1 //===-------- LegalizeTypesGeneric.cpp - Generic type legalization --------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
20 //===----------------------------------------------------------------------===//
22 #define DEBUG_TYPE "legalize-types"
23 #include "LegalizeTypes.h"
24 #include "llvm/IR/DataLayout.h"
27 //===----------------------------------------------------------------------===//
28 // Generic Result Expansion.
29 //===----------------------------------------------------------------------===//
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 void DAGTypeLegalizer::ExpandRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
35 SDValue &Lo, SDValue &Hi) {
36 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
37 GetExpandedOp(Op, Lo, Hi);
40 void DAGTypeLegalizer::ExpandRes_BITCAST(SDNode *N, SDValue &Lo, SDValue &Hi) {
41 EVT OutVT = N->getValueType(0);
42 EVT NOutVT = TLI.getTypeToTransformTo(*DAG.getContext(), OutVT);
43 SDValue InOp = N->getOperand(0);
44 EVT InVT = InOp.getValueType();
47 // Handle some special cases efficiently.
48 switch (getTypeAction(InVT)) {
49 case TargetLowering::TypeLegal:
50 case TargetLowering::TypePromoteInteger:
52 case TargetLowering::TypeSoftenFloat:
53 // Convert the integer operand instead.
54 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi);
55 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
56 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
58 case TargetLowering::TypeExpandInteger:
59 case TargetLowering::TypeExpandFloat:
60 // Convert the expanded pieces of the input.
61 GetExpandedOp(InOp, Lo, Hi);
62 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
63 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
65 case TargetLowering::TypeSplitVector:
66 GetSplitVector(InOp, Lo, Hi);
67 if (TLI.isBigEndian())
69 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
70 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
72 case TargetLowering::TypeScalarizeVector:
73 // Convert the element instead.
74 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi);
75 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
76 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
78 case TargetLowering::TypeWidenVector: {
79 assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BITCAST");
80 InOp = GetWidenedVector(InOp);
82 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(InVT);
83 std::tie(Lo, Hi) = DAG.SplitVector(InOp, dl, LoVT, HiVT);
84 if (TLI.isBigEndian())
86 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
87 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
92 if (InVT.isVector() && OutVT.isInteger()) {
93 // Handle cases like i64 = BITCAST v1i64 on x86, where the operand
94 // is legal but the result is not.
95 unsigned NumElems = 2;
97 EVT NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
99 // If <ElemVT * N> is not a legal type, try <ElemVT/2 * (N*2)>.
100 while (!isTypeLegal(NVT)) {
101 unsigned NewSizeInBits = ElemVT.getSizeInBits() / 2;
102 // If the element size is smaller than byte, bail.
103 if (NewSizeInBits < 8)
106 ElemVT = EVT::getIntegerVT(*DAG.getContext(), NewSizeInBits);
107 NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
110 if (isTypeLegal(NVT)) {
111 SDValue CastInOp = DAG.getNode(ISD::BITCAST, dl, NVT, InOp);
113 SmallVector<SDValue, 8> Vals;
114 for (unsigned i = 0; i < NumElems; ++i)
115 Vals.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ElemVT,
116 CastInOp, DAG.getConstant(i,
117 TLI.getVectorIdxTy())));
119 // Build Lo, Hi pair by pairing extracted elements if needed.
121 for (unsigned e = Vals.size(); e - Slot > 2; Slot += 2, e += 1) {
122 // Each iteration will BUILD_PAIR two nodes and append the result until
123 // there are only two nodes left, i.e. Lo and Hi.
124 SDValue LHS = Vals[Slot];
125 SDValue RHS = Vals[Slot + 1];
127 if (TLI.isBigEndian())
130 Vals.push_back(DAG.getNode(ISD::BUILD_PAIR, dl,
133 LHS.getValueType().getSizeInBits() << 1),
139 if (TLI.isBigEndian())
146 // Lower the bit-convert to a store/load from the stack.
147 assert(NOutVT.isByteSized() && "Expanded type not byte sized!");
149 // Create the stack frame object. Make sure it is aligned for both
150 // the source and expanded destination types.
