ScalarEvolutionExpander.cpp revision c40f17b08774c2dcc5787fd83241e3c64ba82974
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" 1876f600b205606a055ec35e7d3fd1a99602329d67Owen Anderson#include "llvm/LLVMContext.h" 195be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman#include "llvm/Target/TargetData.h" 204d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman#include "llvm/ADT/STLExtras.h" 2136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begemanusing namespace llvm; 2236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 23267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// InsertNoopCastOfTo - Insert a cast of V to the specified type, 24267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// which must be possible with a noop cast, doing what we can to share 25267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// the casts. 26267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertNoopCastOfTo(Value *V, const Type *Ty) { 27267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction::CastOps Op = CastInst::getCastOpcode(V, false, Ty, false); 28267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert((Op == Instruction::BitCast || 29267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::PtrToInt || 30267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::IntToPtr) && 31267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot perform non-noop casts!"); 32267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert(SE.getTypeSizeInBits(V->getType()) == SE.getTypeSizeInBits(Ty) && 33267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot change sizes!"); 34267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 352d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman // Short-circuit unnecessary bitcasts. 36267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (Op == Instruction::BitCast && V->getType() == Ty) 372d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman return V; 382d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 39f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman // Short-circuit unnecessary inttoptr<->ptrtoint casts. 40267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if ((Op == Instruction::PtrToInt || Op == Instruction::IntToPtr) && 4180dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) { 42af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if (CastInst *CI = dyn_cast<CastInst>(V)) 43af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if ((CI->getOpcode() == Instruction::PtrToInt || 44af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman CI->getOpcode() == Instruction::IntToPtr) && 45af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getType()) == 46af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getOperand(0)->getType())) 47af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return CI->getOperand(0); 4880dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 4980dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if ((CE->getOpcode() == Instruction::PtrToInt || 5080dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman CE->getOpcode() == Instruction::IntToPtr) && 5180dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getType()) == 5280dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getOperand(0)->getType())) 5380dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman return CE->getOperand(0); 5480dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman } 55f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman 56ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner // FIXME: keep track of the cast instruction. 57ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 58baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Op, C, Ty); 59ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 60ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Argument *A = dyn_cast<Argument>(V)) { 61ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner // Check to see if there is already a cast! 62ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner for (Value::use_iterator UI = A->use_begin(), E = A->use_end(); 6340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman UI != E; ++UI) 64ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if ((*UI)->getType() == Ty) 653913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (CastInst *CI = dyn_cast<CastInst>(cast<Instruction>(*UI))) 66267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (CI->getOpcode() == Op) { 673913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz // If the cast isn't the first instruction of the function, move it. 6840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (BasicBlock::iterator(CI) != 693913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz A->getParent()->getEntryBlock().begin()) { 7040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Recreate the cast at the beginning of the entry block. 7140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // The old cast is left in place in case it is being used 7240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // as an insert point. 7340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Instruction *NewCI = 74267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman CastInst::Create(Op, V, Ty, "", 7540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman A->getParent()->getEntryBlock().begin()); 7640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman NewCI->takeName(CI); 7740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman CI->replaceAllUsesWith(NewCI); 7840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return NewCI; 793913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz } 803913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz return CI; 81ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 8240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 83267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *I = CastInst::Create(Op, V, Ty, V->getName(), 84cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman A->getParent()->getEntryBlock().begin()); 85cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(I); 86cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 87ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 883913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 89ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner Instruction *I = cast<Instruction>(V); 903913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 91ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner // Check to see if there is already a cast. If there is, use it. 92ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); 93ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner UI != E; ++UI) { 94ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if ((*UI)->getType() == Ty) 953913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (CastInst *CI = dyn_cast<CastInst>(cast<Instruction>(*UI))) 96267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (CI->getOpcode() == Op) { 973913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz BasicBlock::iterator It = I; ++It; 983913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (isa<InvokeInst>(I)) 993913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz It = cast<InvokeInst>(I)->getNormalDest()->begin(); 1003913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz while (isa<PHINode>(It)) ++It; 1013913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (It != BasicBlock::iterator(CI)) { 10240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Recreate the cast at the beginning of the entry block. 10340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // The old cast is left in place in case it is being used 10440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // as an insert point. 105267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *NewCI = CastInst::Create(Op, V, Ty, "", It); 10640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman NewCI->takeName(CI); 10740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman CI->replaceAllUsesWith(NewCI); 10840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return NewCI; 1093913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz } 1103913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz return CI; 111ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 112ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 113ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner BasicBlock::iterator IP = I; ++IP; 114ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(I)) 115ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner IP = II->getNormalDest()->begin(); 116ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner while (isa<PHINode>(IP)) ++IP; 117267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *CI = CastInst::Create(Op, V, Ty, V->getName(), IP); 118cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(CI); 119cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return CI; 120ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner} 121ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 1227fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// InsertBinop - Insert the specified binary operator, doing a small amount 1237fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// of work to avoid inserting an obviously redundant operation. 