88 | } |
89 | RegMO.setReg(ConstrainedReg); |
90 | if (GISelChangeObserver *Observer = MF.getObserver()) { |
91 | Observer->changedInstr(MI&: *RegMO.getParent()); |
92 | } |
93 | } else if (OldRegClass != MRI.getRegClassOrNull(Reg)) { |
94 | if (GISelChangeObserver *Observer = MF.getObserver()) { |
95 | if (!RegMO.isDef()) { |
96 | MachineInstr *RegDef = MRI.getVRegDef(Reg); |
97 | Observer->changedInstr(MI&: *RegDef); |
98 | } |
99 | Observer->changingAllUsesOfReg(MRI, Reg); |
100 | Observer->finishedChangingAllUsesOfReg(); |
101 | } |
102 | } |
103 | return ConstrainedReg; |
104 | } |
105 | |
106 | Register llvm::constrainOperandRegClass( |
107 | const MachineFunction &MF, const TargetRegisterInfo &TRI, |
108 | MachineRegisterInfo &MRI, const TargetInstrInfo &TII, |
109 | const RegisterBankInfo &RBI, MachineInstr &InsertPt, const MCInstrDesc &II, |
110 | MachineOperand &RegMO, unsigned OpIdx) { |
111 | Register Reg = RegMO.getReg(); |
112 | // Assume physical registers are properly constrained. |
113 | assert(Reg.isVirtual() && "PhysReg not implemented" ); |
114 | |
115 | const TargetRegisterClass *OpRC = TII.getRegClass(MCID: II, OpNum: OpIdx, TRI: &TRI, MF); |
116 | // Some of the target independent instructions, like COPY, may not impose any |
117 | // register class constraints on some of their operands: If it's a use, we can |
118 | // skip constraining as the instruction defining the register would constrain |
119 | // it. |
120 | |
121 | if (OpRC) { |
122 | // Obtain the RC from incoming regbank if it is a proper sub-class. Operands |
123 | // can have multiple regbanks for a superclass that combine different |
124 | // register types (E.g., AMDGPU's VGPR and AGPR). The regbank ambiguity |
125 | // resolved by targets during regbankselect should not be overridden. |
126 | if (const auto *SubRC = TRI.getCommonSubClass( |
127 | A: OpRC, B: TRI.getConstrainedRegClassForOperand(MO: RegMO, MRI))) |
128 | OpRC = SubRC; |
129 | |
130 | OpRC = TRI.getAllocatableClass(RC: OpRC); |
131 | } |
132 | |
133 | if (!OpRC) { |
134 | assert((!isTargetSpecificOpcode(II.getOpcode()) || RegMO.isUse()) && |
135 | "Register class constraint is required unless either the " |
136 | "instruction is target independent or the operand is a use" ); |
137 | // FIXME: Just bailing out like this here could be not enough, unless we |
138 | // expect the users of this function to do the right thing for PHIs and |
139 | // COPY: |
140 | // v1 = COPY v0 |
141 | // v2 = COPY v1 |
142 | // v1 here may end up not being constrained at all. Please notice that to |
143 | // reproduce the issue we likely need a destination pattern of a selection |
144 | // rule producing such extra copies, not just an input GMIR with them as |
145 | // every existing target using selectImpl handles copies before calling it |
146 | // and they never reach this function. |
147 | return Reg; |
148 | } |
149 | return constrainOperandRegClass(MF, TRI, MRI, TII, RBI, InsertPt, RegClass: *OpRC, |
150 | RegMO); |
151 | } |
152 | |
153 | bool llvm::constrainSelectedInstRegOperands(MachineInstr &I, |
154 | const TargetInstrInfo &TII, |
155 | const TargetRegisterInfo &TRI, |
156 | const RegisterBankInfo &RBI) { |
157 | assert(!isPreISelGenericOpcode(I.getOpcode()) && |
158 | "A selected instruction is expected" ); |
159 | MachineBasicBlock &MBB = *I.getParent(); |
160 | MachineFunction &MF = *MBB.getParent(); |
161 | MachineRegisterInfo &MRI = MF.getRegInfo(); |
162 | |
163 | for (unsigned OpI = 0, OpE = I.getNumExplicitOperands(); OpI != OpE; ++OpI) { |
164 | MachineOperand &MO = I.getOperand(i: OpI); |
165 | |
166 | // There's nothing to be done on non-register operands. |
167 | if (!MO.isReg()) |
168 | continue; |
169 | |
170 | LLVM_DEBUG(dbgs() << "Converting operand: " << MO << '\n'); |
171 | assert(MO.isReg() && "Unsupported non-reg operand" ); |
172 | |
173 | Register Reg = MO.getReg(); |
174 | // Physical registers don't need to be constrained. |
175 | if (Reg.isPhysical()) |
176 | continue; |
177 | |
178 | // Register operands with a value of 0 (e.g. predicate operands) don't need |
179 | // to be constrained. |
180 | if (Reg == 0) |
181 | continue; |
182 | |
183 | // If the operand is a vreg, we should constrain its regclass, and only |
184 | // insert COPYs if that's impossible. |
185 | // constrainOperandRegClass does that for us. |
186 | constrainOperandRegClass(MF, TRI, MRI, TII, RBI, InsertPt&: I, II: I.getDesc(), RegMO&: MO, OpIdx: OpI); |
187 | |
188 | // Tie uses to defs as indicated in MCInstrDesc if this hasn't already been |
189 | // done. |
190 | if (MO.isUse()) { |
191 | int DefIdx = I.getDesc().getOperandConstraint(OpNum: OpI, Constraint: MCOI::TIED_TO); |
192 | if (DefIdx != -1 && !I.isRegTiedToUseOperand(DefOpIdx: DefIdx)) |
193 | I.tieOperands(DefIdx, UseIdx: OpI); |
194 | } |
195 | } |
196 | return true; |
197 | } |
198 | |
199 | bool llvm::canReplaceReg(Register DstReg, Register SrcReg, |
200 | MachineRegisterInfo &MRI) { |
201 | // Give up if either DstReg or SrcReg is a physical register. |
202 | if (DstReg.isPhysical() || SrcReg.isPhysical()) |
203 | return false; |
204 | // Give up if the types don't match. |
205 | if (MRI.getType(Reg: DstReg) != MRI.getType(Reg: SrcReg)) |
206 | return false; |
207 | // Replace if either DstReg has no constraints or the register |
208 | // constraints match. |
209 | const auto &DstRBC = MRI.getRegClassOrRegBank(Reg: DstReg); |
210 | if (!DstRBC || DstRBC == MRI.getRegClassOrRegBank(Reg: SrcReg)) |
211 | return true; |
212 | |
213 | // Otherwise match if the Src is already a regclass that is covered by the Dst |
214 | // RegBank. |
215 | return DstRBC.is<const RegisterBank *>() && MRI.getRegClassOrNull(Reg: SrcReg) && |
216 | DstRBC.get<const RegisterBank *>()->covers( |
217 | RC: *MRI.getRegClassOrNull(Reg: SrcReg)); |
218 | } |
219 | |
220 | bool llvm::isTriviallyDead(const MachineInstr &MI, |
221 | const MachineRegisterInfo &MRI) { |
222 | // FIXME: This logical is mostly duplicated with |
223 | // DeadMachineInstructionElim::isDead. Why is LOCAL_ESCAPE not considered in |
224 | // MachineInstr::isLabel? |
225 | |
226 | // Don't delete frame allocation labels. |
227 | if (MI.getOpcode() == TargetOpcode::LOCAL_ESCAPE) |
228 | return false; |
229 | // LIFETIME markers should be preserved even if they seem dead. |
230 | if (MI.getOpcode() == TargetOpcode::LIFETIME_START || |
231 | MI.getOpcode() == TargetOpcode::LIFETIME_END) |
232 | return false; |
233 | |
234 | // If we can move an instruction, we can remove it. Otherwise, it has |
235 | // a side-effect of some sort. |
236 | bool SawStore = false; |
237 | if (!MI.isSafeToMove(/*AA=*/nullptr, SawStore) && !MI.isPHI()) |
238 | return false; |
239 | |
240 | // Instructions without side-effects are dead iff they only define dead vregs. |
241 | for (const auto &MO : MI.all_defs()) { |
242 | Register Reg = MO.getReg(); |
243 | if (Reg.isPhysical() || !MRI.use_nodbg_empty(RegNo: Reg)) |
244 | return false; |
245 | } |
246 | return true; |
247 | } |
248 | |
249 | static void (DiagnosticSeverity Severity, |
250 | MachineFunction &MF, |
251 | const TargetPassConfig &TPC, |
252 | MachineOptimizationRemarkEmitter &MORE, |
253 | MachineOptimizationRemarkMissed &R) { |
254 | bool IsFatal = Severity == DS_Error && |
255 | TPC.isGlobalISelAbortEnabled(); |
256 | // Print the function name explicitly if we don't have a debug location (which |
257 | // makes the diagnostic less useful) or if we're going to emit a raw error. |
258 | if (!R.getLocation().isValid() || IsFatal) |
259 | R << (" (in function: " + MF.getName() + ")" ).str(); |
260 | |
261 | if (IsFatal) |
262 | report_fatal_error(reason: Twine(R.getMsg())); |
