ScalarEvolutionExpander.cpp revision 485c43fc478d5e16c55e14cb2586b56cc1c4c91f
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" 188d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen#include "llvm/IntrinsicInst.h" 1976f600b205606a055ec35e7d3fd1a99602329d67Owen Anderson#include "llvm/LLVMContext.h" 205be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman#include "llvm/Target/TargetData.h" 214d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman#include "llvm/ADT/STLExtras.h" 2236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begemanusing namespace llvm; 2336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 24485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// ReuseOrCreateCast - Arange for there to be a cast of V to Ty at IP, 25485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// reusing an existing cast if a suitable one exists, moving an existing 26485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// cast if a suitable one exists but isn't in the right place, or 27485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// or creating a new one. 28485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan GohmanValue *SCEVExpander::ReuseOrCreateCast(Value *V, const Type *Ty, 29485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction::CastOps Op, 30485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP) { 31485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Check to see if there is already a cast! 32485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); 33485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman UI != E; ++UI) 34485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if ((*UI)->getType() == Ty) 35485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (CastInst *CI = dyn_cast<CastInst>(cast<Instruction>(*UI))) 36485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (CI->getOpcode() == Op) { 37485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // If the cast isn't where we want it, fix it. 38485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (BasicBlock::iterator(CI) != IP) { 39485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast, and leave the old cast in place in case 40485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // it is being used as an insert point. Clear its operand 41485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // so that it doesn't hold anything live. 42485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *NewCI = CastInst::Create(Op, V, Ty, "", IP); 43485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman NewCI->takeName(CI); 44485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->replaceAllUsesWith(NewCI); 45485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->setOperand(0, UndefValue::get(V->getType())); 46485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(NewCI); 47485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return NewCI; 48485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 49485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return CI; 50485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 51485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 52485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast. 53485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *I = CastInst::Create(Op, V, Ty, V->getName(), IP); 54485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(I); 55485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return I; 56485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman} 57485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 58267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// InsertNoopCastOfTo - Insert a cast of V to the specified type, 59267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// which must be possible with a noop cast, doing what we can to share 60267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// the casts. 61267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertNoopCastOfTo(Value *V, const Type *Ty) { 62267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction::CastOps Op = CastInst::getCastOpcode(V, false, Ty, false); 63267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert((Op == Instruction::BitCast || 64267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::PtrToInt || 65267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::IntToPtr) && 66267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot perform non-noop casts!"); 67267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert(SE.getTypeSizeInBits(V->getType()) == SE.getTypeSizeInBits(Ty) && 68267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot change sizes!"); 69267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 702d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman // Short-circuit unnecessary bitcasts. 71267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (Op == Instruction::BitCast && V->getType() == Ty) 722d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman return V; 732d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 74f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman // Short-circuit unnecessary inttoptr<->ptrtoint casts. 75267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if ((Op == Instruction::PtrToInt || Op == Instruction::IntToPtr) && 7680dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) { 77af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if (CastInst *CI = dyn_cast<CastInst>(V)) 78af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if ((CI->getOpcode() == Instruction::PtrToInt || 79af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman CI->getOpcode() == Instruction::IntToPtr) && 80af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getType()) == 81af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getOperand(0)->getType())) 82af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return CI->getOperand(0); 8380dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 8480dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if ((CE->getOpcode() == Instruction::PtrToInt || 8580dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman CE->getOpcode() == Instruction::IntToPtr) && 8680dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getType()) == 8780dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getOperand(0)->getType())) 8880dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman return CE->getOperand(0); 8980dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman } 90f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman 91485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Fold a cast of a constant. 92ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 93baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Op, C, Ty); 944c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman 95485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the argument at the beginning of the entry block, after 96485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // any bitcasts of other arguments. 97ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Argument *A = dyn_cast<Argument>(V)) { 98485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP = A->getParent()->getEntryBlock().begin(); 99485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman while ((isa<BitCastInst>(IP) && 100485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman isa<Argument>(cast<BitCastInst>(IP)->getOperand(0)) && 101485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman cast<BitCastInst>(IP)->getOperand(0) != A) || 102485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman isa<DbgInfoIntrinsic>(IP)) 103485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman ++IP; 104485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(A, Ty, Op, IP); 105ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 1063913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 107485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the instruction immediately after the instruction. 108ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner Instruction *I = cast<Instruction>(V); 109ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner BasicBlock::iterator IP = I; ++IP; 110ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(I)) 111ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner IP = II->getNormalDest()->begin(); 11208f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach while (isa<PHINode>(IP) || isa<DbgInfoIntrinsic>(IP)) ++IP; 113485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(I, Ty, Op, IP); 114ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner} 115ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 1167fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// InsertBinop - Insert the specified binary operator, doing a small amount 1177fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// of work to avoid inserting an obviously redundant operation. 118267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, 119267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *LHS, Value *RHS) { 1200f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman // Fold a binop with constant operands. 1210f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(LHS)) 1220f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(RHS)) 123baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, CLHS, CRHS); 1240f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman 1257fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner // Do a quick scan to see if we have this binop nearby. If so, reuse it. 1267fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner unsigned ScanLimit = 6; 127267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 128267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 129267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 130267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 1318a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz --IP; 1328a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz for (; ScanLimit; --IP, --ScanLimit) { 1338d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 1348d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 1358d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 1368d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 1375be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == (unsigned)Opcode && IP->getOperand(0) == LHS && 1385be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(1) == RHS) 1395be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 1408a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (IP == BlockBegin) break; 1418a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz } 1427fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner } 143267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 144087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 145087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 146087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 147087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 148087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 149087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 150087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(LHS) || !L->isLoopInvariant(RHS)) break; 151087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 152087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 153087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 154087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 155087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 156087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 157087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 1588a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // If we haven't found this binop, insert it. 159267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *BO = Builder.CreateBinOp(Opcode, LHS, RHS, "tmp"); 160a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(BO); 161087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 162087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 163087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 164087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 165087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 166cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return BO; 1677fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner} 1687fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner 1694a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// FactorOutConstant - Test if S is divisible by Factor, using signed 170453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// division. If so, update S with Factor divided out and return true. 1713f46a3abeedba8d517b4182de34c821d752db058Dan Gohman/// S need not be evenly divisible if a reasonable remainder can be 1724a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// computed. 173453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// TODO: When ScalarEvolution gets a SCEVSDivExpr, this can be made 174453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// unnecessary; in its place, just signed-divide Ops[i] by the scale and 175453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// check to see if the divide was folded. 1760bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic bool FactorOutConstant(const SCEV *&S, 1770bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *&Remainder, 178c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Factor, 179c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE, 180c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const TargetData *TD) { 181453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Everything is divisible by one. 182c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Factor->isOne()) 183c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 184c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 185c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // x/x == 1. 