ScalarEvolutionExpander.cpp revision cfeb6a450632f2a6cd05302633c8c2b8c90cfdfd
136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman//===- ScalarEvolutionExpander.cpp - Scalar Evolution Analysis --*- C++ -*-===// 236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// The LLVM Compiler Infrastructure 436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman//===----------------------------------------------------------------------===// 936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 1036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// This file contains the implementation of the scalar evolution expander, 1136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// which is used to generate the code corresponding to a given scalar evolution 1236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// expression. 1336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 1436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman//===----------------------------------------------------------------------===// 1536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman#include "llvm/Analysis/ScalarEvolutionExpander.h" 17e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling#include "llvm/Analysis/LoopInfo.h" 1836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begemanusing namespace llvm; 1936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 20ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner/// InsertCastOfTo - Insert a cast of V to the specified type, doing what 21ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner/// we can to share the casts. 223ba68b9eef2851dae8a9d1b18928c6fa2e3c5f87Reid SpencerValue *SCEVExpander::InsertCastOfTo(Instruction::CastOps opcode, Value *V, 233ba68b9eef2851dae8a9d1b18928c6fa2e3c5f87Reid Spencer const Type *Ty) { 24ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner // FIXME: keep track of the cast instruction. 25ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 26d977d8651a5cd26a3e1088267f31cade405f2adfReid Spencer return ConstantExpr::getCast(opcode, C, Ty); 27ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 28ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Argument *A = dyn_cast<Argument>(V)) { 29ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner // Check to see if there is already a cast! 30ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner for (Value::use_iterator UI = A->use_begin(), E = A->use_end(); 31ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner UI != E; ++UI) { 32ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if ((*UI)->getType() == Ty) 333913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (CastInst *CI = dyn_cast<CastInst>(cast<Instruction>(*UI))) 343913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (CI->getOpcode() == opcode) { 353913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz // If the cast isn't the first instruction of the function, move it. 363913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (BasicBlock::iterator(CI) != 373913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz A->getParent()->getEntryBlock().begin()) { 383913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz CI->moveBefore(A->getParent()->getEntryBlock().begin()); 393913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz } 403913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz return CI; 41ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 42ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 437cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif return CastInst::Create(opcode, V, Ty, V->getName(), 44d977d8651a5cd26a3e1088267f31cade405f2adfReid Spencer A->getParent()->getEntryBlock().begin()); 45ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 463913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 47ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner Instruction *I = cast<Instruction>(V); 483913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 49ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner // Check to see if there is already a cast. If there is, use it. 50ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); 51ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner UI != E; ++UI) { 52ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if ((*UI)->getType() == Ty) 533913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (CastInst *CI = dyn_cast<CastInst>(cast<Instruction>(*UI))) 543913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (CI->getOpcode() == opcode) { 553913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz BasicBlock::iterator It = I; ++It; 563913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (isa<InvokeInst>(I)) 573913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz It = cast<InvokeInst>(I)->getNormalDest()->begin(); 583913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz while (isa<PHINode>(It)) ++It; 593913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (It != BasicBlock::iterator(CI)) { 603913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz // Splice the cast immediately after the operand in question. 613913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz CI->moveBefore(It); 623913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz } 633913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz return CI; 64ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 65ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 66ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner BasicBlock::iterator IP = I; ++IP; 67ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(I)) 68ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner IP = II->getNormalDest()->begin(); 69ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner while (isa<PHINode>(IP)) ++IP; 707cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif return CastInst::Create(opcode, V, Ty, V->getName(), IP); 71ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner} 72ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 737fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// InsertBinop - Insert the specified binary operator, doing a small amount 747fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// of work to avoid inserting an obviously redundant operation. 757fec90ebf4ebe7aa73a6dd7d275c255587c041adChris LattnerValue *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, Value *LHS, 768a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz Value *RHS, Instruction *InsertPt) { 770f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman // Fold a binop with constant operands. 780f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(LHS)) 790f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(RHS)) 800f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman return ConstantExpr::get(Opcode, CLHS, CRHS); 810f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman 827fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner // Do a quick scan to see if we have this binop nearby. If so, reuse it. 837fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner unsigned ScanLimit = 6; 848a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz BasicBlock::iterator BlockBegin = InsertPt->getParent()->begin(); 858a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (InsertPt != BlockBegin) { 868a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // Scanning starts from the last instruction before InsertPt. 