263 | else |
264 | MORE.emit(OptDiag&: R); |
265 | } |
266 | |
267 | void llvm::(MachineFunction &MF, const TargetPassConfig &TPC, |
268 | MachineOptimizationRemarkEmitter &MORE, |
269 | MachineOptimizationRemarkMissed &R) { |
270 | reportGISelDiagnostic(Severity: DS_Warning, MF, TPC, MORE, R); |
271 | } |
272 | |
273 | void llvm::(MachineFunction &MF, const TargetPassConfig &TPC, |
274 | MachineOptimizationRemarkEmitter &MORE, |
275 | MachineOptimizationRemarkMissed &R) { |
276 | MF.getProperties().set(MachineFunctionProperties::Property::FailedISel); |
277 | reportGISelDiagnostic(Severity: DS_Error, MF, TPC, MORE, R); |
278 | } |
279 | |
280 | void llvm::(MachineFunction &MF, const TargetPassConfig &TPC, |
281 | MachineOptimizationRemarkEmitter &MORE, |
282 | const char *PassName, StringRef Msg, |
283 | const MachineInstr &MI) { |
284 | MachineOptimizationRemarkMissed R(PassName, "GISelFailure: " , |
285 | MI.getDebugLoc(), MI.getParent()); |
286 | R << Msg; |
287 | // Printing MI is expensive; only do it if expensive remarks are enabled. |
288 | if (TPC.isGlobalISelAbortEnabled() || MORE.allowExtraAnalysis(PassName)) |
289 | R << ": " << ore::MNV("Inst" , MI); |
290 | reportGISelFailure(MF, TPC, MORE, R); |
291 | } |
292 | |
293 | std::optional<APInt> llvm::getIConstantVRegVal(Register VReg, |
294 | const MachineRegisterInfo &MRI) { |
295 | std::optional<ValueAndVReg> ValAndVReg = getIConstantVRegValWithLookThrough( |
296 | VReg, MRI, /*LookThroughInstrs*/ false); |
297 | assert((!ValAndVReg || ValAndVReg->VReg == VReg) && |
298 | "Value found while looking through instrs" ); |
299 | if (!ValAndVReg) |
300 | return std::nullopt; |
301 | return ValAndVReg->Value; |
302 | } |
303 | |
304 | std::optional<int64_t> |
305 | llvm::getIConstantVRegSExtVal(Register VReg, const MachineRegisterInfo &MRI) { |
306 | std::optional<APInt> Val = getIConstantVRegVal(VReg, MRI); |
307 | if (Val && Val->getBitWidth() <= 64) |
308 | return Val->getSExtValue(); |
309 | return std::nullopt; |
310 | } |
311 | |
312 | namespace { |
313 | |
314 | typedef std::function<bool(const MachineInstr *)> IsOpcodeFn; |
315 | typedef std::function<std::optional<APInt>(const MachineInstr *MI)> GetAPCstFn; |
316 | |
317 | std::optional<ValueAndVReg> getConstantVRegValWithLookThrough( |
318 | Register VReg, const MachineRegisterInfo &MRI, IsOpcodeFn IsConstantOpcode, |
319 | GetAPCstFn getAPCstValue, bool LookThroughInstrs = true, |
320 | bool LookThroughAnyExt = false) { |
321 | SmallVector<std::pair<unsigned, unsigned>, 4> SeenOpcodes; |
322 | MachineInstr *MI; |
323 | |
324 | while ((MI = MRI.getVRegDef(Reg: VReg)) && !IsConstantOpcode(MI) && |
325 | LookThroughInstrs) { |
326 | switch (MI->getOpcode()) { |
327 | case TargetOpcode::G_ANYEXT: |
328 | if (!LookThroughAnyExt) |
329 | return std::nullopt; |
330 | [[fallthrough]]; |
331 | case TargetOpcode::G_TRUNC: |
332 | case TargetOpcode::G_SEXT: |
333 | case TargetOpcode::G_ZEXT: |
334 | SeenOpcodes.push_back(Elt: std::make_pair( |
335 | x: MI->getOpcode(), |
336 | y: MRI.getType(Reg: MI->getOperand(i: 0).getReg()).getSizeInBits())); |
337 | VReg = MI->getOperand(i: 1).getReg(); |
338 | break; |
339 | case TargetOpcode::COPY: |
340 | VReg = MI->getOperand(i: 1).getReg(); |
341 | if (VReg.isPhysical()) |
342 | return std::nullopt; |
343 | break; |
344 | case TargetOpcode::G_INTTOPTR: |
345 | VReg = MI->getOperand(i: 1).getReg(); |
346 | break; |
347 | default: |
348 | return std::nullopt; |
349 | } |
350 | } |
351 | if (!MI || !IsConstantOpcode(MI)) |
352 | return std::nullopt; |
353 | |
354 | std::optional<APInt> MaybeVal = getAPCstValue(MI); |
355 | if (!MaybeVal) |
356 | return std::nullopt; |
357 | APInt &Val = *MaybeVal; |
358 | while (!SeenOpcodes.empty()) { |
359 | std::pair<unsigned, unsigned> OpcodeAndSize = SeenOpcodes.pop_back_val(); |
360 | switch (OpcodeAndSize.first) { |
361 | case TargetOpcode::G_TRUNC: |
362 | Val = Val.trunc(width: OpcodeAndSize.second); |
363 | break; |
364 | case TargetOpcode::G_ANYEXT: |
365 | case TargetOpcode::G_SEXT: |
366 | Val = Val.sext(width: OpcodeAndSize.second); |
367 | break; |
368 | case TargetOpcode::G_ZEXT: |
369 | Val = Val.zext(width: OpcodeAndSize.second); |
370 | break; |
371 | } |
372 | } |
373 | |
374 | return ValueAndVReg{.Value: Val, .VReg: VReg}; |
375 | } |
376 | |
377 | bool isIConstant(const MachineInstr *MI) { |
378 | if (!MI) |
379 | return false; |
380 | return MI->getOpcode() == TargetOpcode::G_CONSTANT; |
381 | } |
382 | |
383 | bool isFConstant(const MachineInstr *MI) { |
384 | if (!MI) |
385 | return false; |
386 | return MI->getOpcode() == TargetOpcode::G_FCONSTANT; |
387 | } |
388 | |
389 | bool isAnyConstant(const MachineInstr *MI) { |
390 | if (!MI) |
391 | return false; |
392 | unsigned Opc = MI->getOpcode(); |
393 | return Opc == TargetOpcode::G_CONSTANT || Opc == TargetOpcode::G_FCONSTANT; |
394 | } |
395 | |
396 | std::optional<APInt> getCImmAsAPInt(const MachineInstr *MI) { |
397 | const MachineOperand &CstVal = MI->getOperand(i: 1); |
398 | if (CstVal.isCImm()) |
399 | return CstVal.getCImm()->getValue(); |
400 | return std::nullopt; |
401 | } |
402 | |
403 | std::optional<APInt> getCImmOrFPImmAsAPInt(const MachineInstr *MI) { |
404 | const MachineOperand &CstVal = MI->getOperand(i: 1); |
405 | if (CstVal.isCImm()) |
406 | return CstVal.getCImm()->getValue(); |
407 | if (CstVal.isFPImm()) |
408 | return CstVal.getFPImm()->getValueAPF().bitcastToAPInt(); |
409 | return std::nullopt; |
410 | } |
411 | |
412 | } // end anonymous namespace |
413 | |
414 | std::optional<ValueAndVReg> llvm::getIConstantVRegValWithLookThrough( |
415 | Register VReg, const MachineRegisterInfo &MRI, bool LookThroughInstrs) { |
416 | return getConstantVRegValWithLookThrough(VReg, MRI, IsConstantOpcode: isIConstant, |
417 | getAPCstValue: getCImmAsAPInt, LookThroughInstrs); |
418 | } |
419 | |
420 | std::optional<ValueAndVReg> llvm::getAnyConstantVRegValWithLookThrough( |
421 | Register VReg, const MachineRegisterInfo &MRI, bool LookThroughInstrs, |
422 | bool LookThroughAnyExt) { |
423 | return getConstantVRegValWithLookThrough( |
424 | VReg, MRI, IsConstantOpcode: isAnyConstant, getAPCstValue: getCImmOrFPImmAsAPInt, LookThroughInstrs, |
425 | LookThroughAnyExt); |
426 | } |
427 | |
428 | std::optional<FPValueAndVReg> llvm::getFConstantVRegValWithLookThrough( |
429 | Register VReg, const MachineRegisterInfo &MRI, bool LookThroughInstrs) { |
430 | auto Reg = getConstantVRegValWithLookThrough( |
431 | VReg, MRI, IsConstantOpcode: isFConstant, getAPCstValue: getCImmOrFPImmAsAPInt, LookThroughInstrs); |
432 | if (!Reg) |
433 | return std::nullopt; |
434 | return FPValueAndVReg{.Value: getConstantFPVRegVal(VReg: Reg->VReg, MRI)->getValueAPF(), |
435 | .VReg: Reg->VReg}; |
436 | } |
437 | |
438 | const ConstantFP * |
439 | llvm::getConstantFPVRegVal(Register VReg, const MachineRegisterInfo &MRI) { |
440 | MachineInstr *MI = MRI.getVRegDef(Reg: VReg); |
441 | if (TargetOpcode::G_FCONSTANT != MI->getOpcode()) |
442 | return nullptr; |
443 | return MI->getOperand(i: 1).getFPImm(); |
444 | } |
445 | |
446 | std::optional<DefinitionAndSourceRegister> |
447 | llvm::getDefSrcRegIgnoringCopies(Register Reg, const MachineRegisterInfo &MRI) { |
448 | Register DefSrcReg = Reg; |
449 | auto *DefMI = MRI.getVRegDef(Reg); |
450 | auto DstTy = MRI.getType(Reg: DefMI->getOperand(i: 0).getReg()); |
451 | if (!DstTy.isValid()) |
452 | return std::nullopt; |
453 | unsigned Opc = DefMI->getOpcode(); |
454 | while (Opc == TargetOpcode::COPY || isPreISelGenericOptimizationHint(Opcode: Opc)) { |
455 | Register SrcReg = DefMI->getOperand(i: 1).getReg(); |
456 | auto SrcTy = MRI.getType(Reg: SrcReg); |
457 | if (!SrcTy.isValid()) |
