1 //===-- LegalizeDAG.cpp - Implement SelectionDAG::Legalize ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the SelectionDAG::Legalize method.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/CodeGen/SelectionDAG.h"
15 #include "llvm/CodeGen/MachineConstantPool.h"
16 #include "llvm/CodeGen/MachineFunction.h"
17 #include "llvm/CodeGen/MachineFrameInfo.h"
18 #include "llvm/Target/TargetLowering.h"
19 #include "llvm/Target/TargetData.h"
20 #include "llvm/Target/TargetOptions.h"
21 #include "llvm/Constants.h"
25 //===----------------------------------------------------------------------===//
26 /// SelectionDAGLegalize - This takes an arbitrary SelectionDAG as input and
27 /// hacks on it until the target machine can handle it. This involves
28 /// eliminating value sizes the machine cannot handle (promoting small sizes to
29 /// large sizes or splitting up large values into small values) as well as
30 /// eliminating operations the machine cannot handle.
32 /// This code also does a small amount of optimization and recognition of idioms
33 /// as part of its processing. For example, if a target does not support a
34 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
35 /// will attempt merge setcc and brc instructions into brcc's.
38 class SelectionDAGLegalize {
42 /// LegalizeAction - This enum indicates what action we should take for each
43 /// value type the can occur in the program.
45 Legal, // The target natively supports this value type.
46 Promote, // This should be promoted to the next larger type.
47 Expand, // This integer type should be broken into smaller pieces.
50 /// ValueTypeActions - This is a bitvector that contains two bits for each
51 /// value type, where the two bits correspond to the LegalizeAction enum.
52 /// This can be queried with "getTypeAction(VT)".
53 unsigned ValueTypeActions;
55 /// NeedsAnotherIteration - This is set when we expand a large integer
56 /// operation into smaller integer operations, but the smaller operations are
57 /// not set. This occurs only rarely in practice, for targets that don't have
58 /// 32-bit or larger integer registers.
59 bool NeedsAnotherIteration;
61 /// LegalizedNodes - For nodes that are of legal width, and that have more
62 /// than one use, this map indicates what regularized operand to use. This
63 /// allows us to avoid legalizing the same thing more than once.
64 std::map<SDOperand, SDOperand> LegalizedNodes;
66 /// PromotedNodes - For nodes that are below legal width, and that have more
67 /// than one use, this map indicates what promoted value to use. This allows
68 /// us to avoid promoting the same thing more than once.
69 std::map<SDOperand, SDOperand> PromotedNodes;
71 /// ExpandedNodes - For nodes that need to be expanded, and which have more
72 /// than one use, this map indicates which which operands are the expanded
73 /// version of the input. This allows us to avoid expanding the same node
75 std::map<SDOperand, std::pair<SDOperand, SDOperand> > ExpandedNodes;
77 void AddLegalizedOperand(SDOperand From, SDOperand To) {
78 bool isNew = LegalizedNodes.insert(std::make_pair(From, To)).second;
79 assert(isNew && "Got into the map somehow?");
81 void AddPromotedOperand(SDOperand From, SDOperand To) {
82 bool isNew = PromotedNodes.insert(std::make_pair(From, To)).second;
83 assert(isNew && "Got into the map somehow?");
88 SelectionDAGLegalize(SelectionDAG &DAG);
90 /// Run - While there is still lowering to do, perform a pass over the DAG.
91 /// Most regularization can be done in a single pass, but targets that require
92 /// large values to be split into registers multiple times (e.g. i64 -> 4x
93 /// i16) require iteration for these values (the first iteration will demote
94 /// to i32, the second will demote to i16).
97 NeedsAnotherIteration = false;
99 } while (NeedsAnotherIteration);
102 /// getTypeAction - Return how we should legalize values of this type, either
103 /// it is already legal or we need to expand it into multiple registers of
104 /// smaller integer type, or we need to promote it to a larger type.
105 LegalizeAction getTypeAction(MVT::ValueType VT) const {
106 return (LegalizeAction)((ValueTypeActions >> (2*VT)) & 3);
109 /// isTypeLegal - Return true if this type is legal on this target.
111 bool isTypeLegal(MVT::ValueType VT) const {
112 return getTypeAction(VT) == Legal;
118 SDOperand LegalizeOp(SDOperand O);
119 void ExpandOp(SDOperand O, SDOperand &Lo, SDOperand &Hi);
120 SDOperand PromoteOp(SDOperand O);
122 SDOperand ExpandLibCall(const char *Name, SDNode *Node,
124 SDOperand ExpandIntToFP(bool isSigned, MVT::ValueType DestTy,
126 bool ExpandShift(unsigned Opc, SDOperand Op, SDOperand Amt,
127 SDOperand &Lo, SDOperand &Hi);
128 void ExpandAddSub(bool isAdd, SDOperand Op, SDOperand Amt,
129 SDOperand &Lo, SDOperand &Hi);
131 SDOperand getIntPtrConstant(uint64_t Val) {
132 return DAG.getConstant(Val, TLI.getPointerTy());
138 SelectionDAGLegalize::SelectionDAGLegalize(SelectionDAG &dag)
139 : TLI(dag.getTargetLoweringInfo()), DAG(dag),
140 ValueTypeActions(TLI.getValueTypeActions()) {
141 assert(MVT::LAST_VALUETYPE <= 16 &&
142 "Too many value types for ValueTypeActions to hold!");
145 void SelectionDAGLegalize::LegalizeDAG() {
146 SDOperand OldRoot = DAG.getRoot();
147 SDOperand NewRoot = LegalizeOp(OldRoot);
148 DAG.setRoot(NewRoot);
150 ExpandedNodes.clear();
151 LegalizedNodes.clear();
152 PromotedNodes.clear();
154 // Remove dead nodes now.
155 DAG.RemoveDeadNodes(OldRoot.Val);
158 SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
159 assert(getTypeAction(Op.getValueType()) == Legal &&
160 "Caller should expand or promote operands that are not legal!");
162 // If this operation defines any values that cannot be represented in a
163 // register on this target, make sure to expand or promote them.
164 if (Op.Val->getNumValues() > 1) {
165 for (unsigned i = 0, e = Op.Val->getNumValues(); i != e; ++i)
166 switch (getTypeAction(Op.Val->getValueType(i))) {
167 case Legal: break; // Nothing to do.
170 ExpandOp(Op.getValue(i), T1, T2);
171 assert(LegalizedNodes.count(Op) &&
172 "Expansion didn't add legal operands!");
173 return LegalizedNodes[Op];
176 PromoteOp(Op.getValue(i));
177 assert(LegalizedNodes.count(Op) &&
178 "Expansion didn't add legal operands!");
179 return LegalizedNodes[Op];
183 std::map<SDOperand, SDOperand>::iterator I = LegalizedNodes.find(Op);
184 if (I != LegalizedNodes.end()) return I->second;
186 SDOperand Tmp1, Tmp2, Tmp3;
188 SDOperand Result = Op;
189 SDNode *Node = Op.Val;
191 switch (Node->getOpcode()) {
193 std::cerr << "NODE: "; Node->dump(); std::cerr << "\n";
194 assert(0 && "Do not know how to legalize this operator!");
196 case ISD::EntryToken:
197 case ISD::FrameIndex:
198 case ISD::GlobalAddress:
199 case ISD::ExternalSymbol:
200 case ISD::ConstantPool: // Nothing to do.
201 assert(getTypeAction(Node->getValueType(0)) == Legal &&
202 "This must be legal!");
204 case ISD::CopyFromReg:
205 Tmp1 = LegalizeOp(Node->getOperand(0));
206 if (Tmp1 != Node->getOperand(0))
207 Result = DAG.getCopyFromReg(cast<RegSDNode>(Node)->getReg(),
208 Node->getValueType(0), Tmp1);
210 Result = Op.getValue(0);
212 // Since CopyFromReg produces two values, make sure to remember that we
213 // legalized both of them.
214 AddLegalizedOperand(Op.getValue(0), Result);
215 AddLegalizedOperand(Op.getValue(1), Result.getValue(1));
216 return Result.getValue(Op.ResNo);
217 case ISD::ImplicitDef:
218 Tmp1 = LegalizeOp(Node->getOperand(0));
219 if (Tmp1 != Node->getOperand(0))
220 Result = DAG.getImplicitDef(Tmp1, cast<RegSDNode>(Node)->getReg());
223 MVT::ValueType VT = Op.getValueType();
224 switch (TLI.getOperationAction(ISD::UNDEF, VT)) {
225 default: assert(0 && "This action is not supported yet!");
226 case TargetLowering::Expand:
227 case TargetLowering::Promote:
228 if (MVT::isInteger(VT))
229 Result = DAG.getConstant(0, VT);
230 else if (MVT::isFloatingPoint(VT))
231 Result = DAG.getConstantFP(0, VT);
233 assert(0 && "Unknown value type!");
235 case TargetLowering::Legal:
241 // We know we don't need to expand constants here, constants only have one
242 // value and we check that it is fine above.
