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.getIntPtrConstant(IncrementSize));
174 // Load the second half from the stack slot.
175 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr,
176 PtrInfo.getWithOffset(IncrementSize), false,
177 false, false, MinAlign(Alignment, IncrementSize));
179 // Handle endianness of the load.
180 if (TLI.isBigEndian())
184 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
186 // Return the operands.
187 Lo = N->getOperand(0);
188 Hi = N->getOperand(1);
191 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
193 GetExpandedOp(N->getOperand(0), Lo, Hi);
194 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
197 assert(Part.getValueType() == N->getValueType(0) &&
198 "Type twice as big as expanded type not itself expanded!");
200 GetPairElements(Part, Lo, Hi);
203 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
205 SDValue OldVec = N->getOperand(0);
206 unsigned OldElts = OldVec.getValueType().getVectorNumElements();
207 EVT OldEltVT = OldVec.getValueType().getVectorElementType();
210 // Convert to a vector of the expanded element type, for example
211 // <3 x i64> -> <6 x i32>.
212 EVT OldVT = N->getValueType(0);
213 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
215 if (OldVT != OldEltVT) {
216 // The result of EXTRACT_VECTOR_ELT may be larger than the element type of
217 // the input vector. If so, extend the elements of the input vector to the
218 // same bitwidth as the result before expanding.
219 assert(OldEltVT.bitsLT(OldVT) && "Result type smaller then element type!");
220 EVT NVecVT = EVT::getVectorVT(*DAG.getContext(), OldVT, OldElts);
221 OldVec = DAG.getNode(ISD::ANY_EXTEND, dl, NVecVT, N->getOperand(0));
224 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
225 EVT::getVectorVT(*DAG.getContext(),
229 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
230 SDValue Idx = N->getOperand(1);
232 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
233 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
235 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
236 DAG.getConstant(1, Idx.getValueType()));
237 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
239 if (TLI.isBigEndian())
243 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
245 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
248 LoadSDNode *LD = cast<LoadSDNode>(N);
249 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), LD->getValueType(0));
250 SDValue Chain = LD->getChain();
251 SDValue Ptr = LD->getBasePtr();
252 unsigned Alignment = LD->getAlignment();
253 bool isVolatile = LD->isVolatile();
254 bool isNonTemporal = LD->isNonTemporal();
255 bool isInvariant = LD->isInvariant();
257 assert(NVT.isByteSized() && "Expanded type not byte sized!");
259 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(),
260 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.getIntPtrConstant(IncrementSize));
266 Hi = DAG.getLoad(NVT, dl, Chain, Ptr,
267 LD->getPointerInfo().getWithOffset(IncrementSize),
268 isVolatile, isNonTemporal, isInvariant,
269 MinAlign(Alignment, IncrementSize));
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 SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) {
312 if (N->getValueType(0).isVector()) {
313 // An illegal expanding type is being converted to a legal vector type.
314 // Make a two element vector out of the expanded parts and convert that
315 // instead, but only if the new vector type is legal (otherwise there
316 // is no point, and it might create expansion loops). For example, on
317 // x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32.
318 EVT OVT = N->getOperand(0).getValueType();
319 EVT NVT = EVT::getVectorVT(*DAG.getContext(),
320 TLI.getTypeToTransformTo(*DAG.getContext(), OVT),
323 if (isTypeLegal(NVT)) {
325 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]);
327 if (TLI.isBigEndian())
328 std::swap(Parts[0], Parts[1]);
330 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2);
331 return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec);
335 // Otherwise, store to a temporary and load out again as the new type.
336 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
339 SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
340 // The vector type is legal but the element type needs expansion.
341 EVT VecVT = N->getValueType(0);
342 unsigned NumElts = VecVT.getVectorNumElements();
343 EVT OldVT = N->getOperand(0).getValueType();
344 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
347 assert(OldVT == VecVT.getVectorElementType() &&
348 "BUILD_VECTOR operand type doesn't match vector element type!");
350 // Build a vector of twice the length out of the expanded elements.
351 // For example <3 x i64> -> <6 x i32>.
352 std::vector<SDValue> NewElts;
353 NewElts.reserve(NumElts*2);
355 for (unsigned i = 0; i < NumElts; ++i) {
357 GetExpandedOp(N->getOperand(i), Lo, Hi);
358 if (TLI.isBigEndian())
360 NewElts.push_back(Lo);
361 NewElts.push_back(Hi);
364 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl,
365 EVT::getVectorVT(*DAG.getContext(),
366 NewVT, NewElts.size()),
367 &NewElts[0], NewElts.size());
369 // Convert the new vector to the old vector type.
