LegalizeTypesGeneric.cpp revision aa9df0b0c3cef33514095bde2eedead986677955
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. 15// Splitting is the act of changing a computation in an illegal type to be a 16// computation in two not necessarily identical registers of a smaller type. 17// 18//===----------------------------------------------------------------------===// 19 20#include "LegalizeTypes.h" 21#include "llvm/Target/TargetData.h" 22#include "llvm/CodeGen/PseudoSourceValue.h" 23using namespace llvm; 24 25//===----------------------------------------------------------------------===// 26// Generic Result Expansion. 27//===----------------------------------------------------------------------===// 28 29// These routines assume that the Lo/Hi part is stored first in memory on 30// little/big-endian machines, followed by the Hi/Lo part. This means that 31// they cannot be used as is on vectors, for which Lo is always stored first. 32 33void DAGTypeLegalizer::ExpandRes_BIT_CONVERT(SDNode *N, SDValue &Lo, 34 SDValue &Hi) { 35 MVT OutVT = N->getValueType(0); 36 MVT NOutVT = TLI.getTypeToTransformTo(OutVT); 37 SDValue InOp = N->getOperand(0); 38 MVT InVT = InOp.getValueType(); 39 DebugLoc dl = N->getDebugLoc(); 40 41 // Handle some special cases efficiently. 42 switch (getTypeAction(InVT)) { 43 default: 44 assert(false && "Unknown type action!"); 45 case Legal: 46 case PromoteInteger: 47 break; 48 case SoftenFloat: 49 // Convert the integer operand instead. 50 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi); 51 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo); 52 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi); 53 return; 54 case ExpandInteger: 55 case ExpandFloat: 56 // Convert the expanded pieces of the input. 57 GetExpandedOp(InOp, Lo, Hi); 58 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo); 59 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi); 60 return; 61 case SplitVector: 62 // Convert the split parts of the input if it was split in two. 63 GetSplitVector(InOp, Lo, Hi); 64 if (Lo.getValueType() == Hi.getValueType()) { 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 } 71 break; 72 case ScalarizeVector: 73 // Convert the element instead. 74 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi); 75 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo); 76 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi); 77 return; 78 case WidenVector: { 79 assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BIT_CONVERT"); 80 InOp = GetWidenedVector(InOp); 81 MVT InNVT = MVT::getVectorVT(InVT.getVectorElementType(), 82 InVT.getVectorNumElements()/2); 83 Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, InNVT, InOp, 84 DAG.getIntPtrConstant(0)); 85 Hi = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, InNVT, InOp, 86 DAG.getIntPtrConstant(InNVT.getVectorNumElements())); 87 if (TLI.isBigEndian()) 88 std::swap(Lo, Hi); 89 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo); 90 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi); 91 return; 92 } 93 } 94 95 // Lower the bit-convert to a store/load from the stack. 96 assert(NOutVT.isByteSized() && "Expanded type not byte sized!"); 97 98 // Create the stack frame object. Make sure it is aligned for both 99 // the source and expanded destination types. 100 unsigned Alignment = 101 TLI.getTargetData()->getPrefTypeAlignment(NOutVT.getTypeForMVT()); 102 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment); 103 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex(); 104 const Value *SV = PseudoSourceValue::getFixedStack(SPFI); 105 106 // Emit a store to the stack slot. 107 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, SV, 0); 108 109 // Load the first half from the stack slot. 110 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, SV, 0); 111 112 // Increment the pointer to the other half. 113 unsigned IncrementSize = NOutVT.getSizeInBits() / 8; 114 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr, 115 DAG.getIntPtrConstant(IncrementSize)); 116 117 // Load the second half from the stack slot. 118 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr, SV, IncrementSize, false, 119 MinAlign(Alignment, IncrementSize)); 120 121 // Handle endianness of the load. 122 if (TLI.isBigEndian()) 123 std::swap(Lo, Hi); 124} 125 126void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo, 127 SDValue &Hi) { 128 // Return the operands. 