152 TLI.getDataLayout()->getPrefTypeAlignment(NOutVT.
153 getTypeForEVT(*DAG.getContext()));
154 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment);
155 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
156 MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI);
158 // Emit a store to the stack slot.
159 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo,
162 // Load the first half from the stack slot.
163 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo,
164 false, false, false, 0);
166 // Increment the pointer to the other half.
167 unsigned IncrementSize = NOutVT.getSizeInBits() / 8;
168 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
169 DAG.getConstant(IncrementSize,
170 StackPtr.getValueType()));
172 // Load the second half from the stack slot.
173 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr,
174 PtrInfo.getWithOffset(IncrementSize), false,
175 false, false, MinAlign(Alignment, IncrementSize));
177 // Handle endianness of the load.
178 if (TLI.isBigEndian())
182 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
184 // Return the operands.
185 Lo = N->getOperand(0);
186 Hi = N->getOperand(1);
189 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
191 GetExpandedOp(N->getOperand(0), Lo, Hi);
192 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
195 assert(Part.getValueType() == N->getValueType(0) &&
196 "Type twice as big as expanded type not itself expanded!");
198 GetPairElements(Part, Lo, Hi);
201 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
203 SDValue OldVec = N->getOperand(0);
204 unsigned OldElts = OldVec.getValueType().getVectorNumElements();
205 EVT OldEltVT = OldVec.getValueType().getVectorElementType();
208 // Convert to a vector of the expanded element type, for example
209 // <3 x i64> -> <6 x i32>.
210 EVT OldVT = N->getValueType(0);
211 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
213 if (OldVT != OldEltVT) {
214 // The result of EXTRACT_VECTOR_ELT may be larger than the element type of
215 // the input vector. If so, extend the elements of the input vector to the
216 // same bitwidth as the result before expanding.
217 assert(OldEltVT.bitsLT(OldVT) && "Result type smaller then element type!");
218 EVT NVecVT = EVT::getVectorVT(*DAG.getContext(), OldVT, OldElts);
219 OldVec = DAG.getNode(ISD::ANY_EXTEND, dl, NVecVT, N->getOperand(0));
222 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
223 EVT::getVectorVT(*DAG.getContext(),
227 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
228 SDValue Idx = N->getOperand(1);
230 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
231 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
233 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
234 DAG.getConstant(1, Idx.getValueType()));
235 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
237 if (TLI.isBigEndian())
241 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
243 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
246 LoadSDNode *LD = cast<LoadSDNode>(N);
247 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), LD->getValueType(0));
248 SDValue Chain = LD->getChain();
249 SDValue Ptr = LD->getBasePtr();
250 unsigned Alignment = LD->getAlignment();
251 bool isVolatile = LD->isVolatile();
252 bool isNonTemporal = LD->isNonTemporal();
253 bool isInvariant = LD->isInvariant();
254 const MDNode *TBAAInfo = LD->getTBAAInfo();
256 assert(NVT.isByteSized() && "Expanded type not byte sized!");
258 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(),
259 isVolatile, isNonTemporal, isInvariant, Alignment,
262 // Increment the pointer to the other half.
263 unsigned IncrementSize = NVT.getSizeInBits() / 8;
264 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
265 DAG.getConstant(IncrementSize, Ptr.getValueType()));
266 Hi = DAG.getLoad(NVT, dl, Chain, Ptr,
267 LD->getPointerInfo().getWithOffset(IncrementSize),
268 isVolatile, isNonTemporal, isInvariant,
269 MinAlign(Alignment, IncrementSize), TBAAInfo);
271 // Build a factor node to remember that this load is independent of the
273 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
276 // Handle endianness of the load.
277 if (TLI.isBigEndian())
280 // Modified the chain - switch anything that used the old chain to use
282 ReplaceValueWith(SDValue(N, 1), Chain);
285 void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) {
286 EVT OVT = N->getValueType(0);
287 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), OVT);
288 SDValue Chain = N->getOperand(0);
289 SDValue Ptr = N->getOperand(1);
291 const unsigned Align = N->getConstantOperandVal(3);
293 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2), Align);
294 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2), 0);
296 // Handle endianness of the load.
