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 #define DEBUG_TYPE "legalize-types"
28 //===----------------------------------------------------------------------===//
29 // Generic Result Expansion.
30 //===----------------------------------------------------------------------===//
32 // These routines assume that the Lo/Hi part is stored first in memory on
33 // little/big-endian machines, followed by the Hi/Lo part. This means that
34 // they cannot be used as is on vectors, for which Lo is always stored first.
35 void DAGTypeLegalizer::ExpandRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
36 SDValue &Lo, SDValue &Hi) {
37 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
38 GetExpandedOp(Op, Lo, Hi);
41 void DAGTypeLegalizer::ExpandRes_BITCAST(SDNode *N, SDValue &Lo, SDValue &Hi) {
42 EVT OutVT = N->getValueType(0);
43 EVT NOutVT = TLI.getTypeToTransformTo(*DAG.getContext(), OutVT);
44 SDValue InOp = N->getOperand(0);
45 EVT InVT = InOp.getValueType();
48 // Handle some special cases efficiently.
49 switch (getTypeAction(InVT)) {
50 case TargetLowering::TypeLegal:
51 case TargetLowering::TypePromoteInteger:
53 case TargetLowering::TypeSoftenFloat:
54 // Convert the integer operand instead.
55 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi);
56 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
57 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
59 case TargetLowering::TypeExpandInteger:
60 case TargetLowering::TypeExpandFloat:
61 // Convert the expanded pieces of the input.
62 GetExpandedOp(InOp, Lo, Hi);
63 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
64 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
66 case TargetLowering::TypeSplitVector:
67 GetSplitVector(InOp, Lo, Hi);
68 if (TLI.isBigEndian())
70 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
71 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
73 case TargetLowering::TypeScalarizeVector:
74 // Convert the element instead.
75 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi);
76 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
77 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
79 case TargetLowering::TypeWidenVector: {
80 assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BITCAST");
81 InOp = GetWidenedVector(InOp);
83 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(InVT);
84 std::tie(Lo, Hi) = DAG.SplitVector(InOp, dl, LoVT, HiVT);
85 if (TLI.isBigEndian())
87 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
88 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
93 if (InVT.isVector() && OutVT.isInteger()) {
94 // Handle cases like i64 = BITCAST v1i64 on x86, where the operand
95 // is legal but the result is not.
96 unsigned NumElems = 2;
98 EVT NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
100 // If <ElemVT * N> is not a legal type, try <ElemVT/2 * (N*2)>.
101 while (!isTypeLegal(NVT)) {
102 unsigned NewSizeInBits = ElemVT.getSizeInBits() / 2;
103 // If the element size is smaller than byte, bail.
104 if (NewSizeInBits < 8)
107 ElemVT = EVT::getIntegerVT(*DAG.getContext(), NewSizeInBits);
108 NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
111 if (isTypeLegal(NVT)) {
112 SDValue CastInOp = DAG.getNode(ISD::BITCAST, dl, NVT, InOp);
114 SmallVector<SDValue, 8> Vals;
115 for (unsigned i = 0; i < NumElems; ++i)
116 Vals.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ElemVT,
117 CastInOp, DAG.getConstant(i,
118 TLI.getVectorIdxTy())));
120 // Build Lo, Hi pair by pairing extracted elements if needed.
122 for (unsigned e = Vals.size(); e - Slot > 2; Slot += 2, e += 1) {
123 // Each iteration will BUILD_PAIR two nodes and append the result until
124 // there are only two nodes left, i.e. Lo and Hi.
125 SDValue LHS = Vals[Slot];
126 SDValue RHS = Vals[Slot + 1];
128 if (TLI.isBigEndian())
131 Vals.push_back(DAG.getNode(ISD::BUILD_PAIR, dl,
134 LHS.getValueType().getSizeInBits() << 1),
140 if (TLI.isBigEndian())
147 // Lower the bit-convert to a store/load from the stack.
148 assert(NOutVT.isByteSized() && "Expanded type not byte sized!");
150 // Create the stack frame object. Make sure it is aligned for both
151 // the source and expanded destination types.
153 TLI.getDataLayout()->getPrefTypeAlignment(NOutVT.
154 getTypeForEVT(*DAG.getContext()));
155 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment);
156 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
157 MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI);
159 // Emit a store to the stack slot.
160 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo,
163 // Load the first half from the stack slot.
164 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo,
165 false, false, false, 0);
167 // Increment the pointer to the other half.
168 unsigned IncrementSize = NOutVT.getSizeInBits() / 8;
169 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
170 DAG.getConstant(IncrementSize,
171 StackPtr.getValueType()));
173 // Load the second half from the stack slot.
174 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr,
175 PtrInfo.getWithOffset(IncrementSize), false,
176 false, false, MinAlign(Alignment, IncrementSize));
178 // Handle endianness of the load.
179 if (TLI.isBigEndian())
183 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
185 // Return the operands.