458 | break; |
459 | DefMI = MRI.getVRegDef(Reg: SrcReg); |
460 | DefSrcReg = SrcReg; |
461 | Opc = DefMI->getOpcode(); |
462 | } |
463 | return DefinitionAndSourceRegister{.MI: DefMI, .Reg: DefSrcReg}; |
464 | } |
465 | |
466 | MachineInstr *llvm::getDefIgnoringCopies(Register Reg, |
467 | const MachineRegisterInfo &MRI) { |
468 | std::optional<DefinitionAndSourceRegister> DefSrcReg = |
469 | getDefSrcRegIgnoringCopies(Reg, MRI); |
470 | return DefSrcReg ? DefSrcReg->MI : nullptr; |
471 | } |
472 | |
473 | Register llvm::getSrcRegIgnoringCopies(Register Reg, |
474 | const MachineRegisterInfo &MRI) { |
475 | std::optional<DefinitionAndSourceRegister> DefSrcReg = |
476 | getDefSrcRegIgnoringCopies(Reg, MRI); |
477 | return DefSrcReg ? DefSrcReg->Reg : Register(); |
478 | } |
479 | |
480 | void llvm::(Register Reg, LLT Ty, int NumParts, |
481 | SmallVectorImpl<Register> &VRegs, |
482 | MachineIRBuilder &MIRBuilder, |
483 | MachineRegisterInfo &MRI) { |
484 | for (int i = 0; i < NumParts; ++i) |
485 | VRegs.push_back(Elt: MRI.createGenericVirtualRegister(Ty)); |
486 | MIRBuilder.buildUnmerge(Res: VRegs, Op: Reg); |
487 | } |
488 | |
489 | bool llvm::(Register Reg, LLT RegTy, LLT MainTy, LLT &LeftoverTy, |
490 | SmallVectorImpl<Register> &VRegs, |
491 | SmallVectorImpl<Register> &LeftoverRegs, |
492 | MachineIRBuilder &MIRBuilder, |
493 | MachineRegisterInfo &MRI) { |
494 | assert(!LeftoverTy.isValid() && "this is an out argument" ); |
495 | |
496 | unsigned RegSize = RegTy.getSizeInBits(); |
497 | unsigned MainSize = MainTy.getSizeInBits(); |
498 | unsigned NumParts = RegSize / MainSize; |
499 | unsigned LeftoverSize = RegSize - NumParts * MainSize; |
500 | |
501 | // Use an unmerge when possible. |
502 | if (LeftoverSize == 0) { |
503 | for (unsigned I = 0; I < NumParts; ++I) |
504 | VRegs.push_back(Elt: MRI.createGenericVirtualRegister(Ty: MainTy)); |
505 | MIRBuilder.buildUnmerge(Res: VRegs, Op: Reg); |
506 | return true; |
507 | } |
508 | |
509 | // Try to use unmerge for irregular vector split where possible |
510 | // For example when splitting a <6 x i32> into <4 x i32> with <2 x i32> |
511 | // leftover, it becomes: |
512 | // <2 x i32> %2, <2 x i32>%3, <2 x i32> %4 = G_UNMERGE_VALUE <6 x i32> %1 |
513 | // <4 x i32> %5 = G_CONCAT_VECTOR <2 x i32> %2, <2 x i32> %3 |
514 | if (RegTy.isVector() && MainTy.isVector()) { |
515 | unsigned RegNumElts = RegTy.getNumElements(); |
516 | unsigned MainNumElts = MainTy.getNumElements(); |
517 | unsigned LeftoverNumElts = RegNumElts % MainNumElts; |
518 | // If can unmerge to LeftoverTy, do it |
519 | if (MainNumElts % LeftoverNumElts == 0 && |
520 | RegNumElts % LeftoverNumElts == 0 && |
521 | RegTy.getScalarSizeInBits() == MainTy.getScalarSizeInBits() && |
522 | LeftoverNumElts > 1) { |
523 | LeftoverTy = |
524 | LLT::fixed_vector(NumElements: LeftoverNumElts, ScalarSizeInBits: RegTy.getScalarSizeInBits()); |
525 | |
526 | // Unmerge the SrcReg to LeftoverTy vectors |
527 | SmallVector<Register, 4> UnmergeValues; |
528 | extractParts(Reg, Ty: LeftoverTy, NumParts: RegNumElts / LeftoverNumElts, VRegs&: UnmergeValues, |
529 | MIRBuilder, MRI); |
530 | |
531 | // Find how many LeftoverTy makes one MainTy |
532 | unsigned LeftoverPerMain = MainNumElts / LeftoverNumElts; |
533 | unsigned NumOfLeftoverVal = |
534 | ((RegNumElts % MainNumElts) / LeftoverNumElts); |
535 | |
536 | // Create as many MainTy as possible using unmerged value |
537 | SmallVector<Register, 4> MergeValues; |
538 | for (unsigned I = 0; I < UnmergeValues.size() - NumOfLeftoverVal; I++) { |
539 | MergeValues.push_back(Elt: UnmergeValues[I]); |
540 | if (MergeValues.size() == LeftoverPerMain) { |
541 | VRegs.push_back( |
542 | Elt: MIRBuilder.buildMergeLikeInstr(Res: MainTy, Ops: MergeValues).getReg(Idx: 0)); |
543 | MergeValues.clear(); |
544 | } |
545 | } |
546 | // Populate LeftoverRegs with the leftovers |
547 | for (unsigned I = UnmergeValues.size() - NumOfLeftoverVal; |
548 | I < UnmergeValues.size(); I++) { |
549 | LeftoverRegs.push_back(Elt: UnmergeValues[I]); |
550 | } |
551 | return true; |
552 | } |
553 | } |
554 | // Perform irregular split. Leftover is last element of RegPieces. |
555 | if (MainTy.isVector()) { |
556 | SmallVector<Register, 8> RegPieces; |
557 | extractVectorParts(Reg, NumElts: MainTy.getNumElements(), VRegs&: RegPieces, MIRBuilder, |
558 | MRI); |
559 | for (unsigned i = 0; i < RegPieces.size() - 1; ++i) |
560 | VRegs.push_back(Elt: RegPieces[i]); |
561 | LeftoverRegs.push_back(Elt: RegPieces[RegPieces.size() - 1]); |
562 | LeftoverTy = MRI.getType(Reg: LeftoverRegs[0]); |
563 | return true; |
564 | } |
565 | |
566 | LeftoverTy = LLT::scalar(SizeInBits: LeftoverSize); |
567 | // For irregular sizes, extract the individual parts. |
568 | for (unsigned I = 0; I != NumParts; ++I) { |
569 | Register NewReg = MRI.createGenericVirtualRegister(Ty: MainTy); |
570 | VRegs.push_back(Elt: NewReg); |
571 | MIRBuilder.buildExtract(Res: NewReg, Src: Reg, Index: MainSize * I); |
572 | } |
573 | |
574 | for (unsigned Offset = MainSize * NumParts; Offset < RegSize; |
575 | Offset += LeftoverSize) { |
576 | Register NewReg = MRI.createGenericVirtualRegister(Ty: LeftoverTy); |
577 | LeftoverRegs.push_back(Elt: NewReg); |
578 | MIRBuilder.buildExtract(Res: NewReg, Src: Reg, Index: Offset); |
579 | } |
580 | |
581 | return true; |
582 | } |
583 | |
584 | void llvm::(Register Reg, unsigned NumElts, |
585 | SmallVectorImpl<Register> &VRegs, |
586 | MachineIRBuilder &MIRBuilder, |
587 | MachineRegisterInfo &MRI) { |
588 | LLT RegTy = MRI.getType(Reg); |
589 | assert(RegTy.isVector() && "Expected a vector type" ); |
590 | |
591 | LLT EltTy = RegTy.getElementType(); |
592 | LLT NarrowTy = (NumElts == 1) ? EltTy : LLT::fixed_vector(NumElements: NumElts, ScalarTy: EltTy); |
593 | unsigned RegNumElts = RegTy.getNumElements(); |
594 | unsigned LeftoverNumElts = RegNumElts % NumElts; |
595 | unsigned NumNarrowTyPieces = RegNumElts / NumElts; |
596 | |
597 | // Perfect split without leftover |
598 | if (LeftoverNumElts == 0) |
599 | return extractParts(Reg, Ty: NarrowTy, NumParts: NumNarrowTyPieces, VRegs, MIRBuilder, |
600 | MRI); |
601 | |
602 | // Irregular split. Provide direct access to all elements for artifact |
603 | // combiner using unmerge to elements. Then build vectors with NumElts |
604 | // elements. Remaining element(s) will be (used to build vector) Leftover. |
605 | SmallVector<Register, 8> Elts; |
606 | extractParts(Reg, Ty: EltTy, NumParts: RegNumElts, VRegs&: Elts, MIRBuilder, MRI); |
607 | |
608 | unsigned Offset = 0; |
609 | // Requested sub-vectors of NarrowTy. |
610 | for (unsigned i = 0; i < NumNarrowTyPieces; ++i, Offset += NumElts) { |
611 | ArrayRef<Register> Pieces(&Elts[Offset], NumElts); |
612 | VRegs.push_back(Elt: MIRBuilder.buildMergeLikeInstr(Res: NarrowTy, Ops: Pieces).getReg(Idx: 0)); |
613 | } |
614 | |
615 | // Leftover element(s). |
616 | if (LeftoverNumElts == 1) { |
617 | VRegs.push_back(Elt: Elts[Offset]); |
618 | } else { |
619 | LLT LeftoverTy = LLT::fixed_vector(NumElements: LeftoverNumElts, ScalarTy: EltTy); |
620 | ArrayRef<Register> Pieces(&Elts[Offset], LeftoverNumElts); |
621 | VRegs.push_back( |
622 | Elt: MIRBuilder.buildMergeLikeInstr(Res: LeftoverTy, Ops: Pieces).getReg(Idx: 0)); |
623 | } |
624 | } |
625 | |
626 | MachineInstr *llvm::getOpcodeDef(unsigned Opcode, Register Reg, |
627 | const MachineRegisterInfo &MRI) { |
628 | MachineInstr *DefMI = getDefIgnoringCopies(Reg, MRI); |
629 | return DefMI && DefMI->getOpcode() == Opcode ? DefMI : nullptr; |
630 | } |
631 | |
632 | APFloat llvm::getAPFloatFromSize(double Val, unsigned Size) { |
633 | if (Size == 32) |
634 | return APFloat(float(Val)); |