186c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (S == Factor) { 187deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman S = SE.getConstant(S->getType(), 1); 188453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 189c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 190453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 191453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // For a Constant, check for a multiple of the given factor. 1924a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S)) { 193c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // 0/x == 0. 194c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (C->isZero()) 195453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 196c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Check for divisibility. 197c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *FC = dyn_cast<SCEVConstant>(Factor)) { 198c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt *CI = 199c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt::get(SE.getContext(), 200c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman C->getValue()->getValue().sdiv( 201c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 202c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the quotient is zero and the remainder is non-zero, reject 203c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the value at this scale. It will be considered for subsequent 204c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // smaller scales. 205c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!CI->isZero()) { 206c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Div = SE.getConstant(CI); 207c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = Div; 208c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder = 209c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(Remainder, 210c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().srem( 211c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue()))); 212c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 213c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 214453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 2154a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman } 216453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 217453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In a Mul, check if there is a constant operand which is a multiple 218453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // of the given factor. 219c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S)) { 220c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (TD) { 221c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, the size is known. Check if there is a constant 222c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // operand which is a multiple of the given factor. If so, we can 223c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // factor it. 224c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEVConstant *FC = cast<SCEVConstant>(Factor); 225c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0))) 226c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!C->getValue()->getValue().srem(FC->getValue()->getValue())) { 227f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 228c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[0] = 229c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().sdiv( 230c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 231c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 232c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 233c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 234c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 235c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Without TargetData, check if Factor can be factored out of any of the 236c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Mul's operands. If so, we can just remove it. 237c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) { 238c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *SOp = M->getOperand(i); 239deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(SOp->getType(), 0); 240c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (FactorOutConstant(SOp, Remainder, Factor, SE, TD) && 241c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder->isZero()) { 242f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 243c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[i] = SOp; 244c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 245c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 246c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 247453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 248c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 249c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 250453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 251453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In an AddRec, check if both start and step are divisible. 252453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(S)) { 2530bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Step = A->getStepRecurrence(SE); 254deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *StepRem = SE.getConstant(Step->getType(), 0); 255c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Step, StepRem, Factor, SE, TD)) 2564a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2574a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (!StepRem->isZero()) 2584a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2590bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Start = A->getStart(); 260c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Start, Remainder, Factor, SE, TD)) 261453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 262453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman S = SE.getAddRecExpr(Start, Step, A->getLoop()); 263453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 264453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 265453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 266453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 267453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 268453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 269c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SimplifyAddOperands - Sort and simplify a list of add operands. NumAddRecs 270c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// is the number of SCEVAddRecExprs present, which are kept at the end of 271c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// the list. 272c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 273c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SimplifyAddOperands(SmallVectorImpl<const SCEV *> &Ops, 274c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const Type *Ty, 275c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 276c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman unsigned NumAddRecs = 0; 277c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = Ops.size(); i > 0 && isa<SCEVAddRecExpr>(Ops[i-1]); --i) 278c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ++NumAddRecs; 279c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Group Ops into non-addrecs and addrecs. 280c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> NoAddRecs(Ops.begin(), Ops.end() - NumAddRecs); 281c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs(Ops.end() - NumAddRecs, Ops.end()); 282c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Let ScalarEvolution sort and simplify the non-addrecs list. 283c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Sum = NoAddRecs.empty() ? 284deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getConstant(Ty, 0) : 285c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(NoAddRecs); 286c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If it returned an add, use the operands. Otherwise it simplified 287c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the sum into a single value, so just use that. 288f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.clear(); 289c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Sum)) 290f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.insert(Ops.end(), Add->op_begin(), Add->op_end()); 291f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman else if (!Sum->isZero()) 292f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.push_back(Sum); 293c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Then append the addrecs. 294c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops.insert(Ops.end(), AddRecs.begin(), AddRecs.end()); 295c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 296c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 297c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SplitAddRecs - Flatten a list of add operands, moving addrec start values 298c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// out to the top level. For example, convert {a + b,+,c} to a, b, {0,+,d}. 299c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// This helps expose more opportunities for folding parts of the expressions 300c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// into GEP indices. 301c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 302c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SplitAddRecs(SmallVectorImpl<const SCEV *> &Ops, 303c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const Type *Ty, 304c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 305c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Find the addrecs. 306c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs; 307c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 308c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) { 309c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Start = A->getStart(); 310c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Start->isZero()) break; 311deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Zero = SE.getConstant(Ty, 0); 312c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AddRecs.push_back(SE.getAddRecExpr(Zero, 313c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getStepRecurrence(SE), 314c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getLoop())); 315c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Start)) { 316c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Zero; 317c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops.insert(Ops.end(), Add->op_begin(), Add->op_end()); 318c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman e += Add->getNumOperands(); 319c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 320c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Start; 321c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 322c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 323c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!AddRecs.empty()) { 324c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Add the addrecs onto the end of the list. 325c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops.insert(Ops.end(), AddRecs.begin(), AddRecs.end()); 326c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Resort the operand list, moving any constants to the front. 327c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 328c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 329c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 330c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 3314c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// expandAddToGEP - Expand an addition expression with a pointer type into 3324c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps 3334c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// BasicAliasAnalysis and other passes analyze the result. See the rules 3344c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for getelementptr vs. inttoptr in 3354c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// http://llvm.org/docs/LangRef.html#pointeraliasing 3364c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for details. 33713c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// 3383abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman/// Design note: The correctness of using getelementptr here depends on 3394c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as 3404c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// they may introduce pointer arithmetic which may not be safely converted 3414c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// into getelementptr. 