244 // FIXME: Maybe we should handle things like targets that don't support full
245 // 32-bit immediates?
247 case ISD::ConstantFP: {
248 // Spill FP immediates to the constant pool if the target cannot directly
249 // codegen them. Targets often have some immediate values that can be
250 // efficiently generated into an FP register without a load. We explicitly
251 // leave these constants as ConstantFP nodes for the target to deal with.
253 ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
255 // Check to see if this FP immediate is already legal.
256 bool isLegal = false;
257 for (TargetLowering::legal_fpimm_iterator I = TLI.legal_fpimm_begin(),
258 E = TLI.legal_fpimm_end(); I != E; ++I)
259 if (CFP->isExactlyValue(*I)) {
265 // Otherwise we need to spill the constant to memory.
266 MachineConstantPool *CP = DAG.getMachineFunction().getConstantPool();
270 // If a FP immediate is precise when represented as a float, we put it
271 // into the constant pool as a float, even if it's is statically typed
273 MVT::ValueType VT = CFP->getValueType(0);
274 bool isDouble = VT == MVT::f64;
275 ConstantFP *LLVMC = ConstantFP::get(isDouble ? Type::DoubleTy :
276 Type::FloatTy, CFP->getValue());
277 if (isDouble && CFP->isExactlyValue((float)CFP->getValue()) &&
278 // Only do this if the target has a native EXTLOAD instruction from
280 TLI.getOperationAction(ISD::EXTLOAD,
281 MVT::f32) == TargetLowering::Legal) {
282 LLVMC = cast<ConstantFP>(ConstantExpr::getCast(LLVMC, Type::FloatTy));
287 SDOperand CPIdx = DAG.getConstantPool(CP->getConstantPoolIndex(LLVMC),
290 Result = DAG.getNode(ISD::EXTLOAD, MVT::f64, DAG.getEntryNode(), CPIdx,
293 Result = DAG.getLoad(VT, DAG.getEntryNode(), CPIdx);
298 case ISD::TokenFactor: {
299 std::vector<SDOperand> Ops;
300 bool Changed = false;
301 for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
302 SDOperand Op = Node->getOperand(i);
303 // Fold single-use TokenFactor nodes into this token factor as we go.
304 if (Op.getOpcode() == ISD::TokenFactor && Op.hasOneUse()) {
306 for (unsigned j = 0, e = Op.getNumOperands(); j != e; ++j)
307 Ops.push_back(LegalizeOp(Op.getOperand(j)));
309 Ops.push_back(LegalizeOp(Op)); // Legalize the operands
310 Changed |= Ops[i] != Op;
314 Result = DAG.getNode(ISD::TokenFactor, MVT::Other, Ops);
318 case ISD::ADJCALLSTACKDOWN:
319 case ISD::ADJCALLSTACKUP:
320 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
321 // There is no need to legalize the size argument (Operand #1)
322 if (Tmp1 != Node->getOperand(0))
323 Result = DAG.getNode(Node->getOpcode(), MVT::Other, Tmp1,
324 Node->getOperand(1));
326 case ISD::DYNAMIC_STACKALLOC:
327 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
328 Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the size.
329 Tmp3 = LegalizeOp(Node->getOperand(2)); // Legalize the alignment.
330 if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) ||
331 Tmp3 != Node->getOperand(2))
332 Result = DAG.getNode(ISD::DYNAMIC_STACKALLOC, Node->getValueType(0),
335 Result = Op.getValue(0);
337 // Since this op produces two values, make sure to remember that we
338 // legalized both of them.
339 AddLegalizedOperand(SDOperand(Node, 0), Result);
340 AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1));
341 return Result.getValue(Op.ResNo);
344 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
345 Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the callee.
347 bool Changed = false;
348 std::vector<SDOperand> Ops;
349 for (unsigned i = 2, e = Node->getNumOperands(); i != e; ++i) {
350 Ops.push_back(LegalizeOp(Node->getOperand(i)));
351 Changed |= Ops.back() != Node->getOperand(i);
354 if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) || Changed) {
355 std::vector<MVT::ValueType> RetTyVTs;
356 RetTyVTs.reserve(Node->getNumValues());
357 for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
358 RetTyVTs.push_back(Node->getValueType(i));
359 Result = SDOperand(DAG.getCall(RetTyVTs, Tmp1, Tmp2, Ops), 0);
361 Result = Result.getValue(0);
363 // Since calls produce multiple values, make sure to remember that we
364 // legalized all of them.
365 for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
366 AddLegalizedOperand(SDOperand(Node, i), Result.getValue(i));
367 return Result.getValue(Op.ResNo);
370 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
371 if (Tmp1 != Node->getOperand(0))
372 Result = DAG.getNode(ISD::BR, MVT::Other, Tmp1, Node->getOperand(1));
376 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
378 switch (getTypeAction(Node->getOperand(1).getValueType())) {
379 case Expand: assert(0 && "It's impossible to expand bools");
381 Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the condition.
384 Tmp2 = PromoteOp(Node->getOperand(1)); // Promote the condition.
387 // Basic block destination (Op#2) is always legal.
388 if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1))
389 Result = DAG.getNode(ISD::BRCOND, MVT::Other, Tmp1, Tmp2,
390 Node->getOperand(2));
394 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
395 Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the pointer.
396 if (Tmp1 != Node->getOperand(0) ||
397 Tmp2 != Node->getOperand(1))
398 Result = DAG.getLoad(Node->getValueType(0), Tmp1, Tmp2);
400 Result = SDOperand(Node, 0);
402 // Since loads produce two values, make sure to remember that we legalized
404 AddLegalizedOperand(SDOperand(Node, 0), Result);
405 AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1));
406 return Result.getValue(Op.ResNo);
411 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
412 Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the pointer.
413 if (Tmp1 != Node->getOperand(0) ||
414 Tmp2 != Node->getOperand(1))
415 Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1, Tmp2,
416 cast<MVTSDNode>(Node)->getExtraValueType());
418 Result = SDOperand(Node, 0);
420 // Since loads produce two values, make sure to remember that we legalized
422 AddLegalizedOperand(SDOperand(Node, 0), Result);
423 AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1));
424 return Result.getValue(Op.ResNo);
426 case ISD::EXTRACT_ELEMENT:
427 // Get both the low and high parts.
428 ExpandOp(Node->getOperand(0), Tmp1, Tmp2);
429 if (cast<ConstantSDNode>(Node->getOperand(1))->getValue())
430 Result = Tmp2; // 1 -> Hi
432 Result = Tmp1; // 0 -> Lo
436 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
438 switch (getTypeAction(Node->getOperand(1).getValueType())) {
440 // Legalize the incoming value (must be legal).
441 Tmp2 = LegalizeOp(Node->getOperand(1));
442 if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1))
443 Result = DAG.getCopyToReg(Tmp1, Tmp2, cast<RegSDNode>(Node)->getReg());
446 Tmp2 = PromoteOp(Node->getOperand(1));
447 Result = DAG.getCopyToReg(Tmp1, Tmp2, cast<RegSDNode>(Node)->getReg());
451 ExpandOp(Node->getOperand(1), Lo, Hi);
452 unsigned Reg = cast<RegSDNode>(Node)->getReg();
453 Lo = DAG.getCopyToReg(Tmp1, Lo, Reg);
454 Hi = DAG.getCopyToReg(Tmp1, Hi, Reg+1);
455 // Note that the copytoreg nodes are independent of each other.
456 Result = DAG.getNode(ISD::TokenFactor, MVT::Other, Lo, Hi);
457 assert(isTypeLegal(Result.getValueType()) &&
458 "Cannot expand multiple times yet (i64 -> i16)");
464 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
465 switch (Node->getNumOperands()) {
467 switch (getTypeAction(Node->getOperand(1).getValueType())) {
469 Tmp2 = LegalizeOp(Node->getOperand(1));
470 if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1))
471 Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1, Tmp2);
475 ExpandOp(Node->getOperand(1), Lo, Hi);
476 Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1, Lo, Hi);
480 Tmp2 = PromoteOp(Node->getOperand(1));
481 Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1, Tmp2);
486 if (Tmp1 != Node->getOperand(0))
487 Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1);
489 default: { // ret <values>
490 std::vector<SDOperand> NewValues;
491 NewValues.push_back(Tmp1);
492 for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i)
493 switch (getTypeAction(Node->getOperand(i).getValueType())) {
495 NewValues.push_back(LegalizeOp(Node->getOperand(i)));
499 ExpandOp(Node->getOperand(i), Lo, Hi);
500 NewValues.push_back(Lo);
501 NewValues.push_back(Hi);
505 assert(0 && "Can't promote multiple return value yet!");
507 Result = DAG.getNode(ISD::RET, MVT::Other, NewValues);
513 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
514 Tmp2 = LegalizeOp(Node->getOperand(2)); // Legalize the pointer.
516 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
517 if (ConstantFPSDNode *CFP =dyn_cast<ConstantFPSDNode>(Node->getOperand(1))){
518 if (CFP->getValueType(0) == MVT::f32) {
523 V.F = CFP->getValue();
524 Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1,
525 DAG.getConstant(V.I, MVT::i32), Tmp2);
527 assert(CFP->getValueType(0) == MVT::f64 && "Unknown FP type!");
532 V.F = CFP->getValue();
533 Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1,
534 DAG.getConstant(V.I, MVT::i64), Tmp2);
539 switch (getTypeAction(Node->getOperand(1).getValueType())) {
541 SDOperand Val = LegalizeOp(Node->getOperand(1));
542 if (Val != Node->getOperand(1) || Tmp1 != Node->getOperand(0) ||
543 Tmp2 != Node->getOperand(2))
544 Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1, Val, Tmp2);
548 // Truncate the value and store the result.
