LegalizeTypesGeneric.cpp revision ecf42c4720aba6ee315d0166045c54187ac2de4d
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_BIT_CONVERT(SDNode *N, SDValue &Lo, 36 SDValue &Hi) { 37 EVT OutVT = N->getValueType(0); 38 EVT NOutVT = TLI.getTypeToTransformTo(*DAG.getContext(), OutVT); 39 SDValue InOp = N->getOperand(0); 40 EVT InVT = InOp.getValueType(); 41 DebugLoc dl = N->getDebugLoc(); 42 43 // Handle some special cases efficiently. 44 switch (getTypeAction(InVT)) { 45 default: 46 assert(false && "Unknown type action!"); 47 case Legal: 48 case PromoteInteger: 49 break; 50 case SoftenFloat: 51 // Convert the integer operand instead. 52 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi); 53 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo); 54 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi); 55 return; 56 case ExpandInteger: 57 case ExpandFloat: 58 // Convert the expanded pieces of the input. 59 GetExpandedOp(InOp, Lo, Hi); 60 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo); 61 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi); 62 return; 63 case SplitVector: 64 GetSplitVector(InOp, Lo, Hi); 65 if (TLI.isBigEndian()) 66 std::swap(Lo, Hi); 67 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo); 68 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi); 69 return; 70 case ScalarizeVector: 71 // Convert the element instead. 72 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi); 73 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo); 74 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi); 75 return; 76 case WidenVector: { 77 assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BIT_CONVERT"); 78 InOp = GetWidenedVector(InOp); 79 EVT InNVT = EVT::getVectorVT(*DAG.getContext(), InVT.getVectorElementType(), 80 InVT.getVectorNumElements()/2); 81 Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, InNVT, InOp, 82 DAG.getIntPtrConstant(0)); 83 Hi = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, InNVT, InOp, 84 DAG.getIntPtrConstant(InNVT.getVectorNumElements())); 85 if (TLI.isBigEndian()) 86 std::swap(Lo, Hi); 87 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo); 88 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi); 89 return; 90 } 91 } 92 93 if (InVT.isVector() && OutVT.isInteger()) { 94 // Handle cases like i64 = BIT_CONVERT v1i64 on x86, where the operand 95 // is legal but the result is not. 96 EVT NVT = EVT::getVectorVT(*DAG.getContext(), NOutVT, 2); 97 98 if (isTypeLegal(NVT)) { 99 SDValue CastInOp = DAG.getNode(ISD::BIT_CONVERT, dl, NVT, InOp); 100 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NOutVT, CastInOp, 101 DAG.getIntPtrConstant(0)); 102 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NOutVT, CastInOp, 103 DAG.getIntPtrConstant(1)); 104 105 if (TLI.isBigEndian()) 106 std::swap(Lo, Hi); 107 108 return; 109 } 110 } 111 112 // Lower the bit-convert to a store/load from the stack. 113 assert(NOutVT.isByteSized() && "Expanded type not byte sized!"); 114 115 // Create the stack frame object. Make sure it is aligned for both 116 // the source and expanded destination types. 117 unsigned Alignment = 118 TLI.getTargetData()->getPrefTypeAlignment(NOutVT. 119 getTypeForEVT(*DAG.getContext())); 120 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment); 121 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex(); 122 MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI); 123 124 // Emit a store to the stack slot. 125 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo, 126 false, false, 0); 127 128 // Load the first half from the stack slot. 129 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo, false, false, 0); 130 131 // Increment the pointer to the other half. 132 unsigned IncrementSize = NOutVT.getSizeInBits() / 8; 133 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr, 134 DAG.getIntPtrConstant(IncrementSize)); 135 136 // Load the second half from the stack slot. 137 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr, 138 PtrInfo.getWithOffset(IncrementSize), false, 139 false, MinAlign(Alignment, IncrementSize)); 140 141 // Handle endianness of the load. 142 if (TLI.isBigEndian()) 143 std::swap(Lo, Hi); 144} 145 146void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo, 147 SDValue &Hi) { 148 // Return the operands. 