186 Lo = N->getOperand(0);
187 Hi = N->getOperand(1);
190 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
192 GetExpandedOp(N->getOperand(0), Lo, Hi);
193 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
196 assert(Part.getValueType() == N->getValueType(0) &&
197 "Type twice as big as expanded type not itself expanded!");
199 GetPairElements(Part, Lo, Hi);
202 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
204 SDValue OldVec = N->getOperand(0);
205 unsigned OldElts = OldVec.getValueType().getVectorNumElements();
206 EVT OldEltVT = OldVec.getValueType().getVectorElementType();
209 // Convert to a vector of the expanded element type, for example
210 // <3 x i64> -> <6 x i32>.
211 EVT OldVT = N->getValueType(0);
212 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
214 if (OldVT != OldEltVT) {
215 // The result of EXTRACT_VECTOR_ELT may be larger than the element type of
216 // the input vector. If so, extend the elements of the input vector to the
217 // same bitwidth as the result before expanding.
218 assert(OldEltVT.bitsLT(OldVT) && "Result type smaller then element type!");
219 EVT NVecVT = EVT::getVectorVT(*DAG.getContext(), OldVT, OldElts);
220 OldVec = DAG.getNode(ISD::ANY_EXTEND, dl, NVecVT, N->getOperand(0));
223 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
224 EVT::getVectorVT(*DAG.getContext(),
228 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
229 SDValue Idx = N->getOperand(1);
231 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
232 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
234 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
235 DAG.getConstant(1, Idx.getValueType()));
236 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
238 if (TLI.isBigEndian())
242 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
244 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
247 LoadSDNode *LD = cast<LoadSDNode>(N);
248 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), LD->getValueType(0));
249 SDValue Chain = LD->getChain();
250 SDValue Ptr = LD->getBasePtr();
251 unsigned Alignment = LD->getAlignment();
252 bool isVolatile = LD->isVolatile();
253 bool isNonTemporal = LD->isNonTemporal();
254 bool isInvariant = LD->isInvariant();
255 const MDNode *TBAAInfo = LD->getTBAAInfo();
257 assert(NVT.isByteSized() && "Expanded type not byte sized!");
259 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(),
260 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), TBAAInfo);
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 void DAGTypeLegalizer::IntegerToVector(SDValue Op, unsigned NumElements,
312 SmallVectorImpl<SDValue> &Ops,
314 assert(Op.getValueType().isInteger());
318 if (NumElements > 1) {
320 SplitInteger(Op, Parts[0], Parts[1]);
321 if (TLI.isBigEndian())
322 std::swap(Parts[0], Parts[1]);
323 IntegerToVector(Parts[0], NumElements, Ops, EltVT);
324 IntegerToVector(Parts[1], NumElements, Ops, EltVT);
326 Ops.push_back(DAG.getNode(ISD::BITCAST, DL, EltVT, Op));
330 SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) {
332 if (N->getValueType(0).isVector()) {
333 // An illegal expanding type is being converted to a legal vector type.
334 // Make a two element vector out of the expanded parts and convert that
335 // instead, but only if the new vector type is legal (otherwise there
336 // is no point, and it might create expansion loops). For example, on
337 // x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32.
339 // FIXME: I'm not sure why we are first trying to split the input into
340 // a 2 element vector, so I'm leaving it here to maintain the current
342 unsigned NumElts = 2;
343 EVT OVT = N->getOperand(0).getValueType();
344 EVT NVT = EVT::getVectorVT(*DAG.getContext(),
345 TLI.getTypeToTransformTo(*DAG.getContext(), OVT),
347 if (!isTypeLegal(NVT)) {
348 // If we can't find a legal type by splitting the integer in half,
349 // then we can use the node's value type.
350 NumElts = N->getValueType(0).getVectorNumElements();
351 NVT = N->getValueType(0);
354 SmallVector<SDValue, 8> Ops;
355 IntegerToVector(N->getOperand(0), NumElts, Ops, NVT.getVectorElementType());
357 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, &Ops[0], NumElts);
358 return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec);
361 // Otherwise, store to a temporary and load out again as the new type.
362 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
365 SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
366 // The vector type is legal but the element type needs expansion.
367 EVT VecVT = N->getValueType(0);
368 unsigned NumElts = VecVT.getVectorNumElements();
369 EVT OldVT = N->getOperand(0).getValueType();
370 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
373 assert(OldVT == VecVT.getVectorElementType() &&
374 "BUILD_VECTOR operand type doesn't match vector element type!");
376 // Build a vector of twice the length out of the expanded elements.
377 // For example <3 x i64> -> <6 x i32>.
378 std::vector<SDValue> NewElts;
379 NewElts.reserve(NumElts*2);
381 for (unsigned i = 0; i < NumElts; ++i) {
383 GetExpandedOp(N->getOperand(i), Lo, Hi);
384 if (TLI.isBigEndian())
386 NewElts.push_back(Lo);
387 NewElts.push_back(Hi);
390 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl,
391 EVT::getVectorVT(*DAG.getContext(),
392 NewVT, NewElts.size()),
393 &NewElts[0], NewElts.size());
395 // Convert the new vector to the old vector type.