549 Tmp3 = PromoteOp(Node->getOperand(1));
550 Result = DAG.getNode(ISD::TRUNCSTORE, MVT::Other, Tmp1, Tmp3, Tmp2,
551 Node->getOperand(1).getValueType());
556 ExpandOp(Node->getOperand(1), Lo, Hi);
558 if (!TLI.isLittleEndian())
561 Lo = DAG.getNode(ISD::STORE, MVT::Other, Tmp1, Lo, Tmp2);
563 unsigned IncrementSize = MVT::getSizeInBits(Hi.getValueType())/8;
564 Tmp2 = DAG.getNode(ISD::ADD, Tmp2.getValueType(), Tmp2,
565 getIntPtrConstant(IncrementSize));
566 assert(isTypeLegal(Tmp2.getValueType()) &&
567 "Pointers must be legal!");
568 Hi = DAG.getNode(ISD::STORE, MVT::Other, Tmp1, Hi, Tmp2);
569 Result = DAG.getNode(ISD::TokenFactor, MVT::Other, Lo, Hi);
574 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
575 Result = DAG.getNode(ISD::PCMARKER, MVT::Other, Tmp1, Node->getOperand(1));
577 case ISD::TRUNCSTORE:
578 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
579 Tmp3 = LegalizeOp(Node->getOperand(2)); // Legalize the pointer.
581 switch (getTypeAction(Node->getOperand(1).getValueType())) {
583 Tmp2 = LegalizeOp(Node->getOperand(1));
584 if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) ||
585 Tmp3 != Node->getOperand(2))
586 Result = DAG.getNode(ISD::TRUNCSTORE, MVT::Other, Tmp1, Tmp2, Tmp3,
587 cast<MVTSDNode>(Node)->getExtraValueType());
591 assert(0 && "Cannot handle illegal TRUNCSTORE yet!");
595 switch (getTypeAction(Node->getOperand(0).getValueType())) {
596 case Expand: assert(0 && "It's impossible to expand bools");
598 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the condition.
601 Tmp1 = PromoteOp(Node->getOperand(0)); // Promote the condition.
604 Tmp2 = LegalizeOp(Node->getOperand(1)); // TrueVal
605 Tmp3 = LegalizeOp(Node->getOperand(2)); // FalseVal
607 switch (TLI.getOperationAction(Node->getOpcode(), Tmp2.getValueType())) {
608 default: assert(0 && "This action is not supported yet!");
609 case TargetLowering::Legal:
610 if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) ||
611 Tmp3 != Node->getOperand(2))
612 Result = DAG.getNode(ISD::SELECT, Node->getValueType(0),
615 case TargetLowering::Promote: {
617 TLI.getTypeToPromoteTo(ISD::SELECT, Tmp2.getValueType());
618 unsigned ExtOp, TruncOp;
619 if (MVT::isInteger(Tmp2.getValueType())) {
620 ExtOp = ISD::ZERO_EXTEND;
621 TruncOp = ISD::TRUNCATE;
623 ExtOp = ISD::FP_EXTEND;
624 TruncOp = ISD::FP_ROUND;
626 // Promote each of the values to the new type.
627 Tmp2 = DAG.getNode(ExtOp, NVT, Tmp2);
628 Tmp3 = DAG.getNode(ExtOp, NVT, Tmp3);
629 // Perform the larger operation, then round down.
630 Result = DAG.getNode(ISD::SELECT, NVT, Tmp1, Tmp2,Tmp3);
631 Result = DAG.getNode(TruncOp, Node->getValueType(0), Result);
637 switch (getTypeAction(Node->getOperand(0).getValueType())) {
639 Tmp1 = LegalizeOp(Node->getOperand(0)); // LHS
640 Tmp2 = LegalizeOp(Node->getOperand(1)); // RHS
641 if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1))
642 Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(),
643 Node->getValueType(0), Tmp1, Tmp2);
646 Tmp1 = PromoteOp(Node->getOperand(0)); // LHS
647 Tmp2 = PromoteOp(Node->getOperand(1)); // RHS
649 // If this is an FP compare, the operands have already been extended.
650 if (MVT::isInteger(Node->getOperand(0).getValueType())) {
651 MVT::ValueType VT = Node->getOperand(0).getValueType();
652 MVT::ValueType NVT = TLI.getTypeToTransformTo(VT);
654 // Otherwise, we have to insert explicit sign or zero extends. Note
655 // that we could insert sign extends for ALL conditions, but zero extend
656 // is cheaper on many machines (an AND instead of two shifts), so prefer
658 switch (cast<SetCCSDNode>(Node)->getCondition()) {
659 default: assert(0 && "Unknown integer comparison!");
666 // ALL of these operations will work if we either sign or zero extend
667 // the operands (including the unsigned comparisons!). Zero extend is
668 // usually a simpler/cheaper operation, so prefer it.
669 Tmp1 = DAG.getNode(ISD::ZERO_EXTEND_INREG, NVT, Tmp1, VT);
670 Tmp2 = DAG.getNode(ISD::ZERO_EXTEND_INREG, NVT, Tmp2, VT);
676 Tmp1 = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Tmp1, VT);
677 Tmp2 = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Tmp2, VT);
682 Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(),
683 Node->getValueType(0), Tmp1, Tmp2);
686 SDOperand LHSLo, LHSHi, RHSLo, RHSHi;
687 ExpandOp(Node->getOperand(0), LHSLo, LHSHi);
688 ExpandOp(Node->getOperand(1), RHSLo, RHSHi);
689 switch (cast<SetCCSDNode>(Node)->getCondition()) {
692 Tmp1 = DAG.getNode(ISD::XOR, LHSLo.getValueType(), LHSLo, RHSLo);
693 Tmp2 = DAG.getNode(ISD::XOR, LHSLo.getValueType(), LHSHi, RHSHi);
694 Tmp1 = DAG.getNode(ISD::OR, Tmp1.getValueType(), Tmp1, Tmp2);
695 Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(),
696 Node->getValueType(0), Tmp1,
697 DAG.getConstant(0, Tmp1.getValueType()));
700 // FIXME: This generated code sucks.
702 switch (cast<SetCCSDNode>(Node)->getCondition()) {
703 default: assert(0 && "Unknown integer setcc!");
705 case ISD::SETULT: LowCC = ISD::SETULT; break;
707 case ISD::SETUGT: LowCC = ISD::SETUGT; break;
709 case ISD::SETULE: LowCC = ISD::SETULE; break;
711 case ISD::SETUGE: LowCC = ISD::SETUGE; break;
714 // Tmp1 = lo(op1) < lo(op2) // Always unsigned comparison
715 // Tmp2 = hi(op1) < hi(op2) // Signedness depends on operands
716 // dest = hi(op1) == hi(op2) ? Tmp1 : Tmp2;
718 // NOTE: on targets without efficient SELECT of bools, we can always use
719 // this identity: (B1 ? B2 : B3) --> (B1 & B2)|(!B1&B3)
720 Tmp1 = DAG.getSetCC(LowCC, Node->getValueType(0), LHSLo, RHSLo);
721 Tmp2 = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(),
722 Node->getValueType(0), LHSHi, RHSHi);
723 Result = DAG.getSetCC(ISD::SETEQ, Node->getValueType(0), LHSHi, RHSHi);
724 Result = DAG.getNode(ISD::SELECT, Tmp1.getValueType(),
734 Tmp1 = LegalizeOp(Node->getOperand(0)); // Chain
735 Tmp2 = LegalizeOp(Node->getOperand(1)); // Pointer
737 if (Node->getOpcode() == ISD::MEMSET) { // memset = ubyte
738 switch (getTypeAction(Node->getOperand(2).getValueType())) {
739 case Expand: assert(0 && "Cannot expand a byte!");
741 Tmp3 = LegalizeOp(Node->getOperand(2));
744 Tmp3 = PromoteOp(Node->getOperand(2));
748 Tmp3 = LegalizeOp(Node->getOperand(2)); // memcpy/move = pointer,
752 switch (getTypeAction(Node->getOperand(3).getValueType())) {
753 case Expand: assert(0 && "Cannot expand this yet!");
755 Tmp4 = LegalizeOp(Node->getOperand(3));
758 Tmp4 = PromoteOp(Node->getOperand(3));
763 switch (getTypeAction(Node->getOperand(4).getValueType())) { // uint
764 case Expand: assert(0 && "Cannot expand this yet!");
766 Tmp5 = LegalizeOp(Node->getOperand(4));
769 Tmp5 = PromoteOp(Node->getOperand(4));
773 switch (TLI.getOperationAction(Node->getOpcode(), MVT::Other)) {
774 default: assert(0 && "This action not implemented for this operation!");
775 case TargetLowering::Legal:
776 if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) ||
777 Tmp3 != Node->getOperand(2) || Tmp4 != Node->getOperand(3) ||
778 Tmp5 != Node->getOperand(4)) {
779 std::vector<SDOperand> Ops;
780 Ops.push_back(Tmp1); Ops.push_back(Tmp2); Ops.push_back(Tmp3);
781 Ops.push_back(Tmp4); Ops.push_back(Tmp5);
782 Result = DAG.getNode(Node->getOpcode(), MVT::Other, Ops);
785 case TargetLowering::Expand: {
786 // Otherwise, the target does not support this operation. Lower the
787 // operation to an explicit libcall as appropriate.
