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 #include "LegalizeTypes.h"
23 #include "llvm/IR/DataLayout.h"
26 //===----------------------------------------------------------------------===//
27 // Generic Result Expansion.
28 //===----------------------------------------------------------------------===//
30 // These routines assume that the Lo/Hi part is stored first in memory on
31 // little/big-endian machines, followed by the Hi/Lo part. This means that
32 // they cannot be used as is on vectors, for which Lo is always stored first.
33 void DAGTypeLegalizer::ExpandRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
34 SDValue &Lo, SDValue &Hi) {
35 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
36 GetExpandedOp(Op, Lo, Hi);
39 void DAGTypeLegalizer::ExpandRes_BITCAST(SDNode *N, SDValue &Lo, SDValue &Hi) {
40 EVT OutVT = N->getValueType(0);
41 EVT NOutVT = TLI.getTypeToTransformTo(*DAG.getContext(), OutVT);
42 SDValue InOp = N->getOperand(0);
43 EVT InVT = InOp.getValueType();
46 // Handle some special cases efficiently.
47 switch (getTypeAction(InVT)) {
48 case TargetLowering::TypeLegal:
49 case TargetLowering::TypePromoteInteger:
51 case TargetLowering::TypeSoftenFloat:
52 // Convert the integer operand instead.
53 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi);
54 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
55 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
57 case TargetLowering::TypeExpandInteger:
58 case TargetLowering::TypeExpandFloat:
59 // Convert the expanded pieces of the input.
60 GetExpandedOp(InOp, Lo, Hi);
61 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
62 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
64 case TargetLowering::TypeSplitVector:
65 GetSplitVector(InOp, Lo, Hi);
66 if (TLI.isBigEndian())
68 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
69 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
71 case TargetLowering::TypeScalarizeVector:
72 // Convert the element instead.
73 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi);
74 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
75 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
77 case TargetLowering::TypeWidenVector: {
78 assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BITCAST");
79 InOp = GetWidenedVector(InOp);
81 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(InVT);
82 std::tie(Lo, Hi) = DAG.SplitVector(InOp, dl, LoVT, HiVT);
83 if (TLI.isBigEndian())
85 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
86 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
91 if (InVT.isVector() && OutVT.isInteger()) {
92 // Handle cases like i64 = BITCAST v1i64 on x86, where the operand
93 // is legal but the result is not.
94 unsigned NumElems = 2;
96 EVT NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
98 // If <ElemVT * N> is not a legal type, try <ElemVT/2 * (N*2)>.
99 while (!isTypeLegal(NVT)) {
100 unsigned NewSizeInBits = ElemVT.getSizeInBits() / 2;
101 // If the element size is smaller than byte, bail.
102 if (NewSizeInBits < 8)
105 ElemVT = EVT::getIntegerVT(*DAG.getContext(), NewSizeInBits);
106 NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
109 if (isTypeLegal(NVT)) {
110 SDValue CastInOp = DAG.getNode(ISD::BITCAST, dl, NVT, InOp);
112 SmallVector<SDValue, 8> Vals;
113 for (unsigned i = 0; i < NumElems; ++i)
114 Vals.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ElemVT,
115 CastInOp, DAG.getConstant(i,
116 TLI.getVectorIdxTy())));
118 // Build Lo, Hi pair by pairing extracted elements if needed.
120 for (unsigned e = Vals.size(); e - Slot > 2; Slot += 2, e += 1) {
121 // Each iteration will BUILD_PAIR two nodes and append the result until
122 // there are only two nodes left, i.e. Lo and Hi.
123 SDValue LHS = Vals[Slot];
124 SDValue RHS = Vals[Slot + 1];
126 if (TLI.isBigEndian())
129 Vals.push_back(DAG.getNode(ISD::BUILD_PAIR, dl,
132 LHS.getValueType().getSizeInBits() << 1),
138 if (TLI.isBigEndian())
145 // Lower the bit-convert to a store/load from the stack.
146 assert(NOutVT.isByteSized() && "Expanded type not byte sized!");
148 // Create the stack frame object. Make sure it is aligned for both
149 // the source and expanded destination types.
