1 //===-- AMDGPUSubtarget.cpp - AMDGPU Subtarget Information ----------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 /// \file 10 /// Implements the AMDGPU specific subclass of TargetSubtarget. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "AMDGPUSubtarget.h" 15 #include "AMDGPUCallLowering.h" 16 #include "AMDGPUInstructionSelector.h" 17 #include "AMDGPULegalizerInfo.h" 18 #include "AMDGPURegisterBankInfo.h" 19 #include "AMDGPUTargetMachine.h" 20 #include "GCNSubtarget.h" 21 #include "R600Subtarget.h" 22 #include "SIMachineFunctionInfo.h" 23 #include "Utils/AMDGPUBaseInfo.h" 24 #include "llvm/ADT/SmallString.h" 25 #include "llvm/CodeGen/GlobalISel/InlineAsmLowering.h" 26 #include "llvm/CodeGen/MachineScheduler.h" 27 #include "llvm/CodeGen/TargetFrameLowering.h" 28 #include "llvm/IR/DiagnosticInfo.h" 29 #include "llvm/IR/IntrinsicsAMDGPU.h" 30 #include "llvm/IR/IntrinsicsR600.h" 31 #include "llvm/IR/MDBuilder.h" 32 #include "llvm/MC/MCSubtargetInfo.h" 33 #include <algorithm> 34 35 using namespace llvm; 36 37 #define DEBUG_TYPE "amdgpu-subtarget" 38 39 #define GET_SUBTARGETINFO_TARGET_DESC 40 #define GET_SUBTARGETINFO_CTOR 41 #define AMDGPUSubtarget GCNSubtarget 42 #include "AMDGPUGenSubtargetInfo.inc" 43 #undef AMDGPUSubtarget 44 45 static cl::opt<bool> EnablePowerSched( 46 "amdgpu-enable-power-sched", 47 cl::desc("Enable scheduling to minimize mAI power bursts"), 48 cl::init(false)); 49 50 static cl::opt<bool> EnableVGPRIndexMode( 51 "amdgpu-vgpr-index-mode", 52 cl::desc("Use GPR indexing mode instead of movrel for vector indexing"), 53 cl::init(false)); 54 55 static cl::opt<bool> UseAA("amdgpu-use-aa-in-codegen", 56 cl::desc("Enable the use of AA during codegen."), 57 cl::init(true)); 58 59 static cl::opt<unsigned> NSAThreshold("amdgpu-nsa-threshold", 60 cl::desc("Number of addresses from which to enable MIMG NSA."), 61 cl::init(3), cl::Hidden); 62 63 GCNSubtarget::~GCNSubtarget() = default; 64 65 GCNSubtarget & 66 GCNSubtarget::initializeSubtargetDependencies(const Triple &TT, 67 StringRef GPU, StringRef FS) { 68 // Determine default and user-specified characteristics 69 // 70 // We want to be able to turn these off, but making this a subtarget feature 71 // for SI has the unhelpful behavior that it unsets everything else if you 72 // disable it. 73 // 74 // Similarly we want enable-prt-strict-null to be on by default and not to 75 // unset everything else if it is disabled 76 77 SmallString<256> FullFS("+promote-alloca,+load-store-opt,+enable-ds128,"); 78 79 // Turn on features that HSA ABI requires. Also turn on FlatForGlobal by default 80 if (isAmdHsaOS()) 81 FullFS += "+flat-for-global,+unaligned-access-mode,+trap-handler,"; 82 83 FullFS += "+enable-prt-strict-null,"; // This is overridden by a disable in FS 84 85 // Disable mutually exclusive bits. 86 if (FS.contains_insensitive("+wavefrontsize")) { 87 if (!FS.contains_insensitive("wavefrontsize16")) 88 FullFS += "-wavefrontsize16,"; 89 if (!FS.contains_insensitive("wavefrontsize32")) 90 FullFS += "-wavefrontsize32,"; 91 if (!FS.contains_insensitive("wavefrontsize64")) 92 FullFS += "-wavefrontsize64,"; 93 } 94 95 FullFS += FS; 96 97 ParseSubtargetFeatures(GPU, /*TuneCPU*/ GPU, FullFS); 98 99 // Implement the "generic" processors, which acts as the default when no 100 // generation features are enabled (e.g for -mcpu=''). HSA OS defaults to 101 // the first amdgcn target that supports flat addressing. Other OSes defaults 102 // to the first amdgcn target. 103 if (Gen == AMDGPUSubtarget::INVALID) { 104 Gen = TT.getOS() == Triple::AMDHSA ? AMDGPUSubtarget::SEA_ISLANDS 105 : AMDGPUSubtarget::SOUTHERN_ISLANDS; 106 } 107 108 if (!hasFeature(AMDGPU::FeatureWavefrontSize32) && 109 !hasFeature(AMDGPU::FeatureWavefrontSize64)) { 110 // If there is no default wave size it must be a generation before gfx10, 111 // these have FeatureWavefrontSize64 in their definition already. For gfx10+ 112 // set wave32 as a default. 113 ToggleFeature(AMDGPU::FeatureWavefrontSize32); 114 } 115 116 // We don't support FP64 for EG/NI atm. 117 assert(!hasFP64() || (getGeneration() >= AMDGPUSubtarget::SOUTHERN_ISLANDS)); 118 119 // Targets must either support 64-bit offsets for MUBUF instructions, and/or 120 // support flat operations, otherwise they cannot access a 64-bit global 121 // address space 122 assert(hasAddr64() || hasFlat()); 123 // Unless +-flat-for-global is specified, turn on FlatForGlobal for targets 124 // that do not support ADDR64 variants of MUBUF instructions. Such targets 125 // cannot use a 64 bit offset with a MUBUF instruction to access the global 126 // address space 127 if (!hasAddr64() && !FS.contains("flat-for-global") && !FlatForGlobal) { 128 ToggleFeature(AMDGPU::FeatureFlatForGlobal); 129 FlatForGlobal = true; 130 } 131 // Unless +-flat-for-global is specified, use MUBUF instructions for global 132 // address space access if flat operations are not available. 133 if (!hasFlat() && !FS.contains("flat-for-global") && FlatForGlobal) { 134 ToggleFeature(AMDGPU::FeatureFlatForGlobal); 135 FlatForGlobal = false; 136 } 137 138 // Set defaults if needed. 