LegalizeTypesGeneric.cpp revision 825b72b0571821bf2d378749f69d6c4cfb52d2f9
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(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(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(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.getTypeForEVT()); 119 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment); 120 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex(); 121 const Value *SV = PseudoSourceValue::getFixedStack(SPFI); 122 123 // Emit a store to the stack slot. 124 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, SV, 0); 125 126 // Load the first half from the stack slot. 127 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, SV, 0); 128 129 // Increment the pointer to the other half. 130 unsigned IncrementSize = NOutVT.getSizeInBits() / 8; 131 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr, 132 DAG.getIntPtrConstant(IncrementSize)); 133 134 // Load the second half from the stack slot. 135 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr, SV, IncrementSize, false, 136 MinAlign(Alignment, IncrementSize)); 137 138 // Handle endianness of the load. 139 if (TLI.isBigEndian()) 140 std::swap(Lo, Hi); 141} 142 143void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo, 144 SDValue &Hi) { 145 // Return the operands. 146 Lo = N->getOperand(0); 147 Hi = N->getOperand(1); 148} 149 150void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo, 151 SDValue &Hi) { 152 GetExpandedOp(N->getOperand(0), Lo, Hi); 153 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? 154 Hi : Lo; 155 156 assert(Part.getValueType() == N->getValueType(0) && 157 "Type twice as big as expanded type not itself expanded!"); 158 159 GetPairElements(Part, Lo, Hi); 160} 161 162void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo, 163 SDValue &Hi) { 164 SDValue OldVec = N->getOperand(0); 165 unsigned OldElts = OldVec.getValueType().getVectorNumElements(); 166 DebugLoc dl = N->getDebugLoc(); 167 168 // Convert to a vector of the expanded element type, for example 169 // <3 x i64> -> <6 x i32>. 170 EVT OldVT = N->getValueType(0); 171 EVT NewVT = TLI.getTypeToTransformTo(OldVT); 172 173 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl, 174 EVT::getVectorVT(NewVT, 2*OldElts), 175 OldVec); 176 177 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector. 178 SDValue Idx = N->getOperand(1); 179 180 // Make sure the type of Idx is big enough to hold the new values. 181 if (Idx.getValueType().bitsLT(TLI.getPointerTy())) 182 Idx = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Idx); 183 184 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 185 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 186 187 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, 188 DAG.getConstant(1, Idx.getValueType())); 189 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 190 191 if (TLI.isBigEndian()) 192 std::swap(Lo, Hi); 193} 194 195void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo, 196 SDValue &Hi) { 197 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!"); 198 DebugLoc dl = N->getDebugLoc(); 199 200 LoadSDNode *LD = cast<LoadSDNode>(N); 201 EVT NVT = TLI.getTypeToTransformTo(LD->getValueType(0)); 202 SDValue Chain = LD->getChain(); 203 SDValue Ptr = LD->getBasePtr(); 204 int SVOffset = LD->getSrcValueOffset(); 205 unsigned Alignment = LD->getAlignment(); 206 bool isVolatile = LD->isVolatile(); 207 208 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 209 210 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getSrcValue(), SVOffset, 211 isVolatile, Alignment); 212 213 // Increment the pointer to the other half. 214 unsigned IncrementSize = NVT.getSizeInBits() / 8; 215 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 216 DAG.getIntPtrConstant(IncrementSize)); 217 Hi = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getSrcValue(), 218 SVOffset+IncrementSize, 219 isVolatile, MinAlign(Alignment, IncrementSize)); 220 221 // Build a factor node to remember that this load is independent of the 222 // other one. 223 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1), 224 Hi.getValue(1)); 225 226 // Handle endianness of the load. 227 if (TLI.isBigEndian()) 228 std::swap(Lo, Hi); 229 230 // Modified the chain - switch anything that used the old chain to use 231 // the new one. 232 ReplaceValueWith(SDValue(N, 1), Chain); 233} 234 235void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) { 