LegalizeTypesGeneric.cpp revision 223017
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. 34 35void DAGTypeLegalizer::ExpandRes_BITCAST(SDNode *N, SDValue &Lo, SDValue &Hi) { 36 EVT OutVT = N->getValueType(0); 37 EVT NOutVT = TLI.getTypeToTransformTo(*DAG.getContext(), OutVT); 38 SDValue InOp = N->getOperand(0); 39 EVT InVT = InOp.getValueType(); 40 DebugLoc dl = N->getDebugLoc(); 41 42 // Handle some special cases efficiently. 43 switch (getTypeAction(InVT)) { 44 default: 45 assert(false && "Unknown type action!"); 46 case TargetLowering::TypeLegal: 47 case TargetLowering::TypePromoteInteger: 48 break; 49 case TargetLowering::TypeSoftenFloat: 50 // Convert the integer operand instead. 51 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi); 52 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo); 53 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi); 54 return; 55 case TargetLowering::TypeExpandInteger: 56 case TargetLowering::TypeExpandFloat: 57 // Convert the expanded pieces of the input. 58 GetExpandedOp(InOp, Lo, Hi); 59 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo); 60 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi); 61 return; 62 case TargetLowering::TypeSplitVector: 63 GetSplitVector(InOp, Lo, Hi); 64 if (TLI.isBigEndian()) 65 std::swap(Lo, Hi); 66 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo); 67 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi); 68 return; 69 case TargetLowering::TypeScalarizeVector: 70 // Convert the element instead. 71 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi); 72 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo); 73 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi); 74 return; 75 case TargetLowering::TypeWidenVector: { 76 assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BITCAST"); 77 InOp = GetWidenedVector(InOp); 78 EVT InNVT = EVT::getVectorVT(*DAG.getContext(), InVT.getVectorElementType(), 79 InVT.getVectorNumElements()/2); 80 Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, InNVT, InOp, 81 DAG.getIntPtrConstant(0)); 82 Hi = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, InNVT, InOp, 83 DAG.getIntPtrConstant(InNVT.getVectorNumElements())); 84 if (TLI.isBigEndian()) 85 std::swap(Lo, Hi); 86 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo); 87 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi); 88 return; 89 } 90 } 91 92 if (InVT.isVector() && OutVT.isInteger()) { 93 // Handle cases like i64 = BITCAST v1i64 on x86, where the operand 94 // is legal but the result is not. 95 EVT NVT = EVT::getVectorVT(*DAG.getContext(), NOutVT, 2); 96 97 if (isTypeLegal(NVT)) { 98 SDValue CastInOp = DAG.getNode(ISD::BITCAST, dl, NVT, InOp); 99 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NOutVT, CastInOp, 100 DAG.getIntPtrConstant(0)); 101 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NOutVT, CastInOp, 102 DAG.getIntPtrConstant(1)); 103 104 if (TLI.isBigEndian()) 105 std::swap(Lo, Hi); 106 107 return; 108 } 109 } 110 111 // Lower the bit-convert to a store/load from the stack. 112 assert(NOutVT.isByteSized() && "Expanded type not byte sized!"); 113 114 // Create the stack frame object. Make sure it is aligned for both 115 // the source and expanded destination types. 116 unsigned Alignment = 117 TLI.getTargetData()->getPrefTypeAlignment(NOutVT. 118 getTypeForEVT(*DAG.getContext())); 119 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment); 120 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex(); 121 MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI); 122 123 // Emit a store to the stack slot. 124 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo, 125 false, false, 0); 126 127 // Load the first half from the stack slot. 128 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo, false, false, 0); 129 130 // Increment the pointer to the other half. 131 unsigned IncrementSize = NOutVT.getSizeInBits() / 8; 132 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr, 133 DAG.getIntPtrConstant(IncrementSize)); 134 135 // Load the second half from the stack slot. 136 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr, 137 PtrInfo.getWithOffset(IncrementSize), false, 138 false, MinAlign(Alignment, IncrementSize)); 139 140 // Handle endianness of the load. 141 if (TLI.isBigEndian()) 142 std::swap(Lo, Hi); 143} 144 145void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo, 146 SDValue &Hi) { 147 // Return the operands. 