ScalarEvolutionExpander.cpp revision a4c86ab073d4b7a36477fc7c54c9d52499f04586
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" 22d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 2336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begemanusing namespace llvm; 2436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 2519e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif/// ReuseOrCreateCast - Arrange for there to be a cast of V to Ty at IP, 26485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// reusing an existing cast if a suitable one exists, moving an existing 27485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// cast if a suitable one exists but isn't in the right place, or 2819e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif/// creating a new one. 29db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::ReuseOrCreateCast(Value *V, Type *Ty, 30485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction::CastOps Op, 31485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP) { 32485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Check to see if there is already a cast! 33485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); 34f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif UI != E; ++UI) { 35f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif User *U = *UI; 36f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif if (U->getType() == Ty) 3719e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif if (CastInst *CI = dyn_cast<CastInst>(U)) 38485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (CI->getOpcode() == Op) { 39485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // If the cast isn't where we want it, fix it. 40485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (BasicBlock::iterator(CI) != IP) { 41485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast, and leave the old cast in place in case 42485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // it is being used as an insert point. Clear its operand 43485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // so that it doesn't hold anything live. 44485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *NewCI = CastInst::Create(Op, V, Ty, "", IP); 45485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman NewCI->takeName(CI); 46485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->replaceAllUsesWith(NewCI); 47485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->setOperand(0, UndefValue::get(V->getType())); 48485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(NewCI); 49485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return NewCI; 50485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 516f5fed253f58645bf45448893a585ffbd9914989Dan Gohman rememberInstruction(CI); 52485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return CI; 53485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 54f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif } 55485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 56485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast. 57485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *I = CastInst::Create(Op, V, Ty, V->getName(), IP); 58485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(I); 59485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return I; 60485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman} 61485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 62267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// InsertNoopCastOfTo - Insert a cast of V to the specified type, 63267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// which must be possible with a noop cast, doing what we can to share 64267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// the casts. 65db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::InsertNoopCastOfTo(Value *V, Type *Ty) { 66267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction::CastOps Op = CastInst::getCastOpcode(V, false, Ty, false); 67267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert((Op == Instruction::BitCast || 68267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::PtrToInt || 69267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::IntToPtr) && 70267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot perform non-noop casts!"); 71267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert(SE.getTypeSizeInBits(V->getType()) == SE.getTypeSizeInBits(Ty) && 72267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot change sizes!"); 73267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 742d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman // Short-circuit unnecessary bitcasts. 75267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (Op == Instruction::BitCast && V->getType() == Ty) 762d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman return V; 772d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 78f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman // Short-circuit unnecessary inttoptr<->ptrtoint casts. 79267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if ((Op == Instruction::PtrToInt || Op == Instruction::IntToPtr) && 8080dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) { 81af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if (CastInst *CI = dyn_cast<CastInst>(V)) 82af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if ((CI->getOpcode() == Instruction::PtrToInt || 83af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman CI->getOpcode() == Instruction::IntToPtr) && 84af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getType()) == 85af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getOperand(0)->getType())) 86af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return CI->getOperand(0); 8780dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 8880dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if ((CE->getOpcode() == Instruction::PtrToInt || 8980dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman CE->getOpcode() == Instruction::IntToPtr) && 9080dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getType()) == 9180dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getOperand(0)->getType())) 9280dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman return CE->getOperand(0); 9380dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman } 94f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman 95485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Fold a cast of a constant. 96ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 97baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Op, C, Ty); 984c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman 99485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the argument at the beginning of the entry block, after 100485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // any bitcasts of other arguments. 101ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Argument *A = dyn_cast<Argument>(V)) { 102485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP = A->getParent()->getEntryBlock().begin(); 103485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman while ((isa<BitCastInst>(IP) && 104485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman isa<Argument>(cast<BitCastInst>(IP)->getOperand(0)) && 105485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman cast<BitCastInst>(IP)->getOperand(0) != A) || 106a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<DbgInfoIntrinsic>(IP) || 107a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(IP)) 108485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman ++IP; 109485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(A, Ty, Op, IP); 110ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 1113913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 112485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the instruction immediately after the instruction. 113ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner Instruction *I = cast<Instruction>(V); 114ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner BasicBlock::iterator IP = I; ++IP; 115ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(I)) 116ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner IP = II->getNormalDest()->begin(); 117a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling while (isa<PHINode>(IP) || isa<DbgInfoIntrinsic>(IP) || 118a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(IP)) 119a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling ++IP; 120485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(I, Ty, Op, IP); 121ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner} 122ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 1237fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// InsertBinop - Insert the specified binary operator, doing a small amount 1247fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// of work to avoid inserting an obviously redundant operation. 125267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, 126267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *LHS, Value *RHS) { 1270f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman // Fold a binop with constant operands. 1280f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(LHS)) 1290f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(RHS)) 130baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, CLHS, CRHS); 1310f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman 1327fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner // Do a quick scan to see if we have this binop nearby. If so, reuse it. 1337fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner unsigned ScanLimit = 6; 134267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 135267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 136267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 137267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 1388a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz --IP; 1398a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz for (; ScanLimit; --IP, --ScanLimit) { 1408d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 1418d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 1428d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 1438d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 1445be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == (unsigned)Opcode && IP->getOperand(0) == LHS && 1455be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(1) == RHS) 1465be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 1478a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (IP == BlockBegin) break; 1488a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz } 1497fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner } 150267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 151087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 152087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 153087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 154087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 155087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 156087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 157087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(LHS) || !L->isLoopInvariant(RHS)) break; 158087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 159087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 160087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 161087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 162087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 163087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 164087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 1658a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // If we haven't found this binop, insert it. 166df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel Instruction *BO = cast<Instruction>(Builder.CreateBinOp(Opcode, LHS, RHS, "tmp")); 167df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel BO->setDebugLoc(SaveInsertPt->getDebugLoc()); 168a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(BO); 169087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 170087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 171087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 172087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 173087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 174cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return BO; 1757fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner} 1767fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner 1774a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// FactorOutConstant - Test if S is divisible by Factor, using signed 178453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// division. If so, update S with Factor divided out and return true. 1793f46a3abeedba8d517b4182de34c821d752db058Dan Gohman/// S need not be evenly divisible if a reasonable remainder can be 1804a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// computed. 181453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// TODO: When ScalarEvolution gets a SCEVSDivExpr, this can be made 182453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// unnecessary; in its place, just signed-divide Ops[i] by the scale and 183453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// check to see if the divide was folded. 1840bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic bool FactorOutConstant(const SCEV *&S, 1850bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *&Remainder, 186c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Factor, 187c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE, 188c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const TargetData *TD) { 189453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Everything is divisible by one. 190c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Factor->isOne()) 191c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 192c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 193c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // x/x == 1. 