ScalarEvolutionExpander.cpp revision 48ba0e45ed68689ce7b384578e6272410e4e23fe
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" 20c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick#include "llvm/Support/Debug.h" 215be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman#include "llvm/Target/TargetData.h" 224d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman#include "llvm/ADT/STLExtras.h" 23d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 2436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begemanusing namespace llvm; 2536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 2619e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif/// ReuseOrCreateCast - Arrange for there to be a cast of V to Ty at IP, 27485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// reusing an existing cast if a suitable one exists, moving an existing 28485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// cast if a suitable one exists but isn't in the right place, or 2919e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif/// creating a new one. 30db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::ReuseOrCreateCast(Value *V, Type *Ty, 31485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction::CastOps Op, 32485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP) { 33485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Check to see if there is already a cast! 34485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); 35f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif UI != E; ++UI) { 36f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif User *U = *UI; 37f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif if (U->getType() == Ty) 3819e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif if (CastInst *CI = dyn_cast<CastInst>(U)) 39485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (CI->getOpcode() == Op) { 40485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // If the cast isn't where we want it, fix it. 41485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (BasicBlock::iterator(CI) != IP) { 42485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast, and leave the old cast in place in case 43485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // it is being used as an insert point. Clear its operand 44485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // so that it doesn't hold anything live. 45485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *NewCI = CastInst::Create(Op, V, Ty, "", IP); 46485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman NewCI->takeName(CI); 47485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->replaceAllUsesWith(NewCI); 48485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->setOperand(0, UndefValue::get(V->getType())); 49485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(NewCI); 50485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return NewCI; 51485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 526f5fed253f58645bf45448893a585ffbd9914989Dan Gohman rememberInstruction(CI); 53485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return CI; 54485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 55f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif } 56485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 57485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast. 58485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *I = CastInst::Create(Op, V, Ty, V->getName(), IP); 59485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(I); 60485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return I; 61485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman} 62485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 63267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// InsertNoopCastOfTo - Insert a cast of V to the specified type, 64267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// which must be possible with a noop cast, doing what we can to share 65267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// the casts. 66db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::InsertNoopCastOfTo(Value *V, Type *Ty) { 67267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction::CastOps Op = CastInst::getCastOpcode(V, false, Ty, false); 68267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert((Op == Instruction::BitCast || 69267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::PtrToInt || 70267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::IntToPtr) && 71267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot perform non-noop casts!"); 72267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert(SE.getTypeSizeInBits(V->getType()) == SE.getTypeSizeInBits(Ty) && 73267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot change sizes!"); 74267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 752d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman // Short-circuit unnecessary bitcasts. 76267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (Op == Instruction::BitCast && V->getType() == Ty) 772d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman return V; 782d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 79f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman // Short-circuit unnecessary inttoptr<->ptrtoint casts. 80267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if ((Op == Instruction::PtrToInt || Op == Instruction::IntToPtr) && 8180dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) { 82af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if (CastInst *CI = dyn_cast<CastInst>(V)) 83af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if ((CI->getOpcode() == Instruction::PtrToInt || 84af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman CI->getOpcode() == Instruction::IntToPtr) && 85af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getType()) == 86af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getOperand(0)->getType())) 87af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return CI->getOperand(0); 8880dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 8980dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if ((CE->getOpcode() == Instruction::PtrToInt || 9080dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman CE->getOpcode() == Instruction::IntToPtr) && 9180dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getType()) == 9280dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getOperand(0)->getType())) 9380dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman return CE->getOperand(0); 9480dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman } 95f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman 96485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Fold a cast of a constant. 97ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 98baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Op, C, Ty); 994c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman 100485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the argument at the beginning of the entry block, after 101485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // any bitcasts of other arguments. 102ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Argument *A = dyn_cast<Argument>(V)) { 103485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP = A->getParent()->getEntryBlock().begin(); 104485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman while ((isa<BitCastInst>(IP) && 105485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman isa<Argument>(cast<BitCastInst>(IP)->getOperand(0)) && 106485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman cast<BitCastInst>(IP)->getOperand(0) != A) || 107a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<DbgInfoIntrinsic>(IP) || 108a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(IP)) 109485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman ++IP; 110485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(A, Ty, Op, IP); 111ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 1123913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 113485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the instruction immediately after the instruction. 114ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner Instruction *I = cast<Instruction>(V); 115ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner BasicBlock::iterator IP = I; ++IP; 116ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(I)) 117ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner IP = II->getNormalDest()->begin(); 118a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling while (isa<PHINode>(IP) || isa<DbgInfoIntrinsic>(IP) || 119a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(IP)) 120a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling ++IP; 121485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(I, Ty, Op, IP); 122ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner} 123ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 1247fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// InsertBinop - Insert the specified binary operator, doing a small amount 1257fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// of work to avoid inserting an obviously redundant operation. 126267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, 127267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *LHS, Value *RHS) { 1280f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman // Fold a binop with constant operands. 1290f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(LHS)) 1300f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(RHS)) 131baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, CLHS, CRHS); 1320f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman 1337fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner // Do a quick scan to see if we have this binop nearby. If so, reuse it. 1347fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner unsigned ScanLimit = 6; 135267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 136267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 137267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 138267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 1398a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz --IP; 1408a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz for (; ScanLimit; --IP, --ScanLimit) { 1418d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 1428d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 1438d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 1448d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 1455be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == (unsigned)Opcode && IP->getOperand(0) == LHS && 1465be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(1) == RHS) 1475be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 1488a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (IP == BlockBegin) break; 1498a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz } 1507fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner } 151267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 152087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 153087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 154087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 155087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 156087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 157087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 158087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(LHS) || !L->isLoopInvariant(RHS)) break; 159087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 160087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 161087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 162087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 163087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 164087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 165087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 1668a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // If we haven't found this binop, insert it. 167a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Instruction *BO = cast<Instruction>(Builder.CreateBinOp(Opcode, LHS, RHS)); 168df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel BO->setDebugLoc(SaveInsertPt->getDebugLoc()); 169a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(BO); 170087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 171087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 172087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 173087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 174087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 175cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return BO; 1767fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner} 1777fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner 1784a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// FactorOutConstant - Test if S is divisible by Factor, using signed 179453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// division. If so, update S with Factor divided out and return true. 1803f46a3abeedba8d517b4182de34c821d752db058Dan Gohman/// S need not be evenly divisible if a reasonable remainder can be 1814a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// computed. 182453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// TODO: When ScalarEvolution gets a SCEVSDivExpr, this can be made 183453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// unnecessary; in its place, just signed-divide Ops[i] by the scale and 184453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// check to see if the divide was folded. 1850bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic bool FactorOutConstant(const SCEV *&S, 1860bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *&Remainder, 187c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Factor, 188c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE, 189c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const TargetData *TD) { 190453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Everything is divisible by one. 191c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Factor->isOne()) 192c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 193c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 194c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // x/x == 1. 