788 MVT::ValueType IntPtr = TLI.getPointerTy();
789 const Type *IntPtrTy = TLI.getTargetData().getIntPtrType();
790 std::vector<std::pair<SDOperand, const Type*> > Args;
792 const char *FnName = 0;
793 if (Node->getOpcode() == ISD::MEMSET) {
794 Args.push_back(std::make_pair(Tmp2, IntPtrTy));
795 // Extend the ubyte argument to be an int value for the call.
796 Tmp3 = DAG.getNode(ISD::ZERO_EXTEND, MVT::i32, Tmp3);
797 Args.push_back(std::make_pair(Tmp3, Type::IntTy));
798 Args.push_back(std::make_pair(Tmp4, IntPtrTy));
801 } else if (Node->getOpcode() == ISD::MEMCPY ||
802 Node->getOpcode() == ISD::MEMMOVE) {
803 Args.push_back(std::make_pair(Tmp2, IntPtrTy));
804 Args.push_back(std::make_pair(Tmp3, IntPtrTy));
805 Args.push_back(std::make_pair(Tmp4, IntPtrTy));
806 FnName = Node->getOpcode() == ISD::MEMMOVE ? "memmove" : "memcpy";
808 assert(0 && "Unknown op!");
810 std::pair<SDOperand,SDOperand> CallResult =
811 TLI.LowerCallTo(Tmp1, Type::VoidTy, false,
812 DAG.getExternalSymbol(FnName, IntPtr), Args, DAG);
813 Result = LegalizeOp(CallResult.second);
816 case TargetLowering::Custom:
817 std::vector<SDOperand> Ops;
818 Ops.push_back(Tmp1); Ops.push_back(Tmp2); Ops.push_back(Tmp3);
819 Ops.push_back(Tmp4); Ops.push_back(Tmp5);
820 Result = DAG.getNode(Node->getOpcode(), MVT::Other, Ops);
821 Result = TLI.LowerOperation(Result);
822 Result = LegalizeOp(Result);
828 case ISD::SUB_PARTS: {
829 std::vector<SDOperand> Ops;
830 bool Changed = false;
831 for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
832 Ops.push_back(LegalizeOp(Node->getOperand(i)));
833 Changed |= Ops.back() != Node->getOperand(i);
836 Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Ops);
852 Tmp1 = LegalizeOp(Node->getOperand(0)); // LHS
853 Tmp2 = LegalizeOp(Node->getOperand(1)); // RHS
854 if (Tmp1 != Node->getOperand(0) ||
855 Tmp2 != Node->getOperand(1))
856 Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1,Tmp2);
858 case ISD::ZERO_EXTEND:
859 case ISD::SIGN_EXTEND:
863 case ISD::FP_TO_SINT:
864 case ISD::FP_TO_UINT:
865 case ISD::SINT_TO_FP:
866 case ISD::UINT_TO_FP:
867 switch (getTypeAction(Node->getOperand(0).getValueType())) {
869 Tmp1 = LegalizeOp(Node->getOperand(0));
870 if (Tmp1 != Node->getOperand(0))
871 Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1);
874 if (Node->getOpcode() == ISD::SINT_TO_FP ||
875 Node->getOpcode() == ISD::UINT_TO_FP) {
876 Result = ExpandIntToFP(Node->getOpcode() == ISD::SINT_TO_FP,
877 Node->getValueType(0), Node->getOperand(0));
878 Result = LegalizeOp(Result);
881 // In the expand case, we must be dealing with a truncate, because
882 // otherwise the result would be larger than the source.
883 assert(Node->getOpcode() == ISD::TRUNCATE &&
884 "Shouldn't need to expand other operators here!");
885 ExpandOp(Node->getOperand(0), Tmp1, Tmp2);
887 // Since the result is legal, we should just be able to truncate the low
888 // part of the source.
889 Result = DAG.getNode(ISD::TRUNCATE, Node->getValueType(0), Tmp1);
893 switch (Node->getOpcode()) {
894 case ISD::ZERO_EXTEND:
895 Result = PromoteOp(Node->getOperand(0));
896 // NOTE: Any extend would work here...
897 Result = DAG.getNode(ISD::ZERO_EXTEND, Op.getValueType(), Result);
898 Result = DAG.getNode(ISD::ZERO_EXTEND_INREG, Op.getValueType(),
899 Result, Node->getOperand(0).getValueType());
901 case ISD::SIGN_EXTEND:
902 Result = PromoteOp(Node->getOperand(0));
903 // NOTE: Any extend would work here...
904 Result = DAG.getNode(ISD::ZERO_EXTEND, Op.getValueType(), Result);
905 Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, Result.getValueType(),
906 Result, Node->getOperand(0).getValueType());
909 Result = PromoteOp(Node->getOperand(0));
910 Result = DAG.getNode(ISD::TRUNCATE, Op.getValueType(), Result);
913 Result = PromoteOp(Node->getOperand(0));
914 if (Result.getValueType() != Op.getValueType())
915 // Dynamically dead while we have only 2 FP types.
916 Result = DAG.getNode(ISD::FP_EXTEND, Op.getValueType(), Result);
919 case ISD::FP_TO_SINT:
920 case ISD::FP_TO_UINT:
921 Result = PromoteOp(Node->getOperand(0));
922 Result = DAG.getNode(Node->getOpcode(), Op.getValueType(), Result);
924 case ISD::SINT_TO_FP:
925 Result = PromoteOp(Node->getOperand(0));
926 Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, Result.getValueType(),
927 Result, Node->getOperand(0).getValueType());
928 Result = DAG.getNode(ISD::SINT_TO_FP, Op.getValueType(), Result);
930 case ISD::UINT_TO_FP:
931 Result = PromoteOp(Node->getOperand(0));
932 Result = DAG.getNode(ISD::ZERO_EXTEND_INREG, Result.getValueType(),
933 Result, Node->getOperand(0).getValueType());
934 Result = DAG.getNode(ISD::UINT_TO_FP, Op.getValueType(), Result);
939 case ISD::FP_ROUND_INREG:
940 case ISD::SIGN_EXTEND_INREG:
941 case ISD::ZERO_EXTEND_INREG: {
942 Tmp1 = LegalizeOp(Node->getOperand(0));
943 MVT::ValueType ExtraVT = cast<MVTSDNode>(Node)->getExtraValueType();
945 // If this operation is not supported, convert it to a shl/shr or load/store
947 switch (TLI.getOperationAction(Node->getOpcode(), ExtraVT)) {
948 default: assert(0 && "This action not supported for this op yet!");
949 case TargetLowering::Legal:
950 if (Tmp1 != Node->getOperand(0))
951 Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1,
954 case TargetLowering::Expand:
955 // If this is an integer extend and shifts are supported, do that.
956 if (Node->getOpcode() == ISD::ZERO_EXTEND_INREG) {
957 // NOTE: we could fall back on load/store here too for targets without
958 // AND. However, it is doubtful that any exist.
959 // AND out the appropriate bits.
961 DAG.getConstant((1ULL << MVT::getSizeInBits(ExtraVT))-1,
962 Node->getValueType(0));
963 Result = DAG.getNode(ISD::AND, Node->getValueType(0),
964 Node->getOperand(0), Mask);
965 } else if (Node->getOpcode() == ISD::SIGN_EXTEND_INREG) {
966 // NOTE: we could fall back on load/store here too for targets without
967 // SAR. However, it is doubtful that any exist.
968 unsigned BitsDiff = MVT::getSizeInBits(Node->getValueType(0)) -
969 MVT::getSizeInBits(ExtraVT);
970 SDOperand ShiftCst = DAG.getConstant(BitsDiff, TLI.getShiftAmountTy());
971 Result = DAG.getNode(ISD::SHL, Node->getValueType(0),
972 Node->getOperand(0), ShiftCst);
973 Result = DAG.getNode(ISD::SRA, Node->getValueType(0),
975 } else if (Node->getOpcode() == ISD::FP_ROUND_INREG) {
976 // The only way we can lower this is to turn it into a STORETRUNC,
977 // EXTLOAD pair, targetting a temporary location (a stack slot).
