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, SDOperand &Lo,
33 MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
34 SDOperand 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 SDOperand Op = CreateStackStoreLoad(InOp, N->getValueType(0));
78 ExpandRes_NormalLoad(Op.Val, Lo, Hi);
81 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDOperand &Lo,
83 // Return the operands.
84 Lo = N->getOperand(0);
85 Hi = N->getOperand(1);
88 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDOperand &Lo,
90 GetExpandedOp(N->getOperand(0), Lo, Hi);
91 SDOperand Part = cast<ConstantSDNode>(N->getOperand(1))->getValue() ? Hi : Lo;
93 assert(Part.getValueType() == N->getValueType(0) &&
94 "Type twice as big as expanded type not itself expanded!");
95 MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
97 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, NVT, Part,
98 DAG.getConstant(0, TLI.getPointerTy()));
99 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, NVT, Part,
100 DAG.getConstant(1, TLI.getPointerTy()));
103 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDOperand &Lo,
105 SDOperand OldVec = N->getOperand(0);
106 unsigned OldElts = OldVec.getValueType().getVectorNumElements();
108 // Convert to a vector of the expanded element type, for example
109 // <3 x i64> -> <6 x i32>.
110 MVT OldVT = N->getValueType(0);
111 MVT NewVT = TLI.getTypeToTransformTo(OldVT);
113 SDOperand NewVec = DAG.getNode(ISD::BIT_CONVERT,
114 MVT::getVectorVT(NewVT, 2*OldElts),
117 // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
118 SDOperand Idx = N->getOperand(1);
120 // Make sure the type of Idx is big enough to hold the new values.
121 if (Idx.getValueType().bitsLT(TLI.getPointerTy()))
122 Idx = DAG.getNode(ISD::ZERO_EXTEND, TLI.getPointerTy(), Idx);
124 Idx = DAG.getNode(ISD::ADD, Idx.getValueType(), Idx, Idx);
125 Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, NewVT, NewVec, Idx);
127 Idx = DAG.getNode(ISD::ADD, Idx.getValueType(), Idx,
128 DAG.getConstant(1, Idx.getValueType()));
129 Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, NewVT, NewVec, Idx);
131 if (TLI.isBigEndian())
135 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDOperand &Lo,
137 assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
139 LoadSDNode *LD = cast<LoadSDNode>(N);
140 MVT NVT = TLI.getTypeToTransformTo(LD->getValueType(0));
141 SDOperand Chain = LD->getChain();
142 SDOperand Ptr = LD->getBasePtr();
143 int SVOffset = LD->getSrcValueOffset();
144 unsigned Alignment = LD->getAlignment();
145 bool isVolatile = LD->isVolatile();
147 assert(NVT.isByteSized() && "Expanded type not byte sized!");
149 Lo = DAG.getLoad(NVT, Chain, Ptr, LD->getSrcValue(), SVOffset,
150 isVolatile, Alignment);
152 // Increment the pointer to the other half.
153 unsigned IncrementSize = NVT.getSizeInBits() / 8;
154 Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr,
155 DAG.getIntPtrConstant(IncrementSize));
156 Hi = DAG.getLoad(NVT, Chain, Ptr, LD->getSrcValue(), SVOffset+IncrementSize,
157 isVolatile, MinAlign(Alignment, IncrementSize));
159 // Build a factor node to remember that this load is independent of the
161 Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, Lo.getValue(1),
164 // Handle endianness of the load.
165 if (TLI.isBigEndian())
168 // Modified the chain - switch anything that used the old chain to use
170 ReplaceValueWith(SDOperand(N, 1), Chain);
173 //===--------------------------------------------------------------------===//
174 // Generic Operand Expansion.
175 //===--------------------------------------------------------------------===//
177 SDOperand DAGTypeLegalizer::ExpandOp_BIT_CONVERT(SDNode *N) {
178 if (N->getValueType(0).isVector()) {
179 // An illegal expanding type is being converted to a legal vector type.
180 // Make a two element vector out of the expanded parts and convert that
181 // instead, but only if the new vector type is legal (otherwise there
182 // is no point, and it might create expansion loops). For example, on
183 // x86 this turns v1i64 = BIT_CONVERT i64 into v1i64 = BIT_CONVERT v2i32.
184 MVT OVT = N->getOperand(0).getValueType();
185 MVT NVT = MVT::getVectorVT(TLI.getTypeToTransformTo(OVT), 2);
187 if (isTypeLegal(NVT)) {
189 GetExpandedOp(N->getOperand(0), Parts[0], Parts[1]);
191 if (TLI.isBigEndian())
192 std::swap(Parts[0], Parts[1]);
194 SDOperand Vec = DAG.getNode(ISD::BUILD_VECTOR, NVT, Parts, 2);
195 return DAG.getNode(ISD::BIT_CONVERT, N->getValueType(0), Vec);
199 // Otherwise, store to a temporary and load out again as the new type.
200 return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
203 SDOperand DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
204 // The vector type is legal but the element type needs expansion.