151 TLI.getDataLayout()->getPrefTypeAlignment(NOutVT.
152 getTypeForEVT(*DAG.getContext()));
153 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment);
154 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
155 MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI);
157 // Emit a store to the stack slot.
158 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo,
161 // Load the first half from the stack slot.
162 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo,
163 false, false, false, 0);
165 // Increment the pointer to the other half.
166 unsigned IncrementSize = NOutVT.getSizeInBits() / 8;
167 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
168 DAG.getConstant(IncrementSize,
169 StackPtr.getValueType()));
171 // Load the second half from the stack slot.
172 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr,
173 PtrInfo.getWithOffset(IncrementSize), false,
174 false, false, MinAlign(Alignment, IncrementSize));
176 // Handle endianness of the load.
177 if (TLI.isBigEndian())
181 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
183 // Return the operands.
184 Lo = N->getOperand(0);
185 Hi = N->getOperand(1);
188 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
190 GetExpandedOp(N->getOperand(0), Lo, Hi);
191 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
194 assert(Part.getValueType() == N->getValueType(0) &&
195 "Type twice as big as expanded type not itself expanded!");
197 GetPairElements(Part, Lo, Hi);
200 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
202 SDValue OldVec = N->getOperand(0);
203 unsigned OldElts = OldVec.getValueType().getVectorNumElements();
204 EVT OldEltVT = OldVec.getValueType().getVectorElementType();
207 // Convert to a vector of the expanded element type, for example
208 // <3 x i64> -> <6 x i32>.
209 EVT OldVT = N->getValueType(0);
210 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
212 if (OldVT != OldEltVT) {
213 // The result of EXTRACT_VECTOR_ELT may be larger than the element type of
214 // the input vector. If so, extend the elements of the input vector to the
215 // same bitwidth as the result before expanding.
216 assert(OldEltVT.bitsLT(OldVT) && "Result type smaller then element type!");
217 EVT NVecVT = EVT::getVectorVT(*DAG.getContext(), OldVT, OldElts);
218 OldVec = DAG.getNode(ISD::ANY_EXTEND, dl, NVecVT, N->getOperand(0));
221 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
222 EVT::getVectorVT(*DAG.getContext(),
226 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
227 SDValue Idx = N->getOperand(1);
229 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
230 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
232 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
233 DAG.getConstant(1, Idx.getValueType()));
234 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
236 if (TLI.isBigEndian())
240 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
242 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
245 LoadSDNode *LD = cast<LoadSDNode>(N);
246 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), LD->getValueType(0));
247 SDValue Chain = LD->getChain();
248 SDValue Ptr = LD->getBasePtr();
249 unsigned Alignment = LD->getAlignment();
250 bool isVolatile = LD->isVolatile();
251 bool isNonTemporal = LD->isNonTemporal();
252 bool isInvariant = LD->isInvariant();
253 const MDNode *TBAAInfo = LD->getTBAAInfo();
255 assert(NVT.isByteSized() && "Expanded type not byte sized!");
257 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(),
258 isVolatile, isNonTemporal, isInvariant, Alignment,
261 // Increment the pointer to the other half.
262 unsigned IncrementSize = NVT.getSizeInBits() / 8;
263 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
264 DAG.getConstant(IncrementSize, Ptr.getValueType()));
265 Hi = DAG.getLoad(NVT, dl, Chain, Ptr,
266 LD->getPointerInfo().getWithOffset(IncrementSize),
267 isVolatile, isNonTemporal, isInvariant,
268 MinAlign(Alignment, IncrementSize), TBAAInfo);
270 // Build a factor node to remember that this load is independent of the
272 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
275 // Handle endianness of the load.
276 if (TLI.isBigEndian())
279 // Modified the chain - switch anything that used the old chain to use
281 ReplaceValueWith(SDValue(N, 1), Chain);
284 void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) {
285 EVT OVT = N->getValueType(0);
286 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), OVT);
287 SDValue Chain = N->getOperand(0);
288 SDValue Ptr = N->getOperand(1);
290 const unsigned Align = N->getConstantOperandVal(3);
292 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2), Align);
293 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2), 0);
295 // Handle endianness of the load.
