LegalizeTypesGeneric.cpp revision 207618
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(), 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 int SVOffset = LD->getSrcValueOffset(); 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->getSrcValue(), SVOffset, 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, LD->getSrcValue(), 222 SVOffset+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 NVT = TLI.getTypeToTransformTo(*DAG.getContext(), N->getValueType(0)); 242 SDValue Chain = N->getOperand(0); 243 SDValue Ptr = N->getOperand(1); 244 DebugLoc dl = N->getDebugLoc(); 245 246 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2)); 247 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2)); 248 249 // Handle endianness of the load. 250 if (TLI.isBigEndian()) 251 std::swap(Lo, Hi); 252 253 // Modified the chain - switch anything that used the old chain to use 254 // the new one. 255 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1)); 256} 257 258 259//===--------------------------------------------------------------------===// 260// Generic Operand Expansion. 261//===--------------------------------------------------------------------===// 262 263SDValue DAGTypeLegalizer::ExpandOp_BIT_CONVERT(SDNode *N) { 264 DebugLoc dl = N->getDebugLoc(); 265 if (N->getValueType(0).isVector()) { 266 // An illegal expanding type is being converted to a legal vector type. 267 // Make a two element vector out of the expanded parts and convert that 268 // instead, but only if the new vector type is legal (otherwise there 269 // is no point, and it might create expansion loops). For example, on 270 // x86 this turns v1i64 = BIT_CONVERT i64 into v1i64 = BIT_CONVERT v2i32. 271 EVT OVT = N->getOperand(0).getValueType(); 272 EVT NVT = EVT::getVectorVT(*DAG.getContext(), 273 TLI.getTypeToTransformTo(*DAG.getContext(), OVT), 274 2); 275 276 if (isTypeLegal(NVT)) { 277 SDValue Parts[2]; 278 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]); 279 280 if (TLI.isBigEndian()) 281 std::swap(Parts[0], Parts[1]); 282 283 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2); 284 return DAG.getNode(ISD::BIT_CONVERT, dl, N->getValueType(0), Vec); 285 } 286 } 287 288 // Otherwise, store to a temporary and load out again as the new type. 289 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0)); 290} 291 292SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) { 293 // The vector type is legal but the element type needs expansion. 294 EVT VecVT = N->getValueType(0); 295 unsigned NumElts = VecVT.getVectorNumElements(); 296 EVT OldVT = N->getOperand(0).getValueType(); 297 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT); 298 DebugLoc dl = N->getDebugLoc(); 299 300 assert(OldVT == VecVT.getVectorElementType() && 301 "BUILD_VECTOR operand type doesn't match vector element type!"); 302 303 // Build a vector of twice the length out of the expanded elements. 304 // For example <3 x i64> -> <6 x i32>. 305 std::vector<SDValue> NewElts; 306 NewElts.reserve(NumElts*2); 307 308 for (unsigned i = 0; i < NumElts; ++i) { 309 SDValue Lo, Hi; 310 GetExpandedOp(N->getOperand(i), Lo, Hi); 311 if (TLI.isBigEndian()) 312 std::swap(Lo, Hi); 313 NewElts.push_back(Lo); 314 NewElts.push_back(Hi); 315 } 316 317 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl, 318 EVT::getVectorVT(*DAG.getContext(), 319 NewVT, NewElts.size()), 320 &NewElts[0], NewElts.size()); 321 322 // Convert the new vector to the old vector type. 323 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 324} 325 326SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) { 327 SDValue Lo, Hi; 328 GetExpandedOp(N->getOperand(0), Lo, Hi); 329 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo; 330} 331 332SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) { 333 // The vector type is legal but the element type needs expansion. 334 EVT VecVT = N->getValueType(0); 335 unsigned NumElts = VecVT.getVectorNumElements(); 336 DebugLoc dl = N->getDebugLoc(); 337 338 SDValue Val = N->getOperand(1); 339 EVT OldEVT = Val.getValueType(); 340 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT); 341 342 assert(OldEVT == VecVT.getVectorElementType() && 343 "Inserted element type doesn't match vector element type!"); 344 345 // Bitconvert to a vector of twice the length with elements of the expanded 346 // type, insert the expanded vector elements, and then convert back. 347 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2); 348 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl, 349 NewVecVT, N->getOperand(0)); 350 351 SDValue Lo, Hi; 352 GetExpandedOp(Val, Lo, Hi); 353 if (TLI.isBigEndian()) 354 std::swap(Lo, Hi); 355 356 SDValue Idx = N->getOperand(2); 357 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 358 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx); 359 Idx = DAG.getNode(ISD::ADD, dl, 360 Idx.getValueType(), Idx, DAG.getIntPtrConstant(1)); 361 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx); 362 363 // Convert the new vector to the old vector type. 364 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 365} 366 367SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) { 368 DebugLoc dl = N->getDebugLoc(); 369 EVT VT = N->getValueType(0); 370 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() && 371 "SCALAR_TO_VECTOR operand type doesn't match vector element type!"); 372 unsigned NumElts = VT.getVectorNumElements(); 373 SmallVector<SDValue, 16> Ops(NumElts); 374 Ops[0] = N->getOperand(0); 375 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType()); 376 for (unsigned i = 1; i < NumElts; ++i) 377 Ops[i] = UndefVal; 378 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts); 379} 380 381SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) { 382 assert(ISD::isNormalStore(N) && "This routine only for normal stores!"); 383 assert(OpNo == 1 && "Can only expand the stored value so far"); 384 DebugLoc dl = N->getDebugLoc(); 385 386 StoreSDNode *St = cast<StoreSDNode>(N); 387 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), 388 St->getValue().getValueType()); 389 SDValue Chain = St->getChain(); 390 SDValue Ptr = St->getBasePtr(); 391 int SVOffset = St->getSrcValueOffset(); 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->getSrcValue(), SVOffset, 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, St->getSrcValue(), 412 SVOffset + 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