139 if (MaxPrivateElementSize == 0) 140 MaxPrivateElementSize = 4; 141 142 if (LDSBankCount == 0) 143 LDSBankCount = 32; 144 145 if (TT.getArch() == Triple::amdgcn) { 146 if (LocalMemorySize == 0) 147 LocalMemorySize = 32768; 148 149 // Do something sensible for unspecified target. 150 if (!HasMovrel && !HasVGPRIndexMode) 151 HasMovrel = true; 152 } 153 154 AddressableLocalMemorySize = LocalMemorySize; 155 156 if (AMDGPU::isGFX10Plus(*this) && 157 !getFeatureBits().test(AMDGPU::FeatureCuMode)) 158 LocalMemorySize *= 2; 159 160 // Don't crash on invalid devices. 161 if (WavefrontSizeLog2 == 0) 162 WavefrontSizeLog2 = 5; 163 164 HasFminFmaxLegacy = getGeneration() < AMDGPUSubtarget::VOLCANIC_ISLANDS; 165 HasSMulHi = getGeneration() >= AMDGPUSubtarget::GFX9; 166 167 TargetID.setTargetIDFromFeaturesString(FS); 168 169 LLVM_DEBUG(dbgs() << "xnack setting for subtarget: " 170 << TargetID.getXnackSetting() << '\n'); 171 LLVM_DEBUG(dbgs() << "sramecc setting for subtarget: " 172 << TargetID.getSramEccSetting() << '\n'); 173 174 return *this; 175 } 176 177 void GCNSubtarget::checkSubtargetFeatures(const Function &F) const { 178 LLVMContext &Ctx = F.getContext(); 179 if (hasFeature(AMDGPU::FeatureWavefrontSize32) == 180 hasFeature(AMDGPU::FeatureWavefrontSize64)) { 181 Ctx.diagnose(DiagnosticInfoUnsupported( 182 F, "must specify exactly one of wavefrontsize32 and wavefrontsize64")); 183 } 184 } 185 186 AMDGPUSubtarget::AMDGPUSubtarget(Triple TT) : TargetTriple(std::move(TT)) {} 187 188 bool AMDGPUSubtarget::useRealTrue16Insts() const { 189 return hasTrue16BitInsts() && EnableRealTrue16Insts; 190 } 191 192 GCNSubtarget::GCNSubtarget(const Triple &TT, StringRef GPU, StringRef FS, 193 const GCNTargetMachine &TM) 194 : // clang-format off 195 AMDGPUGenSubtargetInfo(TT, GPU, /*TuneCPU*/ GPU, FS), 196 AMDGPUSubtarget(TT), 197 TargetTriple(TT), 198 TargetID(*this), 199 InstrItins(getInstrItineraryForCPU(GPU)), 200 InstrInfo(initializeSubtargetDependencies(TT, GPU, FS)), 201 TLInfo(TM, *this), 202 FrameLowering(TargetFrameLowering::StackGrowsUp, getStackAlignment(), 0) { 203 // clang-format on 204 MaxWavesPerEU = AMDGPU::IsaInfo::getMaxWavesPerEU(this); 205 EUsPerCU = AMDGPU::IsaInfo::getEUsPerCU(this); 206 CallLoweringInfo = std::make_unique<AMDGPUCallLowering>(*getTargetLowering()); 207 InlineAsmLoweringInfo = 208 std::make_unique<InlineAsmLowering>(getTargetLowering()); 209 Legalizer = std::make_unique<AMDGPULegalizerInfo>(*this, TM); 210 RegBankInfo = std::make_unique<AMDGPURegisterBankInfo>(*this); 211 InstSelector = 212 std::make_unique<AMDGPUInstructionSelector>(*this, *RegBankInfo, TM); 213 } 214 215 unsigned GCNSubtarget::getConstantBusLimit(unsigned Opcode) const { 216 if (getGeneration() < GFX10) 217 return 1; 218 219 switch (Opcode) { 220 case AMDGPU::V_LSHLREV_B64_e64: 221 case AMDGPU::V_LSHLREV_B64_gfx10: 222 case AMDGPU::V_LSHLREV_B64_e64_gfx11: 223 case AMDGPU::V_LSHLREV_B64_e32_gfx12: 224 case AMDGPU::V_LSHLREV_B64_e64_gfx12: 225 case AMDGPU::V_LSHL_B64_e64: 226 case AMDGPU::V_LSHRREV_B64_e64: 227 case AMDGPU::V_LSHRREV_B64_gfx10: 228 case AMDGPU::V_LSHRREV_B64_e64_gfx11: 229 case AMDGPU::V_LSHRREV_B64_e64_gfx12: 230 case AMDGPU::V_LSHR_B64_e64: 231 case AMDGPU::V_ASHRREV_I64_e64: 232 case AMDGPU::V_ASHRREV_I64_gfx10: 233 case AMDGPU::V_ASHRREV_I64_e64_gfx11: 234 case AMDGPU::V_ASHRREV_I64_e64_gfx12: 235 case AMDGPU::V_ASHR_I64_e64: 236 return 1; 237 } 238 239 return 2; 240 } 241 242 /// This list was mostly derived from experimentation. 243 bool GCNSubtarget::zeroesHigh16BitsOfDest(unsigned Opcode) const { 244 switch (Opcode) { 245 case AMDGPU::V_CVT_F16_F32_e32: 246 case AMDGPU::V_CVT_F16_F32_e64: 247 case AMDGPU::V_CVT_F16_U16_e32: 248 case AMDGPU::V_CVT_F16_U16_e64: 249 case AMDGPU::V_CVT_F16_I16_e32: 250 case AMDGPU::V_CVT_F16_I16_e64: 251 case AMDGPU::V_RCP_F16_e64: 252 case AMDGPU::V_RCP_F16_e32: 253 case AMDGPU::V_RSQ_F16_e64: 254 case AMDGPU::V_RSQ_F16_e32: 255 case AMDGPU::V_SQRT_F16_e64: 256 case AMDGPU::V_SQRT_F16_e32: 257 case AMDGPU::V_LOG_F16_e64: 258 case AMDGPU::V_LOG_F16_e32: 259 case AMDGPU::V_EXP_F16_e64: 260 case AMDGPU::V_EXP_F16_e32: 261 case AMDGPU::V_SIN_F16_e64: 262 case AMDGPU::V_SIN_F16_e32: 263 case AMDGPU::V_COS_F16_e64: 264 case AMDGPU::V_COS_F16_e32: 265 case AMDGPU::V_FLOOR_F16_e64: 266 case AMDGPU::V_FLOOR_F16_e32: 267 case AMDGPU::V_CEIL_F16_e64: 268 case AMDGPU::V_CEIL_F16_e32: 269 case AMDGPU::V_TRUNC_F16_e64: 270 case AMDGPU::V_TRUNC_F16_e32: 271 case AMDGPU::V_RNDNE_F16_e64: 272 case AMDGPU::V_RNDNE_F16_e32: 273 case AMDGPU::V_FRACT_F16_e64: 274 case AMDGPU::V_FRACT_F16_e32: 275 case AMDGPU::V_FREXP_MANT_F16_e64: 276 case AMDGPU::V_FREXP_MANT_F16_e32: 277 case AMDGPU::V_FREXP_EXP_I16_F16_e64: 278 case AMDGPU::V_FREXP_EXP_I16_F16_e32: 279 case AMDGPU::V_LDEXP_F16_e64: 280 case AMDGPU::V_LDEXP_F16_e32: 281 case AMDGPU::V_LSHLREV_B16_e64: 282 case AMDGPU::V_LSHLREV_B16_e32: 283 case AMDGPU::V_LSHRREV_B16_e64: 284 case AMDGPU::V_LSHRREV_B16_e32: 285 case AMDGPU::V_ASHRREV_I16_e64: 286 case AMDGPU::V_ASHRREV_I16_e32: 287 case AMDGPU::V_ADD_U16_e64: 288 case AMDGPU::V_ADD_U16_e32: 289 case AMDGPU::V_SUB_U16_e64: 290 case AMDGPU::V_SUB_U16_e32: 291 case AMDGPU::V_SUBREV_U16_e64: 292 case AMDGPU::V_SUBREV_U16_e32: 293 