296 if (TLI.isBigEndian())
299 // Modified the chain - switch anything that used the old chain to use
301 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
305 //===--------------------------------------------------------------------===//
306 // Generic Operand Expansion.
307 //===--------------------------------------------------------------------===//
309 void DAGTypeLegalizer::IntegerToVector(SDValue Op, unsigned NumElements,
310 SmallVectorImpl<SDValue> &Ops,
312 assert(Op.getValueType().isInteger());
316 if (NumElements > 1) {
318 SplitInteger(Op, Parts[0], Parts[1]);
319 if (TLI.isBigEndian())
320 std::swap(Parts[0], Parts[1]);
321 IntegerToVector(Parts[0], NumElements, Ops, EltVT);
322 IntegerToVector(Parts[1], NumElements, Ops, EltVT);
324 Ops.push_back(DAG.getNode(ISD::BITCAST, DL, EltVT, Op));
328 SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) {
330 if (N->getValueType(0).isVector()) {
331 // An illegal expanding type is being converted to a legal vector type.
332 // Make a two element vector out of the expanded parts and convert that
333 // instead, but only if the new vector type is legal (otherwise there
334 // is no point, and it might create expansion loops). For example, on
335 // x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32.
337 // FIXME: I'm not sure why we are first trying to split the input into
338 // a 2 element vector, so I'm leaving it here to maintain the current
340 unsigned NumElts = 2;
341 EVT OVT = N->getOperand(0).getValueType();
342 EVT NVT = EVT::getVectorVT(*DAG.getContext(),
343 TLI.getTypeToTransformTo(*DAG.getContext(), OVT),
345 if (!isTypeLegal(NVT)) {
346 // If we can't find a legal type by splitting the integer in half,
347 // then we can use the node's value type.
348 NumElts = N->getValueType(0).getVectorNumElements();
349 NVT = N->getValueType(0);
352 SmallVector<SDValue, 8> Ops;
353 IntegerToVector(N->getOperand(0), NumElts, Ops, NVT.getVectorElementType());
355 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, &Ops[0], NumElts);
356 return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec);
359 // Otherwise, store to a temporary and load out again as the new type.
360 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
363 SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
364 // The vector type is legal but the element type needs expansion.
365 EVT VecVT = N->getValueType(0);
366 unsigned NumElts = VecVT.getVectorNumElements();
367 EVT OldVT = N->getOperand(0).getValueType();
368 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
371 assert(OldVT == VecVT.getVectorElementType() &&
372 "BUILD_VECTOR operand type doesn't match vector element type!");
374 // Build a vector of twice the length out of the expanded elements.
375 // For example <3 x i64> -> <6 x i32>.
376 std::vector<SDValue> NewElts;
377 NewElts.reserve(NumElts*2);
379 for (unsigned i = 0; i < NumElts; ++i) {
381 GetExpandedOp(N->getOperand(i), Lo, Hi);
382 if (TLI.isBigEndian())
384 NewElts.push_back(Lo);
385 NewElts.push_back(Hi);
388 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl,
389 EVT::getVectorVT(*DAG.getContext(),
390 NewVT, NewElts.size()),
391 &NewElts[0], NewElts.size());
393 // Convert the new vector to the old vector type.
394 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
397 SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
399 GetExpandedOp(N->getOperand(0), Lo, Hi);
400 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
403 SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) {
404 // The vector type is legal but the element type needs expansion.
405 EVT VecVT = N->getValueType(0);
406 unsigned NumElts = VecVT.getVectorNumElements();
409 SDValue Val = N->getOperand(1);
410 EVT OldEVT = Val.getValueType();
411 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT);
413 assert(OldEVT == VecVT.getVectorElementType() &&
414 "Inserted element type doesn't match vector element type!");
416 // Bitconvert to a vector of twice the length with elements of the expanded
417 // type, insert the expanded vector elements, and then convert back.
