LegalizeTypesGeneric.cpp revision d752e0f7e64585839cb3a458ef52456eaebbea3c
1//===-------- LegalizeTypesGeneric.cpp - Generic type legalization --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements generic type expansion and splitting for LegalizeTypes. 11// The routines here perform legalization when the details of the type (such as 12// whether it is an integer or a float) do not matter. 13// Expansion is the act of changing a computation in an illegal type to be a 14// computation in two identical registers of a smaller type. The Lo/Hi part 15// is required to be stored first in memory on little/big-endian machines. 16// Splitting is the act of changing a computation in an illegal type to be a 17// computation in two not necessarily identical registers of a smaller type. 18// There are no requirements on how the type is represented in memory. 19// 20//===----------------------------------------------------------------------===// 21 22#include "LegalizeTypes.h" 23#include "llvm/Target/TargetData.h" 24#include "llvm/CodeGen/PseudoSourceValue.h" 25using namespace llvm; 26 27//===----------------------------------------------------------------------===// 28// Generic Result Expansion. 29//===----------------------------------------------------------------------===// 30 31// These routines assume that the Lo/Hi part is stored first in memory on 32// little/big-endian machines, followed by the Hi/Lo part. This means that 33// they cannot be used as is on vectors, for which Lo is always stored first. 34void DAGTypeLegalizer::ExpandRes_MERGE_VALUES(SDNode *N, unsigned ResNo, 35 SDValue &Lo, SDValue &Hi) { 36 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo); 37 GetExpandedOp(Op, Lo, Hi); 38} 39 40void DAGTypeLegalizer::ExpandRes_BITCAST(SDNode *N, SDValue &Lo, SDValue &Hi) { 41 EVT OutVT = N->getValueType(0); 42 EVT NOutVT = TLI.getTypeToTransformTo(*DAG.getContext(), OutVT); 43 SDValue InOp = N->getOperand(0); 44 EVT InVT = InOp.getValueType(); 45 DebugLoc dl = N->getDebugLoc(); 46 47 // Handle some special cases efficiently. 48 switch (getTypeAction(InVT)) { 49 default: 50 assert(false && "Unknown type action!"); 51 case TargetLowering::TypeLegal: 52 case TargetLowering::TypePromoteInteger: 53 break; 54 case TargetLowering::TypeSoftenFloat: 55 // Convert the integer operand instead. 56 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi); 57 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo); 58 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi); 59 return; 60 case TargetLowering::TypeExpandInteger: 61 case TargetLowering::TypeExpandFloat: 62 // Convert the expanded pieces of the input. 63 GetExpandedOp(InOp, Lo, Hi); 64 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo); 65 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi); 66 return; 67 case TargetLowering::TypeSplitVector: 68 GetSplitVector(InOp, Lo, Hi); 69 if (TLI.isBigEndian()) 70 std::swap(Lo, Hi); 71 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo); 72 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi); 73 return; 74 case TargetLowering::TypeScalarizeVector: 75 // Convert the element instead. 76 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi); 77 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo); 78 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi); 79 return; 80 case TargetLowering::TypeWidenVector: { 81 assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BITCAST"); 82 InOp = GetWidenedVector(InOp); 83 EVT InNVT = EVT::getVectorVT(*DAG.getContext(), InVT.getVectorElementType(), 84 InVT.getVectorNumElements()/2); 85 Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, InNVT, InOp, 86 DAG.getIntPtrConstant(0)); 87 Hi = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, InNVT, InOp, 88 DAG.getIntPtrConstant(InNVT.getVectorNumElements())); 89 if (TLI.isBigEndian()) 90 std::swap(Lo, Hi); 91 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo); 92 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi); 93 return; 94 } 95 } 96 97 if (InVT.isVector() && OutVT.isInteger()) { 98 // Handle cases like i64 = BITCAST v1i64 on x86, where the operand 99 // is legal but the result is not. 100 EVT NVT = EVT::getVectorVT(*DAG.getContext(), NOutVT, 2); 101 102 if (isTypeLegal(NVT)) { 103 SDValue CastInOp = DAG.getNode(ISD::BITCAST, dl, NVT, InOp); 104 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NOutVT, CastInOp, 105 DAG.getIntPtrConstant(0)); 106 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NOutVT, CastInOp, 107 DAG.getIntPtrConstant(1)); 108 109 if (TLI.isBigEndian()) 110 std::swap(Lo, Hi); 111 112 return; 113 } 114 } 115 116 // Lower the bit-convert to a store/load from the stack. 