342453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 343453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Design note: It might seem desirable for this function to be more 344453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-aware. If some of the indices are loop-invariant while others 345453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// aren't, it might seem desirable to emit multiple GEPs, keeping the 346453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of the overall computation outside the loop. 347453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// However, there are a few reasons this is not done here. Hoisting simple 348453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// arithmetic is a low-level optimization that often isn't very 349453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// important until late in the optimization process. In fact, passes 350453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// like InstructionCombining will combine GEPs, even if it means 351453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// pushing loop-invariant computation down into loops, so even if the 352453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEPs were split here, the work would quickly be undone. The 353453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// LoopStrengthReduction pass, which is usually run quite late (and 354453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// after the last InstructionCombining pass), takes care of hoisting 355453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of expressions, after considering what 356453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// can be folded using target addressing modes. 357453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 3580bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin, 3590bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *const *op_end, 3605be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const PointerType *PTy, 3615be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const Type *Ty, 3625be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *V) { 3635be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const Type *ElTy = PTy->getElementType(); 3645be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman SmallVector<Value *, 4> GepIndices; 3650bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> Ops(op_begin, op_end); 3665be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman bool AnyNonZeroIndices = false; 3675be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 368c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Split AddRecs up into parts as either of the parts may be usable 369c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // without the other. 370c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SplitAddRecs(Ops, Ty, SE); 371c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 372eb35699e642f2c021f04154bdb4bd90a1afb3baaBob Wilson // Descend down the pointer's type and attempt to convert the other 3735be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // operands into GEP indices, at each level. The first index in a GEP 3745be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // indexes into the array implied by the pointer operand; the rest of 3755be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the indices index into the element or field type selected by the 3765be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // preceding index. 3775be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (;;) { 378c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the scale size is not 0, attempt to factor out a scale for 379c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // array indexing. 3800bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> ScaledOps; 381150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (ElTy->isSized()) { 3824f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const SCEV *ElSize = SE.getSizeOfExpr(ElTy); 383150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ElSize->isZero()) { 384150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SmallVector<const SCEV *, 8> NewOps; 385150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 386150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman const SCEV *Op = Ops[i]; 387deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(Ty, 0); 388150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (FactorOutConstant(Op, Remainder, ElSize, SE, SE.TD)) { 389150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // Op now has ElSize factored out. 390150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman ScaledOps.push_back(Op); 391150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!Remainder->isZero()) 392150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Remainder); 393150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman AnyNonZeroIndices = true; 394150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } else { 395150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // The operand was not divisible, so add it to the list of operands 396150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // we'll scan next iteration. 397150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Ops[i]); 398150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 399150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 400150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // If we made any changes, update Ops. 401150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ScaledOps.empty()) { 402150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman Ops = NewOps; 403150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 4045be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 405c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4065be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 407c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 408c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Record the scaled array index for this level of the type. If 409c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // we didn't find any operands that could be factored, tentatively 410c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // assume that element zero was selected (since the zero offset 411c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // would obviously be folded away). 4125be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *Scaled = ScaledOps.empty() ? 413a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant::getNullValue(Ty) : 4145be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman expandCodeFor(SE.getAddExpr(ScaledOps), Ty); 4155be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman GepIndices.push_back(Scaled); 4165be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4175be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Collect struct field index operands. 418c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const StructType *STy = dyn_cast<StructType>(ElTy)) { 419c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman bool FoundFieldNo = false; 420c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // An empty struct has no fields. 421c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (STy->getNumElements() == 0) break; 422c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (SE.TD) { 423c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, field offsets are known. See if a constant offset 424c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // falls within any of the struct fields. 425c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Ops.empty()) break; 4265be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[0])) 4275be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (SE.getTypeSizeInBits(C->getType()) <= 64) { 4285be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const StructLayout &SL = *SE.TD->getStructLayout(STy); 4295be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman uint64_t FullOffset = C->getValue()->getZExtValue(); 4305be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (FullOffset < SL.getSizeInBytes()) { 4315be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(FullOffset); 4321d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson GepIndices.push_back( 4331d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson ConstantInt::get(Type::getInt32Ty(Ty->getContext()), ElIdx)); 4345be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = STy->getTypeAtIndex(ElIdx); 4355be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops[0] = 4366de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman SE.getConstant(Ty, FullOffset - SL.getElementOffset(ElIdx)); 4375be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman AnyNonZeroIndices = true; 438c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 4395be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4405be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 441c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 4420f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman // Without TargetData, just check for an offsetof expression of the 443c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // appropriate struct type. 444c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 4450f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Ops[i])) { 4464f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const Type *CTy; 4470f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman Constant *FieldNo; 4484f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (U->isOffsetOf(CTy, FieldNo) && CTy == STy) { 4490f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman GepIndices.push_back(FieldNo); 4500f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman ElTy = 4510f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman STy->getTypeAtIndex(cast<ConstantInt>(FieldNo)->getZExtValue()); 452c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = SE.getConstant(Ty, 0); 453c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AnyNonZeroIndices = true; 454c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 455c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 456c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4570f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman } 4585be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 459c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If no struct field offsets were found, tentatively assume that 460c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // field zero was selected (since the zero offset would obviously 461c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // be folded away). 462c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FoundFieldNo) { 463c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ElTy = STy->getTypeAtIndex(0u); 464c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman GepIndices.push_back( 465c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Constant::getNullValue(Type::getInt32Ty(Ty->getContext()))); 466c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 467c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4685be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 469c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const ArrayType *ATy = dyn_cast<ArrayType>(ElTy)) 4705be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = ATy->getElementType(); 471c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman else 472c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 4735be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4745be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4753f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If none of the operands were convertible to proper GEP indices, cast 4765be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the base to i8* and do an ugly getelementptr with that. It's still 4775be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // better than ptrtoint+arithmetic+inttoptr at least. 4785be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (!AnyNonZeroIndices) { 479c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Cast the base to i8*. 4805be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, 481ac53a0b272452013124bfc70480aea5e41b60f40Duncan Sands Type::getInt8PtrTy(Ty->getContext(), PTy->getAddressSpace())); 482c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 483c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Expand the operands for a plain byte offset. 48492fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *Idx = expandCodeFor(SE.getAddExpr(Ops), Ty); 4855be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4865be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Fold a GEP with constant operands. 