[Alignment] Migrate Attribute::getWith(Stack)Alignment
[llvm-core.git] / lib / Target / AMDGPU / SIMachineFunctionInfo.cpp
blob7dd0f11c95ded40f2eb74dc48b65b00bec65fc65
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 //===----------------------------------------------------------------------===//
9 #include "SIMachineFunctionInfo.h"
10 #include "AMDGPUArgumentUsageInfo.h"
11 #include "AMDGPUSubtarget.h"
12 #include "SIRegisterInfo.h"
13 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
14 #include "Utils/AMDGPUBaseInfo.h"
15 #include "llvm/ADT/Optional.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/IR/CallingConv.h"
21 #include "llvm/IR/Function.h"
22 #include <cassert>
23 #include <vector>
25 #define MAX_LANES 64
27 using namespace llvm;
29 SIMachineFunctionInfo::SIMachineFunctionInfo(const MachineFunction &MF)
30 : AMDGPUMachineFunction(MF),
31 Mode(MF.getFunction()),
32 PrivateSegmentBuffer(false),
33 DispatchPtr(false),
34 QueuePtr(false),
35 KernargSegmentPtr(false),
36 DispatchID(false),
37 FlatScratchInit(false),
38 WorkGroupIDX(false),
39 WorkGroupIDY(false),
40 WorkGroupIDZ(false),
41 WorkGroupInfo(false),
42 PrivateSegmentWaveByteOffset(false),
43 WorkItemIDX(false),
44 WorkItemIDY(false),
45 WorkItemIDZ(false),
46 ImplicitBufferPtr(false),
47 ImplicitArgPtr(false),
48 GITPtrHigh(0xffffffff),
49 HighBitsOf32BitAddress(0),
50 GDSSize(0) {
51 const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
52 const Function &F = MF.getFunction();
53 FlatWorkGroupSizes = ST.getFlatWorkGroupSizes(F);
54 WavesPerEU = ST.getWavesPerEU(F);
56 Occupancy = ST.computeOccupancy(MF, getLDSSize());
57 CallingConv::ID CC = F.getCallingConv();
59 if (CC == CallingConv::AMDGPU_KERNEL || CC == CallingConv::SPIR_KERNEL) {
60 if (!F.arg_empty())
61 KernargSegmentPtr = true;
62 WorkGroupIDX = true;
63 WorkItemIDX = true;
64 } else if (CC == CallingConv::AMDGPU_PS) {
65 PSInputAddr = AMDGPU::getInitialPSInputAddr(F);
68 if (!isEntryFunction()) {
69 // Non-entry functions have no special inputs for now, other registers
70 // required for scratch access.
71 ScratchRSrcReg = AMDGPU::SGPR0_SGPR1_SGPR2_SGPR3;
72 ScratchWaveOffsetReg = AMDGPU::SGPR33;
74 // TODO: Pick a high register, and shift down, similar to a kernel.
75 FrameOffsetReg = AMDGPU::SGPR34;
76 StackPtrOffsetReg = AMDGPU::SGPR32;
78 ArgInfo.PrivateSegmentBuffer =
79 ArgDescriptor::createRegister(ScratchRSrcReg);
80 ArgInfo.PrivateSegmentWaveByteOffset =
81 ArgDescriptor::createRegister(ScratchWaveOffsetReg);
83 if (F.hasFnAttribute("amdgpu-implicitarg-ptr"))
84 ImplicitArgPtr = true;
85 } else {
86 if (F.hasFnAttribute("amdgpu-implicitarg-ptr")) {
87 KernargSegmentPtr = true;
88 MaxKernArgAlign = std::max(ST.getAlignmentForImplicitArgPtr(),
89 MaxKernArgAlign);
93 if (F.hasFnAttribute("amdgpu-work-group-id-x"))
94 WorkGroupIDX = true;
96 if (F.hasFnAttribute("amdgpu-work-group-id-y"))
97 WorkGroupIDY = true;
99 if (F.hasFnAttribute("amdgpu-work-group-id-z"))
100 WorkGroupIDZ = true;
102 if (F.hasFnAttribute("amdgpu-work-item-id-x"))
103 WorkItemIDX = true;
105 if (F.hasFnAttribute("amdgpu-work-item-id-y"))
106 WorkItemIDY = true;
108 if (F.hasFnAttribute("amdgpu-work-item-id-z"))
109 WorkItemIDZ = true;
111 const MachineFrameInfo &FrameInfo = MF.getFrameInfo();
112 bool HasStackObjects = FrameInfo.hasStackObjects();
114 if (isEntryFunction()) {
115 // X, XY, and XYZ are the only supported combinations, so make sure Y is
116 // enabled if Z is.