124267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, 125267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *LHS, Value *RHS) { 1260f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman // Fold a binop with constant operands. 1270f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(LHS)) 1280f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(RHS)) 129baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, CLHS, CRHS); 1300f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman 1317fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner // Do a quick scan to see if we have this binop nearby. If so, reuse it. 1327fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner unsigned ScanLimit = 6; 133267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 134267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 135267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 136267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 1378a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz --IP; 1388a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz for (; ScanLimit; --IP, --ScanLimit) { 1395be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == (unsigned)Opcode && IP->getOperand(0) == LHS && 1405be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(1) == RHS) 1415be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 1428a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (IP == BlockBegin) break; 1438a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz } 1447fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner } 145267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 1468a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // If we haven't found this binop, insert it. 147267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *BO = Builder.CreateBinOp(Opcode, LHS, RHS, "tmp"); 148cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(BO); 149cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return BO; 1507fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner} 1517fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner 1524a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// FactorOutConstant - Test if S is divisible by Factor, using signed 153453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// division. If so, update S with Factor divided out and return true. 1544a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// S need not be evenly divisble if a reasonable remainder can be 1554a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// computed. 156453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// TODO: When ScalarEvolution gets a SCEVSDivExpr, this can be made 157453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// unnecessary; in its place, just signed-divide Ops[i] by the scale and 158453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// check to see if the divide was folded. 1590bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic bool FactorOutConstant(const SCEV *&S, 1600bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *&Remainder, 161c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Factor, 162c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE, 163c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const TargetData *TD) { 164453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Everything is divisible by one. 165c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Factor->isOne()) 166c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 167c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 168c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // x/x == 1. 169c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (S == Factor) { 170c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getIntegerSCEV(1, S->getType()); 171453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 172c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 173453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 174453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // For a Constant, check for a multiple of the given factor. 1754a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S)) { 176c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // 0/x == 0. 177c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (C->isZero()) 178453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 179c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Check for divisibility. 180c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *FC = dyn_cast<SCEVConstant>(Factor)) { 181c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt *CI = 182c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt::get(SE.getContext(), 183c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman C->getValue()->getValue().sdiv( 184c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 185c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the quotient is zero and the remainder is non-zero, reject 186c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the value at this scale. It will be considered for subsequent 187c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // smaller scales. 188c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!CI->isZero()) { 189c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Div = SE.getConstant(CI); 190c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = Div; 191c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder = 192c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(Remainder, 193c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().srem( 194c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue()))); 195c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 196c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 197453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1984a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman } 199453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 200453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In a Mul, check if there is a constant operand which is a multiple 201453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // of the given factor. 202c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S)) { 203c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (TD) { 204c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, the size is known. Check if there is a constant 205c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // operand which is a multiple of the given factor. If so, we can 206c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // factor it. 207c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEVConstant *FC = cast<SCEVConstant>(Factor); 208c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0))) 209c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!C->getValue()->getValue().srem(FC->getValue()->getValue())) { 210c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SmallVectorImpl<const SCEV *> &MOperands = M->getOperands(); 211c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(MOperands.begin(), 212c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman MOperands.end()); 213c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[0] = 214c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().sdiv( 215c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 216c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 217c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 218c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 219c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 220c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Without TargetData, check if Factor can be factored out of any of the 221c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Mul's operands. If so, we can just remove it. 222c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) { 223c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *SOp = M->getOperand(i); 224c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Remainder = SE.getIntegerSCEV(0, SOp->getType()); 225c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (FactorOutConstant(SOp, Remainder, Factor, SE, TD) && 226c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder->isZero()) { 227c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SmallVectorImpl<const SCEV *> &MOperands = M->getOperands(); 228c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(MOperands.begin(), 229c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman MOperands.end()); 230c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[i] = SOp; 231c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 232c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 233c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 234453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 235c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 236c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 237453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 238453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In an AddRec, check if both start and step are divisible. 