149 Lo = N->getOperand(0); 150 Hi = N->getOperand(1); 151} 152 153void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo, 154 SDValue &Hi) { 155 GetExpandedOp(N->getOperand(0), Lo, Hi); 156 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? 157 Hi : Lo; 158 159 assert(Part.getValueType() == N->getValueType(0) && 160 "Type twice as big as expanded type not itself expanded!"); 161 162 GetPairElements(Part, Lo, Hi); 163} 164 165void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo, 166 SDValue &Hi) { 167 SDValue OldVec = N->getOperand(0); 168 unsigned OldElts = OldVec.getValueType().getVectorNumElements(); 169 DebugLoc dl = N->getDebugLoc(); 170 171 // Convert to a vector of the expanded element type, for example 172 // <3 x i64> -> <6 x i32>. 173 EVT OldVT = N->getValueType(0); 174 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT); 175 176 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl, 177 EVT::getVectorVT(*DAG.getContext(), 178 NewVT, 2*OldElts), 179 OldVec); 180 181 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector. 182 SDValue Idx = N->getOperand(1); 183 184 // Make sure the type of Idx is big enough to hold the new values. 185 if (Idx.getValueType().bitsLT(TLI.getPointerTy())) 186 Idx = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Idx); 187 188 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 189 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 190 191 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, 192 DAG.getConstant(1, Idx.getValueType())); 193 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 194 195 if (TLI.isBigEndian()) 196 std::swap(Lo, Hi); 197} 198 199void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo, 200 SDValue &Hi) { 201 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!"); 202 DebugLoc dl = N->getDebugLoc(); 203 204 LoadSDNode *LD = cast<LoadSDNode>(N); 205 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), LD->getValueType(0)); 206 SDValue Chain = LD->getChain(); 207 SDValue Ptr = LD->getBasePtr(); 208 unsigned Alignment = LD->getAlignment(); 209 bool isVolatile = LD->isVolatile(); 210 bool isNonTemporal = LD->isNonTemporal(); 211 212 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 213 214 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(), 215 isVolatile, isNonTemporal, Alignment); 216 217 // Increment the pointer to the other half. 218 unsigned IncrementSize = NVT.getSizeInBits() / 8; 219 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 220 DAG.getIntPtrConstant(IncrementSize)); 221 Hi = DAG.getLoad(NVT, dl, Chain, Ptr, 222 LD->getPointerInfo().getWithOffset(IncrementSize), 223 isVolatile, isNonTemporal, 224 MinAlign(Alignment, IncrementSize)); 225 226 // Build a factor node to remember that this load is independent of the 227 // other one. 228 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1), 229 Hi.getValue(1)); 230 231 // Handle endianness of the load. 232 if (TLI.isBigEndian()) 233 std::swap(Lo, Hi); 234 235 // Modified the chain - switch anything that used the old chain to use 236 // the new one. 237 ReplaceValueWith(SDValue(N, 1), Chain); 238} 239 240void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) { 241 EVT OVT = N->getValueType(0); 242 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), OVT); 243 SDValue Chain = N->getOperand(0); 244 SDValue Ptr = N->getOperand(1); 245 DebugLoc dl = N->getDebugLoc(); 246 const unsigned Align = N->getConstantOperandVal(3); 247 248 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2), Align); 249 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2), 0); 250 251 // Handle endianness of the load. 252 if (TLI.isBigEndian()) 253 std::swap(Lo, Hi); 254 255 // Modified the chain - switch anything that used the old chain to use 256 // the new one. 257 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1)); 258} 259 260 261//===--------------------------------------------------------------------===// 262// Generic Operand Expansion. 