117 if (WorkItemIDZ)
118 WorkItemIDY = true;
120 PrivateSegmentWaveByteOffset = true;
122 // HS and GS always have the scratch wave offset in SGPR5 on GFX9.
123 if (ST.getGeneration() >= AMDGPUSubtarget::GFX9 &&
124 (CC == CallingConv::AMDGPU_HS || CC == CallingConv::AMDGPU_GS))
125 ArgInfo.PrivateSegmentWaveByteOffset =
126 ArgDescriptor::createRegister(AMDGPU::SGPR5);
129 bool isAmdHsaOrMesa = ST.isAmdHsaOrMesa(F);
130 if (isAmdHsaOrMesa) {
131 PrivateSegmentBuffer = true;
133 if (F.hasFnAttribute("amdgpu-dispatch-ptr"))
134 DispatchPtr = true;
136 if (F.hasFnAttribute("amdgpu-queue-ptr"))
137 QueuePtr = true;
139 if (F.hasFnAttribute("amdgpu-dispatch-id"))
140 DispatchID = true;
141 } else if (ST.isMesaGfxShader(F)) {
142 ImplicitBufferPtr = true;
145 if (F.hasFnAttribute("amdgpu-kernarg-segment-ptr"))
146 KernargSegmentPtr = true;
148 if (ST.hasFlatAddressSpace() && isEntryFunction() && isAmdHsaOrMesa) {
149 auto hasNonSpillStackObjects = [&]() {
150 // Avoid expensive checking if there's no stack objects.
151 if (!HasStackObjects)
152 return false;
153 for (auto OI = FrameInfo.getObjectIndexBegin(),
154 OE = FrameInfo.getObjectIndexEnd(); OI != OE; ++OI)
155 if (!FrameInfo.isSpillSlotObjectIndex(OI))
156 return true;
157 // All stack objects are spill slots.
158 return false;
160 // TODO: This could be refined a lot. The attribute is a poor way of
161 // detecting calls that may require it before argument lowering.
162 if (hasNonSpillStackObjects() || F.hasFnAttribute("amdgpu-flat-scratch"))
163 FlatScratchInit = true;
166 Attribute A = F.getFnAttribute("amdgpu-git-ptr-high");
167 StringRef S = A.getValueAsString();
168 if (!S.empty())
169 S.consumeInteger(0, GITPtrHigh);
171 A = F.getFnAttribute("amdgpu-32bit-address-high-bits");
172 S = A.getValueAsString();
173 if (!S.empty())
174 S.consumeInteger(0, HighBitsOf32BitAddress);
176 S = F.getFnAttribute("amdgpu-gds-size").getValueAsString();
177 if (!S.empty())
178 S.consumeInteger(0, GDSSize);
181 void SIMachineFunctionInfo::limitOccupancy(const MachineFunction &MF) {
182 limitOccupancy(getMaxWavesPerEU());
183 const GCNSubtarget& ST = MF.getSubtarget<GCNSubtarget>();
184 limitOccupancy(ST.getOccupancyWithLocalMemSize(getLDSSize(),
185 MF.getFunction()));
188 unsigned SIMachineFunctionInfo::addPrivateSegmentBuffer(
189 const SIRegisterInfo &TRI) {
190 ArgInfo.PrivateSegmentBuffer =
191 ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
192 getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SGPR_128RegClass));
193 NumUserSGPRs += 4;
194 return ArgInfo.PrivateSegmentBuffer.getRegister();
197 unsigned SIMachineFunctionInfo::addDispatchPtr(const SIRegisterInfo &TRI) {
198 ArgInfo.DispatchPtr = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
199 getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
200 NumUserSGPRs += 2;
201 return ArgInfo.DispatchPtr.getRegister();
204 unsigned SIMachineFunctionInfo::addQueuePtr(const SIRegisterInfo &TRI) {
205 ArgInfo.QueuePtr = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
206 getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
207 NumUserSGPRs += 2;
208 return ArgInfo.QueuePtr.getRegister();
211 unsigned SIMachineFunctionInfo::addKernargSegmentPtr(const SIRegisterInfo &TRI) {
212 ArgInfo.KernargSegmentPtr
213 = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
214 getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
215 NumUserSGPRs += 2;
216 return ArgInfo.KernargSegmentPtr.getRegister();
219 unsigned SIMachineFunctionInfo::addDispatchID(const SIRegisterInfo &TRI) {
220 ArgInfo.DispatchID = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
221 getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
222 NumUserSGPRs += 2;
223 return ArgInfo.DispatchID.getRegister();
226 unsigned SIMachineFunctionInfo::addFlatScratchInit(const SIRegisterInfo &TRI) {
227 ArgInfo.FlatScratchInit = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
228 getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
229 NumUserSGPRs += 2;
230 return ArgInfo.FlatScratchInit.getRegister();
233 unsigned SIMachineFunctionInfo::addImplicitBufferPtr(const SIRegisterInfo &TRI) {
234 ArgInfo.ImplicitBufferPtr = ArgDescriptor::createRegister(TRI.getMatchingSuperReg(
235 getNextUserSGPR(), AMDGPU::sub0, &AMDGPU::SReg_64RegClass));
236 NumUserSGPRs += 2;
237 return ArgInfo.ImplicitBufferPtr.getRegister();
240 static bool isCalleeSavedReg(const MCPhysReg *CSRegs, MCPhysReg Reg) {
241 for (unsigned I = 0; CSRegs[I]; ++I) {
242 if (CSRegs[I] == Reg)
243 return true;
246 return false;
249 /// \p returns true if \p NumLanes slots are available in VGPRs already used for
250 /// SGPR spilling.