297 if (TLI.isBigEndian())
300 // Modified the chain - switch anything that used the old chain to use
302 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
306 //===--------------------------------------------------------------------===//
307 // Generic Operand Expansion.
308 //===--------------------------------------------------------------------===//
310 void DAGTypeLegalizer::IntegerToVector(SDValue Op, unsigned NumElements,
311 SmallVectorImpl<SDValue> &Ops,
313 assert(Op.getValueType().isInteger());
317 if (NumElements > 1) {
319 SplitInteger(Op, Parts[0], Parts[1]);
320 if (TLI.isBigEndian())
321 std::swap(Parts[0], Parts[1]);
322 IntegerToVector(Parts[0], NumElements, Ops, EltVT);
323 IntegerToVector(Parts[1], NumElements, Ops, EltVT);
325 Ops.push_back(DAG.getNode(ISD::BITCAST, DL, EltVT, Op));
329 SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) {
331 if (N->getValueType(0).isVector()) {
332 // An illegal expanding type is being converted to a legal vector type.
333 // Make a two element vector out of the expanded parts and convert that
334 // instead, but only if the new vector type is legal (otherwise there
335 // is no point, and it might create expansion loops). For example, on
336 // x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32.
338 // FIXME: I'm not sure why we are first trying to split the input into
339 // a 2 element vector, so I'm leaving it here to maintain the current
341 unsigned NumElts = 2;
342 EVT OVT = N->getOperand(0).getValueType();
343 EVT NVT = EVT::getVectorVT(*DAG.getContext(),
344 TLI.getTypeToTransformTo(*DAG.getContext(), OVT),
346 if (!isTypeLegal(NVT)) {
347 // If we can't find a legal type by splitting the integer in half,
348 // then we can use the node's value type.
349 NumElts = N->getValueType(0).getVectorNumElements();
350 NVT = N->getValueType(0);
353 SmallVector<SDValue, 8> Ops;
354 IntegerToVector(N->getOperand(0), NumElts, Ops, NVT.getVectorElementType());
356 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, &Ops[0], NumElts);
357 return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec);
360 // Otherwise, store to a temporary and load out again as the new type.
361 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
364 SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
365 // The vector type is legal but the element type needs expansion.
366 EVT VecVT = N->getValueType(0);
367 unsigned NumElts = VecVT.getVectorNumElements();
368 EVT OldVT = N->getOperand(0).getValueType();
369 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
372 assert(OldVT == VecVT.getVectorElementType() &&
373 "BUILD_VECTOR operand type doesn't match vector element type!");
375 // Build a vector of twice the length out of the expanded elements.
376 // For example <3 x i64> -> <6 x i32>.
377 std::vector<SDValue> NewElts;
378 NewElts.reserve(NumElts*2);
380 for (unsigned i = 0; i < NumElts; ++i) {
382 GetExpandedOp(N->getOperand(i), Lo, Hi);
383 if (TLI.isBigEndian())
385 NewElts.push_back(Lo);
386 NewElts.push_back(Hi);
389 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl,
390 EVT::getVectorVT(*DAG.getContext(),
391 NewVT, NewElts.size()),
392 &NewElts[0], NewElts.size());
394 // Convert the new vector to the old vector type.
395 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
398 SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
400 GetExpandedOp(N->getOperand(0), Lo, Hi);
401 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
404 SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) {
405 // The vector type is legal but the element type needs expansion.
406 EVT VecVT = N->getValueType(0);
407 unsigned NumElts = VecVT.getVectorNumElements();
410 SDValue Val = N->getOperand(1);
411 EVT OldEVT = Val.getValueType();
412 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT);
414 assert(OldEVT == VecVT.getVectorElementType() &&
415 "Inserted element type doesn't match vector element type!");
417 // Bitconvert to a vector of twice the length with elements of the expanded
418 // type, insert the expanded vector elements, and then convert back.