194c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (S == Factor) { 195deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman S = SE.getConstant(S->getType(), 1); 196453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 197c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 198453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 199453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // For a Constant, check for a multiple of the given factor. 2004a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S)) { 201c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // 0/x == 0. 202c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (C->isZero()) 203453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 204c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Check for divisibility. 205c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *FC = dyn_cast<SCEVConstant>(Factor)) { 206c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt *CI = 207c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt::get(SE.getContext(), 208c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman C->getValue()->getValue().sdiv( 209c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 210c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the quotient is zero and the remainder is non-zero, reject 211c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the value at this scale. It will be considered for subsequent 212c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // smaller scales. 213c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!CI->isZero()) { 214c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Div = SE.getConstant(CI); 215c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = Div; 216c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder = 217c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(Remainder, 218c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().srem( 219c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue()))); 220c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 221c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 222453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 2234a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman } 224453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 225453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In a Mul, check if there is a constant operand which is a multiple 226453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // of the given factor. 227c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S)) { 228c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (TD) { 229c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, the size is known. Check if there is a constant 230c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // operand which is a multiple of the given factor. If so, we can 231c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // factor it. 232c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEVConstant *FC = cast<SCEVConstant>(Factor); 233c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0))) 234c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!C->getValue()->getValue().srem(FC->getValue()->getValue())) { 235f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 236c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[0] = 237c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().sdiv( 238c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 239c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 240c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 241c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 242c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 243c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Without TargetData, check if Factor can be factored out of any of the 244c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Mul's operands. If so, we can just remove it. 245c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) { 246c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *SOp = M->getOperand(i); 247deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(SOp->getType(), 0); 248c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (FactorOutConstant(SOp, Remainder, Factor, SE, TD) && 249c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder->isZero()) { 250f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 251c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[i] = SOp; 252c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 253c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 254c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 255453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 256c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 257c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 258453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 259453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In an AddRec, check if both start and step are divisible. 260453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(S)) { 2610bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Step = A->getStepRecurrence(SE); 262deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *StepRem = SE.getConstant(Step->getType(), 0); 263c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Step, StepRem, Factor, SE, TD)) 2644a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2654a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (!StepRem->isZero()) 2664a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2670bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Start = A->getStart(); 268c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Start, Remainder, Factor, SE, TD)) 269453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 2703228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: can use A->getNoWrapFlags(FlagNW) 2713228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick S = SE.getAddRecExpr(Start, Step, A->getLoop(), SCEV::FlagAnyWrap); 272453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 273453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 274453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 275453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 276453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 277453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 278c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SimplifyAddOperands - Sort and simplify a list of add operands. NumAddRecs 279c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// is the number of SCEVAddRecExprs present, which are kept at the end of 280c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// the list. 281c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 282c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SimplifyAddOperands(SmallVectorImpl<const SCEV *> &Ops, 283db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 284c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 285c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman unsigned NumAddRecs = 0; 286c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = Ops.size(); i > 0 && isa<SCEVAddRecExpr>(Ops[i-1]); --i) 287c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ++NumAddRecs; 288c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Group Ops into non-addrecs and addrecs. 289c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> NoAddRecs(Ops.begin(), Ops.end() - NumAddRecs); 290c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs(Ops.end() - NumAddRecs, Ops.end()); 291c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Let ScalarEvolution sort and simplify the non-addrecs list. 292c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Sum = NoAddRecs.empty() ? 293deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getConstant(Ty, 0) : 294c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(NoAddRecs); 295c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If it returned an add, use the operands. Otherwise it simplified 296c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the sum into a single value, so just use that. 297f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.clear(); 298c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Sum)) 299403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 300f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman else if (!Sum->isZero()) 301f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.push_back(Sum); 302c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Then append the addrecs. 303403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 304c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 305c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 306c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SplitAddRecs - Flatten a list of add operands, moving addrec start values 307c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// out to the top level. For example, convert {a + b,+,c} to a, b, {0,+,d}. 308c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// This helps expose more opportunities for folding parts of the expressions 309c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// into GEP indices. 310c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 311c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SplitAddRecs(SmallVectorImpl<const SCEV *> &Ops, 312db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 313c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 314c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Find the addrecs. 315c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs; 316c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 317c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) { 318c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Start = A->getStart(); 319c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Start->isZero()) break; 320deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Zero = SE.getConstant(Ty, 0); 321c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AddRecs.push_back(SE.getAddRecExpr(Zero, 322c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getStepRecurrence(SE), 3233228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick A->getLoop(), 3243228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: A->getNoWrapFlags(FlagNW) 3253228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 326c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Start)) { 327c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Zero; 328403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 329c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman e += Add->getNumOperands(); 330c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 331c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Start; 332c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 333c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 334c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!AddRecs.empty()) { 335c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Add the addrecs onto the end of the list. 336403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 337c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Resort the operand list, moving any constants to the front. 338c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 339c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 340c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 341c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 3424c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// expandAddToGEP - Expand an addition expression with a pointer type into 3434c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps 3444c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// BasicAliasAnalysis and other passes analyze the result. See the rules 3454c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for getelementptr vs. inttoptr in 3464c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// http://llvm.org/docs/LangRef.html#pointeraliasing 3474c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for details. 34813c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// 3493abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman/// Design note: The correctness of using getelementptr here depends on 3504c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as 3514c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// they may introduce pointer arithmetic which may not be safely converted 3524c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// into getelementptr. 353453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 354453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Design note: It might seem desirable for this function to be more 355453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-aware. If some of the indices are loop-invariant while others 356453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// aren't, it might seem desirable to emit multiple GEPs, keeping the 357453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of the overall computation outside the loop. 358453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// However, there are a few reasons this is not done here. Hoisting simple 359453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// arithmetic is a low-level optimization that often isn't very 360453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// important until late in the optimization process. In fact, passes 361453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// like InstructionCombining will combine GEPs, even if it means 362453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// pushing loop-invariant computation down into loops, so even if the 363453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEPs were split here, the work would quickly be undone. The 364453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// LoopStrengthReduction pass, which is usually run quite late (and 365453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// after the last InstructionCombining pass), takes care of hoisting 366453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of expressions, after considering what 367453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// can be folded using target addressing modes. 