1 //===- InstCombineCasts.cpp -----------------------------------------------===//
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 the visit functions for cast operations.
12 //===----------------------------------------------------------------------===//
14 #include "InstCombine.h"
15 #include "llvm/Target/TargetData.h"
16 #include "llvm/Support/PatternMatch.h"
18 using namespace PatternMatch;
20 /// CanEvaluateInDifferentType - Return true if we can take the specified value
21 /// and return it as type Ty without inserting any new casts and without
22 /// changing the computed value. This is used by code that tries to decide
23 /// whether promoting or shrinking integer operations to wider or smaller types
24 /// will allow us to eliminate a truncate or extend.
26 /// This is a truncation operation if Ty is smaller than V->getType(), or an
27 /// extension operation if Ty is larger.
29 /// If CastOpc is a truncation, then Ty will be a type smaller than V. We
30 /// should return true if trunc(V) can be computed by computing V in the smaller
31 /// type. If V is an instruction, then trunc(inst(x,y)) can be computed as
32 /// inst(trunc(x),trunc(y)), which only makes sense if x and y can be
33 /// efficiently truncated.
35 /// If CastOpc is a sext or zext, we are asking if the low bits of the value can
36 /// bit computed in a larger type, which is then and'd or sext_in_reg'd to get
38 bool InstCombiner::CanEvaluateInDifferentType(Value *V, const Type *Ty,
40 int &NumCastsRemoved){
41 // We can always evaluate constants in another type.
45 Instruction *I = dyn_cast<Instruction>(V);
48 const Type *OrigTy = V->getType();
50 // If this is an extension or truncate, we can often eliminate it.
51 if (isa<TruncInst>(I) || isa<ZExtInst>(I) || isa<SExtInst>(I)) {
52 // If this is a cast from the destination type, we can trivially eliminate
53 // it, and this will remove a cast overall.
54 if (I->getOperand(0)->getType() == Ty) {
55 // If the first operand is itself a cast, and is eliminable, do not count
56 // this as an eliminable cast. We would prefer to eliminate those two
58 if (!isa<CastInst>(I->getOperand(0)) && I->hasOneUse())
64 // We can't extend or shrink something that has multiple uses: doing so would
65 // require duplicating the instruction in general, which isn't profitable.
66 if (!I->hasOneUse()) return false;
68 unsigned Opc = I->getOpcode();
70 case Instruction::Add:
71 case Instruction::Sub:
72 case Instruction::Mul:
73 case Instruction::And:
75 case Instruction::Xor:
76 // These operators can all arbitrarily be extended or truncated.
77 return CanEvaluateInDifferentType(I->getOperand(0), Ty, CastOpc,
79 CanEvaluateInDifferentType(I->getOperand(1), Ty, CastOpc,
82 case Instruction::UDiv:
83 case Instruction::URem: {
84 // UDiv and URem can be truncated if all the truncated bits are zero.
85 uint32_t OrigBitWidth = OrigTy->getScalarSizeInBits();
86 uint32_t BitWidth = Ty->getScalarSizeInBits();
87 if (BitWidth < OrigBitWidth) {
88 APInt Mask = APInt::getHighBitsSet(OrigBitWidth, OrigBitWidth-BitWidth);
89 if (MaskedValueIsZero(I->getOperand(0), Mask) &&
90 MaskedValueIsZero(I->getOperand(1), Mask)) {
91 return CanEvaluateInDifferentType(I->getOperand(0), Ty, CastOpc,
93 CanEvaluateInDifferentType(I->getOperand(1), Ty, CastOpc,
99 case Instruction::Shl:
100 // If we are truncating the result of this SHL, and if it's a shift of a
101 // constant amount, we can always perform a SHL in a smaller type.
102 if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) {
103 uint32_t BitWidth = Ty->getScalarSizeInBits();
104 if (BitWidth < OrigTy->getScalarSizeInBits() &&
105 CI->getLimitedValue(BitWidth) < BitWidth)
106 return CanEvaluateInDifferentType(I->getOperand(0), Ty, CastOpc,
110 case Instruction::LShr:
111 // If this is a truncate of a logical shr, we can truncate it to a smaller
112 // lshr iff we know that the bits we would otherwise be shifting in are
114 if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) {
115 uint32_t OrigBitWidth = OrigTy->getScalarSizeInBits();
116 uint32_t BitWidth = Ty->getScalarSizeInBits();
117 if (BitWidth < OrigBitWidth &&
118 MaskedValueIsZero(I->getOperand(0),
119 APInt::getHighBitsSet(OrigBitWidth, OrigBitWidth-BitWidth)) &&
120 CI->getLimitedValue(BitWidth) < BitWidth) {
121 return CanEvaluateInDifferentType(I->getOperand(0), Ty, CastOpc,
126 case Instruction::ZExt:
127 case Instruction::SExt:
128 case Instruction::Trunc:
129 // If this is the same kind of case as our original (e.g. zext+zext), we
130 // can safely replace it. Note that replacing it does not reduce the number
131 // of casts in the input.
135 // sext (zext ty1), ty2 -> zext ty2
136 if (CastOpc == Instruction::SExt && Opc == Instruction::ZExt)
139 case Instruction::Select: {
140 SelectInst *SI = cast<SelectInst>(I);
141 return CanEvaluateInDifferentType(SI->getTrueValue(), Ty, CastOpc,
143 CanEvaluateInDifferentType(SI->getFalseValue(), Ty, CastOpc,
146 case Instruction::PHI: {
147 // We can change a phi if we can change all operands.
148 PHINode *PN = cast<PHINode>(I);
149 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
150 if (!CanEvaluateInDifferentType(PN->getIncomingValue(i), Ty, CastOpc,
156 // TODO: Can handle more cases here.
163 /// EvaluateInDifferentType - Given an expression that
164 /// CanEvaluateInDifferentType returns true for, actually insert the code to
165 /// evaluate the expression.
166 Value *InstCombiner::EvaluateInDifferentType(Value *V, const Type *Ty,
168 if (Constant *C = dyn_cast<Constant>(V))
169 return ConstantExpr::getIntegerCast(C, Ty, isSigned /*Sext or ZExt*/);
171 // Otherwise, it must be an instruction.