979 // NOTE: there is a choice here between constantly creating new stack
980 // slots and always reusing the same one. We currently always create
981 // new ones, as reuse may inhibit scheduling.
982 const Type *Ty = MVT::getTypeForValueType(ExtraVT);
983 unsigned TySize = (unsigned)TLI.getTargetData().getTypeSize(Ty);
984 unsigned Align = TLI.getTargetData().getTypeAlignment(Ty);
985 MachineFunction &MF = DAG.getMachineFunction();
987 MF.getFrameInfo()->CreateStackObject((unsigned)TySize, Align);
988 SDOperand StackSlot = DAG.getFrameIndex(SSFI, TLI.getPointerTy());
989 Result = DAG.getNode(ISD::TRUNCSTORE, MVT::Other, DAG.getEntryNode(),
990 Node->getOperand(0), StackSlot, ExtraVT);
991 Result = DAG.getNode(ISD::EXTLOAD, Node->getValueType(0),
992 Result, StackSlot, ExtraVT);
994 assert(0 && "Unknown op");
996 Result = LegalizeOp(Result);
1003 if (!Op.Val->hasOneUse())
1004 AddLegalizedOperand(Op, Result);
1009 /// PromoteOp - Given an operation that produces a value in an invalid type,
1010 /// promote it to compute the value into a larger type. The produced value will
1011 /// have the correct bits for the low portion of the register, but no guarantee
1012 /// is made about the top bits: it may be zero, sign-extended, or garbage.
1013 SDOperand SelectionDAGLegalize::PromoteOp(SDOperand Op) {
1014 MVT::ValueType VT = Op.getValueType();
1015 MVT::ValueType NVT = TLI.getTypeToTransformTo(VT);
1016 assert(getTypeAction(VT) == Promote &&
1017 "Caller should expand or legalize operands that are not promotable!");
1018 assert(NVT > VT && MVT::isInteger(NVT) == MVT::isInteger(VT) &&
1019 "Cannot promote to smaller type!");
1021 std::map<SDOperand, SDOperand>::iterator I = PromotedNodes.find(Op);
1022 if (I != PromotedNodes.end()) return I->second;
1024 SDOperand Tmp1, Tmp2, Tmp3;
1027 SDNode *Node = Op.Val;
1029 // Promotion needs an optimization step to clean up after it, and is not
1030 // careful to avoid operations the target does not support. Make sure that
1031 // all generated operations are legalized in the next iteration.
1032 NeedsAnotherIteration = true;
1034 switch (Node->getOpcode()) {
1036 std::cerr << "NODE: "; Node->dump(); std::cerr << "\n";
1037 assert(0 && "Do not know how to promote this operator!");
1040 Result = DAG.getNode(ISD::UNDEF, NVT);
1043 Result = DAG.getNode(ISD::ZERO_EXTEND, NVT, Op);
1044 assert(isa<ConstantSDNode>(Result) && "Didn't constant fold zext?");
1046 case ISD::ConstantFP:
1047 Result = DAG.getNode(ISD::FP_EXTEND, NVT, Op);
1048 assert(isa<ConstantFPSDNode>(Result) && "Didn't constant fold fp_extend?");
1050 case ISD::CopyFromReg:
1051 Result = DAG.getCopyFromReg(cast<RegSDNode>(Node)->getReg(), NVT,
1052 Node->getOperand(0));
1053 // Remember that we legalized the chain.
1054 AddLegalizedOperand(Op.getValue(1), Result.getValue(1));
1058 assert(getTypeAction(TLI.getSetCCResultTy()) == Legal &&
1059 "SetCC type is not legal??");
1060 Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(),
1061 TLI.getSetCCResultTy(), Node->getOperand(0),
1062 Node->getOperand(1));
1063 Result = LegalizeOp(Result);
1067 switch (getTypeAction(Node->getOperand(0).getValueType())) {
1069 Result = LegalizeOp(Node->getOperand(0));
1070 assert(Result.getValueType() >= NVT &&
1071 "This truncation doesn't make sense!");
1072 if (Result.getValueType() > NVT) // Truncate to NVT instead of VT
1073 Result = DAG.getNode(ISD::TRUNCATE, NVT, Result);
1076 // The truncation is not required, because we don't guarantee anything
1077 // about high bits anyway.
1078 Result = PromoteOp(Node->getOperand(0));
1081 assert(0 && "Cannot handle expand yet");
1084 case ISD::SIGN_EXTEND:
1085 case ISD::ZERO_EXTEND:
1086 switch (getTypeAction(Node->getOperand(0).getValueType())) {
1087 case Expand: assert(0 && "BUG: Smaller reg should have been promoted!");
1089 // Input is legal? Just do extend all the way to the larger type.
1090 Result = LegalizeOp(Node->getOperand(0));
1091 Result = DAG.getNode(Node->getOpcode(), NVT, Result);
1094 // Promote the reg if it's smaller.
1095 Result = PromoteOp(Node->getOperand(0));
1096 // The high bits are not guaranteed to be anything. Insert an extend.
1097 if (Node->getOpcode() == ISD::SIGN_EXTEND)
1098 Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Result,
1099 Node->getOperand(0).getValueType());
1101 Result = DAG.getNode(ISD::ZERO_EXTEND_INREG, NVT, Result,
1102 Node->getOperand(0).getValueType());
1107 case ISD::FP_EXTEND:
1108 assert(0 && "Case not implemented. Dynamically dead with 2 FP types!");
1110 switch (getTypeAction(Node->getOperand(0).getValueType())) {
1111 case Expand: assert(0 && "BUG: Cannot expand FP regs!");
1112 case Promote: assert(0 && "Unreachable with 2 FP types!");
1114 // Input is legal? Do an FP_ROUND_INREG.
1115 Result = LegalizeOp(Node->getOperand(0));
1116 Result = DAG.getNode(ISD::FP_ROUND_INREG, NVT, Result, VT);
1121 case ISD::SINT_TO_FP:
1122 case ISD::UINT_TO_FP:
1123 switch (getTypeAction(Node->getOperand(0).getValueType())) {
1125 Result = LegalizeOp(Node->getOperand(0));
1126 // No extra round required here.
1127 Result = DAG.getNode(Node->getOpcode(), NVT, Result);
1131 Result = PromoteOp(Node->getOperand(0));
1132 if (Node->getOpcode() == ISD::SINT_TO_FP)
1133 Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, Result.getValueType(),
1134 Result, Node->getOperand(0).getValueType());
1136 Result = DAG.getNode(ISD::ZERO_EXTEND_INREG, Result.getValueType(),
1137 Result, Node->getOperand(0).getValueType());
1138 // No extra round required here.
1139 Result = DAG.getNode(Node->getOpcode(), NVT, Result);
1142 Result = ExpandIntToFP(Node->getOpcode() == ISD::SINT_TO_FP, NVT,
1143 Node->getOperand(0));
1144 Result = LegalizeOp(Result);
1146 // Round if we cannot tolerate excess precision.
1147 if (NoExcessFPPrecision)
1148 Result = DAG.getNode(ISD::FP_ROUND_INREG, NVT, Result, VT);
1153 case ISD::FP_TO_SINT:
1154 case ISD::FP_TO_UINT:
1155 switch (getTypeAction(Node->getOperand(0).getValueType())) {
1157 Tmp1 = LegalizeOp(Node->getOperand(0));
1160 // The input result is prerounded, so we don't have to do anything
1162 Tmp1 = PromoteOp(Node->getOperand(0));
1165 assert(0 && "not implemented");
1167 Result = DAG.getNode(Node->getOpcode(), NVT, Tmp1);
1176 // The input may have strange things in the top bits of the registers, but
1177 // these operations don't care. They may have wierd bits going out, but
1178 // that too is okay if they are integer operations.
1179 Tmp1 = PromoteOp(Node->getOperand(0));
1180 Tmp2 = PromoteOp(Node->getOperand(1));
1181 assert(Tmp1.getValueType() == NVT && Tmp2.getValueType() == NVT);
1182 Result = DAG.getNode(Node->getOpcode(), NVT, Tmp1, Tmp2);
1184 // However, if this is a floating point operation, they will give excess
1185 // precision that we may not be able to tolerate. If we DO allow excess
1186 // precision, just leave it, otherwise excise it.
1187 // FIXME: Why would we need to round FP ops more than integer ones?
1188 // Is Round(Add(Add(A,B),C)) != Round(Add(Round(Add(A,B)), C))
1189 if (MVT::isFloatingPoint(NVT) && NoExcessFPPrecision)
1190 Result = DAG.getNode(ISD::FP_ROUND_INREG, NVT, Result, VT);
1195 // These operators require that their input be sign extended.