4875be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(V)) 4885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(Idx)) 489baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getGetElementPtr(CLHS, &CRHS, 1); 4905be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4915be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Do a quick scan to see if we have this GEP nearby. If so, reuse it. 4925be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ScanLimit = 6; 493267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 494267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 495267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 496267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 4975be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman --IP; 4985be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (; ScanLimit; --IP, --ScanLimit) { 4998d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 5008d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 5018d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 5028d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 5035be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == Instruction::GetElementPtr && 5045be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(0) == V && IP->getOperand(1) == Idx) 5055be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 5065be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP == BlockBegin) break; 5075be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5085be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 510087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 511087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 512087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 513087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 514087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 515087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 516087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V) || !L->isLoopInvariant(Idx)) break; 517087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 518087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 519087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 520087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 521087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 522087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 523087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 524c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Emit a GEP. 525c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *GEP = Builder.CreateGEP(V, Idx, "uglygep"); 526a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 527087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 528087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 529087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 530087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 531087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5325be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return GEP; 5335be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5345be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 535087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 536087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 537087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 538087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 539087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 540087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 541087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V)) break; 542087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 543087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool AnyIndexNotLoopInvariant = false; 544087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<Value *>::const_iterator I = GepIndices.begin(), 545087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E = GepIndices.end(); I != E; ++I) 546087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(*I)) { 547087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman AnyIndexNotLoopInvariant = true; 548087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 549087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 550087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (AnyIndexNotLoopInvariant) 551087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 552087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 553087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 554087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 555087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 556087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 557087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 558087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 559087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 560d6aa02de1076c801ac41295156a2379637976918Dan Gohman // Insert a pretty getelementptr. Note that this GEP is not marked inbounds, 561d6aa02de1076c801ac41295156a2379637976918Dan Gohman // because ScalarEvolution may have changed the address arithmetic to 562d6aa02de1076c801ac41295156a2379637976918Dan Gohman // compute a value which is beyond the end of the allocated object. 563a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Casted = V; 564a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (V->getType() != PTy) 565a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Casted = InsertNoopCastOfTo(Casted, PTy); 566a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *GEP = Builder.CreateGEP(Casted, 567267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman GepIndices.begin(), 568267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman GepIndices.end(), 569267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "scevgep"); 5705be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops.push_back(SE.getUnknown(GEP)); 571a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 572087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 573087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 574087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 575087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 576087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5775be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return expand(SE.getAddExpr(Ops)); 5785be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman} 5795be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 580a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// isNonConstantNegative - Return true if the specified scev is negated, but 581a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// not a constant. 582a10756ee657a4d43a48cca5c166919093930ed6bDan Gohmanstatic bool isNonConstantNegative(const SCEV *F) { 583a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(F); 584a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!Mul) return false; 585a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 586a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If there is a constant factor, it will be first. 587a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVConstant *SC = dyn_cast<SCEVConstant>(Mul->getOperand(0)); 588a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!SC) return false; 589a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 590a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Return true if the value is negative, this matches things like (-42 * V). 591a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return SC->getValue()->getValue().isNegative(); 592a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 593a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 594087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// PickMostRelevantLoop - Given two loops pick the one that's most relevant for 595087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// SCEV expansion. If they are nested, this is the most nested. If they are 596087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// neighboring, pick the later. 597087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanstatic const Loop *PickMostRelevantLoop(const Loop *A, const Loop *B, 598087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT) { 599087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!A) return B; 600087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!B) return A; 601087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (A->contains(B)) return B; 602087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (B->contains(A)) return A; 603087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(A->getHeader(), B->getHeader())) return B; 604087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(B->getHeader(), A->getHeader())) return A; 605087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return A; // Arbitrarily break the tie. 606087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 607087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 608087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// GetRelevantLoop - Get the most relevant loop associated with the given 609087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// expression, according to PickMostRelevantLoop. 610087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanstatic const Loop *GetRelevantLoop(const SCEV *S, LoopInfo &LI, 611087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT) { 612087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<SCEVConstant>(S)) 613087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 614087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) { 615087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const Instruction *I = dyn_cast<Instruction>(U->getValue())) 616087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return LI.getLoopFor(I->getParent()); 617087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 618087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 619087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVNAryExpr *N = dyn_cast<SCEVNAryExpr>(S)) { 620087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *L = 0; 621087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) 622087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman L = AR->getLoop(); 623087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SCEVNAryExpr::op_iterator I = N->op_begin(), E = N->op_end(); 624087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I != E; ++I) 625087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman L = PickMostRelevantLoop(L, GetRelevantLoop(*I, LI, DT), DT); 626087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return L; 627087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 628087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(S)) 629087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return GetRelevantLoop(C->getOperand(), LI, DT); 630087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVUDivExpr *D = dyn_cast<SCEVUDivExpr>(S)) 631087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return PickMostRelevantLoop(GetRelevantLoop(D->getLHS(), LI, DT), 632087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman GetRelevantLoop(D->getRHS(), LI, DT), 633087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DT); 634087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman llvm_unreachable("Unexpected SCEV type!"); 635087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 636c4f7ec85ecb760fff2b702c6deb06506b968ba4fDan Gohman 637b35798347ea87b8b6d36155b211016a7769f01abDan Gohmannamespace { 638b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 639087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// LoopCompare - Compare loops by PickMostRelevantLoop. 640087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanclass LoopCompare { 641087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT; 642087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanpublic: 643087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman explicit LoopCompare(DominatorTree &dt) : DT(dt) {} 644087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 645087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool operator()(std::pair<const Loop *, const SCEV *> LHS, 646087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::pair<const Loop *, const SCEV *> RHS) const { 647087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Compare loops with PickMostRelevantLoop. 648087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (LHS.first != RHS.first) 649087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return PickMostRelevantLoop(LHS.first, RHS.first, DT) != LHS.first; 650087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 651087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // If one operand is a non-constant negative and the other is not, 652087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // put the non-constant negative on the right so that a sub can 653087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // be used instead of a negate and add. 654087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isNonConstantNegative(LHS.second)) { 655087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!isNonConstantNegative(RHS.second)) 656087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 657087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (isNonConstantNegative(RHS.second)) 658087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return true; 659087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 660087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Otherwise they are equivalent according to this comparison. 661087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 662c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 663087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman}; 6645be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 665b35798347ea87b8b6d36155b211016a7769f01abDan Gohman} 666b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 667087bd1e3a12893873761736bf0f905a350e9e708Dan GohmanValue *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { 668087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 669e24fa64d52330626553298f56ba5aa702624c282Dan Gohman 670087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the add operands in a loop, along with their associated loops. 671087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal, and 672087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // so that pointer operands are inserted first, which the code below relies on 673087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // to form more involved GEPs. 674087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 675087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVAddExpr::op_iterator> I(S->op_end()), 676087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 677087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman OpsAndLoops.push_back(std::make_pair(GetRelevantLoop(*I, *SE.LI, *SE.DT), 678087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman *I)); 679087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 680087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants and 681087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // pointer operands precede non-pointer operands. 