172 Instruction *I = cast<Instruction>(V);
173 Instruction *Res = 0;
174 unsigned Opc = I->getOpcode();
176 case Instruction::Add:
177 case Instruction::Sub:
178 case Instruction::Mul:
179 case Instruction::And:
180 case Instruction::Or:
181 case Instruction::Xor:
182 case Instruction::AShr:
183 case Instruction::LShr:
184 case Instruction::Shl:
185 case Instruction::UDiv:
186 case Instruction::URem: {
187 Value *LHS = EvaluateInDifferentType(I->getOperand(0), Ty, isSigned);
188 Value *RHS = EvaluateInDifferentType(I->getOperand(1), Ty, isSigned);
189 Res = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
192 case Instruction::Trunc:
193 case Instruction::ZExt:
194 case Instruction::SExt:
195 // If the source type of the cast is the type we're trying for then we can
196 // just return the source. There's no need to insert it because it is not
198 if (I->getOperand(0)->getType() == Ty)
199 return I->getOperand(0);
201 // Otherwise, must be the same type of cast, so just reinsert a new one.
202 Res = CastInst::Create(cast<CastInst>(I)->getOpcode(), I->getOperand(0),Ty);
204 case Instruction::Select: {
205 Value *True = EvaluateInDifferentType(I->getOperand(1), Ty, isSigned);
206 Value *False = EvaluateInDifferentType(I->getOperand(2), Ty, isSigned);
207 Res = SelectInst::Create(I->getOperand(0), True, False);
210 case Instruction::PHI: {
211 PHINode *OPN = cast<PHINode>(I);
212 PHINode *NPN = PHINode::Create(Ty);
213 for (unsigned i = 0, e = OPN->getNumIncomingValues(); i != e; ++i) {
214 Value *V =EvaluateInDifferentType(OPN->getIncomingValue(i), Ty, isSigned);
215 NPN->addIncoming(V, OPN->getIncomingBlock(i));
221 // TODO: Can handle more cases here.
222 llvm_unreachable("Unreachable!");
227 return InsertNewInstBefore(Res, *I);
231 /// This function is a wrapper around CastInst::isEliminableCastPair. It
232 /// simply extracts arguments and returns what that function returns.
233 static Instruction::CastOps
234 isEliminableCastPair(
235 const CastInst *CI, ///< The first cast instruction
236 unsigned opcode, ///< The opcode of the second cast instruction
237 const Type *DstTy, ///< The target type for the second cast instruction
238 TargetData *TD ///< The target data for pointer size
241 const Type *SrcTy = CI->getOperand(0)->getType(); // A from above
242 const Type *MidTy = CI->getType(); // B from above
244 // Get the opcodes of the two Cast instructions
245 Instruction::CastOps firstOp = Instruction::CastOps(CI->getOpcode());
246 Instruction::CastOps secondOp = Instruction::CastOps(opcode);
248 unsigned Res = CastInst::isEliminableCastPair(firstOp, secondOp, SrcTy, MidTy,
250 TD ? TD->getIntPtrType(CI->getContext()) : 0);
252 // We don't want to form an inttoptr or ptrtoint that converts to an integer
253 // type that differs from the pointer size.
254 if ((Res == Instruction::IntToPtr &&
255 (!TD || SrcTy != TD->getIntPtrType(CI->getContext()))) ||
256 (Res == Instruction::PtrToInt &&
257 (!TD || DstTy != TD->getIntPtrType(CI->getContext()))))
260 return Instruction::CastOps(Res);
263 /// ValueRequiresCast - Return true if the cast from "V to Ty" actually results
264 /// in any code being generated. It does not require codegen if V is simple
265 /// enough or if the cast can be folded into other casts.
266 bool InstCombiner::ValueRequiresCast(Instruction::CastOps opcode,const Value *V,
268 if (V->getType() == Ty || isa<Constant>(V)) return false;
270 // If this is another cast that can be eliminated, it isn't codegen either.
271 if (const CastInst *CI = dyn_cast<CastInst>(V))
272 if (isEliminableCastPair(CI, opcode, Ty, TD))
278 /// @brief Implement the transforms common to all CastInst visitors.
279 Instruction *InstCombiner::commonCastTransforms(CastInst &CI) {
280 Value *Src = CI.getOperand(0);
282 // Many cases of "cast of a cast" are eliminable. If it's eliminable we just
284 if (CastInst *CSrc = dyn_cast<CastInst>(Src)) { // A->B->C cast
285 if (Instruction::CastOps opc =
286 isEliminableCastPair(CSrc, CI.getOpcode(), CI.getType(), TD)) {
287 // The first cast (CSrc) is eliminable so we need to fix up or replace
288 // the second cast (CI). CSrc will then have a good chance of being dead.
289 return CastInst::Create(opc, CSrc->getOperand(0), CI.getType());
293 // If we are casting a select then fold the cast into the select
294 if (SelectInst *SI = dyn_cast<SelectInst>(Src))
295 if (Instruction *NV = FoldOpIntoSelect(CI, SI))
298 // If we are casting a PHI then fold the cast into the PHI
299 if (isa<PHINode>(Src)) {
300 // We don't do this if this would create a PHI node with an illegal type if
301 // it is currently legal.
302 if (!isa<IntegerType>(Src->getType()) ||
303 !isa<IntegerType>(CI.getType()) ||
304 ShouldChangeType(CI.getType(), Src->getType()))
305 if (Instruction *NV = FoldOpIntoPhi(CI))
312 /// @brief Implement the transforms for cast of pointer (bitcast/ptrtoint)
313 Instruction *InstCombiner::commonPointerCastTransforms(CastInst &CI) {
314 Value *Src = CI.getOperand(0);
316 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Src)) {
317 // If casting the result of a getelementptr instruction with no offset, turn
318 // this into a cast of the original pointer!
319 if (GEP->hasAllZeroIndices()) {
320 // Changing the cast operand is usually not a good idea but it is safe
321 // here because the pointer operand is being replaced with another
322 // pointer operand so the opcode doesn't need to change.
324 CI.setOperand(0, GEP->getOperand(0));
328 // If the GEP has a single use, and the base pointer is a bitcast, and the
329 // GEP computes a constant offset, see if we can convert these three
330 // instructions into fewer. This typically happens with unions and other
331 // non-type-safe code.
