LegalizeTypesGeneric.cpp revision 77e61b46fce5e165ecfedb5666c43b3d2c1dc971
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::getStackObject(SPFI); 123 124 // Emit a store to the stack slot. 125 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, SV, 0); 126 127 // Load the first half from the stack slot. 128 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, SV, 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, SV, IncrementSize, false, 137 MinAlign(Alignment, IncrementSize)); 138 139 // Handle endianness of the load. 140 if (TLI.isBigEndian()) 141 std::swap(Lo, Hi); 142} 143 144void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo, 145 SDValue &Hi) { 146 // Return the operands. 147 Lo = N->getOperand(0); 148 Hi = N->getOperand(1); 149} 150 151void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo, 152 SDValue &Hi) { 153 GetExpandedOp(N->getOperand(0), Lo, Hi); 154 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? 155 Hi : Lo; 156 157 assert(Part.getValueType() == N->getValueType(0) && 158 "Type twice as big as expanded type not itself expanded!"); 159 160 GetPairElements(Part, Lo, Hi); 161} 162 163void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo, 164 SDValue &Hi) { 165 SDValue OldVec = N->getOperand(0); 166 unsigned OldElts = OldVec.getValueType().getVectorNumElements(); 167 DebugLoc dl = N->getDebugLoc(); 168 169 // Convert to a vector of the expanded element type, for example 170 // <3 x i64> -> <6 x i32>. 171 EVT OldVT = N->getValueType(0); 172 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT); 173 174 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl, 175 EVT::getVectorVT(*DAG.getContext(), NewVT, 2*OldElts), 176 OldVec); 177 178 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector. 179 SDValue Idx = N->getOperand(1); 180 181 // Make sure the type of Idx is big enough to hold the new values. 182 if (Idx.getValueType().bitsLT(TLI.getPointerTy())) 183 Idx = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Idx); 184 185 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 186 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 187 188 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, 189 DAG.getConstant(1, Idx.getValueType())); 190 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 191 192 if (TLI.isBigEndian()) 193 std::swap(Lo, Hi); 194} 195 196void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo, 197 SDValue &Hi) { 198 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!"); 199 DebugLoc dl = N->getDebugLoc(); 200 201 LoadSDNode *LD = cast<LoadSDNode>(N); 202 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), LD->getValueType(0)); 203 SDValue Chain = LD->getChain(); 204 SDValue Ptr = LD->getBasePtr(); 205 int SVOffset = LD->getSrcValueOffset(); 206 unsigned Alignment = LD->getAlignment(); 207 bool isVolatile = LD->isVolatile(); 208 209 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 210 211 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getSrcValue(), SVOffset, 212 isVolatile, Alignment); 213 214 // Increment the pointer to the other half. 215 unsigned IncrementSize = NVT.getSizeInBits() / 8; 216 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 217 DAG.getIntPtrConstant(IncrementSize)); 218 Hi = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getSrcValue(), 219 SVOffset+IncrementSize, 220 isVolatile, MinAlign(Alignment, IncrementSize)); 221 222 // Build a factor node to remember that this load is independent of the 223 // other one. 224 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1), 225 Hi.getValue(1)); 226 227 // Handle endianness of the load. 228 if (TLI.isBigEndian()) 229 std::swap(Lo, Hi); 230 231 // Modified the chain - switch anything that used the old chain to use 232 // the new one. 233 ReplaceValueWith(SDValue(N, 1), Chain); 234} 235 236void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) { 237 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), N->getValueType(0)); 238 SDValue Chain = N->getOperand(0); 239 SDValue Ptr = N->getOperand(1); 240 DebugLoc dl = N->getDebugLoc(); 241 242 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2)); 243 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2)); 244 245 // Handle endianness of the load. 246 if (TLI.isBigEndian()) 247 std::swap(Lo, Hi); 248 249 // Modified the chain - switch anything that used the old chain to use 250 // the new one. 251 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1)); 252} 253 254 255//===--------------------------------------------------------------------===// 256// Generic Operand Expansion. 