239453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(S)) { 2400bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Step = A->getStepRecurrence(SE); 2410bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *StepRem = SE.getIntegerSCEV(0, Step->getType()); 242c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Step, StepRem, Factor, SE, TD)) 2434a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2444a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (!StepRem->isZero()) 2454a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2460bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Start = A->getStart(); 247c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Start, Remainder, Factor, SE, TD)) 248453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 249453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman S = SE.getAddRecExpr(Start, Step, A->getLoop()); 250453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 251453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 252453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 253453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 254453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 255453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 256c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SimplifyAddOperands - Sort and simplify a list of add operands. NumAddRecs 257c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// is the number of SCEVAddRecExprs present, which are kept at the end of 258c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// the list. 259c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 260c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SimplifyAddOperands(SmallVectorImpl<const SCEV *> &Ops, 261c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const Type *Ty, 262c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 263c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman unsigned NumAddRecs = 0; 264c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = Ops.size(); i > 0 && isa<SCEVAddRecExpr>(Ops[i-1]); --i) 265c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ++NumAddRecs; 266c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Group Ops into non-addrecs and addrecs. 267c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> NoAddRecs(Ops.begin(), Ops.end() - NumAddRecs); 268c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs(Ops.end() - NumAddRecs, Ops.end()); 269c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Let ScalarEvolution sort and simplify the non-addrecs list. 270c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Sum = NoAddRecs.empty() ? 271c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getIntegerSCEV(0, Ty) : 272c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(NoAddRecs); 273c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If it returned an add, use the operands. Otherwise it simplified 274c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the sum into a single value, so just use that. 275c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Sum)) 276c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops = Add->getOperands(); 277c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman else { 278c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops.clear(); 279c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!Sum->isZero()) 280c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops.push_back(Sum); 281c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 282c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Then append the addrecs. 283c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops.insert(Ops.end(), AddRecs.begin(), AddRecs.end()); 284c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 285c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 286c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SplitAddRecs - Flatten a list of add operands, moving addrec start values 287c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// out to the top level. For example, convert {a + b,+,c} to a, b, {0,+,d}. 288c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// This helps expose more opportunities for folding parts of the expressions 289c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// into GEP indices. 290c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 291c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SplitAddRecs(SmallVectorImpl<const SCEV *> &Ops, 292c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const Type *Ty, 293c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 294c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Find the addrecs. 295c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs; 296c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 297c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) { 298c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Start = A->getStart(); 299c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Start->isZero()) break; 300c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Zero = SE.getIntegerSCEV(0, Ty); 301c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AddRecs.push_back(SE.getAddRecExpr(Zero, 302c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getStepRecurrence(SE), 303c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getLoop())); 304c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Start)) { 305c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Zero; 306c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops.insert(Ops.end(), Add->op_begin(), Add->op_end()); 307c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman e += Add->getNumOperands(); 308c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 309c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Start; 310c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 311c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 312c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!AddRecs.empty()) { 313c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Add the addrecs onto the end of the list. 314c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops.insert(Ops.end(), AddRecs.begin(), AddRecs.end()); 315c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Resort the operand list, moving any constants to the front. 316c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 317c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 318c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 319c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 3205be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman/// expandAddToGEP - Expand a SCEVAddExpr with a pointer type into a GEP 321453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// instead of using ptrtoint+arithmetic+inttoptr. This helps 322c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// BasicAliasAnalysis and other passes analyze the result. 32313c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// 32413c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// Design note: This depends on ScalarEvolution not recognizing inttoptr 32513c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// and ptrtoint operators, as they may introduce pointer arithmetic 32613c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// which may not be safely converted into getelementptr. 327453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 328453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Design note: It might seem desirable for this function to be more 329453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-aware. If some of the indices are loop-invariant while others 330453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// aren't, it might seem desirable to emit multiple GEPs, keeping the 331453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of the overall computation outside the loop. 332453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// However, there are a few reasons this is not done here. Hoisting simple 333453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// arithmetic is a low-level optimization that often isn't very 334453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// important until late in the optimization process. In fact, passes 335453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// like InstructionCombining will combine GEPs, even if it means 336453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// pushing loop-invariant computation down into loops, so even if the 337453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEPs were split here, the work would quickly be undone. The 338453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// LoopStrengthReduction pass, which is usually run quite late (and 339453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// after the last InstructionCombining pass), takes care of hoisting 340453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of expressions, after considering what 341453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// can be folded using target addressing modes. 