635 | if (Size == 64) |
636 | return APFloat(Val); |
637 | if (Size != 16) |
638 | llvm_unreachable("Unsupported FPConstant size" ); |
639 | bool Ignored; |
640 | APFloat APF(Val); |
641 | APF.convert(ToSemantics: APFloat::IEEEhalf(), RM: APFloat::rmNearestTiesToEven, losesInfo: &Ignored); |
642 | return APF; |
643 | } |
644 | |
645 | std::optional<APInt> llvm::ConstantFoldBinOp(unsigned Opcode, |
646 | const Register Op1, |
647 | const Register Op2, |
648 | const MachineRegisterInfo &MRI) { |
649 | auto MaybeOp2Cst = getAnyConstantVRegValWithLookThrough(VReg: Op2, MRI, LookThroughInstrs: false); |
650 | if (!MaybeOp2Cst) |
651 | return std::nullopt; |
652 | |
653 | auto MaybeOp1Cst = getAnyConstantVRegValWithLookThrough(VReg: Op1, MRI, LookThroughInstrs: false); |
654 | if (!MaybeOp1Cst) |
655 | return std::nullopt; |
656 | |
657 | const APInt &C1 = MaybeOp1Cst->Value; |
658 | const APInt &C2 = MaybeOp2Cst->Value; |
659 | switch (Opcode) { |
660 | default: |
661 | break; |
662 | case TargetOpcode::G_ADD: |
663 | case TargetOpcode::G_PTR_ADD: |
664 | return C1 + C2; |
665 | case TargetOpcode::G_AND: |
666 | return C1 & C2; |
667 | case TargetOpcode::G_ASHR: |
668 | return C1.ashr(ShiftAmt: C2); |
669 | case TargetOpcode::G_LSHR: |
670 | return C1.lshr(ShiftAmt: C2); |
671 | case TargetOpcode::G_MUL: |
672 | return C1 * C2; |
673 | case TargetOpcode::G_OR: |
674 | return C1 | C2; |
675 | case TargetOpcode::G_SHL: |
676 | return C1 << C2; |
677 | case TargetOpcode::G_SUB: |
678 | return C1 - C2; |
679 | case TargetOpcode::G_XOR: |
680 | return C1 ^ C2; |
681 | case TargetOpcode::G_UDIV: |
682 | if (!C2.getBoolValue()) |
683 | break; |
684 | return C1.udiv(RHS: C2); |
685 | case TargetOpcode::G_SDIV: |
686 | if (!C2.getBoolValue()) |
687 | break; |
688 | return C1.sdiv(RHS: C2); |
689 | case TargetOpcode::G_UREM: |
690 | if (!C2.getBoolValue()) |
691 | break; |
692 | return C1.urem(RHS: C2); |
693 | case TargetOpcode::G_SREM: |
694 | if (!C2.getBoolValue()) |
695 | break; |
696 | return C1.srem(RHS: C2); |
697 | case TargetOpcode::G_SMIN: |
698 | return APIntOps::smin(A: C1, B: C2); |
699 | case TargetOpcode::G_SMAX: |
700 | return APIntOps::smax(A: C1, B: C2); |
701 | case TargetOpcode::G_UMIN: |
702 | return APIntOps::umin(A: C1, B: C2); |
703 | case TargetOpcode::G_UMAX: |
704 | return APIntOps::umax(A: C1, B: C2); |
705 | } |
706 | |
707 | return std::nullopt; |
708 | } |
709 | |
710 | std::optional<APFloat> |
711 | llvm::ConstantFoldFPBinOp(unsigned Opcode, const Register Op1, |
712 | const Register Op2, const MachineRegisterInfo &MRI) { |
713 | const ConstantFP *Op2Cst = getConstantFPVRegVal(VReg: Op2, MRI); |
714 | if (!Op2Cst) |
715 | return std::nullopt; |
716 | |
717 | const ConstantFP *Op1Cst = getConstantFPVRegVal(VReg: Op1, MRI); |
718 | if (!Op1Cst) |
719 | return std::nullopt; |
720 | |
721 | APFloat C1 = Op1Cst->getValueAPF(); |
722 | const APFloat &C2 = Op2Cst->getValueAPF(); |
723 | switch (Opcode) { |
724 | case TargetOpcode::G_FADD: |
725 | C1.add(RHS: C2, RM: APFloat::rmNearestTiesToEven); |
726 | return C1; |
727 | case TargetOpcode::G_FSUB: |
728 | C1.subtract(RHS: C2, RM: APFloat::rmNearestTiesToEven); |
729 | return C1; |
730 | case TargetOpcode::G_FMUL: |
731 | C1.multiply(RHS: C2, RM: APFloat::rmNearestTiesToEven); |
732 | return C1; |
733 | case TargetOpcode::G_FDIV: |
734 | C1.divide(RHS: C2, RM: APFloat::rmNearestTiesToEven); |
735 | return C1; |
736 | case TargetOpcode::G_FREM: |
737 | C1.mod(RHS: C2); |
738 | return C1; |
739 | case TargetOpcode::G_FCOPYSIGN: |
740 | C1.copySign(RHS: C2); |
741 | return C1; |
742 | case TargetOpcode::G_FMINNUM: |
743 | return minnum(A: C1, B: C2); |
744 | case TargetOpcode::G_FMAXNUM: |
745 | return maxnum(A: C1, B: C2); |
746 | case TargetOpcode::G_FMINIMUM: |
747 | return minimum(A: C1, B: C2); |
748 | case TargetOpcode::G_FMAXIMUM: |
749 | return maximum(A: C1, B: C2); |
750 | case TargetOpcode::G_FMINNUM_IEEE: |
751 | case TargetOpcode::G_FMAXNUM_IEEE: |
752 | // FIXME: These operations were unfortunately named. fminnum/fmaxnum do not |
753 | // follow the IEEE behavior for signaling nans and follow libm's fmin/fmax, |
754 | // and currently there isn't a nice wrapper in APFloat for the version with |
755 | // correct snan handling. |
756 | break; |
757 | default: |
758 | break; |
759 | } |
760 | |
761 | return std::nullopt; |
762 | } |
763 | |
764 | SmallVector<APInt> |
765 | llvm::ConstantFoldVectorBinop(unsigned Opcode, const Register Op1, |
766 | const Register Op2, |
767 | const MachineRegisterInfo &MRI) { |
768 | auto *SrcVec2 = getOpcodeDef<GBuildVector>(Reg: Op2, MRI); |
769 | if (!SrcVec2) |
770 | return SmallVector<APInt>(); |
771 | |
772 | auto *SrcVec1 = getOpcodeDef<GBuildVector>(Reg: Op1, MRI); |
773 | if (!SrcVec1) |
774 | return SmallVector<APInt>(); |
775 | |
776 | SmallVector<APInt> FoldedElements; |
777 | for (unsigned Idx = 0, E = SrcVec1->getNumSources(); Idx < E; ++Idx) { |
778 | auto MaybeCst = ConstantFoldBinOp(Opcode, Op1: SrcVec1->getSourceReg(I: Idx), |
779 | Op2: SrcVec2->getSourceReg(I: Idx), MRI); |
780 | if (!MaybeCst) |
781 | return SmallVector<APInt>(); |
782 | FoldedElements.push_back(Elt: *MaybeCst); |
783 | } |
784 | return FoldedElements; |
785 | } |
786 | |
787 | bool llvm::isKnownNeverNaN(Register Val, const MachineRegisterInfo &MRI, |
788 | bool SNaN) { |
789 | const MachineInstr *DefMI = MRI.getVRegDef(Reg: Val); |
790 | if (!DefMI) |
791 | return false; |
792 | |
793 | const TargetMachine& TM = DefMI->getMF()->getTarget(); |
794 | if (DefMI->getFlag(Flag: MachineInstr::FmNoNans) || TM.Options.NoNaNsFPMath) |
795 | return true; |
796 | |
797 | // If the value is a constant, we can obviously see if it is a NaN or not. |
798 | if (const ConstantFP *FPVal = getConstantFPVRegVal(VReg: Val, MRI)) { |
799 | return !FPVal->getValueAPF().isNaN() || |
800 | (SNaN && !FPVal->getValueAPF().isSignaling()); |
801 | } |
802 | |
803 | if (DefMI->getOpcode() == TargetOpcode::G_BUILD_VECTOR) { |
804 | for (const auto &Op : DefMI->uses()) |
805 | if (!isKnownNeverNaN(Val: Op.getReg(), MRI, SNaN)) |
806 | return false; |
807 | return true; |
808 | } |
809 | |
810 | switch (DefMI->getOpcode()) { |
811 | default: |
812 | break; |
813 | case TargetOpcode::G_FADD: |
814 | case TargetOpcode::G_FSUB: |
815 | case TargetOpcode::G_FMUL: |
816 | case TargetOpcode::G_FDIV: |
817 | case TargetOpcode::G_FREM: |
818 | case TargetOpcode::G_FSIN: |
819 | case TargetOpcode::G_FCOS: |
820 | case TargetOpcode::G_FMA: |
821 | case TargetOpcode::G_FMAD: |
822 | if (SNaN) |
823 | return true; |
824 | |
825 | // TODO: Need isKnownNeverInfinity |
826 | return false; |
827 | case TargetOpcode::G_FMINNUM_IEEE: |
828 | case TargetOpcode::G_FMAXNUM_IEEE: { |
829 | if (SNaN) |
830 | return true; |
831 | // This can return a NaN if either operand is an sNaN, or if both operands |
832 | // are NaN. |
833 | return (isKnownNeverNaN(Val: DefMI->getOperand(i: 1).getReg(), MRI) && |
834 | isKnownNeverSNaN(Val: DefMI->getOperand(i: 2).getReg(), MRI)) || |
835 | (isKnownNeverSNaN(Val: DefMI->getOperand(i: 1).getReg(), MRI) && |
836 | isKnownNeverNaN(Val: DefMI->getOperand(i: 2).getReg(), MRI)); |
837 | } |
838 | case TargetOpcode::G_FMINNUM: |
839 | case TargetOpcode::G_FMAXNUM: { |
840 | // Only one needs to be known not-nan, since it will be returned if the |
841 | // other ends up being one. |
842 | return isKnownNeverNaN(Val: DefMI->getOperand(i: 1).getReg(), MRI, SNaN) || |
843 | isKnownNeverNaN(Val: DefMI->getOperand(i: 2).getReg(), MRI, SNaN); |
844 | } |
845 | } |
846 | |
847 | if (SNaN) { |
848 | // FP operations quiet. For now, just handle the ones inserted during |
849 | // legalization. |