332 if (TD && GEP->hasOneUse() && isa<BitCastInst>(GEP->getOperand(0))) {
333 if (GEP->hasAllConstantIndices()) {
334 // We are guaranteed to get a constant from EmitGEPOffset.
335 ConstantInt *OffsetV = cast<ConstantInt>(EmitGEPOffset(GEP));
336 int64_t Offset = OffsetV->getSExtValue();
338 // Get the base pointer input of the bitcast, and the type it points to.
339 Value *OrigBase = cast<BitCastInst>(GEP->getOperand(0))->getOperand(0);
340 const Type *GEPIdxTy =
341 cast<PointerType>(OrigBase->getType())->getElementType();
342 SmallVector<Value*, 8> NewIndices;
343 if (FindElementAtOffset(GEPIdxTy, Offset, NewIndices)) {
344 // If we were able to index down into an element, create the GEP
345 // and bitcast the result. This eliminates one bitcast, potentially
347 Value *NGEP = cast<GEPOperator>(GEP)->isInBounds() ?
348 Builder->CreateInBoundsGEP(OrigBase,
349 NewIndices.begin(), NewIndices.end()) :
350 Builder->CreateGEP(OrigBase, NewIndices.begin(), NewIndices.end());
353 if (isa<BitCastInst>(CI))
354 return new BitCastInst(NGEP, CI.getType());
355 assert(isa<PtrToIntInst>(CI));
356 return new PtrToIntInst(NGEP, CI.getType());
362 return commonCastTransforms(CI);
365 /// commonIntCastTransforms - This function implements the common transforms
366 /// for trunc, zext, and sext.
367 Instruction *InstCombiner::commonIntCastTransforms(CastInst &CI) {
368 if (Instruction *Result = commonCastTransforms(CI))
371 Value *Src = CI.getOperand(0);
372 const Type *SrcTy = Src->getType();
373 const Type *DestTy = CI.getType();
374 uint32_t SrcBitSize = SrcTy->getScalarSizeInBits();
375 uint32_t DestBitSize = DestTy->getScalarSizeInBits();
377 // See if we can simplify any instructions used by the LHS whose sole
378 // purpose is to compute bits we don't care about.
379 if (SimplifyDemandedInstructionBits(CI))
382 // If the source isn't an instruction or has more than one use then we
383 // can't do anything more.
384 Instruction *SrcI = dyn_cast<Instruction>(Src);
385 if (!SrcI || !Src->hasOneUse())
388 // Attempt to propagate the cast into the instruction for int->int casts.
389 int NumCastsRemoved = 0;
390 // Only do this if the dest type is a simple type, don't convert the
391 // expression tree to something weird like i93 unless the source is also
393 if ((isa<VectorType>(DestTy) ||
394 ShouldChangeType(SrcI->getType(), DestTy)) &&
395 CanEvaluateInDifferentType(SrcI, DestTy,
396 CI.getOpcode(), NumCastsRemoved)) {
397 // If this cast is a truncate, evaluting in a different type always
398 // eliminates the cast, so it is always a win. If this is a zero-extension,
399 // we need to do an AND to maintain the clear top-part of the computation,
400 // so we require that the input have eliminated at least one cast. If this
401 // is a sign extension, we insert two new casts (to do the extension) so we
402 // require that two casts have been eliminated.
403 bool DoXForm = false;
404 bool JustReplace = false;
405 switch (CI.getOpcode()) {
407 // All the others use floating point so we shouldn't actually
408 // get here because of the check above.
409 llvm_unreachable("Unknown cast type");
410 case Instruction::Trunc:
413 case Instruction::ZExt: {
414 DoXForm = NumCastsRemoved >= 1;
417 // If it's unnecessary to issue an AND to clear the high bits, it's
418 // always profitable to do this xform.
419 Value *TryRes = EvaluateInDifferentType(SrcI, DestTy, false);
420 APInt Mask(APInt::getBitsSet(DestBitSize, SrcBitSize, DestBitSize));
421 if (MaskedValueIsZero(TryRes, Mask))
422 return ReplaceInstUsesWith(CI, TryRes);
424 if (Instruction *TryI = dyn_cast<Instruction>(TryRes))
425 if (TryI->use_empty())
426 EraseInstFromFunction(*TryI);
430 case Instruction::SExt: {
431 DoXForm = NumCastsRemoved >= 2;
432 if (!DoXForm && !isa<TruncInst>(SrcI) && 0) {
433 // If we do not have to emit the truncate + sext pair, then it's always
434 // profitable to do this xform.
436 // It's not safe to eliminate the trunc + sext pair if one of the
437 // eliminated cast is a truncate. e.g.
438 // t2 = trunc i32 t1 to i16
439 // t3 = sext i16 t2 to i32
442 Value *TryRes = EvaluateInDifferentType(SrcI, DestTy, true);
443 unsigned NumSignBits = ComputeNumSignBits(TryRes);
444 if (NumSignBits > (DestBitSize - SrcBitSize))
445 return ReplaceInstUsesWith(CI, TryRes);
447 if (Instruction *TryI = dyn_cast<Instruction>(TryRes))
448 if (TryI->use_empty())
449 EraseInstFromFunction(*TryI);
456 DEBUG(errs() << "ICE: EvaluateInDifferentType converting expression type"
457 " to avoid cast: " << CI);
458 Value *Res = EvaluateInDifferentType(SrcI, DestTy,
459 CI.getOpcode() == Instruction::SExt);
461 // Just replace this cast with the result.
462 return ReplaceInstUsesWith(CI, Res);
464 assert(Res->getType() == DestTy);
465 switch (CI.getOpcode()) {
466 default: llvm_unreachable("Unknown cast type!");
467 case Instruction::Trunc:
468 // Just replace this cast with the result.
469 return ReplaceInstUsesWith(CI, Res);
470 case Instruction::ZExt: {
471 assert(SrcBitSize < DestBitSize && "Not a zext?");
473 // If the high bits are already zero, just replace this cast with the
475 APInt Mask(APInt::getBitsSet(DestBitSize, SrcBitSize, DestBitSize));
476 if (MaskedValueIsZero(Res, Mask))
477 return ReplaceInstUsesWith(CI, Res);
479 // We need to emit an AND to clear the high bits.
