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::TypePromoteFloat:
54 llvm_unreachable("Bitcast of a promotion-needing float should never need"
56 case TargetLowering::TypeSoftenFloat: {
57 // Expand the floating point operand only if it was converted to integers.
58 // Otherwise, it is a legal type like f128 that can be saved in a register.
59 auto SoftenedOp = GetSoftenedFloat(InOp);
60 if (SoftenedOp == InOp)
62 SplitInteger(SoftenedOp, Lo, Hi);
63 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
64 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
67 case TargetLowering::TypeExpandInteger:
68 case TargetLowering::TypeExpandFloat: {
69 auto &DL = DAG.getDataLayout();
70 // Convert the expanded pieces of the input.
71 GetExpandedOp(InOp, Lo, Hi);
72 if (TLI.hasBigEndianPartOrdering(InVT, DL) !=
73 TLI.hasBigEndianPartOrdering(OutVT, DL))
75 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
76 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
79 case TargetLowering::TypeSplitVector:
80 GetSplitVector(InOp, Lo, Hi);
81 if (TLI.hasBigEndianPartOrdering(OutVT, DAG.getDataLayout()))
83 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
84 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
86 case TargetLowering::TypeScalarizeVector:
87 // Convert the element instead.
88 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi);
89 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
90 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
92 case TargetLowering::TypeWidenVector: {
93 assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BITCAST");
94 InOp = GetWidenedVector(InOp);
96 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(InVT);
97 std::tie(Lo, Hi) = DAG.SplitVector(InOp, dl, LoVT, HiVT);
98 if (TLI.hasBigEndianPartOrdering(OutVT, DAG.getDataLayout()))
100 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
101 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
106 if (InVT.isVector() && OutVT.isInteger()) {
107 // Handle cases like i64 = BITCAST v1i64 on x86, where the operand
108 // is legal but the result is not.
109 unsigned NumElems = 2;
111 EVT NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
113 // If <ElemVT * N> is not a legal type, try <ElemVT/2 * (N*2)>.
114 while (!isTypeLegal(NVT)) {
115 unsigned NewSizeInBits = ElemVT.getSizeInBits() / 2;
116 // If the element size is smaller than byte, bail.
117 if (NewSizeInBits < 8)
120 ElemVT = EVT::getIntegerVT(*DAG.getContext(), NewSizeInBits);
121 NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
124 if (isTypeLegal(NVT)) {
125 SDValue CastInOp = DAG.getNode(ISD::BITCAST, dl, NVT, InOp);
127 SmallVector<SDValue, 8> Vals;
128 for (unsigned i = 0; i < NumElems; ++i)
129 Vals.push_back(DAG.getNode(
130 ISD::EXTRACT_VECTOR_ELT, dl, ElemVT, CastInOp,
131 DAG.getConstant(i, dl, TLI.getVectorIdxTy(DAG.getDataLayout()))));
133 // Build Lo, Hi pair by pairing extracted elements if needed.
135 for (unsigned e = Vals.size(); e - Slot > 2; Slot += 2, e += 1) {
136 // Each iteration will BUILD_PAIR two nodes and append the result until
137 // there are only two nodes left, i.e. Lo and Hi.
138 SDValue LHS = Vals[Slot];
139 SDValue RHS = Vals[Slot + 1];
141 if (DAG.getDataLayout().isBigEndian())
144 Vals.push_back(DAG.getNode(ISD::BUILD_PAIR, dl,
147 LHS.getValueType().getSizeInBits() << 1),
153 if (DAG.getDataLayout().isBigEndian())
160 // Lower the bit-convert to a store/load from the stack.
161 assert(NOutVT.isByteSized() && "Expanded type not byte sized!");
163 // Create the stack frame object. Make sure it is aligned for both
164 // the source and expanded destination types.
165 unsigned Alignment = DAG.getDataLayout().getPrefTypeAlignment(
166 NOutVT.getTypeForEVT(*DAG.getContext()));
167 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment);
168 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
169 MachinePointerInfo PtrInfo =
170 MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
172 // Emit a store to the stack slot.