682087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 683087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 684087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to add all the operands. Hoist as much as possible 685087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops, and form meaningful getelementptrs where possible. 686087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Sum = 0; 687087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 688087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 689087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *CurLoop = I->first; 690087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 691087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Sum) { 692087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 693087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expand(Op); 694087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 695087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (const PointerType *PTy = dyn_cast<PointerType>(Sum->getType())) { 696087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum expression is a pointer. Try to form a getelementptr 697087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // at this level with that as the base. 698087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 699087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (; I != E && I->first == CurLoop; ++I) 700087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman NewOps.push_back(I->second); 701087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum); 702087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (const PointerType *PTy = dyn_cast<PointerType>(Op->getType())) { 703087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum is an integer, and there's a pointer at this level. 704f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // Try to form a getelementptr. If the running sum is instructions, 705f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // use a SCEVUnknown to avoid re-analyzing them. 706087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 707f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman NewOps.push_back(isa<Instruction>(Sum) ? SE.getUnknown(Sum) : 708f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman SE.getSCEV(Sum)); 709087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (++I; I != E && I->first == CurLoop; ++I) 710087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman NewOps.push_back(I->second); 711087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, expand(Op)); 712087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (isNonConstantNegative(Op)) { 713087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a negate and add, just do a subtract. 714a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(SE.getNegativeSCEV(Op), Ty); 715087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 716087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Sub, Sum, W); 717087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 718a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 719087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple add. 720a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(Op, Ty); 721087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 722087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 723087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Sum)) std::swap(Sum, W); 724087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Add, Sum, W); 725087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 726a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 7272d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 728087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 729087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Sum; 730e24fa64d52330626553298f56ba5aa702624c282Dan Gohman} 7315be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 732890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) { 733af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 734087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 735087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the mul operands in a loop, along with their associated loops. 736087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal. 737087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 738087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVMulExpr::op_iterator> I(S->op_end()), 739087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 740087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman OpsAndLoops.push_back(std::make_pair(GetRelevantLoop(*I, *SE.LI, *SE.DT), 741087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman *I)); 742087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 743087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants. 744087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 745087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 746087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to mul all the operands. Hoist as much as possible 747087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops. 748087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Prod = 0; 749087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 750087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 751087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 752087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Prod) { 753087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 754087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = expand(Op); 755087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 756087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (Op->isAllOnesValue()) { 757087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a multiply by negative one, just do a negate. 758087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 759087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Sub, Constant::getNullValue(Ty), Prod); 760087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 761087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else { 762087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple mul. 763087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *W = expandCodeFor(Op, Ty); 764087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 765087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 766087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Prod)) std::swap(Prod, W); 767087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Mul, Prod, W); 768087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 769087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 7702d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 7712d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 772087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Prod; 77336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 77436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 775890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) { 776af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 7772d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 77892fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *LHS = expandCodeFor(S->getLHS(), Ty); 779890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getRHS())) { 7806177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky const APInt &RHS = SC->getValue()->getValue(); 7816177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky if (RHS.isPowerOf2()) 7826177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky return InsertBinop(Instruction::LShr, LHS, 783eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson ConstantInt::get(Ty, RHS.logBase2())); 7846177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky } 7856177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 78692fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getRHS(), Ty); 787267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman return InsertBinop(Instruction::UDiv, LHS, RHS); 7886177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky} 7896177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 790453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Move parts of Base into Rest to leave Base with the minimal 791453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// expression that provides a pointer operand suitable for a 792453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEP expansion. 7930bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic void ExposePointerBase(const SCEV *&Base, const SCEV *&Rest, 794453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ScalarEvolution &SE) { 795453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Base)) { 796453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getStart(); 797453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(Rest, 798deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getAddRecExpr(SE.getConstant(A->getType(), 0), 799453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getStepRecurrence(SE), 800453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getLoop())); 801453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 802453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(Base)) { 803453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getOperand(A->getNumOperands()-1); 8040bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> NewAddOps(A->op_begin(), A->op_end()); 805453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman NewAddOps.back() = Rest; 806453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(NewAddOps); 807453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ExposePointerBase(Base, Rest, SE); 808453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 809453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 810453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 811a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// getAddRecExprPHILiterally - Helper for expandAddRecExprLiterally. Expand 812a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// the base addrec, which is the addrec without any non-loop-dominating 813a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// values, and return the PHI. 814a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanPHINode * 815a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanSCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized, 816a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L, 817a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Type *ExpandTy, 818a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Type *IntTy) { 819a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Reuse a previously-inserted PHI, if present. 820a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman for (BasicBlock::iterator I = L->getHeader()->begin(); 821a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = dyn_cast<PHINode>(I); ++I) 822572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman if (SE.isSCEVable(PN->getType()) && 823572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman (SE.getEffectiveSCEVType(PN->getType()) == 824572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman SE.getEffectiveSCEVType(Normalized->getType())) && 825572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman SE.getSCEV(PN) == Normalized) 826572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman if (BasicBlock *LatchBlock = L->getLoopLatch()) { 827572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman Instruction *IncV = 82822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)); 82922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman 83022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Determine if this is a well-behaved chain of instructions leading 83122e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // back to the PHI. It probably will be, if we're scanning an inner 83222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // loop already visited by LSR for example, but it wouldn't have 83322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // to be. 83422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman do { 83522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (IncV->getNumOperands() == 0 || isa<PHINode>(IncV)) { 83622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = 0; 83722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 83822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } 8399feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // If any of the operands don't dominate the insert position, bail. 8409feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // Addrec operands are always loop-invariant, so this can only happen 8419feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // if there are instructions which haven't been hoisted. 8429feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman for (User::op_iterator OI = IncV->op_begin()+1, 8439feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman OE = IncV->op_end(); OI != OE; ++OI) 8449feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman if (Instruction *OInst = dyn_cast<Instruction>(OI)) 8459feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman if (!SE.DT->dominates(OInst, IVIncInsertPos)) { 8469feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman IncV = 0; 8479feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman break; 8489feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman } 8499feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman if (!IncV) 8509feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman break; 8519feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // Advance to the next instruction. 