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.
15 // Splitting is the act of changing a computation in an illegal type to be a
16 // computation in two not necessarily identical registers of a smaller type.
18 //===----------------------------------------------------------------------===//
20 #include "LegalizeTypes.h"
21 #include "llvm/Target/TargetData.h"
22 #include "llvm/CodeGen/PseudoSourceValue.h"
25 //===----------------------------------------------------------------------===//
26 // Generic Result Expansion.
27 //===----------------------------------------------------------------------===//
29 // These routines assume that the Lo/Hi part is stored first in memory on
30 // little/big-endian machines, followed by the Hi/Lo part. This means that
31 // they cannot be used as is on vectors, for which Lo is always stored first.
33 void DAGTypeLegalizer::ExpandRes_BIT_CONVERT(SDNode *N, SDValue &Lo,
35 MVT OutVT = N->getValueType(0);
36 MVT NOutVT = TLI.getTypeToTransformTo(OutVT);
37 SDValue InOp = N->getOperand(0);
38 MVT InVT = InOp.getValueType();
39 DebugLoc dl = N->getDebugLoc();
41 // Handle some special cases efficiently.
42 switch (getTypeAction(InVT)) {
44 assert(false && "Unknown type action!");
49 // Convert the integer operand instead.
50 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi);
51 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo);
52 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi);
56 // Convert the expanded pieces of the input.
57 GetExpandedOp(InOp, Lo, Hi);
58 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo);
59 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi);
62 // Convert the split parts of the input if it was split in two.
63 GetSplitVector(InOp, Lo, Hi);
64 if (Lo.getValueType() == Hi.getValueType()) {
65 if (TLI.isBigEndian())
67 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo);
68 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi);
73 // Convert the element instead.
74 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi);
75 Lo = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Lo);
76 Hi = DAG.getNode(ISD::BIT_CONVERT, dl, NOutVT, Hi);
80 // Lower the bit-convert to a store/load from the stack.
81 assert(NOutVT.isByteSized() && "Expanded type not byte sized!");
83 // Create the stack frame object. Make sure it is aligned for both
84 // the source and expanded destination types.
86 TLI.getTargetData()->getPrefTypeAlignment(NOutVT.getTypeForMVT());
87 SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment);
88 int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
89 const Value *SV = PseudoSourceValue::getFixedStack(SPFI);
91 // Emit a store to the stack slot.
92 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, SV, 0);
94 // Load the first half from the stack slot.
95 Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, SV, 0);
97 // Increment the pointer to the other half.
98 unsigned IncrementSize = NOutVT.getSizeInBits() / 8;
99 StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
100 DAG.getIntPtrConstant(IncrementSize));
102 // Load the second half from the stack slot.
103 Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr, SV, IncrementSize, false,
104 MinAlign(Alignment, IncrementSize));
106 // Handle endianness of the load.
107 if (TLI.isBigEndian())
111 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
113 // Return the operands.
114 Lo = N->getOperand(0);
115 Hi = N->getOperand(1);
118 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
120 GetExpandedOp(N->getOperand(0), Lo, Hi);
121 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
123 DebugLoc dl = N->getDebugLoc();
125 assert(Part.getValueType() == N->getValueType(0) &&
126 "Type twice as big as expanded type not itself expanded!");
127 MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
129 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Part,
130 DAG.getConstant(0, TLI.getPointerTy()));
131 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Part,
132 DAG.getConstant(1, TLI.getPointerTy()));
135 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
137 SDValue OldVec = N->getOperand(0);
138 unsigned OldElts = OldVec.getValueType().getVectorNumElements();
139 DebugLoc dl = N->getDebugLoc();
141 // Convert to a vector of the expanded element type, for example
142 // <3 x i64> -> <6 x i32>.
143 MVT OldVT = N->getValueType(0);
144 MVT NewVT = TLI.getTypeToTransformTo(OldVT);
146 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl,
147 MVT::getVectorVT(NewVT, 2*OldElts),
150 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
151 SDValue Idx = N->getOperand(1);
153 // Make sure the type of Idx is big enough to hold the new values.
