xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp (revision 9f23cbd6cae82fd77edfad7173432fa8dccd0a95) 
1 //===- SIMachineFunctionInfo.cpp - SI Machine Function Info ---------------===//
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 #include "SIMachineFunctionInfo.h"
10 #include "AMDGPUTargetMachine.h"
11 #include "AMDGPUSubtarget.h"
12 #include "SIRegisterInfo.h"
13 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
14 #include "Utils/AMDGPUBaseInfo.h"
15 #include "llvm/CodeGen/LiveIntervals.h"
16 #include "llvm/CodeGen/MachineBasicBlock.h"
17 #include "llvm/CodeGen/MachineFrameInfo.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/CodeGen/MachineRegisterInfo.h"
20 #include "llvm/CodeGen/MIRParser/MIParser.h"
21 #include "llvm/IR/CallingConv.h"
22 #include "llvm/IR/DiagnosticInfo.h"
23 #include "llvm/IR/Function.h"
24 #include <cassert>
25 #include <optional>
26 #include <vector>
27 
28 #define MAX_LANES 64
29 
30 using namespace llvm;
31 
32 const GCNTargetMachine &getTM(const GCNSubtarget *STI) {
33   const SITargetLowering *TLI = STI->getTargetLowering();
34   return static_cast<const GCNTargetMachine &>(TLI->getTargetMachine());
35 }
36 
37 SIMachineFunctionInfo::SIMachineFunctionInfo(const Function &F,
38                                              const GCNSubtarget *STI)
39   : AMDGPUMachineFunction(F, *STI),
40     Mode(F),
41     GWSResourcePSV(getTM(STI)),
42     PrivateSegmentBuffer(false),
43     DispatchPtr(false),
44     QueuePtr(false),
45     KernargSegmentPtr(false),
46     DispatchID(false),
47     FlatScratchInit(false),
48     WorkGroupIDX(false),
49     WorkGroupIDY(false),
50     WorkGroupIDZ(false),
51     WorkGroupInfo(false),
52     LDSKernelId(false),
53     PrivateSegmentWaveByteOffset(false),
54     WorkItemIDX(false),
55     WorkItemIDY(false),
56     WorkItemIDZ(false),
57     ImplicitBufferPtr(false),
58     ImplicitArgPtr(false),
59     GITPtrHigh(0xffffffff),
60     HighBitsOf32BitAddress(0) {
61   const GCNSubtarget &ST = *static_cast<const GCNSubtarget *>(STI);
62   FlatWorkGroupSizes = ST.getFlatWorkGroupSizes(F);
63   WavesPerEU = ST.getWavesPerEU(F);
64 
65   Occupancy = ST.computeOccupancy(F, getLDSSize());
66   CallingConv::ID CC = F.getCallingConv();
67 
68   // FIXME: Should have analysis or something rather than attribute to detect
69   // calls.
70   const bool HasCalls = F.hasFnAttribute("amdgpu-calls");
71 
72   const bool IsKernel = CC == CallingConv::AMDGPU_KERNEL ||
73                         CC == CallingConv::SPIR_KERNEL;
74 
75   if (IsKernel) {
76     if (!F.arg_empty() || ST.getImplicitArgNumBytes(F) != 0)
77       KernargSegmentPtr = true;
78     WorkGroupIDX = true;
79     WorkItemIDX = true;
80   } else if (CC == CallingConv::AMDGPU_PS) {
81     PSInputAddr = AMDGPU::getInitialPSInputAddr(F);
82   }
83 
84   MayNeedAGPRs = ST.hasMAIInsts();
85 
86   if (!isEntryFunction()) {
87     if (CC != CallingConv::AMDGPU_Gfx)
88       ArgInfo = AMDGPUArgumentUsageInfo::FixedABIFunctionInfo;
89 
90     // TODO: Pick a high register, and shift down, similar to a kernel.
91     FrameOffsetReg = AMDGPU::SGPR33;
92     StackPtrOffsetReg = AMDGPU::SGPR32;
93 
94     if (!ST.enableFlatScratch()) {
95       // Non-entry functions have no special inputs for now, other registers
96       // required for scratch access.