case AMDGPU::V_MUL_LO_U16_e64: 294 case AMDGPU::V_MUL_LO_U16_e32: 295 case AMDGPU::V_ADD_F16_e64: 296 case AMDGPU::V_ADD_F16_e32: 297 case AMDGPU::V_SUB_F16_e64: 298 case AMDGPU::V_SUB_F16_e32: 299 case AMDGPU::V_SUBREV_F16_e64: 300 case AMDGPU::V_SUBREV_F16_e32: 301 case AMDGPU::V_MUL_F16_e64: 302 case AMDGPU::V_MUL_F16_e32: 303 case AMDGPU::V_MAX_F16_e64: 304 case AMDGPU::V_MAX_F16_e32: 305 case AMDGPU::V_MIN_F16_e64: 306 case AMDGPU::V_MIN_F16_e32: 307 case AMDGPU::V_MAX_U16_e64: 308 case AMDGPU::V_MAX_U16_e32: 309 case AMDGPU::V_MIN_U16_e64: 310 case AMDGPU::V_MIN_U16_e32: 311 case AMDGPU::V_MAX_I16_e64: 312 case AMDGPU::V_MAX_I16_e32: 313 case AMDGPU::V_MIN_I16_e64: 314 case AMDGPU::V_MIN_I16_e32: 315 case AMDGPU::V_MAD_F16_e64: 316 case AMDGPU::V_MAD_U16_e64: 317 case AMDGPU::V_MAD_I16_e64: 318 case AMDGPU::V_FMA_F16_e64: 319 case AMDGPU::V_DIV_FIXUP_F16_e64: 320 // On gfx10, all 16-bit instructions preserve the high bits. 321 return getGeneration() <= AMDGPUSubtarget::GFX9; 322 case AMDGPU::V_MADAK_F16: 323 case AMDGPU::V_MADMK_F16: 324 case AMDGPU::V_MAC_F16_e64: 325 case AMDGPU::V_MAC_F16_e32: 326 case AMDGPU::V_FMAMK_F16: 327 case AMDGPU::V_FMAAK_F16: 328 case AMDGPU::V_FMAC_F16_e64: 329 case AMDGPU::V_FMAC_F16_e32: 330 // In gfx9, the preferred handling of the unused high 16-bits changed. Most 331 // instructions maintain the legacy behavior of 0ing. Some instructions 332 // changed to preserving the high bits. 333 return getGeneration() == AMDGPUSubtarget::VOLCANIC_ISLANDS; 334 case AMDGPU::V_MAD_MIXLO_F16: 335 case AMDGPU::V_MAD_MIXHI_F16: 336 default: 337 return false; 338 } 339 } 340 341 // Returns the maximum per-workgroup LDS allocation size (in bytes) that still 342 // allows the given function to achieve an occupancy of NWaves waves per 343 // SIMD / EU, taking into account only the function's *maximum* workgroup size. 344 unsigned 345 AMDGPUSubtarget::getMaxLocalMemSizeWithWaveCount(unsigned NWaves, 346 const Function &F) const { 347 const unsigned WaveSize = getWavefrontSize(); 348 const unsigned WorkGroupSize = getFlatWorkGroupSizes(F).second; 349 const unsigned WavesPerWorkgroup = 350 std::max(1u, (WorkGroupSize + WaveSize - 1) / WaveSize); 351 352 const unsigned WorkGroupsPerCU = 353 std::max(1u, (NWaves * getEUsPerCU()) / WavesPerWorkgroup); 354 355 return getLocalMemorySize() / WorkGroupsPerCU; 356 } 357 358 // FIXME: Should return min,max range. 359 // 360 // Returns the maximum occupancy, in number of waves per SIMD / EU, that can 361 // be achieved when only the given function is running on the machine; and 362 // taking into account the overall number of wave slots, the (maximum) workgroup 363 // size, and the per-workgroup LDS allocation size. 364 unsigned AMDGPUSubtarget::getOccupancyWithLocalMemSize(uint32_t Bytes, 365 const Function &F) const { 366 const unsigned MaxWorkGroupSize = getFlatWorkGroupSizes(F).second; 367 const unsigned MaxWorkGroupsPerCu = getMaxWorkGroupsPerCU(MaxWorkGroupSize); 368 if (!MaxWorkGroupsPerCu) 369 return 0; 370 371 const unsigned WaveSize = getWavefrontSize(); 372 373 // FIXME: Do we need to account for alignment requirement of LDS rounding the 374 // size up? 375 // Compute restriction based on LDS usage 376 unsigned NumGroups = getLocalMemorySize() / (Bytes ? Bytes : 1u); 377 378 // This can be queried with more LDS than is possible, so just assume the 379 // worst. 380 if (NumGroups == 0) 381 return 1; 382 383 NumGroups = std::min(MaxWorkGroupsPerCu, NumGroups); 384 385 // Round to the number of waves per CU. 386 const unsigned MaxGroupNumWaves = divideCeil(MaxWorkGroupSize, WaveSize); 387 unsigned MaxWaves = NumGroups * MaxGroupNumWaves; 388 389 // Number of waves per EU (SIMD). 390 MaxWaves = divideCeil(MaxWaves, getEUsPerCU()); 391 392 // Clamp to the maximum possible number of waves. 393 MaxWaves = std::min(MaxWaves, getMaxWavesPerEU()); 394 395 // FIXME: Needs to be a multiple of the group size? 396 //MaxWaves = MaxGroupNumWaves * (MaxWaves / MaxGroupNumWaves); 397 398 assert(MaxWaves > 0 && MaxWaves <= getMaxWavesPerEU() && 399 "computed invalid occupancy"); 400 return MaxWaves; 401 } 402 403 unsigned 404 AMDGPUSubtarget::getOccupancyWithLocalMemSize(const MachineFunction &MF) const { 405 const auto *MFI = MF.getInfo<SIMachineFunctionInfo>(); 406 return getOccupancyWithLocalMemSize(MFI->getLDSSize(), MF.getFunction()); 407 } 408 409 std::pair<unsigned, unsigned> 410 AMDGPUSubtarget::getDefaultFlatWorkGroupSize(CallingConv::ID CC) const { 411 switch (CC) { 412 case CallingConv::AMDGPU_VS: 413 case CallingConv::AMDGPU_LS: 414 case CallingConv::AMDGPU_HS: 415 case CallingConv::AMDGPU_ES: 416 case CallingConv::AMDGPU_GS: 417 case CallingConv::AMDGPU_PS: 418 return std::pair(1, getWavefrontSize()); 419 default: 420 return std::pair(1u, getMaxFlatWorkGroupSize()); 421 } 422 } 423 424 std::pair<unsigned, unsigned> AMDGPUSubtarget::getFlatWorkGroupSizes( 425 const Function &F) const { 426 // Default minimum/maximum flat work group sizes. 427 std::pair<unsigned, unsigned> Default = 428 getDefaultFlatWorkGroupSize(F.getCallingConv()); 429 430 // Requested minimum/maximum flat work group sizes. 