368453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 3690bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin, 3700bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *const *op_end, 371db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner PointerType *PTy, 372db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 3735be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *V) { 374db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ElTy = PTy->getElementType(); 3755be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman SmallVector<Value *, 4> GepIndices; 3760bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> Ops(op_begin, op_end); 3775be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman bool AnyNonZeroIndices = false; 3785be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 379c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Split AddRecs up into parts as either of the parts may be usable 380c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // without the other. 381c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SplitAddRecs(Ops, Ty, SE); 382c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 383eb35699e642f2c021f04154bdb4bd90a1afb3baaBob Wilson // Descend down the pointer's type and attempt to convert the other 3845be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // operands into GEP indices, at each level. The first index in a GEP 3855be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // indexes into the array implied by the pointer operand; the rest of 3865be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the indices index into the element or field type selected by the 3875be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // preceding index. 3885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (;;) { 389c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the scale size is not 0, attempt to factor out a scale for 390c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // array indexing. 3910bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> ScaledOps; 392150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (ElTy->isSized()) { 3934f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const SCEV *ElSize = SE.getSizeOfExpr(ElTy); 394150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ElSize->isZero()) { 395150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SmallVector<const SCEV *, 8> NewOps; 396150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 397150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman const SCEV *Op = Ops[i]; 398deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(Ty, 0); 399150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (FactorOutConstant(Op, Remainder, ElSize, SE, SE.TD)) { 400150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // Op now has ElSize factored out. 401150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman ScaledOps.push_back(Op); 402150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!Remainder->isZero()) 403150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Remainder); 404150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman AnyNonZeroIndices = true; 405150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } else { 406150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // The operand was not divisible, so add it to the list of operands 407150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // we'll scan next iteration. 408150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Ops[i]); 409150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 410150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 411150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // If we made any changes, update Ops. 412150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ScaledOps.empty()) { 413150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman Ops = NewOps; 414150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 4155be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 416c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4175be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 418c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 419c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Record the scaled array index for this level of the type. If 420c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // we didn't find any operands that could be factored, tentatively 421c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // assume that element zero was selected (since the zero offset 422c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // would obviously be folded away). 4235be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *Scaled = ScaledOps.empty() ? 424a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant::getNullValue(Ty) : 4255be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman expandCodeFor(SE.getAddExpr(ScaledOps), Ty); 4265be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman GepIndices.push_back(Scaled); 4275be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4285be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Collect struct field index operands. 429db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner while (StructType *STy = dyn_cast<StructType>(ElTy)) { 430c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman bool FoundFieldNo = false; 431c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // An empty struct has no fields. 432c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (STy->getNumElements() == 0) break; 433c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (SE.TD) { 434c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, field offsets are known. See if a constant offset 435c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // falls within any of the struct fields. 436c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Ops.empty()) break; 4375be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[0])) 4385be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (SE.getTypeSizeInBits(C->getType()) <= 64) { 4395be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const StructLayout &SL = *SE.TD->getStructLayout(STy); 4405be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman uint64_t FullOffset = C->getValue()->getZExtValue(); 4415be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (FullOffset < SL.getSizeInBytes()) { 4425be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(FullOffset); 4431d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson GepIndices.push_back( 4441d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson ConstantInt::get(Type::getInt32Ty(Ty->getContext()), ElIdx)); 4455be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = STy->getTypeAtIndex(ElIdx); 4465be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops[0] = 4476de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman SE.getConstant(Ty, FullOffset - SL.getElementOffset(ElIdx)); 4485be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman AnyNonZeroIndices = true; 449c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 4505be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4515be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 452c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 4530f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman // Without TargetData, just check for an offsetof expression of the 454c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // appropriate struct type. 455c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 4560f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Ops[i])) { 457db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *CTy; 4580f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman Constant *FieldNo; 4594f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (U->isOffsetOf(CTy, FieldNo) && CTy == STy) { 4600f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman GepIndices.push_back(FieldNo); 4610f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman ElTy = 4620f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman STy->getTypeAtIndex(cast<ConstantInt>(FieldNo)->getZExtValue()); 463c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = SE.getConstant(Ty, 0); 464c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AnyNonZeroIndices = true; 465c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 466c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 467c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4680f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman } 4695be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 470c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If no struct field offsets were found, tentatively assume that 471c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // field zero was selected (since the zero offset would obviously 472c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // be folded away). 473c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FoundFieldNo) { 474c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ElTy = STy->getTypeAtIndex(0u); 475c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman GepIndices.push_back( 476c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Constant::getNullValue(Type::getInt32Ty(Ty->getContext()))); 477c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 478c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4795be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 480db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (ArrayType *ATy = dyn_cast<ArrayType>(ElTy)) 4815be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = ATy->getElementType(); 482c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman else 483c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 4845be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4855be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4863f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If none of the operands were convertible to proper GEP indices, cast 4875be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the base to i8* and do an ugly getelementptr with that. It's still 4885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // better than ptrtoint+arithmetic+inttoptr at least. 4895be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (!AnyNonZeroIndices) { 490c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Cast the base to i8*. 4915be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, 492ac53a0b272452013124bfc70480aea5e41b60f40Duncan Sands Type::getInt8PtrTy(Ty->getContext(), PTy->getAddressSpace())); 493c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 494c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Expand the operands for a plain byte offset. 49592fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *Idx = expandCodeFor(SE.getAddExpr(Ops), Ty); 4965be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4975be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Fold a GEP with constant operands. 4985be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(V)) 4995be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(Idx)) 500dab3d29605a5c83db41b28176273ef55961120c1Jay Foad return ConstantExpr::getGetElementPtr(CLHS, CRHS); 5015be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 5025be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Do a quick scan to see if we have this GEP nearby. If so, reuse it. 5035be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ScanLimit = 6; 504267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 505267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 506267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 507267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 5085be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman --IP; 5095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (; ScanLimit; --IP, --ScanLimit) { 5108d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 5118d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 5128d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 5138d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 5145be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == Instruction::GetElementPtr && 5155be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(0) == V && IP->getOperand(1) == Idx) 5165be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 5175be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP == BlockBegin) break; 5185be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5195be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5205be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 521087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 522087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 523087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 524087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 525087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 526087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 527087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V) || !L->isLoopInvariant(Idx)) break; 528087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 529087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 530087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 531087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 532087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 533087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 534087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 535c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Emit a GEP. 536c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *GEP = Builder.CreateGEP(V, Idx, "uglygep"); 537a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 538087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 539087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 540087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 541087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 542087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5435be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return GEP; 5445be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5455be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 546087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 547087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 548087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 549087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 550087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 551087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 552087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V)) break; 553087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 554087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool AnyIndexNotLoopInvariant = false; 555087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<Value *>::const_iterator I = GepIndices.begin(), 556087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E = GepIndices.end(); I != E; ++I) 557087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(*I)) { 558087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman AnyIndexNotLoopInvariant = true; 559087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 560087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 561087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (AnyIndexNotLoopInvariant) 562087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 563087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 564087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 565087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 566087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 567087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 568087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 569087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 570087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 571d6aa02de1076c801ac41295156a2379637976918Dan Gohman // Insert a pretty getelementptr. Note that this GEP is not marked inbounds, 572d6aa02de1076c801ac41295156a2379637976918Dan Gohman // because ScalarEvolution may have changed the address arithmetic to 573d6aa02de1076c801ac41295156a2379637976918Dan Gohman // compute a value which is beyond the end of the allocated object. 