97       ScratchRSrcReg = AMDGPU::SGPR0_SGPR1_SGPR2_SGPR3;
98 
99       ArgInfo.PrivateSegmentBuffer =
100         ArgDescriptor::createRegister(ScratchRSrcReg);
101     }
102 
103     if (!F.hasFnAttribute("amdgpu-no-implicitarg-ptr"))
104       ImplicitArgPtr = true;
105   } else {
106     ImplicitArgPtr = false;
107     MaxKernArgAlign = std::max(ST.getAlignmentForImplicitArgPtr(),
108                                MaxKernArgAlign);
109 
110     if (ST.hasGFX90AInsts() &&
111         ST.getMaxNumVGPRs(F) <= AMDGPU::VGPR_32RegClass.getNumRegs() &&
112         !mayUseAGPRs(F))
113       MayNeedAGPRs = false; // We will select all MAI with VGPR operands.
114   }
115 
116   bool isAmdHsaOrMesa = ST.isAmdHsaOrMesa(F);
117   if (isAmdHsaOrMesa && !ST.enableFlatScratch())
118     PrivateSegmentBuffer = true;
119   else if (ST.isMesaGfxShader(F))
120     ImplicitBufferPtr = true;
121 
122   if (!AMDGPU::isGraphics(CC)) {
123     if (IsKernel || !F.hasFnAttribute("amdgpu-no-workgroup-id-x"))
124       WorkGroupIDX = true;
125 
126     if (!F.hasFnAttribute("amdgpu-no-workgroup-id-y"))
127       WorkGroupIDY = true;
128 
129     if (!F.hasFnAttribute("amdgpu-no-workgroup-id-z"))
130       WorkGroupIDZ = true;
131 
132     if (IsKernel || !F.hasFnAttribute("amdgpu-no-workitem-id-x"))
133       WorkItemIDX = true;
134 
135     if (!F.hasFnAttribute("amdgpu-no-workitem-id-y") &&
136         ST.getMaxWorkitemID(F, 1) != 0)
137       WorkItemIDY = true;
138 
139     if (!F.hasFnAttribute("amdgpu-no-workitem-id-z") &&
140         ST.getMaxWorkitemID(F, 2) != 0)
141       WorkItemIDZ = true;
142 
143     if (!F.hasFnAttribute("amdgpu-no-dispatch-ptr"))
144       DispatchPtr = true;
145 
146     if (!F.hasFnAttribute("amdgpu-no-queue-ptr"))
147       QueuePtr = true;
148 
149     if (!F.hasFnAttribute("amdgpu-no-dispatch-id"))
150       DispatchID = true;
151 
152     if (!IsKernel && !F.hasFnAttribute("amdgpu-no-lds-kernel-id"))
153       LDSKernelId = true;
154   }
155 
156   // FIXME: This attribute is a hack, we just need an analysis on the function
157   // to look for allocas.
158   bool HasStackObjects = F.hasFnAttribute("amdgpu-stack-objects");
159 
160   // TODO: This could be refined a lot. The attribute is a poor way of
161   // detecting calls or stack objects that may require it before argument
162   // lowering.
163   if (ST.hasFlatAddressSpace() && isEntryFunction() &&
164       (isAmdHsaOrMesa || ST.enableFlatScratch()) &&
165       (HasCalls || HasStackObjects || ST.enableFlatScratch()) &&
166       !ST.flatScratchIsArchitected()) {
167     FlatScratchInit = true;
168   }
169 
170   if (isEntryFunction()) {
171     // X, XY, and XYZ are the only supported combinations, so make sure Y is
172     // enabled if Z is.
173     if (WorkItemIDZ)
174       WorkItemIDY = true;
175 
176     if (!ST.flatScratchIsArchitected()) {
177       PrivateSegmentWaveByteOffset = true;
178 
179       // HS and GS always have the scratch wave offset in SGPR5 on GFX9.
180       if (ST.getGeneration() >= AMDGPUSubtarget::GFX9 &&
181           (CC == CallingConv::AMDGPU_HS || CC == CallingConv::AMDGPU_GS))
182         ArgInfo.PrivateSegmentWaveByteOffset =
183             ArgDescriptor::createRegister(AMDGPU::SGPR5);
184     }
185   }
186 
187   Attribute A = F.getFnAttribute("amdgpu-git-ptr-high");
188   StringRef S = A.getValueAsString();
189   if (!S.empty())
190     S.consumeInteger(0, GITPtrHigh);
191 
192   A = F.getFnAttribute("amdgpu-32bit-address-high-bits");
193   S = A.getValueAsString();
194   if (!S.empty())
195     S.consumeInteger(0, HighBitsOf32BitAddress);
196 
197   // On GFX908, in order to guarantee copying between AGPRs, we need a scratch
198   // VGPR available at all times. For now, reserve highest available VGPR. After
199   // RA, shift it to the lowest available unused VGPR if the one exist.
