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"
23 //===----------------------------------------------------------------------===//
24 // Generic Result Expansion.
25 //===----------------------------------------------------------------------===//
27 // These routines assume that the Lo/Hi part is stored first in memory on
28 // little/big-endian machines, followed by the Hi/Lo part. This means that
29 // they cannot be used as is on vectors, for which Lo is always stored first.
31 void DAGTypeLegalizer::ExpandRes_BIT_CONVERT(SDNode *N, SDValue &Lo,
33 MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
34 SDValue InOp = N->getOperand(0);
35 MVT InVT = InOp.getValueType();
37 // Handle some special cases efficiently.
38 switch (getTypeAction(InVT)) {
40 assert(false && "Unknown type action!");
45 // Convert the integer operand instead.
46 SplitInteger(GetSoftenedFloat(InOp), Lo, Hi);
47 Lo = DAG.getNode(ISD::BIT_CONVERT, NVT, Lo);
48 Hi = DAG.getNode(ISD::BIT_CONVERT, NVT, Hi);
52 // Convert the expanded pieces of the input.
53 GetExpandedOp(InOp, Lo, Hi);
54 Lo = DAG.getNode(ISD::BIT_CONVERT, NVT, Lo);
55 Hi = DAG.getNode(ISD::BIT_CONVERT, NVT, Hi);
58 // Convert the split parts of the input if it was split in two.
59 GetSplitVector(InOp, Lo, Hi);
60 if (Lo.getValueType() == Hi.getValueType()) {
61 if (TLI.isBigEndian())
63 Lo = DAG.getNode(ISD::BIT_CONVERT, NVT, Lo);
64 Hi = DAG.getNode(ISD::BIT_CONVERT, NVT, Hi);
69 // Convert the element instead.
70 SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi);
71 Lo = DAG.getNode(ISD::BIT_CONVERT, NVT, Lo);
72 Hi = DAG.getNode(ISD::BIT_CONVERT, NVT, Hi);
76 // Lower the bit-convert to a store/load from the stack, then expand the load.
77 SDValue Op = CreateStackStoreLoad(InOp, N->getValueType(0));
78 ExpandRes_NormalLoad(Op.getNode(), Lo, Hi);
81 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
83 // Return the operands.
84 Lo = N->getOperand(0);
85 Hi = N->getOperand(1);
88 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
90 GetExpandedOp(N->getOperand(0), Lo, Hi);
91 SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
94 assert(Part.getValueType() == N->getValueType(0) &&
95 "Type twice as big as expanded type not itself expanded!");
96 MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
98 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, NVT, Part,
99 DAG.getConstant(0, TLI.getPointerTy()));
100 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, NVT, Part,
101 DAG.getConstant(1, TLI.getPointerTy()));
104 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
106 SDValue OldVec = N->getOperand(0);
107 unsigned OldElts = OldVec.getValueType().getVectorNumElements();
109 // Convert to a vector of the expanded element type, for example
110 // <3 x i64> -> <6 x i32>.
111 MVT OldVT = N->getValueType(0);
112 MVT NewVT = TLI.getTypeToTransformTo(OldVT);
114 SDValue NewVec = DAG.getNode(ISD::BIT_CONVERT,
115 MVT::getVectorVT(NewVT, 2*OldElts),
118 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
119 SDValue Idx = N->getOperand(1);
121 // Make sure the type of Idx is big enough to hold the new values.