370 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
373 SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
375 GetExpandedOp(N->getOperand(0), Lo, Hi);
376 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
379 SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) {
380 // The vector type is legal but the element type needs expansion.
381 EVT VecVT = N->getValueType(0);
382 unsigned NumElts = VecVT.getVectorNumElements();
385 SDValue Val = N->getOperand(1);
386 EVT OldEVT = Val.getValueType();
387 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT);
389 assert(OldEVT == VecVT.getVectorElementType() &&
390 "Inserted element type doesn't match vector element type!");
392 // Bitconvert to a vector of twice the length with elements of the expanded
393 // type, insert the expanded vector elements, and then convert back.
394 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2);
395 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
396 NewVecVT, N->getOperand(0));
399 GetExpandedOp(Val, Lo, Hi);
400 if (TLI.isBigEndian())
403 SDValue Idx = N->getOperand(2);
404 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
405 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx);
406 Idx = DAG.getNode(ISD::ADD, dl,
407 Idx.getValueType(), Idx,
408 DAG.getConstant(1, Idx.getValueType()));
409 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx);
411 // Convert the new vector to the old vector type.
412 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
415 SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) {
417 EVT VT = N->getValueType(0);
418 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() &&
419 "SCALAR_TO_VECTOR operand type doesn't match vector element type!");
420 unsigned NumElts = VT.getVectorNumElements();
421 SmallVector<SDValue, 16> Ops(NumElts);
422 Ops[0] = N->getOperand(0);
423 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType());
424 for (unsigned i = 1; i < NumElts; ++i)
426 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts);
429 SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
430 assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
431 assert(OpNo == 1 && "Can only expand the stored value so far");
434 StoreSDNode *St = cast<StoreSDNode>(N);
435 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(),
436 St->getValue().getValueType());
437 SDValue Chain = St->getChain();
438 SDValue Ptr = St->getBasePtr();
439 unsigned Alignment = St->getAlignment();
440 bool isVolatile = St->isVolatile();
441 bool isNonTemporal = St->isNonTemporal();
443 assert(NVT.isByteSized() && "Expanded type not byte sized!");
444 unsigned IncrementSize = NVT.getSizeInBits() / 8;
447 GetExpandedOp(St->getValue(), Lo, Hi);
449 if (TLI.isBigEndian())
452 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(),
453 isVolatile, isNonTemporal, Alignment);
455 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
456 DAG.getIntPtrConstant(IncrementSize));
457 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!");
458 Hi = DAG.getStore(Chain, dl, Hi, Ptr,
459 St->getPointerInfo().getWithOffset(IncrementSize),
460 isVolatile, isNonTemporal,
461 MinAlign(Alignment, IncrementSize));
463 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
467 //===--------------------------------------------------------------------===//
468 // Generic Result Splitting.
469 //===--------------------------------------------------------------------===//
471 // Be careful to make no assumptions about which of Lo/Hi is stored first in
472 // memory (for vectors it is always Lo first followed by Hi in the following
473 // bytes; for integers and floats it is Lo first if and only if the machine is
476 void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
477 SDValue &Lo, SDValue &Hi) {
478 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
479 GetSplitOp(Op, Lo, Hi);
482 void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo,
484 SDValue LL, LH, RL, RH, CL, CH;
486 GetSplitOp(N->getOperand(1), LL, LH);
487 GetSplitOp(N->getOperand(2), RL, RH);
489 SDValue Cond = N->getOperand(0);
491 if (Cond.getValueType().isVector()) {
492 assert(Cond.getValueType().getVectorElementType() == MVT::i1 &&
493 "Condition legalized before result?");
494 unsigned NumElements = Cond.getValueType().getVectorNumElements();
495 EVT VCondTy = EVT::getVectorVT(*DAG.getContext(), MVT::i1, NumElements / 2);
496 CL = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VCondTy, Cond,
497 DAG.getConstant(0, TLI.getVectorIdxTy()));
498 CH = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VCondTy, Cond,
499 DAG.getConstant(NumElements / 2, TLI.getVectorIdxTy()));
502 Lo = DAG.getNode(N->getOpcode(), dl, LL.getValueType(), CL, LL, RL);
503 Hi = DAG.getNode(N->getOpcode(), dl, LH.getValueType(), CH, LH, RH);
506 void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo,
508 SDValue LL, LH, RL, RH;
510 GetSplitOp(N->getOperand(2), LL, LH);
511 GetSplitOp(N->getOperand(3), RL, RH);
513 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0),
514 N->getOperand(1), LL, RL, N->getOperand(4));
515 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0),
516 N->getOperand(1), LH, RH, N->getOperand(4));
519 void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) {
521 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT);
522 Lo = DAG.getUNDEF(LoVT);
523 Hi = DAG.getUNDEF(HiVT);