200   if (ST.hasMAIInsts() && !ST.hasGFX90AInsts()) {
201     VGPRForAGPRCopy =
202         AMDGPU::VGPR_32RegClass.getRegister(ST.getMaxNumVGPRs(F) - 1);
203   }
204 }
205 
206 MachineFunctionInfo *SIMachineFunctionInfo::clone(
207     BumpPtrAllocator &Allocator, MachineFunction &DestMF,
208     const DenseMap<MachineBasicBlock *, MachineBasicBlock *> &Src2DstMBB)
209     const {
210   return DestMF.cloneInfo<SIMachineFunctionInfo>(*this);
211 }
212 
213 void SIMachineFunctionInfo::limitOccupancy(const MachineFunction &MF) {
214   limitOccupancy(getMaxWavesPerEU());
215   const GCNSubtarget& ST = MF.getSubtarget<GCNSubtarget>();
216   limitOccupancy(ST.getOccupancyWithLocalMemSize(getLDSSize(),
217                  MF.getFunction()));
218 }
219 
220 Register SIMachineFunctionInfo::addPrivateSegmentBuffer(
221   const SIRegisterInfo &TRI) {
222   ArgInfo.PrivateSegmentBuffer =
223     ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
224     getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SGPR_128RegClass));
225   NumUserSGPRs += 4;
226   return ArgInfo.PrivateSegmentBuffer.getRegister();
227 }
228 
229 Register SIMachineFunctionInfo::addDispatchPtr(const SIRegisterInfo &TRI) {
230   ArgInfo.DispatchPtr = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
231     getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
232   NumUserSGPRs += 2;
233   return ArgInfo.DispatchPtr.getRegister();
234 }
235 
236 Register SIMachineFunctionInfo::addQueuePtr(const SIRegisterInfo &TRI) {
237   ArgInfo.QueuePtr = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
238     getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
239   NumUserSGPRs += 2;
240   return ArgInfo.QueuePtr.getRegister();
241 }
242 
243 Register SIMachineFunctionInfo::addKernargSegmentPtr(const SIRegisterInfo &TRI) {
244   ArgInfo.KernargSegmentPtr
245     = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
246     getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
247   NumUserSGPRs += 2;
248   return ArgInfo.KernargSegmentPtr.getRegister();
249 }
250 
251 Register SIMachineFunctionInfo::addDispatchID(const SIRegisterInfo &TRI) {
252   ArgInfo.DispatchID = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
253     getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
254   NumUserSGPRs += 2;
255   return ArgInfo.DispatchID.getRegister();
256 }
257 
258 Register SIMachineFunctionInfo::addFlatScratchInit(const SIRegisterInfo &TRI) {
259   ArgInfo.FlatScratchInit = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
260     getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
261   NumUserSGPRs += 2;
262   return ArgInfo.FlatScratchInit.getRegister();
263 }
264 
265 Register SIMachineFunctionInfo::addImplicitBufferPtr(const SIRegisterInfo &TRI) {
266   ArgInfo.ImplicitBufferPtr = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
267     getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
268   NumUserSGPRs += 2;
269   return ArgInfo.ImplicitBufferPtr.getRegister();
270 }
271 
272 Register SIMachineFunctionInfo::addLDSKernelId() {
273   ArgInfo.LDSKernelId = ArgDescriptor::createRegister(getNextUserSGPR());
274   NumUserSGPRs += 1;
275   return ArgInfo.LDSKernelId.getRegister();
276 }
277 
278 void SIMachineFunctionInfo::allocateWWMSpill(MachineFunction &MF, Register VGPR,
279                                              uint64_t Size, Align Alignment) {
280   // Skip if it is an entry function or the register is already added.
281   if (isEntryFunction() || WWMSpills.count(VGPR))
282     return;
283 
284   WWMSpills.insert(std::make_pair(
285       VGPR, MF.getFrameInfo().CreateSpillStackObject(Size, Alignment)));
286 }
287 
288 // Separate out the callee-saved and scratch registers.