252 // FIXME: This only works after processFunctionBeforeFrameFinalized
253 bool SIMachineFunctionInfo::haveFreeLanesForSGPRSpill(const MachineFunction &MF,
254 unsigned NumNeed) const {
255 const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
256 unsigned WaveSize = ST.getWavefrontSize();
257 return NumVGPRSpillLanes + NumNeed <= WaveSize * SpillVGPRs.size();
260 /// Reserve a slice of a VGPR to support spilling for FrameIndex \p FI.
261 bool SIMachineFunctionInfo::allocateSGPRSpillToVGPR(MachineFunction &MF,
262 int FI) {
263 std::vector<SpilledReg> &SpillLanes = SGPRToVGPRSpills[FI];
265 // This has already been allocated.
266 if (!SpillLanes.empty())
267 return true;
269 const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
270 const SIRegisterInfo *TRI = ST.getRegisterInfo();
271 MachineFrameInfo &FrameInfo = MF.getFrameInfo();
272 MachineRegisterInfo &MRI = MF.getRegInfo();
273 unsigned WaveSize = ST.getWavefrontSize();
275 unsigned Size = FrameInfo.getObjectSize(FI);
276 assert(Size >= 4 && Size <= 64 && "invalid sgpr spill size");
277 assert(TRI->spillSGPRToVGPR() && "not spilling SGPRs to VGPRs");
279 int NumLanes = Size / 4;
281 const MCPhysReg *CSRegs = MRI.getCalleeSavedRegs();
283 // Make sure to handle the case where a wide SGPR spill may span between two
284 // VGPRs.
285 for (int I = 0; I < NumLanes; ++I, ++NumVGPRSpillLanes) {
286 unsigned LaneVGPR;
287 unsigned VGPRIndex = (NumVGPRSpillLanes % WaveSize);
289 if (VGPRIndex == 0) {
290 LaneVGPR = TRI->findUnusedRegister(MRI, &AMDGPU::VGPR_32RegClass, MF);
291 if (LaneVGPR == AMDGPU::NoRegister) {
292 // We have no VGPRs left for spilling SGPRs. Reset because we will not
293 // partially spill the SGPR to VGPRs.
294 SGPRToVGPRSpills.erase(FI);
295 NumVGPRSpillLanes -= I;
296 return false;
299 Optional<int> CSRSpillFI;
300 if ((FrameInfo.hasCalls() || !isEntryFunction()) && CSRegs &&
301 isCalleeSavedReg(CSRegs, LaneVGPR)) {
302 CSRSpillFI = FrameInfo.CreateSpillStackObject(4, 4);
305 SpillVGPRs.push_back(SGPRSpillVGPRCSR(LaneVGPR, CSRSpillFI));
307 // Add this register as live-in to all blocks to avoid machine verifer
308 // complaining about use of an undefined physical register.
309 for (MachineBasicBlock &BB : MF)
310 BB.addLiveIn(LaneVGPR);
311 } else {
312 LaneVGPR = SpillVGPRs.back().VGPR;
315 SpillLanes.push_back(SpilledReg(LaneVGPR, VGPRIndex));
318 return true;
321 /// Reserve AGPRs or VGPRs to support spilling for FrameIndex \p FI.
322 /// Either AGPR is spilled to VGPR to vice versa.
323 /// Returns true if a \p FI can be eliminated completely.