1196 Tmp1 = PromoteOp(Node->getOperand(0));
1197 Tmp2 = PromoteOp(Node->getOperand(1));
1198 if (MVT::isInteger(NVT)) {
1199 Tmp1 = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Tmp1, VT);
1200 Tmp2 = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Tmp2, VT);
1202 Result = DAG.getNode(Node->getOpcode(), NVT, Tmp1, Tmp2);
1204 // Perform FP_ROUND: this is probably overly pessimistic.
1205 if (MVT::isFloatingPoint(NVT) && NoExcessFPPrecision)
1206 Result = DAG.getNode(ISD::FP_ROUND_INREG, NVT, Result, VT);
1211 // These operators require that their input be zero extended.
1212 Tmp1 = PromoteOp(Node->getOperand(0));
1213 Tmp2 = PromoteOp(Node->getOperand(1));
1214 assert(MVT::isInteger(NVT) && "Operators don't apply to FP!");
1215 Tmp1 = DAG.getNode(ISD::ZERO_EXTEND_INREG, NVT, Tmp1, VT);
1216 Tmp2 = DAG.getNode(ISD::ZERO_EXTEND_INREG, NVT, Tmp2, VT);
1217 Result = DAG.getNode(Node->getOpcode(), NVT, Tmp1, Tmp2);
1221 Tmp1 = PromoteOp(Node->getOperand(0));
1222 Tmp2 = LegalizeOp(Node->getOperand(1));
1223 Result = DAG.getNode(ISD::SHL, NVT, Tmp1, Tmp2);
1226 // The input value must be properly sign extended.
1227 Tmp1 = PromoteOp(Node->getOperand(0));
1228 Tmp1 = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Tmp1, VT);
1229 Tmp2 = LegalizeOp(Node->getOperand(1));
1230 Result = DAG.getNode(ISD::SRA, NVT, Tmp1, Tmp2);
1233 // The input value must be properly zero extended.
1234 Tmp1 = PromoteOp(Node->getOperand(0));
1235 Tmp1 = DAG.getNode(ISD::ZERO_EXTEND_INREG, NVT, Tmp1, VT);
1236 Tmp2 = LegalizeOp(Node->getOperand(1));
1237 Result = DAG.getNode(ISD::SRL, NVT, Tmp1, Tmp2);
1240 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
1241 Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the pointer.
1242 Result = DAG.getNode(ISD::EXTLOAD, NVT, Tmp1, Tmp2, VT);
1244 // Remember that we legalized the chain.
1245 AddLegalizedOperand(Op.getValue(1), Result.getValue(1));
1248 switch (getTypeAction(Node->getOperand(0).getValueType())) {
1249 case Expand: assert(0 && "It's impossible to expand bools");
1251 Tmp1 = LegalizeOp(Node->getOperand(0));// Legalize the condition.
1254 Tmp1 = PromoteOp(Node->getOperand(0)); // Promote the condition.
1257 Tmp2 = PromoteOp(Node->getOperand(1)); // Legalize the op0
1258 Tmp3 = PromoteOp(Node->getOperand(2)); // Legalize the op1
1259 Result = DAG.getNode(ISD::SELECT, NVT, Tmp1, Tmp2, Tmp3);
1262 Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
1263 Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the callee.
1265 std::vector<SDOperand> Ops;
1266 for (unsigned i = 2, e = Node->getNumOperands(); i != e; ++i)
1267 Ops.push_back(LegalizeOp(Node->getOperand(i)));
1269 assert(Node->getNumValues() == 2 && Op.ResNo == 0 &&
1270 "Can only promote single result calls");
1271 std::vector<MVT::ValueType> RetTyVTs;
1272 RetTyVTs.reserve(2);
1273 RetTyVTs.push_back(NVT);
1274 RetTyVTs.push_back(MVT::Other);
1275 SDNode *NC = DAG.getCall(RetTyVTs, Tmp1, Tmp2, Ops);
1276 Result = SDOperand(NC, 0);
1278 // Insert the new chain mapping.
1279 AddLegalizedOperand(Op.getValue(1), Result.getValue(1));
1284 assert(Result.Val && "Didn't set a result!");
1285 AddPromotedOperand(Op, Result);
1289 /// ExpandAddSub - Find a clever way to expand this add operation into
1291 void SelectionDAGLegalize::ExpandAddSub(bool isAdd, SDOperand LHS,SDOperand RHS,
1292 SDOperand &Lo, SDOperand &Hi) {
1293 // Expand the subcomponents.
1294 SDOperand LHSL, LHSH, RHSL, RHSH;
1295 ExpandOp(LHS, LHSL, LHSH);
1296 ExpandOp(RHS, RHSL, RHSH);
1298 // Convert this add to the appropriate ADDC pair. The low part has no carry
1300 unsigned Opc = isAdd ? ISD::ADD_PARTS : ISD::SUB_PARTS;
1301 std::vector<SDOperand> Ops;
1302 Ops.push_back(LHSL);
1303 Ops.push_back(LHSH);
1304 Ops.push_back(RHSL);
1305 Ops.push_back(RHSH);
1306 Lo = DAG.getNode(Opc, LHSL.getValueType(), Ops);
1307 Hi = Lo.getValue(1);
1310 /// ExpandShift - Try to find a clever way to expand this shift operation out to
1311 /// smaller elements. If we can't find a way that is more efficient than a
1312 /// libcall on this target, return false. Otherwise, return true with the
1313 /// low-parts expanded into Lo and Hi.
1314 bool SelectionDAGLegalize::ExpandShift(unsigned Opc, SDOperand Op,SDOperand Amt,
1315 SDOperand &Lo, SDOperand &Hi) {
1316 assert((Opc == ISD::SHL || Opc == ISD::SRA || Opc == ISD::SRL) &&
1317 "This is not a shift!");
1318 MVT::ValueType NVT = TLI.getTypeToTransformTo(Op.getValueType());
1320 // If we have an efficient select operation (or if the selects will all fold
1321 // away), lower to some complex code, otherwise just emit the libcall.
1322 if (TLI.getOperationAction(ISD::SELECT, NVT) != TargetLowering::Legal &&
1323 !isa<ConstantSDNode>(Amt))
1327 ExpandOp(Op, InL, InH);
1328 SDOperand ShAmt = LegalizeOp(Amt);
1329 MVT::ValueType ShTy = ShAmt.getValueType();
1331 unsigned NVTBits = MVT::getSizeInBits(NVT);
1332 SDOperand NAmt = DAG.getNode(ISD::SUB, ShTy, // NAmt = 32-ShAmt
1333 DAG.getConstant(NVTBits, ShTy), ShAmt);
1335 // Compare the unmasked shift amount against 32.
1336 SDOperand Cond = DAG.getSetCC(ISD::SETGE, TLI.getSetCCResultTy(), ShAmt,
1337 DAG.getConstant(NVTBits, ShTy));
1339 if (TLI.getShiftAmountFlavor() != TargetLowering::Mask) {
1340 ShAmt = DAG.getNode(ISD::AND, ShTy, ShAmt, // ShAmt &= 31
1341 DAG.getConstant(NVTBits-1, ShTy));
1342 NAmt = DAG.getNode(ISD::AND, ShTy, NAmt, // NAmt &= 31
1343 DAG.getConstant(NVTBits-1, ShTy));
1346 if (Opc == ISD::SHL) {
1347 SDOperand T1 = DAG.getNode(ISD::OR, NVT,// T1 = (Hi << Amt) | (Lo >> NAmt)
1348 DAG.getNode(ISD::SHL, NVT, InH, ShAmt),
1349 DAG.getNode(ISD::SRL, NVT, InL, NAmt));
1350 SDOperand T2 = DAG.getNode(ISD::SHL, NVT, InL, ShAmt); // T2 = Lo << Amt&31
1352 Hi = DAG.getNode(ISD::SELECT, NVT, Cond, T2, T1);
1353 Lo = DAG.getNode(ISD::SELECT, NVT, Cond, DAG.getConstant(0, NVT), T2);
1355 SDOperand HiLoPart = DAG.getNode(ISD::SELECT, NVT,
1356 DAG.getSetCC(ISD::SETEQ,
1357 TLI.getSetCCResultTy(), NAmt,
1358 DAG.getConstant(32, ShTy)),
1359 DAG.getConstant(0, NVT),
1360 DAG.getNode(ISD::SHL, NVT, InH, NAmt));
1361 SDOperand T1 = DAG.getNode(ISD::OR, NVT,// T1 = (Hi << NAmt) | (Lo >> Amt)
1363 DAG.getNode(ISD::SRL, NVT, InL, ShAmt));
1364 SDOperand T2 = DAG.getNode(Opc, NVT, InH, ShAmt); // T2 = InH >> ShAmt&31
1367 if (Opc == ISD::SRA)
1368 HiPart = DAG.getNode(ISD::SRA, NVT, InH,
1369 DAG.getConstant(NVTBits-1, ShTy));
1371 HiPart = DAG.getConstant(0, NVT);
1372 Lo = DAG.getNode(ISD::SELECT, NVT, Cond, T2, T1);
1373 Hi = DAG.getNode(ISD::SELECT, NVT, Cond, HiPart, T2);
1378 /// FindLatestAdjCallStackDown - Scan up the dag to find the latest (highest
1379 /// NodeDepth) node that is an AdjCallStackDown operation and occurs later than
1381 static void FindLatestAdjCallStackDown(SDNode *Node, SDNode *&Found) {
1382 if (Node->getNodeDepth() <= Found->getNodeDepth()) return;
1384 // If we found an ADJCALLSTACKDOWN, we already know this node occurs later
1385 // than the Found node. Just remember this node and return.