154 if (Idx.getValueType().bitsLT(TLI.getPointerTy()))
155 Idx = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Idx);
157 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
158 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
160 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
161 DAG.getConstant(1, Idx.getValueType()));
162 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
164 if (TLI.isBigEndian())
168 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
170 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
171 DebugLoc dl = N->getDebugLoc();
173 LoadSDNode *LD = cast<LoadSDNode>(N);
174 MVT NVT = TLI.getTypeToTransformTo(LD->getValueType(0));
175 SDValue Chain = LD->getChain();
176 SDValue Ptr = LD->getBasePtr();
177 int SVOffset = LD->getSrcValueOffset();
178 unsigned Alignment = LD->getAlignment();
179 bool isVolatile = LD->isVolatile();
181 assert(NVT.isByteSized() && "Expanded type not byte sized!");
183 Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getSrcValue(), SVOffset,
184 isVolatile, Alignment);
186 // Increment the pointer to the other half.
187 unsigned IncrementSize = NVT.getSizeInBits() / 8;
188 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
189 DAG.getIntPtrConstant(IncrementSize));
190 Hi = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getSrcValue(),
191 SVOffset+IncrementSize,
192 isVolatile, MinAlign(Alignment, IncrementSize));
194 // Build a factor node to remember that this load is independent of the
196 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
199 // Handle endianness of the load.
200 if (TLI.isBigEndian())
203 // Modified the chain - switch anything that used the old chain to use
205 ReplaceValueWith(SDValue(N, 1), Chain);
208 void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) {
209 MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
210 SDValue Chain = N->getOperand(0);
211 SDValue Ptr = N->getOperand(1);
212 DebugLoc dl = N->getDebugLoc();
214 Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2));
215 Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2));
217 // Handle endianness of the load.
218 if (TLI.isBigEndian())
221 // Modified the chain - switch anything that used the old chain to use
223 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
227 //===--------------------------------------------------------------------===//
228 // Generic Operand Expansion.
229 //===--------------------------------------------------------------------===//
231 SDValue DAGTypeLegalizer::ExpandOp_BIT_CONVERT(SDNode *N) {
232 DebugLoc dl = N->getDebugLoc();
233 if (N->getValueType(0).isVector()) {
234 // An illegal expanding type is being converted to a legal vector type.
235 // Make a two element vector out of the expanded parts and convert that
236 // instead, but only if the new vector type is legal (otherwise there
237 // is no point, and it might create expansion loops). For example, on
238 // x86 this turns v1i64 = BIT_CONVERT i64 into v1i64 = BIT_CONVERT v2i32.
239 MVT OVT = N->getOperand(0).getValueType();
240 MVT NVT = MVT::getVectorVT(TLI.getTypeToTransformTo(OVT), 2);
242 if (isTypeLegal(NVT)) {
244 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]);
246 if (TLI.isBigEndian())
247 std::swap(Parts[0], Parts[1]);
249 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Parts, 2);
250 return DAG.getNode(ISD::BIT_CONVERT, dl, N->getValueType(0), Vec);
254 // Otherwise, store to a temporary and load out again as the new type.
255 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
258 SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
259 // The vector type is legal but the element type needs expansion.
260 MVT VecVT = N->getValueType(0);
261 unsigned NumElts = VecVT.getVectorNumElements();
262 MVT OldVT = N->getOperand(0).getValueType();
263 MVT NewVT = TLI.getTypeToTransformTo(OldVT);
264 DebugLoc dl = N->getDebugLoc();
266 // Build a vector of twice the length out of the expanded elements.
267 // For example <3 x i64> -> <6 x i32>.
268 std::vector<SDValue> NewElts;
269 NewElts.reserve(NumElts*2);
271 for (unsigned i = 0; i < NumElts; ++i) {
273 GetExpandedOp(N->getOperand(i), Lo, Hi);
274 if (TLI.isBigEndian())
276 NewElts.push_back(Lo);
277 NewElts.push_back(Hi);
280 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl,
281 MVT::getVectorVT(NewVT, NewElts.size()),
282 &NewElts[0], NewElts.size());
284 // Convert the new vector to the old vector type.
285 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec);
288 SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
290 GetExpandedOp(N->getOperand(0), Lo, Hi);
291 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
294 SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) {
295 // The vector type is legal but the element type needs expansion.
296 MVT VecVT = N->getValueType(0);
297 unsigned NumElts = VecVT.getVectorNumElements();
298 DebugLoc dl = N->getDebugLoc();
300 SDValue Val = N->getOperand(1);
301 MVT OldEVT = Val.getValueType();
302 MVT NewEVT = TLI.getTypeToTransformTo(OldEVT);
304 assert(OldEVT == VecVT.getVectorElementType() &&
305 "Inserted element type doesn't match vector element type!");
307 // Bitconvert to a vector of twice the length with elements of the expanded
308 // type, insert the expanded vector elements, and then convert back.