342453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 3430bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin, 3440bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *const *op_end, 3455be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const PointerType *PTy, 3465be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const Type *Ty, 3475be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *V) { 3485be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const Type *ElTy = PTy->getElementType(); 3495be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman SmallVector<Value *, 4> GepIndices; 3500bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> Ops(op_begin, op_end); 3515be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman bool AnyNonZeroIndices = false; 3525be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 353c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Split AddRecs up into parts as either of the parts may be usable 354c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // without the other. 355c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SplitAddRecs(Ops, Ty, SE); 356c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 3575be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Decend down the pointer's type and attempt to convert the other 3585be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // operands into GEP indices, at each level. The first index in a GEP 3595be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // indexes into the array implied by the pointer operand; the rest of 3605be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the indices index into the element or field type selected by the 3615be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // preceding index. 3625be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (;;) { 363c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *ElSize = SE.getAllocSizeExpr(ElTy); 364c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the scale size is not 0, attempt to factor out a scale for 365c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // array indexing. 3660bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> ScaledOps; 367c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (ElTy->isSized() && !ElSize->isZero()) { 368c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> NewOps; 369c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 3700bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Op = Ops[i]; 371c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Remainder = SE.getIntegerSCEV(0, Ty); 372c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (FactorOutConstant(Op, Remainder, ElSize, SE, SE.TD)) { 373c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Op now has ElSize factored out. 374c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScaledOps.push_back(Op); 375c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!Remainder->isZero()) 376c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewOps.push_back(Remainder); 377c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AnyNonZeroIndices = true; 378c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 379c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // The operand was not divisible, so add it to the list of operands 380c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // we'll scan next iteration. 381c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewOps.push_back(Ops[i]); 3825be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 3835be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 384c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If we made any changes, update Ops. 385c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!ScaledOps.empty()) { 386c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops = NewOps; 387c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 388c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 3895be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 390c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 391c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Record the scaled array index for this level of the type. If 392c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // we didn't find any operands that could be factored, tentatively 393c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // assume that element zero was selected (since the zero offset 394c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // would obviously be folded away). 3955be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *Scaled = ScaledOps.empty() ? 396a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant::getNullValue(Ty) : 3975be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman expandCodeFor(SE.getAddExpr(ScaledOps), Ty); 3985be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman GepIndices.push_back(Scaled); 3995be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4005be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Collect struct field index operands. 401c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const StructType *STy = dyn_cast<StructType>(ElTy)) { 402c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman bool FoundFieldNo = false; 403c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // An empty struct has no fields. 404c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (STy->getNumElements() == 0) break; 405c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (SE.TD) { 406c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, field offsets are known. See if a constant offset 407c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // falls within any of the struct fields. 408c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Ops.empty()) break; 4095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[0])) 4105be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (SE.getTypeSizeInBits(C->getType()) <= 64) { 4115be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const StructLayout &SL = *SE.TD->getStructLayout(STy); 4125be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman uint64_t FullOffset = C->getValue()->getZExtValue(); 4135be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (FullOffset < SL.getSizeInBytes()) { 4145be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(FullOffset); 4151d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson GepIndices.push_back( 4161d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson ConstantInt::get(Type::getInt32Ty(Ty->getContext()), ElIdx)); 4175be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = STy->getTypeAtIndex(ElIdx); 4185be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops[0] = 4196de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman SE.getConstant(Ty, FullOffset - SL.getElementOffset(ElIdx)); 4205be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman AnyNonZeroIndices = true; 421c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 4225be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4235be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 424c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 425c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Without TargetData, just check for a SCEVFieldOffsetExpr of the 426c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // appropriate struct type. 427c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 428c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVFieldOffsetExpr *FO = 429c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman dyn_cast<SCEVFieldOffsetExpr>(Ops[i])) 430c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (FO->getStructType() == STy) { 431c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman unsigned FieldNo = FO->getFieldNo(); 432c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman GepIndices.push_back( 433c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 434c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FieldNo)); 435c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ElTy = STy->getTypeAtIndex(FieldNo); 436c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = SE.getConstant(Ty, 0); 437c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AnyNonZeroIndices = true; 438c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 439c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 440c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4415be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 442c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If no struct field offsets were found, tentatively assume that 443c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // field zero was selected (since the zero offset would obviously 444c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // be folded away). 