195c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (S == Factor) { 196deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman S = SE.getConstant(S->getType(), 1); 197453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 198c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 199453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 200453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // For a Constant, check for a multiple of the given factor. 2014a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S)) { 202c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // 0/x == 0. 203c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (C->isZero()) 204453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 205c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Check for divisibility. 206c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *FC = dyn_cast<SCEVConstant>(Factor)) { 207c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt *CI = 208c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt::get(SE.getContext(), 209c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman C->getValue()->getValue().sdiv( 210c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 211c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the quotient is zero and the remainder is non-zero, reject 212c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the value at this scale. It will be considered for subsequent 213c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // smaller scales. 214c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!CI->isZero()) { 215c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Div = SE.getConstant(CI); 216c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = Div; 217c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder = 218c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(Remainder, 219c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().srem( 220c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue()))); 221c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 222c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 223453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 2244a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman } 225453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 226453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In a Mul, check if there is a constant operand which is a multiple 227453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // of the given factor. 228c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S)) { 229c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (TD) { 230c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, the size is known. Check if there is a constant 231c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // operand which is a multiple of the given factor. If so, we can 232c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // factor it. 233c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEVConstant *FC = cast<SCEVConstant>(Factor); 234c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0))) 235c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!C->getValue()->getValue().srem(FC->getValue()->getValue())) { 236f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 237c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[0] = 238c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().sdiv( 239c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 240c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 241c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 242c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 243c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 244c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Without TargetData, check if Factor can be factored out of any of the 245c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Mul's operands. If so, we can just remove it. 246c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) { 247c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *SOp = M->getOperand(i); 248deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(SOp->getType(), 0); 249c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (FactorOutConstant(SOp, Remainder, Factor, SE, TD) && 250c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder->isZero()) { 251f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 252c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[i] = SOp; 253c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 254c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 255c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 256453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 257c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 258c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 259453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 260453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In an AddRec, check if both start and step are divisible. 261453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(S)) { 2620bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Step = A->getStepRecurrence(SE); 263deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *StepRem = SE.getConstant(Step->getType(), 0); 264c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Step, StepRem, Factor, SE, TD)) 2654a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2664a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (!StepRem->isZero()) 2674a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2680bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Start = A->getStart(); 269c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Start, Remainder, Factor, SE, TD)) 270453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 2713228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: can use A->getNoWrapFlags(FlagNW) 2723228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick S = SE.getAddRecExpr(Start, Step, A->getLoop(), SCEV::FlagAnyWrap); 273453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 274453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 275453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 276453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 277453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 278453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 279c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SimplifyAddOperands - Sort and simplify a list of add operands. NumAddRecs 280c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// is the number of SCEVAddRecExprs present, which are kept at the end of 281c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// the list. 282c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 283c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SimplifyAddOperands(SmallVectorImpl<const SCEV *> &Ops, 284db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 285c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 286c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman unsigned NumAddRecs = 0; 287c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = Ops.size(); i > 0 && isa<SCEVAddRecExpr>(Ops[i-1]); --i) 288c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ++NumAddRecs; 289c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Group Ops into non-addrecs and addrecs. 290c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> NoAddRecs(Ops.begin(), Ops.end() - NumAddRecs); 291c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs(Ops.end() - NumAddRecs, Ops.end()); 292c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Let ScalarEvolution sort and simplify the non-addrecs list. 293c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Sum = NoAddRecs.empty() ? 294deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getConstant(Ty, 0) : 295c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(NoAddRecs); 296c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If it returned an add, use the operands. Otherwise it simplified 297c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the sum into a single value, so just use that. 298f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.clear(); 299c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Sum)) 300403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 301f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman else if (!Sum->isZero()) 302f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.push_back(Sum); 303c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Then append the addrecs. 304403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 305c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 306c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 307c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SplitAddRecs - Flatten a list of add operands, moving addrec start values 308c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// out to the top level. For example, convert {a + b,+,c} to a, b, {0,+,d}. 309c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// This helps expose more opportunities for folding parts of the expressions 310c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// into GEP indices. 311c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 312c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SplitAddRecs(SmallVectorImpl<const SCEV *> &Ops, 313db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 314c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 315c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Find the addrecs. 316c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs; 317c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 318c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) { 319c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Start = A->getStart(); 320c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Start->isZero()) break; 321deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Zero = SE.getConstant(Ty, 0); 322c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AddRecs.push_back(SE.getAddRecExpr(Zero, 323c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getStepRecurrence(SE), 3243228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick A->getLoop(), 3253228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: A->getNoWrapFlags(FlagNW) 3263228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 327c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Start)) { 328c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Zero; 329403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 330c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman e += Add->getNumOperands(); 331c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 332c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Start; 333c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 334c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 335c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!AddRecs.empty()) { 336c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Add the addrecs onto the end of the list. 337403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 338c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Resort the operand list, moving any constants to the front. 339c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 340c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 341c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 342c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 3434c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// expandAddToGEP - Expand an addition expression with a pointer type into 3444c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps 3454c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// BasicAliasAnalysis and other passes analyze the result. See the rules 3464c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for getelementptr vs. inttoptr in 3474c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// http://llvm.org/docs/LangRef.html#pointeraliasing 3484c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for details. 34913c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// 3503abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman/// Design note: The correctness of using getelementptr here depends on 3514c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as 3524c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// they may introduce pointer arithmetic which may not be safely converted 3534c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// into getelementptr. 354453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 355453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Design note: It might seem desirable for this function to be more 356453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-aware. If some of the indices are loop-invariant while others 357453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// aren't, it might seem desirable to emit multiple GEPs, keeping the 358453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of the overall computation outside the loop. 359453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// However, there are a few reasons this is not done here. Hoisting simple 360453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// arithmetic is a low-level optimization that often isn't very 361453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// important until late in the optimization process. In fact, passes 362453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// like InstructionCombining will combine GEPs, even if it means 363453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// pushing loop-invariant computation down into loops, so even if the 364453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEPs were split here, the work would quickly be undone. The 365453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// LoopStrengthReduction pass, which is usually run quite late (and 366453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// after the last InstructionCombining pass), takes care of hoisting 367453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of expressions, after considering what 368453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// can be folded using target addressing modes. 