324 bool SIMachineFunctionInfo::allocateVGPRSpillToAGPR(MachineFunction &MF,
325 int FI,
326 bool isAGPRtoVGPR) {
327 MachineRegisterInfo &MRI = MF.getRegInfo();
328 MachineFrameInfo &FrameInfo = MF.getFrameInfo();
329 const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
331 assert(ST.hasMAIInsts() && FrameInfo.isSpillSlotObjectIndex(FI));
333 auto &Spill = VGPRToAGPRSpills[FI];
335 // This has already been allocated.
336 if (!Spill.Lanes.empty())
337 return Spill.FullyAllocated;
339 unsigned Size = FrameInfo.getObjectSize(FI);
340 unsigned NumLanes = Size / 4;
341 Spill.Lanes.resize(NumLanes, AMDGPU::NoRegister);
343 const TargetRegisterClass &RC =
344 isAGPRtoVGPR ? AMDGPU::VGPR_32RegClass : AMDGPU::AGPR_32RegClass;
345 auto Regs = RC.getRegisters();
347 auto &SpillRegs = isAGPRtoVGPR ? SpillAGPR : SpillVGPR;
348 const SIRegisterInfo *TRI = ST.getRegisterInfo();
349 Spill.FullyAllocated = true;
351 // FIXME: Move allocation logic out of MachineFunctionInfo and initialize
352 // once.
353 BitVector OtherUsedRegs;
354 OtherUsedRegs.resize(TRI->getNumRegs());
356 const uint32_t *CSRMask =
357 TRI->getCallPreservedMask(MF, MF.getFunction().getCallingConv());
358 if (CSRMask)
359 OtherUsedRegs.setBitsInMask(CSRMask);
361 // TODO: Should include register tuples, but doesn't matter with current
362 // usage.
363 for (MCPhysReg Reg : SpillAGPR)
364 OtherUsedRegs.set(Reg);
365 for (MCPhysReg Reg : SpillVGPR)
366 OtherUsedRegs.set(Reg);
368 SmallVectorImpl<MCPhysReg>::const_iterator NextSpillReg = Regs.begin();
369 for (unsigned I = 0; I < NumLanes; ++I) {
370 NextSpillReg = std::find_if(
371 NextSpillReg, Regs.end(), [&MRI, &OtherUsedRegs](MCPhysReg Reg) {
372 return MRI.isAllocatable(Reg) && !MRI.isPhysRegUsed(Reg) &&
373 !OtherUsedRegs[Reg];
376 if (NextSpillReg == Regs.end()) { // Registers exhausted
377 Spill.FullyAllocated = false;
378 break;
381 OtherUsedRegs.set(*NextSpillReg);
382 SpillRegs.push_back(*NextSpillReg);
383 Spill.Lanes[I] = *NextSpillReg++;
386 return Spill.FullyAllocated;
389 void SIMachineFunctionInfo::removeDeadFrameIndices(MachineFrameInfo &MFI) {
390 // The FP spill hasn't been inserted yet, so keep it around.
391 for (auto &R : SGPRToVGPRSpills) {
392 if (R.first != FramePointerSaveIndex)
393 MFI.RemoveStackObject(R.first);
396 // All other SPGRs must be allocated on the default stack, so reset the stack
397 // ID.
398 for (int i = MFI.getObjectIndexBegin(), e = MFI.getObjectIndexEnd(); i != e;
399 ++i)
400 if (i != FramePointerSaveIndex)
401 MFI.setStackID(i, TargetStackID::Default);
403 for (auto &R : VGPRToAGPRSpills) {
404 if (R.second.FullyAllocated)
405 MFI.RemoveStackObject(R.first);
409 MCPhysReg SIMachineFunctionInfo::getNextUserSGPR() const {
410 assert(NumSystemSGPRs == 0 && "System SGPRs must be added after user SGPRs");
411 return AMDGPU::SGPR0 + NumUserSGPRs;
414 MCPhysReg SIMachineFunctionInfo::getNextSystemSGPR() const {
415 return AMDGPU::SGPR0 + NumUserSGPRs + NumSystemSGPRs;
418 static yaml::StringValue regToString(unsigned Reg,
419 const TargetRegisterInfo &TRI) {
420 yaml::StringValue Dest;
422 raw_string_ostream OS(Dest.Value);
423 OS << printReg(Reg, &TRI);
425 return Dest;
428 static Optional<yaml::SIArgumentInfo>
429 convertArgumentInfo(const AMDGPUFunctionArgInfo &ArgInfo,
430 const TargetRegisterInfo &TRI) {
431 yaml::SIArgumentInfo AI;
433 auto convertArg = [&](Optional<yaml::SIArgument> &A,
434 const ArgDescriptor &Arg) {
435 if (!Arg)
436 return false;
438 // Create a register or stack argument.