445c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FoundFieldNo) { 446c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ElTy = STy->getTypeAtIndex(0u); 447c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman GepIndices.push_back( 448c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Constant::getNullValue(Type::getInt32Ty(Ty->getContext()))); 449c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 450c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4515be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 452c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const ArrayType *ATy = dyn_cast<ArrayType>(ElTy)) 4535be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = ATy->getElementType(); 454c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman else 455c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 4565be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4575be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4585be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // If none of the operands were convertable to proper GEP indices, cast 4595be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the base to i8* and do an ugly getelementptr with that. It's still 4605be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // better than ptrtoint+arithmetic+inttoptr at least. 4615be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (!AnyNonZeroIndices) { 462c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Cast the base to i8*. 4635be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, 4641d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson Type::getInt8Ty(Ty->getContext())->getPointerTo(PTy->getAddressSpace())); 465c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 466c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Expand the operands for a plain byte offset. 46792fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *Idx = expandCodeFor(SE.getAddExpr(Ops), Ty); 4685be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4695be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Fold a GEP with constant operands. 4705be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(V)) 4715be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(Idx)) 472baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getGetElementPtr(CLHS, &CRHS, 1); 4735be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4745be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Do a quick scan to see if we have this GEP nearby. If so, reuse it. 4755be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ScanLimit = 6; 476267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 477267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 478267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 479267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 4805be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman --IP; 4815be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (; ScanLimit; --IP, --ScanLimit) { 4825be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == Instruction::GetElementPtr && 4835be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(0) == V && IP->getOperand(1) == Idx) 4845be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 4855be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP == BlockBegin) break; 4865be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4875be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 489c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Emit a GEP. 490c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *GEP = Builder.CreateGEP(V, Idx, "uglygep"); 4915be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman InsertedValues.insert(GEP); 4925be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return GEP; 4935be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4945be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 495d6aa02de1076c801ac41295156a2379637976918Dan Gohman // Insert a pretty getelementptr. Note that this GEP is not marked inbounds, 496d6aa02de1076c801ac41295156a2379637976918Dan Gohman // because ScalarEvolution may have changed the address arithmetic to 497d6aa02de1076c801ac41295156a2379637976918Dan Gohman // compute a value which is beyond the end of the allocated object. 498267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *GEP = Builder.CreateGEP(V, 499267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman GepIndices.begin(), 500267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman GepIndices.end(), 501267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "scevgep"); 5025be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops.push_back(SE.getUnknown(GEP)); 5035be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman InsertedValues.insert(GEP); 5045be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return expand(SE.getAddExpr(Ops)); 5055be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman} 5065be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 507890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { 508af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 509e24fa64d52330626553298f56ba5aa702624c282Dan Gohman Value *V = expand(S->getOperand(S->getNumOperands()-1)); 5105be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 511453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the 512453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // comments on expandAddToGEP for details. 513c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const PointerType *PTy = dyn_cast<PointerType>(V->getType())) { 514c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SmallVectorImpl<const SCEV *> &Ops = S->getOperands(); 515c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return expandAddToGEP(&Ops[0], &Ops[Ops.size() - 1], PTy, Ty, V); 516c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 5175be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 518af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman V = InsertNoopCastOfTo(V, Ty); 519e24fa64d52330626553298f56ba5aa702624c282Dan Gohman 520e24fa64d52330626553298f56ba5aa702624c282Dan Gohman // Emit a bunch of add instructions 5212d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 52292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *W = expandCodeFor(S->getOperand(i), Ty); 523267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman V = InsertBinop(Instruction::Add, V, W); 5242d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 525e24fa64d52330626553298f56ba5aa702624c282Dan Gohman return V; 526e24fa64d52330626553298f56ba5aa702624c282Dan Gohman} 5275be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 528890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) { 529af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 53036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman int FirstOp = 0; // Set if we should emit a subtract. 531890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getOperand(0))) 53236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (SC->getValue()->isAllOnesValue()) 53336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman FirstOp = 1; 53436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 53536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman int i = S->getNumOperands()-2; 53692fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(i+1), Ty); 53736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 53836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Emit a bunch of multiply instructions 5392d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman for (; i >= FirstOp; --i) { 54092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *W = expandCodeFor(S->getOperand(i), Ty); 541267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman V = InsertBinop(Instruction::Mul, V, W); 5422d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 5432d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 54436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // -1 * ... ---> 0 - ... 