878a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz BasicBlock::iterator IP = InsertPt; 888a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz --IP; 898a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz for (; ScanLimit; --IP, --ScanLimit) { 908a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(IP)) 918a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (BinOp->getOpcode() == Opcode && BinOp->getOperand(0) == LHS && 928a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz BinOp->getOperand(1) == RHS) 938a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz return BinOp; 948a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (IP == BlockBegin) break; 958a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz } 967fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner } 978a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz 988a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // If we haven't found this binop, insert it. 997cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif return BinaryOperator::Create(Opcode, LHS, RHS, "tmp", InsertPt); 1007fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner} 1017fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner 10236f891bdf6cf38fcc655a0930ca18664e18518d4Nate BegemanValue *SCEVExpander::visitMulExpr(SCEVMulExpr *S) { 10336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman int FirstOp = 0; // Set if we should emit a subtract. 10436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getOperand(0))) 10536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (SC->getValue()->isAllOnesValue()) 10636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman FirstOp = 1; 10736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 10836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman int i = S->getNumOperands()-2; 109d19534add90a2a894af61523b830887097bb780bDan Gohman Value *V = expand(S->getOperand(i+1)); 11036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Emit a bunch of multiply instructions 11236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman for (; i >= FirstOp; --i) 113d19534add90a2a894af61523b830887097bb780bDan Gohman V = InsertBinop(Instruction::Mul, V, expand(S->getOperand(i)), 1147fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner InsertPt); 11536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // -1 * ... ---> 0 - ... 11636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (FirstOp == 1) 1177fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner V = InsertBinop(Instruction::Sub, Constant::getNullValue(V->getType()), V, 1187fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner InsertPt); 11936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman return V; 12036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 12136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12236f891bdf6cf38fcc655a0930ca18664e18518d4Nate BegemanValue *SCEVExpander::visitAddRecExpr(SCEVAddRecExpr *S) { 12336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Type *Ty = S->getType(); 12436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Loop *L = S->getLoop(); 12536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // We cannot yet do fp recurrences, e.g. the xform of {X,+,F} --> X+{0,+,F} 12642a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner assert(Ty->isInteger() && "Cannot expand fp recurrences yet!"); 12736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {X,+,F} --> X + {0,+,F} 129cfeb6a450632f2a6cd05302633c8c2b8c90cfdfdDan Gohman if (!S->getStart()->isZero()) { 130d19534add90a2a894af61523b830887097bb780bDan Gohman Value *Start = expand(S->getStart()); 13136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman std::vector<SCEVHandle> NewOps(S->op_begin(), S->op_end()); 132246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman NewOps[0] = SE.getIntegerSCEV(0, Ty); 133246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman Value *Rest = expand(SE.getAddRecExpr(NewOps, L)); 13436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // FIXME: look for an existing add to use. 1367fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner return InsertBinop(Instruction::Add, Rest, Start, InsertPt); 13736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 13836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {0,+,1} --> Insert a canonical induction variable into the loop! 14036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (S->getNumOperands() == 2 && 141246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman S->getOperand(1) == SE.getIntegerSCEV(1, Ty)) { 14236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Create and insert the PHI node for the induction variable in the 14336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // specified loop. 14436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman BasicBlock *Header = L->getHeader(); 145051a950000e21935165db56695e35bade668193bGabor Greif PHINode *PN = PHINode::Create(Ty, "indvar", Header->begin()); 14636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman PN->addIncoming(Constant::getNullValue(Ty), L->getLoopPreheader()); 14736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 14836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman pred_iterator HPI = pred_begin(Header); 14936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman assert(HPI != pred_end(Header) && "Loop with zero preds???"); 15036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (!L->contains(*HPI)) ++HPI; 15136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman assert(HPI != pred_end(Header) && L->contains(*HPI) && 15236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman "No backedge in loop?"); 15336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 15436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Insert a unit add instruction right before the terminator corresponding 15536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // to the back-edge. 15624d6da5fedcf39891f7d8c5b031c01324b3db545Reid Spencer Constant *One = ConstantInt::get(Ty, 1); 1577cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif Instruction *Add = BinaryOperator::CreateAdd(PN, One, "indvar.next", 15836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman (*HPI)->getTerminator()); 15936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 16036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman pred_iterator PI = pred_begin(Header); 16136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (*PI == L->getLoopPreheader()) 16236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman ++PI; 16336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman PN->addIncoming(Add, *PI); 16436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman return PN; 16536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 16636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 16736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Get the canonical induction variable I for this loop. 16836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman Value *I = getOrInsertCanonicalInductionVariable(L, Ty); 16936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 