419 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2);
420 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
421 NewVecVT, N->getOperand(0));
424 GetExpandedOp(Val, Lo, Hi);
425 if (TLI.isBigEndian())
428 SDValue Idx = N->getOperand(2);
429 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
430 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx);
431 Idx = DAG.getNode(ISD::ADD, dl,
432 Idx.getValueType(), Idx,
433 DAG.getConstant(1, Idx.getValueType()));
434 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx);
436 // Convert the new vector to the old vector type.
437 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
440 SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) {
442 EVT VT = N->getValueType(0);
443 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() &&
444 "SCALAR_TO_VECTOR operand type doesn't match vector element type!");
445 unsigned NumElts = VT.getVectorNumElements();
446 SmallVector<SDValue, 16> Ops(NumElts);
447 Ops[0] = N->getOperand(0);
448 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType());
449 for (unsigned i = 1; i < NumElts; ++i)
451 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts);
454 SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
455 assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
456 assert(OpNo == 1 && "Can only expand the stored value so far");
459 StoreSDNode *St = cast<StoreSDNode>(N);
460 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(),
461 St->getValue().getValueType());
462 SDValue Chain = St->getChain();
463 SDValue Ptr = St->getBasePtr();
464 unsigned Alignment = St->getAlignment();
465 bool isVolatile = St->isVolatile();
466 bool isNonTemporal = St->isNonTemporal();
467 const MDNode *TBAAInfo = St->getTBAAInfo();
469 assert(NVT.isByteSized() && "Expanded type not byte sized!");
470 unsigned IncrementSize = NVT.getSizeInBits() / 8;
473 GetExpandedOp(St->getValue(), Lo, Hi);
475 if (TLI.isBigEndian())
478 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(),
479 isVolatile, isNonTemporal, Alignment, TBAAInfo);
481 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
482 DAG.getConstant(IncrementSize, Ptr.getValueType()));
483 Hi = DAG.getStore(Chain, dl, Hi, Ptr,
484 St->getPointerInfo().getWithOffset(IncrementSize),
485 isVolatile, isNonTemporal,
486 MinAlign(Alignment, IncrementSize), TBAAInfo);
488 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
492 //===--------------------------------------------------------------------===//
493 // Generic Result Splitting.
494 //===--------------------------------------------------------------------===//
496 // Be careful to make no assumptions about which of Lo/Hi is stored first in
497 // memory (for vectors it is always Lo first followed by Hi in the following
498 // bytes; for integers and floats it is Lo first if and only if the machine is
501 void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
502 SDValue &Lo, SDValue &Hi) {
503 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
504 GetSplitOp(Op, Lo, Hi);
507 void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo,
509 SDValue LL, LH, RL, RH, CL, CH;
511 GetSplitOp(N->getOperand(1), LL, LH);
512 GetSplitOp(N->getOperand(2), RL, RH);
514 SDValue Cond = N->getOperand(0);
516 if (Cond.getValueType().isVector()) {
517 // Check if there are already splitted versions of the vector available and
518 // use those instead of splitting the mask operand again.
519 if (getTypeAction(Cond.getValueType()) == TargetLowering::TypeSplitVector)
520 GetSplitVector(Cond, CL, CH);
522 std::tie(CL, CH) = DAG.SplitVector(Cond, dl);
525 Lo = DAG.getNode(N->getOpcode(), dl, LL.getValueType(), CL, LL, RL);
526 Hi = DAG.getNode(N->getOpcode(), dl, LH.getValueType(), CH, LH, RH);
529 void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo,
531 SDValue LL, LH, RL, RH;
533 GetSplitOp(N->getOperand(2), LL, LH);
534 GetSplitOp(N->getOperand(3), RL, RH);
536 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0),
537 N->getOperand(1), LL, RL, N->getOperand(4));
538 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0),
539 N->getOperand(1), LH, RH, N->getOperand(4));
542 void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) {
544 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
545 Lo = DAG.getUNDEF(LoVT);
546 Hi = DAG.getUNDEF(HiVT);