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 // Convert the integer operand instead.
58 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi);
59 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
60 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
62 case TargetLowering::TypeExpandInteger:
63 case TargetLowering::TypeExpandFloat:
64 // Convert the expanded pieces of the input.
65 GetExpandedOp(InOp, Lo, Hi);
66 if (TLI.hasBigEndianPartOrdering(InVT) !=
67 TLI.hasBigEndianPartOrdering(OutVT))
69 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
70 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
72 case TargetLowering::TypeSplitVector:
73 GetSplitVector(InOp, Lo, Hi);
74 if (TLI.hasBigEndianPartOrdering(OutVT))
76 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
77 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
79 case TargetLowering::TypeScalarizeVector:
80 // Convert the element instead.
81 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi);
82 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
83 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
85 case TargetLowering::TypeWidenVector: {
86 assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BITCAST");
87 InOp = GetWidenedVector(InOp);
89 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(InVT);
90 std::tie(Lo, Hi) = DAG.SplitVector(InOp, dl, LoVT, HiVT);
91 if (TLI.hasBigEndianPartOrdering(OutVT))
93 Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
94 Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
99 if (InVT.isVector() && OutVT.isInteger()) {
100 // Handle cases like i64 = BITCAST v1i64 on x86, where the operand
101 // is legal but the result is not.
102 unsigned NumElems = 2;
104 EVT NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
106 // If <ElemVT * N> is not a legal type, try <ElemVT/2 * (N*2)>.
107 while (!isTypeLegal(NVT)) {
108 unsigned NewSizeInBits = ElemVT.getSizeInBits() / 2;
109 // If the element size is smaller than byte, bail.
110 if (NewSizeInBits < 8)
113 ElemVT = EVT::getIntegerVT(*DAG.getContext(), NewSizeInBits);
114 NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
117 if (isTypeLegal(NVT)) {
118 SDValue CastInOp = DAG.getNode(ISD::BITCAST, dl, NVT, InOp);
120 SmallVector<SDValue, 8> Vals;
121 for (unsigned i = 0; i < NumElems; ++i)
122 Vals.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ElemVT,
123 CastInOp, DAG.getConstant(i, dl,
124 TLI.getVectorIdxTy())));
126 // Build Lo, Hi pair by pairing extracted elements if needed.
128 for (unsigned e = Vals.size(); e - Slot > 2; Slot += 2, e += 1) {
129 // Each iteration will BUILD_PAIR two nodes and append the result until
130 // there are only two nodes left, i.e. Lo and Hi.
131 SDValue LHS = Vals[Slot];
132 SDValue RHS = Vals[Slot + 1];
134 if (DAG.getDataLayout().isBigEndian())
137 Vals.push_back(DAG.getNode(ISD::BUILD_PAIR, dl,
140 LHS.getValueType().getSizeInBits() << 1),
146 if (DAG.getDataLayout().isBigEndian())
153 // Lower the bit-convert to a store/load from the stack.
154 assert(NOutVT.isByteSized() && "Expanded type not byte sized!");
156 // Create the stack frame object. Make sure it is aligned for both
157 // the source and expanded destination types.
158 unsigned Alignment = DAG.getDataLayout().getPrefTypeAlignment(
159 NOutVT.getTypeForEVT(*DAG.getContext()));
160 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment);
161 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
162 MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI);
164 // Emit a store to the stack slot.
165 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo,
168 // Load the first half from the stack slot.
169 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo,
170 false, false, false, 0);
172 // Increment the pointer to the other half.
173 unsigned IncrementSize = NOutVT.getSizeInBits() / 8;
174 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
175 DAG.getConstant(IncrementSize, dl,
176 StackPtr.getValueType()));
178 // Load the second half from the stack slot.
179 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr,
180 PtrInfo.getWithOffset(IncrementSize), false,
181 false, false, MinAlign(Alignment, IncrementSize));
183 // Handle endianness of the load.
184 if (TLI.hasBigEndianPartOrdering(OutVT))
188 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
190 // Return the operands.
191 Lo = N->getOperand(0);
192 Hi = N->getOperand(1);
195 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
197 GetExpandedOp(N->getOperand(0), Lo, Hi);
198 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
201 assert(Part.getValueType() == N->getValueType(0) &&
202 "Type twice as big as expanded type not itself expanded!");
204 GetPairElements(Part, Lo, Hi);
207 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
209 SDValue OldVec = N->getOperand(0);
210 unsigned OldElts = OldVec.getValueType().getVectorNumElements();
211 EVT OldEltVT = OldVec.getValueType().getVectorElementType();
214 // Convert to a vector of the expanded element type, for example
215 // <3 x i64> -> <6 x i32>.