574a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Casted = V; 575a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (V->getType() != PTy) 576a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Casted = InsertNoopCastOfTo(Casted, PTy); 577a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *GEP = Builder.CreateGEP(Casted, 5780a2a60ace9b79164b71794ce7ff981171c61e442Jay Foad GepIndices, 579267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "scevgep"); 5805be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops.push_back(SE.getUnknown(GEP)); 581a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 582087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 583087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 584087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 585087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 586087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5875be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return expand(SE.getAddExpr(Ops)); 5885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman} 5895be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 590a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// isNonConstantNegative - Return true if the specified scev is negated, but 591a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// not a constant. 592a10756ee657a4d43a48cca5c166919093930ed6bDan Gohmanstatic bool isNonConstantNegative(const SCEV *F) { 593a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(F); 594a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!Mul) return false; 595a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 596a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If there is a constant factor, it will be first. 597a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVConstant *SC = dyn_cast<SCEVConstant>(Mul->getOperand(0)); 598a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!SC) return false; 599a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 600a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Return true if the value is negative, this matches things like (-42 * V). 601a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return SC->getValue()->getValue().isNegative(); 602a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 603a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 604087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// PickMostRelevantLoop - Given two loops pick the one that's most relevant for 605087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// SCEV expansion. If they are nested, this is the most nested. If they are 606087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// neighboring, pick the later. 607087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanstatic const Loop *PickMostRelevantLoop(const Loop *A, const Loop *B, 608087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT) { 609087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!A) return B; 610087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!B) return A; 611087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (A->contains(B)) return B; 612087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (B->contains(A)) return A; 613087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(A->getHeader(), B->getHeader())) return B; 614087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(B->getHeader(), A->getHeader())) return A; 615087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return A; // Arbitrarily break the tie. 616087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 617087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 6189c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman/// getRelevantLoop - Get the most relevant loop associated with the given 619087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// expression, according to PickMostRelevantLoop. 6209c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohmanconst Loop *SCEVExpander::getRelevantLoop(const SCEV *S) { 6219c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // Test whether we've already computed the most relevant loop for this SCEV. 6229c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman std::pair<DenseMap<const SCEV *, const Loop *>::iterator, bool> Pair = 6239c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman RelevantLoops.insert(std::make_pair(S, static_cast<const Loop *>(0))); 6249c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (!Pair.second) 6259c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return Pair.first->second; 6269c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman 627087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<SCEVConstant>(S)) 6289c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // A constant has no relevant loops. 629087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 630087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) { 631087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const Instruction *I = dyn_cast<Instruction>(U->getValue())) 6329c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return Pair.first->second = SE.LI->getLoopFor(I->getParent()); 6339c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // A non-instruction has no relevant loops. 634087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 635087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 636087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVNAryExpr *N = dyn_cast<SCEVNAryExpr>(S)) { 637087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *L = 0; 638087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) 639087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman L = AR->getLoop(); 640087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SCEVNAryExpr::op_iterator I = N->op_begin(), E = N->op_end(); 641087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I != E; ++I) 6429c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman L = PickMostRelevantLoop(L, getRelevantLoop(*I), *SE.DT); 6439c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[N] = L; 6449c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman } 6459c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(S)) { 6469c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman const Loop *Result = getRelevantLoop(C->getOperand()); 6479c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[C] = Result; 6489c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman } 6499c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (const SCEVUDivExpr *D = dyn_cast<SCEVUDivExpr>(S)) { 6509c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman const Loop *Result = 6519c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman PickMostRelevantLoop(getRelevantLoop(D->getLHS()), 6529c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman getRelevantLoop(D->getRHS()), 6539c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman *SE.DT); 6549c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[D] = Result; 655087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 656087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman llvm_unreachable("Unexpected SCEV type!"); 6579c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return 0; 658087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 659c4f7ec85ecb760fff2b702c6deb06506b968ba4fDan Gohman 660b35798347ea87b8b6d36155b211016a7769f01abDan Gohmannamespace { 661b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 662087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// LoopCompare - Compare loops by PickMostRelevantLoop. 663087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanclass LoopCompare { 664087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT; 665087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanpublic: 666087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman explicit LoopCompare(DominatorTree &dt) : DT(dt) {} 667087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 668087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool operator()(std::pair<const Loop *, const SCEV *> LHS, 669087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::pair<const Loop *, const SCEV *> RHS) const { 670bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // Keep pointer operands sorted at the end. 671bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (LHS.second->getType()->isPointerTy() != 672bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman RHS.second->getType()->isPointerTy()) 673bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman return LHS.second->getType()->isPointerTy(); 674bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman 675087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Compare loops with PickMostRelevantLoop. 676087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (LHS.first != RHS.first) 677087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return PickMostRelevantLoop(LHS.first, RHS.first, DT) != LHS.first; 678087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 679087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // If one operand is a non-constant negative and the other is not, 680087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // put the non-constant negative on the right so that a sub can 681087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // be used instead of a negate and add. 682087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isNonConstantNegative(LHS.second)) { 683087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!isNonConstantNegative(RHS.second)) 684087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 685087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (isNonConstantNegative(RHS.second)) 686087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return true; 687087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 688087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Otherwise they are equivalent according to this comparison. 689087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 690c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 691087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman}; 6925be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 693b35798347ea87b8b6d36155b211016a7769f01abDan Gohman} 694b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 695087bd1e3a12893873761736bf0f905a350e9e708Dan GohmanValue *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { 696db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 697e24fa64d52330626553298f56ba5aa702624c282Dan Gohman 698087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the add operands in a loop, along with their associated loops. 699087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal, and 700087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // so that pointer operands are inserted first, which the code below relies on 701087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // to form more involved GEPs. 702087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 703087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVAddExpr::op_iterator> I(S->op_end()), 704087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 7059c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I)); 706087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 707087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants and 708087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // pointer operands precede non-pointer operands. 709087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 710087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 711087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to add all the operands. Hoist as much as possible 712087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops, and form meaningful getelementptrs where possible. 