480 Constant *C = ConstantInt::get(CI.getContext(),
481 APInt::getLowBitsSet(DestBitSize, SrcBitSize));
482 return BinaryOperator::CreateAnd(Res, C);
484 case Instruction::SExt: {
485 // If the high bits are already filled with sign bit, just replace this
486 // cast with the result.
487 unsigned NumSignBits = ComputeNumSignBits(Res);
488 if (NumSignBits > (DestBitSize - SrcBitSize))
489 return ReplaceInstUsesWith(CI, Res);
491 // We need to emit a cast to truncate, then a cast to sext.
492 return new SExtInst(Builder->CreateTrunc(Res, Src->getType()), DestTy);
498 Value *Op0 = SrcI->getNumOperands() > 0 ? SrcI->getOperand(0) : 0;
499 Value *Op1 = SrcI->getNumOperands() > 1 ? SrcI->getOperand(1) : 0;
501 switch (SrcI->getOpcode()) {
502 case Instruction::Add:
503 case Instruction::Mul:
504 case Instruction::And:
505 case Instruction::Or:
506 case Instruction::Xor:
507 // If we are discarding information, rewrite.
508 if (DestBitSize < SrcBitSize && DestBitSize != 1) {
509 // Don't insert two casts unless at least one can be eliminated.
510 if (!ValueRequiresCast(CI.getOpcode(), Op1, DestTy) ||
511 !ValueRequiresCast(CI.getOpcode(), Op0, DestTy)) {
512 Value *Op0c = Builder->CreateTrunc(Op0, DestTy, Op0->getName());
513 Value *Op1c = Builder->CreateTrunc(Op1, DestTy, Op1->getName());
514 return BinaryOperator::Create(
515 cast<BinaryOperator>(SrcI)->getOpcode(), Op0c, Op1c);
519 // cast (xor bool X, true) to int --> xor (cast bool X to int), 1
520 if (isa<ZExtInst>(CI) && SrcBitSize == 1 &&
521 SrcI->getOpcode() == Instruction::Xor &&
522 Op1 == ConstantInt::getTrue(CI.getContext()) &&
523 (!Op0->hasOneUse() || !isa<CmpInst>(Op0))) {
524 Value *New = Builder->CreateZExt(Op0, DestTy, Op0->getName());
525 return BinaryOperator::CreateXor(New,
526 ConstantInt::get(CI.getType(), 1));
530 case Instruction::Shl: {
531 // Canonicalize trunc inside shl, if we can.
532 ConstantInt *CI = dyn_cast<ConstantInt>(Op1);
533 if (CI && DestBitSize < SrcBitSize &&
534 CI->getLimitedValue(DestBitSize) < DestBitSize) {
535 Value *Op0c = Builder->CreateTrunc(Op0, DestTy, Op0->getName());
536 Value *Op1c = Builder->CreateTrunc(Op1, DestTy, Op1->getName());
537 return BinaryOperator::CreateShl(Op0c, Op1c);
546 Instruction *InstCombiner::visitTrunc(TruncInst &CI) {
547 if (Instruction *Result = commonIntCastTransforms(CI))
550 Value *Src = CI.getOperand(0);
551 const Type *Ty = CI.getType();
552 uint32_t DestBitWidth = Ty->getScalarSizeInBits();
553 uint32_t SrcBitWidth = Src->getType()->getScalarSizeInBits();
555 // Canonicalize trunc x to i1 -> (icmp ne (and x, 1), 0)
556 if (DestBitWidth == 1) {
557 Constant *One = ConstantInt::get(Src->getType(), 1);
558 Src = Builder->CreateAnd(Src, One, "tmp");
559 Value *Zero = Constant::getNullValue(Src->getType());
560 return new ICmpInst(ICmpInst::ICMP_NE, Src, Zero);
563 // Optimize trunc(lshr(), c) to pull the shift through the truncate.
564 ConstantInt *ShAmtV = 0;
566 if (Src->hasOneUse() &&
567 match(Src, m_LShr(m_Value(ShiftOp), m_ConstantInt(ShAmtV)))) {
568 uint32_t ShAmt = ShAmtV->getLimitedValue(SrcBitWidth);
570 // Get a mask for the bits shifting in.
571 APInt Mask(APInt::getLowBitsSet(SrcBitWidth, ShAmt).shl(DestBitWidth));
572 if (MaskedValueIsZero(ShiftOp, Mask)) {
573 if (ShAmt >= DestBitWidth) // All zeros.
574 return ReplaceInstUsesWith(CI, Constant::getNullValue(Ty));
576 // Okay, we can shrink this. Truncate the input, then return a new
578 Value *V1 = Builder->CreateTrunc(ShiftOp, Ty, ShiftOp->getName());
579 Value *V2 = ConstantExpr::getTrunc(ShAmtV, Ty);
580 return BinaryOperator::CreateLShr(V1, V2);
587 /// transformZExtICmp - Transform (zext icmp) to bitwise / integer operations
588 /// in order to eliminate the icmp.
589 Instruction *InstCombiner::transformZExtICmp(ICmpInst *ICI, Instruction &CI,
591 // If we are just checking for a icmp eq of a single bit and zext'ing it
592 // to an integer, then shift the bit to the appropriate place and then
593 // cast to integer to avoid the comparison.
594 if (ConstantInt *Op1C = dyn_cast<ConstantInt>(ICI->getOperand(1))) {
595 const APInt &Op1CV = Op1C->getValue();
597 // zext (x <s 0) to i32 --> x>>u31 true if signbit set.
598 // zext (x >s -1) to i32 --> (x>>u31)^1 true if signbit clear.
599 if ((ICI->getPredicate() == ICmpInst::ICMP_SLT && Op1CV == 0) ||
600 (ICI->getPredicate() == ICmpInst::ICMP_SGT &&Op1CV.isAllOnesValue())) {
601 if (!DoXform) return ICI;
603 Value *In = ICI->getOperand(0);
604 Value *Sh = ConstantInt::get(In->getType(),
605 In->getType()->getScalarSizeInBits()-1);
606 In = Builder->CreateLShr(In, Sh, In->getName()+".lobit");
607 if (In->getType() != CI.getType())
608 In = Builder->CreateIntCast(In, CI.getType(), false/*ZExt*/, "tmp");
610 if (ICI->getPredicate() == ICmpInst::ICMP_SGT) {
611 Constant *One = ConstantInt::get(In->getType(), 1);
612 In = Builder->CreateXor(In, One, In->getName()+".not");
615 return ReplaceInstUsesWith(CI, In);
620 // zext (X == 0) to i32 --> X^1 iff X has only the low bit set.
