1 //===-- ConstantFolding.cpp - Analyze constant folding possibilities ------===//
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 family of functions determines the possibility of performing constant
13 //===----------------------------------------------------------------------===//
15 #include "llvm/Analysis/ConstantFolding.h"
16 #include "llvm/Constants.h"
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/Function.h"
19 #include "llvm/Instructions.h"
20 #include "llvm/Intrinsics.h"
21 #include "llvm/ADT/SmallVector.h"
22 #include "llvm/ADT/StringMap.h"
23 #include "llvm/Target/TargetData.h"
24 #include "llvm/Support/GetElementPtrTypeIterator.h"
25 #include "llvm/Support/MathExtras.h"
30 //===----------------------------------------------------------------------===//
31 // Constant Folding internal helper functions
32 //===----------------------------------------------------------------------===//
34 /// IsConstantOffsetFromGlobal - If this constant is actually a constant offset
35 /// from a global, return the global and the constant. Because of
36 /// constantexprs, this function is recursive.
37 static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
38 int64_t &Offset, const TargetData &TD) {
39 // Trivial case, constant is the global.
40 if ((GV = dyn_cast<GlobalValue>(C))) {
45 // Otherwise, if this isn't a constant expr, bail out.
46 ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
47 if (!CE) return false;
49 // Look through ptr->int and ptr->ptr casts.
50 if (CE->getOpcode() == Instruction::PtrToInt ||
51 CE->getOpcode() == Instruction::BitCast)
52 return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD);
54 // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
55 if (CE->getOpcode() == Instruction::GetElementPtr) {
56 // Cannot compute this if the element type of the pointer is missing size
58 if (!cast<PointerType>(CE->getOperand(0)->getType())
59 ->getElementType()->isSized())
62 // If the base isn't a global+constant, we aren't either.
63 if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD))
66 // Otherwise, add any offset that our operands provide.
67 gep_type_iterator GTI = gep_type_begin(CE);
68 for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i, ++GTI) {
69 ConstantInt *CI = dyn_cast<ConstantInt>(CE->getOperand(i));
70 if (!CI) return false; // Index isn't a simple constant?
71 if (CI->getZExtValue() == 0) continue; // Not adding anything.
73 if (const StructType *ST = dyn_cast<StructType>(*GTI)) {
75 Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue());
77 const SequentialType *SQT = cast<SequentialType>(*GTI);
78 Offset += TD.getABITypeSize(SQT->getElementType())*CI->getSExtValue();
88 /// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression.
89 /// Attempt to symbolically evaluate the result of a binary operator merging
90 /// these together. If target data info is available, it is provided as TD,
91 /// otherwise TD is null.
92 static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
93 Constant *Op1, const TargetData *TD){
96 // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl.
97 // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute
101 // If the constant expr is something like &A[123] - &A[4].f, fold this into a
102 // constant. This happens frequently when iterating over a global array.
103 if (Opc == Instruction::Sub && TD) {
104 GlobalValue *GV1, *GV2;
105 int64_t Offs1, Offs2;
107 if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD))
108 if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) &&
110 // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow.
111 return ConstantInt::get(Op0->getType(), Offs1-Offs2);
115 // TODO: Fold icmp setne/seteq as well.
119 /// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP
120 /// constant expression, do so.
121 static Constant *SymbolicallyEvaluateGEP(Constant* const* Ops, unsigned NumOps,
122 const Type *ResultTy,
123 const TargetData *TD) {
124 Constant *Ptr = Ops[0];
125 if (!TD || !cast<PointerType>(Ptr->getType())->getElementType()->isSized())
128 uint64_t BasePtr = 0;
129 if (!Ptr->isNullValue()) {
130 // If this is a inttoptr from a constant int, we can fold this as the base,
131 // otherwise we can't.
132 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
133 if (CE->getOpcode() == Instruction::IntToPtr)
134 if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0)))
135 BasePtr = Base->getZExtValue();
141 // If this is a constant expr gep that is effectively computing an
142 // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12'
143 for (unsigned i = 1; i != NumOps; ++i)
144 if (!isa<ConstantInt>(Ops[i]))
147 uint64_t Offset = TD->getIndexedOffset(Ptr->getType(),
148 (Value**)Ops+1, NumOps-1);
149 Constant *C = ConstantInt::get(TD->getIntPtrType(), Offset+BasePtr);
150 return ConstantExpr::getIntToPtr(C, ResultTy);
153 /// FoldBitCast - Constant fold bitcast, symbolically evaluating it with
154 /// targetdata. Return 0 if unfoldable.