129 Lo = N->getOperand(0); 130 Hi = N->getOperand(1); 131} 132 133void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo, 134 SDValue &Hi) { 135 GetExpandedOp(N->getOperand(0), Lo, Hi); 136 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? 137 Hi : Lo; 138 DebugLoc dl = N->getDebugLoc(); 139 140 assert(Part.getValueType() == N->getValueType(0) && 141 "Type twice as big as expanded type not itself expanded!"); 142 MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0)); 143 144 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Part, 145 DAG.getConstant(0, TLI.getPointerTy())); 146 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Part, 147 DAG.getConstant(1, TLI.getPointerTy())); 148} 149 150void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo, 151 SDValue &Hi) { 152 SDValue OldVec = N->getOperand(0); 153 unsigned OldElts = OldVec.getValueType().getVectorNumElements(); 154 DebugLoc dl = N->getDebugLoc(); 155 156 // Convert to a vector of the expanded element type, for example 157 // <3 x i64> -> <6 x i32>. 158 MVT OldVT = N->getValueType(0); 159 MVT NewVT = TLI.getTypeToTransformTo(OldVT); 160 161 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl, 162 MVT::getVectorVT(NewVT, 2*OldElts), 163 OldVec); 164 165 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector. 166 SDValue Idx = N->getOperand(1); 167 168 // Make sure the type of Idx is big enough to hold the new values. 169 if (Idx.getValueType().bitsLT(TLI.getPointerTy())) 170 Idx = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Idx); 171 172 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 173 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 174 175 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, 176 DAG.getConstant(1, Idx.getValueType())); 177 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx); 178 179 if (TLI.isBigEndian()) 180 std::swap(Lo, Hi); 181} 182 183void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo, 184 SDValue &Hi) { 185 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!"); 186 DebugLoc dl = N->getDebugLoc(); 187 188 LoadSDNode *LD = cast<LoadSDNode>(N); 189 MVT NVT = TLI.getTypeToTransformTo(LD->getValueType(0)); 190 SDValue Chain = LD->getChain(); 191 SDValue Ptr = LD->getBasePtr(); 192 int SVOffset = LD->getSrcValueOffset(); 193 unsigned Alignment = LD->getAlignment(); 194 bool isVolatile = LD->isVolatile(); 195 196 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 197 198 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getSrcValue(), SVOffset, 199 isVolatile, Alignment); 200 201 // Increment the pointer to the other half. 202 unsigned IncrementSize = NVT.getSizeInBits() / 8; 203 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 204 DAG.getIntPtrConstant(IncrementSize)); 205 Hi = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getSrcValue(), 206 SVOffset+IncrementSize, 207 isVolatile, MinAlign(Alignment, IncrementSize)); 208 209 // Build a factor node to remember that this load is independent of the 210 // other one. 211 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1), 212 Hi.getValue(1)); 213 214 // Handle endianness of the load. 215 if (TLI.isBigEndian()) 216 std::swap(Lo, Hi); 217 218 // Modified the chain - switch anything that used the old chain to use 219 // the new one. 220 ReplaceValueWith(SDValue(N, 1), Chain); 221} 222 223void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) { 224 MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0)); 225 SDValue Chain = N->getOperand(0); 226 SDValue Ptr = N->getOperand(1); 227 DebugLoc dl = N->getDebugLoc(); 228 229 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2)); 230 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2)); 231 232 // Handle endianness of the load. 233 if (TLI.isBigEndian()) 234 std::swap(Lo, Hi); 235 236 // Modified the chain - switch anything that used the old chain to use 237 // the new one. 238 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1)); 239} 240 241 242//===--------------------------------------------------------------------===// 243// Generic Operand Expansion. 