289 void SIMachineFunctionInfo::splitWWMSpillRegisters(
290     MachineFunction &MF,
291     SmallVectorImpl<std::pair<Register, int>> &CalleeSavedRegs,
292     SmallVectorImpl<std::pair<Register, int>> &ScratchRegs) const {
293   const MCPhysReg *CSRegs = MF.getRegInfo().getCalleeSavedRegs();
294   for (auto &Reg : WWMSpills) {
295     if (isCalleeSavedReg(CSRegs, Reg.first))
296       CalleeSavedRegs.push_back(Reg);
297     else
298       ScratchRegs.push_back(Reg);
299   }
300 }
301 
302 bool SIMachineFunctionInfo::isCalleeSavedReg(const MCPhysReg *CSRegs,
303                                              MCPhysReg Reg) const {
304   for (unsigned I = 0; CSRegs[I]; ++I) {
305     if (CSRegs[I] == Reg)
306       return true;
307   }
308 
309   return false;
310 }
311 
312 bool SIMachineFunctionInfo::allocateVGPRForSGPRSpills(MachineFunction &MF,
313                                                       int FI,
314                                                       unsigned LaneIndex) {
315   const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
316   const SIRegisterInfo *TRI = ST.getRegisterInfo();
317   MachineRegisterInfo &MRI = MF.getRegInfo();
318   Register LaneVGPR;
319   if (!LaneIndex) {
320     LaneVGPR = TRI->findUnusedRegister(MRI, &AMDGPU::VGPR_32RegClass, MF);
321     if (LaneVGPR == AMDGPU::NoRegister) {
322       // We have no VGPRs left for spilling SGPRs. Reset because we will not
323       // partially spill the SGPR to VGPRs.
324       SGPRSpillToVGPRLanes.erase(FI);
325       return false;
326     }
327 
328     SpillVGPRs.push_back(LaneVGPR);
329     // Add this register as live-in to all blocks to avoid machine verifier
330     // complaining about use of an undefined physical register.
331     for (MachineBasicBlock &BB : MF)
332       BB.addLiveIn(LaneVGPR);
333   } else {
334     LaneVGPR = SpillVGPRs.back();
335   }
336 
337   SGPRSpillToVGPRLanes[FI].push_back(
338       SIRegisterInfo::SpilledReg(LaneVGPR, LaneIndex));
339   return true;
340 }
341 
342 bool SIMachineFunctionInfo::allocateVGPRForPrologEpilogSGPRSpills(
343     MachineFunction &MF, int FI, unsigned LaneIndex) {
344   const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
345   const SIRegisterInfo *TRI = ST.getRegisterInfo();
346   MachineRegisterInfo &MRI = MF.getRegInfo();
347   Register LaneVGPR;
348   if (!LaneIndex) {
349     LaneVGPR = TRI->findUnusedRegister(MRI, &AMDGPU::VGPR_32RegClass, MF);
350     if (LaneVGPR == AMDGPU::NoRegister) {
351       // We have no VGPRs left for spilling SGPRs. Reset because we will not
352       // partially spill the SGPR to VGPRs.
353       PrologEpilogSGPRSpillToVGPRLanes.erase(FI);
354       return false;
355     }
356 
357     allocateWWMSpill(MF, LaneVGPR);
358   } else {
359     LaneVGPR = WWMSpills.back().first;
360   }
361 
362   PrologEpilogSGPRSpillToVGPRLanes[FI].push_back(
363       SIRegisterInfo::SpilledReg(LaneVGPR, LaneIndex));
364   return true;
365 }
366 
367 bool SIMachineFunctionInfo::allocateSGPRSpillToVGPRLane(MachineFunction &MF,
368                                                         int FI,
369                                                         bool IsPrologEpilog) {
370   std::vector<SIRegisterInfo::SpilledReg> &SpillLanes =
371       IsPrologEpilog ? PrologEpilogSGPRSpillToVGPRLanes[FI]
372                      : SGPRSpillToVGPRLanes[FI];
373 
374   // This has already been allocated.
375   if (!SpillLanes.empty())
376     return true;
377 
378   const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
379   MachineFrameInfo &FrameInfo = MF.getFrameInfo();
380   unsigned WaveSize = ST.getWavefrontSize();
381 
382   unsigned Size = FrameInfo.getObjectSize(FI);
383   unsigned NumLanes = Size / 4;
384 
385   if (NumLanes > WaveSize)
386     return false;
387 
388   assert(Size >= 4 && "invalid sgpr spill size");
389   assert(ST.getRegisterInfo()->spillSGPRToVGPR() &&
390          "not spilling SGPRs to VGPRs");
391 
392   unsigned &NumSpillLanes =
393       IsPrologEpilog ? NumVGPRPrologEpilogSpillLanes : NumVGPRSpillLanes;
394 
395   for (unsigned I = 0; I < NumLanes; ++I, ++NumSpillLanes) {
396     unsigned LaneIndex = (NumSpillLanes % WaveSize);
397 
398     bool Allocated =
399         IsPrologEpilog
400             ? allocateVGPRForPrologEpilogSGPRSpills(MF, FI, LaneIndex)
401             : allocateVGPRForSGPRSpills(MF, FI, LaneIndex);
402     if (!Allocated) {
403       NumSpillLanes -= I;
404       return false;
405     }
406   }
407 
408   return true;
409 }
410 
411 /// Reserve AGPRs or VGPRs to support spilling for FrameIndex \p FI.