257//===--------------------------------------------------------------------===// 258 259SDValue DAGTypeLegalizer::ExpandOp_BIT_CONVERT(SDNode *N) { 260 DebugLoc dl = N->getDebugLoc(); 261 if (N->getValueType(0).isVector()) { 262 // An illegal expanding type is being converted to a legal vector type. 263 // Make a two element vector out of the expanded parts and convert that 264 // instead, but only if the new vector type is legal (otherwise there 265 // is no point, and it might create expansion loops). For example, on 266 // x86 this turns v1i64 = BIT_CONVERT i64 into v1i64 = BIT_CONVERT v2i32. 267 EVT OVT = N->getOperand(0).getValueType(); 268 EVT NVT = EVT::getVectorVT(*DAG.getContext(), TLI.getTypeToTransformTo(*DAG.getContext(), OVT), 2); 269 270 if (isTypeLegal(NVT)) { 271 SDValue Parts[2]; 272 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]); 273 274 if (TLI.isBigEndian()) 275 std::swap(Parts[0], Parts[1]); 276 277 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2); 278 return DAG.getNode(ISD::BIT_CONVERT, dl, N->getValueType(0), Vec); 279 } 280 } 281 282 // Otherwise, store to a temporary and load out again as the new type. 283 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0)); 284} 285 286SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) { 287 // The vector type is legal but the element type needs expansion. 288 EVT VecVT = N->getValueType(0); 289 unsigned NumElts = VecVT.getVectorNumElements(); 290 EVT OldVT = N->getOperand(0).getValueType(); 291 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT); 292 DebugLoc dl = N->getDebugLoc(); 293 294 assert(OldVT == VecVT.getVectorElementType() && 295 "BUILD_VECTOR operand type doesn't match vector element type!"); 296 297 // Build a vector of twice the length out of the expanded elements. 298 // For example <3 x i64> -> <6 x i32>. 299 std::vector<SDValue> NewElts; 300 NewElts.reserve(NumElts*2); 301 302 for (unsigned i = 0; i < NumElts; ++i) { 303 SDValue Lo, Hi; 304 GetExpandedOp(N->getOperand(i), Lo, Hi); 305 if (TLI.isBigEndian()) 306 std::swap(Lo, Hi); 307 NewElts.push_back(Lo); 308 NewElts.push_back(Hi); 309 } 310 311 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl, 312 EVT::getVectorVT(*DAG.getContext(), NewVT, NewElts.size()), 313 &NewElts[0], NewElts.size()); 314 315 // Convert the new vector to the old vector type. 316 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 317} 318 319SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) { 320 SDValue Lo, Hi; 321 GetExpandedOp(N->getOperand(0), Lo, Hi); 322 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo; 323} 324 325SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) { 326 // The vector type is legal but the element type needs expansion. 327 EVT VecVT = N->getValueType(0); 328 unsigned NumElts = VecVT.getVectorNumElements(); 329 DebugLoc dl = N->getDebugLoc(); 330 331 SDValue Val = N->getOperand(1); 332 EVT OldEVT = Val.getValueType(); 333 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT); 334 335 assert(OldEVT == VecVT.getVectorElementType() && 336 "Inserted element type doesn't match vector element type!"); 337 338 // Bitconvert to a vector of twice the length with elements of the expanded 339 // type, insert the expanded vector elements, and then convert back. 340 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2); 341 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl, 342 NewVecVT, N->getOperand(0)); 343 344 SDValue Lo, Hi; 345 GetExpandedOp(Val, Lo, Hi); 346 if (TLI.isBigEndian()) 347 std::swap(Lo, Hi); 348 349 SDValue Idx = N->getOperand(2); 350 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 351 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx); 352 Idx = DAG.getNode(ISD::ADD, dl, 353 Idx.getValueType(), Idx, DAG.getIntPtrConstant(1)); 354 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx); 355 356 // Convert the new vector to the old vector type. 357 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 358} 359 360SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) { 