431 std::pair<unsigned, unsigned> Requested = AMDGPU::getIntegerPairAttribute( 432 F, "amdgpu-flat-work-group-size", Default); 433 434 // Make sure requested minimum is less than requested maximum. 435 if (Requested.first > Requested.second) 436 return Default; 437 438 // Make sure requested values do not violate subtarget's specifications. 439 if (Requested.first < getMinFlatWorkGroupSize()) 440 return Default; 441 if (Requested.second > getMaxFlatWorkGroupSize()) 442 return Default; 443 444 return Requested; 445 } 446 447 std::pair<unsigned, unsigned> AMDGPUSubtarget::getEffectiveWavesPerEU( 448 std::pair<unsigned, unsigned> Requested, 449 std::pair<unsigned, unsigned> FlatWorkGroupSizes) const { 450 // Default minimum/maximum number of waves per execution unit. 451 std::pair<unsigned, unsigned> Default(1, getMaxWavesPerEU()); 452 453 // If minimum/maximum flat work group sizes were explicitly requested using 454 // "amdgpu-flat-workgroup-size" attribute, then set default minimum/maximum 455 // number of waves per execution unit to values implied by requested 456 // minimum/maximum flat work group sizes. 457 unsigned MinImpliedByFlatWorkGroupSize = 458 getWavesPerEUForWorkGroup(FlatWorkGroupSizes.second); 459 Default.first = MinImpliedByFlatWorkGroupSize; 460 461 // Make sure requested minimum is less than requested maximum. 462 if (Requested.second && Requested.first > Requested.second) 463 return Default; 464 465 // Make sure requested values do not violate subtarget's specifications. 466 if (Requested.first < getMinWavesPerEU() || 467 Requested.second > getMaxWavesPerEU()) 468 return Default; 469 470 // Make sure requested values are compatible with values implied by requested 471 // minimum/maximum flat work group sizes. 472 if (Requested.first < MinImpliedByFlatWorkGroupSize) 473 return Default; 474 475 return Requested; 476 } 477 478 std::pair<unsigned, unsigned> AMDGPUSubtarget::getWavesPerEU( 479 const Function &F, std::pair<unsigned, unsigned> FlatWorkGroupSizes) const { 480 // Default minimum/maximum number of waves per execution unit. 481 std::pair<unsigned, unsigned> Default(1, getMaxWavesPerEU()); 482 483 // Requested minimum/maximum number of waves per execution unit. 484 std::pair<unsigned, unsigned> Requested = 485 AMDGPU::getIntegerPairAttribute(F, "amdgpu-waves-per-eu", Default, true); 486 return getEffectiveWavesPerEU(Requested, FlatWorkGroupSizes); 487 } 488 489 static unsigned getReqdWorkGroupSize(const Function &Kernel, unsigned Dim) { 490 auto Node = Kernel.getMetadata("reqd_work_group_size"); 491 if (Node && Node->getNumOperands() == 3) 492 return mdconst::extract<ConstantInt>(Node->getOperand(Dim))->getZExtValue(); 493 return std::numeric_limits<unsigned>::max(); 494 } 495 496 bool AMDGPUSubtarget::isMesaKernel(const Function &F) const { 497 return isMesa3DOS() && !AMDGPU::isShader(F.getCallingConv()); 498 } 499 500 unsigned AMDGPUSubtarget::getMaxWorkitemID(const Function &Kernel, 501 unsigned Dimension) const { 502 unsigned ReqdSize = getReqdWorkGroupSize(Kernel, Dimension); 503 if (ReqdSize != std::numeric_limits<unsigned>::max()) 504 return ReqdSize - 1; 505 return getFlatWorkGroupSizes(Kernel).second - 1; 506 } 507 508 bool AMDGPUSubtarget::isSingleLaneExecution(const Function &Func) const { 509 for (int I = 0; I < 3; ++I) { 510 if (getMaxWorkitemID(Func, I) > 0) 511 return false; 512 } 513 514 return true; 515 } 516 517 bool AMDGPUSubtarget::makeLIDRangeMetadata(Instruction *I) const { 518 Function *Kernel = I->getParent()->getParent(); 519 unsigned MinSize = 0; 520 unsigned MaxSize = getFlatWorkGroupSizes(*Kernel).second; 521 bool IdQuery = false; 522 523 // If reqd_work_group_size is present it narrows value down. 524 if (auto *CI = dyn_cast<CallInst>(I)) { 525 const Function *F = CI->getCalledFunction(); 526 if (F) { 527 unsigned Dim = UINT_MAX; 528 switch (F->getIntrinsicID()) { 529 case Intrinsic::amdgcn_workitem_id_x: 530 case Intrinsic::r600_read_tidig_x: 531 IdQuery = true; 532 [[fallthrough]]; 533 case Intrinsic::r600_read_local_size_x: 534 Dim = 0; 535 break; 536 case Intrinsic::amdgcn_workitem_id_y: 537 case Intrinsic::r600_read_tidig_y: 538 IdQuery = true; 539 [[fallthrough]]; 540 case Intrinsic::r600_read_local_size_y: 541 Dim = 1; 542 break; 543 case Intrinsic::amdgcn_workitem_id_z: 544 case Intrinsic::r600_read_tidig_z: 545 IdQuery = true; 546 [[fallthrough]]; 547 case Intrinsic::r600_read_local_size_z: 548 Dim = 2; 549 break; 550 default: 551 break; 552 } 553 554 if (Dim <= 3) { 555 unsigned ReqdSize = getReqdWorkGroupSize(*Kernel, Dim); 556 if (ReqdSize != std::numeric_limits<unsigned>::max()) 557 MinSize = MaxSize = ReqdSize; 558 } 559 } 560 } 561 562 if (!MaxSize) 563 return false; 564 565 // Range metadata is [Lo, Hi). For ID query we need to pass max size 566 // as Hi. For size query we need to pass Hi + 1. 