122 if (Idx.getValueType().bitsLT(TLI.getPointerTy()))
123 Idx = DAG.getNode(ISD::ZERO_EXTEND, TLI.getPointerTy(), Idx);
125 Idx = DAG.getNode(ISD::ADD, Idx.getValueType(), Idx, Idx);
126 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, NewVT, NewVec, Idx);
128 Idx = DAG.getNode(ISD::ADD, Idx.getValueType(), Idx,
129 DAG.getConstant(1, Idx.getValueType()));
130 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, NewVT, NewVec, Idx);
132 if (TLI.isBigEndian())
136 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
138 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
140 LoadSDNode *LD = cast<LoadSDNode>(N);
141 MVT NVT = TLI.getTypeToTransformTo(LD->getValueType(0));
142 SDValue Chain = LD->getChain();
143 SDValue Ptr = LD->getBasePtr();
144 int SVOffset = LD->getSrcValueOffset();
145 unsigned Alignment = LD->getAlignment();
146 bool isVolatile = LD->isVolatile();
148 assert(NVT.isByteSized() && "Expanded type not byte sized!");
150 Lo = DAG.getLoad(NVT, Chain, Ptr, LD->getSrcValue(), SVOffset,
151 isVolatile, Alignment);
153 // Increment the pointer to the other half.
154 unsigned IncrementSize = NVT.getSizeInBits() / 8;
155 Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr,
156 DAG.getIntPtrConstant(IncrementSize));
157 Hi = DAG.getLoad(NVT, Chain, Ptr, LD->getSrcValue(), SVOffset+IncrementSize,
158 isVolatile, MinAlign(Alignment, IncrementSize));
160 // Build a factor node to remember that this load is independent of the
162 Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, Lo.getValue(1),
165 // Handle endianness of the load.
166 if (TLI.isBigEndian())
169 // Modified the chain - switch anything that used the old chain to use
171 ReplaceValueWith(SDValue(N, 1), Chain);
174 void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) {
175 MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
176 SDValue Chain = N->getOperand(0);
177 SDValue Ptr = N->getOperand(1);
179 Lo = DAG.getVAArg(NVT, Chain, Ptr, N->getOperand(2));
180 Hi = DAG.getVAArg(NVT, Lo.getValue(1), Ptr, N->getOperand(2));
182 // Handle endianness of the load.
183 if (TLI.isBigEndian())
186 // Modified the chain - switch anything that used the old chain to use
188 ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
192 //===--------------------------------------------------------------------===//
193 // Generic Operand Expansion.
194 //===--------------------------------------------------------------------===//
196 SDValue DAGTypeLegalizer::ExpandOp_BIT_CONVERT(SDNode *N) {
197 if (N->getValueType(0).isVector()) {
198 // An illegal expanding type is being converted to a legal vector type.
199 // Make a two element vector out of the expanded parts and convert that
200 // instead, but only if the new vector type is legal (otherwise there
201 // is no point, and it might create expansion loops). For example, on
202 // x86 this turns v1i64 = BIT_CONVERT i64 into v1i64 = BIT_CONVERT v2i32.
203 MVT OVT = N->getOperand(0).getValueType();
204 MVT NVT = MVT::getVectorVT(TLI.getTypeToTransformTo(OVT), 2);
206 if (isTypeLegal(NVT)) {
208 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]);
210 if (TLI.isBigEndian())
211 std::swap(Parts[0], Parts[1]);
213 SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, NVT, Parts, 2);
214 return DAG.getNode(ISD::BIT_CONVERT, N->getValueType(0), Vec);
218 // Otherwise, store to a temporary and load out again as the new type.
219 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
222 SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
223 // The vector type is legal but the element type needs expansion.
224 MVT VecVT = N->getValueType(0);
225 unsigned NumElts = VecVT.getVectorNumElements();
226 MVT OldVT = N->getOperand(0).getValueType();
227 MVT NewVT = TLI.getTypeToTransformTo(OldVT);
229 // Build a vector of twice the length out of the expanded elements.
230 // For example <3 x i64> -> <6 x i32>.
231 std::vector<SDValue> NewElts;
232 NewElts.reserve(NumElts*2);
234 for (unsigned i = 0; i < NumElts; ++i) {
236 GetExpandedOp(N->getOperand(i), Lo, Hi);
237 if (TLI.isBigEndian())
239 NewElts.push_back(Lo);
240 NewElts.push_back(Hi);
243 SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR,
244 MVT::getVectorVT(NewVT, NewElts.size()),
245 &NewElts[0], NewElts.size());
247 // Convert the new vector to the old vector type.