54536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (FirstOp == 1) 546a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson V = InsertBinop(Instruction::Sub, Constant::getNullValue(Ty), V); 54736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman return V; 54836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 54936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 550890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) { 551af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 5522d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 55392fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *LHS = expandCodeFor(S->getLHS(), Ty); 554890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getRHS())) { 5556177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky const APInt &RHS = SC->getValue()->getValue(); 5566177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky if (RHS.isPowerOf2()) 5576177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky return InsertBinop(Instruction::LShr, LHS, 558eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson ConstantInt::get(Ty, RHS.logBase2())); 5596177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky } 5606177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 56192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getRHS(), Ty); 562267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman return InsertBinop(Instruction::UDiv, LHS, RHS); 5636177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky} 5646177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 565453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Move parts of Base into Rest to leave Base with the minimal 566453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// expression that provides a pointer operand suitable for a 567453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEP expansion. 5680bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic void ExposePointerBase(const SCEV *&Base, const SCEV *&Rest, 569453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ScalarEvolution &SE) { 570453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Base)) { 571453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getStart(); 572453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(Rest, 573453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman SE.getAddRecExpr(SE.getIntegerSCEV(0, A->getType()), 574453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getStepRecurrence(SE), 575453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getLoop())); 576453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 577453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(Base)) { 578453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getOperand(A->getNumOperands()-1); 5790bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> NewAddOps(A->op_begin(), A->op_end()); 580453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman NewAddOps.back() = Rest; 581453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(NewAddOps); 582453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ExposePointerBase(Base, Rest, SE); 583453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 584453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 585453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 586890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { 587af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 58836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Loop *L = S->getLoop(); 58936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 5904d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // First check for an existing canonical IV in a suitable type. 5914d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman PHINode *CanonicalIV = 0; 5924d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (PHINode *PN = L->getCanonicalInductionVariable()) 5934d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (SE.isSCEVable(PN->getType()) && 5944d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman isa<IntegerType>(SE.getEffectiveSCEVType(PN->getType())) && 5954d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty)) 5964d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV = PN; 5974d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 5984d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Rewrite an AddRec in terms of the canonical induction variable, if 5994d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // its type is more narrow. 6004d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (CanonicalIV && 6014d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(CanonicalIV->getType()) > 6024d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(Ty)) { 6035001c21712f2e52fd6254461b2b2edb9a5823d23Dan Gohman const SCEV *Start = SE.getAnyExtendExpr(S->getStart(), 6045001c21712f2e52fd6254461b2b2edb9a5823d23Dan Gohman CanonicalIV->getType()); 6055001c21712f2e52fd6254461b2b2edb9a5823d23Dan Gohman const SCEV *Step = SE.getAnyExtendExpr(S->getStepRecurrence(SE), 6064d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV->getType()); 6074d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman Value *V = expand(SE.getAddRecExpr(Start, Step, S->getLoop())); 608267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 609267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 6104d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman BasicBlock::iterator NewInsertPt = 6114d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman next(BasicBlock::iterator(cast<Instruction>(V))); 6124d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman while (isa<PHINode>(NewInsertPt)) ++NewInsertPt; 6134d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), 0, 6144d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewInsertPt); 615267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(SaveInsertBB, SaveInsertPt); 6164d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman return V; 6174d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman } 6184d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 61936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {X,+,F} --> X + {0,+,F} 620cfeb6a450632f2a6cd05302633c8c2b8c90cfdfdDan Gohman if (!S->getStart()->isZero()) { 6210bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SmallVectorImpl<const SCEV *> &SOperands = S->getOperands(); 6220bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 4> NewOps(SOperands.begin(), SOperands.end()); 623246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman NewOps[0] = SE.getIntegerSCEV(0, Ty); 6240bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Rest = SE.getAddRecExpr(NewOps, L); 625453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 626453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the 627453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // comments on expandAddToGEP for details. 628c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Base = S->getStart(); 629c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *RestArray[1] = { Rest }; 630c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Dig into the expression to find the pointer base for a GEP. 631c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ExposePointerBase(Base, RestArray[0], SE); 632c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If we found a pointer, expand the AddRec with a GEP. 633c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const PointerType *PTy = dyn_cast<PointerType>(Base->getType())) { 634c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Make sure the Base isn't something exotic, such as a multiplied 635c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // or divided pointer value. In those cases, the result type isn't 636c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // actually a pointer type. 637c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!isa<SCEVMulExpr>(Base) && !isa<SCEVUDivExpr>(Base)) { 638c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *StartV = expand(Base); 639c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman assert(StartV->getType() == PTy && "Pointer type mismatch for GEP!"); 640c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return expandAddToGEP(RestArray, RestArray+1, PTy, Ty, StartV); 641453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 642453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 643453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 64440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Just do a normal add. Pre-expand the operands to suppress folding. 