621 // zext (X == 0) to i32 --> (X>>1)^1 iff X has only the 2nd bit set.
622 // zext (X == 1) to i32 --> X iff X has only the low bit set.
623 // zext (X == 2) to i32 --> X>>1 iff X has only the 2nd bit set.
624 // zext (X != 0) to i32 --> X iff X has only the low bit set.
625 // zext (X != 0) to i32 --> X>>1 iff X has only the 2nd bit set.
626 // zext (X != 1) to i32 --> X^1 iff X has only the low bit set.
627 // zext (X != 2) to i32 --> (X>>1)^1 iff X has only the 2nd bit set.
628 if ((Op1CV == 0 || Op1CV.isPowerOf2()) &&
629 // This only works for EQ and NE
631 // If Op1C some other power of two, convert:
632 uint32_t BitWidth = Op1C->getType()->getBitWidth();
633 APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
634 APInt TypeMask(APInt::getAllOnesValue(BitWidth));
635 ComputeMaskedBits(ICI->getOperand(0), TypeMask, KnownZero, KnownOne);
637 APInt KnownZeroMask(~KnownZero);
638 if (KnownZeroMask.isPowerOf2()) { // Exactly 1 possible 1?
639 if (!DoXform) return ICI;
641 bool isNE = ICI->getPredicate() == ICmpInst::ICMP_NE;
642 if (Op1CV != 0 && (Op1CV != KnownZeroMask)) {
643 // (X&4) == 2 --> false
644 // (X&4) != 2 --> true
645 Constant *Res = ConstantInt::get(Type::getInt1Ty(CI.getContext()),
647 Res = ConstantExpr::getZExt(Res, CI.getType());
648 return ReplaceInstUsesWith(CI, Res);
651 uint32_t ShiftAmt = KnownZeroMask.logBase2();
652 Value *In = ICI->getOperand(0);
654 // Perform a logical shr by shiftamt.
655 // Insert the shift to put the result in the low bit.
656 In = Builder->CreateLShr(In, ConstantInt::get(In->getType(),ShiftAmt),
657 In->getName()+".lobit");
660 if ((Op1CV != 0) == isNE) { // Toggle the low bit.
661 Constant *One = ConstantInt::get(In->getType(), 1);
662 In = Builder->CreateXor(In, One, "tmp");
665 if (CI.getType() == In->getType())
666 return ReplaceInstUsesWith(CI, In);
668 return CastInst::CreateIntegerCast(In, CI.getType(), false/*ZExt*/);
673 // icmp ne A, B is equal to xor A, B when A and B only really have one bit.
674 // It is also profitable to transform icmp eq into not(xor(A, B)) because that
675 // may lead to additional simplifications.
676 if (ICI->isEquality() && CI.getType() == ICI->getOperand(0)->getType()) {
677 if (const IntegerType *ITy = dyn_cast<IntegerType>(CI.getType())) {
678 uint32_t BitWidth = ITy->getBitWidth();
679 Value *LHS = ICI->getOperand(0);
680 Value *RHS = ICI->getOperand(1);
682 APInt KnownZeroLHS(BitWidth, 0), KnownOneLHS(BitWidth, 0);
683 APInt KnownZeroRHS(BitWidth, 0), KnownOneRHS(BitWidth, 0);
684 APInt TypeMask(APInt::getAllOnesValue(BitWidth));
685 ComputeMaskedBits(LHS, TypeMask, KnownZeroLHS, KnownOneLHS);
686 ComputeMaskedBits(RHS, TypeMask, KnownZeroRHS, KnownOneRHS);
688 if (KnownZeroLHS == KnownZeroRHS && KnownOneLHS == KnownOneRHS) {
689 APInt KnownBits = KnownZeroLHS | KnownOneLHS;
690 APInt UnknownBit = ~KnownBits;
691 if (UnknownBit.countPopulation() == 1) {
692 if (!DoXform) return ICI;
694 Value *Result = Builder->CreateXor(LHS, RHS);
696 // Mask off any bits that are set and won't be shifted away.
697 if (KnownOneLHS.uge(UnknownBit))
698 Result = Builder->CreateAnd(Result,
699 ConstantInt::get(ITy, UnknownBit));
701 // Shift the bit we're testing down to the lsb.
702 Result = Builder->CreateLShr(
703 Result, ConstantInt::get(ITy, UnknownBit.countTrailingZeros()));
705 if (ICI->getPredicate() == ICmpInst::ICMP_EQ)
706 Result = Builder->CreateXor(Result, ConstantInt::get(ITy, 1));
707 Result->takeName(ICI);
708 return ReplaceInstUsesWith(CI, Result);
717 Instruction *InstCombiner::visitZExt(ZExtInst &CI) {
718 // If one of the common conversion will work, do it.
719 if (Instruction *Result = commonIntCastTransforms(CI))
722 Value *Src = CI.getOperand(0);
724 // If this is a TRUNC followed by a ZEXT then we are dealing with integral
725 // types and if the sizes are just right we can convert this into a logical
726 // 'and' which will be much cheaper than the pair of casts.
727 if (TruncInst *CSrc = dyn_cast<TruncInst>(Src)) { // A->B->C cast
728 // Get the sizes of the types involved. We know that the intermediate type
729 // will be smaller than A or C, but don't know the relation between A and C.