567 if (IdQuery) 568 MinSize = 0; 569 else 570 ++MaxSize; 571 572 APInt Lower{32, MinSize}; 573 APInt Upper{32, MaxSize}; 574 if (auto *CI = dyn_cast<CallBase>(I)) { 575 ConstantRange Range(Lower, Upper); 576 CI->addRangeRetAttr(Range); 577 } else { 578 MDBuilder MDB(I->getContext()); 579 MDNode *MaxWorkGroupSizeRange = MDB.createRange(Lower, Upper); 580 I->setMetadata(LLVMContext::MD_range, MaxWorkGroupSizeRange); 581 } 582 return true; 583 } 584 585 unsigned AMDGPUSubtarget::getImplicitArgNumBytes(const Function &F) const { 586 assert(AMDGPU::isKernel(F.getCallingConv())); 587 588 // We don't allocate the segment if we know the implicit arguments weren't 589 // used, even if the ABI implies we need them. 590 if (F.hasFnAttribute("amdgpu-no-implicitarg-ptr")) 591 return 0; 592 593 if (isMesaKernel(F)) 594 return 16; 595 596 // Assume all implicit inputs are used by default 597 const Module *M = F.getParent(); 598 unsigned NBytes = 599 AMDGPU::getAMDHSACodeObjectVersion(*M) >= AMDGPU::AMDHSA_COV5 ? 256 : 56; 600 return F.getFnAttributeAsParsedInteger("amdgpu-implicitarg-num-bytes", 601 NBytes); 602 } 603 604 uint64_t AMDGPUSubtarget::getExplicitKernArgSize(const Function &F, 605 Align &MaxAlign) const { 606 assert(F.getCallingConv() == CallingConv::AMDGPU_KERNEL || 607 F.getCallingConv() == CallingConv::SPIR_KERNEL); 608 609 const DataLayout &DL = F.getDataLayout(); 610 uint64_t ExplicitArgBytes = 0; 611 MaxAlign = Align(1); 612 613 for (const Argument &Arg : F.args()) { 614 const bool IsByRef = Arg.hasByRefAttr(); 615 Type *ArgTy = IsByRef ? Arg.getParamByRefType() : Arg.getType(); 616 Align Alignment = DL.getValueOrABITypeAlignment( 617 IsByRef ? Arg.getParamAlign() : std::nullopt, ArgTy); 618 uint64_t AllocSize = DL.getTypeAllocSize(ArgTy); 619 ExplicitArgBytes = alignTo(ExplicitArgBytes, Alignment) + AllocSize; 620 MaxAlign = std::max(MaxAlign, Alignment); 621 } 622 623 return ExplicitArgBytes; 624 } 625 626 unsigned AMDGPUSubtarget::getKernArgSegmentSize(const Function &F, 627 Align &MaxAlign) const { 628 if (F.getCallingConv() != CallingConv::AMDGPU_KERNEL && 629 F.getCallingConv() != CallingConv::SPIR_KERNEL) 630 return 0; 631 632 uint64_t ExplicitArgBytes = getExplicitKernArgSize(F, MaxAlign); 633 634 unsigned ExplicitOffset = getExplicitKernelArgOffset(); 635 636 uint64_t TotalSize = ExplicitOffset + ExplicitArgBytes; 637 unsigned ImplicitBytes = getImplicitArgNumBytes(F); 638 if (ImplicitBytes != 0) { 639 const Align Alignment = getAlignmentForImplicitArgPtr(); 640 TotalSize = alignTo(ExplicitArgBytes, Alignment) + ImplicitBytes; 641 MaxAlign = std::max(MaxAlign, Alignment); 642 } 643 644 // Being able to dereference past the end is useful for emitting scalar loads. 645 return alignTo(TotalSize, 4); 646 } 647 648 AMDGPUDwarfFlavour AMDGPUSubtarget::getAMDGPUDwarfFlavour() const { 649 return getWavefrontSize() == 32 ? AMDGPUDwarfFlavour::Wave32 650 : AMDGPUDwarfFlavour::Wave64; 651 } 652 653 void GCNSubtarget::overrideSchedPolicy(MachineSchedPolicy &Policy, 654 unsigned NumRegionInstrs) const { 655 // Track register pressure so the scheduler can try to decrease 656 // pressure once register usage is above the threshold defined by 657 // SIRegisterInfo::getRegPressureSetLimit() 658 Policy.ShouldTrackPressure = true; 659 660 // Enabling both top down and bottom up scheduling seems to give us less 661 // register spills than just using one of these approaches on its own. 662 Policy.OnlyTopDown = false; 663 Policy.OnlyBottomUp = false; 664 665 // Enabling ShouldTrackLaneMasks crashes the SI Machine Scheduler. 666 if (!enableSIScheduler()) 667 Policy.ShouldTrackLaneMasks = true; 668 } 669 670 void GCNSubtarget::mirFileLoaded(MachineFunction &MF) const { 671 if (isWave32()) { 672 // Fix implicit $vcc operands after MIParser has verified that they match 673 // the instruction definitions. 674 for (auto &MBB : MF) { 675 for (auto &MI : MBB) 676 InstrInfo.fixImplicitOperands(MI); 677 } 678 } 679 } 680 681 bool GCNSubtarget::hasMadF16() const { 682 return InstrInfo.pseudoToMCOpcode(AMDGPU::V_MAD_F16_e64) != -1; 683 } 684 685 bool GCNSubtarget::useVGPRIndexMode() const { 686 return !hasMovrel() || (EnableVGPRIndexMode && hasVGPRIndexMode()); 687 } 688 689 bool GCNSubtarget::useAA() const { return UseAA; } 690 691 unsigned GCNSubtarget::getOccupancyWithNumSGPRs(unsigned SGPRs) const { 692 return AMDGPU::IsaInfo::getOccupancyWithNumSGPRs(SGPRs, getMaxWavesPerEU(), 693 getGeneration()); 694 } 695 696 unsigned GCNSubtarget::getOccupancyWithNumVGPRs(unsigned NumVGPRs) const { 697 return AMDGPU::IsaInfo::getNumWavesPerEUWithNumVGPRs(this, NumVGPRs); 698 } 699 700 unsigned 701 GCNSubtarget::getBaseReservedNumSGPRs(const bool HasFlatScratch) const { 702 if (getGeneration() >= AMDGPUSubtarget::GFX10) 703 return 2; // VCC. FLAT_SCRATCH and XNACK are no longer in SGPRs. 704 705 if (HasFlatScratch || HasArchitectedFlatScratch) { 706 if (getGeneration() >= AMDGPUSubtarget::VOLCANIC_ISLANDS) 707 return 6; // FLAT_SCRATCH, XNACK, VCC (in that order). 708 if (getGeneration() == AMDGPUSubtarget::SEA_ISLANDS) 709 return 4; // FLAT_SCRATCH, VCC (in that order). 710 } 711 712 if (isXNACKEnabled()) 713 return 4; // XNACK, VCC (in that order). 714 return 2; // VCC. 715 } 716 717 unsigned GCNSubtarget::getReservedNumSGPRs(const MachineFunction &MF) const { 718 const SIMachineFunctionInfo &MFI = *MF.getInfo<SIMachineFunctionInfo>(); 719 return getBaseReservedNumSGPRs(MFI.getUserSGPRInfo().hasFlatScratchInit()); 720 } 721 722 unsigned GCNSubtarget::getReservedNumSGPRs(const Function &F) const { 723 // In principle we do not need to reserve SGPR pair used for flat_scratch if 724 // we know flat instructions do not access the stack anywhere in the 725 // program. For now assume it's needed if we have flat instructions. 