236 EVT NVT = TLI.getTypeToTransformTo(N->getValueType(0)); 237 SDValue Chain = N->getOperand(0); 238 SDValue Ptr = N->getOperand(1); 239 DebugLoc dl = N->getDebugLoc(); 240 241 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2)); 242 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2)); 243 244 // Handle endianness of the load. 245 if (TLI.isBigEndian()) 246 std::swap(Lo, Hi); 247 248 // Modified the chain - switch anything that used the old chain to use 249 // the new one. 250 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1)); 251} 252 253 254//===--------------------------------------------------------------------===// 255// Generic Operand Expansion. 256//===--------------------------------------------------------------------===// 257 258SDValue DAGTypeLegalizer::ExpandOp_BIT_CONVERT(SDNode *N) { 259 DebugLoc dl = N->getDebugLoc(); 260 if (N->getValueType(0).isVector()) { 261 // An illegal expanding type is being converted to a legal vector type. 262 // Make a two element vector out of the expanded parts and convert that 263 // instead, but only if the new vector type is legal (otherwise there 264 // is no point, and it might create expansion loops). For example, on 265 // x86 this turns v1i64 = BIT_CONVERT i64 into v1i64 = BIT_CONVERT v2i32. 266 EVT OVT = N->getOperand(0).getValueType(); 267 EVT NVT = EVT::getVectorVT(TLI.getTypeToTransformTo(OVT), 2); 268 269 if (isTypeLegal(NVT)) { 270 SDValue Parts[2]; 271 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]); 272 273 if (TLI.isBigEndian()) 274 std::swap(Parts[0], Parts[1]); 275 276 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2); 277 return DAG.getNode(ISD::BIT_CONVERT, dl, N->getValueType(0), Vec); 278 } 279 } 280 281 // Otherwise, store to a temporary and load out again as the new type. 282 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0)); 283} 284 285SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) { 286 // The vector type is legal but the element type needs expansion. 287 EVT VecVT = N->getValueType(0); 288 unsigned NumElts = VecVT.getVectorNumElements(); 289 EVT OldVT = N->getOperand(0).getValueType(); 290 EVT NewVT = TLI.getTypeToTransformTo(OldVT); 291 DebugLoc dl = N->getDebugLoc(); 292 293 assert(OldVT == VecVT.getVectorElementType() && 294 "BUILD_VECTOR operand type doesn't match vector element type!"); 295 296 // Build a vector of twice the length out of the expanded elements. 297 // For example <3 x i64> -> <6 x i32>. 298 std::vector<SDValue> NewElts; 299 NewElts.reserve(NumElts*2); 300 301 for (unsigned i = 0; i < NumElts; ++i) { 302 SDValue Lo, Hi; 303 GetExpandedOp(N->getOperand(i), Lo, Hi); 304 if (TLI.isBigEndian()) 305 std::swap(Lo, Hi); 306 NewElts.push_back(Lo); 307 NewElts.push_back(Hi); 308 } 309 310 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl, 311 EVT::getVectorVT(NewVT, NewElts.size()), 312 &NewElts[0], NewElts.size()); 313 314 // Convert the new vector to the old vector type. 315 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 316} 317 318SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) { 319 SDValue Lo, Hi; 320 GetExpandedOp(N->getOperand(0), Lo, Hi); 321 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo; 322} 323 324SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) { 325 // The vector type is legal but the element type needs expansion. 326 EVT VecVT = N->getValueType(0); 327 unsigned NumElts = VecVT.getVectorNumElements(); 328 DebugLoc dl = N->getDebugLoc(); 329 330 SDValue Val = N->getOperand(1); 331 EVT OldEVT = Val.getValueType(); 332 EVT NewEVT = TLI.getTypeToTransformTo(OldEVT); 333 334 assert(OldEVT == VecVT.getVectorElementType() && 335 "Inserted element type doesn't match vector element type!"); 336 337 // Bitconvert to a vector of twice the length with elements of the expanded 338 // type, insert the expanded vector elements, and then convert back. 339 EVT NewVecVT = EVT::getVectorVT(NewEVT, NumElts*2); 340 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl, 341 NewVecVT, N->getOperand(0)); 342 343 SDValue Lo, Hi; 344 GetExpandedOp(Val, Lo, Hi); 345 if (TLI.isBigEndian()) 346 std::swap(Lo, Hi); 347 348 SDValue Idx = N->getOperand(2); 349 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 350 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx); 351 Idx = DAG.getNode(ISD::ADD, dl, 352 Idx.getValueType(), Idx, DAG.getIntPtrConstant(1)); 353 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx); 