369453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 3700bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin, 3710bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *const *op_end, 372db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner PointerType *PTy, 373db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 3745be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *V) { 375db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ElTy = PTy->getElementType(); 3765be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman SmallVector<Value *, 4> GepIndices; 3770bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> Ops(op_begin, op_end); 3785be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman bool AnyNonZeroIndices = false; 3795be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 380c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Split AddRecs up into parts as either of the parts may be usable 381c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // without the other. 382c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SplitAddRecs(Ops, Ty, SE); 383c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 384eb35699e642f2c021f04154bdb4bd90a1afb3baaBob Wilson // Descend down the pointer's type and attempt to convert the other 3855be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // operands into GEP indices, at each level. The first index in a GEP 3865be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // indexes into the array implied by the pointer operand; the rest of 3875be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the indices index into the element or field type selected by the 3885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // preceding index. 3895be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (;;) { 390c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the scale size is not 0, attempt to factor out a scale for 391c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // array indexing. 3920bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> ScaledOps; 393150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (ElTy->isSized()) { 3944f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const SCEV *ElSize = SE.getSizeOfExpr(ElTy); 395150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ElSize->isZero()) { 396150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SmallVector<const SCEV *, 8> NewOps; 397150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 398150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman const SCEV *Op = Ops[i]; 399deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(Ty, 0); 400150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (FactorOutConstant(Op, Remainder, ElSize, SE, SE.TD)) { 401150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // Op now has ElSize factored out. 402150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman ScaledOps.push_back(Op); 403150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!Remainder->isZero()) 404150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Remainder); 405150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman AnyNonZeroIndices = true; 406150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } else { 407150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // The operand was not divisible, so add it to the list of operands 408150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // we'll scan next iteration. 409150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Ops[i]); 410150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 411150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 412150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // If we made any changes, update Ops. 413150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ScaledOps.empty()) { 414150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman Ops = NewOps; 415150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 4165be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 417c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4185be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 419c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 420c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Record the scaled array index for this level of the type. If 421c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // we didn't find any operands that could be factored, tentatively 422c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // assume that element zero was selected (since the zero offset 423c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // would obviously be folded away). 4245be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *Scaled = ScaledOps.empty() ? 425a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant::getNullValue(Ty) : 4265be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman expandCodeFor(SE.getAddExpr(ScaledOps), Ty); 4275be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman GepIndices.push_back(Scaled); 4285be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4295be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Collect struct field index operands. 430db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner while (StructType *STy = dyn_cast<StructType>(ElTy)) { 431c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman bool FoundFieldNo = false; 432c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // An empty struct has no fields. 433c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (STy->getNumElements() == 0) break; 434c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (SE.TD) { 435c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, field offsets are known. See if a constant offset 436c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // falls within any of the struct fields. 437c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Ops.empty()) break; 4385be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[0])) 4395be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (SE.getTypeSizeInBits(C->getType()) <= 64) { 4405be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const StructLayout &SL = *SE.TD->getStructLayout(STy); 4415be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman uint64_t FullOffset = C->getValue()->getZExtValue(); 4425be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (FullOffset < SL.getSizeInBytes()) { 4435be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(FullOffset); 4441d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson GepIndices.push_back( 4451d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson ConstantInt::get(Type::getInt32Ty(Ty->getContext()), ElIdx)); 4465be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = STy->getTypeAtIndex(ElIdx); 4475be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops[0] = 4486de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman SE.getConstant(Ty, FullOffset - SL.getElementOffset(ElIdx)); 4495be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman AnyNonZeroIndices = true; 450c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 4515be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4525be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 453c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 4540f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman // Without TargetData, just check for an offsetof expression of the 455c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // appropriate struct type. 456c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 4570f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Ops[i])) { 458db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *CTy; 4590f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman Constant *FieldNo; 4604f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (U->isOffsetOf(CTy, FieldNo) && CTy == STy) { 4610f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman GepIndices.push_back(FieldNo); 4620f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman ElTy = 4630f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman STy->getTypeAtIndex(cast<ConstantInt>(FieldNo)->getZExtValue()); 464c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = SE.getConstant(Ty, 0); 465c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AnyNonZeroIndices = true; 466c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 467c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 468c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4690f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman } 4705be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 471c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If no struct field offsets were found, tentatively assume that 472c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // field zero was selected (since the zero offset would obviously 473c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // be folded away). 474c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FoundFieldNo) { 475c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ElTy = STy->getTypeAtIndex(0u); 476c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman GepIndices.push_back( 477c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Constant::getNullValue(Type::getInt32Ty(Ty->getContext()))); 478c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 479c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4805be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 481db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (ArrayType *ATy = dyn_cast<ArrayType>(ElTy)) 4825be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = ATy->getElementType(); 483c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman else 484c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 4855be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4865be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4873f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If none of the operands were convertible to proper GEP indices, cast 4885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the base to i8* and do an ugly getelementptr with that. It's still 4895be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // better than ptrtoint+arithmetic+inttoptr at least. 4905be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (!AnyNonZeroIndices) { 491c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Cast the base to i8*. 4925be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, 493ac53a0b272452013124bfc70480aea5e41b60f40Duncan Sands Type::getInt8PtrTy(Ty->getContext(), PTy->getAddressSpace())); 494c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 495c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Expand the operands for a plain byte offset. 49692fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *Idx = expandCodeFor(SE.getAddExpr(Ops), Ty); 4975be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4985be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Fold a GEP with constant operands. 4995be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(V)) 5005be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(Idx)) 501dab3d29605a5c83db41b28176273ef55961120c1Jay Foad return ConstantExpr::getGetElementPtr(CLHS, CRHS); 5025be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 5035be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Do a quick scan to see if we have this GEP nearby. If so, reuse it. 5045be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ScanLimit = 6; 505267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 506267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 507267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 508267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 5095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman --IP; 5105be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (; ScanLimit; --IP, --ScanLimit) { 5118d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 5128d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 5138d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 5148d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 5155be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == Instruction::GetElementPtr && 5165be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(0) == V && IP->getOperand(1) == Idx) 5175be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 5185be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP == BlockBegin) break; 5195be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5205be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5215be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 522087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 523087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 524087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 525087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 526087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 527087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 528087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V) || !L->isLoopInvariant(Idx)) break; 529087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 530087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 531087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 532087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 533087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 534087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 535087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 536c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Emit a GEP. 537c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *GEP = Builder.CreateGEP(V, Idx, "uglygep"); 538a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 539087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 540087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 541087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 542087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 