LegalizeTypesGeneric.cpp revision 1e559443a17d1b335f697551c6263ba60d5dd827
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 const Value *SV = PseudoSourceValue::getFixedStack(SPFI); 123 124 // Emit a store to the stack slot. 125 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, SV, 0, 126 false, false, 0); 127 128 // Load the first half from the stack slot. 129 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, SV, 0, 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, SV, 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::BIT_CONVERT, dl, 176 EVT::getVectorVT(*DAG.getContext(), NewVT, 2*OldElts), 177 OldVec); 178 179 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector. 180 SDValue Idx = N->getOperand(1); 181 182 // Make sure the type of Idx is big enough to hold the new values. 183 if (Idx.getValueType().bitsLT(TLI.getPointerTy())) 184 Idx = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Idx); 185 186 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 187 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 188 189 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, 190 DAG.getConstant(1, Idx.getValueType())); 191 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 192 193 if (TLI.isBigEndian()) 194 std::swap(Lo, Hi); 195} 196 197void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo, 198 SDValue &Hi) { 199 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!"); 200 DebugLoc dl = N->getDebugLoc(); 201 202 LoadSDNode *LD = cast<LoadSDNode>(N); 203 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), LD->getValueType(0)); 204 SDValue Chain = LD->getChain(); 205 SDValue Ptr = LD->getBasePtr(); 206 int SVOffset = LD->getSrcValueOffset(); 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->getSrcValue(), SVOffset, 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, LD->getSrcValue(), 221 SVOffset+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 NVT = TLI.getTypeToTransformTo(*DAG.getContext(), N->getValueType(0)); 241 SDValue Chain = N->getOperand(0); 242 SDValue Ptr = N->getOperand(1); 243 DebugLoc dl = N->getDebugLoc(); 244 245 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2)); 246 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2)); 247 248 // Handle endianness of the load. 249 if (TLI.isBigEndian()) 250 std::swap(Lo, Hi); 251 252 // Modified the chain - switch anything that used the old chain to use 253 // the new one. 254 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1)); 255} 256 257 258//===--------------------------------------------------------------------===// 259// Generic Operand Expansion. 260//===--------------------------------------------------------------------===// 261 262SDValue DAGTypeLegalizer::ExpandOp_BIT_CONVERT(SDNode *N) { 263 DebugLoc dl = N->getDebugLoc(); 264 if (N->getValueType(0).isVector()) { 265 // An illegal expanding type is being converted to a legal vector type. 266 // Make a two element vector out of the expanded parts and convert that 267 // instead, but only if the new vector type is legal (otherwise there 268 // is no point, and it might create expansion loops). For example, on 269 // x86 this turns v1i64 = BIT_CONVERT i64 into v1i64 = BIT_CONVERT v2i32. 270 EVT OVT = N->getOperand(0).getValueType(); 271 EVT NVT = EVT::getVectorVT(*DAG.getContext(), TLI.getTypeToTransformTo(*DAG.getContext(), OVT), 2); 272 273 if (isTypeLegal(NVT)) { 274 SDValue Parts[2]; 275 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]); 276 277 if (TLI.isBigEndian()) 278 std::swap(Parts[0], Parts[1]); 279 280 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2); 281 return DAG.getNode(ISD::BIT_CONVERT, dl, N->getValueType(0), Vec); 282 } 283 } 284 285 // Otherwise, store to a temporary and load out again as the new type. 286 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0)); 287} 288 289SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) { 290 // The vector type is legal but the element type needs expansion. 291 EVT VecVT = N->getValueType(0); 292 unsigned NumElts = VecVT.getVectorNumElements(); 293 EVT OldVT = N->getOperand(0).getValueType(); 294 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT); 295 DebugLoc dl = N->getDebugLoc(); 296 297 assert(OldVT == VecVT.getVectorElementType() && 298 "BUILD_VECTOR operand type doesn't match vector element type!"); 299 300 // Build a vector of twice the length out of the expanded elements. 301 // For example <3 x i64> -> <6 x i32>. 302 std::vector<SDValue> NewElts; 303 NewElts.reserve(NumElts*2); 304 305 for (unsigned i = 0; i < NumElts; ++i) { 306 SDValue Lo, Hi; 307 GetExpandedOp(N->getOperand(i), Lo, Hi); 308 if (TLI.isBigEndian()) 309 std::swap(Lo, Hi); 310 NewElts.push_back(Lo); 311 NewElts.push_back(Hi); 312 } 313 314 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl, 315 EVT::getVectorVT(*DAG.getContext(), NewVT, NewElts.size()), 316 &NewElts[0], NewElts.size()); 317 318 // Convert the new vector to the old vector type. 319 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 320} 321 322SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) { 323 SDValue Lo, Hi; 324 GetExpandedOp(N->getOperand(0), Lo, Hi); 325 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo; 326} 327 328SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) { 329 // The vector type is legal but the element type needs expansion. 