117 assert(NOutVT.isByteSized() && "Expanded type not byte sized!"); 118 119 // Create the stack frame object. Make sure it is aligned for both 120 // the source and expanded destination types. 121 unsigned Alignment = 122 TLI.getTargetData()->getPrefTypeAlignment(NOutVT. 123 getTypeForEVT(*DAG.getContext())); 124 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment); 125 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex(); 126 MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI); 127 128 // Emit a store to the stack slot. 129 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo, 130 false, false, 0); 131 132 // Load the first half from the stack slot. 133 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo, 134 false, false, false, 0); 135 136 // Increment the pointer to the other half. 137 unsigned IncrementSize = NOutVT.getSizeInBits() / 8; 138 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr, 139 DAG.getIntPtrConstant(IncrementSize)); 140 141 // Load the second half from the stack slot. 142 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr, 143 PtrInfo.getWithOffset(IncrementSize), false, 144 false, false, MinAlign(Alignment, IncrementSize)); 145 146 // Handle endianness of the load. 147 if (TLI.isBigEndian()) 148 std::swap(Lo, Hi); 149} 150 151void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo, 152 SDValue &Hi) { 153 // Return the operands. 154 Lo = N->getOperand(0); 155 Hi = N->getOperand(1); 156} 157 158void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo, 159 SDValue &Hi) { 160 GetExpandedOp(N->getOperand(0), Lo, Hi); 161 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? 162 Hi : Lo; 163 164 assert(Part.getValueType() == N->getValueType(0) && 165 "Type twice as big as expanded type not itself expanded!"); 166 167 GetPairElements(Part, Lo, Hi); 168} 169 170void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo, 171 SDValue &Hi) { 172 SDValue OldVec = N->getOperand(0); 173 unsigned OldElts = OldVec.getValueType().getVectorNumElements(); 174 DebugLoc dl = N->getDebugLoc(); 175 176 // Convert to a vector of the expanded element type, for example 177 // <3 x i64> -> <6 x i32>. 178 EVT OldVT = N->getValueType(0); 179 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT); 180 181 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl, 182 EVT::getVectorVT(*DAG.getContext(), 183 NewVT, 2*OldElts), 184 OldVec); 185 186 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector. 187 SDValue Idx = N->getOperand(1); 188 189 // Make sure the type of Idx is big enough to hold the new values. 190 if (Idx.getValueType().bitsLT(TLI.getPointerTy())) 191 Idx = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Idx); 192 193 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 194 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 195 196 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, 197 DAG.getConstant(1, Idx.getValueType())); 198 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 199 200 if (TLI.isBigEndian()) 201 std::swap(Lo, Hi); 202} 203 204void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo, 205 SDValue &Hi) { 206 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!"); 207 DebugLoc dl = N->getDebugLoc(); 208 209 LoadSDNode *LD = cast<LoadSDNode>(N); 210 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), LD->getValueType(0)); 211 SDValue Chain = LD->getChain(); 212 SDValue Ptr = LD->getBasePtr(); 213 unsigned Alignment = LD->getAlignment(); 214 bool isVolatile = LD->isVolatile(); 215 bool isNonTemporal = LD->isNonTemporal(); 216 bool isInvariant = LD->isInvariant(); 217 218 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 219 220 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(), 221 isVolatile, isNonTemporal, isInvariant, Alignment); 222 223 // Increment the pointer to the other half. 224 unsigned IncrementSize = NVT.getSizeInBits() / 8; 225 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 226 DAG.getIntPtrConstant(IncrementSize)); 227 Hi = DAG.getLoad(NVT, dl, Chain, Ptr, 228 LD->getPointerInfo().getWithOffset(IncrementSize), 229 isVolatile, isNonTemporal, isInvariant, 230 MinAlign(Alignment, IncrementSize)); 231 232 // Build a factor node to remember that this load is independent of the 233 // other one. 234 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1), 235 Hi.getValue(1)); 236 237 // Handle endianness of the load. 238 if (TLI.isBigEndian()) 239 std::swap(Lo, Hi); 240 241 // Modified the chain - switch anything that used