173 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo);
175 // Load the first half from the stack slot.
176 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo);
178 // Increment the pointer to the other half.
179 unsigned IncrementSize = NOutVT.getSizeInBits() / 8;
180 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
181 DAG.getConstant(IncrementSize, dl,
182 StackPtr.getValueType()));
184 // Load the second half from the stack slot.
185 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr,
186 PtrInfo.getWithOffset(IncrementSize),
187 MinAlign(Alignment, IncrementSize));
189 // Handle endianness of the load.
190 if (TLI.hasBigEndianPartOrdering(OutVT, DAG.getDataLayout()))
194 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
196 // Return the operands.
197 Lo = N->getOperand(0);
198 Hi = N->getOperand(1);
201 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
203 GetExpandedOp(N->getOperand(0), Lo, Hi);
204 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
207 assert(Part.getValueType() == N->getValueType(0) &&
208 "Type twice as big as expanded type not itself expanded!");
210 GetPairElements(Part, Lo, Hi);
213 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
215 SDValue OldVec = N->getOperand(0);
216 unsigned OldElts = OldVec.getValueType().getVectorNumElements();
217 EVT OldEltVT = OldVec.getValueType().getVectorElementType();
220 // Convert to a vector of the expanded element type, for example
221 // <3 x i64> -> <6 x i32>.
222 EVT OldVT = N->getValueType(0);
223 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
225 if (OldVT != OldEltVT) {
226 // The result of EXTRACT_VECTOR_ELT may be larger than the element type of
227 // the input vector. If so, extend the elements of the input vector to the
228 // same bitwidth as the result before expanding.
229 assert(OldEltVT.bitsLT(OldVT) && "Result type smaller then element type!");
230 EVT NVecVT = EVT::getVectorVT(*DAG.getContext(), OldVT, OldElts);
231 OldVec = DAG.getNode(ISD::ANY_EXTEND, dl, NVecVT, N->getOperand(0));
234 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
235 EVT::getVectorVT(*DAG.getContext(),
239 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
240 SDValue Idx = N->getOperand(1);
242 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
243 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
245 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
246 DAG.getConstant(1, dl, Idx.getValueType()));
247 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
249 if (DAG.getDataLayout().isBigEndian())
253 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
255 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
258 LoadSDNode *LD = cast<LoadSDNode>(N);
259 EVT ValueVT = LD->getValueType(0);
260 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), ValueVT);
261 SDValue Chain = LD->getChain();
262 SDValue Ptr = LD->getBasePtr();
263 unsigned Alignment = LD->getAlignment();
264 AAMDNodes AAInfo = LD->getAAInfo();
266 assert(NVT.isByteSized() && "Expanded type not byte sized!");
268 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(), Alignment,
269 LD->getMemOperand()->getFlags(), AAInfo);
271 // Increment the pointer to the other half.
272 unsigned IncrementSize = NVT.getSizeInBits() / 8;
273 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
274 DAG.getConstant(IncrementSize, dl, Ptr.getValueType()));
275 Hi = DAG.getLoad(NVT, dl, Chain, Ptr,
276 LD->getPointerInfo().getWithOffset(IncrementSize),
277 MinAlign(Alignment, IncrementSize),
278 LD->getMemOperand()->getFlags(), AAInfo);
280 // Build a factor node to remember that this load is independent of the
282 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
285 // Handle endianness of the load.
286 if (TLI.hasBigEndianPartOrdering(ValueVT, DAG.getDataLayout()))
289 // Modified the chain - switch anything that used the old chain to use
291 ReplaceValueWith(SDValue(N, 1), Chain);
294 void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) {
295 EVT OVT = N->getValueType(0);
296 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), OVT);
297 SDValue Chain = N->getOperand(0);
298 SDValue Ptr = N->getOperand(1);
300 const unsigned Align = N->getConstantOperandVal(3);
302 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2), Align);
303 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2), 0);
305 // Handle endianness of the load.