412 /// Either AGPR is spilled to VGPR to vice versa.
413 /// Returns true if a \p FI can be eliminated completely.
414 bool SIMachineFunctionInfo::allocateVGPRSpillToAGPR(MachineFunction &MF,
415                                                     int FI,
416                                                     bool isAGPRtoVGPR) {
417   MachineRegisterInfo &MRI = MF.getRegInfo();
418   MachineFrameInfo &FrameInfo = MF.getFrameInfo();
419   const GCNSubtarget &ST =  MF.getSubtarget<GCNSubtarget>();
420 
421   assert(ST.hasMAIInsts() && FrameInfo.isSpillSlotObjectIndex(FI));
422 
423   auto &Spill = VGPRToAGPRSpills[FI];
424 
425   // This has already been allocated.
426   if (!Spill.Lanes.empty())
427     return Spill.FullyAllocated;
428 
429   unsigned Size = FrameInfo.getObjectSize(FI);
430   unsigned NumLanes = Size / 4;
431   Spill.Lanes.resize(NumLanes, AMDGPU::NoRegister);
432 
433   const TargetRegisterClass &RC =
434       isAGPRtoVGPR ? AMDGPU::VGPR_32RegClass : AMDGPU::AGPR_32RegClass;
435   auto Regs = RC.getRegisters();
436 
437   auto &SpillRegs = isAGPRtoVGPR ? SpillAGPR : SpillVGPR;
438   const SIRegisterInfo *TRI = ST.getRegisterInfo();
439   Spill.FullyAllocated = true;
440 
441   // FIXME: Move allocation logic out of MachineFunctionInfo and initialize
442   // once.
443   BitVector OtherUsedRegs;
444   OtherUsedRegs.resize(TRI->getNumRegs());
445 
446   const uint32_t *CSRMask =
447       TRI->getCallPreservedMask(MF, MF.getFunction().getCallingConv());
448   if (CSRMask)
449     OtherUsedRegs.setBitsInMask(CSRMask);
450 
451   // TODO: Should include register tuples, but doesn't matter with current
452   // usage.
453   for (MCPhysReg Reg : SpillAGPR)
454     OtherUsedRegs.set(Reg);
455   for (MCPhysReg Reg : SpillVGPR)
456     OtherUsedRegs.set(Reg);
457 
458   SmallVectorImpl<MCPhysReg>::const_iterator NextSpillReg = Regs.begin();
459   for (int I = NumLanes - 1; I >= 0; --I) {
460     NextSpillReg = std::find_if(
461         NextSpillReg, Regs.end(), [&MRI, &OtherUsedRegs](MCPhysReg Reg) {
462           return MRI.isAllocatable(Reg) && !MRI.isPhysRegUsed(Reg) &&
463                  !OtherUsedRegs[Reg];
464         });
465 
466     if (NextSpillReg == Regs.end()) { // Registers exhausted
467       Spill.FullyAllocated = false;
468       break;
469     }
470 
471     OtherUsedRegs.set(*NextSpillReg);
472     SpillRegs.push_back(*NextSpillReg);
473     MRI.reserveReg(*NextSpillReg, TRI);
474     Spill.Lanes[I] = *NextSpillReg++;
475   }
476 
477   return Spill.FullyAllocated;
478 }
479 
480 bool SIMachineFunctionInfo::removeDeadFrameIndices(
481     MachineFrameInfo &MFI, bool ResetSGPRSpillStackIDs) {
482   // Remove dead frame indices from function frame. And also make sure to remove
483   // the frame indices from `SGPRSpillToVGPRLanes` data structure, otherwise, it
484   // could result in an unexpected side effect and bug, in case of any
485   // re-mapping of freed frame indices by later pass(es) like "stack slot
486   // coloring".