713087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Sum = 0; 714087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 715087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 716087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *CurLoop = I->first; 717087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 718087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Sum) { 719087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 720087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expand(Op); 721087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 722db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner } else if (PointerType *PTy = dyn_cast<PointerType>(Sum->getType())) { 723087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum expression is a pointer. Try to form a getelementptr 724087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // at this level with that as the base. 725087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 726bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman for (; I != E && I->first == CurLoop; ++I) { 727bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // If the operand is SCEVUnknown and not instructions, peek through 728bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // it, to enable more of it to be folded into the GEP. 729bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman const SCEV *X = I->second; 730bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(X)) 731bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (!isa<Instruction>(U->getValue())) 732bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman X = SE.getSCEV(U->getValue()); 733bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman NewOps.push_back(X); 734bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman } 735087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum); 736db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner } else if (PointerType *PTy = dyn_cast<PointerType>(Op->getType())) { 737087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum is an integer, and there's a pointer at this level. 738f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // Try to form a getelementptr. If the running sum is instructions, 739f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // use a SCEVUnknown to avoid re-analyzing them. 740087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 741f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman NewOps.push_back(isa<Instruction>(Sum) ? SE.getUnknown(Sum) : 742f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman SE.getSCEV(Sum)); 743087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (++I; I != E && I->first == CurLoop; ++I) 744087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman NewOps.push_back(I->second); 745087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, expand(Op)); 746087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (isNonConstantNegative(Op)) { 747087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a negate and add, just do a subtract. 748a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(SE.getNegativeSCEV(Op), Ty); 749087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 750087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Sub, Sum, W); 751087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 752a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 753087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple add. 754a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(Op, Ty); 755087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 756087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 757087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Sum)) std::swap(Sum, W); 758087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Add, Sum, W); 759087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 760a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 7612d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 762087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 763087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Sum; 764e24fa64d52330626553298f56ba5aa702624c282Dan Gohman} 7655be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 766890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) { 767db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 768087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 769087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the mul operands in a loop, along with their associated loops. 770087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal. 771087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 772087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVMulExpr::op_iterator> I(S->op_end()), 773087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 7749c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I)); 775087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 776087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants. 777087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 778087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 779087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to mul all the operands. Hoist as much as possible 780087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops. 781087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Prod = 0; 782087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 783087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 784087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 785087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Prod) { 786087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 787087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = expand(Op); 788087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 789087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (Op->isAllOnesValue()) { 790087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a multiply by negative one, just do a negate. 791087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 792087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Sub, Constant::getNullValue(Ty), Prod); 793087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 794087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else { 795087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple mul. 796087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *W = expandCodeFor(Op, Ty); 797087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 798087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 799087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Prod)) std::swap(Prod, W); 800087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Mul, Prod, W); 801087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 802087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 8032d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 8042d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 805087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Prod; 80636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 80736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 808890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) { 809db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 8102d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 81192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *LHS = expandCodeFor(S->getLHS(), Ty); 812890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getRHS())) { 8136177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky const APInt &RHS = SC->getValue()->getValue(); 8146177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky if (RHS.isPowerOf2()) 8156177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky return InsertBinop(Instruction::LShr, LHS, 816eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson ConstantInt::get(Ty, RHS.logBase2())); 8176177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky } 8186177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 81992fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getRHS(), Ty); 820267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman return InsertBinop(Instruction::UDiv, LHS, RHS); 8216177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky} 8226177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 823453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Move parts of Base into Rest to leave Base with the minimal 824453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// expression that provides a pointer operand suitable for a 825453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEP expansion. 8260bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic void ExposePointerBase(const SCEV *&Base, const SCEV *&Rest, 827453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ScalarEvolution &SE) { 828453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Base)) { 829453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getStart(); 830453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(Rest, 831deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getAddRecExpr(SE.getConstant(A->getType(), 0), 832453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getStepRecurrence(SE), 8333228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick A->getLoop(), 8343228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: A->getNoWrapFlags(FlagNW) 8353228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 836453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 837453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(Base)) { 838453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getOperand(A->getNumOperands()-1); 8390bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> NewAddOps(A->op_begin(), A->op_end()); 840453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman NewAddOps.back() = Rest; 841453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(NewAddOps); 842453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ExposePointerBase(Base, Rest, SE); 843453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 844453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 845453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 846a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// getAddRecExprPHILiterally - Helper for expandAddRecExprLiterally. Expand 847a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// the base addrec, which is the addrec without any non-loop-dominating 848a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// values, and return the PHI. 849a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanPHINode * 850a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanSCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized, 851a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L, 852db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ExpandTy, 853db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntTy) { 85493a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer assert((!IVIncInsertLoop||IVIncInsertPos) && "Uninitialized insert position"); 855d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 856a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Reuse a previously-inserted PHI, if present. 857a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman for (BasicBlock::iterator I = L->getHeader()->begin(); 858a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = dyn_cast<PHINode>(I); ++I) 859572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman if (SE.isSCEVable(PN->getType()) && 860572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman (SE.getEffectiveSCEVType(PN->getType()) == 861572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman SE.getEffectiveSCEVType(Normalized->getType())) && 862572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman SE.getSCEV(PN) == Normalized) 863572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman if (BasicBlock *LatchBlock = L->getLoopLatch()) { 864572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman Instruction *IncV = 86522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)); 86622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman 86722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Determine if this is a well-behaved chain of instructions leading 86822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // back to the PHI. It probably will be, if we're scanning an inner 86922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // loop already visited by LSR for example, but it wouldn't have 87022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // to be. 87122e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman do { 8720cbe91ba3bd84a5ef68a1d0de5df6e955690b0a4Dan Gohman if (IncV->getNumOperands() == 0 || isa<PHINode>(IncV) || 873a7a841adb89efa6ad3b35e9d4bcccccfb8ca146aDan Gohman (isa<CastInst>(IncV) && !isa<BitCastInst>(IncV))) { 87422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = 0; 87522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 87622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } 8779feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // If any of the operands don't dominate the insert position, bail. 8789feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // Addrec operands are always loop-invariant, so this can only happen 8799feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // if there are instructions which haven't been hoisted. 880d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick if (L == IVIncInsertLoop) { 881d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick for (User::op_iterator OI = IncV->op_begin()+1, 882d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick OE = IncV->op_end(); OI != OE; ++OI) 883d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick if (Instruction *OInst = dyn_cast<Instruction>(OI)) 884d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick if (!SE.DT->dominates(OInst, IVIncInsertPos)) { 885d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick IncV = 0; 886d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick break; 887d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick } 888d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick } 8899feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman if (!IncV) 8909feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman break; 8919feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // Advance to the next instruction. 