850 | switch (DefMI->getOpcode()) { |
851 | case TargetOpcode::G_FPEXT: |
852 | case TargetOpcode::G_FPTRUNC: |
853 | case TargetOpcode::G_FCANONICALIZE: |
854 | return true; |
855 | default: |
856 | return false; |
857 | } |
858 | } |
859 | |
860 | return false; |
861 | } |
862 | |
863 | Align llvm::inferAlignFromPtrInfo(MachineFunction &MF, |
864 | const MachinePointerInfo &MPO) { |
865 | auto PSV = dyn_cast_if_present<const PseudoSourceValue *>(Val: MPO.V); |
866 | if (auto FSPV = dyn_cast_or_null<FixedStackPseudoSourceValue>(Val: PSV)) { |
867 | MachineFrameInfo &MFI = MF.getFrameInfo(); |
868 | return commonAlignment(A: MFI.getObjectAlign(ObjectIdx: FSPV->getFrameIndex()), |
869 | Offset: MPO.Offset); |
870 | } |
871 | |
872 | if (const Value *V = dyn_cast_if_present<const Value *>(Val: MPO.V)) { |
873 | const Module *M = MF.getFunction().getParent(); |
874 | return V->getPointerAlignment(DL: M->getDataLayout()); |
875 | } |
876 | |
877 | return Align(1); |
878 | } |
879 | |
880 | Register llvm::getFunctionLiveInPhysReg(MachineFunction &MF, |
881 | const TargetInstrInfo &TII, |
882 | MCRegister PhysReg, |
883 | const TargetRegisterClass &RC, |
884 | const DebugLoc &DL, LLT RegTy) { |
885 | MachineBasicBlock &EntryMBB = MF.front(); |
886 | MachineRegisterInfo &MRI = MF.getRegInfo(); |
887 | Register LiveIn = MRI.getLiveInVirtReg(PReg: PhysReg); |
888 | if (LiveIn) { |
889 | MachineInstr *Def = MRI.getVRegDef(Reg: LiveIn); |
890 | if (Def) { |
891 | // FIXME: Should the verifier check this is in the entry block? |
892 | assert(Def->getParent() == &EntryMBB && "live-in copy not in entry block" ); |
893 | return LiveIn; |
894 | } |
895 | |
896 | // It's possible the incoming argument register and copy was added during |
897 | // lowering, but later deleted due to being/becoming dead. If this happens, |
898 | // re-insert the copy. |
899 | } else { |
900 | // The live in register was not present, so add it. |
901 | LiveIn = MF.addLiveIn(PReg: PhysReg, RC: &RC); |
902 | if (RegTy.isValid()) |
903 | MRI.setType(VReg: LiveIn, Ty: RegTy); |
904 | } |
905 | |
906 | BuildMI(BB&: EntryMBB, I: EntryMBB.begin(), MIMD: DL, MCID: TII.get(Opcode: TargetOpcode::COPY), DestReg: LiveIn) |
907 | .addReg(RegNo: PhysReg); |
908 | if (!EntryMBB.isLiveIn(Reg: PhysReg)) |
909 | EntryMBB.addLiveIn(PhysReg); |
910 | return LiveIn; |
911 | } |
912 | |
913 | std::optional<APInt> llvm::ConstantFoldExtOp(unsigned Opcode, |
914 | const Register Op1, uint64_t Imm, |
915 | const MachineRegisterInfo &MRI) { |
916 | auto MaybeOp1Cst = getIConstantVRegVal(VReg: Op1, MRI); |
917 | if (MaybeOp1Cst) { |
918 | switch (Opcode) { |
919 | default: |
920 | break; |
921 | case TargetOpcode::G_SEXT_INREG: { |
922 | LLT Ty = MRI.getType(Reg: Op1); |
923 | return MaybeOp1Cst->trunc(width: Imm).sext(width: Ty.getScalarSizeInBits()); |
924 | } |
925 | } |
926 | } |
927 | return std::nullopt; |
928 | } |
929 | |
930 | std::optional<APInt> llvm::ConstantFoldCastOp(unsigned Opcode, LLT DstTy, |
931 | const Register Op0, |
932 | const MachineRegisterInfo &MRI) { |
933 | std::optional<APInt> Val = getIConstantVRegVal(VReg: Op0, MRI); |
934 | if (!Val) |
935 | return Val; |
936 | |
937 | const unsigned DstSize = DstTy.getScalarSizeInBits(); |
938 | |
939 | switch (Opcode) { |
940 | case TargetOpcode::G_SEXT: |
941 | return Val->sext(width: DstSize); |
942 | case TargetOpcode::G_ZEXT: |
943 | case TargetOpcode::G_ANYEXT: |
944 | // TODO: DAG considers target preference when constant folding any_extend. |
945 | return Val->zext(width: DstSize); |
946 | default: |
947 | break; |
948 | } |
949 | |
950 | llvm_unreachable("unexpected cast opcode to constant fold" ); |
951 | } |
952 | |
953 | std::optional<APFloat> |
954 | llvm::ConstantFoldIntToFloat(unsigned Opcode, LLT DstTy, Register Src, |
955 | const MachineRegisterInfo &MRI) { |
956 | assert(Opcode == TargetOpcode::G_SITOFP || Opcode == TargetOpcode::G_UITOFP); |
957 | if (auto MaybeSrcVal = getIConstantVRegVal(VReg: Src, MRI)) { |
958 | APFloat DstVal(getFltSemanticForLLT(Ty: DstTy)); |
959 | DstVal.convertFromAPInt(Input: *MaybeSrcVal, IsSigned: Opcode == TargetOpcode::G_SITOFP, |
960 | RM: APFloat::rmNearestTiesToEven); |
961 | return DstVal; |
962 | } |
963 | return std::nullopt; |
964 | } |
965 | |
966 | std::optional<SmallVector<unsigned>> |
967 | llvm::ConstantFoldCTLZ(Register Src, const MachineRegisterInfo &MRI) { |
968 | LLT Ty = MRI.getType(Reg: Src); |
969 | SmallVector<unsigned> FoldedCTLZs; |
970 | auto tryFoldScalar = [&](Register R) -> std::optional<unsigned> { |
971 | auto MaybeCst = getIConstantVRegVal(VReg: R, MRI); |
972 | if (!MaybeCst) |
973 | return std::nullopt; |
974 | return MaybeCst->countl_zero(); |
975 | }; |
976 | if (Ty.isVector()) { |
977 | // Try to constant fold each element. |
978 | auto *BV = getOpcodeDef<GBuildVector>(Reg: Src, MRI); |
979 | if (!BV) |
980 | return std::nullopt; |
981 | for (unsigned SrcIdx = 0; SrcIdx < BV->getNumSources(); ++SrcIdx) { |
982 | if (auto MaybeFold = tryFoldScalar(BV->getSourceReg(I: SrcIdx))) { |
983 | FoldedCTLZs.emplace_back(Args&: *MaybeFold); |
984 | continue; |
985 | } |
986 | return std::nullopt; |
987 | } |
988 | return FoldedCTLZs; |
989 | } |
990 | if (auto MaybeCst = tryFoldScalar(Src)) { |
991 | FoldedCTLZs.emplace_back(Args&: *MaybeCst); |
992 | return FoldedCTLZs; |
993 | } |
994 | return std::nullopt; |
995 | } |
996 | |
997 | bool llvm::isKnownToBeAPowerOfTwo(Register Reg, const MachineRegisterInfo &MRI, |
998 | GISelKnownBits *KB) { |
999 | std::optional<DefinitionAndSourceRegister> DefSrcReg = |
1000 | getDefSrcRegIgnoringCopies(Reg, MRI); |
1001 | if (!DefSrcReg) |
1002 | return false; |
1003 | |
1004 | const MachineInstr &MI = *DefSrcReg->MI; |
1005 | const LLT Ty = MRI.getType(Reg); |
1006 | |
1007 | switch (MI.getOpcode()) { |
1008 | case TargetOpcode::G_CONSTANT: { |
1009 | unsigned BitWidth = Ty.getScalarSizeInBits(); |
1010 | const ConstantInt *CI = MI.getOperand(i: 1).getCImm(); |
1011 | return CI->getValue().zextOrTrunc(width: BitWidth).isPowerOf2(); |
1012 | } |
1013 | case TargetOpcode::G_SHL: { |
1014 | // A left-shift of a constant one will have exactly one bit set because |
1015 | // shifting the bit off the end is undefined. |
1016 | |
1017 | // TODO: Constant splat |
1018 | if (auto ConstLHS = getIConstantVRegVal(VReg: MI.getOperand(i: 1).getReg(), MRI)) { |
1019 | if (*ConstLHS == 1) |
1020 | return true; |
1021 | } |
1022 | |
1023 | break; |
1024 | } |
1025 | case TargetOpcode::G_LSHR: { |
1026 | if (auto ConstLHS = getIConstantVRegVal(VReg: MI.getOperand(i: 1).getReg(), MRI)) { |
1027 | if (ConstLHS->isSignMask()) |
1028 | return true; |
1029 | } |
1030 | |
1031 | break; |
1032 | } |
1033 | case TargetOpcode::G_BUILD_VECTOR: { |
1034 | // TODO: Probably should have a recursion depth guard since you could have |
1035 | // bitcasted vector elements. |
1036 | for (const MachineOperand &MO : llvm::drop_begin(RangeOrContainer: MI.operands())) |
1037 | if (!isKnownToBeAPowerOfTwo(Reg: MO.getReg(), MRI, KB)) |
1038 | return false; |
1039 | |
1040 | return true; |
1041 | } |
1042 | case TargetOpcode::G_BUILD_VECTOR_TRUNC: { |
1043 | // Only handle constants since we would need to know if number of leading |
1044 | // zeros is greater than the truncation amount. |
1045 | const unsigned BitWidth = Ty.getScalarSizeInBits(); |
1046 | for (const MachineOperand &MO : llvm::drop_begin(RangeOrContainer: MI.operands())) { |
1047 | auto Const = getIConstantVRegVal(VReg: MO.getReg(), MRI); |
1048 | if (!Const || !Const->zextOrTrunc(width: BitWidth).isPowerOf2()) |
1049 | return false; |
1050 | } |
1051 | |
1052 | return true; |
1053 | } |
1054 | default: |
1055 | break; |
1056 | } |
1057 | |