543087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5445be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return GEP; 5455be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5465be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 547087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 548087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 549087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 550087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 551087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 552087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 553087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V)) break; 554087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 555087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool AnyIndexNotLoopInvariant = false; 556087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<Value *>::const_iterator I = GepIndices.begin(), 557087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E = GepIndices.end(); I != E; ++I) 558087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(*I)) { 559087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman AnyIndexNotLoopInvariant = true; 560087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 561087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 562087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (AnyIndexNotLoopInvariant) 563087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 564087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 565087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 566087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 567087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 568087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 569087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 570087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 571087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 572d6aa02de1076c801ac41295156a2379637976918Dan Gohman // Insert a pretty getelementptr. Note that this GEP is not marked inbounds, 573d6aa02de1076c801ac41295156a2379637976918Dan Gohman // because ScalarEvolution may have changed the address arithmetic to 574d6aa02de1076c801ac41295156a2379637976918Dan Gohman // compute a value which is beyond the end of the allocated object. 575a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Casted = V; 576a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (V->getType() != PTy) 577a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Casted = InsertNoopCastOfTo(Casted, PTy); 578a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *GEP = Builder.CreateGEP(Casted, 5790a2a60ace9b79164b71794ce7ff981171c61e442Jay Foad GepIndices, 580267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "scevgep"); 5815be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops.push_back(SE.getUnknown(GEP)); 582a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 583087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 584087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 585087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 586087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 587087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return expand(SE.getAddExpr(Ops)); 5895be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman} 5905be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 591a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// isNonConstantNegative - Return true if the specified scev is negated, but 592a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// not a constant. 593a10756ee657a4d43a48cca5c166919093930ed6bDan Gohmanstatic bool isNonConstantNegative(const SCEV *F) { 594a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(F); 595a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!Mul) return false; 596a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 597a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If there is a constant factor, it will be first. 598a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVConstant *SC = dyn_cast<SCEVConstant>(Mul->getOperand(0)); 599a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!SC) return false; 600a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 601a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Return true if the value is negative, this matches things like (-42 * V). 602a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return SC->getValue()->getValue().isNegative(); 603a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 604a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 605087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// PickMostRelevantLoop - Given two loops pick the one that's most relevant for 606087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// SCEV expansion. If they are nested, this is the most nested. If they are 607087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// neighboring, pick the later. 608087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanstatic const Loop *PickMostRelevantLoop(const Loop *A, const Loop *B, 609087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT) { 610087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!A) return B; 611087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!B) return A; 612087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (A->contains(B)) return B; 613087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (B->contains(A)) return A; 614087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(A->getHeader(), B->getHeader())) return B; 615087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(B->getHeader(), A->getHeader())) return A; 616087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return A; // Arbitrarily break the tie. 617087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 618087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 6199c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman/// getRelevantLoop - Get the most relevant loop associated with the given 620087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// expression, according to PickMostRelevantLoop. 6219c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohmanconst Loop *SCEVExpander::getRelevantLoop(const SCEV *S) { 6229c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // Test whether we've already computed the most relevant loop for this SCEV. 6239c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman std::pair<DenseMap<const SCEV *, const Loop *>::iterator, bool> Pair = 6249c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman RelevantLoops.insert(std::make_pair(S, static_cast<const Loop *>(0))); 6259c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (!Pair.second) 6269c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return Pair.first->second; 6279c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman 628087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<SCEVConstant>(S)) 6299c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // A constant has no relevant loops. 630087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 631087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) { 632087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const Instruction *I = dyn_cast<Instruction>(U->getValue())) 6339c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return Pair.first->second = SE.LI->getLoopFor(I->getParent()); 6349c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // A non-instruction has no relevant loops. 635087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 636087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 637087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVNAryExpr *N = dyn_cast<SCEVNAryExpr>(S)) { 638087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *L = 0; 639087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) 640087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman L = AR->getLoop(); 641087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SCEVNAryExpr::op_iterator I = N->op_begin(), E = N->op_end(); 642087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I != E; ++I) 6439c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman L = PickMostRelevantLoop(L, getRelevantLoop(*I), *SE.DT); 6449c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[N] = L; 6459c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman } 6469c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(S)) { 6479c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman const Loop *Result = getRelevantLoop(C->getOperand()); 6489c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[C] = Result; 6499c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman } 6509c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (const SCEVUDivExpr *D = dyn_cast<SCEVUDivExpr>(S)) { 6519c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman const Loop *Result = 6529c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman PickMostRelevantLoop(getRelevantLoop(D->getLHS()), 6539c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman getRelevantLoop(D->getRHS()), 6549c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman *SE.DT); 6559c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[D] = Result; 656087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 657087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman llvm_unreachable("Unexpected SCEV type!"); 6589c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return 0; 659087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 660c4f7ec85ecb760fff2b702c6deb06506b968ba4fDan Gohman 661b35798347ea87b8b6d36155b211016a7769f01abDan Gohmannamespace { 662b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 663087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// LoopCompare - Compare loops by PickMostRelevantLoop. 664087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanclass LoopCompare { 665087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT; 666087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanpublic: 667087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman explicit LoopCompare(DominatorTree &dt) : DT(dt) {} 668087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 669087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool operator()(std::pair<const Loop *, const SCEV *> LHS, 670087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::pair<const Loop *, const SCEV *> RHS) const { 671bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // Keep pointer operands sorted at the end. 672bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (LHS.second->getType()->isPointerTy() != 673bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman RHS.second->getType()->isPointerTy()) 674bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman return LHS.second->getType()->isPointerTy(); 675bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman 676087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Compare loops with PickMostRelevantLoop. 677087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (LHS.first != RHS.first) 678087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return PickMostRelevantLoop(LHS.first, RHS.first, DT) != LHS.first; 679087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 680087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // If one operand is a non-constant negative and the other is not, 681087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // put the non-constant negative on the right so that a sub can 682087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // be used instead of a negate and add. 683087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isNonConstantNegative(LHS.second)) { 684087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!isNonConstantNegative(RHS.second)) 685087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 686087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (isNonConstantNegative(RHS.second)) 687087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return true; 688087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 689087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Otherwise they are equivalent according to this comparison. 690087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 691c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 692087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman}; 6935be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 694b35798347ea87b8b6d36155b211016a7769f01abDan Gohman} 695b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 696087bd1e3a12893873761736bf0f905a350e9e708Dan GohmanValue *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { 697db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 698e24fa64d52330626553298f56ba5aa702624c282Dan Gohman 699087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the add operands in a loop, along with their associated loops. 700087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal, and 701087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // so that pointer operands are inserted first, which the code below relies on 702087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // to form more involved GEPs. 703087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 704087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVAddExpr::op_iterator> I(S->op_end()), 705087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 7069c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I)); 707087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 708087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants and 709087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // pointer operands precede non-pointer operands. 710087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 711087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 712087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to add all the operands. Hoist as much as possible 713087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops, and form meaningful getelementptrs where possible. 