487   for (auto &R : make_early_inc_range(SGPRSpillToVGPRLanes)) {
488     MFI.RemoveStackObject(R.first);
489     SGPRSpillToVGPRLanes.erase(R.first);
490   }
491 
492   bool HaveSGPRToMemory = false;
493 
494   if (ResetSGPRSpillStackIDs) {
495     // All other SGPRs must be allocated on the default stack, so reset the
496     // stack ID.
497     for (int I = MFI.getObjectIndexBegin(), E = MFI.getObjectIndexEnd(); I != E;
498          ++I) {
499       if (!checkIndexInPrologEpilogSGPRSpills(I)) {
500         if (MFI.getStackID(I) == TargetStackID::SGPRSpill) {
501           MFI.setStackID(I, TargetStackID::Default);
502           HaveSGPRToMemory = true;
503         }
504       }
505     }
506   }
507 
508   for (auto &R : VGPRToAGPRSpills) {
509     if (R.second.IsDead)
510       MFI.RemoveStackObject(R.first);
511   }
512 
513   return HaveSGPRToMemory;
514 }
515 
516 int SIMachineFunctionInfo::getScavengeFI(MachineFrameInfo &MFI,
517                                          const SIRegisterInfo &TRI) {
518   if (ScavengeFI)
519     return *ScavengeFI;
520   if (isEntryFunction()) {
521     ScavengeFI = MFI.CreateFixedObject(
522         TRI.getSpillSize(AMDGPU::SGPR_32RegClass), 0, false);
523   } else {
524     ScavengeFI = MFI.CreateStackObject(
525         TRI.getSpillSize(AMDGPU::SGPR_32RegClass),
526         TRI.getSpillAlign(AMDGPU::SGPR_32RegClass), false);
527   }
528   return *ScavengeFI;
529 }
530 
531 MCPhysReg SIMachineFunctionInfo::getNextUserSGPR() const {
532   assert(NumSystemSGPRs == 0 && "System SGPRs must be added after user SGPRs");
533   return AMDGPU::SGPR0 + NumUserSGPRs;
534 }
535 
536 MCPhysReg SIMachineFunctionInfo::getNextSystemSGPR() const {
537   return AMDGPU::SGPR0 + NumUserSGPRs + NumSystemSGPRs;
538 }
539 
540 Register
541 SIMachineFunctionInfo::getGITPtrLoReg(const MachineFunction &MF) const {
542   const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
543   if (!ST.isAmdPalOS())
544     return Register();
545   Register GitPtrLo = AMDGPU::SGPR0; // Low GIT address passed in
546   if (ST.hasMergedShaders()) {
547     switch (MF.getFunction().getCallingConv()) {
548     case CallingConv::AMDGPU_HS:
549     case CallingConv::AMDGPU_GS:
550       // Low GIT address is passed in s8 rather than s0 for an LS+HS or
551       // ES+GS merged shader on gfx9+.
552       GitPtrLo = AMDGPU::SGPR8;
553       return GitPtrLo;
554     default:
555       return GitPtrLo;
556     }
557   }
558   return GitPtrLo;
559 }
560 
561 static yaml::StringValue regToString(Register Reg,
562                                      const TargetRegisterInfo &TRI) {
563   yaml::StringValue Dest;
564   {
565     raw_string_ostream OS(Dest.Value);
566     OS << printReg(Reg, &TRI);
567   }
568   return Dest;
569 }
570 
571 static std::optional<yaml::SIArgumentInfo>
572 convertArgumentInfo(const AMDGPUFunctionArgInfo &ArgInfo,
573                     const TargetRegisterInfo &TRI) {
574   yaml::SIArgumentInfo AI;
575 
576   auto convertArg = [&](std::optional<yaml::SIArgument> &A,
577                         const ArgDescriptor &Arg) {
578     if (!Arg)
579       return false;
580 
581     // Create a register or stack argument.
582     yaml::SIArgument SA = yaml::SIArgument::createArgument(Arg.isRegister());
583     if (Arg.isRegister()) {
584       raw_string_ostream OS(SA.RegisterName.Value);
585       OS << printReg(Arg.getRegister(), &TRI);
586     } else
587       SA.StackOffset = Arg.getStackOffset();
588     // Check and update the optional mask.