248 return DAG.getNode(ISD::BIT_CONVERT, VecVT, NewVec);
251 SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
253 GetExpandedOp(N->getOperand(0), Lo, Hi);
254 return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
257 SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
258 assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
259 assert(OpNo == 1 && "Can only expand the stored value so far");
261 StoreSDNode *St = cast<StoreSDNode>(N);
262 MVT NVT = TLI.getTypeToTransformTo(St->getValue().getValueType());
263 SDValue Chain = St->getChain();
264 SDValue Ptr = St->getBasePtr();
265 int SVOffset = St->getSrcValueOffset();
266 unsigned Alignment = St->getAlignment();
267 bool isVolatile = St->isVolatile();
269 assert(NVT.isByteSized() && "Expanded type not byte sized!");
270 unsigned IncrementSize = NVT.getSizeInBits() / 8;
273 GetExpandedOp(St->getValue(), Lo, Hi);
275 if (TLI.isBigEndian())
278 Lo = DAG.getStore(Chain, Lo, Ptr, St->getSrcValue(), SVOffset,
279 isVolatile, Alignment);
281 Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr,
282 DAG.getIntPtrConstant(IncrementSize));
283 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!");
284 Hi = DAG.getStore(Chain, Hi, Ptr, St->getSrcValue(), SVOffset + IncrementSize,
285 isVolatile, MinAlign(Alignment, IncrementSize));
287 return DAG.getNode(ISD::TokenFactor, MVT::Other, Lo, Hi);
291 //===--------------------------------------------------------------------===//
292 // Generic Result Splitting.
293 //===--------------------------------------------------------------------===//
295 // Be careful to make no assumptions about which of Lo/Hi is stored first in
296 // memory (for vectors it is always Lo first followed by Hi in the following
297 // bytes; for integers and floats it is Lo first if and only if the machine is
300 void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N,
301 SDValue &Lo, SDValue &Hi) {
302 // A MERGE_VALUES node can produce any number of values. We know that the
303 // first illegal one needs to be expanded into Lo/Hi.
306 // The string of legal results gets turned into input operands, which have
308 for (i = 0; isTypeLegal(N->getValueType(i)); ++i)
309 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i)));
311 // The first illegal result must be the one that needs to be expanded.
312 GetSplitOp(N->getOperand(i), Lo, Hi);
314 // Legalize the rest of the results into the input operands whether they are
316 unsigned e = N->getNumValues();
317 for (++i; i != e; ++i)
318 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i)));
321 void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo,
323 SDValue LL, LH, RL, RH;
324 GetSplitOp(N->getOperand(1), LL, LH);
325 GetSplitOp(N->getOperand(2), RL, RH);
327 SDValue Cond = N->getOperand(0);
328 Lo = DAG.getNode(ISD::SELECT, LL.getValueType(), Cond, LL, RL);
329 Hi = DAG.getNode(ISD::SELECT, LH.getValueType(), Cond, LH, RH);
332 void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo,
334 SDValue LL, LH, RL, RH;
335 GetSplitOp(N->getOperand(2), LL, LH);
336 GetSplitOp(N->getOperand(3), RL, RH);
338 Lo = DAG.getNode(ISD::SELECT_CC, LL.getValueType(), N->getOperand(0),
339 N->getOperand(1), LL, RL, N->getOperand(4));
340 Hi = DAG.getNode(ISD::SELECT_CC, LH.getValueType(), N->getOperand(0),
341 N->getOperand(1), LH, RH, N->getOperand(4));
344 void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) {
346 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT);
347 Lo = DAG.getNode(ISD::UNDEF, LoVT);
348 Hi = DAG.getNode(ISD::UNDEF, HiVT);