216 EVT OldVT = N->getValueType(0);
217 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
219 if (OldVT != OldEltVT) {
220 // The result of EXTRACT_VECTOR_ELT may be larger than the element type of
221 // the input vector. If so, extend the elements of the input vector to the
222 // same bitwidth as the result before expanding.
223 assert(OldEltVT.bitsLT(OldVT) && "Result type smaller then element type!");
224 EVT NVecVT = EVT::getVectorVT(*DAG.getContext(), OldVT, OldElts);
225 OldVec = DAG.getNode(ISD::ANY_EXTEND, dl, NVecVT, N->getOperand(0));
228 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
229 EVT::getVectorVT(*DAG.getContext(),
233 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
234 SDValue Idx = N->getOperand(1);
236 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
237 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
239 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
240 DAG.getConstant(1, dl, Idx.getValueType()));
241 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
243 if (DAG.getDataLayout().isBigEndian())
247 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
249 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
252 LoadSDNode *LD = cast<LoadSDNode>(N);
253 EVT ValueVT = LD->getValueType(0);
254 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), ValueVT);
255 SDValue Chain = LD->getChain();
256 SDValue Ptr = LD->getBasePtr();
257 unsigned Alignment = LD->getAlignment();
258 bool isVolatile = LD->isVolatile();
259 bool isNonTemporal = LD->isNonTemporal();
260 bool isInvariant = LD->isInvariant();
261 AAMDNodes AAInfo = LD->getAAInfo();
263 assert(NVT.isByteSized() && "Expanded type not byte sized!");
265 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(),
266 isVolatile, isNonTemporal, isInvariant, Alignment,
269 // Increment the pointer to the other half.
270 unsigned IncrementSize = NVT.getSizeInBits() / 8;
271 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
272 DAG.getConstant(IncrementSize, dl, Ptr.getValueType()));
273 Hi = DAG.getLoad(NVT, dl, Chain, Ptr,
274 LD->getPointerInfo().getWithOffset(IncrementSize),
275 isVolatile, isNonTemporal, isInvariant,
276 MinAlign(Alignment, IncrementSize), AAInfo);
278 // Build a factor node to remember that this load is independent of the
280 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
283 // Handle endianness of the load.
284 if (TLI.hasBigEndianPartOrdering(ValueVT))
287 // Modified the chain - switch anything that used the old chain to use
289 ReplaceValueWith(SDValue(N, 1), Chain);
292 void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) {
293 EVT OVT = N->getValueType(0);
294 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), OVT);
295 SDValue Chain = N->getOperand(0);
296 SDValue Ptr = N->getOperand(1);
298 const unsigned Align = N->getConstantOperandVal(3);
300 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2), Align);
301 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2), 0);
303 // Handle endianness of the load.
304 if (TLI.hasBigEndianPartOrdering(OVT))
307 // Modified the chain - switch anything that used the old chain to use
309 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
313 //===--------------------------------------------------------------------===//
314 // Generic Operand Expansion.
315 //===--------------------------------------------------------------------===//
317 void DAGTypeLegalizer::IntegerToVector(SDValue Op, unsigned NumElements,
318 SmallVectorImpl<SDValue> &Ops,
320 assert(Op.getValueType().isInteger());
324 if (NumElements > 1) {
326 SplitInteger(Op, Parts[0], Parts[1]);
327 if (DAG.getDataLayout().isBigEndian())
328 std::swap(Parts[0], Parts[1]);
329 IntegerToVector(Parts[0], NumElements, Ops, EltVT);
330 IntegerToVector(Parts[1], NumElements, Ops, EltVT);
332 Ops.push_back(DAG.getNode(ISD::BITCAST, DL, EltVT, Op));
336 SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) {
338 if (N->getValueType(0).isVector()) {
339 // An illegal expanding type is being converted to a legal vector type.
340 // Make a two element vector out of the expanded parts and convert that
341 // instead, but only if the new vector type is legal (otherwise there
342 // is no point, and it might create expansion loops). For example, on
343 // x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32.