309 MVT NewVecVT = MVT::getVectorVT(NewEVT, NumElts*2);
310 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT, dl,
311 NewVecVT, N->getOperand(0));
314 GetExpandedOp(Val, Lo, Hi);
315 if (TLI.isBigEndian())
318 SDValue Idx = N->getOperand(2);
319 Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
320 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx);
321 Idx = DAG.getNode(ISD::ADD, dl,
322 Idx.getValueType(), Idx, DAG.getIntPtrConstant(1));
323 NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx);
325 // Convert the new vector to the old vector type.
326 return DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, NewVec);
329 SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) {
330 DebugLoc dl = N->getDebugLoc();
331 MVT VT = N->getValueType(0);
332 unsigned NumElts = VT.getVectorNumElements();
333 SmallVector<SDValue, 16> Ops(NumElts);
334 Ops[0] = N->getOperand(0);
335 SDValue UndefVal = DAG.getNode(ISD::UNDEF, dl, Ops[0].getValueType());
336 for (unsigned i = 1; i < NumElts; ++i)
338 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], NumElts);
341 SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
342 assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
343 assert(OpNo == 1 && "Can only expand the stored value so far");
344 DebugLoc dl = N->getDebugLoc();
346 StoreSDNode *St = cast<StoreSDNode>(N);
347 MVT NVT = TLI.getTypeToTransformTo(St->getValue().getValueType());
348 SDValue Chain = St->getChain();
349 SDValue Ptr = St->getBasePtr();
350 int SVOffset = St->getSrcValueOffset();
351 unsigned Alignment = St->getAlignment();
352 bool isVolatile = St->isVolatile();
354 assert(NVT.isByteSized() && "Expanded type not byte sized!");
355 unsigned IncrementSize = NVT.getSizeInBits() / 8;
358 GetExpandedOp(St->getValue(), Lo, Hi);
360 if (TLI.isBigEndian())
363 Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getSrcValue(), SVOffset,
364 isVolatile, Alignment);
366 Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
367 DAG.getIntPtrConstant(IncrementSize));
368 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!");
369 Hi = DAG.getStore(Chain, dl, Hi, Ptr, St->getSrcValue(),
370 SVOffset + IncrementSize,
371 isVolatile, MinAlign(Alignment, IncrementSize));
373 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
377 //===--------------------------------------------------------------------===//
378 // Generic Result Splitting.
379 //===--------------------------------------------------------------------===//
381 // Be careful to make no assumptions about which of Lo/Hi is stored first in
382 // memory (for vectors it is always Lo first followed by Hi in the following
383 // bytes; for integers and floats it is Lo first if and only if the machine is
386 void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N,
387 SDValue &Lo, SDValue &Hi) {
388 // A MERGE_VALUES node can produce any number of values. We know that the
389 // first illegal one needs to be expanded into Lo/Hi.
392 // The string of legal results gets turned into input operands, which have
394 for (i = 0; isTypeLegal(N->getValueType(i)); ++i)
395 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i)));
397 // The first illegal result must be the one that needs to be expanded.
398 GetSplitOp(N->getOperand(i), Lo, Hi);
400 // Legalize the rest of the results into the input operands whether they are
402 unsigned e = N->getNumValues();
403 for (++i; i != e; ++i)
404 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i)));
407 void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo,
409 SDValue LL, LH, RL, RH;
410 DebugLoc dl = N->getDebugLoc();
411 GetSplitOp(N->getOperand(1), LL, LH);
412 GetSplitOp(N->getOperand(2), RL, RH);
414 SDValue Cond = N->getOperand(0);
415 Lo = DAG.getNode(ISD::SELECT, dl, LL.getValueType(), Cond, LL, RL);
416 Hi = DAG.getNode(ISD::SELECT, dl, LH.getValueType(), Cond, LH, RH);
419 void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo,
421 SDValue LL, LH, RL, RH;
422 DebugLoc dl = N->getDebugLoc();
423 GetSplitOp(N->getOperand(2), LL, LH);
424 GetSplitOp(N->getOperand(3), RL, RH);
426 Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0),
427 N->getOperand(1), LL, RL, N->getOperand(4));
428 Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0),
429 N->getOperand(1), LH, RH, N->getOperand(4));
432 void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) {
434 DebugLoc dl = N->getDebugLoc();
435 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT);
436 Lo = DAG.getNode(ISD::UNDEF, dl, LoVT);
437 Hi = DAG.getNode(ISD::UNDEF, dl, HiVT);