306 if (TLI.hasBigEndianPartOrdering(OVT, DAG.getDataLayout()))
309 // Modified the chain - switch anything that used the old chain to use
311 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
315 //===--------------------------------------------------------------------===//
316 // Generic Operand Expansion.
317 //===--------------------------------------------------------------------===//
319 void DAGTypeLegalizer::IntegerToVector(SDValue Op, unsigned NumElements,
320 SmallVectorImpl<SDValue> &Ops,
322 assert(Op.getValueType().isInteger());
326 if (NumElements > 1) {
328 SplitInteger(Op, Parts[0], Parts[1]);
329 if (DAG.getDataLayout().isBigEndian())
330 std::swap(Parts[0], Parts[1]);
331 IntegerToVector(Parts[0], NumElements, Ops, EltVT);
332 IntegerToVector(Parts[1], NumElements, Ops, EltVT);
334 Ops.push_back(DAG.getNode(ISD::BITCAST, DL, EltVT, Op));
338 SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) {
340 if (N->getValueType(0).isVector()) {
341 // An illegal expanding type is being converted to a legal vector type.
342 // Make a two element vector out of the expanded parts and convert that
343 // instead, but only if the new vector type is legal (otherwise there
344 // is no point, and it might create expansion loops). For example, on
345 // x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32.
347 // FIXME: I'm not sure why we are first trying to split the input into
348 // a 2 element vector, so I'm leaving it here to maintain the current
350 unsigned NumElts = 2;
351 EVT OVT = N->getOperand(0).getValueType();
352 EVT NVT = EVT::getVectorVT(*DAG.getContext(),
353 TLI.getTypeToTransformTo(*DAG.getContext(), OVT),
355 if (!isTypeLegal(NVT)) {
356 // If we can't find a legal type by splitting the integer in half,
357 // then we can use the node's value type.
358 NumElts = N->getValueType(0).getVectorNumElements();
359 NVT = N->getValueType(0);
362 SmallVector<SDValue, 8> Ops;
363 IntegerToVector(N->getOperand(0), NumElts, Ops, NVT.getVectorElementType());
365 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT,
366 makeArrayRef(Ops.data(), NumElts));
367 return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec);
370 // Otherwise, store to a temporary and load out again as the new type.
371 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
374 SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
375 // The vector type is legal but the element type needs expansion.
376 EVT VecVT = N->getValueType(0);
377 unsigned NumElts = VecVT.getVectorNumElements();
378 EVT OldVT = N->getOperand(0).getValueType();
379 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
382 assert(OldVT == VecVT.getVectorElementType() &&
383 "BUILD_VECTOR operand type doesn't match vector element type!");
385 // Build a vector of twice the length out of the expanded elements.
386 // For example <3 x i64> -> <6 x i32>.
387 std::vector<SDValue> NewElts;
388 NewElts.reserve(NumElts*2);
390 for (unsigned i = 0; i < NumElts; ++i) {
392 GetExpandedOp(N->getOperand(i), Lo, Hi);
393 if (DAG.getDataLayout().isBigEndian())
395 NewElts.push_back(Lo);
396 NewElts.push_back(Hi);
399 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl,
400 EVT::getVectorVT(*DAG.getContext(),
401 NewVT, NewElts.size()),
404 // Convert the new vector to the old vector type.
405 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
408 SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
410 GetExpandedOp(N->getOperand(0), Lo, Hi);
411 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
414 SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) {
415 // The vector type is legal but the element type needs expansion.
416 EVT VecVT = N->getValueType(0);
417 unsigned NumElts = VecVT.getVectorNumElements();
420 SDValue Val = N->getOperand(1);
421 EVT OldEVT = Val.getValueType();
422 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT);
424 assert(OldEVT == VecVT.getVectorElementType() &&
425 "Inserted element type doesn't match vector element type!");
427 // Bitconvert to a vector of twice the length with elements of the expanded
428 // type, insert the expanded vector elements, and then convert back.