730 Value *A = CSrc->getOperand(0);
731 unsigned SrcSize = A->getType()->getScalarSizeInBits();
732 unsigned MidSize = CSrc->getType()->getScalarSizeInBits();
733 unsigned DstSize = CI.getType()->getScalarSizeInBits();
734 // If we're actually extending zero bits, then if
735 // SrcSize < DstSize: zext(a & mask)
736 // SrcSize == DstSize: a & mask
737 // SrcSize > DstSize: trunc(a) & mask
738 if (SrcSize < DstSize) {
739 APInt AndValue(APInt::getLowBitsSet(SrcSize, MidSize));
740 Constant *AndConst = ConstantInt::get(A->getType(), AndValue);
741 Value *And = Builder->CreateAnd(A, AndConst, CSrc->getName()+".mask");
742 return new ZExtInst(And, CI.getType());
745 if (SrcSize == DstSize) {
746 APInt AndValue(APInt::getLowBitsSet(SrcSize, MidSize));
747 return BinaryOperator::CreateAnd(A, ConstantInt::get(A->getType(),
750 if (SrcSize > DstSize) {
751 Value *Trunc = Builder->CreateTrunc(A, CI.getType(), "tmp");
752 APInt AndValue(APInt::getLowBitsSet(DstSize, MidSize));
753 return BinaryOperator::CreateAnd(Trunc,
754 ConstantInt::get(Trunc->getType(),
759 if (ICmpInst *ICI = dyn_cast<ICmpInst>(Src))
760 return transformZExtICmp(ICI, CI);
762 BinaryOperator *SrcI = dyn_cast<BinaryOperator>(Src);
763 if (SrcI && SrcI->getOpcode() == Instruction::Or) {
764 // zext (or icmp, icmp) --> or (zext icmp), (zext icmp) if at least one
765 // of the (zext icmp) will be transformed.
766 ICmpInst *LHS = dyn_cast<ICmpInst>(SrcI->getOperand(0));
767 ICmpInst *RHS = dyn_cast<ICmpInst>(SrcI->getOperand(1));
768 if (LHS && RHS && LHS->hasOneUse() && RHS->hasOneUse() &&
769 (transformZExtICmp(LHS, CI, false) ||
770 transformZExtICmp(RHS, CI, false))) {
771 Value *LCast = Builder->CreateZExt(LHS, CI.getType(), LHS->getName());
772 Value *RCast = Builder->CreateZExt(RHS, CI.getType(), RHS->getName());
773 return BinaryOperator::Create(Instruction::Or, LCast, RCast);
777 // zext(trunc(t) & C) -> (t & zext(C)).
778 if (SrcI && SrcI->getOpcode() == Instruction::And && SrcI->hasOneUse())
779 if (ConstantInt *C = dyn_cast<ConstantInt>(SrcI->getOperand(1)))
780 if (TruncInst *TI = dyn_cast<TruncInst>(SrcI->getOperand(0))) {
781 Value *TI0 = TI->getOperand(0);
782 if (TI0->getType() == CI.getType())
784 BinaryOperator::CreateAnd(TI0,
785 ConstantExpr::getZExt(C, CI.getType()));
788 // zext((trunc(t) & C) ^ C) -> ((t & zext(C)) ^ zext(C)).
789 if (SrcI && SrcI->getOpcode() == Instruction::Xor && SrcI->hasOneUse())
790 if (ConstantInt *C = dyn_cast<ConstantInt>(SrcI->getOperand(1)))
791 if (BinaryOperator *And = dyn_cast<BinaryOperator>(SrcI->getOperand(0)))
792 if (And->getOpcode() == Instruction::And && And->hasOneUse() &&
793 And->getOperand(1) == C)
794 if (TruncInst *TI = dyn_cast<TruncInst>(And->getOperand(0))) {
795 Value *TI0 = TI->getOperand(0);
796 if (TI0->getType() == CI.getType()) {
797 Constant *ZC = ConstantExpr::getZExt(C, CI.getType());
798 Value *NewAnd = Builder->CreateAnd(TI0, ZC, "tmp");
799 return BinaryOperator::CreateXor(NewAnd, ZC);
806 Instruction *InstCombiner::visitSExt(SExtInst &CI) {
807 if (Instruction *I = commonIntCastTransforms(CI))
810 Value *Src = CI.getOperand(0);
812 // Canonicalize sign-extend from i1 to a select.
813 if (Src->getType() == Type::getInt1Ty(CI.getContext()))
814 return SelectInst::Create(Src,
815 Constant::getAllOnesValue(CI.getType()),
816 Constant::getNullValue(CI.getType()));
818 // See if the value being truncated is already sign extended. If so, just
819 // eliminate the trunc/sext pair.
820 if (Operator::getOpcode(Src) == Instruction::Trunc) {
821 Value *Op = cast<User>(Src)->getOperand(0);
822 unsigned OpBits = Op->getType()->getScalarSizeInBits();
823 unsigned MidBits = Src->getType()->getScalarSizeInBits();
824 unsigned DestBits = CI.getType()->getScalarSizeInBits();
825 unsigned NumSignBits = ComputeNumSignBits(Op);
827 if (OpBits == DestBits) {
828 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
829 // bits, it is already ready.
830 if (NumSignBits > DestBits-MidBits)
831 return ReplaceInstUsesWith(CI, Op);
832 } else if (OpBits < DestBits) {
833 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
834 // bits, just sext from i32.
835 if (NumSignBits > OpBits-MidBits)
836 return new SExtInst(Op, CI.getType(), "tmp");
838 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
839 // bits, just truncate to i32.
840 if (NumSignBits > OpBits-MidBits)
841 return new TruncInst(Op, CI.getType(), "tmp");
845 // If the input is a shl/ashr pair of a same constant, then this is a sign
846 // extension from a smaller value. If we could trust arbitrary bitwidth
847 // integers, we could turn this into a truncate to the smaller bit and then
848 // use a sext for the whole extension. Since we don't, look deeper and check
849 // for a truncate. If the source and dest are the same type, eliminate the
850 // trunc and extend and just do shifts. For example, turn:
851 // %a = trunc i32 %i to i8
853 // %c = ashr i8 %b, 6
854 // %d = sext i8 %c to i32
856 // %a = shl i32 %i, 30
857 // %d = ashr i32 %a, 30
859 ConstantInt *BA = 0, *CA = 0;
860 if (match(Src, m_AShr(m_Shl(m_Value(A), m_ConstantInt(BA)),
861 m_ConstantInt(CA))) &&
862 BA == CA && isa<TruncInst>(A)) {
863 Value *I = cast<TruncInst>(A)->getOperand(0);
864 if (I->getType() == CI.getType()) {
865 unsigned MidSize = Src->getType()->getScalarSizeInBits();
866 unsigned SrcDstSize = CI.getType()->getScalarSizeInBits();
867 unsigned ShAmt = CA->getZExtValue()+SrcDstSize-MidSize;
868 Constant *ShAmtV = ConstantInt::get(CI.getType(), ShAmt);
869 I = Builder->CreateShl(I, ShAmtV, CI.getName());
870 return BinaryOperator::CreateAShr(I, ShAmtV);
878 /// FitsInFPType - Return a Constant* for the specified FP constant if it fits
879 /// in the specified FP type without changing its value.