244//===--------------------------------------------------------------------===// 245 246SDValue DAGTypeLegalizer::ExpandOp_BIT_CONVERT(SDNode *N) { 247 DebugLoc dl = N->getDebugLoc(); 248 if (N->getValueType(0).isVector()) { 249 // An illegal expanding type is being converted to a legal vector type. 250 // Make a two element vector out of the expanded parts and convert that 251 // instead, but only if the new vector type is legal (otherwise there 252 // is no point, and it might create expansion loops). For example, on 253 // x86 this turns v1i64 = BIT_CONVERT i64 into v1i64 = BIT_CONVERT v2i32. 254 MVT OVT = N->getOperand(0).getValueType(); 255 MVT NVT = MVT::getVectorVT(TLI.getTypeToTransformTo(OVT), 2); 256 257 if (isTypeLegal(NVT)) { 258 SDValue Parts[2]; 259 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]); 260 261 if (TLI.isBigEndian()) 262 std::swap(Parts[0], Parts[1]); 263 264 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2); 265 return DAG.getNode(ISD::BIT_CONVERT, dl, N->getValueType(0), Vec); 266 } 267 } 268 269 // Otherwise, store to a temporary and load out again as the new type. 270 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0)); 271} 272 273SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) { 274 // The vector type is legal but the element type needs expansion. 275 MVT VecVT = N->getValueType(0); 276 unsigned NumElts = VecVT.getVectorNumElements(); 277 MVT OldVT = N->getOperand(0).getValueType(); 278 MVT NewVT = TLI.getTypeToTransformTo(OldVT); 279 DebugLoc dl = N->getDebugLoc(); 280 281 // Build a vector of twice the length out of the expanded elements. 282 // For example <3 x i64> -> <6 x i32>. 283 std::vector<SDValue> NewElts; 284 NewElts.reserve(NumElts*2); 285 286 for (unsigned i = 0; i < NumElts; ++i) { 287 SDValue Lo, Hi; 288 GetExpandedOp(N->getOperand(i), Lo, Hi); 289 if (TLI.isBigEndian()) 290 std::swap(Lo, Hi); 291 NewElts.push_back(Lo); 292 NewElts.push_back(Hi); 293 } 294 295 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl, 296 MVT::getVectorVT(NewVT, NewElts.size()), 297 &NewElts[0], NewElts.size()); 298 299 // Convert the new vector to the old vector type. 300 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 301} 302 303SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) { 304 SDValue Lo, Hi; 305 GetExpandedOp(N->getOperand(0), Lo, Hi); 306 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo; 307} 308 309SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) { 310 // The vector type is legal but the element type needs expansion. 311 MVT VecVT = N->getValueType(0); 312 unsigned NumElts = VecVT.getVectorNumElements(); 313 DebugLoc dl = N->getDebugLoc(); 314 315 SDValue Val = N->getOperand(1); 316 MVT OldEVT = Val.getValueType(); 317 MVT NewEVT = TLI.getTypeToTransformTo(OldEVT); 318 319 assert(OldEVT == VecVT.getVectorElementType() && 320 "Inserted element type doesn't match vector element type!"); 321 322 // Bitconvert to a vector of twice the length with elements of the expanded 323 // type, insert the expanded vector elements, and then convert back. 324 MVT NewVecVT = MVT::getVectorVT(NewEVT, NumElts*2); 325 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl, 326 NewVecVT, N->getOperand(0)); 327 328 SDValue Lo, Hi; 329 GetExpandedOp(Val, Lo, Hi); 330 if (TLI.isBigEndian()) 331 std::swap(Lo, Hi); 332 333 SDValue Idx = N->getOperand(2); 334 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx); 335 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx); 336 Idx = DAG.getNode(ISD::ADD, dl, 337 Idx.getValueType(), Idx, DAG.getIntPtrConstant(1)); 338 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx); 339 340 // Convert the new vector to the old vector type. 341 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec); 342} 343 344SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) { 