LegalizeTypesGeneric.cpp revision f6a721c7a51d15f54d103e3f0d9ac2df4cf255c7
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" 21using namespace llvm; 22 23//===----------------------------------------------------------------------===// 24// Generic Result Expansion. 25//===----------------------------------------------------------------------===// 26 27// These routines assume that the Lo/Hi part is stored first in memory on 28// little/big-endian machines, followed by the Hi/Lo part. This means that 29// they cannot be used as is on vectors, for which Lo is always stored first. 30 31void DAGTypeLegalizer::ExpandRes_BIT_CONVERT(SDNode *N, 32 SDOperand &Lo, SDOperand &Hi) { 33 MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0)); 34 SDOperand InOp = N->getOperand(0); 35 MVT InVT = InOp.getValueType(); 36 37 // Handle some special cases efficiently. 38 switch (getTypeAction(InVT)) { 39 default: 40 assert(false && "Unknown type action!"); 41 case Legal: 42 case PromoteInteger: 43 break; 44 case SoftenFloat: 45 // Convert the integer operand instead. 46 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi); 47 Lo = DAG.getNode(ISD::BIT_CONVERT, NVT, Lo); 48 Hi = DAG.getNode(ISD::BIT_CONVERT, NVT, Hi); 49 return; 50 case ExpandInteger: 51 case ExpandFloat: 52 // Convert the expanded pieces of the input. 53 GetExpandedOp(InOp, Lo, Hi); 54 Lo = DAG.getNode(ISD::BIT_CONVERT, NVT, Lo); 55 Hi = DAG.getNode(ISD::BIT_CONVERT, NVT, Hi); 56 return; 57 case Split: 58 // Convert the split parts of the input if it was split in two. 59 GetSplitVector(InOp, Lo, Hi); 60 if (Lo.getValueType() == Hi.getValueType()) { 61 if (TLI.isBigEndian()) 62 std::swap(Lo, Hi); 63 Lo = DAG.getNode(ISD::BIT_CONVERT, NVT, Lo); 64 Hi = DAG.getNode(ISD::BIT_CONVERT, NVT, Hi); 65 return; 66 } 67 break; 68 case Scalarize: 69 // Convert the element instead. 70 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi); 71 Lo = DAG.getNode(ISD::BIT_CONVERT, NVT, Lo); 72 Hi = DAG.getNode(ISD::BIT_CONVERT, NVT, Hi); 73 return; 74 } 75 76 // Lower the bit-convert to a store/load from the stack, then expand the load. 77 SDOperand Op = CreateStackStoreLoad(InOp, N->getValueType(0)); 78 ExpandRes_NormalLoad(Op.Val, Lo, Hi); 79} 80 81void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, 82 SDOperand &Lo, SDOperand &Hi) { 83 // Return the operands. 84 Lo = N->getOperand(0); 85 Hi = N->getOperand(1); 86} 87 88void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, 89 SDOperand &Lo, 90 SDOperand &Hi) { 91 SDOperand OldVec = N->getOperand(0); 92 unsigned OldElts = OldVec.getValueType().getVectorNumElements(); 93 94 // Convert to a vector of the expanded element type, for example 95 // <3 x i64> -> <6 x i32>. 96 MVT OldVT = N->getValueType(0); 97 MVT NewVT = TLI.getTypeToTransformTo(OldVT); 98 99 SDOperand NewVec = DAG.getNode(ISD::BIT_CONVERT, 100 MVT::getVectorVT(NewVT, 2*OldElts), 101 OldVec); 102 103 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector. 104 SDOperand Idx = N->getOperand(1); 105 106 // Make sure the type of Idx is big enough to hold the new values. 107 if (Idx.getValueType().bitsLT(TLI.getPointerTy())) 108 Idx = DAG.getNode(ISD::ZERO_EXTEND, TLI.getPointerTy(), Idx); 109 110 Idx = DAG.getNode(ISD::ADD, Idx.getValueType(), Idx, Idx); 111 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, NewVT, NewVec, Idx); 112 113 Idx = DAG.getNode(ISD::ADD, Idx.getValueType(), Idx, 114 DAG.getConstant(1, Idx.getValueType())); 115 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, NewVT, NewVec, Idx); 116 117 if (TLI.isBigEndian()) 118 std::swap(Lo, Hi); 119} 120 121void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDOperand &Lo, 122 SDOperand &Hi) { 123 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!"); 