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);
80 EVT InNVT = EVT::getVectorVT(*DAG.getContext(), InVT.getVectorElementType(),
81 InVT.getVectorNumElements()/2);
82 Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, InNVT, InOp,
83 DAG.getConstant(0, TLI.getVectorIdxTy()));
84 Hi = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, InNVT, InOp,
85 DAG.getConstant(InNVT.getVectorNumElements(),
86 TLI.getVectorIdxTy()));
87 if (TLI.isBigEndian())
89 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
90 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
95 if (InVT.isVector() && OutVT.isInteger()) {
96 // Handle cases like i64 = BITCAST v1i64 on x86, where the operand
97 // is legal but the result is not.
98 unsigned NumElems = 2;
100 EVT NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
102 // If <ElemVT * N> is not a legal type, try <ElemVT/2 * (N*2)>.
103 while (!isTypeLegal(NVT)) {
104 unsigned NewSizeInBits = ElemVT.getSizeInBits() / 2;
105 // If the element size is smaller than byte, bail.
106 if (NewSizeInBits < 8)
109 ElemVT = EVT::getIntegerVT(*DAG.getContext(), NewSizeInBits);
110 NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
113 if (isTypeLegal(NVT)) {
114 SDValue CastInOp = DAG.getNode(ISD::BITCAST, dl, NVT, InOp);
116 SmallVector<SDValue, 8> Vals;
117 for (unsigned i = 0; i < NumElems; ++i)
118 Vals.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ElemVT,
119 CastInOp, DAG.getConstant(i,
120 TLI.getVectorIdxTy())));
122 // Build Lo, Hi pair by pairing extracted elements if needed.
124 for (unsigned e = Vals.size(); e - Slot > 2; Slot += 2, e += 1) {
125 // Each iteration will BUILD_PAIR two nodes and append the result until
126 // there are only two nodes left, i.e. Lo and Hi.
127 SDValue LHS = Vals[Slot];
128 SDValue RHS = Vals[Slot + 1];
130 if (TLI.isBigEndian())
133 Vals.push_back(DAG.getNode(ISD::BUILD_PAIR, dl,
136 LHS.getValueType().getSizeInBits() << 1),
142 if (TLI.isBigEndian())
149 // Lower the bit-convert to a store/load from the stack.
150 assert(NOutVT.isByteSized() && "Expanded type not byte sized!");
152 // Create the stack frame object. Make sure it is aligned for both
153 // the source and expanded destination types.
155 TLI.getDataLayout()->getPrefTypeAlignment(NOutVT.
156 getTypeForEVT(*DAG.getContext()));
157 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment);
158 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
159 MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI);
161 // Emit a store to the stack slot.
162 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo,
165 // Load the first half from the stack slot.
166 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo,
167 false, false, false, 0);
169 // Increment the pointer to the other half.
170 unsigned IncrementSize = NOutVT.getSizeInBits() / 8;
171 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
172 DAG.getConstant(IncrementSize,
173 StackPtr.getValueType()));
175 // Load the second half from the stack slot.
176 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr,
177 PtrInfo.getWithOffset(IncrementSize), false,
178 false, false, MinAlign(Alignment, IncrementSize));
180 // Handle endianness of the load.
181 if (TLI.isBigEndian())
185 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
187 // Return the operands.
188 Lo = N->getOperand(0);
189 Hi = N->getOperand(1);
192 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
194 GetExpandedOp(N->getOperand(0), Lo, Hi);
195 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
198 assert(Part.getValueType() == N->getValueType(0) &&
199 "Type twice as big as expanded type not itself expanded!");
201 GetPairElements(Part, Lo, Hi);
204 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
206 SDValue OldVec = N->getOperand(0);
207 unsigned OldElts = OldVec.getValueType().getVectorNumElements();
208 EVT OldEltVT = OldVec.getValueType().getVectorElementType();
211 // Convert to a vector of the expanded element type, for example
212 // <3 x i64> -> <6 x i32>.
213 EVT OldVT = N->getValueType(0);
214 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
216 if (OldVT != OldEltVT) {
217 // The result of EXTRACT_VECTOR_ELT may be larger than the element type of
218 // the input vector. If so, extend the elements of the input vector to the
219 // same bitwidth as the result before expanding.