the old chain to use 242 // the new one. 243 ReplaceValueWith(SDValue(N, 1), Chain); 244} 245 246void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) { 247 EVT OVT = N->getValueType(0); 248 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), OVT); 249 SDValue Chain = N->getOperand(0); 250 SDValue Ptr = N->getOperand(1); 251 DebugLoc dl = N->getDebugLoc(); 252 const unsigned Align = N->getConstantOperandVal(3); 253 254 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2), Align); 255 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2), 0); 256 257 // Handle endianness of the load. 258 if (TLI.isBigEndian()) 259 std::swap(Lo, Hi); 260 261 // Modified the chain - switch anything that used the old chain to use 262 // the new one. 263 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1)); 264} 265 266 267//===--------------------------------------------------------------------===// 268// Generic Operand Expansion. 269//===--------------------------------------------------------------------===// 270 271SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) { 272 DebugLoc dl = N->getDebugLoc(); 273 if (N->getValueType(0).isVector()) { 274 // An illegal expanding type is being converted to a legal vector type. 275 // Make a two element vector out of the expanded parts and convert that 276 // instead, but only if the new vector type is legal (otherwise there 277 // is no point, and it might create expansion loops). For example, on 278 // x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32. 279 EVT OVT = N->getOperand(0).getValueType(); 280 EVT NVT = EVT::getVectorVT(*DAG.getContext(), 281 TLI.getTypeToTransformTo(*DAG.getContext(), OVT), 282 2); 283 284 if (isTypeLegal(NVT)) { 285 SDValue Parts[2]; 286 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]); 287 288 if (TLI.isBigEndian()) 289 std::swap(Parts[0], Parts[1]); 290 291 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2); 292 return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec); 293 } 294 } 295 296 // Otherwise, store to a temporary and load out again as the new type. 297 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0)); 298} 299 300SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) { 301 // The vector type is legal but the element type needs expansion. 302 EVT VecVT = N->getValueType(0); 303 unsigned NumElts = VecVT.getVectorNumElements(); 304 EVT OldVT = N->getOperand(0).getValueType(); 305 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT); 306 DebugLoc dl = N->getDebugLoc(); 307 308 assert(OldVT == VecVT.getVectorElementType() && 309 "BUILD_VECTOR operand type doesn't match vector element type!"); 310 311 // Build a vector of twice the length out of the expanded elements. 312 // For example <3 x i64> -> <6 x i32>. 313 std::vector<SDValue> NewElts; 314 NewElts.reserve(NumElts*2); 315 316 for (unsigned i = 0; i < NumElts; ++i) { 317 SDValue Lo, Hi; 318 GetExpandedOp(N->getOperand(i), Lo, Hi); 319 if (TLI.isBigEndian()) 320 std::swap(Lo, Hi); 321 NewElts.push_back(Lo); 322 NewElts.push_back(Hi); 323 } 324 325 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl, 326 EVT::getVectorVT(*DAG.getContext(), 327 NewVT, NewElts.size()), 328 &NewElts[0], NewElts.size()); 329 330 // Convert the new vector to the old vector type. 331 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec); 332} 333 334SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) { 335 SDValue Lo, Hi; 336 GetExpandedOp(N->getOperand(0), Lo, Hi); 337 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo; 338} 339 340SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) { 341 // The vector type is legal but the element type needs expansion. 342 EVT VecVT = N->getValueType(0); 343 unsigned NumElts = VecVT.getVectorNumElements(); 344 DebugLoc dl = N->getDebugLoc(); 345 346 SDValue Val = N->getOperand(1); 347 EVT OldEVT = Val.getValueType(); 348 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT); 349 350 assert(OldEVT == VecVT.getVectorElementType() && 351 "Inserted element type doesn't match vector element type!"); 352 353 // Bitconvert to a vector of twice the length with elements of the expanded 354 // type, insert the expanded vector elements, and then convert back. 355 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2); 356 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl, 357 NewVecVT, N->getOperand(0)); 358 359 SDValue Lo, Hi; 360 GetExpandedOp(Val, Lo, Hi); 361 if (TLI.isBigEndian()) 362 std::swap(Lo, Hi); 363 364 SDValue Idx = N->getOperand(2); 365 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 366 