148 Lo = N->getOperand(0); 149 Hi = N->getOperand(1); 150} 151 152void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo, 153 SDValue &Hi) { 154 GetExpandedOp(N->getOperand(0), Lo, Hi); 155 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? 156 Hi : Lo; 157 158 assert(Part.getValueType() == N->getValueType(0) && 159 "Type twice as big as expanded type not itself expanded!"); 160 161 GetPairElements(Part, Lo, Hi); 162} 163 164void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo, 165 SDValue &Hi) { 166 SDValue OldVec = N->getOperand(0); 167 unsigned OldElts = OldVec.getValueType().getVectorNumElements(); 168 DebugLoc dl = N->getDebugLoc(); 169 170 // Convert to a vector of the expanded element type, for example 171 // <3 x i64> -> <6 x i32>. 172 EVT OldVT = N->getValueType(0); 173 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT); 174 175 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl, 176 EVT::getVectorVT(*DAG.getContext(), 177 NewVT, 2*OldElts), 178 OldVec); 179 180 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector. 181 SDValue Idx = N->getOperand(1); 182 183 // Make sure the type of Idx is big enough to hold the new values. 184 if (Idx.getValueType().bitsLT(TLI.getPointerTy())) 185 Idx = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Idx); 186 187 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 188 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 189 190 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, 191 DAG.getConstant(1, Idx.getValueType())); 192 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 193 194 if (TLI.isBigEndian()) 195 std::swap(Lo, Hi); 196} 197 198void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo, 199 SDValue &Hi) { 200 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!"); 201 DebugLoc dl = N->getDebugLoc(); 202 203 LoadSDNode *LD = cast<LoadSDNode>(N); 204 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), LD->getValueType(0)); 205 SDValue Chain = LD->getChain(); 206 SDValue Ptr = LD->getBasePtr(); 207 unsigned Alignment = LD->getAlignment(); 208 bool isVolatile = LD->isVolatile(); 209 bool isNonTemporal = LD->isNonTemporal(); 210 211 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 212 213 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(), 214 isVolatile, isNonTemporal, Alignment); 215 216 // Increment the pointer to the other half. 217 unsigned IncrementSize = NVT.getSizeInBits() / 8; 218 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 219 DAG.getIntPtrConstant(IncrementSize)); 220 Hi = DAG.getLoad(NVT, dl, Chain, Ptr, 221 LD->getPointerInfo().getWithOffset(IncrementSize), 222 isVolatile, isNonTemporal, 223 MinAlign(Alignment, IncrementSize)); 224 225 // Build a factor node to remember that this load is independent of the 226 // other one. 227 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1), 228 Hi.getValue(1)); 229 230 // Handle endianness of the load. 231 if (TLI.isBigEndian()) 232 std::swap(Lo, Hi); 233 234 // Modified the chain - switch anything that used the old chain to use 235 // the new one. 236 ReplaceValueWith(SDValue(N, 1), Chain); 237} 238 239void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) { 240 EVT OVT = N->getValueType(0); 241 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), OVT); 242 SDValue Chain = N->getOperand(0); 243 SDValue Ptr = N->getOperand(1); 244 DebugLoc dl = N->getDebugLoc(); 245 const unsigned Align = N->getConstantOperandVal(3); 246 247 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2), Align); 248 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2), 0); 249 250 // Handle endianness of the load. 251 if (TLI.isBigEndian()) 252 std::swap(Lo, Hi); 253 254 // Modified the chain - switch anything that used the old chain to use 255 // the new one. 256 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1)); 257} 258 259 260//===--------------------------------------------------------------------===// 261// Generic Operand Expansion. 