714087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Sum = 0; 715087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 716087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 717087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *CurLoop = I->first; 718087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 719087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Sum) { 720087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 721087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expand(Op); 722087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 723db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner } else if (PointerType *PTy = dyn_cast<PointerType>(Sum->getType())) { 724087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum expression is a pointer. Try to form a getelementptr 725087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // at this level with that as the base. 726087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 727bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman for (; I != E && I->first == CurLoop; ++I) { 728bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // If the operand is SCEVUnknown and not instructions, peek through 729bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // it, to enable more of it to be folded into the GEP. 730bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman const SCEV *X = I->second; 731bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(X)) 732bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (!isa<Instruction>(U->getValue())) 733bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman X = SE.getSCEV(U->getValue()); 734bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman NewOps.push_back(X); 735bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman } 736087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum); 737db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner } else if (PointerType *PTy = dyn_cast<PointerType>(Op->getType())) { 738087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum is an integer, and there's a pointer at this level. 739f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // Try to form a getelementptr. If the running sum is instructions, 740f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // use a SCEVUnknown to avoid re-analyzing them. 741087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 742f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman NewOps.push_back(isa<Instruction>(Sum) ? SE.getUnknown(Sum) : 743f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman SE.getSCEV(Sum)); 744087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (++I; I != E && I->first == CurLoop; ++I) 745087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman NewOps.push_back(I->second); 746087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, expand(Op)); 747087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (isNonConstantNegative(Op)) { 748087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a negate and add, just do a subtract. 749a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(SE.getNegativeSCEV(Op), Ty); 750087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 751087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Sub, Sum, W); 752087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 753a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 754087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple add. 755a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(Op, Ty); 756087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 757087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 758087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Sum)) std::swap(Sum, W); 759087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Add, Sum, W); 760087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 761a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 7622d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 763087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 764087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Sum; 765e24fa64d52330626553298f56ba5aa702624c282Dan Gohman} 7665be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 767890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) { 768db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 769087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 770087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the mul operands in a loop, along with their associated loops. 771087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal. 772087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 773087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVMulExpr::op_iterator> I(S->op_end()), 774087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 7759c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I)); 776087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 777087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants. 778087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 779087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 780087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to mul all the operands. Hoist as much as possible 781087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops. 782087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Prod = 0; 783087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 784087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 785087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 786087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Prod) { 787087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 788087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = expand(Op); 789087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 790087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (Op->isAllOnesValue()) { 791087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a multiply by negative one, just do a negate. 792087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 793087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Sub, Constant::getNullValue(Ty), Prod); 794087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 795087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else { 796087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple mul. 797087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *W = expandCodeFor(Op, Ty); 798087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 799087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 800087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Prod)) std::swap(Prod, W); 801087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Mul, Prod, W); 802087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 803087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 8042d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 8052d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 806087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Prod; 80736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 80836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 809890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) { 810db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 8112d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 81292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *LHS = expandCodeFor(S->getLHS(), Ty); 813890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getRHS())) { 8146177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky const APInt &RHS = SC->getValue()->getValue(); 8156177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky if (RHS.isPowerOf2()) 8166177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky return InsertBinop(Instruction::LShr, LHS, 817eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson ConstantInt::get(Ty, RHS.logBase2())); 8186177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky } 8196177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 82092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getRHS(), Ty); 821267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman return InsertBinop(Instruction::UDiv, LHS, RHS); 8226177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky} 8236177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 824453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Move parts of Base into Rest to leave Base with the minimal 825453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// expression that provides a pointer operand suitable for a 826453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEP expansion. 8270bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic void ExposePointerBase(const SCEV *&Base, const SCEV *&Rest, 828453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ScalarEvolution &SE) { 829453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Base)) { 830453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getStart(); 831453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(Rest, 832deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getAddRecExpr(SE.getConstant(A->getType(), 0), 833453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getStepRecurrence(SE), 8343228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick A->getLoop(), 8353228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: A->getNoWrapFlags(FlagNW) 8363228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 837453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 838453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(Base)) { 839453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getOperand(A->getNumOperands()-1); 8400bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> NewAddOps(A->op_begin(), A->op_end()); 841453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman NewAddOps.back() = Rest; 842453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(NewAddOps); 843453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ExposePointerBase(Base, Rest, SE); 844453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 845453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 846453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 847c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// Determine if this is a well-behaved chain of instructions leading back to 848c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// the PHI. If so, it may be reused by expanded expressions. 849c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trickbool SCEVExpander::isNormalAddRecExprPHI(PHINode *PN, Instruction *IncV, 850c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick const Loop *L) { 851c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getNumOperands() == 0 || isa<PHINode>(IncV) || 852c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick (isa<CastInst>(IncV) && !isa<BitCastInst>(IncV))) 853c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 854c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // If any of the operands don't dominate the insert position, bail. 855c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Addrec operands are always loop-invariant, so this can only happen 856c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // if there are instructions which haven't been hoisted. 857c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (L == IVIncInsertLoop) { 858c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (User::op_iterator OI = IncV->op_begin()+1, 859c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick OE = IncV->op_end(); OI != OE; ++OI) 860c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (Instruction *OInst = dyn_cast<Instruction>(OI)) 861c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!SE.DT->dominates(OInst, IVIncInsertPos)) 862c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 863c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 864c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Advance to the next instruction. 865c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 866c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!IncV) 867c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 868c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 869c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->mayHaveSideEffects()) 870c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 871c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 872c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV != PN) 873c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return true; 874c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 875c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return isNormalAddRecExprPHI(PN, IncV, L); 876c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick} 877c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 878c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// Determine if this cyclic phi is in a form that would have been generated by 879c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// LSR. We don't care if the phi was actually expanded in this pass, as long 880c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// as it is in a low-cost form, for example, no implied multiplication. This 881c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// should match any patterns generated by getAddRecExprPHILiterally and 882c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// expandAddtoGEP. 883c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trickbool SCEVExpander::isExpandedAddRecExprPHI(PHINode *PN, Instruction *IncV, 884c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick const Loop *L, Type *ExpandTy) { 885c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick switch (IncV->getOpcode()) { 886c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Check for a simple Add/Sub or GEP of a loop invariant step. 887c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::Add: 888c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::Sub: 889c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return IncV->getOperand(0) == PN 890c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick && L->isLoopInvariant(IncV->getOperand(1)); 891c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::BitCast: 892c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = dyn_cast<GetElementPtrInst>(IncV->getOperand(0)); 893c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!IncV) 894c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 895c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // fall-thru to GEP handling 896c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::GetElementPtr: { 897c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // This must be a pointer addition of constants (pretty) or some number of 898c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // address-size elements (ugly). 