726 const bool KernelUsesFlatScratch = hasFlatAddressSpace(); 727 return getBaseReservedNumSGPRs(KernelUsesFlatScratch); 728 } 729 730 unsigned GCNSubtarget::computeOccupancy(const Function &F, unsigned LDSSize, 731 unsigned NumSGPRs, 732 unsigned NumVGPRs) const { 733 unsigned Occupancy = 734 std::min(getMaxWavesPerEU(), 735 getOccupancyWithLocalMemSize(LDSSize, F)); 736 if (NumSGPRs) 737 Occupancy = std::min(Occupancy, getOccupancyWithNumSGPRs(NumSGPRs)); 738 if (NumVGPRs) 739 Occupancy = std::min(Occupancy, getOccupancyWithNumVGPRs(NumVGPRs)); 740 return Occupancy; 741 } 742 743 unsigned GCNSubtarget::getBaseMaxNumSGPRs( 744 const Function &F, std::pair<unsigned, unsigned> WavesPerEU, 745 unsigned PreloadedSGPRs, unsigned ReservedNumSGPRs) const { 746 // Compute maximum number of SGPRs function can use using default/requested 747 // minimum number of waves per execution unit. 748 unsigned MaxNumSGPRs = getMaxNumSGPRs(WavesPerEU.first, false); 749 unsigned MaxAddressableNumSGPRs = getMaxNumSGPRs(WavesPerEU.first, true); 750 751 // Check if maximum number of SGPRs was explicitly requested using 752 // "amdgpu-num-sgpr" attribute. 753 if (F.hasFnAttribute("amdgpu-num-sgpr")) { 754 unsigned Requested = 755 F.getFnAttributeAsParsedInteger("amdgpu-num-sgpr", MaxNumSGPRs); 756 757 // Make sure requested value does not violate subtarget's specifications. 758 if (Requested && (Requested <= ReservedNumSGPRs)) 759 Requested = 0; 760 761 // If more SGPRs are required to support the input user/system SGPRs, 762 // increase to accommodate them. 763 // 764 // FIXME: This really ends up using the requested number of SGPRs + number 765 // of reserved special registers in total. Theoretically you could re-use 766 // the last input registers for these special registers, but this would 767 // require a lot of complexity to deal with the weird aliasing. 768 unsigned InputNumSGPRs = PreloadedSGPRs; 769 if (Requested && Requested < InputNumSGPRs) 770 Requested = InputNumSGPRs; 771 772 // Make sure requested value is compatible with values implied by 773 // default/requested minimum/maximum number of waves per execution unit. 774 if (Requested && Requested > getMaxNumSGPRs(WavesPerEU.first, false)) 775 Requested = 0; 776 if (WavesPerEU.second && 777 Requested && Requested < getMinNumSGPRs(WavesPerEU.second)) 778 Requested = 0; 779 780 if (Requested) 781 MaxNumSGPRs = Requested; 782 } 783 784 if (hasSGPRInitBug()) 785 MaxNumSGPRs = AMDGPU::IsaInfo::FIXED_NUM_SGPRS_FOR_INIT_BUG; 786 787 return std::min(MaxNumSGPRs - ReservedNumSGPRs, MaxAddressableNumSGPRs); 788 } 789 790 unsigned GCNSubtarget::getMaxNumSGPRs(const MachineFunction &MF) const { 791 const Function &F = MF.getFunction(); 792 const SIMachineFunctionInfo &MFI = *MF.getInfo<SIMachineFunctionInfo>(); 793 return getBaseMaxNumSGPRs(F, MFI.getWavesPerEU(), MFI.getNumPreloadedSGPRs(), 794 getReservedNumSGPRs(MF)); 795 } 796 797 static unsigned getMaxNumPreloadedSGPRs() { 798 using USI = GCNUserSGPRUsageInfo; 799 // Max number of user SGPRs 800 const unsigned MaxUserSGPRs = 801 USI::getNumUserSGPRForField(USI::PrivateSegmentBufferID) + 802 USI::getNumUserSGPRForField(USI::DispatchPtrID) + 803 USI::getNumUserSGPRForField(USI::QueuePtrID) + 804 USI::getNumUserSGPRForField(USI::KernargSegmentPtrID) + 805 USI::getNumUserSGPRForField(USI::DispatchIdID) + 806 USI::getNumUserSGPRForField(USI::FlatScratchInitID) + 807 USI::getNumUserSGPRForField(USI::ImplicitBufferPtrID); 808 809 // Max number of system SGPRs 810 const unsigned MaxSystemSGPRs = 1 + // WorkGroupIDX 811 1 + // WorkGroupIDY 812 1 + // WorkGroupIDZ 813 1 + // WorkGroupInfo 814 1; // private segment wave byte offset 815 816 // Max number of synthetic SGPRs 817 const unsigned SyntheticSGPRs = 1; // LDSKernelId 818 819 return MaxUserSGPRs + MaxSystemSGPRs + SyntheticSGPRs; 820 } 821 822 unsigned GCNSubtarget::getMaxNumSGPRs(const Function &F) const { 823 return getBaseMaxNumSGPRs(F, getWavesPerEU(F), getMaxNumPreloadedSGPRs(), 824 getReservedNumSGPRs(F)); 825 } 826 827 unsigned GCNSubtarget::getBaseMaxNumVGPRs( 828 const Function &F, std::pair<unsigned, unsigned> WavesPerEU) const { 829 // Compute maximum number of VGPRs function can use using default/requested 830 // minimum number of waves per execution unit. 831 unsigned MaxNumVGPRs = getMaxNumVGPRs(WavesPerEU.first); 832 833 // Check if maximum number of VGPRs was explicitly requested using 834 // "amdgpu-num-vgpr" attribute. 