361 DebugLoc dl = N->getDebugLoc(); 362 EVT VT = N->getValueType(0); 363 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() && 364 "SCALAR_TO_VECTOR operand type doesn't match vector element type!"); 365 unsigned NumElts = VT.getVectorNumElements(); 366 SmallVector<SDValue, 16> Ops(NumElts); 367 Ops[0] = N->getOperand(0); 368 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType()); 369 for (unsigned i = 1; i < NumElts; ++i) 370 Ops[i] = UndefVal; 371 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts); 372} 373 374SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) { 375 assert(ISD::isNormalStore(N) && "This routine only for normal stores!"); 376 assert(OpNo == 1 && "Can only expand the stored value so far"); 377 DebugLoc dl = N->getDebugLoc(); 378 379 StoreSDNode *St = cast<StoreSDNode>(N); 380 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), St->getValue().getValueType()); 381 SDValue Chain = St->getChain(); 382 SDValue Ptr = St->getBasePtr(); 383 int SVOffset = St->getSrcValueOffset(); 384 unsigned Alignment = St->getAlignment(); 385 bool isVolatile = St->isVolatile(); 386 387 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 388 unsigned IncrementSize = NVT.getSizeInBits() / 8; 389 390 SDValue Lo, Hi; 391 GetExpandedOp(St->getValue(), Lo, Hi); 392 393 if (TLI.isBigEndian()) 394 std::swap(Lo, Hi); 395 396 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getSrcValue(), SVOffset, 397 isVolatile, Alignment); 398 399 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 400 DAG.getIntPtrConstant(IncrementSize)); 401 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!"); 402 Hi = DAG.getStore(Chain, dl, Hi, Ptr, St->getSrcValue(), 403 SVOffset + IncrementSize, 404 isVolatile, MinAlign(Alignment, IncrementSize)); 405 406 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi); 407} 408 409 410//===--------------------------------------------------------------------===// 411// Generic Result Splitting. 412//===--------------------------------------------------------------------===// 413 414// Be careful to make no assumptions about which of Lo/Hi is stored first in 415// memory (for vectors it is always Lo first followed by Hi in the following 416// bytes; for integers and floats it is Lo first if and only if the machine is 417// little-endian). 418 419void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, 420 SDValue &Lo, SDValue &Hi) { 421 // A MERGE_VALUES node can produce any number of values. We know that the 422 // first illegal one needs to be expanded into Lo/Hi. 423 unsigned i; 424 425 // The string of legal results gets turned into input operands, which have 426 // the same type. 427 for (i = 0; isTypeLegal(N->getValueType(i)); ++i) 428 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 429 430 // The first illegal result must be the one that needs to be expanded. 431 GetSplitOp(N->getOperand(i), Lo, Hi); 432 433 // Legalize the rest of the results into the input operands whether they are 434 // legal or not. 435 unsigned e = N->getNumValues(); 436 for (++i; i != e; ++i) 437 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 438} 439 440void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo, 441 SDValue &Hi) { 442 SDValue LL, LH, RL, RH; 443 DebugLoc dl = N->getDebugLoc(); 444 GetSplitOp(N->getOperand(1), LL, LH); 445 GetSplitOp(N->getOperand(2), RL, RH); 446 447 SDValue Cond = N->getOperand(0); 448 Lo = DAG.getNode(ISD::SELECT, dl, LL.getValueType(), Cond, LL, RL); 449 Hi = DAG.getNode(ISD::SELECT, dl, LH.getValueType(), Cond, LH, RH); 450} 451 452void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo, 453 SDValue &Hi) { 454 SDValue LL, LH, RL, RH; 455 DebugLoc dl = N->getDebugLoc(); 456 GetSplitOp(N->getOperand(2), LL, LH); 457 GetSplitOp(N->getOperand(3), RL, RH); 458 459 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0), 460 N->getOperand(1), LL, RL, N->getOperand(4)); 461 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0), 462 N->getOperand(1), LH, RH, N->getOperand(4)); 463} 464 465void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) { 466 EVT LoVT, HiVT; 467 DebugLoc dl = N->getDebugLoc(); 468 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT); 469 Lo = DAG.getUNDEF(LoVT); 470 Hi = DAG.getUNDEF(HiVT); 471} 472