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx); 367 Idx = DAG.getNode(ISD::ADD, dl, 368 Idx.getValueType(), Idx, DAG.getIntPtrConstant(1)); 369 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx); 370 371 // Convert the new vector to the old vector type. 372 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec); 373} 374 375SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) { 376 DebugLoc dl = N->getDebugLoc(); 377 EVT VT = N->getValueType(0); 378 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() && 379 "SCALAR_TO_VECTOR operand type doesn't match vector element type!"); 380 unsigned NumElts = VT.getVectorNumElements(); 381 SmallVector<SDValue, 16> Ops(NumElts); 382 Ops[0] = N->getOperand(0); 383 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType()); 384 for (unsigned i = 1; i < NumElts; ++i) 385 Ops[i] = UndefVal; 386 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts); 387} 388 389SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) { 390 assert(ISD::isNormalStore(N) && "This routine only for normal stores!"); 391 assert(OpNo == 1 && "Can only expand the stored value so far"); 392 DebugLoc dl = N->getDebugLoc(); 393 394 StoreSDNode *St = cast<StoreSDNode>(N); 395 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), 396 St->getValue().getValueType()); 397 SDValue Chain = St->getChain(); 398 SDValue Ptr = St->getBasePtr(); 399 unsigned Alignment = St->getAlignment(); 400 bool isVolatile = St->isVolatile(); 401 bool isNonTemporal = St->isNonTemporal(); 402 403 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 404 unsigned IncrementSize = NVT.getSizeInBits() / 8; 405 406 SDValue Lo, Hi; 407 GetExpandedOp(St->getValue(), Lo, Hi); 408 409 if (TLI.isBigEndian()) 410 std::swap(Lo, Hi); 411 412 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(), 413 isVolatile, isNonTemporal, Alignment); 414 415 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 416 DAG.getIntPtrConstant(IncrementSize)); 417 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!"); 418 Hi = DAG.getStore(Chain, dl, Hi, Ptr, 419 St->getPointerInfo().getWithOffset(IncrementSize), 420 isVolatile, isNonTemporal, 421 MinAlign(Alignment, IncrementSize)); 422 423 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi); 424} 425 426 427//===--------------------------------------------------------------------===// 428// Generic Result Splitting. 429//===--------------------------------------------------------------------===// 430 431// Be careful to make no assumptions about which of Lo/Hi is stored first in 432// memory (for vectors it is always Lo first followed by Hi in the following 433// bytes; for integers and floats it is Lo first if and only if the machine is 434// little-endian). 435 436void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, unsigned ResNo, 437 SDValue &Lo, SDValue &Hi) { 438 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo); 439 GetSplitOp(Op, Lo, Hi); 440} 441 442void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo, 443 SDValue &Hi) { 444 SDValue LL, LH, RL, RH, CL, CH; 445 DebugLoc dl = N->getDebugLoc(); 446 GetSplitOp(N->getOperand(1), LL, LH); 447 GetSplitOp(N->getOperand(2), RL, RH); 448 449 SDValue Cond = N->getOperand(0); 450 CL = CH = Cond; 451 if (Cond.getValueType().isVector()) { 452 assert(Cond.getValueType().getVectorElementType() == MVT::i1 && 453 "Condition legalized before result?"); 454 unsigned NumElements = Cond.getValueType().getVectorNumElements(); 455 EVT VCondTy = EVT::getVectorVT(*DAG.getContext(), MVT::i1, NumElements / 2); 456 CL = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VCondTy, Cond, 457 DAG.getIntPtrConstant(0)); 458 CH = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VCondTy, Cond, 459 DAG.getIntPtrConstant(NumElements / 2)); 460 } 461 462 Lo = DAG.getNode(N->getOpcode(), dl, LL.getValueType(), CL, LL, RL); 463 Hi = DAG.getNode(N->getOpcode(), dl, LH.getValueType(), CH, LH, RH); 464} 465 466void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo, 467 SDValue &Hi) { 468 SDValue LL, LH, RL, RH; 469 DebugLoc dl = N->getDebugLoc(); 470 GetSplitOp(N->getOperand(2), LL, LH); 471 GetSplitOp(N->getOperand(3), RL, RH); 472 473 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0), 474 N->getOperand(1), LL, RL, N->getOperand(4)); 475 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0), 476 N->getOperand(1), LH, RH, N->getOperand(4)); 477} 478 479void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) { 480 EVT LoVT, HiVT; 481 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT); 482 Lo = DAG.getUNDEF(LoVT); 483 Hi = DAG.getUNDEF(HiVT); 484} 485