439 yaml::SIArgument SA = yaml::SIArgument::createArgument(Arg.isRegister());
440 if (Arg.isRegister()) {
441 raw_string_ostream OS(SA.RegisterName.Value);
442 OS << printReg(Arg.getRegister(), &TRI);
443 } else
444 SA.StackOffset = Arg.getStackOffset();
445 // Check and update the optional mask.
446 if (Arg.isMasked())
447 SA.Mask = Arg.getMask();
449 A = SA;
450 return true;
453 bool Any = false;
454 Any |= convertArg(AI.PrivateSegmentBuffer, ArgInfo.PrivateSegmentBuffer);
455 Any |= convertArg(AI.DispatchPtr, ArgInfo.DispatchPtr);
456 Any |= convertArg(AI.QueuePtr, ArgInfo.QueuePtr);
457 Any |= convertArg(AI.KernargSegmentPtr, ArgInfo.KernargSegmentPtr);
458 Any |= convertArg(AI.DispatchID, ArgInfo.DispatchID);
459 Any |= convertArg(AI.FlatScratchInit, ArgInfo.FlatScratchInit);
460 Any |= convertArg(AI.PrivateSegmentSize, ArgInfo.PrivateSegmentSize);
461 Any |= convertArg(AI.WorkGroupIDX, ArgInfo.WorkGroupIDX);
462 Any |= convertArg(AI.WorkGroupIDY, ArgInfo.WorkGroupIDY);
463 Any |= convertArg(AI.WorkGroupIDZ, ArgInfo.WorkGroupIDZ);
464 Any |= convertArg(AI.WorkGroupInfo, ArgInfo.WorkGroupInfo);
465 Any |= convertArg(AI.PrivateSegmentWaveByteOffset,
466 ArgInfo.PrivateSegmentWaveByteOffset);
467 Any |= convertArg(AI.ImplicitArgPtr, ArgInfo.ImplicitArgPtr);
468 Any |= convertArg(AI.ImplicitBufferPtr, ArgInfo.ImplicitBufferPtr);
469 Any |= convertArg(AI.WorkItemIDX, ArgInfo.WorkItemIDX);
470 Any |= convertArg(AI.WorkItemIDY, ArgInfo.WorkItemIDY);
471 Any |= convertArg(AI.WorkItemIDZ, ArgInfo.WorkItemIDZ);
473 if (Any)
474 return AI;
476 return None;
479 yaml::SIMachineFunctionInfo::SIMachineFunctionInfo(
480 const llvm::SIMachineFunctionInfo& MFI,
481 const TargetRegisterInfo &TRI)
482 : ExplicitKernArgSize(MFI.getExplicitKernArgSize()),
483 MaxKernArgAlign(MFI.getMaxKernArgAlign()),
484 LDSSize(MFI.getLDSSize()),
485 IsEntryFunction(MFI.isEntryFunction()),
486 NoSignedZerosFPMath(MFI.hasNoSignedZerosFPMath()),
487 MemoryBound(MFI.isMemoryBound()),
488 WaveLimiter(MFI.needsWaveLimiter()),
489 HighBitsOf32BitAddress(MFI.get32BitAddressHighBits()),
490 ScratchRSrcReg(regToString(MFI.getScratchRSrcReg(), TRI)),
491 ScratchWaveOffsetReg(regToString(MFI.getScratchWaveOffsetReg(), TRI)),
492 FrameOffsetReg(regToString(MFI.getFrameOffsetReg(), TRI)),
493 StackPtrOffsetReg(regToString(MFI.getStackPtrOffsetReg(), TRI)),
494 ArgInfo(convertArgumentInfo(MFI.getArgInfo(), TRI)),
495 Mode(MFI.getMode()) {}
497 void yaml::SIMachineFunctionInfo::mappingImpl(yaml::IO &YamlIO) {
498 MappingTraits<SIMachineFunctionInfo>::mapping(YamlIO, *this);
501 bool SIMachineFunctionInfo::initializeBaseYamlFields(
502 const yaml::SIMachineFunctionInfo &YamlMFI) {
503 ExplicitKernArgSize = YamlMFI.ExplicitKernArgSize;
504 MaxKernArgAlign = assumeAligned(YamlMFI.MaxKernArgAlign);
505 LDSSize = YamlMFI.LDSSize;
506 HighBitsOf32BitAddress = YamlMFI.HighBitsOf32BitAddress;
507 IsEntryFunction = YamlMFI.IsEntryFunction;
508 NoSignedZerosFPMath = YamlMFI.NoSignedZerosFPMath;
509 MemoryBound = YamlMFI.MemoryBound;
510 WaveLimiter = YamlMFI.WaveLimiter;
511 return false;