1386 if (Node->getOpcode() == ISD::ADJCALLSTACKDOWN) {
1391 // Otherwise, scan the operands of Node to see if any of them is a call.
1392 assert(Node->getNumOperands() != 0 &&
1393 "All leaves should have depth equal to the entry node!");
1394 for (unsigned i = 0, e = Node->getNumOperands()-1; i != e; ++i)
1395 FindLatestAdjCallStackDown(Node->getOperand(i).Val, Found);
1397 // Tail recurse for the last iteration.
1398 FindLatestAdjCallStackDown(Node->getOperand(Node->getNumOperands()-1).Val,
1403 /// FindEarliestAdjCallStackUp - Scan down the dag to find the earliest (lowest
1404 /// NodeDepth) node that is an AdjCallStackUp operation and occurs more recent
1406 static void FindEarliestAdjCallStackUp(SDNode *Node, SDNode *&Found) {
1407 if (Found && Node->getNodeDepth() >= Found->getNodeDepth()) return;
1409 // If we found an ADJCALLSTACKUP, we already know this node occurs earlier
1410 // than the Found node. Just remember this node and return.
1411 if (Node->getOpcode() == ISD::ADJCALLSTACKUP) {
1416 // Otherwise, scan the operands of Node to see if any of them is a call.
1417 SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
1418 if (UI == E) return;
1419 for (--E; UI != E; ++UI)
1420 FindEarliestAdjCallStackUp(*UI, Found);
1422 // Tail recurse for the last iteration.
1423 FindEarliestAdjCallStackUp(*UI, Found);
1426 /// FindAdjCallStackUp - Given a chained node that is part of a call sequence,
1427 /// find the ADJCALLSTACKUP node that terminates the call sequence.
1428 static SDNode *FindAdjCallStackUp(SDNode *Node) {
1429 if (Node->getOpcode() == ISD::ADJCALLSTACKUP)
1431 if (Node->use_empty())
1432 return 0; // No adjcallstackup
1434 if (Node->hasOneUse()) // Simple case, only has one user to check.
1435 return FindAdjCallStackUp(*Node->use_begin());
1437 SDOperand TheChain(Node, Node->getNumValues()-1);
1438 assert(TheChain.getValueType() == MVT::Other && "Is not a token chain!");
1440 for (SDNode::use_iterator UI = Node->use_begin(),
1441 E = Node->use_end(); ; ++UI) {
1442 assert(UI != E && "Didn't find a user of the tokchain, no ADJCALLSTACKUP!");
1444 // Make sure to only follow users of our token chain.
1446 for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i)
1447 if (User->getOperand(i) == TheChain)
1448 return FindAdjCallStackUp(User);
1450 assert(0 && "Unreachable");
1454 /// FindInputOutputChains - If we are replacing an operation with a call we need
1455 /// to find the call that occurs before and the call that occurs after it to
1456 /// properly serialize the calls in the block.
1457 static SDOperand FindInputOutputChains(SDNode *OpNode, SDNode *&OutChain,
1459 SDNode *LatestAdjCallStackDown = Entry.Val;
1460 FindLatestAdjCallStackDown(OpNode, LatestAdjCallStackDown);
1461 //std::cerr << "Found node: "; LatestAdjCallStackDown->dump(); std::cerr <<"\n";
1463 SDNode *LatestAdjCallStackUp = FindAdjCallStackUp(LatestAdjCallStackDown);
1466 SDNode *EarliestAdjCallStackUp = 0;
1467 FindEarliestAdjCallStackUp(OpNode, EarliestAdjCallStackUp);
1469 if (EarliestAdjCallStackUp) {
1470 //std::cerr << "Found node: ";
1471 //EarliestAdjCallStackUp->dump(); std::cerr <<"\n";
1474 return SDOperand(LatestAdjCallStackUp, 0);
1479 // ExpandLibCall - Expand a node into a call to a libcall. If the result value
1480 // does not fit into a register, return the lo part and set the hi part to the
1481 // by-reg argument. If it does fit into a single register, return the result
1482 // and leave the Hi part unset.
1483 SDOperand SelectionDAGLegalize::ExpandLibCall(const char *Name, SDNode *Node,
1486 SDOperand InChain = FindInputOutputChains(Node, OutChain,
1487 DAG.getEntryNode());
1488 if (InChain.Val == 0)
1489 InChain = DAG.getEntryNode();
1491 TargetLowering::ArgListTy Args;
1492 for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1493 MVT::ValueType ArgVT = Node->getOperand(i).getValueType();
1494 const Type *ArgTy = MVT::getTypeForValueType(ArgVT);
1495 Args.push_back(std::make_pair(Node->getOperand(i), ArgTy));
1497 SDOperand Callee = DAG.getExternalSymbol(Name, TLI.getPointerTy());
1499 // We don't care about token chains for libcalls. We just use the entry
1500 // node as our input and ignore the output chain. This allows us to place
1501 // calls wherever we need them to satisfy data dependences.
1502 const Type *RetTy = MVT::getTypeForValueType(Node->getValueType(0));
1503 SDOperand Result = TLI.LowerCallTo(InChain, RetTy, false, Callee,
1505 switch (getTypeAction(Result.getValueType())) {
1506 default: assert(0 && "Unknown thing");
1510 assert(0 && "Cannot promote this yet!");
1513 ExpandOp(Result, Lo, Hi);
1519 /// ExpandIntToFP - Expand a [US]INT_TO_FP operation, assuming that the
1520 /// destination type is legal.
1521 SDOperand SelectionDAGLegalize::
1522 ExpandIntToFP(bool isSigned, MVT::ValueType DestTy, SDOperand Source) {
1523 assert(getTypeAction(DestTy) == Legal && "Destination type is not legal!");
1524 assert(getTypeAction(Source.getValueType()) == Expand &&
1525 "This is not an expansion!");
1526 assert(Source.getValueType() == MVT::i64 && "Only handle expand from i64!");
1529 SDOperand InChain = FindInputOutputChains(Source.Val, OutChain,
1530 DAG.getEntryNode());
1532 const char *FnName = 0;
1534 if (DestTy == MVT::f32)
1535 FnName = "__floatdisf";
1537 assert(DestTy == MVT::f64 && "Unknown fp value type!");
1538 FnName = "__floatdidf";
1541 // If this is unsigned, and not supported, first perform the conversion to
1542 // signed, then adjust the result if the sign bit is set.
1543 SDOperand SignedConv = ExpandIntToFP(false, DestTy, Source);
1545 assert(0 && "Unsigned casts not supported yet!");
1547 SDOperand Callee = DAG.getExternalSymbol(FnName, TLI.getPointerTy());
1549 TargetLowering::ArgListTy Args;
1550 const Type *ArgTy = MVT::getTypeForValueType(Source.getValueType());
1551 Args.push_back(std::make_pair(Source, ArgTy));
1553 // We don't care about token chains for libcalls. We just use the entry
1554 // node as our input and ignore the output chain. This allows us to place
1555 // calls wherever we need them to satisfy data dependences.
1556 const Type *RetTy = MVT::getTypeForValueType(DestTy);
1557 return TLI.LowerCallTo(InChain, RetTy, false, Callee, Args, DAG).first;
1563 /// ExpandOp - Expand the specified SDOperand into its two component pieces
1564 /// Lo&Hi. Note that the Op MUST be an expanded type. As a result of this, the
1565 /// LegalizeNodes map is filled in for any results that are not expanded, the
1566 /// ExpandedNodes map is filled in for any results that are expanded, and the
1567 /// Lo/Hi values are returned.
1568 void SelectionDAGLegalize::ExpandOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi){
1569 MVT::ValueType VT = Op.getValueType();
1570 MVT::ValueType NVT = TLI.getTypeToTransformTo(VT);
1571 SDNode *Node = Op.Val;
1572 assert(getTypeAction(VT) == Expand && "Not an expanded type!");
1573 assert(MVT::isInteger(VT) && "Cannot expand FP values!");
1574 assert(MVT::isInteger(NVT) && NVT < VT &&
1575 "Cannot expand to FP value or to larger int value!");
1577 // If there is more than one use of this, see if we already expanded it.
1578 // There is no use remembering values that only have a single use, as the map
1579 // entries will never be reused.