418 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2);
419 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
420 NewVecVT, N->getOperand(0));
423 GetExpandedOp(Val, Lo, Hi);
424 if (TLI.isBigEndian())
427 SDValue Idx = N->getOperand(2);
428 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
429 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx);
430 Idx = DAG.getNode(ISD::ADD, dl,
431 Idx.getValueType(), Idx,
432 DAG.getConstant(1, Idx.getValueType()));
433 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx);
435 // Convert the new vector to the old vector type.
436 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
439 SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) {
441 EVT VT = N->getValueType(0);
442 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() &&
443 "SCALAR_TO_VECTOR operand type doesn't match vector element type!");
444 unsigned NumElts = VT.getVectorNumElements();
445 SmallVector<SDValue, 16> Ops(NumElts);
446 Ops[0] = N->getOperand(0);
447 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType());
448 for (unsigned i = 1; i < NumElts; ++i)
450 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts);
453 SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
454 assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
455 assert(OpNo == 1 && "Can only expand the stored value so far");
458 StoreSDNode *St = cast<StoreSDNode>(N);
459 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(),
460 St->getValue().getValueType());
461 SDValue Chain = St->getChain();
462 SDValue Ptr = St->getBasePtr();
463 unsigned Alignment = St->getAlignment();
464 bool isVolatile = St->isVolatile();
465 bool isNonTemporal = St->isNonTemporal();
466 const MDNode *TBAAInfo = St->getTBAAInfo();
468 assert(NVT.isByteSized() && "Expanded type not byte sized!");
469 unsigned IncrementSize = NVT.getSizeInBits() / 8;
472 GetExpandedOp(St->getValue(), Lo, Hi);
474 if (TLI.isBigEndian())
477 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(),
478 isVolatile, isNonTemporal, Alignment, TBAAInfo);
480 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
481 DAG.getConstant(IncrementSize, Ptr.getValueType()));
482 Hi = DAG.getStore(Chain, dl, Hi, Ptr,
483 St->getPointerInfo().getWithOffset(IncrementSize),
484 isVolatile, isNonTemporal,
485 MinAlign(Alignment, IncrementSize), TBAAInfo);
487 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
491 //===--------------------------------------------------------------------===//
492 // Generic Result Splitting.
493 //===--------------------------------------------------------------------===//
495 // Be careful to make no assumptions about which of Lo/Hi is stored first in
496 // memory (for vectors it is always Lo first followed by Hi in the following
497 // bytes; for integers and floats it is Lo first if and only if the machine is
500 void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
501 SDValue &Lo, SDValue &Hi) {
502 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
503 GetSplitOp(Op, Lo, Hi);
506 void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo,
508 SDValue LL, LH, RL, RH, CL, CH;
510 GetSplitOp(N->getOperand(1), LL, LH);
511 GetSplitOp(N->getOperand(2), RL, RH);
513 SDValue Cond = N->getOperand(0);
515 if (Cond.getValueType().isVector()) {
516 // Check if there are already splitted versions of the vector available and
517 // use those instead of splitting the mask operand again.
518 if (getTypeAction(Cond.getValueType()) == TargetLowering::TypeSplitVector)
519 GetSplitVector(Cond, CL, CH);
521 std::tie(CL, CH) = DAG.SplitVector(Cond, dl);
524 Lo = DAG.getNode(N->getOpcode(), dl, LL.getValueType(), CL, LL, RL);
525 Hi = DAG.getNode(N->getOpcode(), dl, LH.getValueType(), CH, LH, RH);
528 void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo,
530 SDValue LL, LH, RL, RH;
532 GetSplitOp(N->getOperand(2), LL, LH);
533 GetSplitOp(N->getOperand(3), RL, RH);
535 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0),
536 N->getOperand(1), LL, RL, N->getOperand(4));
537 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0),
538 N->getOperand(1), LH, RH, N->getOperand(4));
541 void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) {
543 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
544 Lo = DAG.getUNDEF(LoVT);
545 Hi = DAG.getUNDEF(HiVT);