155 static Constant *FoldBitCast(Constant *C, const Type *DestTy,
156 const TargetData &TD) {
157 // If this is a bitcast from constant vector -> vector, fold it.
158 if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) {
159 if (const VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) {
160 // If the element types match, VMCore can fold it.
161 unsigned NumDstElt = DestVTy->getNumElements();
162 unsigned NumSrcElt = CV->getNumOperands();
163 if (NumDstElt == NumSrcElt)
166 const Type *SrcEltTy = CV->getType()->getElementType();
167 const Type *DstEltTy = DestVTy->getElementType();
169 // Otherwise, we're changing the number of elements in a vector, which
170 // requires endianness information to do the right thing. For example,
171 // bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
172 // folds to (little endian):
173 // <4 x i32> <i32 0, i32 0, i32 1, i32 0>
174 // and to (big endian):
175 // <4 x i32> <i32 0, i32 0, i32 0, i32 1>
177 // First thing is first. We only want to think about integer here, so if
178 // we have something in FP form, recast it as integer.
179 if (DstEltTy->isFloatingPoint()) {
180 // Fold to an vector of integers with same size as our FP type.
181 unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits();
182 const Type *DestIVTy = VectorType::get(IntegerType::get(FPWidth),
184 // Recursively handle this integer conversion, if possible.
185 C = FoldBitCast(C, DestIVTy, TD);
188 // Finally, VMCore can handle this now that #elts line up.
189 return ConstantExpr::getBitCast(C, DestTy);
192 // Okay, we know the destination is integer, if the input is FP, convert
193 // it to integer first.
194 if (SrcEltTy->isFloatingPoint()) {
195 unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
196 const Type *SrcIVTy = VectorType::get(IntegerType::get(FPWidth),
198 // Ask VMCore to do the conversion now that #elts line up.
199 C = ConstantExpr::getBitCast(C, SrcIVTy);
200 CV = dyn_cast<ConstantVector>(C);
201 if (!CV) return 0; // If VMCore wasn't able to fold it, bail out.
204 // Now we know that the input and output vectors are both integer vectors
205 // of the same size, and that their #elements is not the same. Do the
206 // conversion here, which depends on whether the input or output has
208 bool isLittleEndian = TD.isLittleEndian();
210 SmallVector<Constant*, 32> Result;
211 if (NumDstElt < NumSrcElt) {
212 // Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>)
213 Constant *Zero = Constant::getNullValue(DstEltTy);
214 unsigned Ratio = NumSrcElt/NumDstElt;
215 unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits();
217 for (unsigned i = 0; i != NumDstElt; ++i) {
218 // Build each element of the result.
219 Constant *Elt = Zero;
220 unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1);
221 for (unsigned j = 0; j != Ratio; ++j) {
222 Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(SrcElt++));
223 if (!Src) return 0; // Reject constantexpr elements.
225 // Zero extend the element to the right size.
226 Src = ConstantExpr::getZExt(Src, Elt->getType());
228 // Shift it to the right place, depending on endianness.
229 Src = ConstantExpr::getShl(Src,
230 ConstantInt::get(Src->getType(), ShiftAmt));
231 ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;
234 Elt = ConstantExpr::getOr(Elt, Src);
236 Result.push_back(Elt);
239 // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
240 unsigned Ratio = NumDstElt/NumSrcElt;
241 unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits();
243 // Loop over each source value, expanding into multiple results.
244 for (unsigned i = 0; i != NumSrcElt; ++i) {
245 Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(i));
246 if (!Src) return 0; // Reject constantexpr elements.
248 unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1);
249 for (unsigned j = 0; j != Ratio; ++j) {
250 // Shift the piece of the value into the right place, depending on
252 Constant *Elt = ConstantExpr::getLShr(Src,
253 ConstantInt::get(Src->getType(), ShiftAmt));
254 ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
256 // Truncate and remember this piece.