64540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return expand(SE.getAddExpr(SE.getUnknown(expand(S->getStart())), 64640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getUnknown(expand(Rest)))); 64736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 64836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 64936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {0,+,1} --> Insert a canonical induction variable into the loop! 65017f1972c770dc18f5c7c3c95776b4d62ae9e121dDan Gohman if (S->isAffine() && 651246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman S->getOperand(1) == SE.getIntegerSCEV(1, Ty)) { 6524d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // If there's a canonical IV, just use it. 6534d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (CanonicalIV) { 6544d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) && 6554d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman "IVs with types different from the canonical IV should " 6564d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman "already have been handled!"); 6574d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman return CanonicalIV; 6584d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman } 6594d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 66036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Create and insert the PHI node for the induction variable in the 66136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // specified loop. 66236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman BasicBlock *Header = L->getHeader(); 663267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 664051a950000e21935165db56695e35bade668193bGabor Greif PHINode *PN = PHINode::Create(Ty, "indvar", Header->begin()); 665cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(PN); 666a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson PN->addIncoming(Constant::getNullValue(Ty), Preheader); 66736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 66836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman pred_iterator HPI = pred_begin(Header); 66936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman assert(HPI != pred_end(Header) && "Loop with zero preds???"); 67036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (!L->contains(*HPI)) ++HPI; 67136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman assert(HPI != pred_end(Header) && L->contains(*HPI) && 67236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman "No backedge in loop?"); 67336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 67436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Insert a unit add instruction right before the terminator corresponding 67536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // to the back-edge. 676eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Constant *One = ConstantInt::get(Ty, 1); 6777cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif Instruction *Add = BinaryOperator::CreateAdd(PN, One, "indvar.next", 67836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman (*HPI)->getTerminator()); 679cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(Add); 68036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 68136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman pred_iterator PI = pred_begin(Header); 682267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (*PI == Preheader) 68336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman ++PI; 68436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman PN->addIncoming(Add, *PI); 68536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman return PN; 68636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 68736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 6884d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // {0,+,F} --> {0,+,1} * F 68936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Get the canonical induction variable I for this loop. 6904d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman Value *I = CanonicalIV ? 6914d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV : 6924d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman getOrInsertCanonicalInductionVariable(L, Ty); 69336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 694df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If this is a simple linear addrec, emit it now as a special case. 69540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (S->isAffine()) // {0,+,F} --> i*F 69640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return 69740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman expand(SE.getTruncateOrNoop( 69840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getMulExpr(SE.getUnknown(I), 69940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getNoopOrAnyExtend(S->getOperand(1), 70040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman I->getType())), 70140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Ty)); 70236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 70336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // If this is a chain of recurrences, turn it into a closed form, using the 70436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // folders, then expandCodeFor the closed form. This allows the folders to 70536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // simplify the expression without having to build a bunch of special code 70636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // into this folder. 7070bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *IH = SE.getUnknown(I); // Get I as a "symbolic" SCEV. 70836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 7094d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Promote S up to the canonical IV type, if the cast is foldable. 7100bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *NewS = S; 7110bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Ext = SE.getNoopOrAnyExtend(S, I->getType()); 7124d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (isa<SCEVAddRecExpr>(Ext)) 7134d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewS = Ext; 7144d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 7150bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE); 716e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; 71736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 7184d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Truncate the result down to the original type, if needed. 7190bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *T = SE.getTruncateOrNoop(V, Ty); 720469f3cdc13851914f3a766cbd8f701cf8431cacaDan Gohman return expand(T); 72136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 72296fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 723890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitTruncateExpr(const SCEVTruncateExpr *S) { 724af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 72592fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 72692fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 727267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateTrunc(V, Ty, "tmp"); 728cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(I); 729cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 73011f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 73111f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 732890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitZeroExtendExpr(const SCEVZeroExtendExpr *S) { 733af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 73492fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 73592fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 736267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateZExt(V, Ty, "tmp"); 737cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(I); 738cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 73911f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 74011f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 741890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) { 742af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 74392fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 74492fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 745267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateSExt(V, Ty, "tmp"); 746cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(I); 747cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 74811f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 74911f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 750890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { 7510196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 7520196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman const Type *Ty = LHS->getType(); 7530196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 7540196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 7550196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 7560196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 7570196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 7580196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 7590196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 76092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 761267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *ICmp = Builder.CreateICmpSGT(LHS, RHS, "tmp"); 762cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(ICmp); 763267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "smax"); 764cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(Sel); 765cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 766c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky } 7670196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 