835 if (F.hasFnAttribute("amdgpu-num-vgpr")) { 836 unsigned Requested = 837 F.getFnAttributeAsParsedInteger("amdgpu-num-vgpr", MaxNumVGPRs); 838 839 if (hasGFX90AInsts()) 840 Requested *= 2; 841 842 // Make sure requested value is compatible with values implied by 843 // default/requested minimum/maximum number of waves per execution unit. 844 if (Requested && Requested > getMaxNumVGPRs(WavesPerEU.first)) 845 Requested = 0; 846 if (WavesPerEU.second && 847 Requested && Requested < getMinNumVGPRs(WavesPerEU.second)) 848 Requested = 0; 849 850 if (Requested) 851 MaxNumVGPRs = Requested; 852 } 853 854 return MaxNumVGPRs; 855 } 856 857 unsigned GCNSubtarget::getMaxNumVGPRs(const Function &F) const { 858 return getBaseMaxNumVGPRs(F, getWavesPerEU(F)); 859 } 860 861 unsigned GCNSubtarget::getMaxNumVGPRs(const MachineFunction &MF) const { 862 const Function &F = MF.getFunction(); 863 const SIMachineFunctionInfo &MFI = *MF.getInfo<SIMachineFunctionInfo>(); 864 return getBaseMaxNumVGPRs(F, MFI.getWavesPerEU()); 865 } 866 867 void GCNSubtarget::adjustSchedDependency( 868 SUnit *Def, int DefOpIdx, SUnit *Use, int UseOpIdx, SDep &Dep, 869 const TargetSchedModel *SchedModel) const { 870 if (Dep.getKind() != SDep::Kind::Data || !Dep.getReg() || 871 !Def->isInstr() || !Use->isInstr()) 872 return; 873 874 MachineInstr *DefI = Def->getInstr(); 875 MachineInstr *UseI = Use->getInstr(); 876 877 if (DefI->isBundle()) { 878 const SIRegisterInfo *TRI = getRegisterInfo(); 879 auto Reg = Dep.getReg(); 880 MachineBasicBlock::const_instr_iterator I(DefI->getIterator()); 881 MachineBasicBlock::const_instr_iterator E(DefI->getParent()->instr_end()); 882 unsigned Lat = 0; 883 for (++I; I != E && I->isBundledWithPred(); ++I) { 884 if (I->modifiesRegister(Reg, TRI)) 885 Lat = InstrInfo.getInstrLatency(getInstrItineraryData(), *I); 886 else if (Lat) 887 --Lat; 888 } 889 Dep.setLatency(Lat); 890 } else if (UseI->isBundle()) { 891 const SIRegisterInfo *TRI = getRegisterInfo(); 892 auto Reg = Dep.getReg(); 893 MachineBasicBlock::const_instr_iterator I(UseI->getIterator()); 894 MachineBasicBlock::const_instr_iterator E(UseI->getParent()->instr_end()); 895 unsigned Lat = InstrInfo.getInstrLatency(getInstrItineraryData(), *DefI); 896 for (++I; I != E && I->isBundledWithPred() && Lat; ++I) { 897 if (I->readsRegister(Reg, TRI)) 898 break; 899 --Lat; 900 } 901 Dep.setLatency(Lat); 902 } else if (Dep.getLatency() == 0 && Dep.getReg() == AMDGPU::VCC_LO) { 903 // Work around the fact that SIInstrInfo::fixImplicitOperands modifies 904 // implicit operands which come from the MCInstrDesc, which can fool 905 // ScheduleDAGInstrs::addPhysRegDataDeps into treating them as implicit 906 // pseudo operands. 907 Dep.setLatency(InstrInfo.getSchedModel().computeOperandLatency( 908 DefI, DefOpIdx, UseI, UseOpIdx)); 909 } 910 } 911 912 namespace { 913 struct FillMFMAShadowMutation : ScheduleDAGMutation { 914 const SIInstrInfo *TII; 915 916 ScheduleDAGMI *DAG; 917 918 FillMFMAShadowMutation(const SIInstrInfo *tii) : TII(tii) {} 919 920 bool isSALU(const SUnit *SU) const { 921 const MachineInstr *MI = SU->getInstr(); 922 return MI && TII->isSALU(*MI) && !MI->isTerminator(); 923 } 924 925 bool isVALU(const SUnit *SU) const { 926 const MachineInstr *MI = SU->getInstr(); 927 return MI && TII->isVALU(*MI); 928 } 929 930 // Link as many SALU instructions in chain as possible. Return the size 931 // of the chain. Links up to MaxChain instructions. 932 unsigned linkSALUChain(SUnit *From, SUnit *To, unsigned MaxChain, 933 SmallPtrSetImpl<SUnit *> &Visited) const { 934 SmallVector<SUnit *, 8> Worklist({To}); 935 unsigned Linked = 0; 936 937 while (!Worklist.empty() && MaxChain-- > 0) { 938 SUnit *SU = Worklist.pop_back_val(); 939 if (!Visited.insert(SU).second) 940 continue; 941 942 LLVM_DEBUG(dbgs() << "Inserting edge from\n" ; DAG->dumpNode(*From); 943 dbgs() << "to\n"; DAG->dumpNode(*SU); dbgs() << '\n'); 944 945 if (SU != From && From != &DAG->ExitSU && DAG->canAddEdge(SU, From)) 946 if (DAG->addEdge(SU, SDep(From, SDep::Artificial))) 947 ++Linked; 948 949 for (SDep &SI : From->Succs) { 950 SUnit *SUv = SI.getSUnit(); 951 if (SUv != From && SU != &DAG->ExitSU && isVALU(SUv) && 952 DAG->canAddEdge(SUv, SU)) 953 DAG->addEdge(SUv, SDep(SU, SDep::Artificial)); 954 } 955 956 for (SDep &SI : SU->Succs) { 957 SUnit *Succ = SI.getSUnit(); 958 if (Succ != SU && isSALU(Succ)) 959 Worklist.push_back(Succ); 960 } 961 } 962 963 return Linked; 964 } 965 966 void apply(ScheduleDAGInstrs *DAGInstrs) override { 967 const GCNSubtarget &ST = DAGInstrs->MF.getSubtarget<GCNSubtarget>(); 968 if (!ST.hasMAIInsts()) 969 return; 970 DAG = static_cast<ScheduleDAGMI*>(DAGInstrs); 971 const TargetSchedModel *TSchedModel = DAGInstrs->getSchedModel(); 972 if (!TSchedModel || DAG->SUnits.empty()) 973 return; 974 975 // Scan for MFMA long latency instructions and try to add a dependency 976 // of available SALU instructions to give them a chance to fill MFMA 977 // shadow. That is desirable to fill MFMA shadow with SALU instructions 978 // rather than VALU to prevent power consumption bursts and throttle. 979 auto LastSALU = DAG->SUnits.begin(); 980 auto E = DAG->SUnits.end(); 981 SmallPtrSet<SUnit*, 32> Visited; 982 for (SUnit &SU : DAG->SUnits) { 983 MachineInstr &MAI = *SU.getInstr(); 984 if (!TII->isMAI(MAI) || 985 MAI.getOpcode() == AMDGPU::V_ACCVGPR_WRITE_B32_e64 || 986 MAI.getOpcode() == AMDGPU::V_ACCVGPR_READ_B32_e64) 987 continue; 988 989 unsigned Lat = TSchedModel->computeInstrLatency(&MAI) - 1; 990 991 LLVM_DEBUG(dbgs() << "Found MFMA: "; DAG->dumpNode(SU); 992 dbgs() << "Need " << Lat 993 << " instructions to cover latency.