257 Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
262 return ConstantVector::get(&Result[0], Result.size());
270 //===----------------------------------------------------------------------===//
271 // Constant Folding public APIs
272 //===----------------------------------------------------------------------===//
275 /// ConstantFoldInstruction - Attempt to constant fold the specified
276 /// instruction. If successful, the constant result is returned, if not, null
277 /// is returned. Note that this function can only fail when attempting to fold
278 /// instructions like loads and stores, which have no constant expression form.
280 Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) {
281 if (PHINode *PN = dyn_cast<PHINode>(I)) {
282 if (PN->getNumIncomingValues() == 0)
283 return Constant::getNullValue(PN->getType());
285 Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0));
286 if (Result == 0) return 0;
288 // Handle PHI nodes specially here...
289 for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i)
290 if (PN->getIncomingValue(i) != Result && PN->getIncomingValue(i) != PN)
291 return 0; // Not all the same incoming constants...
293 // If we reach here, all incoming values are the same constant.
297 // Scan the operand list, checking to see if they are all constants, if so,
298 // hand off to ConstantFoldInstOperands.
299 SmallVector<Constant*, 8> Ops;
300 for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
301 if (Constant *Op = dyn_cast<Constant>(I->getOperand(i)))
304 return 0; // All operands not constant!
306 if (const CmpInst *CI = dyn_cast<CmpInst>(I))
307 return ConstantFoldCompareInstOperands(CI->getPredicate(),
308 &Ops[0], Ops.size(), TD);
310 return ConstantFoldInstOperands(I->getOpcode(), I->getType(),
311 &Ops[0], Ops.size(), TD);
314 /// ConstantFoldInstOperands - Attempt to constant fold an instruction with the
315 /// specified opcode and operands. If successful, the constant result is
316 /// returned, if not, null is returned. Note that this function can fail when
317 /// attempting to fold instructions like loads and stores, which have no
318 /// constant expression form.
320 Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy,
321 Constant* const* Ops, unsigned NumOps,
322 const TargetData *TD) {
323 // Handle easy binops first.
324 if (Instruction::isBinaryOp(Opcode)) {
325 if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1]))
326 if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD))
329 return ConstantExpr::get(Opcode, Ops[0], Ops[1]);
334 case Instruction::Call:
335 if (Function *F = dyn_cast<Function>(Ops[0]))
336 if (canConstantFoldCallTo(F))
337 return ConstantFoldCall(F, Ops+1, NumOps-1);
339 case Instruction::ICmp:
340 case Instruction::FCmp:
341 assert(0 &&"This function is invalid for compares: no predicate specified");
342 case Instruction::PtrToInt:
343 // If the input is a inttoptr, eliminate the pair. This requires knowing
344 // the width of a pointer, so it can't be done in ConstantExpr::getCast.
345 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) {
346 if (TD && CE->getOpcode() == Instruction::IntToPtr) {
347 Constant *Input = CE->getOperand(0);
348 unsigned InWidth = Input->getType()->getPrimitiveSizeInBits();
350 ConstantInt::get(APInt::getLowBitsSet(InWidth,
351 TD->getPointerSizeInBits()));
352 Input = ConstantExpr::getAnd(Input, Mask);
353 // Do a zext or trunc to get to the dest size.
354 return ConstantExpr::getIntegerCast(Input, DestTy, false);
357 return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
358 case Instruction::IntToPtr:
359 case Instruction::Trunc:
360 case Instruction::ZExt:
361 case Instruction::SExt:
362 case Instruction::FPTrunc:
363 case Instruction::FPExt:
364 case Instruction::UIToFP:
365 case Instruction::SIToFP:
366 case Instruction::FPToUI:
367 case Instruction::FPToSI:
368 return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
369 case Instruction::BitCast:
371 if (Constant *C = FoldBitCast(Ops[0], DestTy, *TD))
373 return ConstantExpr::getBitCast(Ops[0], DestTy);
374 case Instruction::Select:
375 return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
376 case Instruction::ExtractElement:
377 return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
378 case Instruction::InsertElement:
379 return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
380 case Instruction::ShuffleVector:
381 return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]);
382 case Instruction::GetElementPtr:
383 if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, DestTy, TD))
386 return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1);
390 /// ConstantFoldCompareInstOperands - Attempt to constant fold a compare
391 /// instruction (icmp/fcmp) with the specified operands. If it fails, it
392 /// returns a constant expression of the specified operands.