345 DebugLoc dl = N->getDebugLoc(); 346 MVT VT = N->getValueType(0); 347 unsigned NumElts = VT.getVectorNumElements(); 348 SmallVector<SDValue, 16> Ops(NumElts); 349 Ops[0] = N->getOperand(0); 350 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType()); 351 for (unsigned i = 1; i < NumElts; ++i) 352 Ops[i] = UndefVal; 353 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts); 354} 355 356SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) { 357 assert(ISD::isNormalStore(N) && "This routine only for normal stores!"); 358 assert(OpNo == 1 && "Can only expand the stored value so far"); 359 DebugLoc dl = N->getDebugLoc(); 360 361 StoreSDNode *St = cast<StoreSDNode>(N); 362 MVT NVT = TLI.getTypeToTransformTo(St->getValue().getValueType()); 363 SDValue Chain = St->getChain(); 364 SDValue Ptr = St->getBasePtr(); 365 int SVOffset = St->getSrcValueOffset(); 366 unsigned Alignment = St->getAlignment(); 367 bool isVolatile = St->isVolatile(); 368 369 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 370 unsigned IncrementSize = NVT.getSizeInBits() / 8; 371 372 SDValue Lo, Hi; 373 GetExpandedOp(St->getValue(), Lo, Hi); 374 375 if (TLI.isBigEndian()) 376 std::swap(Lo, Hi); 377 378 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getSrcValue(), SVOffset, 379 isVolatile, Alignment); 380 381 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, 382 DAG.getIntPtrConstant(IncrementSize)); 383 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!"); 384 Hi = DAG.getStore(Chain, dl, Hi, Ptr, St->getSrcValue(), 385 SVOffset + IncrementSize, 386 isVolatile, MinAlign(Alignment, IncrementSize)); 387 388 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi); 389} 390 391 392//===--------------------------------------------------------------------===// 393// Generic Result Splitting. 394//===--------------------------------------------------------------------===// 395 396// Be careful to make no assumptions about which of Lo/Hi is stored first in 397// memory (for vectors it is always Lo first followed by Hi in the following 398// bytes; for integers and floats it is Lo first if and only if the machine is 399// little-endian). 400 401void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, 402 SDValue &Lo, SDValue &Hi) { 403 // A MERGE_VALUES node can produce any number of values. We know that the 404 // first illegal one needs to be expanded into Lo/Hi. 405 unsigned i; 406 407 // The string of legal results gets turned into input operands, which have 408 // the same type. 409 for (i = 0; isTypeLegal(N->getValueType(i)); ++i) 410 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 411 412 // The first illegal result must be the one that needs to be expanded. 413 GetSplitOp(N->getOperand(i), Lo, Hi); 414 415 // Legalize the rest of the results into the input operands whether they are 416 // legal or not. 417 unsigned e = N->getNumValues(); 418 for (++i; i != e; ++i) 419 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 420} 421 422void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo, 423 SDValue &Hi) { 424 SDValue LL, LH, RL, RH; 425 DebugLoc dl = N->getDebugLoc(); 426 GetSplitOp(N->getOperand(1), LL, LH); 427 GetSplitOp(N->getOperand(2), RL, RH); 428 429 SDValue Cond = N->getOperand(0); 430 Lo = DAG.getNode(ISD::SELECT, dl, LL.getValueType(), Cond, LL, RL); 431 Hi = DAG.getNode(ISD::SELECT, dl, LH.getValueType(), Cond, LH, RH); 432} 433 434void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo, 435 SDValue &Hi) { 436 SDValue LL, LH, RL, RH; 437 DebugLoc dl = N->getDebugLoc(); 438 GetSplitOp(N->getOperand(2), LL, LH); 439 GetSplitOp(N->getOperand(3), RL, RH); 440 441 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0), 442 N->getOperand(1), LL, RL, N->getOperand(4)); 443 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0), 444 N->getOperand(1), LH, RH, N->getOperand(4)); 445} 446 447void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) { 448 MVT LoVT, HiVT; 449 DebugLoc dl = N->getDebugLoc(); 450 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT); 451 Lo = DAG.getUNDEF(LoVT); 452 Hi = DAG.getUNDEF(HiVT); 453} 454