589     if (Arg.isMasked())
590       SA.Mask = Arg.getMask();
591 
592     A = SA;
593     return true;
594   };
595 
596   bool Any = false;
597   Any |= convertArg(AI.PrivateSegmentBuffer, ArgInfo.PrivateSegmentBuffer);
598   Any |= convertArg(AI.DispatchPtr, ArgInfo.DispatchPtr);
599   Any |= convertArg(AI.QueuePtr, ArgInfo.QueuePtr);
600   Any |= convertArg(AI.KernargSegmentPtr, ArgInfo.KernargSegmentPtr);
601   Any |= convertArg(AI.DispatchID, ArgInfo.DispatchID);
602   Any |= convertArg(AI.FlatScratchInit, ArgInfo.FlatScratchInit);
603   Any |= convertArg(AI.LDSKernelId, ArgInfo.LDSKernelId);
604   Any |= convertArg(AI.PrivateSegmentSize, ArgInfo.PrivateSegmentSize);
605   Any |= convertArg(AI.WorkGroupIDX, ArgInfo.WorkGroupIDX);
606   Any |= convertArg(AI.WorkGroupIDY, ArgInfo.WorkGroupIDY);
607   Any |= convertArg(AI.WorkGroupIDZ, ArgInfo.WorkGroupIDZ);
608   Any |= convertArg(AI.WorkGroupInfo, ArgInfo.WorkGroupInfo);
609   Any |= convertArg(AI.PrivateSegmentWaveByteOffset,
610                     ArgInfo.PrivateSegmentWaveByteOffset);
611   Any |= convertArg(AI.ImplicitArgPtr, ArgInfo.ImplicitArgPtr);
612   Any |= convertArg(AI.ImplicitBufferPtr, ArgInfo.ImplicitBufferPtr);
613   Any |= convertArg(AI.WorkItemIDX, ArgInfo.WorkItemIDX);
614   Any |= convertArg(AI.WorkItemIDY, ArgInfo.WorkItemIDY);
615   Any |= convertArg(AI.WorkItemIDZ, ArgInfo.WorkItemIDZ);
616 
617   if (Any)
618     return AI;
619 
620   return std::nullopt;
621 }
622 
623 yaml::SIMachineFunctionInfo::SIMachineFunctionInfo(
624     const llvm::SIMachineFunctionInfo &MFI, const TargetRegisterInfo &TRI,
625     const llvm::MachineFunction &MF)
626     : ExplicitKernArgSize(MFI.getExplicitKernArgSize()),
627       MaxKernArgAlign(MFI.getMaxKernArgAlign()), LDSSize(MFI.getLDSSize()),
628       GDSSize(MFI.getGDSSize()),
629       DynLDSAlign(MFI.getDynLDSAlign()), IsEntryFunction(MFI.isEntryFunction()),
630       NoSignedZerosFPMath(MFI.hasNoSignedZerosFPMath()),
631       MemoryBound(MFI.isMemoryBound()), WaveLimiter(MFI.needsWaveLimiter()),
632       HasSpilledSGPRs(MFI.hasSpilledSGPRs()),
633       HasSpilledVGPRs(MFI.hasSpilledVGPRs()),
634       HighBitsOf32BitAddress(MFI.get32BitAddressHighBits()),
635       Occupancy(MFI.getOccupancy()),
636       ScratchRSrcReg(regToString(MFI.getScratchRSrcReg(), TRI)),
637       FrameOffsetReg(regToString(MFI.getFrameOffsetReg(), TRI)),
638       StackPtrOffsetReg(regToString(MFI.getStackPtrOffsetReg(), TRI)),
639       BytesInStackArgArea(MFI.getBytesInStackArgArea()),
640       ReturnsVoid(MFI.returnsVoid()),
641       ArgInfo(convertArgumentInfo(MFI.getArgInfo(), TRI)), Mode(MFI.getMode()) {
642   for (Register Reg : MFI.getWWMReservedRegs())
643     WWMReservedRegs.push_back(regToString(Reg, TRI));
644 
645   if (MFI.getVGPRForAGPRCopy())
646     VGPRForAGPRCopy = regToString(MFI.getVGPRForAGPRCopy(), TRI);
647   auto SFI = MFI.getOptionalScavengeFI();
648   if (SFI)
649     ScavengeFI = yaml::FrameIndex(*SFI, MF.getFrameInfo());
650 }
651 
652 void yaml::SIMachineFunctionInfo::mappingImpl(yaml::IO &YamlIO) {
653   MappingTraits<SIMachineFunctionInfo>::mapping(YamlIO, *this);
654 }
655 
656 bool SIMachineFunctionInfo::initializeBaseYamlFields(
657     const yaml::SIMachineFunctionInfo &YamlMFI, const MachineFunction &MF,
658     PerFunctionMIParsingState &PFS, SMDiagnostic &Error, SMRange &SourceRange) {
659   ExplicitKernArgSize = YamlMFI.ExplicitKernArgSize;
660   MaxKernArgAlign = YamlMFI.MaxKernArgAlign;
661   LDSSize = YamlMFI.LDSSize;
662   GDSSize = YamlMFI.GDSSize;
663   DynLDSAlign = YamlMFI.DynLDSAlign;
664   HighBitsOf32BitAddress = YamlMFI.HighBitsOf32BitAddress;
665   Occupancy = YamlMFI.Occupancy;
666   IsEntryFunction = YamlMFI.IsEntryFunction;
667   NoSignedZerosFPMath = YamlMFI.NoSignedZerosFPMath;
668   MemoryBound = YamlMFI.MemoryBound;
669   WaveLimiter = YamlMFI.WaveLimiter;
670   HasSpilledSGPRs = YamlMFI.HasSpilledSGPRs;
671   HasSpilledVGPRs = YamlMFI.HasSpilledVGPRs;
672   BytesInStackArgArea = YamlMFI.BytesInStackArgArea;
673   ReturnsVoid = YamlMFI.ReturnsVoid;
674 
675   if (YamlMFI.ScavengeFI) {
676     auto FIOrErr = YamlMFI.ScavengeFI->getFI(MF.getFrameInfo());
677     if (!FIOrErr) {
678       // Create a diagnostic for a the frame index.