394 Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate,
395 Constant*const * Ops,
397 const TargetData *TD) {
398 // fold: icmp (inttoptr x), null -> icmp x, 0
399 // fold: icmp (ptrtoint x), 0 -> icmp x, null
400 // fold: icmp (inttoptr x), (inttoptr y) -> icmp x, y
401 // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y
403 // ConstantExpr::getCompare cannot do this, because it doesn't have TD
404 // around to know if bit truncation is happening.
405 if (ConstantExpr *CE0 = dyn_cast<ConstantExpr>(Ops[0])) {
406 if (TD && Ops[1]->isNullValue()) {
407 const Type *IntPtrTy = TD->getIntPtrType();
408 if (CE0->getOpcode() == Instruction::IntToPtr) {
409 // Convert the integer value to the right size to ensure we get the
410 // proper extension or truncation.
411 Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0),
413 Constant *NewOps[] = { C, Constant::getNullValue(C->getType()) };
414 return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD);
417 // Only do this transformation if the int is intptrty in size, otherwise
418 // there is a truncation or extension that we aren't modeling.
419 if (CE0->getOpcode() == Instruction::PtrToInt &&
420 CE0->getType() == IntPtrTy) {
421 Constant *C = CE0->getOperand(0);
422 Constant *NewOps[] = { C, Constant::getNullValue(C->getType()) };
424 return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD);
428 if (TD && isa<ConstantExpr>(Ops[1]) &&
429 cast<ConstantExpr>(Ops[1])->getOpcode() == CE0->getOpcode()) {
430 const Type *IntPtrTy = TD->getIntPtrType();
431 // Only do this transformation if the int is intptrty in size, otherwise
432 // there is a truncation or extension that we aren't modeling.
433 if ((CE0->getOpcode() == Instruction::IntToPtr &&
434 CE0->getOperand(0)->getType() == IntPtrTy &&
435 Ops[1]->getOperand(0)->getType() == IntPtrTy) ||
436 (CE0->getOpcode() == Instruction::PtrToInt &&
437 CE0->getType() == IntPtrTy &&
438 CE0->getOperand(0)->getType() == Ops[1]->getOperand(0)->getType())) {
439 Constant *NewOps[] = {
440 CE0->getOperand(0), cast<ConstantExpr>(Ops[1])->getOperand(0)
442 return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD);
446 return ConstantExpr::getCompare(Predicate, Ops[0], Ops[1]);
450 /// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a
451 /// getelementptr constantexpr, return the constant value being addressed by the
452 /// constant expression, or null if something is funny and we can't decide.
453 Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C,
455 if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType()))
456 return 0; // Do not allow stepping over the value!
458 // Loop over all of the operands, tracking down which value we are
460 gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE);
461 for (++I; I != E; ++I)
462 if (const StructType *STy = dyn_cast<StructType>(*I)) {
463 ConstantInt *CU = cast<ConstantInt>(I.getOperand());
464 assert(CU->getZExtValue() < STy->getNumElements() &&
465 "Struct index out of range!");
466 unsigned El = (unsigned)CU->getZExtValue();
467 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
468 C = CS->getOperand(El);
469 } else if (isa<ConstantAggregateZero>(C)) {
470 C = Constant::getNullValue(STy->getElementType(El));
471 } else if (isa<UndefValue>(C)) {
472 C = UndefValue::get(STy->getElementType(El));
476 } else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) {
477 if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) {
478 if (CI->getZExtValue() >= ATy->getNumElements())
480 if (ConstantArray *CA = dyn_cast<ConstantArray>(C))
481 C = CA->getOperand(CI->getZExtValue());
482 else if (isa<ConstantAggregateZero>(C))
483 C = Constant::getNullValue(ATy->getElementType());
484 else if (isa<UndefValue>(C))
485 C = UndefValue::get(ATy->getElementType());
488 } else if (const VectorType *PTy = dyn_cast<VectorType>(*I)) {
489 if (CI->getZExtValue() >= PTy->getNumElements())
491 if (ConstantVector *CP = dyn_cast<ConstantVector>(C))
492 C = CP->getOperand(CI->getZExtValue());
493 else if (isa<ConstantAggregateZero>(C))
494 C = Constant::getNullValue(PTy->getElementType());
495 else if (isa<UndefValue>(C))
496 C = UndefValue::get(PTy->getElementType());
509 //===----------------------------------------------------------------------===//
510 // Constant Folding for Calls
513 /// canConstantFoldCallTo - Return true if its even possible to fold a call to
514 /// the specified function.