220 assert(OldEltVT.bitsLT(OldVT) && "Result type smaller then element type!");
221 EVT NVecVT = EVT::getVectorVT(*DAG.getContext(), OldVT, OldElts);
222 OldVec = DAG.getNode(ISD::ANY_EXTEND, dl, NVecVT, N->getOperand(0));
225 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
226 EVT::getVectorVT(*DAG.getContext(),
230 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
231 SDValue Idx = N->getOperand(1);
233 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
234 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
236 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
237 DAG.getConstant(1, Idx.getValueType()));
238 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
240 if (TLI.isBigEndian())
244 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
246 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
249 LoadSDNode *LD = cast<LoadSDNode>(N);
250 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), LD->getValueType(0));
251 SDValue Chain = LD->getChain();
252 SDValue Ptr = LD->getBasePtr();
253 unsigned Alignment = LD->getAlignment();
254 bool isVolatile = LD->isVolatile();
255 bool isNonTemporal = LD->isNonTemporal();
256 bool isInvariant = LD->isInvariant();
258 assert(NVT.isByteSized() && "Expanded type not byte sized!");
260 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(),
261 isVolatile, isNonTemporal, isInvariant, Alignment);
263 // Increment the pointer to the other half.
264 unsigned IncrementSize = NVT.getSizeInBits() / 8;
265 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
266 DAG.getConstant(IncrementSize, Ptr.getValueType()));
267 Hi = DAG.getLoad(NVT, dl, Chain, Ptr,
268 LD->getPointerInfo().getWithOffset(IncrementSize),
269 isVolatile, isNonTemporal, isInvariant,
270 MinAlign(Alignment, IncrementSize));
272 // Build a factor node to remember that this load is independent of the
274 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
277 // Handle endianness of the load.
278 if (TLI.isBigEndian())
281 // Modified the chain - switch anything that used the old chain to use
283 ReplaceValueWith(SDValue(N, 1), Chain);
286 void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) {
287 EVT OVT = N->getValueType(0);
288 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), OVT);
289 SDValue Chain = N->getOperand(0);
290 SDValue Ptr = N->getOperand(1);
292 const unsigned Align = N->getConstantOperandVal(3);
294 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2), Align);
295 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2), 0);
297 // Handle endianness of the load.
298 if (TLI.isBigEndian())
301 // Modified the chain - switch anything that used the old chain to use
303 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
307 //===--------------------------------------------------------------------===//
308 // Generic Operand Expansion.
309 //===--------------------------------------------------------------------===//
311 SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) {
313 if (N->getValueType(0).isVector()) {
314 // An illegal expanding type is being converted to a legal vector type.
315 // Make a two element vector out of the expanded parts and convert that
316 // instead, but only if the new vector type is legal (otherwise there
317 // is no point, and it might create expansion loops). For example, on
318 // x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32.
319 EVT OVT = N->getOperand(0).getValueType();
320 EVT NVT = EVT::getVectorVT(*DAG.getContext(),
321 TLI.getTypeToTransformTo(*DAG.getContext(), OVT),
324 if (isTypeLegal(NVT)) {
326 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]);
328 if (TLI.isBigEndian())
329 std::swap(Parts[0], Parts[1]);
331 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2);
332 return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec);
336 // Otherwise, store to a temporary and load out again as the new type.
337 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
340 SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
341 // The vector type is legal but the element type needs expansion.
342 EVT VecVT = N->getValueType(0);
343 unsigned NumElts = VecVT.getVectorNumElements();
344 EVT OldVT = N->getOperand(0).getValueType();
345 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
348 assert(OldVT == VecVT.getVectorElementType() &&
349 "BUILD_VECTOR operand type doesn't match vector element type!");
351 // Build a vector of twice the length out of the expanded elements.
352 // For example <3 x i64> -> <6 x i32>.
353 std::vector<SDValue> NewElts;
354 NewElts.reserve(NumElts*2);
356 for (unsigned i = 0; i < NumElts; ++i) {
358 GetExpandedOp(N->getOperand(i), Lo, Hi);
359 if (TLI.isBigEndian())
361 NewElts.push_back(Lo);
362 NewElts.push_back(Hi);
365 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl,
366 EVT::getVectorVT(*DAG.getContext(),
367 NewVT, NewElts.size()),
368 &NewElts[0], NewElts.size());
370 // Convert the new vector to the old vector type.
371 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
374 SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
376 GetExpandedOp(N->getOperand(0), Lo, Hi);
377 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
380 SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) {
381 // The vector type is legal but the element type needs expansion.