170df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If this is a simple linear addrec, emit it now as a special case. 17136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (S->getNumOperands() == 2) { // {0,+,F} --> i*F 172d19534add90a2a894af61523b830887097bb780bDan Gohman Value *F = expand(S->getOperand(1)); 173df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner 174df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // IF the step is by one, just return the inserted IV. 1756b6b6ef1677fa71b1072c2911b4c1f9524a558c9Zhou Sheng if (ConstantInt *CI = dyn_cast<ConstantInt>(F)) 1764d050d73210d15d8a86ee5967c417ddb5bee4543Reid Spencer if (CI->getValue() == 1) 177df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner return I; 178df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner 179df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If the insert point is directly inside of the loop, emit the multiply at 180df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // the insert point. Otherwise, L is a loop that is a parent of the insert 181df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // point loop. If we can, move the multiply to the outer most loop that it 182df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // is safe to be in. 183df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner Instruction *MulInsertPt = InsertPt; 184df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner Loop *InsertPtLoop = LI.getLoopFor(MulInsertPt->getParent()); 185df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner if (InsertPtLoop != L && InsertPtLoop && 186df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner L->contains(InsertPtLoop->getHeader())) { 1875d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz do { 188df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If we cannot hoist the multiply out of this loop, don't. 189df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner if (!InsertPtLoop->isLoopInvariant(F)) break; 190df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner 1915d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz BasicBlock *InsertPtLoopPH = InsertPtLoop->getLoopPreheader(); 1925d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz 1935d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz // If this loop hasn't got a preheader, we aren't able to hoist the 1945d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz // multiply. 1955d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz if (!InsertPtLoopPH) 1965d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz break; 1975d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz 1985d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz // Otherwise, move the insert point to the preheader. 1995d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz MulInsertPt = InsertPtLoopPH->getTerminator(); 200df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner InsertPtLoop = InsertPtLoop->getParentLoop(); 2015d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz } while (InsertPtLoop != L); 202df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner } 203df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner 2047fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner return InsertBinop(Instruction::Mul, I, F, MulInsertPt); 20536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 20636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 20736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // If this is a chain of recurrences, turn it into a closed form, using the 20836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // folders, then expandCodeFor the closed form. This allows the folders to 20936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // simplify the expression without having to build a bunch of special code 21036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // into this folder. 211246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman SCEVHandle IH = SE.getUnknown(I); // Get I as a "symbolic" SCEV. 21236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 213246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman SCEVHandle V = S->evaluateAtIteration(IH, SE); 214e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; 21536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 216d19534add90a2a894af61523b830887097bb780bDan Gohman return expand(V); 21736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 21896fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 219c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick LewyckyValue *SCEVExpander::visitSMaxExpr(SCEVSMaxExpr *S) { 220c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky Value *LHS = expand(S->getOperand(0)); 221c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky for (unsigned i = 1; i < S->getNumOperands(); ++i) { 222c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky Value *RHS = expand(S->getOperand(i)); 223c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky Value *ICmp = new ICmpInst(ICmpInst::ICMP_SGT, LHS, RHS, "tmp", InsertPt); 224051a950000e21935165db56695e35bade668193bGabor Greif LHS = SelectInst::Create(ICmp, LHS, RHS, "smax", InsertPt); 225c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky } 226c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky return LHS; 227c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky} 228c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky 2293e6307698084e7adfc10b739442ae29742beefd0Nick LewyckyValue *SCEVExpander::visitUMaxExpr(SCEVUMaxExpr *S) { 2303e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky Value *LHS = expand(S->getOperand(0)); 2313e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky for (unsigned i = 1; i < S->getNumOperands(); ++i) { 2323e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky Value *RHS = expand(S->getOperand(i)); 2333e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky Value *ICmp = new ICmpInst(ICmpInst::ICMP_UGT, LHS, RHS, "tmp", InsertPt); 234051a950000e21935165db56695e35bade668193bGabor Greif LHS = SelectInst::Create(ICmp, LHS, RHS, "umax", InsertPt); 2353e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky } 2363e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky return LHS; 2373e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky} 2383e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky 23996fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton KorobeynikovValue *SCEVExpander::expand(SCEV *S) { 24096fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov // Check to see if we already expanded this. 24196fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov std::map<SCEVHandle, Value*>::iterator I = InsertedExpressions.find(S); 24296fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov if (I != InsertedExpressions.end()) 24396fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return I->second; 24496fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 24596fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov Value *V = visit(S); 24696fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov InsertedExpressions[S] = V; 24796fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return V; 24896fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov} 249