7680196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 7690196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 7700196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 771c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky return LHS; 772c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky} 773c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky 774890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { 7750196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 7760196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman const Type *Ty = LHS->getType(); 7770196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 7780196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 7790196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 7800196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 7810196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 7820196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 7830196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 78492fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 785267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *ICmp = Builder.CreateICmpUGT(LHS, RHS, "tmp"); 786cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(ICmp); 787267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "umax"); 788cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman InsertedValues.insert(Sel); 789cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 7903e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky } 7910196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 7920196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 7930196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 7940196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 7953e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky return LHS; 7963e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky} 7973e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky 798c40f17b08774c2dcc5787fd83241e3c64ba82974Dan GohmanValue *SCEVExpander::visitFieldOffsetExpr(const SCEVFieldOffsetExpr *S) { 799c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return ConstantExpr::getOffsetOf(S->getStructType(), S->getFieldNo()); 800c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 801c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 802c40f17b08774c2dcc5787fd83241e3c64ba82974Dan GohmanValue *SCEVExpander::visitAllocSizeExpr(const SCEVAllocSizeExpr *S) { 803c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return ConstantExpr::getSizeOf(S->getAllocType()); 804c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 805c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 8060bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandCodeFor(const SCEV *SH, const Type *Ty) { 80711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman // Expand the code for this SCEV. 8082d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *V = expand(SH); 8095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Ty) { 8105be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman assert(SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(SH->getType()) && 8115be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman "non-trivial casts should be done with the SCEVs directly!"); 8125be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, Ty); 8135be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 8145be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return V; 81511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 81611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 817890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::expand(const SCEV *S) { 81840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Compute an insertion point for this SCEV object. Hoist the instructions 81940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // as far out in the loop nest as possible. 820267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *InsertPt = Builder.GetInsertPoint(); 821267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman for (Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock()); ; 82240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman L = L->getParentLoop()) 82340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (S->isLoopInvariant(L)) { 82440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (!L) break; 82540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (BasicBlock *Preheader = L->getLoopPreheader()) 82640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = Preheader->getTerminator(); 82740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } else { 82840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // If the SCEV is computable at this level, insert it into the header 82940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // after the PHIs (and after any other instructions that we've inserted 83040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // there) so that it is guaranteed to dominate any user inside the loop. 83140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (L && S->hasComputableLoopEvolution(L)) 83240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = L->getHeader()->getFirstNonPHI(); 833267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman while (isInsertedInstruction(InsertPt)) 834267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman InsertPt = next(BasicBlock::iterator(InsertPt)); 83540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman break; 83640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } 83740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 838667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Check to see if we already expanded this here. 839667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman std::map<std::pair<const SCEV *, Instruction *>, 840667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman AssertingVH<Value> >::iterator I = 841667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman InsertedExpressions.find(std::make_pair(S, InsertPt)); 842267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (I != InsertedExpressions.end()) 843667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman return I->second; 844267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 845267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 846267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 847267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(InsertPt->getParent(), InsertPt); 848667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 849667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Expand the expression into instructions. 85096fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov Value *V = visit(S); 85140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 852667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Remember the expanded value for this SCEV at this location. 853667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman InsertedExpressions[std::make_pair(S, InsertPt)] = V; 854667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 855267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(SaveInsertBB, SaveInsertPt); 85696fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return V; 85796fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov} 8581d09de3eca23267855e28297fcb40de3632ea47bDan Gohman 8591d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// getOrInsertCanonicalInductionVariable - This method returns the 8601d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// canonical induction variable of the specified type for the specified 8611d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// loop (inserting one if there is none). A canonical induction variable 8621d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// starts at zero and steps by one on each iteration. 8631d09de3eca23267855e28297fcb40de3632ea47bDan GohmanValue * 8641d09de3eca23267855e28297fcb40de3632ea47bDan GohmanSCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L, 8651d09de3eca23267855e28297fcb40de3632ea47bDan Gohman const Type *Ty) { 8661d09de3eca23267855e28297fcb40de3632ea47bDan Gohman assert(Ty->isInteger() && "Can only insert integer induction variables!"); 8670bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *H = SE.getAddRecExpr(SE.getIntegerSCEV(0, Ty), 86840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getIntegerSCEV(1, Ty), L); 869267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 870267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 87140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Value *V = expandCodeFor(H, 0, L->getHeader()->begin()); 872267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (SaveInsertBB) 873267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(SaveInsertBB, SaveInsertPt); 87440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return V; 8751d09de3eca23267855e28297fcb40de3632ea47bDan Gohman} 876