679       const MemoryBuffer &Buffer =
680           *PFS.SM->getMemoryBuffer(PFS.SM->getMainFileID());
681 
682       Error = SMDiagnostic(*PFS.SM, SMLoc(), Buffer.getBufferIdentifier(), 1, 1,
683                            SourceMgr::DK_Error, toString(FIOrErr.takeError()),
684                            "", std::nullopt, std::nullopt);
685       SourceRange = YamlMFI.ScavengeFI->SourceRange;
686       return true;
687     }
688     ScavengeFI = *FIOrErr;
689   } else {
690     ScavengeFI = std::nullopt;
691   }
692   return false;
693 }
694 
695 bool SIMachineFunctionInfo::mayUseAGPRs(const Function &F) const {
696   for (const BasicBlock &BB : F) {
697     for (const Instruction &I : BB) {
698       const auto *CB = dyn_cast<CallBase>(&I);
699       if (!CB)
700         continue;
701 
702       if (CB->isInlineAsm()) {
703         const InlineAsm *IA = dyn_cast<InlineAsm>(CB->getCalledOperand());
704         for (const auto &CI : IA->ParseConstraints()) {
705           for (StringRef Code : CI.Codes) {
706             Code.consume_front("{");
707             if (Code.startswith("a"))
708               return true;
709           }
710         }
711         continue;
712       }
713 
714       const Function *Callee =
715           dyn_cast<Function>(CB->getCalledOperand()->stripPointerCasts());
716       if (!Callee)
717         return true;
718 
719       if (Callee->getIntrinsicID() == Intrinsic::not_intrinsic)
720         return true;
721     }
722   }
723 
724   return false;
725 }
726 
727 bool SIMachineFunctionInfo::usesAGPRs(const MachineFunction &MF) const {
728   if (UsesAGPRs)
729     return *UsesAGPRs;
730 
731   if (!mayNeedAGPRs()) {
732     UsesAGPRs = false;
733     return false;
734   }
735 
736   if (!AMDGPU::isEntryFunctionCC(MF.getFunction().getCallingConv()) ||
737       MF.getFrameInfo().hasCalls()) {
738     UsesAGPRs = true;
739     return true;
740   }
741 
742   const MachineRegisterInfo &MRI = MF.getRegInfo();
743 
744   for (unsigned I = 0, E = MRI.getNumVirtRegs(); I != E; ++I) {
745     const Register Reg = Register::index2VirtReg(I);
746     const TargetRegisterClass *RC = MRI.getRegClassOrNull(Reg);
747     if (RC && SIRegisterInfo::isAGPRClass(RC)) {
748       UsesAGPRs = true;
749       return true;
750     } else if (!RC && !MRI.use_empty(Reg) && MRI.getType(Reg).isValid()) {
751       // Defer caching UsesAGPRs, function might not yet been regbank selected.
752       return true;
753     }
754   }
755 
756   for (MCRegister Reg : AMDGPU::AGPR_32RegClass) {
757     if (MRI.isPhysRegUsed(Reg)) {
758       UsesAGPRs = true;
759       return true;
760     }
761   }
762 
763   UsesAGPRs = false;
764   return false;
765 }
766