880 static Constant *FitsInFPType(ConstantFP *CFP, const fltSemantics &Sem) {
882 APFloat F = CFP->getValueAPF();
883 (void)F.convert(Sem, APFloat::rmNearestTiesToEven, &losesInfo);
885 return ConstantFP::get(CFP->getContext(), F);
889 /// LookThroughFPExtensions - If this is an fp extension instruction, look
890 /// through it until we get the source value.
891 static Value *LookThroughFPExtensions(Value *V) {
892 if (Instruction *I = dyn_cast<Instruction>(V))
893 if (I->getOpcode() == Instruction::FPExt)
894 return LookThroughFPExtensions(I->getOperand(0));
896 // If this value is a constant, return the constant in the smallest FP type
897 // that can accurately represent it. This allows us to turn
898 // (float)((double)X+2.0) into x+2.0f.
899 if (ConstantFP *CFP = dyn_cast<ConstantFP>(V)) {
900 if (CFP->getType() == Type::getPPC_FP128Ty(V->getContext()))
901 return V; // No constant folding of this.
902 // See if the value can be truncated to float and then reextended.
903 if (Value *V = FitsInFPType(CFP, APFloat::IEEEsingle))
905 if (CFP->getType() == Type::getDoubleTy(V->getContext()))
906 return V; // Won't shrink.
907 if (Value *V = FitsInFPType(CFP, APFloat::IEEEdouble))
909 // Don't try to shrink to various long double types.
915 Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
916 if (Instruction *I = commonCastTransforms(CI))
919 // If we have fptrunc(fadd (fpextend x), (fpextend y)), where x and y are
920 // smaller than the destination type, we can eliminate the truncate by doing
921 // the add as the smaller type. This applies to fadd/fsub/fmul/fdiv as well
922 // as many builtins (sqrt, etc).
923 BinaryOperator *OpI = dyn_cast<BinaryOperator>(CI.getOperand(0));
924 if (OpI && OpI->hasOneUse()) {
925 switch (OpI->getOpcode()) {
927 case Instruction::FAdd:
928 case Instruction::FSub:
929 case Instruction::FMul:
930 case Instruction::FDiv:
931 case Instruction::FRem:
932 const Type *SrcTy = OpI->getType();
933 Value *LHSTrunc = LookThroughFPExtensions(OpI->getOperand(0));
934 Value *RHSTrunc = LookThroughFPExtensions(OpI->getOperand(1));
935 if (LHSTrunc->getType() != SrcTy &&
936 RHSTrunc->getType() != SrcTy) {
937 unsigned DstSize = CI.getType()->getScalarSizeInBits();
938 // If the source types were both smaller than the destination type of
939 // the cast, do this xform.
940 if (LHSTrunc->getType()->getScalarSizeInBits() <= DstSize &&
941 RHSTrunc->getType()->getScalarSizeInBits() <= DstSize) {
942 LHSTrunc = Builder->CreateFPExt(LHSTrunc, CI.getType());
943 RHSTrunc = Builder->CreateFPExt(RHSTrunc, CI.getType());
944 return BinaryOperator::Create(OpI->getOpcode(), LHSTrunc, RHSTrunc);
953 Instruction *InstCombiner::visitFPExt(CastInst &CI) {
954 return commonCastTransforms(CI);
957 Instruction *InstCombiner::visitFPToUI(FPToUIInst &FI) {
958 Instruction *OpI = dyn_cast<Instruction>(FI.getOperand(0));
960 return commonCastTransforms(FI);
962 // fptoui(uitofp(X)) --> X
963 // fptoui(sitofp(X)) --> X
964 // This is safe if the intermediate type has enough bits in its mantissa to
965 // accurately represent all values of X. For example, do not do this with
966 // i64->float->i64. This is also safe for sitofp case, because any negative
967 // 'X' value would cause an undefined result for the fptoui.
968 if ((isa<UIToFPInst>(OpI) || isa<SIToFPInst>(OpI)) &&
969 OpI->getOperand(0)->getType() == FI.getType() &&
970 (int)FI.getType()->getScalarSizeInBits() < /*extra bit for sign */
971 OpI->getType()->getFPMantissaWidth())
972 return ReplaceInstUsesWith(FI, OpI->getOperand(0));
974 return commonCastTransforms(FI);
977 Instruction *InstCombiner::visitFPToSI(FPToSIInst &FI) {
978 Instruction *OpI = dyn_cast<Instruction>(FI.getOperand(0));
980 return commonCastTransforms(FI);
982 // fptosi(sitofp(X)) --> X
983 // fptosi(uitofp(X)) --> X
984 // This is safe if the intermediate type has enough bits in its mantissa to
985 // accurately represent all values of X. For example, do not do this with
986 // i64->float->i64. This is also safe for sitofp case, because any negative
987 // 'X' value would cause an undefined result for the fptoui.
988 if ((isa<UIToFPInst>(OpI) || isa<SIToFPInst>(OpI)) &&
989 OpI->getOperand(0)->getType() == FI.getType() &&
990 (int)FI.getType()->getScalarSizeInBits() <=
991 OpI->getType()->getFPMantissaWidth())
992 return ReplaceInstUsesWith(FI, OpI->getOperand(0));
994 return commonCastTransforms(FI);
997 Instruction *InstCombiner::visitUIToFP(CastInst &CI) {
998 return commonCastTransforms(CI);
1001 Instruction *InstCombiner::visitSIToFP(CastInst &CI) {
1002 return commonCastTransforms(CI);
1005 Instruction *InstCombiner::visitPtrToInt(PtrToIntInst &CI) {
1006 // If the destination integer type is smaller than the intptr_t type for
1007 // this target, do a ptrtoint to intptr_t then do a trunc. This allows the
1008 // trunc to be exposed to other transforms. Don't do this for extending
1009 // ptrtoint's, because we don't know if the target sign or zero extends its
1012 CI.getType()->getScalarSizeInBits() < TD->getPointerSizeInBits()) {
1013 Value *P = Builder->CreatePtrToInt(CI.getOperand(0),
1014 TD->getIntPtrType(CI.getContext()),
1016 return new TruncInst(P, CI.getType());
1019 return commonPointerCastTransforms(CI);
1023 Instruction *InstCombiner::visitIntToPtr(IntToPtrInst &CI) {
1024 // If the source integer type is larger than the intptr_t type for
1025 // this target, do a trunc to the intptr_t type, then inttoptr of it. This
1026 // allows the trunc to be exposed to other transforms. Don't do this for
1027 // extending inttoptr's, because we don't know if the target sign or zero
1028 // extends to pointers.