1058 | if (!KB) |
1059 | return false; |
1060 | |
1061 | // More could be done here, though the above checks are enough |
1062 | // to handle some common cases. |
1063 | |
1064 | // Fall back to computeKnownBits to catch other known cases. |
1065 | KnownBits Known = KB->getKnownBits(R: Reg); |
1066 | return (Known.countMaxPopulation() == 1) && (Known.countMinPopulation() == 1); |
1067 | } |
1068 | |
1069 | void llvm::getSelectionDAGFallbackAnalysisUsage(AnalysisUsage &AU) { |
1070 | AU.addPreserved<StackProtector>(); |
1071 | } |
1072 | |
1073 | LLT llvm::getLCMType(LLT OrigTy, LLT TargetTy) { |
1074 | if (OrigTy.getSizeInBits() == TargetTy.getSizeInBits()) |
1075 | return OrigTy; |
1076 | |
1077 | if (OrigTy.isVector() && TargetTy.isVector()) { |
1078 | LLT OrigElt = OrigTy.getElementType(); |
1079 | LLT TargetElt = TargetTy.getElementType(); |
1080 | |
1081 | // TODO: The docstring for this function says the intention is to use this |
1082 | // function to build MERGE/UNMERGE instructions. It won't be the case that |
1083 | // we generate a MERGE/UNMERGE between fixed and scalable vector types. We |
1084 | // could implement getLCMType between the two in the future if there was a |
1085 | // need, but it is not worth it now as this function should not be used in |
1086 | // that way. |
1087 | assert(((OrigTy.isScalableVector() && !TargetTy.isFixedVector()) || |
1088 | (OrigTy.isFixedVector() && !TargetTy.isScalableVector())) && |
1089 | "getLCMType not implemented between fixed and scalable vectors." ); |
1090 | |
1091 | if (OrigElt.getSizeInBits() == TargetElt.getSizeInBits()) { |
1092 | int GCDMinElts = std::gcd(m: OrigTy.getElementCount().getKnownMinValue(), |
1093 | n: TargetTy.getElementCount().getKnownMinValue()); |
1094 | // Prefer the original element type. |
1095 | ElementCount Mul = OrigTy.getElementCount().multiplyCoefficientBy( |
1096 | RHS: TargetTy.getElementCount().getKnownMinValue()); |
1097 | return LLT::vector(EC: Mul.divideCoefficientBy(RHS: GCDMinElts), |
1098 | ScalarTy: OrigTy.getElementType()); |
1099 | } |
1100 | unsigned LCM = std::lcm(m: OrigTy.getSizeInBits().getKnownMinValue(), |
1101 | n: TargetTy.getSizeInBits().getKnownMinValue()); |
1102 | return LLT::vector( |
1103 | EC: ElementCount::get(MinVal: LCM / OrigElt.getSizeInBits(), Scalable: OrigTy.isScalable()), |
1104 | ScalarTy: OrigElt); |
1105 | } |
1106 | |
1107 | // One type is scalar, one type is vector |
1108 | if (OrigTy.isVector() || TargetTy.isVector()) { |
1109 | LLT VecTy = OrigTy.isVector() ? OrigTy : TargetTy; |
1110 | LLT ScalarTy = OrigTy.isVector() ? TargetTy : OrigTy; |
1111 | LLT EltTy = VecTy.getElementType(); |
1112 | LLT OrigEltTy = OrigTy.isVector() ? OrigTy.getElementType() : OrigTy; |
1113 | |
1114 | // Prefer scalar type from OrigTy. |
1115 | if (EltTy.getSizeInBits() == ScalarTy.getSizeInBits()) |
1116 | return LLT::vector(EC: VecTy.getElementCount(), ScalarTy: OrigEltTy); |
1117 | |
1118 | // Different size scalars. Create vector with the same total size. |
1119 | // LCM will take fixed/scalable from VecTy. |
1120 | unsigned LCM = std::lcm(m: EltTy.getSizeInBits().getFixedValue() * |
1121 | VecTy.getElementCount().getKnownMinValue(), |
1122 | n: ScalarTy.getSizeInBits().getFixedValue()); |
1123 | // Prefer type from OrigTy |
1124 | return LLT::vector(EC: ElementCount::get(MinVal: LCM / OrigEltTy.getSizeInBits(), |
1125 | Scalable: VecTy.getElementCount().isScalable()), |
1126 | ScalarTy: OrigEltTy); |
1127 | } |
1128 | |
1129 | // At this point, both types are scalars of different size |
1130 | unsigned LCM = std::lcm(m: OrigTy.getSizeInBits().getFixedValue(), |
1131 | n: TargetTy.getSizeInBits().getFixedValue()); |
1132 | // Preserve pointer types. |
1133 | if (LCM == OrigTy.getSizeInBits()) |
1134 | return OrigTy; |
1135 | if (LCM == TargetTy.getSizeInBits()) |
1136 | return TargetTy; |
1137 | return LLT::scalar(SizeInBits: LCM); |
1138 | } |
1139 | |
1140 | LLT llvm::getCoverTy(LLT OrigTy, LLT TargetTy) { |
1141 | |
1142 | if ((OrigTy.isScalableVector() && TargetTy.isFixedVector()) || |
1143 | (OrigTy.isFixedVector() && TargetTy.isScalableVector())) |
1144 | llvm_unreachable( |
1145 | "getCoverTy not implemented between fixed and scalable vectors." ); |
1146 | |
1147 | if (!OrigTy.isVector() || !TargetTy.isVector() || OrigTy == TargetTy || |
1148 | (OrigTy.getScalarSizeInBits() != TargetTy.getScalarSizeInBits())) |
1149 | return getLCMType(OrigTy, TargetTy); |
1150 | |
1151 | unsigned OrigTyNumElts = OrigTy.getElementCount().getKnownMinValue(); |
1152 | unsigned TargetTyNumElts = TargetTy.getElementCount().getKnownMinValue(); |
1153 | if (OrigTyNumElts % TargetTyNumElts == 0) |
1154 | return OrigTy; |
1155 | |
1156 | unsigned NumElts = alignTo(Value: OrigTyNumElts, Align: TargetTyNumElts); |
1157 | return LLT::scalarOrVector(EC: ElementCount::getFixed(MinVal: NumElts), |
1158 | ScalarTy: OrigTy.getElementType()); |
1159 | } |
1160 | |
1161 | LLT llvm::getGCDType(LLT OrigTy, LLT TargetTy) { |
1162 | if (OrigTy.getSizeInBits() == TargetTy.getSizeInBits()) |
1163 | return OrigTy; |
1164 | |
1165 | if (OrigTy.isVector() && TargetTy.isVector()) { |
1166 | LLT OrigElt = OrigTy.getElementType(); |
1167 | |
1168 | // TODO: The docstring for this function says the intention is to use this |
1169 | // function to build MERGE/UNMERGE instructions. It won't be the case that |
1170 | // we generate a MERGE/UNMERGE between fixed and scalable vector types. We |
1171 | // could implement getGCDType between the two in the future if there was a |
1172 | // need, but it is not worth it now as this function should not be used in |
1173 | // that way. |
1174 | assert(((OrigTy.isScalableVector() && !TargetTy.isFixedVector()) || |
1175 | (OrigTy.isFixedVector() && !TargetTy.isScalableVector())) && |
1176 | "getGCDType not implemented between fixed and scalable vectors." ); |
1177 | |
1178 | unsigned GCD = std::gcd(m: OrigTy.getSizeInBits().getKnownMinValue(), |
1179 | n: TargetTy.getSizeInBits().getKnownMinValue()); |
1180 | if (GCD == OrigElt.getSizeInBits()) |
1181 | return LLT::scalarOrVector(EC: ElementCount::get(MinVal: 1, Scalable: OrigTy.isScalable()), |
1182 | ScalarTy: OrigElt); |
1183 | |
1184 | // Cannot produce original element type, but both have vscale in common. |
1185 | if (GCD < OrigElt.getSizeInBits()) |
1186 | return LLT::scalarOrVector(EC: ElementCount::get(MinVal: 1, Scalable: OrigTy.isScalable()), |
1187 | ScalarSize: GCD); |
1188 | |
1189 | return LLT::vector( |
1190 | EC: ElementCount::get(MinVal: GCD / OrigElt.getSizeInBits().getFixedValue(), |
1191 | Scalable: OrigTy.isScalable()), |
1192 | ScalarTy: OrigElt); |
1193 | } |
1194 | |
1195 | // If one type is vector and the element size matches the scalar size, then |
1196 | // the gcd is the scalar type. |
1197 | if (OrigTy.isVector() && |
1198 | OrigTy.getElementType().getSizeInBits() == TargetTy.getSizeInBits()) |
1199 | return OrigTy.getElementType(); |
1200 | if (TargetTy.isVector() && |
1201 | TargetTy.getElementType().getSizeInBits() == OrigTy.getSizeInBits()) |
1202 | return OrigTy; |
1203 | |
1204 | // At this point, both types are either scalars of different type or one is a |
1205 | // vector and one is a scalar. If both types are scalars, the GCD type is the |
1206 | // GCD between the two scalar sizes. If one is vector and one is scalar, then |
1207 | // the GCD type is the GCD between the scalar and the vector element size. |
1208 | LLT OrigScalar = OrigTy.getScalarType(); |
1209 | LLT TargetScalar = TargetTy.getScalarType(); |
1210 | unsigned GCD = std::gcd(m: OrigScalar.getSizeInBits().getFixedValue(), |
1211 | n: TargetScalar.getSizeInBits().getFixedValue()); |
1212 | return LLT::scalar(SizeInBits: GCD); |