516 llvm::canConstantFoldCallTo(const Function *F) {
517 switch (F->getIntrinsicID()) {
518 case Intrinsic::sqrt:
519 case Intrinsic::powi:
520 case Intrinsic::bswap:
521 case Intrinsic::ctpop:
522 case Intrinsic::ctlz:
523 case Intrinsic::cttz:
528 const ValueName *NameVal = F->getValueName();
529 if (NameVal == 0) return false;
530 const char *Str = NameVal->getKeyData();
531 unsigned Len = NameVal->getKeyLength();
533 // In these cases, the check of the length is required. We don't want to
534 // return true for a name like "cos\0blah" which strcmp would return equal to
535 // "cos", but has length 8.
537 default: return false;
540 return !strcmp(Str, "acos") || !strcmp(Str, "asin") ||
541 !strcmp(Str, "atan");
543 return !strcmp(Str, "atan2");
547 return !strcmp(Str, "cos");
549 return !strcmp(Str, "ceil") || !strcmp(Str, "cosf") ||
550 !strcmp(Str, "cosh");
554 return !strcmp(Str, "exp");
558 return !strcmp(Str, "fabs") || !strcmp(Str, "fmod");
560 return !strcmp(Str, "floor");
564 if (Len == 3 && !strcmp(Str, "log"))
566 if (Len == 5 && !strcmp(Str, "log10"))
570 if (Len == 3 && !strcmp(Str, "pow"))
575 return !strcmp(Str, "sin");
577 return !strcmp(Str, "sinh") || !strcmp(Str, "sqrt") ||
578 !strcmp(Str, "sinf");
580 return !strcmp(Str, "sqrtf");
583 if (Len == 3 && !strcmp(Str, "tan"))
585 else if (Len == 4 && !strcmp(Str, "tanh"))
591 static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
600 if (Ty == Type::FloatTy)
601 return ConstantFP::get(APFloat((float)V));
602 if (Ty == Type::DoubleTy)
603 return ConstantFP::get(APFloat(V));
604 assert(0 && "Can only constant fold float/double");
607 static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
617 if (Ty == Type::FloatTy)
618 return ConstantFP::get(APFloat((float)V));
619 if (Ty == Type::DoubleTy)
620 return ConstantFP::get(APFloat(V));
621 assert(0 && "Can only constant fold float/double");
624 /// ConstantFoldCall - Attempt to constant fold a call to the specified function
625 /// with the specified arguments, returning null if unsuccessful.
628 llvm::ConstantFoldCall(Function *F,
629 Constant* const* Operands, unsigned NumOperands) {
630 const ValueName *NameVal = F->getValueName();
631 if (NameVal == 0) return 0;
632 const char *Str = NameVal->getKeyData();
633 unsigned Len = NameVal->getKeyLength();
635 const Type *Ty = F->getReturnType();
636 if (NumOperands == 1) {
637 if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) {
638 if (Ty!=Type::FloatTy && Ty!=Type::DoubleTy)
640 /// Currently APFloat versions of these functions do not exist, so we use
641 /// the host native double versions. Float versions are not called
642 /// directly but for all these it is true (float)(f((double)arg)) ==
643 /// f(arg). Long double not supported yet.