263//===--------------------------------------------------------------------===// 264 265SDValue DAGTypeLegalizer::ExpandOp_BIT_CONVERT(SDNode *N) { 266 DebugLoc dl = N->getDebugLoc(); 267 if (N->getValueType(0).isVector()) { 268 // An illegal expanding type is being converted to a legal vector type. 269 // Make a two element vector out of the expanded parts and convert that 270 // instead, but only if the new vector type is legal (otherwise there 271 // is no point, and it might create expansion loops). For example, on 272 // x86 this turns v1i64 = BIT_CONVERT i64 into v1i64 = BIT_CONVERT v2i32. 273 EVT OVT = N->getOperand(0).getValueType(); 274 EVT NVT = EVT::getVectorVT(*DAG.getContext(), 275 TLI.getTypeToTransformTo(*DAG.getContext(), OVT), 276 2); 277 278 if (isTypeLegal(NVT)) { 279 SDValue Parts[2]; 280 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]); 281 282 if (TLI.isBigEndian()) 283 std::swap(Parts[0], Parts[1]); 284 285 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2); 286 return DAG.getNode(ISD::BIT_CONVERT, dl, N->getValueType(0), Vec); 287 } 288 } 289 290 // Otherwise, store to a temporary and load out again as the new type. 291 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0)); 292} 293 294SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) { 295 // The vector type is legal but the element type needs expansion. 296 EVT VecVT = N->getValueType(0); 297 unsigned NumElts = VecVT.getVectorNumElements(); 298 EVT OldVT = N->getOperand(0).getValueType(); 299 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT); 300 DebugLoc dl = N->getDebugLoc(); 301 302 assert(OldVT == VecVT.getVectorElementType() && 303 "BUILD_VECTOR operand type doesn't match vector element type!"); 304 305 // Build a vector of twice the length out of the expanded elements. 306 // For example <3 x i64> -> <6 x i32>. 307 std::vector<SDValue> NewElts; 308 NewElts.reserve(NumElts*2); 309 310 for (unsigned i = 0; i < NumElts; ++i) { 311 SDValue Lo, Hi; 312 GetExpandedOp(N->getOperand(i), Lo, Hi); 313 if (TLI.isBigEndian()) 314 std::swap(Lo, Hi); 315 NewElts.push_back(Lo); 316 NewElts.push_back(Hi); 317 } 318 319 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl, 320 EVT::getVectorVT(*DAG.getContext(), 321 NewVT, NewElts.size()), 322 &NewElts[0], NewElts.size()); 323 324 // Convert the new vector to the old vector type. 325 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 326} 327 328SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) { 329 SDValue Lo, Hi; 330 GetExpandedOp(N->getOperand(0), Lo, Hi); 331 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo; 332} 333 334SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) { 335 // The vector type is legal but the element type needs expansion. 336 EVT VecVT = N->getValueType(0); 337 unsigned NumElts = VecVT.getVectorNumElements(); 338 DebugLoc dl = N->getDebugLoc(); 339 340 SDValue Val = N->getOperand(1); 341 EVT OldEVT = Val.getValueType(); 342 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT); 343 344 assert(OldEVT == VecVT.getVectorElementType() && 345 "Inserted element type doesn't match vector element type!"); 346 347 // Bitconvert to a vector of twice the length with elements of the expanded 348 // type, insert the expanded vector elements, and then convert back. 349 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2); 350 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl, 351 NewVecVT, N->getOperand(0)); 352 353 SDValue Lo, Hi; 354 GetExpandedOp(Val, Lo, Hi); 355 if (TLI.isBigEndian()) 356 std::swap(Lo, Hi); 357 358 SDValue Idx = N->getOperand(2); 359 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 360 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx); 361 Idx = DAG.getNode(ISD::ADD, dl, 362 Idx.getValueType(), Idx, DAG.getIntPtrConstant(1)); 363 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx); 364 365 // Convert the new vector to the old vector type. 366 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 367} 368 369SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) { 370 DebugLoc dl = N->getDebugLoc(); 371 EVT VT = N->getValueType(0); 372 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() && 373 "SCALAR_TO_VECTOR