1580 if (!Node->hasOneUse()) {
1581 std::map<SDOperand, std::pair<SDOperand, SDOperand> >::iterator I
1582 = ExpandedNodes.find(Op);
1583 if (I != ExpandedNodes.end()) {
1584 Lo = I->second.first;
1585 Hi = I->second.second;
1590 // Expanding to multiple registers needs to perform an optimization step, and
1591 // is not careful to avoid operations the target does not support. Make sure
1592 // that all generated operations are legalized in the next iteration.
1593 NeedsAnotherIteration = true;
1595 switch (Node->getOpcode()) {
1597 std::cerr << "NODE: "; Node->dump(); std::cerr << "\n";
1598 assert(0 && "Do not know how to expand this operator!");
1601 Lo = DAG.getNode(ISD::UNDEF, NVT);
1602 Hi = DAG.getNode(ISD::UNDEF, NVT);
1604 case ISD::Constant: {
1605 uint64_t Cst = cast<ConstantSDNode>(Node)->getValue();
1606 Lo = DAG.getConstant(Cst, NVT);
1607 Hi = DAG.getConstant(Cst >> MVT::getSizeInBits(NVT), NVT);
1611 case ISD::CopyFromReg: {
1612 unsigned Reg = cast<RegSDNode>(Node)->getReg();
1613 // Aggregate register values are always in consequtive pairs.
1614 Lo = DAG.getCopyFromReg(Reg, NVT, Node->getOperand(0));
1615 Hi = DAG.getCopyFromReg(Reg+1, NVT, Lo.getValue(1));
1617 // Remember that we legalized the chain.
1618 AddLegalizedOperand(Op.getValue(1), Hi.getValue(1));
1620 assert(isTypeLegal(NVT) && "Cannot expand this multiple times yet!");
1624 case ISD::BUILD_PAIR:
1625 // Legalize both operands. FIXME: in the future we should handle the case
1626 // where the two elements are not legal.
1627 assert(isTypeLegal(NVT) && "Cannot expand this multiple times yet!");
1628 Lo = LegalizeOp(Node->getOperand(0));
1629 Hi = LegalizeOp(Node->getOperand(1));
1633 SDOperand Ch = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
1634 SDOperand Ptr = LegalizeOp(Node->getOperand(1)); // Legalize the pointer.
1635 Lo = DAG.getLoad(NVT, Ch, Ptr);
1637 // Increment the pointer to the other half.
1638 unsigned IncrementSize = MVT::getSizeInBits(Lo.getValueType())/8;
1639 Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr,
1640 getIntPtrConstant(IncrementSize));
1641 Hi = DAG.getLoad(NVT, Ch, Ptr);
1643 // Build a factor node to remember that this load is independent of the
1645 SDOperand TF = DAG.getNode(ISD::TokenFactor, MVT::Other, Lo.getValue(1),
1648 // Remember that we legalized the chain.
1649 AddLegalizedOperand(Op.getValue(1), TF);
1650 if (!TLI.isLittleEndian())
1655 SDOperand Chain = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
1656 SDOperand Callee = LegalizeOp(Node->getOperand(1)); // Legalize the callee.
1658 bool Changed = false;
1659 std::vector<SDOperand> Ops;
1660 for (unsigned i = 2, e = Node->getNumOperands(); i != e; ++i) {
1661 Ops.push_back(LegalizeOp(Node->getOperand(i)));
1662 Changed |= Ops.back() != Node->getOperand(i);
1665 assert(Node->getNumValues() == 2 && Op.ResNo == 0 &&
1666 "Can only expand a call once so far, not i64 -> i16!");
1668 std::vector<MVT::ValueType> RetTyVTs;
1669 RetTyVTs.reserve(3);
1670 RetTyVTs.push_back(NVT);
1671 RetTyVTs.push_back(NVT);
1672 RetTyVTs.push_back(MVT::Other);
1673 SDNode *NC = DAG.getCall(RetTyVTs, Chain, Callee, Ops);
1674 Lo = SDOperand(NC, 0);
1675 Hi = SDOperand(NC, 1);
1677 // Insert the new chain mapping.
1678 AddLegalizedOperand(Op.getValue(1), Hi.getValue(2));
1683 case ISD::XOR: { // Simple logical operators -> two trivial pieces.
1684 SDOperand LL, LH, RL, RH;
1685 ExpandOp(Node->getOperand(0), LL, LH);
1686 ExpandOp(Node->getOperand(1), RL, RH);
1687 Lo = DAG.getNode(Node->getOpcode(), NVT, LL, RL);
1688 Hi = DAG.getNode(Node->getOpcode(), NVT, LH, RH);
1692 SDOperand C, LL, LH, RL, RH;
1694 switch (getTypeAction(Node->getOperand(0).getValueType())) {
1695 case Expand: assert(0 && "It's impossible to expand bools");
1697 C = LegalizeOp(Node->getOperand(0)); // Legalize the condition.
1700 C = PromoteOp(Node->getOperand(0)); // Promote the condition.
1703 ExpandOp(Node->getOperand(1), LL, LH);
1704 ExpandOp(Node->getOperand(2), RL, RH);
1705 Lo = DAG.getNode(ISD::SELECT, NVT, C, LL, RL);
1706 Hi = DAG.getNode(ISD::SELECT, NVT, C, LH, RH);
1709 case ISD::SIGN_EXTEND: {
1710 // The low part is just a sign extension of the input (which degenerates to
1712 Lo = DAG.getNode(ISD::SIGN_EXTEND, NVT, LegalizeOp(Node->getOperand(0)));
1714 // The high part is obtained by SRA'ing all but one of the bits of the lo
1716 unsigned LoSize = MVT::getSizeInBits(Lo.getValueType());
1717 Hi = DAG.getNode(ISD::SRA, NVT, Lo, DAG.getConstant(LoSize-1,
1718 TLI.getShiftAmountTy()));
1721 case ISD::ZERO_EXTEND:
1722 // The low part is just a zero extension of the input (which degenerates to
1724 Lo = DAG.getNode(ISD::ZERO_EXTEND, NVT, LegalizeOp(Node->getOperand(0)));
1726 // The high part is just a zero.
1727 Hi = DAG.getConstant(0, NVT);
1730 // These operators cannot be expanded directly, emit them as calls to
1731 // library functions.
1732 case ISD::FP_TO_SINT:
1733 if (Node->getOperand(0).getValueType() == MVT::f32)
1734 Lo = ExpandLibCall("__fixsfdi", Node, Hi);
1736 Lo = ExpandLibCall("__fixdfdi", Node, Hi);
1738 case ISD::FP_TO_UINT:
1739 if (Node->getOperand(0).getValueType() == MVT::f32)
1740 Lo = ExpandLibCall("__fixunssfdi", Node, Hi);
1742 Lo = ExpandLibCall("__fixunsdfdi", Node, Hi);
1746 // If we can emit an efficient shift operation, do so now.
1747 if (ExpandShift(ISD::SHL, Node->getOperand(0), Node->getOperand(1), Lo, Hi))
1749 // Otherwise, emit a libcall.
1750 Lo = ExpandLibCall("__ashldi3", Node, Hi);
1754 // If we can emit an efficient shift operation, do so now.
1755 if (ExpandShift(ISD::SRA, Node->getOperand(0), Node->getOperand(1), Lo, Hi))
1757 // Otherwise, emit a libcall.
1758 Lo = ExpandLibCall("__ashrdi3", Node, Hi);
1761 // If we can emit an efficient shift operation, do so now.
1762 if (ExpandShift(ISD::SRL, Node->getOperand(0), Node->getOperand(1), Lo, Hi))
1764 // Otherwise, emit a libcall.
1765 Lo = ExpandLibCall("__lshrdi3", Node, Hi);
1769 ExpandAddSub(true, Node->getOperand(0), Node->getOperand(1), Lo, Hi);
1772 ExpandAddSub(false, Node->getOperand(0), Node->getOperand(1), Lo, Hi);
1774 case ISD::MUL: Lo = ExpandLibCall("__muldi3" , Node, Hi); break;
1775 case ISD::SDIV: Lo = ExpandLibCall("__divdi3" , Node, Hi); break;
1776 case ISD::UDIV: Lo = ExpandLibCall("__udivdi3", Node, Hi); break;
1777 case ISD::SREM: Lo = ExpandLibCall("__moddi3" , Node, Hi); break;
1778 case ISD::UREM: Lo = ExpandLibCall("__umoddi3", Node, Hi); break;
1781 // Remember in a map if the values will be reused later.
1782 if (!Node->hasOneUse()) {
1783 bool isNew = ExpandedNodes.insert(std::make_pair(Op,
1784 std::make_pair(Lo, Hi))).second;
1785 assert(isNew && "Value already expanded?!?");
1790 // SelectionDAG::Legalize - This is the entry point for the file.
1792 void SelectionDAG::Legalize() {
1793 /// run - This is the main entry point to this class.
1795 SelectionDAGLegalize(*this).Run();