644 double V = Ty==Type::FloatTy ? (double)Op->getValueAPF().convertToFloat():
645 Op->getValueAPF().convertToDouble();
648 if (Len == 4 && !strcmp(Str, "acos"))
649 return ConstantFoldFP(acos, V, Ty);
650 else if (Len == 4 && !strcmp(Str, "asin"))
651 return ConstantFoldFP(asin, V, Ty);
652 else if (Len == 4 && !strcmp(Str, "atan"))
653 return ConstantFoldFP(atan, V, Ty);
656 if (Len == 4 && !strcmp(Str, "ceil"))
657 return ConstantFoldFP(ceil, V, Ty);
658 else if (Len == 3 && !strcmp(Str, "cos"))
659 return ConstantFoldFP(cos, V, Ty);
660 else if (Len == 4 && !strcmp(Str, "cosh"))
661 return ConstantFoldFP(cosh, V, Ty);
662 else if (Len == 4 && !strcmp(Str, "cosf"))
663 return ConstantFoldFP(cos, V, Ty);
666 if (Len == 3 && !strcmp(Str, "exp"))
667 return ConstantFoldFP(exp, V, Ty);
670 if (Len == 4 && !strcmp(Str, "fabs"))
671 return ConstantFoldFP(fabs, V, Ty);
672 else if (Len == 5 && !strcmp(Str, "floor"))
673 return ConstantFoldFP(floor, V, Ty);
676 if (Len == 3 && !strcmp(Str, "log") && V > 0)
677 return ConstantFoldFP(log, V, Ty);
678 else if (Len == 5 && !strcmp(Str, "log10") && V > 0)
679 return ConstantFoldFP(log10, V, Ty);
680 else if (!strcmp(Str, "llvm.sqrt.f32") ||
681 !strcmp(Str, "llvm.sqrt.f64")) {
683 return ConstantFoldFP(sqrt, V, Ty);
685 return Constant::getNullValue(Ty);
689 if (Len == 3 && !strcmp(Str, "sin"))
690 return ConstantFoldFP(sin, V, Ty);
691 else if (Len == 4 && !strcmp(Str, "sinh"))
692 return ConstantFoldFP(sinh, V, Ty);
693 else if (Len == 4 && !strcmp(Str, "sqrt") && V >= 0)
694 return ConstantFoldFP(sqrt, V, Ty);
695 else if (Len == 5 && !strcmp(Str, "sqrtf") && V >= 0)
696 return ConstantFoldFP(sqrt, V, Ty);
697 else if (Len == 4 && !strcmp(Str, "sinf"))
698 return ConstantFoldFP(sin, V, Ty);
701 if (Len == 3 && !strcmp(Str, "tan"))
702 return ConstantFoldFP(tan, V, Ty);
703 else if (Len == 4 && !strcmp(Str, "tanh"))
704 return ConstantFoldFP(tanh, V, Ty);
709 } else if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) {
710 if (Len > 11 && !memcmp(Str, "llvm.bswap", 10))
711 return ConstantInt::get(Op->getValue().byteSwap());
712 else if (Len > 11 && !memcmp(Str, "llvm.ctpop", 10))
713 return ConstantInt::get(Ty, Op->getValue().countPopulation());
714 else if (Len > 10 && !memcmp(Str, "llvm.cttz", 9))
715 return ConstantInt::get(Ty, Op->getValue().countTrailingZeros());
716 else if (Len > 10 && !memcmp(Str, "llvm.ctlz", 9))
717 return ConstantInt::get(Ty, Op->getValue().countLeadingZeros());
719 } else if (NumOperands == 2) {
720 if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
721 if (Ty!=Type::FloatTy && Ty!=Type::DoubleTy)
723 double Op1V = Ty==Type::FloatTy ?
724 (double)Op1->getValueAPF().convertToFloat():
725 Op1->getValueAPF().convertToDouble();
726 if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
727 double Op2V = Ty==Type::FloatTy ?
728 (double)Op2->getValueAPF().convertToFloat():
729 Op2->getValueAPF().convertToDouble();
731 if (Len == 3 && !strcmp(Str, "pow")) {
732 return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
733 } else if (Len == 4 && !strcmp(Str, "fmod")) {
734 return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty);
735 } else if (Len == 5 && !strcmp(Str, "atan2")) {
736 return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
738 } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
739 if (!strcmp(Str, "llvm.powi.f32")) {
740 return ConstantFP::get(APFloat((float)std::pow((float)Op1V,
741 (int)Op2C->getZExtValue())));
742 } else if (!strcmp(Str, "llvm.powi.f64")) {
743 return ConstantFP::get(APFloat((double)std::pow((double)Op1V,
744 (int)Op2C->getZExtValue())));