operand type doesn't match vector element type!"); 374 unsigned NumElts = VT.getVectorNumElements(); 375 SmallVector<SDValue, 16> Ops(NumElts); 376 Ops[0] = N->getOperand(0); 377 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType()); 378 for (unsigned i = 1; i < NumElts; ++i) 379 Ops[i] = UndefVal; 380 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts); 381} 382 383SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) { 384 assert(ISD::isNormalStore(N) && "This routine only for normal stores!"); 385 assert(OpNo == 1 && "Can only expand the stored value so far"); 386 DebugLoc dl = N->getDebugLoc(); 387 388 StoreSDNode *St = cast<StoreSDNode>(N); 389 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), 390 St->getValue().getValueType()); 391 SDValue Chain = St->getChain(); 392 SDValue Ptr = St->getBasePtr(); 393 int SVOffset = St->getSrcValueOffset(); 394 unsigned Alignment = St->getAlignment(); 395 bool isVolatile = St->isVolatile(); 396 bool isNonTemporal = St->isNonTemporal(); 397 398 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 399 unsigned IncrementSize = NVT.getSizeInBits() / 8; 400 401 SDValue Lo, Hi; 402 GetExpandedOp(St->getValue(), Lo, Hi); 403 404 if (TLI.isBigEndian()) 405 std::swap(Lo, Hi); 406 407 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getSrcValue(), SVOffset, 408 isVolatile, isNonTemporal, Alignment); 409 410 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 411 DAG.getIntPtrConstant(IncrementSize)); 412 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!"); 413 Hi = DAG.getStore(Chain, dl, Hi, Ptr, St->getSrcValue(), 414 SVOffset + IncrementSize, 415 isVolatile, isNonTemporal, 416 MinAlign(Alignment, IncrementSize)); 417 418 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi); 419} 420 421 422//===--------------------------------------------------------------------===// 423// Generic Result Splitting. 424//===--------------------------------------------------------------------===// 425 426// Be careful to make no assumptions about which of Lo/Hi is stored first in 427// memory (for vectors it is always Lo first followed by Hi in the following 428// bytes; for integers and floats it is Lo first if and only if the machine is 429// little-endian). 430 431void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, 432 SDValue &Lo, SDValue &Hi) { 433 // A MERGE_VALUES node can produce any number of values. We know that the 434 // first illegal one needs to be expanded into Lo/Hi. 435 unsigned i; 436 437 // The string of legal results gets turned into input operands, which have 438 // the same type. 439 for (i = 0; isTypeLegal(N->getValueType(i)); ++i) 440 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 441 442 // The first illegal result must be the one that needs to be expanded. 443 GetSplitOp(N->getOperand(i), Lo, Hi); 444 445 // Legalize the rest of the results into the input operands whether they are 446 // legal or not. 447 unsigned e = N->getNumValues(); 448 for (++i; i != e; ++i) 449 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 450} 451 452void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo, 453 SDValue &Hi) { 454 SDValue LL, LH, RL, RH; 455 DebugLoc dl = N->getDebugLoc(); 456 GetSplitOp(N->getOperand(1), LL, LH); 457 GetSplitOp(N->getOperand(2), RL, RH); 458 459 SDValue Cond = N->getOperand(0); 460 Lo = DAG.getNode(ISD::SELECT, dl, LL.getValueType(), Cond, LL, RL); 461 Hi = DAG.getNode(ISD::SELECT, dl, LH.getValueType(), Cond, LH, RH); 462} 463 464void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo, 465 SDValue &Hi) { 466 SDValue LL, LH, RL, RH; 467 DebugLoc dl = N->getDebugLoc(); 468 GetSplitOp(N->getOperand(2), LL, LH); 469 GetSplitOp(N->getOperand(3), RL, RH); 470 471 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0), 472 N->getOperand(1), LL, RL, N->getOperand(4)); 473 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0), 474 N->getOperand(1), LH, RH, N->getOperand(4)); 475} 476 477void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) { 478 EVT LoVT, HiVT; 479 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT); 480 Lo = DAG.getUNDEF(LoVT); 481 Hi = DAG.getUNDEF(HiVT); 482} 483