89222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 89322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (!IncV) 89422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 89522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (IncV->mayHaveSideEffects()) { 89622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = 0; 89722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 89822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } 89922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } while (IncV != PN); 90022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman 90122e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (IncV) { 90222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Ok, the add recurrence looks usable. 90322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Remember this PHI, even in post-inc mode. 90422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman InsertedValues.insert(PN); 90522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Remember the increment. 90622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)); 90722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman rememberInstruction(IncV); 90822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (L == IVIncInsertLoop) 90922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman do { 91022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (SE.DT->dominates(IncV, IVIncInsertPos)) 91122e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 91222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Make sure the increment is where we want it. But don't move it 91322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // down past a potential existing post-inc user. 91422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV->moveBefore(IVIncInsertPos); 91522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IVIncInsertPos = IncV; 91622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = cast<Instruction>(IncV->getOperand(0)); 91722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } while (IncV != PN); 91822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman return PN; 91922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } 920572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman } 921a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 922a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Save the original insertion point so we can restore it when we're done. 923a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 924a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 925a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 926a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the start value. 927a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StartV = expandCodeFor(Normalized->getStart(), ExpandTy, 928a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman L->getHeader()->begin()); 929a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 930d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick // StartV must be hoisted into L's preheader to dominate the new phi. 93193a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer assert(!isa<Instruction>(StartV) || 93293a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer SE.DT->properlyDominates(cast<Instruction>(StartV)->getParent(), 93393a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer L->getHeader())); 934d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 935a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the step value. Insert instructions right before the 936a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // terminator corresponding to the back-edge. Do this before creating the PHI 937a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // so that PHI reuse code doesn't see an incomplete PHI. If the stride is 938a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // negative, insert a sub instead of an add for the increment (unless it's a 939a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // constant, because subtracts of constants are canonicalized to adds). 940a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 9411df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands bool isPointer = ExpandTy->isPointerTy(); 942a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman bool isNegative = !isPointer && isNonConstantNegative(Step); 943a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (isNegative) 944a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Step = SE.getNegativeSCEV(Step); 945a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StepV = expandCodeFor(Step, IntTy, L->getHeader()->begin()); 946a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 947a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the PHI. 948d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad BasicBlock *Header = L->getHeader(); 949d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad Builder.SetInsertPoint(Header, Header->begin()); 950d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad pred_iterator HPB = pred_begin(Header), HPE = pred_end(Header); 9515e7645be4c9dd2193add44d30b5fef8036d7a3ceAndrew Trick PHINode *PN = Builder.CreatePHI(ExpandTy, std::distance(HPB, HPE), 952dc8e546048db2f7ff5656742b2b26975098a11a0Andrew Trick Twine(IVName) + ".iv"); 953a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(PN); 954a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 955a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the step instructions and populate the PHI. 956d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad for (pred_iterator HPI = HPB; HPI != HPE; ++HPI) { 957a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *Pred = *HPI; 958a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 959a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Add a start value. 960a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!L->contains(Pred)) { 961a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(StartV, Pred); 962a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman continue; 963a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 964a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 965a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create a step value and add it to the PHI. If IVIncInsertLoop is 966a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // non-null and equal to the addrec's loop, insert the instructions 967a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // at IVIncInsertPos. 968a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Instruction *InsertPos = L == IVIncInsertLoop ? 969a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IVIncInsertPos : Pred->getTerminator(); 970c5ecbdc1896f1cc089372feef3191ace2f840898Devang Patel Builder.SetInsertPoint(InsertPos); 971a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *IncV; 972a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If the PHI is a pointer, use a GEP, otherwise use an add or sub. 973a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (isPointer) { 974db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner PointerType *GEPPtrTy = cast<PointerType>(ExpandTy); 975a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If the step isn't constant, don't use an implicitly scaled GEP, because 976a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // that would require a multiply inside the loop. 977a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!isa<ConstantInt>(StepV)) 978a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman GEPPtrTy = PointerType::get(Type::getInt1Ty(SE.getContext()), 979a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman GEPPtrTy->getAddressSpace()); 980a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const StepArray[1] = { SE.getSCEV(StepV) }; 981a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = expandAddToGEP(StepArray, StepArray+1, GEPPtrTy, IntTy, PN); 982a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (IncV->getType() != PN->getType()) { 983a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = Builder.CreateBitCast(IncV, PN->getType(), "tmp"); 984a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(IncV); 985a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 986a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 987a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = isNegative ? 988dc8e546048db2f7ff5656742b2b26975098a11a0Andrew Trick Builder.CreateSub(PN, StepV, Twine(IVName) + ".iv.next") : 989dc8e546048db2f7ff5656742b2b26975098a11a0Andrew Trick Builder.CreateAdd(PN, StepV, Twine(IVName) + ".iv.next"); 990a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(IncV); 991a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 992a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(IncV, Pred); 993a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 994a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 995a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Restore the original insert point. 996a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (SaveInsertBB) 997455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 998a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 999a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Remember this PHI, even in post-inc mode. 1000a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman InsertedValues.insert(PN); 1001a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1002a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return PN; 1003a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1004a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1005a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanValue *SCEVExpander::expandAddRecExprLiterally(const SCEVAddRecExpr *S) { 1006db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *STy = S->getType(); 1007db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntTy = SE.getEffectiveSCEVType(STy); 1008a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L = S->getLoop(); 1009a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1010a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Determine a normalized form of this expression, which is the expression 1011a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // before any post-inc adjustment is made. 1012a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVAddRecExpr *Normalized = S; 1013448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (PostIncLoops.count(L)) { 1014448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman PostIncLoopSet Loops; 1015448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops.insert(L); 1016448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Normalized = 1017448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman cast<SCEVAddRecExpr>(TransformForPostIncUse(Normalize, S, 0, 0, 1018448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops, SE, *SE.DT)); 1019a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1020a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1021a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec start. 1022a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Start = Normalized->getStart(); 1023a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopOffset = 0; 1024dc0e8fb9f9512622f55f73e1a434caa5c0915694Dan Gohman if (!SE.properlyDominates(Start, L->getHeader())) { 1025a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopOffset = Start; 1026deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Start = SE.getConstant(Normalized->getType(), 0); 10273228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized = cast<SCEVAddRecExpr>( 10283228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SE.getAddRecExpr(Start, Normalized->getStepRecurrence(SE), 10293228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized->getLoop(), 10303228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: Normalized->getNoWrapFlags(FlagNW) 10313228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1032a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1033a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1034a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec step. 1035a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 1036a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopScale = 0; 1037dc0e8fb9f9512622f55f73e1a434caa5c0915694Dan Gohman if (!SE.dominates(Step, L->getHeader())) { 1038a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopScale = Step; 1039deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Step = SE.getConstant(Normalized->getType(), 1); 1040a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized = 1041a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start, Step, 10423228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized->getLoop(), 10433228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: Normalized 10443228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // ->getNoWrapFlags(FlagNW) 10453228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1046a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1047a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1048a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand the core addrec. If we need post-loop scaling, force it to 1049a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // expand to an integer type to avoid the need for additional casting. 1050db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ExpandTy = PostLoopScale ? IntTy : STy; 1051a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = getAddRecExprPHILiterally(Normalized, L, ExpandTy, IntTy); 1052a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 10533f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // Accommodate post-inc mode, if necessary. 1054a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Result; 1055448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (!PostIncLoops.count(L)) 1056a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN; 1057a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman else { 1058a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // In PostInc mode, use the post-incremented value. 