\n"); 994 995 // Find up to Lat independent scalar instructions as early as 996 // possible such that they can be scheduled after this MFMA. 997 for ( ; Lat && LastSALU != E; ++LastSALU) { 998 if (Visited.count(&*LastSALU)) 999 continue; 1000 1001 if (&SU == &DAG->ExitSU || &SU == &*LastSALU || !isSALU(&*LastSALU) || 1002 !DAG->canAddEdge(&*LastSALU, &SU)) 1003 continue; 1004 1005 Lat -= linkSALUChain(&SU, &*LastSALU, Lat, Visited); 1006 } 1007 } 1008 } 1009 }; 1010 } // namespace 1011 1012 void GCNSubtarget::getPostRAMutations( 1013 std::vector<std::unique_ptr<ScheduleDAGMutation>> &Mutations) const { 1014 Mutations.push_back(std::make_unique<FillMFMAShadowMutation>(&InstrInfo)); 1015 } 1016 1017 std::unique_ptr<ScheduleDAGMutation> 1018 GCNSubtarget::createFillMFMAShadowMutation(const TargetInstrInfo *TII) const { 1019 return EnablePowerSched ? std::make_unique<FillMFMAShadowMutation>(&InstrInfo) 1020 : nullptr; 1021 } 1022 1023 unsigned GCNSubtarget::getNSAThreshold(const MachineFunction &MF) const { 1024 if (getGeneration() >= AMDGPUSubtarget::GFX12) 1025 return 0; // Not MIMG encoding. 1026 1027 if (NSAThreshold.getNumOccurrences() > 0) 1028 return std::max(NSAThreshold.getValue(), 2u); 1029 1030 int Value = MF.getFunction().getFnAttributeAsParsedInteger( 1031 "amdgpu-nsa-threshold", -1); 1032 if (Value > 0) 1033 return std::max(Value, 2); 1034 1035 return 3; 1036 } 1037 1038 const AMDGPUSubtarget &AMDGPUSubtarget::get(const MachineFunction &MF) { 1039 if (MF.getTarget().getTargetTriple().getArch() == Triple::amdgcn) 1040 return static_cast<const AMDGPUSubtarget&>(MF.getSubtarget<GCNSubtarget>()); 1041 return static_cast<const AMDGPUSubtarget &>(MF.getSubtarget<R600Subtarget>()); 1042 } 1043 1044 const AMDGPUSubtarget &AMDGPUSubtarget::get(const TargetMachine &TM, const Function &F) { 1045 if (TM.getTargetTriple().getArch() == Triple::amdgcn) 1046 return static_cast<const AMDGPUSubtarget&>(TM.getSubtarget<GCNSubtarget>(F)); 1047 return static_cast<const AMDGPUSubtarget &>( 1048 TM.getSubtarget<R600Subtarget>(F)); 1049 } 1050 1051 GCNUserSGPRUsageInfo::GCNUserSGPRUsageInfo(const Function &F, 1052 const GCNSubtarget &ST) 1053 : ST(ST) { 1054 const CallingConv::ID CC = F.getCallingConv(); 1055 const bool IsKernel = 1056 CC == CallingConv::AMDGPU_KERNEL || CC == CallingConv::SPIR_KERNEL; 1057 // FIXME: Should have analysis or something rather than attribute to detect 1058 // calls. 1059 const bool HasCalls = F.hasFnAttribute("amdgpu-calls"); 1060 // FIXME: This attribute is a hack, we just need an analysis on the function 1061 // to look for allocas. 1062 const bool HasStackObjects = F.hasFnAttribute("amdgpu-stack-objects"); 1063 1064 if (IsKernel && (!F.arg_empty() || ST.getImplicitArgNumBytes(F) != 0)) 1065 KernargSegmentPtr = true; 1066 1067 bool IsAmdHsaOrMesa = ST.isAmdHsaOrMesa(F); 1068 if (IsAmdHsaOrMesa && !ST.enableFlatScratch()) 1069 PrivateSegmentBuffer = true; 1070 else if (ST.isMesaGfxShader(F)) 1071 ImplicitBufferPtr = true; 1072 1073 if (!AMDGPU::isGraphics(CC)) { 1074 if (!F.hasFnAttribute("amdgpu-no-dispatch-ptr")) 1075 DispatchPtr = true; 1076 1077 // FIXME: Can this always be disabled with < COv5? 1078 if (!F.hasFnAttribute("amdgpu-no-queue-ptr")) 1079 QueuePtr = true; 1080 1081 if (!F.hasFnAttribute("amdgpu-no-dispatch-id")) 1082 DispatchID = true; 1083 } 1084 1085 // TODO: This could be refined a lot. The attribute is a poor way of 1086 // detecting calls or stack objects that may require it before argument 1087 // lowering. 1088 if (ST.hasFlatAddressSpace() && AMDGPU::isEntryFunctionCC(CC) && 1089 (IsAmdHsaOrMesa || ST.enableFlatScratch()) && 1090 (HasCalls || HasStackObjects || ST.enableFlatScratch()) && 1091 !ST.flatScratchIsArchitected()) { 1092 FlatScratchInit = true; 1093 } 1094 1095 if (hasImplicitBufferPtr()) 1096 NumUsedUserSGPRs += getNumUserSGPRForField(ImplicitBufferPtrID); 1097 1098 if (hasPrivateSegmentBuffer()) 1099 NumUsedUserSGPRs += getNumUserSGPRForField(PrivateSegmentBufferID); 1100 1101 if (hasDispatchPtr()) 1102 NumUsedUserSGPRs += getNumUserSGPRForField(DispatchPtrID); 1103 1104 if (hasQueuePtr()) 1105 NumUsedUserSGPRs += getNumUserSGPRForField(QueuePtrID); 1106 1107 if (hasKernargSegmentPtr()) 1108 NumUsedUserSGPRs += getNumUserSGPRForField(KernargSegmentPtrID); 1109 1110 if (hasDispatchID()) 1111 NumUsedUserSGPRs += getNumUserSGPRForField(DispatchIdID); 1112 1113 if (hasFlatScratchInit()) 1114 NumUsedUserSGPRs += getNumUserSGPRForField(FlatScratchInitID); 1115 1116 if (hasPrivateSegmentSize()) 1117 NumUsedUserSGPRs += getNumUserSGPRForField(PrivateSegmentSizeID); 1118 } 1119 1120 void GCNUserSGPRUsageInfo::allocKernargPreloadSGPRs(unsigned NumSGPRs) { 1121 assert(NumKernargPreloadSGPRs + NumSGPRs <= AMDGPU::getMaxNumUserSGPRs(ST)); 1122 NumKernargPreloadSGPRs += NumSGPRs; 1123 NumUsedUserSGPRs += NumSGPRs; 1124 } 1125 1126 unsigned GCNUserSGPRUsageInfo::getNumFreeUserSGPRs() { 1127 return AMDGPU::getMaxNumUserSGPRs(ST) - NumUsedUserSGPRs; 1128 } 1129 1130 SmallVector<unsigned> 1131 AMDGPUSubtarget::getMaxNumWorkGroups(const Function &F) const { 1132 return AMDGPU::getIntegerVecAttribute(F, "amdgpu-max-num-workgroups", 3); 1133 } 1134