124 125 LoadSDNode *LD = cast<LoadSDNode>(N); 126 MVT NVT = TLI.getTypeToTransformTo(LD->getValueType(0)); 127 SDOperand Chain = LD->getChain(); 128 SDOperand Ptr = LD->getBasePtr(); 129 int SVOffset = LD->getSrcValueOffset(); 130 unsigned Alignment = LD->getAlignment(); 131 bool isVolatile = LD->isVolatile(); 132 133 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 134 135 Lo = DAG.getLoad(NVT, Chain, Ptr, LD->getSrcValue(), SVOffset, 136 isVolatile, Alignment); 137 138 // Increment the pointer to the other half. 139 unsigned IncrementSize = NVT.getSizeInBits() / 8; 140 Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr, 141 DAG.getIntPtrConstant(IncrementSize)); 142 Hi = DAG.getLoad(NVT, Chain, Ptr, LD->getSrcValue(), SVOffset+IncrementSize, 143 isVolatile, MinAlign(Alignment, IncrementSize)); 144 145 // Build a factor node to remember that this load is independent of the 146 // other one. 147 Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, Lo.getValue(1), 148 Hi.getValue(1)); 149 150 // Handle endianness of the load. 151 if (TLI.isBigEndian()) 152 std::swap(Lo, Hi); 153 154 // Modified the chain - switch anything that used the old chain to use 155 // the new one. 156 ReplaceValueWith(SDOperand(N, 1), Chain); 157} 158 159//===--------------------------------------------------------------------===// 160// Generic Operand Expansion. 161//===--------------------------------------------------------------------===// 162 163SDOperand DAGTypeLegalizer::ExpandOp_BIT_CONVERT(SDNode *N) { 164 if (N->getValueType(0).isVector()) { 165 // An illegal expanding type is being converted to a legal vector type. 166 // Make a two element vector out of the expanded parts and convert that 167 // instead, but only if the new vector type is legal (otherwise there 168 // is no point, and it might create expansion loops). For example, on 169 // x86 this turns v1i64 = BIT_CONVERT i64 into v1i64 = BIT_CONVERT v2i32. 170 MVT OVT = N->getOperand(0).getValueType(); 171 MVT NVT = MVT::getVectorVT(TLI.getTypeToTransformTo(OVT), 2); 172 173 if (isTypeLegal(NVT)) { 174 SDOperand Parts[2]; 175 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]); 176 177 if (TLI.isBigEndian()) 178 std::swap(Parts[0], Parts[1]); 179 180 SDOperand Vec = DAG.getNode(ISD::BUILD_VECTOR, NVT, Parts, 2); 181 return DAG.getNode(ISD::BIT_CONVERT, N->getValueType(0), Vec); 182 } 183 } 184 185 // Otherwise, store to a temporary and load out again as the new type. 186 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0)); 187} 188 189SDOperand DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) { 190 // The vector type is legal but the element type needs expansion. 191 MVT VecVT = N->getValueType(0); 192 unsigned NumElts = VecVT.getVectorNumElements(); 193 MVT OldVT = N->getOperand(0).getValueType(); 194 MVT NewVT = TLI.getTypeToTransformTo(OldVT); 195 196 // Build a vector of twice the length out of the expanded elements. 197 // For example <3 x i64> -> <6 x i32>. 198 std::vector<SDOperand> NewElts; 199 NewElts.reserve(NumElts*2); 200 201 for (unsigned i = 0; i < NumElts; ++i) { 202 SDOperand Lo, Hi; 203 GetExpandedOp(N->getOperand(i), Lo, Hi); 204 if (TLI.isBigEndian()) 205 std::swap(Lo, Hi); 206 NewElts.push_back(Lo); 207 NewElts.push_back(Hi); 208 } 209 210 SDOperand NewVec = DAG.getNode(ISD::BUILD_VECTOR, 211 MVT::getVectorVT(NewVT, NewElts.size()), 212 &NewElts[0], NewElts.size()); 213 214 // Convert the new vector to the old vector type. 215 return DAG.getNode(ISD::BIT_CONVERT, VecVT, NewVec); 216} 217 218SDOperand DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) { 219 SDOperand Lo, Hi; 220 GetExpandedOp(N->getOperand(0), Lo, Hi); 221 return cast<ConstantSDNode>(N->getOperand(1))->getValue() ? Hi : Lo; 222} 223 224SDOperand DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) { 225 assert(ISD::isNormalStore(N) && "This routine only for normal stores!"); 226 assert(OpNo == 1 && "Can only expand the stored value so far"); 227 228 StoreSDNode *St = cast<StoreSDNode>(N); 229 MVT NVT = TLI.getTypeToTransformTo(St->getValue().getValueType()); 230 SDOperand Chain = St->getChain(); 231 SDOperand Ptr = St->getBasePtr(); 232 int SVOffset = St->getSrcValueOffset(); 233 unsigned Alignment = St->getAlignment(); 234 bool isVolatile = St->isVolatile(); 235 236 assert(NVT.isByteSized() && "Expanded type not byte sized!"); 237 unsigned IncrementSize = NVT.getSizeInBits() / 8; 238 239 SDOperand Lo, Hi; 240 GetExpandedOp(St->getValue(), Lo, Hi); 241 242 if (TLI.isBigEndian()) 243 std::swap(Lo, Hi); 244 245 Lo = DAG.getStore(Chain, Lo, Ptr, St->getSrcValue(), SVOffset, 246 isVolatile, Alignment); 247 248 Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr, 249 DAG.getIntPtrConstant(IncrementSize)); 250 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!"); 251 Hi = DAG.getStore(Chain, Hi, Ptr, St->getSrcValue(), SVOffset + IncrementSize, 252 isVolatile, MinAlign(Alignment, IncrementSize)); 253 254 return DAG.getNode(ISD::TokenFactor, MVT::Other, Lo, Hi); 255} 256 257 258//===--------------------------------------------------------------------===// 259// Generic Result Splitting. 260//===--------------------------------------------------------------------===// 261 262// Be careful to make no assumptions about which of Lo/Hi is stored first in 263// memory (for vectors it is always Lo first followed by Hi in the following 264// bytes; for integers and floats it is Lo first if and only if the machine is 265// little-endian). 266 267void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, 268 SDOperand &Lo, SDOperand &Hi) { 269 // A MERGE_VALUES node can produce any number of values. We know that the 270 // first illegal one needs to be expanded into Lo/Hi. 271 unsigned i; 272 273 // The string of legal results gets turns into the input operands, which have 274 // the same type. 275 for (i = 0; isTypeLegal(N->getValueType(i)); ++i) 276 ReplaceValueWith(SDOperand(N, i), SDOperand(N->getOperand(i))); 277 278 // The first illegal result must be the one that needs to be expanded. 279 GetSplitOp(N->getOperand(i), Lo, Hi); 280 281 // Legalize the rest of the results into the input operands whether they are 282 // legal or not. 283 unsigned e = N->getNumValues(); 284 for (++i; i != e; ++i) 285 ReplaceValueWith(SDOperand(N, i), SDOperand(N->getOperand(i))); 286} 287 288void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDOperand &Lo, 289 SDOperand &Hi) { 290 SDOperand LL, LH, RL, RH; 291 GetSplitOp(N->getOperand(1), LL, LH); 292 GetSplitOp(N->getOperand(2), RL, RH); 293 294 SDOperand Cond = N->getOperand(0); 295 Lo = DAG.getNode(ISD::SELECT, LL.getValueType(), Cond, LL, RL); 296 Hi = DAG.getNode(ISD::SELECT, LH.getValueType(), Cond, LH, RH); 297} 298 299void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDOperand &Lo, 300 SDOperand &Hi) { 301 SDOperand LL, LH, RL, RH; 302 GetSplitOp(N->getOperand(2), LL, LH); 303 GetSplitOp(N->getOperand(3), RL, RH); 304 305 Lo = DAG.getNode(ISD::SELECT_CC, LL.getValueType(), N->getOperand(0), 306 N->getOperand(1), LL, RL, N->getOperand(4)); 307 Hi = DAG.getNode(ISD::SELECT_CC, LH.getValueType(), N->getOperand(0), 308 N->getOperand(1), LH, RH, N->getOperand(4)); 309} 310 311void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDOperand &Lo, SDOperand &Hi) { 312 MVT LoVT, HiVT; 313 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT); 314 Lo = DAG.getNode(ISD::UNDEF, LoVT); 315 Hi = DAG.getNode(ISD::UNDEF, HiVT); 316} 317