1213 | } |
1214 | |
1215 | std::optional<int> llvm::getSplatIndex(MachineInstr &MI) { |
1216 | assert(MI.getOpcode() == TargetOpcode::G_SHUFFLE_VECTOR && |
1217 | "Only G_SHUFFLE_VECTOR can have a splat index!" ); |
1218 | ArrayRef<int> Mask = MI.getOperand(i: 3).getShuffleMask(); |
1219 | auto FirstDefinedIdx = find_if(Range&: Mask, P: [](int Elt) { return Elt >= 0; }); |
1220 | |
1221 | // If all elements are undefined, this shuffle can be considered a splat. |
1222 | // Return 0 for better potential for callers to simplify. |
1223 | if (FirstDefinedIdx == Mask.end()) |
1224 | return 0; |
1225 | |
1226 | // Make sure all remaining elements are either undef or the same |
1227 | // as the first non-undef value. |
1228 | int SplatValue = *FirstDefinedIdx; |
1229 | if (any_of(Range: make_range(x: std::next(x: FirstDefinedIdx), y: Mask.end()), |
1230 | P: [&SplatValue](int Elt) { return Elt >= 0 && Elt != SplatValue; })) |
1231 | return std::nullopt; |
1232 | |
1233 | return SplatValue; |
1234 | } |
1235 | |
1236 | static bool isBuildVectorOp(unsigned Opcode) { |
1237 | return Opcode == TargetOpcode::G_BUILD_VECTOR || |
1238 | Opcode == TargetOpcode::G_BUILD_VECTOR_TRUNC; |
1239 | } |
1240 | |
1241 | namespace { |
1242 | |
1243 | std::optional<ValueAndVReg> getAnyConstantSplat(Register VReg, |
1244 | const MachineRegisterInfo &MRI, |
1245 | bool AllowUndef) { |
1246 | MachineInstr *MI = getDefIgnoringCopies(Reg: VReg, MRI); |
1247 | if (!MI) |
1248 | return std::nullopt; |
1249 | |
1250 | bool isConcatVectorsOp = MI->getOpcode() == TargetOpcode::G_CONCAT_VECTORS; |
1251 | if (!isBuildVectorOp(Opcode: MI->getOpcode()) && !isConcatVectorsOp) |
1252 | return std::nullopt; |
1253 | |
1254 | std::optional<ValueAndVReg> SplatValAndReg; |
1255 | for (MachineOperand &Op : MI->uses()) { |
1256 | Register Element = Op.getReg(); |
1257 | // If we have a G_CONCAT_VECTOR, we recursively look into the |
1258 | // vectors that we're concatenating to see if they're splats. |
1259 | auto ElementValAndReg = |
1260 | isConcatVectorsOp |
1261 | ? getAnyConstantSplat(VReg: Element, MRI, AllowUndef) |
1262 | : getAnyConstantVRegValWithLookThrough(VReg: Element, MRI, LookThroughInstrs: true, LookThroughAnyExt: true); |
1263 | |
1264 | // If AllowUndef, treat undef as value that will result in a constant splat. |
1265 | if (!ElementValAndReg) { |
1266 | if (AllowUndef && isa<GImplicitDef>(Val: MRI.getVRegDef(Reg: Element))) |
1267 | continue; |
1268 | return std::nullopt; |
1269 | } |
1270 | |
1271 | // Record splat value |
1272 | if (!SplatValAndReg) |
1273 | SplatValAndReg = ElementValAndReg; |
1274 | |
1275 | // Different constant than the one already recorded, not a constant splat. |
1276 | if (SplatValAndReg->Value != ElementValAndReg->Value) |
1277 | return std::nullopt; |
1278 | } |
1279 | |
1280 | return SplatValAndReg; |
1281 | } |
1282 | |
1283 | } // end anonymous namespace |
1284 | |
1285 | bool llvm::isBuildVectorConstantSplat(const Register Reg, |
1286 | const MachineRegisterInfo &MRI, |
1287 | int64_t SplatValue, bool AllowUndef) { |
1288 | if (auto SplatValAndReg = getAnyConstantSplat(VReg: Reg, MRI, AllowUndef)) |
1289 | return mi_match(R: SplatValAndReg->VReg, MRI, P: m_SpecificICst(RequestedValue: SplatValue)); |
1290 | return false; |
1291 | } |
1292 | |
1293 | bool llvm::isBuildVectorConstantSplat(const MachineInstr &MI, |
1294 | const MachineRegisterInfo &MRI, |
1295 | int64_t SplatValue, bool AllowUndef) { |
1296 | return isBuildVectorConstantSplat(Reg: MI.getOperand(i: 0).getReg(), MRI, SplatValue, |
1297 | AllowUndef); |
1298 | } |
1299 | |
1300 | std::optional<APInt> |
1301 | llvm::getIConstantSplatVal(const Register Reg, const MachineRegisterInfo &MRI) { |
1302 | if (auto SplatValAndReg = |
1303 | getAnyConstantSplat(VReg: Reg, MRI, /* AllowUndef */ false)) { |
1304 | if (std::optional<ValueAndVReg> ValAndVReg = |
1305 | getIConstantVRegValWithLookThrough(VReg: SplatValAndReg->VReg, MRI)) |
1306 | return ValAndVReg->Value; |
1307 | } |
1308 | |
1309 | return std::nullopt; |
1310 | } |
1311 | |
1312 | std::optional<APInt> |
1313 | llvm::getIConstantSplatVal(const MachineInstr &MI, |
1314 | const MachineRegisterInfo &MRI) { |
1315 | return getIConstantSplatVal(Reg: MI.getOperand(i: 0).getReg(), MRI); |
1316 | } |
1317 | |
1318 | std::optional<int64_t> |
1319 | llvm::getIConstantSplatSExtVal(const Register Reg, |
1320 | const MachineRegisterInfo &MRI) { |
1321 | if (auto SplatValAndReg = |
1322 | getAnyConstantSplat(VReg: Reg, MRI, /* AllowUndef */ false)) |
1323 | return getIConstantVRegSExtVal(VReg: SplatValAndReg->VReg, MRI); |
1324 | return std::nullopt; |
1325 | } |
1326 | |
1327 | std::optional<int64_t> |
1328 | llvm::getIConstantSplatSExtVal(const MachineInstr &MI, |
1329 | const MachineRegisterInfo &MRI) { |
1330 | return getIConstantSplatSExtVal(Reg: MI.getOperand(i: 0).getReg(), MRI); |
1331 | } |
1332 | |
1333 | std::optional<FPValueAndVReg> |
1334 | llvm::getFConstantSplat(Register VReg, const MachineRegisterInfo &MRI, |
1335 | bool AllowUndef) { |
1336 | if (auto SplatValAndReg = getAnyConstantSplat(VReg, MRI, AllowUndef)) |
1337 | return getFConstantVRegValWithLookThrough(VReg: SplatValAndReg->VReg, MRI); |
1338 | return std::nullopt; |
1339 | } |
1340 | |
1341 | bool llvm::isBuildVectorAllZeros(const MachineInstr &MI, |
1342 | const MachineRegisterInfo &MRI, |
1343 | bool AllowUndef) { |
1344 | return isBuildVectorConstantSplat(MI, MRI, SplatValue: 0, AllowUndef); |
1345 | } |
1346 | |
1347 | bool llvm::isBuildVectorAllOnes(const MachineInstr &MI, |
1348 | const MachineRegisterInfo &MRI, |
1349 | bool AllowUndef) { |
1350 | return isBuildVectorConstantSplat(MI, MRI, SplatValue: -1, AllowUndef); |
1351 | } |
1352 | |
1353 | std::optional<RegOrConstant> |
1354 | llvm::getVectorSplat(const MachineInstr &MI, const MachineRegisterInfo &MRI) { |
1355 | unsigned Opc = MI.getOpcode(); |
1356 | if (!isBuildVectorOp(Opcode: Opc)) |
1357 | return std::nullopt; |
1358 | if (auto Splat = getIConstantSplatSExtVal(MI, MRI)) |
1359 | return RegOrConstant(*Splat); |
1360 | auto Reg = MI.getOperand(i: 1).getReg(); |
1361 | if (any_of(Range: drop_begin(RangeOrContainer: MI.operands(), N: 2), |
1362 | P: [&Reg](const MachineOperand &Op) { return Op.getReg() != Reg; })) |
1363 | return std::nullopt; |
1364 | return RegOrConstant(Reg); |
1365 | } |
1366 | |
1367 | static bool isConstantScalar(const MachineInstr &MI, |
1368 | const MachineRegisterInfo &MRI, |
1369 | bool AllowFP = true, |
1370 | bool AllowOpaqueConstants = true) { |
1371 | switch (MI.getOpcode()) { |
1372 | case TargetOpcode::G_CONSTANT: |
1373 | case TargetOpcode::G_IMPLICIT_DEF: |
1374 | return true; |
1375 | case TargetOpcode::G_FCONSTANT: |
1376 | return AllowFP; |
1377 | case TargetOpcode::G_GLOBAL_VALUE: |
1378 | case TargetOpcode::G_FRAME_INDEX: |
1379 | case TargetOpcode::G_BLOCK_ADDR: |
1380 | case TargetOpcode::G_JUMP_TABLE: |
1381 | return AllowOpaqueConstants; |
1382 | default: |
1383 | return false; |
1384 | } |
1385 | } |
1386 | |
1387 | bool llvm::isConstantOrConstantVector(MachineInstr &MI, |
1388 | const MachineRegisterInfo &MRI) { |
1389 | Register Def = MI.getOperand(i: 0).getReg(); |
1390 | if (auto C = getIConstantVRegValWithLookThrough(VReg: Def, MRI)) |
1391 | return true; |
1392 | GBuildVector *BV = dyn_cast<GBuildVector>(Val: &MI); |
1393 | if (!BV) |
1394 | return false; |
1395 | for (unsigned SrcIdx = 0; SrcIdx < BV->getNumSources(); ++SrcIdx) { |
1396 | if (getIConstantVRegValWithLookThrough(VReg: BV->getSourceReg(I: SrcIdx), MRI) || |
1397 | getOpcodeDef<GImplicitDef>(Reg: BV->getSourceReg(I: SrcIdx), MRI)) |
1398 | continue; |
1399 | return false; |
1400 | } |