1059a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *LatchBlock = L->getLoopLatch(); 1060a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman assert(LatchBlock && "PostInc mode requires a unique loop latch!"); 1061a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN->getIncomingValueForBlock(LatchBlock); 1062a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1063a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1064a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating scale. 1065a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopScale) { 10660a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1067a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateMul(Result, 1068a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopScale, IntTy)); 1069a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1070a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1071a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1072a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating offset. 1073a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopOffset) { 1074db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (PointerType *PTy = dyn_cast<PointerType>(ExpandTy)) { 1075a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const OffsetArray[1] = { PostLoopOffset }; 1076a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = expandAddToGEP(OffsetArray, OffsetArray+1, PTy, IntTy, Result); 1077a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 10780a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1079a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateAdd(Result, 1080a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopOffset, IntTy)); 1081a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1082a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1083a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1084a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1085a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return Result; 1086a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1087a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1088890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { 1089a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!CanonicalMode) return expandAddRecExprLiterally(S); 1090a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1091db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 109236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Loop *L = S->getLoop(); 109336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 10944d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // First check for an existing canonical IV in a suitable type. 10954d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman PHINode *CanonicalIV = 0; 10964d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (PHINode *PN = L->getCanonicalInductionVariable()) 1097133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman if (SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty)) 10984d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV = PN; 10994d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 11004d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Rewrite an AddRec in terms of the canonical induction variable, if 11014d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // its type is more narrow. 11024d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (CanonicalIV && 11034d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(CanonicalIV->getType()) > 11044d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(Ty)) { 1105f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->getNumOperands()); 1106f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman for (unsigned i = 0, e = S->getNumOperands(); i != e; ++i) 1107f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman NewOps[i] = SE.getAnyExtendExpr(S->op_begin()[i], CanonicalIV->getType()); 11083228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Value *V = expand(SE.getAddRecExpr(NewOps, S->getLoop(), 11093228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: S->getNoWrapFlags(FlagNW) 11103228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1111267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1112267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 11134d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman BasicBlock::iterator NewInsertPt = 11147896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner llvm::next(BasicBlock::iterator(cast<Instruction>(V))); 1115a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling while (isa<PHINode>(NewInsertPt) || isa<DbgInfoIntrinsic>(NewInsertPt) || 1116a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(NewInsertPt)) 111708f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach ++NewInsertPt; 11184d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), 0, 11194d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewInsertPt); 1120455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 11214d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman return V; 11224d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman } 11234d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 112436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {X,+,F} --> X + {0,+,F} 1125cfeb6a450632f2a6cd05302633c8c2b8c90cfdfdDan Gohman if (!S->getStart()->isZero()) { 1126f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->op_begin(), S->op_end()); 1127deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman NewOps[0] = SE.getConstant(Ty, 0); 11283228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: can use S->getNoWrapFlags() 11293228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick const SCEV *Rest = SE.getAddRecExpr(NewOps, L, SCEV::FlagAnyWrap); 1130453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 1131453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the 1132453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // comments on expandAddToGEP for details. 1133c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Base = S->getStart(); 1134c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *RestArray[1] = { Rest }; 1135c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Dig into the expression to find the pointer base for a GEP. 1136c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ExposePointerBase(Base, RestArray[0], SE); 1137c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If we found a pointer, expand the AddRec with a GEP. 1138db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (PointerType *PTy = dyn_cast<PointerType>(Base->getType())) { 1139c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Make sure the Base isn't something exotic, such as a multiplied 1140c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // or divided pointer value. In those cases, the result type isn't 1141c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // actually a pointer type. 1142c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!isa<SCEVMulExpr>(Base) && !isa<SCEVUDivExpr>(Base)) { 1143c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *StartV = expand(Base); 1144c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman assert(StartV->getType() == PTy && "Pointer type mismatch for GEP!"); 1145c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return expandAddToGEP(RestArray, RestArray+1, PTy, Ty, StartV); 1146453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1147453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1148453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 114940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Just do a normal add. Pre-expand the operands to suppress folding. 115040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return expand(SE.getAddExpr(SE.getUnknown(expand(S->getStart())), 115140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getUnknown(expand(Rest)))); 115236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 115336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11546ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // If we don't yet have a canonical IV, create one. 11556ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (!CanonicalIV) { 115636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Create and insert the PHI node for the induction variable in the 115736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // specified loop. 115836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman BasicBlock *Header = L->getHeader(); 1159d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad pred_iterator HPB = pred_begin(Header), HPE = pred_end(Header); 11603ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad CanonicalIV = PHINode::Create(Ty, std::distance(HPB, HPE), "indvar", 11613ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad Header->begin()); 11626ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman rememberInstruction(CanonicalIV); 116336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1164eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Constant *One = ConstantInt::get(Ty, 1); 1165d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad for (pred_iterator HPI = HPB; HPI != HPE; ++HPI) { 11667656018c2268285907cfdc106071462a01a73878Gabor Greif BasicBlock *HP = *HPI; 11677656018c2268285907cfdc106071462a01a73878Gabor Greif if (L->contains(HP)) { 11683abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // Insert a unit add instruction right before the terminator 11693abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // corresponding to the back-edge. 11706ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman Instruction *Add = BinaryOperator::CreateAdd(CanonicalIV, One, 11716ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "indvar.next", 11726ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman HP->getTerminator()); 1173df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel Add->setDebugLoc(HP->getTerminator()->getDebugLoc()); 1174a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Add); 11756ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Add, HP); 117683d577490b1473213b6973236110c28e59127956Dan Gohman } else { 11776ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Constant::getNullValue(Ty), HP); 117883d577490b1473213b6973236110c28e59127956Dan Gohman } 11797656018c2268285907cfdc106071462a01a73878Gabor Greif } 118036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 118136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11826ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // {0,+,1} --> Insert a canonical induction variable into the loop! 11836ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (S->isAffine() && S->getOperand(1)->isOne()) { 11846ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) && 11856ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "IVs with types different from the canonical IV should " 11866ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "already have been handled!"); 11876ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman return CanonicalIV; 11886ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman } 11896ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman 11904d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // {0,+,F} --> {0,+,1} * F 119136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1192df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If this is a simple linear addrec, emit it now as a special case. 119340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (S->isAffine()) // {0,+,F} --> i*F 119440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return 119540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman expand(SE.getTruncateOrNoop( 11966ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman SE.getMulExpr(SE.getUnknown(CanonicalIV), 119740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getNoopOrAnyExtend(S->getOperand(1), 11986ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->getType())), 119940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Ty)); 120036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 120136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // If this is a chain of recurrences, turn it into a closed form, using the 120236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // folders, then expandCodeFor the closed form. This allows the folders to 120336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // simplify the expression without having to build a bunch of special code 120436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // into this folder. 12056ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *IH = SE.getUnknown(CanonicalIV); // Get I as a "symbolic" SCEV. 120636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12074d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Promote S up to the canonical IV type, if the cast is foldable. 12080bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *NewS = S; 12096ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *Ext = SE.getNoopOrAnyExtend(S, CanonicalIV->getType()); 12104d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (isa<SCEVAddRecExpr>(Ext)) 12114d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewS = Ext; 12124d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 12130bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE); 1214e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; 121536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12164d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Truncate the result down to the original type, if needed. 