354 355 // Convert the new vector to the old vector type. 356 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 357} 358 359SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) { 360 DebugLoc dl = N->getDebugLoc(); 361 EVT VT = N->getValueType(0); 362 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() && 363 "SCALAR_TO_VECTOR operand type doesn't match vector element type!"); 364 unsigned NumElts = VT.getVectorNumElements(); 365 SmallVector<SDValue, 16> Ops(NumElts); 366 Ops[0] = N->getOperand(0); 367 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType()); 368 for (unsigned i = 1; i < NumElts; ++i) 369 Ops[i] = UndefVal; 370 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts); 371} 372 373SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) { 374 assert(ISD::isNormalStore(N) && "This routine only for normal stores!"); 375 assert(OpNo == 1 && "Can only expand the stored value so far"); 376 DebugLoc dl = N->getDebugLoc(); 377 378 StoreSDNode *St = cast<StoreSDNode>(N); 379 EVT NVT = TLI.getTypeToTransformTo(St->getValue().getValueType()); 380 SDValue Chain = St->getChain(); 381 SDValue Ptr = St->getBasePtr(); 382 int SVOffset = St->getSrcValueOffset(); 383 unsigned Alignment = St->getAlignment(); 384 bool isVolatile = St->isVolatile(); 385 386 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 387 unsigned IncrementSize = NVT.getSizeInBits() / 8; 388 389 SDValue Lo, Hi; 390 GetExpandedOp(St->getValue(), Lo, Hi); 391 392 if (TLI.isBigEndian()) 393 std::swap(Lo, Hi); 394 395 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getSrcValue(), SVOffset, 396 isVolatile, Alignment); 397 398 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 399 DAG.getIntPtrConstant(IncrementSize)); 400 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!"); 401 Hi = DAG.getStore(Chain, dl, Hi, Ptr, St->getSrcValue(), 402 SVOffset + IncrementSize, 403 isVolatile, MinAlign(Alignment, IncrementSize)); 404 405 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi); 406} 407 408 409//===--------------------------------------------------------------------===// 410// Generic Result Splitting. 411//===--------------------------------------------------------------------===// 412 413// Be careful to make no assumptions about which of Lo/Hi is stored first in 414// memory (for vectors it is always Lo first followed by Hi in the following 415// bytes; for integers and floats it is Lo first if and only if the machine is 416// little-endian). 417 418void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, 419 SDValue &Lo, SDValue &Hi) { 420 // A MERGE_VALUES node can produce any number of values. We know that the 421 // first illegal one needs to be expanded into Lo/Hi. 422 unsigned i; 423 424 // The string of legal results gets turned into input operands, which have 425 // the same type. 426 for (i = 0; isTypeLegal(N->getValueType(i)); ++i) 427 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 428 429 // The first illegal result must be the one that needs to be expanded. 430 GetSplitOp(N->getOperand(i), Lo, Hi); 431 432 // Legalize the rest of the results into the input operands whether they are 433 // legal or not. 434 unsigned e = N->getNumValues(); 435 for (++i; i != e; ++i) 436 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 437} 438 439void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo, 440 SDValue &Hi) { 441 SDValue LL, LH, RL, RH; 442 DebugLoc dl = N->getDebugLoc(); 443 GetSplitOp(N->getOperand(1), LL, LH); 444 GetSplitOp(N->getOperand(2), RL, RH); 445 446 SDValue Cond = N->getOperand(0); 447 Lo = DAG.getNode(ISD::SELECT, dl, LL.getValueType(), Cond, LL, RL); 448 Hi = DAG.getNode(ISD::SELECT, dl, LH.getValueType(), Cond, LH, RH); 449} 450 451void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo, 452 SDValue &Hi) { 453 SDValue LL, LH, RL, RH; 454 DebugLoc dl = N->getDebugLoc(); 455 GetSplitOp(N->getOperand(2), LL, LH); 456 GetSplitOp(N->getOperand(3), RL, RH); 457 458 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0), 459 N->getOperand(1), LL, RL, N->getOperand(4)); 460 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0), 461 N->getOperand(1), LH, RH, N->getOperand(4)); 462} 463 464void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) { 465 EVT LoVT, HiVT; 466 DebugLoc dl = N->getDebugLoc(); 467 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT); 468 Lo = DAG.getUNDEF(LoVT); 469 Hi = DAG.getUNDEF(HiVT); 470} 471