262//===--------------------------------------------------------------------===// 263 264SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) { 265 DebugLoc dl = N->getDebugLoc(); 266 if (N->getValueType(0).isVector()) { 267 // An illegal expanding type is being converted to a legal vector type. 268 // Make a two element vector out of the expanded parts and convert that 269 // instead, but only if the new vector type is legal (otherwise there 270 // is no point, and it might create expansion loops). For example, on 271 // x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32. 272 EVT OVT = N->getOperand(0).getValueType(); 273 EVT NVT = EVT::getVectorVT(*DAG.getContext(), 274 TLI.getTypeToTransformTo(*DAG.getContext(), OVT), 275 2); 276 277 if (isTypeLegal(NVT)) { 278 SDValue Parts[2]; 279 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]); 280 281 if (TLI.isBigEndian()) 282 std::swap(Parts[0], Parts[1]); 283 284 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2); 285 return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec); 286 } 287 } 288 289 // Otherwise, store to a temporary and load out again as the new type. 290 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0)); 291} 292 293SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) { 294 // The vector type is legal but the element type needs expansion. 295 EVT VecVT = N->getValueType(0); 296 unsigned NumElts = VecVT.getVectorNumElements(); 297 EVT OldVT = N->getOperand(0).getValueType(); 298 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT); 299 DebugLoc dl = N->getDebugLoc(); 300 301 assert(OldVT == VecVT.getVectorElementType() && 302 "BUILD_VECTOR operand type doesn't match vector element type!"); 303 304 // Build a vector of twice the length out of the expanded elements. 305 // For example <3 x i64> -> <6 x i32>. 306 std::vector<SDValue> NewElts; 307 NewElts.reserve(NumElts*2); 308 309 for (unsigned i = 0; i < NumElts; ++i) { 310 SDValue Lo, Hi; 311 GetExpandedOp(N->getOperand(i), Lo, Hi); 312 if (TLI.isBigEndian()) 313 std::swap(Lo, Hi); 314 NewElts.push_back(Lo); 315 NewElts.push_back(Hi); 316 } 317 318 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl, 319 EVT::getVectorVT(*DAG.getContext(), 320 NewVT, NewElts.size()), 321 &NewElts[0], NewElts.size()); 322 323 // Convert the new vector to the old vector type. 324 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec); 325} 326 327SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) { 328 SDValue Lo, Hi; 329 GetExpandedOp(N->getOperand(0), Lo, Hi); 330 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo; 331} 332 333SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) { 334 // The vector type is legal but the element type needs expansion. 335 EVT VecVT = N->getValueType(0); 336 unsigned NumElts = VecVT.getVectorNumElements(); 337 DebugLoc dl = N->getDebugLoc(); 338 339 SDValue Val = N->getOperand(1); 340 EVT OldEVT = Val.getValueType(); 341 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT); 342 343 assert(OldEVT == VecVT.getVectorElementType() && 344 "Inserted element type doesn't match vector element type!"); 345 346 // Bitconvert to a vector of twice the length with elements of the expanded 347 // type, insert the expanded vector elements, and then convert back. 348 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2); 349 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl, 350 NewVecVT, N->getOperand(0)); 351 352 SDValue Lo, Hi; 353 GetExpandedOp(Val, Lo, Hi); 354 if (TLI.isBigEndian()) 355 std::swap(Lo, Hi); 356 357 SDValue Idx = N->getOperand(2); 358 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 359 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx); 360 Idx = DAG.getNode(ISD::ADD, dl, 361 Idx.getValueType(), Idx, DAG.getIntPtrConstant(1)); 362 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx); 363 364 // Convert the new vector to the old vector type. 365 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec); 366} 367 368SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) { 369 DebugLoc dl = N->getDebugLoc(); 370 EVT VT = N->getValueType(0); 371 