85222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 85322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (!IncV) 85422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 85522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (IncV->mayHaveSideEffects()) { 85622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = 0; 85722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 85822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } 85922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } while (IncV != PN); 86022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman 86122e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (IncV) { 86222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Ok, the add recurrence looks usable. 86322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Remember this PHI, even in post-inc mode. 86422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman InsertedValues.insert(PN); 86522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Remember the increment. 86622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)); 86722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman rememberInstruction(IncV); 86822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (L == IVIncInsertLoop) 86922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman do { 87022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (SE.DT->dominates(IncV, IVIncInsertPos)) 87122e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 87222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Make sure the increment is where we want it. But don't move it 87322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // down past a potential existing post-inc user. 87422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV->moveBefore(IVIncInsertPos); 87522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IVIncInsertPos = IncV; 87622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = cast<Instruction>(IncV->getOperand(0)); 87722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } while (IncV != PN); 87822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman return PN; 87922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } 880572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman } 881a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 882a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Save the original insertion point so we can restore it when we're done. 883a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 884a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 885a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 886a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the start value. 887a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StartV = expandCodeFor(Normalized->getStart(), ExpandTy, 888a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman L->getHeader()->begin()); 889a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 890a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the step value. Insert instructions right before the 891a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // terminator corresponding to the back-edge. Do this before creating the PHI 892a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // so that PHI reuse code doesn't see an incomplete PHI. If the stride is 893a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // negative, insert a sub instead of an add for the increment (unless it's a 894a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // constant, because subtracts of constants are canonicalized to adds). 895a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 8961df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands bool isPointer = ExpandTy->isPointerTy(); 897a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman bool isNegative = !isPointer && isNonConstantNegative(Step); 898a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (isNegative) 899a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Step = SE.getNegativeSCEV(Step); 900a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StepV = expandCodeFor(Step, IntTy, L->getHeader()->begin()); 901a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 902a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the PHI. 903a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Builder.SetInsertPoint(L->getHeader(), L->getHeader()->begin()); 904a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = Builder.CreatePHI(ExpandTy, "lsr.iv"); 905a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(PN); 906a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 907a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the step instructions and populate the PHI. 908a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *Header = L->getHeader(); 909a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman for (pred_iterator HPI = pred_begin(Header), HPE = pred_end(Header); 910a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman HPI != HPE; ++HPI) { 911a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *Pred = *HPI; 912a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 913a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Add a start value. 914a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!L->contains(Pred)) { 915a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(StartV, Pred); 916a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman continue; 917a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 918a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 919a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create a step value and add it to the PHI. If IVIncInsertLoop is 920a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // non-null and equal to the addrec's loop, insert the instructions 921a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // at IVIncInsertPos. 922a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Instruction *InsertPos = L == IVIncInsertLoop ? 923a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IVIncInsertPos : Pred->getTerminator(); 924a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Builder.SetInsertPoint(InsertPos->getParent(), InsertPos); 925a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *IncV; 926a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If the PHI is a pointer, use a GEP, otherwise use an add or sub. 927a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (isPointer) { 928a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const PointerType *GEPPtrTy = cast<PointerType>(ExpandTy); 929a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If the step isn't constant, don't use an implicitly scaled GEP, because 930a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // that would require a multiply inside the loop. 931a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!isa<ConstantInt>(StepV)) 932a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman GEPPtrTy = PointerType::get(Type::getInt1Ty(SE.getContext()), 933a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman GEPPtrTy->getAddressSpace()); 934a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const StepArray[1] = { SE.getSCEV(StepV) }; 935a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = expandAddToGEP(StepArray, StepArray+1, GEPPtrTy, IntTy, PN); 936a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (IncV->getType() != PN->getType()) { 937a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = Builder.CreateBitCast(IncV, PN->getType(), "tmp"); 938a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(IncV); 939a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 940a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 941a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = isNegative ? 942a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Builder.CreateSub(PN, StepV, "lsr.iv.next") : 943a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Builder.CreateAdd(PN, StepV, "lsr.iv.next"); 944a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(IncV); 945a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 946a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(IncV, Pred); 947a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 948a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 949a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Restore the original insert point. 950a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (SaveInsertBB) 951455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 952a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 953a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Remember this PHI, even in post-inc mode. 954a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman InsertedValues.insert(PN); 955a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 956a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return PN; 957a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 958a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 959a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanValue *SCEVExpander::expandAddRecExprLiterally(const SCEVAddRecExpr *S) { 960a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Type *STy = S->getType(); 961a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Type *IntTy = SE.getEffectiveSCEVType(STy); 962a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L = S->getLoop(); 963a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 964a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Determine a normalized form of this expression, which is the expression 965a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // before any post-inc adjustment is made. 966a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVAddRecExpr *Normalized = S; 967448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (PostIncLoops.count(L)) { 968448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman PostIncLoopSet Loops; 969448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops.insert(L); 970448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Normalized = 971448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman cast<SCEVAddRecExpr>(TransformForPostIncUse(Normalize, S, 0, 0, 972448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops, SE, *SE.DT)); 973a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 974a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 975a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec start. 976a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Start = Normalized->getStart(); 977a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopOffset = 0; 978a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!Start->properlyDominates(L->getHeader(), SE.DT)) { 979a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopOffset = Start; 980deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Start = SE.getConstant(Normalized->getType(), 0); 981a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized = 982a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start, 983a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized->getStepRecurrence(SE), 984a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized->getLoop())); 985a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 986a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 987a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec step. 988a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 989a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopScale = 0; 990948c8a3e3d7349c67e5d9231d9e99b2692623630Dan Gohman if (!Step->dominates(L->getHeader(), SE.DT)) { 991a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopScale = Step; 992deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Step = SE.getConstant(Normalized->getType(), 1); 993a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized = 994a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start, Step, 995a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized->getLoop())); 996a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 997a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 998a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand the core addrec. If we need post-loop scaling, force it to 999a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // expand to an integer type to avoid the need for additional casting. 1000a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Type *ExpandTy = PostLoopScale ? IntTy : STy; 1001a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = getAddRecExprPHILiterally(Normalized, L, ExpandTy, IntTy); 1002a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 10033f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // Accommodate post-inc mode, if necessary. 1004a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Result; 1005448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (!PostIncLoops.count(L)) 1006a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN; 1007a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman else { 1008a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // In PostInc mode, use the post-incremented value. 1009a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *LatchBlock = L->getLoopLatch(); 1010a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman assert(LatchBlock && "PostInc mode requires a unique loop latch!"); 1011a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN->getIncomingValueForBlock(LatchBlock); 1012a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1013a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1014a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating scale. 