205 MVT VecVT = N->getValueType(0);
206 unsigned NumElts = VecVT.getVectorNumElements();
207 MVT OldVT = N->getOperand(0).getValueType();
208 MVT NewVT = TLI.getTypeToTransformTo(OldVT);
210 // Build a vector of twice the length out of the expanded elements.
211 // For example <3 x i64> -> <6 x i32>.
212 std::vector<SDOperand> NewElts;
213 NewElts.reserve(NumElts*2);
215 for (unsigned i = 0; i < NumElts; ++i) {
217 GetExpandedOp(N->getOperand(i), Lo, Hi);
218 if (TLI.isBigEndian())
220 NewElts.push_back(Lo);
221 NewElts.push_back(Hi);
224 SDOperand NewVec = DAG.getNode(ISD::BUILD_VECTOR,
225 MVT::getVectorVT(NewVT, NewElts.size()),
226 &NewElts[0], NewElts.size());
228 // Convert the new vector to the old vector type.
229 return DAG.getNode(ISD::BIT_CONVERT, VecVT, NewVec);
232 SDOperand DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
234 GetExpandedOp(N->getOperand(0), Lo, Hi);
235 return cast<ConstantSDNode>(N->getOperand(1))->getValue() ? Hi : Lo;
238 SDOperand DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
239 assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
240 assert(OpNo == 1 && "Can only expand the stored value so far");
242 StoreSDNode *St = cast<StoreSDNode>(N);
243 MVT NVT = TLI.getTypeToTransformTo(St->getValue().getValueType());
244 SDOperand Chain = St->getChain();
245 SDOperand Ptr = St->getBasePtr();
246 int SVOffset = St->getSrcValueOffset();
247 unsigned Alignment = St->getAlignment();
248 bool isVolatile = St->isVolatile();
250 assert(NVT.isByteSized() && "Expanded type not byte sized!");
251 unsigned IncrementSize = NVT.getSizeInBits() / 8;
254 GetExpandedOp(St->getValue(), Lo, Hi);
256 if (TLI.isBigEndian())
259 Lo = DAG.getStore(Chain, Lo, Ptr, St->getSrcValue(), SVOffset,
260 isVolatile, Alignment);
262 Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr,
263 DAG.getIntPtrConstant(IncrementSize));
264 assert(isTypeLegal(Ptr.getValueType()) && "Pointers must be legal!");
265 Hi = DAG.getStore(Chain, Hi, Ptr, St->getSrcValue(), SVOffset + IncrementSize,
266 isVolatile, MinAlign(Alignment, IncrementSize));
268 return DAG.getNode(ISD::TokenFactor, MVT::Other, Lo, Hi);
272 //===--------------------------------------------------------------------===//
273 // Generic Result Splitting.
274 //===--------------------------------------------------------------------===//
276 // Be careful to make no assumptions about which of Lo/Hi is stored first in
277 // memory (for vectors it is always Lo first followed by Hi in the following
278 // bytes; for integers and floats it is Lo first if and only if the machine is
281 void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N,
282 SDOperand &Lo, SDOperand &Hi) {
283 // A MERGE_VALUES node can produce any number of values. We know that the
284 // first illegal one needs to be expanded into Lo/Hi.
287 // The string of legal results gets turns into the input operands, which have
289 for (i = 0; isTypeLegal(N->getValueType(i)); ++i)
290 ReplaceValueWith(SDOperand(N, i), SDOperand(N->getOperand(i)));
292 // The first illegal result must be the one that needs to be expanded.
293 GetSplitOp(N->getOperand(i), Lo, Hi);
295 // Legalize the rest of the results into the input operands whether they are
297 unsigned e = N->getNumValues();
298 for (++i; i != e; ++i)
299 ReplaceValueWith(SDOperand(N, i), SDOperand(N->getOperand(i)));
302 void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDOperand &Lo,
304 SDOperand LL, LH, RL, RH;
305 GetSplitOp(N->getOperand(1), LL, LH);
306 GetSplitOp(N->getOperand(2), RL, RH);
308 SDOperand Cond = N->getOperand(0);
309 Lo = DAG.getNode(ISD::SELECT, LL.getValueType(), Cond, LL, RL);
310 Hi = DAG.getNode(ISD::SELECT, LH.getValueType(), Cond, LH, RH);
313 void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDOperand &Lo,
315 SDOperand LL, LH, RL, RH;
316 GetSplitOp(N->getOperand(2), LL, LH);
317 GetSplitOp(N->getOperand(3), RL, RH);
319 Lo = DAG.getNode(ISD::SELECT_CC, LL.getValueType(), N->getOperand(0),
320 N->getOperand(1), LL, RL, N->getOperand(4));
321 Hi = DAG.getNode(ISD::SELECT_CC, LH.getValueType(), N->getOperand(0),
322 N->getOperand(1), LH, RH, N->getOperand(4));
325 void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDOperand &Lo, SDOperand &Hi) {
327 GetSplitDestVTs(N->getValueType(0), LoVT, HiVT);
328 Lo = DAG.getNode(ISD::UNDEF, LoVT);
329 Hi = DAG.getNode(ISD::UNDEF, HiVT);