899c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (Instruction::op_iterator I = IncV->op_begin()+1, E = IncV->op_end(); 900c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick I != E; ++I) { 901c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (isa<Constant>(*I)) 902c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 903c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // ugly geps have 2 operands. 904c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // i1* is used by the expander to represent an address-size element. 905c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getNumOperands() != 2) 906c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 907c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick unsigned AS = cast<PointerType>(ExpandTy)->getAddressSpace(); 908c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getType() != Type::getInt1PtrTy(SE.getContext(), AS) 909c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick && IncV->getType() != Type::getInt8PtrTy(SE.getContext(), AS)) 910c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 91194794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick // Ensure the operands dominate the insertion point. I don't know of a 91294794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick // case when this would not be true, so this is somewhat untested. 91394794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick if (L == IVIncInsertLoop) { 91494794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick for (User::op_iterator OI = IncV->op_begin()+1, 91594794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick OE = IncV->op_end(); OI != OE; ++OI) 91694794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick if (Instruction *OInst = dyn_cast<Instruction>(OI)) 91794794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick if (!SE.DT->dominates(OInst, IVIncInsertPos)) 91894794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick return false; 91994794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick } 920c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick break; 921c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 922c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 923c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV && IncV->getOpcode() == Instruction::BitCast) 924c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 925c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return IncV == PN; 926c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 927c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick default: 928c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 929c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 930c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick} 931c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 932a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// getAddRecExprPHILiterally - Helper for expandAddRecExprLiterally. Expand 933a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// the base addrec, which is the addrec without any non-loop-dominating 934a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// values, and return the PHI. 935a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanPHINode * 936a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanSCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized, 937a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L, 938db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ExpandTy, 939db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntTy) { 94093a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer assert((!IVIncInsertLoop||IVIncInsertPos) && "Uninitialized insert position"); 941d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 942a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Reuse a previously-inserted PHI, if present. 943c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick BasicBlock *LatchBlock = L->getLoopLatch(); 944c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (LatchBlock) { 945c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (BasicBlock::iterator I = L->getHeader()->begin(); 946c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick PHINode *PN = dyn_cast<PHINode>(I); ++I) { 947c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!SE.isSCEVable(PN->getType()) || 948c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick (SE.getEffectiveSCEVType(PN->getType()) != 949c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick SE.getEffectiveSCEVType(Normalized->getType())) || 950c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick SE.getSCEV(PN) != Normalized) 951c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 952c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 953c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick Instruction *IncV = 954c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)); 955c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 956c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (LSRMode) { 957c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!isExpandedAddRecExprPHI(PN, IncV, L, ExpandTy)) 958c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 959c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 960c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick else { 961c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!isNormalAddRecExprPHI(PN, IncV, L)) 962c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 963c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 964c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Ok, the add recurrence looks usable. 965c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Remember this PHI, even in post-inc mode. 966c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick InsertedValues.insert(PN); 967c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Remember the increment. 968c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick rememberInstruction(IncV); 969c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (L == IVIncInsertLoop) 97022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman do { 971c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (SE.DT->dominates(IncV, IVIncInsertPos)) 9729feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman break; 973c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Make sure the increment is where we want it. But don't move it 974c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // down past a potential existing post-inc user. 975c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV->moveBefore(IVIncInsertPos); 976c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IVIncInsertPos = IncV; 977c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = cast<Instruction>(IncV->getOperand(0)); 97822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } while (IncV != PN); 979c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return PN; 980c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 981c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 982a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 983a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Save the original insertion point so we can restore it when we're done. 984a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 985a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 986a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 987a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the start value. 988a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StartV = expandCodeFor(Normalized->getStart(), ExpandTy, 989a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman L->getHeader()->begin()); 990a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 991d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick // StartV must be hoisted into L's preheader to dominate the new phi. 99293a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer assert(!isa<Instruction>(StartV) || 99393a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer SE.DT->properlyDominates(cast<Instruction>(StartV)->getParent(), 99493a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer L->getHeader())); 995d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 996a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the step value. Insert instructions right before the 997a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // terminator corresponding to the back-edge. Do this before creating the PHI 998a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // so that PHI reuse code doesn't see an incomplete PHI. If the stride is 999a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // negative, insert a sub instead of an add for the increment (unless it's a 1000a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // constant, because subtracts of constants are canonicalized to adds). 1001a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 10021df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands bool isPointer = ExpandTy->isPointerTy(); 1003a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman bool isNegative = !isPointer && isNonConstantNegative(Step); 1004a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (isNegative) 1005a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Step = SE.getNegativeSCEV(Step); 1006a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StepV = expandCodeFor(Step, IntTy, L->getHeader()->begin()); 1007a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1008a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the PHI. 1009d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad BasicBlock *Header = L->getHeader(); 1010d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad Builder.SetInsertPoint(Header, Header->begin()); 1011d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad pred_iterator HPB = pred_begin(Header), HPE = pred_end(Header); 10125e7645be4c9dd2193add44d30b5fef8036d7a3ceAndrew Trick PHINode *PN = Builder.CreatePHI(ExpandTy, std::distance(HPB, HPE), 1013dc8e546048db2f7ff5656742b2b26975098a11a0Andrew Trick Twine(IVName) + ".iv"); 1014a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(PN); 1015a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1016a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the step instructions and populate the PHI. 1017d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad for (pred_iterator HPI = HPB; HPI != HPE; ++HPI) { 1018a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *Pred = *HPI; 1019a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1020a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Add a start value. 1021a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!L->contains(Pred)) { 1022a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(StartV, Pred); 1023a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman continue; 1024a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1025a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1026a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create a step value and add it to the PHI. If IVIncInsertLoop is 1027a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // non-null and equal to the addrec's loop, insert the instructions 1028a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // at IVIncInsertPos. 1029a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Instruction *InsertPos = L == IVIncInsertLoop ? 1030a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IVIncInsertPos : Pred->getTerminator(); 1031c5ecbdc1896f1cc089372feef3191ace2f840898Devang Patel Builder.SetInsertPoint(InsertPos); 1032a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *IncV; 1033a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If the PHI is a pointer, use a GEP, otherwise use an add or sub. 1034a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (isPointer) { 1035db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner PointerType *GEPPtrTy = cast<PointerType>(ExpandTy); 1036a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If the step isn't constant, don't use an implicitly scaled GEP, because 1037a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // that would require a multiply inside the loop. 1038a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!isa<ConstantInt>(StepV)) 1039a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman GEPPtrTy = PointerType::get(Type::getInt1Ty(SE.getContext()), 1040a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman GEPPtrTy->getAddressSpace()); 1041a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const StepArray[1] = { SE.getSCEV(StepV) }; 1042a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = expandAddToGEP(StepArray, StepArray+1, GEPPtrTy, IntTy, PN); 1043a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (IncV->getType() != PN->getType()) { 1044a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer IncV = Builder.CreateBitCast(IncV, PN->getType()); 1045a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(IncV); 1046a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1047a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 1048a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = isNegative ? 1049dc8e546048db2f7ff5656742b2b26975098a11a0Andrew Trick Builder.CreateSub(PN, StepV, Twine(IVName) + ".iv.next") : 1050dc8e546048db2f7ff5656742b2b26975098a11a0Andrew Trick Builder.CreateAdd(PN, StepV, Twine(IVName) + ".iv.next"); 1051a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(IncV); 1052a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1053a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(IncV, Pred); 1054a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1055a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1056a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Restore the original insert point. 