429 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2);
430 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
431 NewVecVT, N->getOperand(0));
434 GetExpandedOp(Val, Lo, Hi);
435 if (DAG.getDataLayout().isBigEndian())
438 SDValue Idx = N->getOperand(2);
439 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
440 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx);
441 Idx = DAG.getNode(ISD::ADD, dl,
442 Idx.getValueType(), Idx,
443 DAG.getConstant(1, dl, Idx.getValueType()));
444 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx);
446 // Convert the new vector to the old vector type.
447 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
450 SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) {
452 EVT VT = N->getValueType(0);
453 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() &&
454 "SCALAR_TO_VECTOR operand type doesn't match vector element type!");
455 unsigned NumElts = VT.getVectorNumElements();
456 SmallVector<SDValue, 16> Ops(NumElts);
457 Ops[0] = N->getOperand(0);
458 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType());
459 for (unsigned i = 1; i < NumElts; ++i)
461 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
464 SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
465 assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
466 assert(OpNo == 1 && "Can only expand the stored value so far");
469 StoreSDNode *St = cast<StoreSDNode>(N);
470 EVT ValueVT = St->getValue().getValueType();
471 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), ValueVT);
472 SDValue Chain = St->getChain();
473 SDValue Ptr = St->getBasePtr();
474 unsigned Alignment = St->getAlignment();
475 AAMDNodes AAInfo = St->getAAInfo();
477 assert(NVT.isByteSized() && "Expanded type not byte sized!");
478 unsigned IncrementSize = NVT.getSizeInBits() / 8;
481 GetExpandedOp(St->getValue(), Lo, Hi);
483 if (TLI.hasBigEndianPartOrdering(ValueVT, DAG.getDataLayout()))
486 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(), Alignment,
487 St->getMemOperand()->getFlags(), AAInfo);
489 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
490 DAG.getConstant(IncrementSize, dl, Ptr.getValueType()));
491 Hi = DAG.getStore(Chain, dl, Hi, Ptr,
492 St->getPointerInfo().getWithOffset(IncrementSize),
493 MinAlign(Alignment, IncrementSize),
494 St->getMemOperand()->getFlags(), AAInfo);
496 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
500 //===--------------------------------------------------------------------===//
501 // Generic Result Splitting.
502 //===--------------------------------------------------------------------===//
504 // Be careful to make no assumptions about which of Lo/Hi is stored first in
505 // memory (for vectors it is always Lo first followed by Hi in the following
506 // bytes; for integers and floats it is Lo first if and only if the machine is
509 void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
510 SDValue &Lo, SDValue &Hi) {
511 SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
512 GetSplitOp(Op, Lo, Hi);
515 void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo,
517 SDValue LL, LH, RL, RH, CL, CH;
519 GetSplitOp(N->getOperand(1), LL, LH);
520 GetSplitOp(N->getOperand(2), RL, RH);
522 SDValue Cond = N->getOperand(0);
524 if (Cond.getValueType().isVector()) {
525 // Check if there are already splitted versions of the vector available and
526 // use those instead of splitting the mask operand again.
527 if (getTypeAction(Cond.getValueType()) == TargetLowering::TypeSplitVector)
528 GetSplitVector(Cond, CL, CH);
530 std::tie(CL, CH) = DAG.SplitVector(Cond, dl);
533 Lo = DAG.getNode(N->getOpcode(), dl, LL.getValueType(), CL, LL, RL);
534 Hi = DAG.getNode(N->getOpcode(), dl, LH.getValueType(), CH, LH, RH);
537 void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo,
539 SDValue LL, LH, RL, RH;
541 GetSplitOp(N->getOperand(2), LL, LH);
542 GetSplitOp(N->getOperand(3), RL, RH);
544 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0),
545 N->getOperand(1), LL, RL, N->getOperand(4));
546 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0),
547 N->getOperand(1), LH, RH, N->getOperand(4));
550 void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) {
552 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
553 Lo = DAG.getUNDEF(LoVT);
554 Hi = DAG.getUNDEF(HiVT);