12170bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *T = SE.getTruncateOrNoop(V, Ty); 1218469f3cdc13851914f3a766cbd8f701cf8431cacaDan Gohman return expand(T); 121936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 122096fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 1221890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitTruncateExpr(const SCEVTruncateExpr *S) { 1222db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 122392fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 122492fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1225267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateTrunc(V, Ty, "tmp"); 1226a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1227cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 122811f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 122911f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1230890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitZeroExtendExpr(const SCEVZeroExtendExpr *S) { 1231db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 123292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 123392fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1234267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateZExt(V, Ty, "tmp"); 1235a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1236cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 123711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 123811f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1239890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) { 1240db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 124192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 124292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1243267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateSExt(V, Ty, "tmp"); 1244a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1245cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 124611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 124711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1248890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { 12490196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 1250db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = LHS->getType(); 12510196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 12520196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 12530196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 12540196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 12550196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 12560196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 12570196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 125892fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1259267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *ICmp = Builder.CreateICmpSGT(LHS, RHS, "tmp"); 1260a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1261267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "smax"); 1262a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1263cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 1264c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky } 12650196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 12660196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 12670196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 12680196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 1269c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky return LHS; 1270c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky} 1271c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky 1272890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { 12730196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 1274db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = LHS->getType(); 12750196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 12760196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 12770196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 12780196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 12790196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 12800196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 12810196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 128292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1283267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *ICmp = Builder.CreateICmpUGT(LHS, RHS, "tmp"); 1284a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1285267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "umax"); 1286a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1287cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 12883e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky } 12890196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 12900196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 12910196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 12920196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 12933e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky return LHS; 12943e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky} 12953e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky 1296db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::expandCodeFor(const SCEV *SH, Type *Ty, 12976c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Instruction *I) { 12986c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman BasicBlock::iterator IP = I; 12996c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(IP) || isa<DbgInfoIntrinsic>(IP)) 13006c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman ++IP; 13016c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Builder.SetInsertPoint(IP->getParent(), IP); 13026c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman return expandCodeFor(SH, Ty); 13036c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman} 13046c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman 1305db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::expandCodeFor(const SCEV *SH, Type *Ty) { 130611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman // Expand the code for this SCEV. 13072d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *V = expand(SH); 13085be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Ty) { 13095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman assert(SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(SH->getType()) && 13105be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman "non-trivial casts should be done with the SCEVs directly!"); 13115be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, Ty); 13125be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 13135be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return V; 131411f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 131511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1316890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::expand(const SCEV *S) { 131740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Compute an insertion point for this SCEV object. Hoist the instructions 131840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // as far out in the loop nest as possible. 1319267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *InsertPt = Builder.GetInsertPoint(); 1320267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman for (Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock()); ; 132140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman L = L->getParentLoop()) 132217ead4ff4baceb2c5503f233d0288d363ae44165Dan Gohman if (SE.isLoopInvariant(S, L)) { 132340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (!L) break; 1324e059ee832ca36d65a5fb87b0ac5bcdb0490b15cbDan Gohman if (BasicBlock *Preheader = L->getLoopPreheader()) 132540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = Preheader->getTerminator(); 132640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } else { 132740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // If the SCEV is computable at this level, insert it into the header 132840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // after the PHIs (and after any other instructions that we've inserted 132940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // there) so that it is guaranteed to dominate any user inside the loop. 13305b6f42f57e730c2d968c313a27fa505a3c3e5efaBill Wendling if (L && SE.hasComputableLoopEvolution(S, L) && !PostIncLoops.count(L)) 13315b6f42f57e730c2d968c313a27fa505a3c3e5efaBill Wendling InsertPt = L->getHeader()->getFirstInsertionPt(); 13326c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(InsertPt) || isa<DbgInfoIntrinsic>(InsertPt)) 13337896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner InsertPt = llvm::next(BasicBlock::iterator(InsertPt)); 133440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman break; 133540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } 133640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1337667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Check to see if we already expanded this here. 1338667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman std::map<std::pair<const SCEV *, Instruction *>, 1339667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman AssertingVH<Value> >::iterator I = 1340667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman InsertedExpressions.find(std::make_pair(S, InsertPt)); 1341267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (I != InsertedExpressions.end()) 1342667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman return I->second; 1343267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 1344267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1345267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1346267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(InsertPt->getParent(), InsertPt); 1347667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1348667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Expand the expression into instructions. 134996fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov Value *V = visit(S); 135040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1351667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Remember the expanded value for this SCEV at this location. 1352448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (PostIncLoops.empty()) 1353a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman InsertedExpressions[std::make_pair(S, InsertPt)] = V; 1354667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1355455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 135696fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return V; 135796fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov} 13581d09de3eca23267855e28297fcb40de3632ea47bDan Gohman 13591d826a76f591afea445489b9a5485c345e66bf87Dan Gohmanvoid SCEVExpander::rememberInstruction(Value *I) { 136025fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman if (!PostIncLoops.empty()) 136125fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman InsertedPostIncValues.insert(I); 136225fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman else 13631d826a76f591afea445489b9a5485c345e66bf87Dan Gohman InsertedValues.insert(I); 13641d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 13651d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // If we just claimed an existing instruction and that instruction had 13663228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // been the insert point, adjust the insert point forward so that 13671d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // subsequently inserted code will be dominated. 13681d826a76f591afea445489b9a5485c345e66bf87Dan Gohman if (Builder.GetInsertPoint() == I) { 13691d826a76f591afea445489b9a5485c345e66bf87Dan Gohman BasicBlock::iterator It = cast<Instruction>(I); 13706c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman do { ++It; } while (isInsertedInstruction(It) || 13716c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman isa<DbgInfoIntrinsic>(It)); 13721d826a76f591afea445489b9a5485c345e66bf87Dan Gohman Builder.SetInsertPoint(Builder.GetInsertBlock(), It); 13731d826a76f591afea445489b9a5485c345e66bf87Dan Gohman } 13741d826a76f591afea445489b9a5485c345e66bf87Dan Gohman} 13751d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 1376455985501381777db03534c925a35e261e356395Dan Gohmanvoid SCEVExpander::restoreInsertPoint(BasicBlock *BB, BasicBlock::iterator I) { 13773f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If we acquired more instructions since the old insert point was saved, 1378455985501381777db03534c925a35e261e356395Dan Gohman // advance past them. 13796c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(I) || isa<DbgInfoIntrinsic>(I)) ++I; 1380455985501381777db03534c925a35e261e356395Dan Gohman 1381455985501381777db03534c925a35e261e356395Dan Gohman Builder.SetInsertPoint(BB, I); 1382455985501381777db03534c925a35e261e356395Dan Gohman} 1383455985501381777db03534c925a35e261e356395Dan Gohman 13841d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// getOrInsertCanonicalInductionVariable - This method returns the 13851d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// canonical induction variable of the specified type for the specified 13861d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// loop (inserting one if there is none). A canonical induction variable 13871d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// starts at zero and steps by one on each iteration. 13887c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan GohmanPHINode * 13891d09de3eca23267855e28297fcb40de3632ea47bDan GohmanSCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L, 1390db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty) { 1391b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands assert(Ty->isIntegerTy() && "Can only insert integer induction variables!"); 1392133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1393133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Build a SCEV for {0,+,1}<L>. 13943228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // Conservatively use FlagAnyWrap for now. 1395deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *H = SE.getAddRecExpr(SE.getConstant(Ty, 0), 13963228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SE.getConstant(Ty, 1), L, SCEV::FlagAnyWrap); 1397133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1398133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Emit code for it. 1399267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1400267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 14017c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan Gohman PHINode *V = cast<PHINode>(expandCodeFor(H, 0, L->getHeader()->begin())); 1402267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (SaveInsertBB) 1403455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1404133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 140540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return V; 14061d09de3eca23267855e28297fcb40de3632ea47bDan Gohman} 1407