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() && 372 "SCALAR_TO_VECTOR operand type doesn't match vector element type!"); 373 unsigned NumElts = VT.getVectorNumElements(); 374 SmallVector<SDValue, 16> Ops(NumElts); 375 Ops[0] = N->getOperand(0); 376 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType()); 377 for (unsigned i = 1; i < NumElts; ++i) 378 Ops[i] = UndefVal; 379 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts); 380} 381 382SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) { 383 assert(ISD::isNormalStore(N) && "This routine only for normal stores!"); 384 assert(OpNo == 1 && "Can only expand the stored value so far"); 385 DebugLoc dl = N->getDebugLoc(); 386 387 StoreSDNode *St = cast<StoreSDNode>(N); 388 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), 389 St->getValue().getValueType()); 390 SDValue Chain = St->getChain(); 391 SDValue Ptr = St->getBasePtr(); 392 unsigned Alignment = St->getAlignment(); 393 bool isVolatile = St->isVolatile(); 394 bool isNonTemporal = St->isNonTemporal(); 395 396 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 397 unsigned IncrementSize = NVT.getSizeInBits() / 8; 398 399 SDValue Lo, Hi; 400 GetExpandedOp(St->getValue(), Lo, Hi); 401 402 if (TLI.isBigEndian()) 403 std::swap(Lo, Hi); 404 405 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(), 406 isVolatile, isNonTemporal, Alignment); 407 408 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 409 DAG.getIntPtrConstant(IncrementSize)); 410 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!"); 411 Hi = DAG.getStore(Chain, dl, Hi, Ptr, 412 St->getPointerInfo().getWithOffset(IncrementSize), 413 isVolatile, isNonTemporal, 414 MinAlign(Alignment, IncrementSize)); 415 416 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi); 417} 418 419 420//===--------------------------------------------------------------------===// 421// Generic Result Splitting. 422//===--------------------------------------------------------------------===// 423 424// Be careful to make no assumptions about which of Lo/Hi is stored first in 425// memory (for vectors it is always Lo first followed by Hi in the following 426// bytes; for integers and floats it is Lo first if and only if the machine is 427// little-endian). 428 429void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, 430 SDValue &Lo, SDValue &Hi) { 431 // A MERGE_VALUES node can produce any number of values. We know that the 432 // first illegal one needs to be expanded into Lo/Hi. 433 unsigned i; 434 435 // The string of legal results gets turned into input operands, which have 436 // the same type. 437 for (i = 0; isTypeLegal(N->getValueType(i)); ++i) 438 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 439 440 // The first illegal result must be the one that needs to be expanded. 441 GetSplitOp(N->getOperand(i), Lo, Hi); 442 443 // Legalize the rest of the results into the input operands whether they are 444 // legal or not. 445 unsigned e = N->getNumValues(); 446 for (++i; i != e; ++i) 447 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 448} 449 450void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo, 451 SDValue &Hi) { 452 SDValue LL, LH, RL, RH; 453 DebugLoc dl = N->getDebugLoc(); 454 GetSplitOp(N->getOperand(1), LL, LH); 455 GetSplitOp(N->getOperand(2), RL, RH); 456 457 SDValue Cond = N->getOperand(0); 458 Lo = DAG.getNode(ISD::SELECT, dl, LL.getValueType(), Cond, LL, RL); 459 Hi = DAG.getNode(ISD::SELECT, dl, LH.getValueType(), Cond, LH, RH); 460} 461 462void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo, 463 SDValue &Hi) { 464 SDValue LL, LH, RL, RH; 465 DebugLoc dl = N->getDebugLoc(); 466 GetSplitOp(N->getOperand(2), LL, LH); 467 GetSplitOp(N->getOperand(3), RL, RH); 468 469 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0), 470 N->getOperand(1), LL, RL, N->getOperand(4)); 471 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0), 472 N->getOperand(1), LH, RH, N->getOperand(4)); 473} 474 475void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) { 476 EVT LoVT, HiVT; 477 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT); 478 Lo = DAG.getUNDEF(LoVT); 479 Hi = DAG.getUNDEF(HiVT); 480} 481