1057a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (SaveInsertBB) 1058455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1059a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1060a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Remember this PHI, even in post-inc mode. 1061a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman InsertedValues.insert(PN); 1062a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1063a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return PN; 1064a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1065a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1066a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanValue *SCEVExpander::expandAddRecExprLiterally(const SCEVAddRecExpr *S) { 1067db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *STy = S->getType(); 1068db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntTy = SE.getEffectiveSCEVType(STy); 1069a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L = S->getLoop(); 1070a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1071a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Determine a normalized form of this expression, which is the expression 1072a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // before any post-inc adjustment is made. 1073a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVAddRecExpr *Normalized = S; 1074448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (PostIncLoops.count(L)) { 1075448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman PostIncLoopSet Loops; 1076448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops.insert(L); 1077448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Normalized = 1078448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman cast<SCEVAddRecExpr>(TransformForPostIncUse(Normalize, S, 0, 0, 1079448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops, SE, *SE.DT)); 1080a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1081a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1082a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec start. 1083a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Start = Normalized->getStart(); 1084a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopOffset = 0; 1085dc0e8fb9f9512622f55f73e1a434caa5c0915694Dan Gohman if (!SE.properlyDominates(Start, L->getHeader())) { 1086a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopOffset = Start; 1087deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Start = SE.getConstant(Normalized->getType(), 0); 10883228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized = cast<SCEVAddRecExpr>( 10893228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SE.getAddRecExpr(Start, Normalized->getStepRecurrence(SE), 10903228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized->getLoop(), 10913228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: Normalized->getNoWrapFlags(FlagNW) 10923228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1093a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1094a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1095a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec step. 1096a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 1097a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopScale = 0; 1098dc0e8fb9f9512622f55f73e1a434caa5c0915694Dan Gohman if (!SE.dominates(Step, L->getHeader())) { 1099a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopScale = Step; 1100deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Step = SE.getConstant(Normalized->getType(), 1); 1101a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized = 1102a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start, Step, 11033228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized->getLoop(), 11043228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: Normalized 11053228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // ->getNoWrapFlags(FlagNW) 11063228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1107a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1108a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1109a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand the core addrec. If we need post-loop scaling, force it to 1110a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // expand to an integer type to avoid the need for additional casting. 1111db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ExpandTy = PostLoopScale ? IntTy : STy; 1112a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = getAddRecExprPHILiterally(Normalized, L, ExpandTy, IntTy); 1113a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 11143f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // Accommodate post-inc mode, if necessary. 1115a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Result; 1116448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (!PostIncLoops.count(L)) 1117a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN; 1118a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman else { 1119a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // In PostInc mode, use the post-incremented value. 1120a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *LatchBlock = L->getLoopLatch(); 1121a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman assert(LatchBlock && "PostInc mode requires a unique loop latch!"); 1122a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN->getIncomingValueForBlock(LatchBlock); 112348ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick 112448ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // For an expansion to use the postinc form, the client must call 112548ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // expandCodeFor with an InsertPoint that is either outside the PostIncLoop 112648ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // or dominated by IVIncInsertPos. 112748ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick assert((!isa<Instruction>(Result) || 112848ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick SE.DT->dominates(cast<Instruction>(Result), 112948ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick Builder.GetInsertPoint())) && 113048ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick "postinc expansion does not dominate use"); 1131a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1132a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1133a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating scale. 1134a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopScale) { 11350a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1136a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateMul(Result, 1137a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopScale, IntTy)); 1138a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1139a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1140a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1141a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating offset. 1142a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopOffset) { 1143db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (PointerType *PTy = dyn_cast<PointerType>(ExpandTy)) { 1144a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const OffsetArray[1] = { PostLoopOffset }; 1145a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = expandAddToGEP(OffsetArray, OffsetArray+1, PTy, IntTy, Result); 1146a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 11470a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1148a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateAdd(Result, 1149a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopOffset, IntTy)); 1150a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1151a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1152a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1153a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1154a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return Result; 1155a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1156a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1157890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { 1158a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!CanonicalMode) return expandAddRecExprLiterally(S); 1159a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1160db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 116136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Loop *L = S->getLoop(); 116236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11634d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // First check for an existing canonical IV in a suitable type. 11644d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman PHINode *CanonicalIV = 0; 11654d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (PHINode *PN = L->getCanonicalInductionVariable()) 1166133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman if (SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty)) 11674d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV = PN; 11684d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 11694d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Rewrite an AddRec in terms of the canonical induction variable, if 11704d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // its type is more narrow. 11714d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (CanonicalIV && 11724d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(CanonicalIV->getType()) > 11734d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(Ty)) { 1174f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->getNumOperands()); 1175f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman for (unsigned i = 0, e = S->getNumOperands(); i != e; ++i) 1176f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman NewOps[i] = SE.getAnyExtendExpr(S->op_begin()[i], CanonicalIV->getType()); 11773228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Value *V = expand(SE.getAddRecExpr(NewOps, S->getLoop(), 11783228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: S->getNoWrapFlags(FlagNW) 11793228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1180267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1181267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 11824d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman BasicBlock::iterator NewInsertPt = 11837896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner llvm::next(BasicBlock::iterator(cast<Instruction>(V))); 1184a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling while (isa<PHINode>(NewInsertPt) || isa<DbgInfoIntrinsic>(NewInsertPt) || 1185a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(NewInsertPt)) 118608f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach ++NewInsertPt; 11874d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), 0, 11884d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewInsertPt); 1189455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 11904d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman return V; 11914d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman } 11924d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 119336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {X,+,F} --> X + {0,+,F} 1194cfeb6a450632f2a6cd05302633c8c2b8c90cfdfdDan Gohman if (!S->getStart()->isZero()) { 1195f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->op_begin(), S->op_end()); 1196deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman NewOps[0] = SE.getConstant(Ty, 0); 11973228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: can use S->getNoWrapFlags() 11983228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick const SCEV *Rest = SE.getAddRecExpr(NewOps, L, SCEV::FlagAnyWrap); 1199453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 1200453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the 1201453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // comments on expandAddToGEP for details. 1202c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Base = S->getStart(); 1203c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *RestArray[1] = { Rest }; 1204c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Dig into the expression to find the pointer base for a GEP. 1205c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ExposePointerBase(Base, RestArray[0], SE); 1206c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If we found a pointer, expand the AddRec with a GEP. 1207db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (PointerType *PTy = dyn_cast<PointerType>(Base->getType())) { 1208c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Make sure the Base isn't something exotic, such as a multiplied 1209c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // or divided pointer value. In those cases, the result type isn't 1210c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // actually a pointer type. 1211c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!isa<SCEVMulExpr>(Base) && !isa<SCEVUDivExpr>(Base)) { 1212c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *StartV = expand(Base); 1213c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman assert(StartV->getType() == PTy && "Pointer type mismatch for GEP!"); 1214c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return expandAddToGEP(RestArray, RestArray+1, PTy, Ty, StartV); 1215453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1216453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1217453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 121840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Just do a normal add. Pre-expand the operands to suppress folding. 