382 EVT VecVT = N->getValueType(0);
383 unsigned NumElts = VecVT.getVectorNumElements();
386 SDValue Val = N->getOperand(1);
387 EVT OldEVT = Val.getValueType();
388 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT);
390 assert(OldEVT == VecVT.getVectorElementType() &&
391 "Inserted element type doesn't match vector element type!");
393 // Bitconvert to a vector of twice the length with elements of the expanded
394 // type, insert the expanded vector elements, and then convert back.
395 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2);
396 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
397 NewVecVT, N->getOperand(0));
400 GetExpandedOp(Val, Lo, Hi);
401 if (TLI.isBigEndian())
404 SDValue Idx = N->getOperand(2);
405 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
406 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx);
407 Idx = DAG.getNode(ISD::ADD, dl,
408 Idx.getValueType(), Idx,
409 DAG.getConstant(1, Idx.getValueType()));
410 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx);
412 // Convert the new vector to the old vector type.
413 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
416 SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) {
418 EVT VT = N->getValueType(0);
419 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() &&
420 "SCALAR_TO_VECTOR operand type doesn't match vector element type!");
421 unsigned NumElts = VT.getVectorNumElements();
422 SmallVector<SDValue, 16> Ops(NumElts);
423 Ops[0] = N->getOperand(0);
424 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType());
425 for (unsigned i = 1; i < NumElts; ++i)
427 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts);
430 SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
431 assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
432 assert(OpNo == 1 && "Can only expand the stored value so far");
435 StoreSDNode *St = cast<StoreSDNode>(N);
436 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(),
437 St->getValue().getValueType());
438 SDValue Chain = St->getChain();
439 SDValue Ptr = St->getBasePtr();
440 unsigned Alignment = St->getAlignment();
441 bool isVolatile = St->isVolatile();
442 bool isNonTemporal = St->isNonTemporal();
444 assert(NVT.isByteSized() && "Expanded type not byte sized!");
445 unsigned IncrementSize = NVT.getSizeInBits() / 8;
448 GetExpandedOp(St->getValue(), Lo, Hi);
450 if (TLI.isBigEndian())
453 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(),
454 isVolatile, isNonTemporal, Alignment);
456 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
457 DAG.getConstant(IncrementSize, Ptr.getValueType()));
458 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!");
459 Hi = DAG.getStore(Chain, dl, Hi, Ptr,
460 St->getPointerInfo().getWithOffset(IncrementSize),
461 isVolatile, isNonTemporal,
462 MinAlign(Alignment, IncrementSize));
464 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
468 //===--------------------------------------------------------------------===//
469 // Generic Result Splitting.
470 //===--------------------------------------------------------------------===//
472 // Be careful to make no assumptions about which of Lo/Hi is stored first in
473 // memory (for vectors it is always Lo first followed by Hi in the following
474 // bytes; for integers and floats it is Lo first if and only if the machine is
477 void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
478 SDValue &Lo, SDValue &Hi) {
479 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
480 GetSplitOp(Op, Lo, Hi);
483 void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo,
485 SDValue LL, LH, RL, RH, CL, CH;
487 GetSplitOp(N->getOperand(1), LL, LH);
488 GetSplitOp(N->getOperand(2), RL, RH);
490 SDValue Cond = N->getOperand(0);
492 if (Cond.getValueType().isVector()) {
493 assert(Cond.getValueType().getVectorElementType() == MVT::i1 &&
494 "Condition legalized before result?");
495 unsigned NumElements = Cond.getValueType().getVectorNumElements();
496 EVT VCondTy = EVT::getVectorVT(*DAG.getContext(), MVT::i1, NumElements / 2);
497 CL = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VCondTy, Cond,
498 DAG.getConstant(0, TLI.getVectorIdxTy()));
499 CH = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VCondTy, Cond,
500 DAG.getConstant(NumElements / 2, TLI.getVectorIdxTy()));
503 Lo = DAG.getNode(N->getOpcode(), dl, LL.getValueType(), CL, LL, RL);
504 Hi = DAG.getNode(N->getOpcode(), dl, LH.getValueType(), CH, LH, RH);
507 void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo,
509 SDValue LL, LH, RL, RH;
511 GetSplitOp(N->getOperand(2), LL, LH);
512 GetSplitOp(N->getOperand(3), RL, RH);
514 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0),
515 N->getOperand(1), LL, RL, N->getOperand(4));
516 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0),
517 N->getOperand(1), LH, RH, N->getOperand(4));
520 void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) {
522 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT);
523 Lo = DAG.getUNDEF(LoVT);
524 Hi = DAG.getUNDEF(HiVT);