1029 if (TD && CI.getOperand(0)->getType()->getScalarSizeInBits() >
1030 TD->getPointerSizeInBits()) {
1031 Value *P = Builder->CreateTrunc(CI.getOperand(0),
1032 TD->getIntPtrType(CI.getContext()), "tmp");
1033 return new IntToPtrInst(P, CI.getType());
1036 if (Instruction *I = commonCastTransforms(CI))
1042 Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {
1043 // If the operands are integer typed then apply the integer transforms,
1044 // otherwise just apply the common ones.
1045 Value *Src = CI.getOperand(0);
1046 const Type *SrcTy = Src->getType();
1047 const Type *DestTy = CI.getType();
1049 if (isa<PointerType>(SrcTy)) {
1050 if (Instruction *I = commonPointerCastTransforms(CI))
1053 if (Instruction *Result = commonCastTransforms(CI))
1058 // Get rid of casts from one type to the same type. These are useless and can
1059 // be replaced by the operand.
1060 if (DestTy == Src->getType())
1061 return ReplaceInstUsesWith(CI, Src);
1063 if (const PointerType *DstPTy = dyn_cast<PointerType>(DestTy)) {
1064 const PointerType *SrcPTy = cast<PointerType>(SrcTy);
1065 const Type *DstElTy = DstPTy->getElementType();
1066 const Type *SrcElTy = SrcPTy->getElementType();
1068 // If the address spaces don't match, don't eliminate the bitcast, which is
1069 // required for changing types.
1070 if (SrcPTy->getAddressSpace() != DstPTy->getAddressSpace())
1073 // If we are casting a alloca to a pointer to a type of the same
1074 // size, rewrite the allocation instruction to allocate the "right" type.
1075 // There is no need to modify malloc calls because it is their bitcast that
1076 // needs to be cleaned up.
1077 if (AllocaInst *AI = dyn_cast<AllocaInst>(Src))
1078 if (Instruction *V = PromoteCastOfAllocation(CI, *AI))
1081 // If the source and destination are pointers, and this cast is equivalent
1082 // to a getelementptr X, 0, 0, 0... turn it into the appropriate gep.
1083 // This can enhance SROA and other transforms that want type-safe pointers.
1084 Constant *ZeroUInt =
1085 Constant::getNullValue(Type::getInt32Ty(CI.getContext()));
1086 unsigned NumZeros = 0;
1087 while (SrcElTy != DstElTy &&
1088 isa<CompositeType>(SrcElTy) && !isa<PointerType>(SrcElTy) &&
1089 SrcElTy->getNumContainedTypes() /* not "{}" */) {
1090 SrcElTy = cast<CompositeType>(SrcElTy)->getTypeAtIndex(ZeroUInt);
1094 // If we found a path from the src to dest, create the getelementptr now.
1095 if (SrcElTy == DstElTy) {
1096 SmallVector<Value*, 8> Idxs(NumZeros+1, ZeroUInt);
1097 return GetElementPtrInst::CreateInBounds(Src, Idxs.begin(), Idxs.end(),"",
1098 ((Instruction*) NULL));
1102 if (const VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) {
1103 if (DestVTy->getNumElements() == 1) {
1104 if (!isa<VectorType>(SrcTy)) {
1105 Value *Elem = Builder->CreateBitCast(Src, DestVTy->getElementType());
1106 return InsertElementInst::Create(UndefValue::get(DestTy), Elem,
1107 Constant::getNullValue(Type::getInt32Ty(CI.getContext())));
1109 // FIXME: Canonicalize bitcast(insertelement) -> insertelement(bitcast)
1113 if (const VectorType *SrcVTy = dyn_cast<VectorType>(SrcTy)) {
1114 if (SrcVTy->getNumElements() == 1) {
1115 if (!isa<VectorType>(DestTy)) {
1117 Builder->CreateExtractElement(Src,
1118 Constant::getNullValue(Type::getInt32Ty(CI.getContext())));
1119 return CastInst::Create(Instruction::BitCast, Elem, DestTy);
1124 if (ShuffleVectorInst *SVI = dyn_cast<ShuffleVectorInst>(Src)) {
1125 if (SVI->hasOneUse()) {
1126 // Okay, we have (bitconvert (shuffle ..)). Check to see if this is
1127 // a bitconvert to a vector with the same # elts.
1128 if (isa<VectorType>(DestTy) &&
1129 cast<VectorType>(DestTy)->getNumElements() ==
1130 SVI->getType()->getNumElements() &&
1131 SVI->getType()->getNumElements() ==
1132 cast<VectorType>(SVI->getOperand(0)->getType())->getNumElements()) {
1134 // If either of the operands is a cast from CI.getType(), then
1135 // evaluating the shuffle in the casted destination's type will allow
1136 // us to eliminate at least one cast.
1137 if (((Tmp = dyn_cast<CastInst>(SVI->getOperand(0))) &&
1138 Tmp->getOperand(0)->getType() == DestTy) ||
1139 ((Tmp = dyn_cast<CastInst>(SVI->getOperand(1))) &&
1140 Tmp->getOperand(0)->getType() == DestTy)) {
1141 Value *LHS = Builder->CreateBitCast(SVI->getOperand(0), DestTy);
1142 Value *RHS = Builder->CreateBitCast(SVI->getOperand(1), DestTy);
1143 // Return a new shuffle vector. Use the same element ID's, as we
1144 // know the vector types match #elts.
1145 return new ShuffleVectorInst(LHS, RHS, SVI->getOperand(2));