1015a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopScale) { 10160a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1017a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateMul(Result, 1018a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopScale, IntTy)); 1019a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1020a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1021a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1022a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating offset. 1023a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopOffset) { 1024a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (const PointerType *PTy = dyn_cast<PointerType>(ExpandTy)) { 1025a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const OffsetArray[1] = { PostLoopOffset }; 1026a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = expandAddToGEP(OffsetArray, OffsetArray+1, PTy, IntTy, Result); 1027a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 10280a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1029a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateAdd(Result, 1030a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopOffset, IntTy)); 1031a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1032a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1033a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1034a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1035a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return Result; 1036a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1037a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1038890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { 1039a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!CanonicalMode) return expandAddRecExprLiterally(S); 1040a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1041af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 104236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Loop *L = S->getLoop(); 104336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 10444d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // First check for an existing canonical IV in a suitable type. 10454d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman PHINode *CanonicalIV = 0; 10464d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (PHINode *PN = L->getCanonicalInductionVariable()) 10474d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (SE.isSCEVable(PN->getType()) && 10481df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands SE.getEffectiveSCEVType(PN->getType())->isIntegerTy() && 10494d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty)) 10504d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV = PN; 10514d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 10524d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Rewrite an AddRec in terms of the canonical induction variable, if 10534d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // its type is more narrow. 10544d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (CanonicalIV && 10554d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(CanonicalIV->getType()) > 10564d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(Ty)) { 1057f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->getNumOperands()); 1058f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman for (unsigned i = 0, e = S->getNumOperands(); i != e; ++i) 1059f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman NewOps[i] = SE.getAnyExtendExpr(S->op_begin()[i], CanonicalIV->getType()); 1060f3f1be6f065d1b90afe80ca80c9d6473c10deb5aDan Gohman Value *V = expand(SE.getAddRecExpr(NewOps, S->getLoop())); 1061267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1062267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 10634d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman BasicBlock::iterator NewInsertPt = 10647896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner llvm::next(BasicBlock::iterator(cast<Instruction>(V))); 106508f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach while (isa<PHINode>(NewInsertPt) || isa<DbgInfoIntrinsic>(NewInsertPt)) 106608f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach ++NewInsertPt; 10674d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), 0, 10684d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewInsertPt); 1069455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 10704d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman return V; 10714d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman } 10724d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 107336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {X,+,F} --> X + {0,+,F} 1074cfeb6a450632f2a6cd05302633c8c2b8c90cfdfdDan Gohman if (!S->getStart()->isZero()) { 1075f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->op_begin(), S->op_end()); 1076deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman NewOps[0] = SE.getConstant(Ty, 0); 10770bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Rest = SE.getAddRecExpr(NewOps, L); 1078453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 1079453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the 1080453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // comments on expandAddToGEP for details. 1081c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Base = S->getStart(); 1082c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *RestArray[1] = { Rest }; 1083c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Dig into the expression to find the pointer base for a GEP. 1084c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ExposePointerBase(Base, RestArray[0], SE); 1085c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If we found a pointer, expand the AddRec with a GEP. 1086c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const PointerType *PTy = dyn_cast<PointerType>(Base->getType())) { 1087c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Make sure the Base isn't something exotic, such as a multiplied 1088c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // or divided pointer value. In those cases, the result type isn't 1089c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // actually a pointer type. 1090c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!isa<SCEVMulExpr>(Base) && !isa<SCEVUDivExpr>(Base)) { 1091c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *StartV = expand(Base); 1092c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman assert(StartV->getType() == PTy && "Pointer type mismatch for GEP!"); 1093c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return expandAddToGEP(RestArray, RestArray+1, PTy, Ty, StartV); 1094453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1095453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1096453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 109740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Just do a normal add. Pre-expand the operands to suppress folding. 109840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return expand(SE.getAddExpr(SE.getUnknown(expand(S->getStart())), 109940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getUnknown(expand(Rest)))); 110036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 110136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 110236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {0,+,1} --> Insert a canonical induction variable into the loop! 110317f1972c770dc18f5c7c3c95776b4d62ae9e121dDan Gohman if (S->isAffine() && 1104deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman S->getOperand(1) == SE.getConstant(Ty, 1)) { 11054d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // If there's a canonical IV, just use it. 11064d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (CanonicalIV) { 11074d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) && 11084d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman "IVs with types different from the canonical IV should " 11094d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman "already have been handled!"); 11104d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman return CanonicalIV; 11114d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman } 11124d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 111336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Create and insert the PHI node for the induction variable in the 111436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // specified loop. 111536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman BasicBlock *Header = L->getHeader(); 1116051a950000e21935165db56695e35bade668193bGabor Greif PHINode *PN = PHINode::Create(Ty, "indvar", Header->begin()); 1117a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(PN); 111836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1119eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Constant *One = ConstantInt::get(Ty, 1); 112083d577490b1473213b6973236110c28e59127956Dan Gohman for (pred_iterator HPI = pred_begin(Header), HPE = pred_end(Header); 112183d577490b1473213b6973236110c28e59127956Dan Gohman HPI != HPE; ++HPI) 112283d577490b1473213b6973236110c28e59127956Dan Gohman if (L->contains(*HPI)) { 11233abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // Insert a unit add instruction right before the terminator 11243abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // corresponding to the back-edge. 112583d577490b1473213b6973236110c28e59127956Dan Gohman Instruction *Add = BinaryOperator::CreateAdd(PN, One, "indvar.next", 112683d577490b1473213b6973236110c28e59127956Dan Gohman (*HPI)->getTerminator()); 1127a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Add); 112883d577490b1473213b6973236110c28e59127956Dan Gohman PN->addIncoming(Add, *HPI); 112983d577490b1473213b6973236110c28e59127956Dan Gohman } else { 113083d577490b1473213b6973236110c28e59127956Dan Gohman PN->addIncoming(Constant::getNullValue(Ty), *HPI); 113183d577490b1473213b6973236110c28e59127956Dan Gohman } 113236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 113336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11344d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // {0,+,F} --> {0,+,1} * F 113536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Get the canonical induction variable I for this loop. 11364d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman Value *I = CanonicalIV ? 11374d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV : 11384d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman getOrInsertCanonicalInductionVariable(L, Ty); 113936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1140df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If this is a simple linear addrec, emit it now as a special case. 114140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (S->isAffine()) // {0,+,F} --> i*F 114240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return 114340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman expand(SE.getTruncateOrNoop( 114440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getMulExpr(SE.getUnknown(I), 114540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getNoopOrAnyExtend(S->getOperand(1), 114640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman I->getType())), 114740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Ty)); 114836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 114936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // If this is a chain of recurrences, turn it into a closed form, using the 115036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // folders, then expandCodeFor the closed form. This allows the folders to 115136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // simplify the expression without having to build a bunch of special code 115236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // into this folder. 11530bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *IH = SE.getUnknown(I); // Get I as a "symbolic" SCEV. 115436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11554d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Promote S up to the canonical IV type, if the cast is foldable. 11560bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *NewS = S; 11570bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Ext = SE.getNoopOrAnyExtend(S, I->getType()); 11584d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (isa<SCEVAddRecExpr>(Ext)) 11594d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewS = Ext; 11604d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 11610bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE); 1162e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; 116336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11644d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Truncate the result down to the original type, if needed. 