396 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
399 SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
401 GetExpandedOp(N->getOperand(0), Lo, Hi);
402 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
405 SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) {
406 // The vector type is legal but the element type needs expansion.
407 EVT VecVT = N->getValueType(0);
408 unsigned NumElts = VecVT.getVectorNumElements();
411 SDValue Val = N->getOperand(1);
412 EVT OldEVT = Val.getValueType();
413 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT);
415 assert(OldEVT == VecVT.getVectorElementType() &&
416 "Inserted element type doesn't match vector element type!");
418 // Bitconvert to a vector of twice the length with elements of the expanded
419 // type, insert the expanded vector elements, and then convert back.
420 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2);
421 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
422 NewVecVT, N->getOperand(0));
425 GetExpandedOp(Val, Lo, Hi);
426 if (TLI.isBigEndian())
429 SDValue Idx = N->getOperand(2);
430 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
431 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx);
432 Idx = DAG.getNode(ISD::ADD, dl,
433 Idx.getValueType(), Idx,
434 DAG.getConstant(1, Idx.getValueType()));
435 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx);
437 // Convert the new vector to the old vector type.
438 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
441 SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) {
443 EVT VT = N->getValueType(0);
444 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() &&
445 "SCALAR_TO_VECTOR operand type doesn't match vector element type!");
446 unsigned NumElts = VT.getVectorNumElements();
447 SmallVector<SDValue, 16> Ops(NumElts);
448 Ops[0] = N->getOperand(0);
449 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType());
450 for (unsigned i = 1; i < NumElts; ++i)
452 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts);
455 SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
456 assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
457 assert(OpNo == 1 && "Can only expand the stored value so far");
460 StoreSDNode *St = cast<StoreSDNode>(N);
461 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(),
462 St->getValue().getValueType());
463 SDValue Chain = St->getChain();
464 SDValue Ptr = St->getBasePtr();
465 unsigned Alignment = St->getAlignment();
466 bool isVolatile = St->isVolatile();
467 bool isNonTemporal = St->isNonTemporal();
468 const MDNode *TBAAInfo = St->getTBAAInfo();
470 assert(NVT.isByteSized() && "Expanded type not byte sized!");
471 unsigned IncrementSize = NVT.getSizeInBits() / 8;
474 GetExpandedOp(St->getValue(), Lo, Hi);
476 if (TLI.isBigEndian())
479 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(),
480 isVolatile, isNonTemporal, Alignment, TBAAInfo);
482 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
483 DAG.getConstant(IncrementSize, Ptr.getValueType()));
484 Hi = DAG.getStore(Chain, dl, Hi, Ptr,
485 St->getPointerInfo().getWithOffset(IncrementSize),
486 isVolatile, isNonTemporal,
487 MinAlign(Alignment, IncrementSize), TBAAInfo);
489 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
493 //===--------------------------------------------------------------------===//
494 // Generic Result Splitting.
495 //===--------------------------------------------------------------------===//
497 // Be careful to make no assumptions about which of Lo/Hi is stored first in
498 // memory (for vectors it is always Lo first followed by Hi in the following
499 // bytes; for integers and floats it is Lo first if and only if the machine is
502 void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
503 SDValue &Lo, SDValue &Hi) {
504 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
505 GetSplitOp(Op, Lo, Hi);
508 void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo,
510 SDValue LL, LH, RL, RH, CL, CH;
512 GetSplitOp(N->getOperand(1), LL, LH);
513 GetSplitOp(N->getOperand(2), RL, RH);
515 SDValue Cond = N->getOperand(0);
517 if (Cond.getValueType().isVector()) {
518 // Check if there are already splitted versions of the vector available and
519 // use those instead of splitting the mask operand again.
520 if (getTypeAction(Cond.getValueType()) == TargetLowering::TypeSplitVector)
521 GetSplitVector(Cond, CL, CH);
523 std::tie(CL, CH) = DAG.SplitVector(Cond, dl);
526 Lo = DAG.getNode(N->getOpcode(), dl, LL.getValueType(), CL, LL, RL);
527 Hi = DAG.getNode(N->getOpcode(), dl, LH.getValueType(), CH, LH, RH);
530 void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo,
532 SDValue LL, LH, RL, RH;
534 GetSplitOp(N->getOperand(2), LL, LH);
535 GetSplitOp(N->getOperand(3), RL, RH);
537 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0),
538 N->getOperand(1), LL, RL, N->getOperand(4));
539 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0),
540 N->getOperand(1), LH, RH, N->getOperand(4));
543 void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) {
545 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
546 Lo = DAG.getUNDEF(LoVT);
547 Hi = DAG.getUNDEF(HiVT);