345 // FIXME: I'm not sure why we are first trying to split the input into
346 // a 2 element vector, so I'm leaving it here to maintain the current
348 unsigned NumElts = 2;
349 EVT OVT = N->getOperand(0).getValueType();
350 EVT NVT = EVT::getVectorVT(*DAG.getContext(),
351 TLI.getTypeToTransformTo(*DAG.getContext(), OVT),
353 if (!isTypeLegal(NVT)) {
354 // If we can't find a legal type by splitting the integer in half,
355 // then we can use the node's value type.
356 NumElts = N->getValueType(0).getVectorNumElements();
357 NVT = N->getValueType(0);
360 SmallVector<SDValue, 8> Ops;
361 IntegerToVector(N->getOperand(0), NumElts, Ops, NVT.getVectorElementType());
363 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT,
364 makeArrayRef(Ops.data(), NumElts));
365 return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec);
368 // Otherwise, store to a temporary and load out again as the new type.
369 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
372 SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
373 // The vector type is legal but the element type needs expansion.
374 EVT VecVT = N->getValueType(0);
375 unsigned NumElts = VecVT.getVectorNumElements();
376 EVT OldVT = N->getOperand(0).getValueType();
377 EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
380 assert(OldVT == VecVT.getVectorElementType() &&
381 "BUILD_VECTOR operand type doesn't match vector element type!");
383 // Build a vector of twice the length out of the expanded elements.
384 // For example <3 x i64> -> <6 x i32>.
385 std::vector<SDValue> NewElts;
386 NewElts.reserve(NumElts*2);
388 for (unsigned i = 0; i < NumElts; ++i) {
390 GetExpandedOp(N->getOperand(i), Lo, Hi);
391 if (DAG.getDataLayout().isBigEndian())
393 NewElts.push_back(Lo);
394 NewElts.push_back(Hi);
397 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl,
398 EVT::getVectorVT(*DAG.getContext(),
399 NewVT, NewElts.size()),
402 // Convert the new vector to the old vector type.
403 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
406 SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
408 GetExpandedOp(N->getOperand(0), Lo, Hi);
409 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
412 SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) {
413 // The vector type is legal but the element type needs expansion.
414 EVT VecVT = N->getValueType(0);
415 unsigned NumElts = VecVT.getVectorNumElements();
418 SDValue Val = N->getOperand(1);
419 EVT OldEVT = Val.getValueType();
420 EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT);
422 assert(OldEVT == VecVT.getVectorElementType() &&
423 "Inserted element type doesn't match vector element type!");
425 // Bitconvert to a vector of twice the length with elements of the expanded
426 // type, insert the expanded vector elements, and then convert back.
427 EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2);
428 SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
429 NewVecVT, N->getOperand(0));
432 GetExpandedOp(Val, Lo, Hi);
433 if (DAG.getDataLayout().isBigEndian())
436 SDValue Idx = N->getOperand(2);
437 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
438 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx);
439 Idx = DAG.getNode(ISD::ADD, dl,
440 Idx.getValueType(), Idx,
441 DAG.getConstant(1, dl, Idx.getValueType()));
442 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx);
444 // Convert the new vector to the old vector type.
445 return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
448 SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) {
450 EVT VT = N->getValueType(0);
451 assert(VT.getVectorElementType() == N->getOperand(0).getValueType() &&
452 "SCALAR_TO_VECTOR operand type doesn't match vector element type!");
453 unsigned NumElts = VT.getVectorNumElements();
454 SmallVector<SDValue, 16> Ops(NumElts);
455 Ops[0] = N->getOperand(0);
456 SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType());
457 for (unsigned i = 1; i < NumElts; ++i)
459 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
462 SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
463 assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
464 assert(OpNo == 1 && "Can only expand the stored value so far");
467 StoreSDNode *St = cast<StoreSDNode>(N);
468 EVT ValueVT = St->getValue().getValueType();
469 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), ValueVT);
470 SDValue Chain = St->getChain();
471 SDValue Ptr = St->getBasePtr();
472 unsigned Alignment = St->getAlignment();
473 bool isVolatile = St->isVolatile();
474 bool isNonTemporal = St->isNonTemporal();
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))
486 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(),
487 isVolatile, isNonTemporal, Alignment, 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 isVolatile, isNonTemporal,
494 MinAlign(Alignment, IncrementSize), 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);