11650bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *T = SE.getTruncateOrNoop(V, Ty); 1166469f3cdc13851914f3a766cbd8f701cf8431cacaDan Gohman return expand(T); 116736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 116896fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 1169890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitTruncateExpr(const SCEVTruncateExpr *S) { 1170af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 117192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 117292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1173267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateTrunc(V, Ty, "tmp"); 1174a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1175cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 117611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 117711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1178890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitZeroExtendExpr(const SCEVZeroExtendExpr *S) { 1179af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 118092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 118192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1182267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateZExt(V, Ty, "tmp"); 1183a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1184cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 118511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 118611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1187890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) { 1188af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 118992fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 119092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1191267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateSExt(V, Ty, "tmp"); 1192a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1193cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 119411f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 119511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1196890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { 11970196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 11980196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman const Type *Ty = LHS->getType(); 11990196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 12000196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 12010196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 12020196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 12030196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 12040196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 12050196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 120692fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1207267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *ICmp = Builder.CreateICmpSGT(LHS, RHS, "tmp"); 1208a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1209267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "smax"); 1210a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1211cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 1212c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky } 12130196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 12140196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 12150196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 12160196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 1217c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky return LHS; 1218c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky} 1219c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky 1220890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { 12210196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 12220196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman const Type *Ty = LHS->getType(); 12230196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 12240196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 12250196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 12260196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 12270196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 12280196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 12290196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 123092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1231267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *ICmp = Builder.CreateICmpUGT(LHS, RHS, "tmp"); 1232a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1233267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "umax"); 1234a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1235cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 12363e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky } 12370196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 12380196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 12390196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 12400196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 12413e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky return LHS; 12423e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky} 12433e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky 12446c7ed6b54949949806797bafdf545fbfecb2cef5Dan GohmanValue *SCEVExpander::expandCodeFor(const SCEV *SH, const Type *Ty, 12456c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Instruction *I) { 12466c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman BasicBlock::iterator IP = I; 12476c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(IP) || isa<DbgInfoIntrinsic>(IP)) 12486c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman ++IP; 12496c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Builder.SetInsertPoint(IP->getParent(), IP); 12506c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman return expandCodeFor(SH, Ty); 12516c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman} 12526c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman 12530bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandCodeFor(const SCEV *SH, const Type *Ty) { 125411f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman // Expand the code for this SCEV. 12552d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *V = expand(SH); 12565be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Ty) { 12575be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman assert(SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(SH->getType()) && 12585be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman "non-trivial casts should be done with the SCEVs directly!"); 12595be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, Ty); 12605be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 12615be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return V; 126211f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 126311f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1264890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::expand(const SCEV *S) { 126540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Compute an insertion point for this SCEV object. Hoist the instructions 126640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // as far out in the loop nest as possible. 1267267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *InsertPt = Builder.GetInsertPoint(); 1268267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman for (Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock()); ; 126940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman L = L->getParentLoop()) 127040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (S->isLoopInvariant(L)) { 127140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (!L) break; 1272e059ee832ca36d65a5fb87b0ac5bcdb0490b15cbDan Gohman if (BasicBlock *Preheader = L->getLoopPreheader()) 127340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = Preheader->getTerminator(); 127440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } else { 127540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // If the SCEV is computable at this level, insert it into the header 127640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // after the PHIs (and after any other instructions that we've inserted 127740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // there) so that it is guaranteed to dominate any user inside the loop. 1278448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (L && S->hasComputableLoopEvolution(L) && !PostIncLoops.count(L)) 127940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = L->getHeader()->getFirstNonPHI(); 12806c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(InsertPt) || isa<DbgInfoIntrinsic>(InsertPt)) 12817896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner InsertPt = llvm::next(BasicBlock::iterator(InsertPt)); 128240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman break; 128340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } 128440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1285667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Check to see if we already expanded this here. 1286667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman std::map<std::pair<const SCEV *, Instruction *>, 1287667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman AssertingVH<Value> >::iterator I = 1288667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman InsertedExpressions.find(std::make_pair(S, InsertPt)); 1289267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (I != InsertedExpressions.end()) 1290667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman return I->second; 1291267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 1292267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1293267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1294267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(InsertPt->getParent(), InsertPt); 1295667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1296667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Expand the expression into instructions. 129796fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov Value *V = visit(S); 129840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1299667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Remember the expanded value for this SCEV at this location. 1300448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (PostIncLoops.empty()) 1301a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman InsertedExpressions[std::make_pair(S, InsertPt)] = V; 1302667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1303455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 130496fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return V; 130596fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov} 13061d09de3eca23267855e28297fcb40de3632ea47bDan Gohman 13071d826a76f591afea445489b9a5485c345e66bf87Dan Gohmanvoid SCEVExpander::rememberInstruction(Value *I) { 130825fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman if (!PostIncLoops.empty()) 130925fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman InsertedPostIncValues.insert(I); 131025fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman else 13111d826a76f591afea445489b9a5485c345e66bf87Dan Gohman InsertedValues.insert(I); 13121d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 13131d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // If we just claimed an existing instruction and that instruction had 13141d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // been the insert point, adjust the insert point forward so that 13151d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // subsequently inserted code will be dominated. 13161d826a76f591afea445489b9a5485c345e66bf87Dan Gohman if (Builder.GetInsertPoint() == I) { 13171d826a76f591afea445489b9a5485c345e66bf87Dan Gohman BasicBlock::iterator It = cast<Instruction>(I); 13186c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman do { ++It; } while (isInsertedInstruction(It) || 13196c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman isa<DbgInfoIntrinsic>(It)); 13201d826a76f591afea445489b9a5485c345e66bf87Dan Gohman Builder.SetInsertPoint(Builder.GetInsertBlock(), It); 13211d826a76f591afea445489b9a5485c345e66bf87Dan Gohman } 13221d826a76f591afea445489b9a5485c345e66bf87Dan Gohman} 13231d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 1324455985501381777db03534c925a35e261e356395Dan Gohmanvoid SCEVExpander::restoreInsertPoint(BasicBlock *BB, BasicBlock::iterator I) { 13253f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If we acquired more instructions since the old insert point was saved, 1326455985501381777db03534c925a35e261e356395Dan Gohman // advance past them. 13276c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(I) || isa<DbgInfoIntrinsic>(I)) ++I; 1328455985501381777db03534c925a35e261e356395Dan Gohman 1329455985501381777db03534c925a35e261e356395Dan Gohman Builder.SetInsertPoint(BB, I); 1330455985501381777db03534c925a35e261e356395Dan Gohman} 1331455985501381777db03534c925a35e261e356395Dan Gohman 13321d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// getOrInsertCanonicalInductionVariable - This method returns the 13331d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// canonical induction variable of the specified type for the specified 13341d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// loop (inserting one if there is none). A canonical induction variable 13351d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// starts at zero and steps by one on each iteration. 13361d09de3eca23267855e28297fcb40de3632ea47bDan GohmanValue * 13371d09de3eca23267855e28297fcb40de3632ea47bDan GohmanSCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L, 13381d09de3eca23267855e28297fcb40de3632ea47bDan Gohman const Type *Ty) { 1339b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands assert(Ty->isIntegerTy() && "Can only insert integer induction variables!"); 1340deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *H = SE.getAddRecExpr(SE.getConstant(Ty, 0), 1341deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getConstant(Ty, 1), L); 1342267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1343267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 134440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Value *V = expandCodeFor(H, 0, L->getHeader()->begin()); 1345267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (SaveInsertBB) 1346455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 134740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return V; 13481d09de3eca23267855e28297fcb40de3632ea47bDan Gohman} 1349