1401 | return true; |
1402 | } |
1403 | |
1404 | bool llvm::isConstantOrConstantVector(const MachineInstr &MI, |
1405 | const MachineRegisterInfo &MRI, |
1406 | bool AllowFP, bool AllowOpaqueConstants) { |
1407 | if (isConstantScalar(MI, MRI, AllowFP, AllowOpaqueConstants)) |
1408 | return true; |
1409 | |
1410 | if (!isBuildVectorOp(Opcode: MI.getOpcode())) |
1411 | return false; |
1412 | |
1413 | const unsigned NumOps = MI.getNumOperands(); |
1414 | for (unsigned I = 1; I != NumOps; ++I) { |
1415 | const MachineInstr *ElementDef = MRI.getVRegDef(Reg: MI.getOperand(i: I).getReg()); |
1416 | if (!isConstantScalar(MI: *ElementDef, MRI, AllowFP, AllowOpaqueConstants)) |
1417 | return false; |
1418 | } |
1419 | |
1420 | return true; |
1421 | } |
1422 | |
1423 | std::optional<APInt> |
1424 | llvm::isConstantOrConstantSplatVector(MachineInstr &MI, |
1425 | const MachineRegisterInfo &MRI) { |
1426 | Register Def = MI.getOperand(i: 0).getReg(); |
1427 | if (auto C = getIConstantVRegValWithLookThrough(VReg: Def, MRI)) |
1428 | return C->Value; |
1429 | auto MaybeCst = getIConstantSplatSExtVal(MI, MRI); |
1430 | if (!MaybeCst) |
1431 | return std::nullopt; |
1432 | const unsigned ScalarSize = MRI.getType(Reg: Def).getScalarSizeInBits(); |
1433 | return APInt(ScalarSize, *MaybeCst, true); |
1434 | } |
1435 | |
1436 | bool llvm::isNullOrNullSplat(const MachineInstr &MI, |
1437 | const MachineRegisterInfo &MRI, bool AllowUndefs) { |
1438 | switch (MI.getOpcode()) { |
1439 | case TargetOpcode::G_IMPLICIT_DEF: |
1440 | return AllowUndefs; |
1441 | case TargetOpcode::G_CONSTANT: |
1442 | return MI.getOperand(i: 1).getCImm()->isNullValue(); |
1443 | case TargetOpcode::G_FCONSTANT: { |
1444 | const ConstantFP *FPImm = MI.getOperand(i: 1).getFPImm(); |
1445 | return FPImm->isZero() && !FPImm->isNegative(); |
1446 | } |
1447 | default: |
1448 | if (!AllowUndefs) // TODO: isBuildVectorAllZeros assumes undef is OK already |
1449 | return false; |
1450 | return isBuildVectorAllZeros(MI, MRI); |
1451 | } |
1452 | } |
1453 | |
1454 | bool llvm::isAllOnesOrAllOnesSplat(const MachineInstr &MI, |
1455 | const MachineRegisterInfo &MRI, |
1456 | bool AllowUndefs) { |
1457 | switch (MI.getOpcode()) { |
1458 | case TargetOpcode::G_IMPLICIT_DEF: |
1459 | return AllowUndefs; |
1460 | case TargetOpcode::G_CONSTANT: |
1461 | return MI.getOperand(i: 1).getCImm()->isAllOnesValue(); |
1462 | default: |
1463 | if (!AllowUndefs) // TODO: isBuildVectorAllOnes assumes undef is OK already |
1464 | return false; |
1465 | return isBuildVectorAllOnes(MI, MRI); |
1466 | } |
1467 | } |
1468 | |
1469 | bool llvm::matchUnaryPredicate( |
1470 | const MachineRegisterInfo &MRI, Register Reg, |
1471 | std::function<bool(const Constant *ConstVal)> Match, bool AllowUndefs) { |
1472 | |
1473 | const MachineInstr *Def = getDefIgnoringCopies(Reg, MRI); |
1474 | if (AllowUndefs && Def->getOpcode() == TargetOpcode::G_IMPLICIT_DEF) |
1475 | return Match(nullptr); |
1476 | |
1477 | // TODO: Also handle fconstant |
1478 | if (Def->getOpcode() == TargetOpcode::G_CONSTANT) |
1479 | return Match(Def->getOperand(i: 1).getCImm()); |
1480 | |
1481 | if (Def->getOpcode() != TargetOpcode::G_BUILD_VECTOR) |
1482 | return false; |
1483 | |
1484 | for (unsigned I = 1, E = Def->getNumOperands(); I != E; ++I) { |
1485 | Register SrcElt = Def->getOperand(i: I).getReg(); |
1486 | const MachineInstr *SrcDef = getDefIgnoringCopies(Reg: SrcElt, MRI); |
1487 | if (AllowUndefs && SrcDef->getOpcode() == TargetOpcode::G_IMPLICIT_DEF) { |
1488 | if (!Match(nullptr)) |
1489 | return false; |
1490 | continue; |
1491 | } |
1492 | |
1493 | if (SrcDef->getOpcode() != TargetOpcode::G_CONSTANT || |
1494 | !Match(SrcDef->getOperand(i: 1).getCImm())) |
1495 | return false; |
1496 | } |
1497 | |
1498 | return true; |
1499 | } |
1500 | |
1501 | bool llvm::isConstTrueVal(const TargetLowering &TLI, int64_t Val, bool IsVector, |
1502 | bool IsFP) { |
1503 | switch (TLI.getBooleanContents(isVec: IsVector, isFloat: IsFP)) { |
1504 | case TargetLowering::UndefinedBooleanContent: |
1505 | return Val & 0x1; |
1506 | case TargetLowering::ZeroOrOneBooleanContent: |
1507 | return Val == 1; |
1508 | case TargetLowering::ZeroOrNegativeOneBooleanContent: |
1509 | return Val == -1; |
1510 | } |
1511 | llvm_unreachable("Invalid boolean contents" ); |
1512 | } |
1513 | |
1514 | bool llvm::isConstFalseVal(const TargetLowering &TLI, int64_t Val, |
1515 | bool IsVector, bool IsFP) { |
1516 | switch (TLI.getBooleanContents(isVec: IsVector, isFloat: IsFP)) { |
1517 | case TargetLowering::UndefinedBooleanContent: |
1518 | return ~Val & 0x1; |
1519 | case TargetLowering::ZeroOrOneBooleanContent: |
1520 | case TargetLowering::ZeroOrNegativeOneBooleanContent: |
1521 | return Val == 0; |
1522 | } |
1523 | llvm_unreachable("Invalid boolean contents" ); |
1524 | } |
1525 | |
1526 | int64_t llvm::getICmpTrueVal(const TargetLowering &TLI, bool IsVector, |
1527 | bool IsFP) { |
1528 | switch (TLI.getBooleanContents(isVec: IsVector, isFloat: IsFP)) { |
1529 | case TargetLowering::UndefinedBooleanContent: |
1530 | case TargetLowering::ZeroOrOneBooleanContent: |
1531 | return 1; |
1532 | case TargetLowering::ZeroOrNegativeOneBooleanContent: |
1533 | return -1; |
1534 | } |
1535 | llvm_unreachable("Invalid boolean contents" ); |
1536 | } |
1537 | |
1538 | bool llvm::shouldOptForSize(const MachineBasicBlock &MBB, |
1539 | ProfileSummaryInfo *PSI, BlockFrequencyInfo *BFI) { |
1540 | const auto &F = MBB.getParent()->getFunction(); |
1541 | return F.hasOptSize() || F.hasMinSize() || |
1542 | llvm::shouldOptimizeForSize(BB: MBB.getBasicBlock(), PSI, BFI); |
1543 | } |
1544 | |
1545 | void llvm::saveUsesAndErase(MachineInstr &MI, MachineRegisterInfo &MRI, |
1546 | LostDebugLocObserver *LocObserver, |
1547 | SmallInstListTy &DeadInstChain) { |
1548 | for (MachineOperand &Op : MI.uses()) { |
1549 | if (Op.isReg() && Op.getReg().isVirtual()) |
1550 | DeadInstChain.insert(I: MRI.getVRegDef(Reg: Op.getReg())); |
1551 | } |
1552 | LLVM_DEBUG(dbgs() << MI << "Is dead; erasing.\n" ); |
1553 | DeadInstChain.remove(I: &MI); |
1554 | MI.eraseFromParent(); |
1555 | if (LocObserver) |
1556 | LocObserver->checkpoint(CheckDebugLocs: false); |
1557 | } |
1558 | |
1559 | void llvm::eraseInstrs(ArrayRef<MachineInstr *> DeadInstrs, |
1560 | MachineRegisterInfo &MRI, |
1561 | LostDebugLocObserver *LocObserver) { |
1562 | SmallInstListTy DeadInstChain; |
1563 | for (MachineInstr *MI : DeadInstrs) |
1564 | saveUsesAndErase(MI&: *MI, MRI, LocObserver, DeadInstChain); |
1565 | |
1566 | while (!DeadInstChain.empty()) { |
1567 | MachineInstr *Inst = DeadInstChain.pop_back_val(); |
1568 | if (!isTriviallyDead(MI: *Inst, MRI)) |
1569 | continue; |
1570 | saveUsesAndErase(MI&: *Inst, MRI, LocObserver, DeadInstChain); |
1571 | } |
1572 | } |
1573 | |
1574 | void llvm::eraseInstr(MachineInstr &MI, MachineRegisterInfo &MRI, |
1575 | LostDebugLocObserver *LocObserver) { |
1576 | return eraseInstrs(DeadInstrs: {&MI}, MRI, LocObserver); |
1577 | } |
1578 | |
1579 | void llvm::salvageDebugInfo(const MachineRegisterInfo &MRI, MachineInstr &MI) { |
1580 | for (auto &Def : MI.defs()) { |
1581 | assert(Def.isReg() && "Must be a reg" ); |
1582 | |
1583 | SmallVector<MachineOperand *, 16> DbgUsers; |
1584 | for (auto &MOUse : MRI.use_operands(Reg: Def.getReg())) { |
1585 | MachineInstr *DbgValue = MOUse.getParent(); |
1586 | // Ignore partially formed DBG_VALUEs. |
1587 | if (DbgValue->isNonListDebugValue() && DbgValue->getNumOperands() == 4) { |
1588 | DbgUsers.push_back(Elt: &MOUse); |
1589 | } |
1590 | } |
1591 | |
1592 | if (!DbgUsers.empty()) { |
1593 | salvageDebugInfoForDbgValue(MRI, MI, DbgUsers); |
1594 | } |
1595 | } |
1596 | } |
1597 | |