330 EVT VecVT = N->getValueType(0); 331 unsigned NumElts = VecVT.getVectorNumElements(); 332 DebugLoc dl = N->getDebugLoc(); 333 334 SDValue Val = N->getOperand(1); 335 EVT OldEVT = Val.getValueType(); 336 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT); 337 338 assert(OldEVT == VecVT.getVectorElementType() && 339 "Inserted element type doesn't match vector element type!"); 340 341 // Bitconvert to a vector of twice the length with elements of the expanded 342 // type, insert the expanded vector elements, and then convert back. 343 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2); 344 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl, 345 NewVecVT, N->getOperand(0)); 346 347 SDValue Lo, Hi; 348 GetExpandedOp(Val, Lo, Hi); 349 if (TLI.isBigEndian()) 350 std::swap(Lo, Hi); 351 352 SDValue Idx = N->getOperand(2); 353 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 354 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx); 355 Idx = DAG.getNode(ISD::ADD, dl, 356 Idx.getValueType(), Idx, DAG.getIntPtrConstant(1)); 357 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx); 358 359 // Convert the new vector to the old vector type. 360 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 361} 362 363SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) { 364 DebugLoc dl = N->getDebugLoc(); 365 EVT VT = N->getValueType(0); 366 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() && 367 "SCALAR_TO_VECTOR operand type doesn't match vector element type!"); 368 unsigned NumElts = VT.getVectorNumElements(); 369 SmallVector<SDValue, 16> Ops(NumElts); 370 Ops[0] = N->getOperand(0); 371 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType()); 372 for (unsigned i = 1; i < NumElts; ++i) 373 Ops[i] = UndefVal; 374 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts); 375} 376 377SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) { 378 assert(ISD::isNormalStore(N) && "This routine only for normal stores!"); 379 assert(OpNo == 1 && "Can only expand the stored value so far"); 380 DebugLoc dl = N->getDebugLoc(); 381 382 StoreSDNode *St = cast<StoreSDNode>(N); 383 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), St->getValue().getValueType()); 384 SDValue Chain = St->getChain(); 385 SDValue Ptr = St->getBasePtr(); 386 int SVOffset = St->getSrcValueOffset(); 387 unsigned Alignment = St->getAlignment(); 388 bool isVolatile = St->isVolatile(); 389 bool isNonTemporal = St->isNonTemporal(); 390 391 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 392 unsigned IncrementSize = NVT.getSizeInBits() / 8; 393 394 SDValue Lo, Hi; 395 GetExpandedOp(St->getValue(), Lo, Hi); 396 397 if (TLI.isBigEndian()) 398 std::swap(Lo, Hi); 399 400 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getSrcValue(), SVOffset, 401 isVolatile, isNonTemporal, Alignment); 402 403 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 404 DAG.getIntPtrConstant(IncrementSize)); 405 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!"); 406 Hi = DAG.getStore(Chain, dl, Hi, Ptr, St->getSrcValue(), 407 SVOffset + IncrementSize, 408 isVolatile, isNonTemporal, 409 MinAlign(Alignment, IncrementSize)); 410 411 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi); 412} 413 414 415//===--------------------------------------------------------------------===// 416// Generic Result Splitting. 417//===--------------------------------------------------------------------===// 418 419// Be careful to make no assumptions about which of Lo/Hi is stored first in 420// memory (for vectors it is always Lo first followed by Hi in the following 421// bytes; for integers and floats it is Lo first if and only if the machine is 422// little-endian). 423 424void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, 425 SDValue &Lo, SDValue &Hi) { 426 // A MERGE_VALUES node can produce any number of values. We know that the 427 // first illegal one needs to be expanded into Lo/Hi. 428 unsigned i; 429 430 // The string of legal results gets turned into input operands, which have 431 // the same type. 432 for (i = 0; isTypeLegal(N->getValueType(i)); ++i) 433 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 434 435 // The first illegal result must be the one that needs to be expanded. 436 GetSplitOp(N->getOperand(i), Lo, Hi); 437 438 // Legalize the rest of the results into the input operands whether they are 439 // legal or not. 440 unsigned e = N->getNumValues(); 441 for (++i; i != e; ++i) 442 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 443} 444 445void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo, 446 SDValue &Hi) { 447 SDValue LL, LH, RL, RH; 448 DebugLoc dl = N->getDebugLoc(); 449 GetSplitOp(N->getOperand(1), LL, LH); 450 GetSplitOp(N->getOperand(2), RL, RH); 451 452 SDValue Cond = N->getOperand(0); 453 Lo = DAG.getNode(ISD::SELECT, dl, LL.getValueType(), Cond, LL, RL); 454 Hi = DAG.getNode(ISD::SELECT, dl, LH.getValueType(), Cond, LH, RH); 455} 456 457void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo, 458 SDValue &Hi) { 459 SDValue LL, LH, RL, RH; 460 DebugLoc dl = N->getDebugLoc(); 461 GetSplitOp(N->getOperand(2), LL, LH); 462 GetSplitOp(N->getOperand(3), RL, RH); 463 464 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0), 465 N->getOperand(1), LL, RL, N->getOperand(4)); 466 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0), 467 N->getOperand(1), LH, RH, N->getOperand(4)); 468} 469 470void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) { 471 EVT LoVT, HiVT; 472 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT); 473 Lo = DAG.getUNDEF(LoVT); 474 Hi = DAG.getUNDEF(HiVT); 475} 476