121940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return expand(SE.getAddExpr(SE.getUnknown(expand(S->getStart())), 122040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getUnknown(expand(Rest)))); 122136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 122236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12236ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // If we don't yet have a canonical IV, create one. 12246ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (!CanonicalIV) { 122536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Create and insert the PHI node for the induction variable in the 122636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // specified loop. 122736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman BasicBlock *Header = L->getHeader(); 1228d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad pred_iterator HPB = pred_begin(Header), HPE = pred_end(Header); 12293ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad CanonicalIV = PHINode::Create(Ty, std::distance(HPB, HPE), "indvar", 12303ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad Header->begin()); 12316ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman rememberInstruction(CanonicalIV); 123236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1233eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Constant *One = ConstantInt::get(Ty, 1); 1234d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad for (pred_iterator HPI = HPB; HPI != HPE; ++HPI) { 12357656018c2268285907cfdc106071462a01a73878Gabor Greif BasicBlock *HP = *HPI; 12367656018c2268285907cfdc106071462a01a73878Gabor Greif if (L->contains(HP)) { 12373abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // Insert a unit add instruction right before the terminator 12383abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // corresponding to the back-edge. 12396ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman Instruction *Add = BinaryOperator::CreateAdd(CanonicalIV, One, 12406ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "indvar.next", 12416ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman HP->getTerminator()); 1242df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel Add->setDebugLoc(HP->getTerminator()->getDebugLoc()); 1243a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Add); 12446ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Add, HP); 124583d577490b1473213b6973236110c28e59127956Dan Gohman } else { 12466ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Constant::getNullValue(Ty), HP); 124783d577490b1473213b6973236110c28e59127956Dan Gohman } 12487656018c2268285907cfdc106071462a01a73878Gabor Greif } 124936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 125036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12516ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // {0,+,1} --> Insert a canonical induction variable into the loop! 12526ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (S->isAffine() && S->getOperand(1)->isOne()) { 12536ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) && 12546ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "IVs with types different from the canonical IV should " 12556ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "already have been handled!"); 12566ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman return CanonicalIV; 12576ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman } 12586ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman 12594d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // {0,+,F} --> {0,+,1} * F 126036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1261df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If this is a simple linear addrec, emit it now as a special case. 126240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (S->isAffine()) // {0,+,F} --> i*F 126340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return 126440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman expand(SE.getTruncateOrNoop( 12656ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman SE.getMulExpr(SE.getUnknown(CanonicalIV), 126640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getNoopOrAnyExtend(S->getOperand(1), 12676ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->getType())), 126840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Ty)); 126936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 127036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // If this is a chain of recurrences, turn it into a closed form, using the 127136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // folders, then expandCodeFor the closed form. This allows the folders to 127236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // simplify the expression without having to build a bunch of special code 127336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // into this folder. 12746ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *IH = SE.getUnknown(CanonicalIV); // Get I as a "symbolic" SCEV. 127536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12764d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Promote S up to the canonical IV type, if the cast is foldable. 12770bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *NewS = S; 12786ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *Ext = SE.getNoopOrAnyExtend(S, CanonicalIV->getType()); 12794d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (isa<SCEVAddRecExpr>(Ext)) 12804d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewS = Ext; 12814d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 12820bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE); 1283e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; 128436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12854d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Truncate the result down to the original type, if needed. 12860bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *T = SE.getTruncateOrNoop(V, Ty); 1287469f3cdc13851914f3a766cbd8f701cf8431cacaDan Gohman return expand(T); 128836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 128996fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 1290890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitTruncateExpr(const SCEVTruncateExpr *S) { 1291db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 129292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 129392fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1294a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateTrunc(V, Ty); 1295a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1296cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 129711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 129811f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1299890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitZeroExtendExpr(const SCEVZeroExtendExpr *S) { 1300db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 130192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 130292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1303a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateZExt(V, Ty); 1304a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1305cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 130611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 130711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1308890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) { 1309db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 131092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 131192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1312a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateSExt(V, Ty); 1313a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1314cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 131511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 131611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1317890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { 13180196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 1319db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = LHS->getType(); 13200196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 13210196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 13220196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 13230196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 13240196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 13250196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 13260196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 132792fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1328a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *ICmp = Builder.CreateICmpSGT(LHS, RHS); 1329a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1330267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "smax"); 1331a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1332cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 1333c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky } 13340196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 13350196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 13360196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 13370196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 1338c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky return LHS; 1339c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky} 1340c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky 1341890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { 13420196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 1343db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = LHS->getType(); 13440196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 13450196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 13460196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 13470196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 13480196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 13490196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 13500196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 135192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1352a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *ICmp = Builder.CreateICmpUGT(LHS, RHS); 1353a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1354267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "umax"); 1355a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1356cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 13573e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky } 13580196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 13590196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 13600196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 13610196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 13623e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky return LHS; 13633e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky} 13643e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky 1365db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::expandCodeFor(const SCEV *SH, Type *Ty, 13666c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Instruction *I) { 13676c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman BasicBlock::iterator IP = I; 13686c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(IP) || isa<DbgInfoIntrinsic>(IP)) 13696c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman ++IP; 13706c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Builder.SetInsertPoint(IP->getParent(), IP); 13716c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman return expandCodeFor(SH, Ty); 13726c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman} 13736c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman 1374db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::expandCodeFor(const SCEV *SH, Type *Ty) { 137511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman // Expand the code for this SCEV. 13762d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *V = expand(SH); 13775be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Ty) { 13785be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman assert(SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(SH->getType()) && 13795be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman "non-trivial casts should be done with the SCEVs directly!"); 13805be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, Ty); 13815be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 13825be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return V; 138311f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 138411f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1385890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::expand(const SCEV *S) { 138640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Compute an insertion point for this SCEV object. Hoist the instructions 138740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // as far out in the loop nest as possible. 1388267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *InsertPt = Builder.GetInsertPoint(); 1389267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman for (Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock()); ; 139040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman L = L->getParentLoop()) 139117ead4ff4baceb2c5503f233d0288d363ae44165Dan Gohman if (SE.isLoopInvariant(S, L)) { 139240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (!L) break; 1393e059ee832ca36d65a5fb87b0ac5bcdb0490b15cbDan Gohman if (BasicBlock *Preheader = L->getLoopPreheader()) 139440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = Preheader->getTerminator(); 139540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } else { 139640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // If the SCEV is computable at this level, insert it into the header 139740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // after the PHIs (and after any other instructions that we've inserted 139840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // there) so that it is guaranteed to dominate any user inside the loop. 13995b6f42f57e730c2d968c313a27fa505a3c3e5efaBill Wendling if (L && SE.hasComputableLoopEvolution(S, L) && !PostIncLoops.count(L)) 14005b6f42f57e730c2d968c313a27fa505a3c3e5efaBill Wendling InsertPt = L->getHeader()->getFirstInsertionPt(); 14016c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(InsertPt) || isa<DbgInfoIntrinsic>(InsertPt)) 14027896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner InsertPt = llvm::next(BasicBlock::iterator(InsertPt)); 140340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman break; 140440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } 140540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1406667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Check to see if we already expanded this here. 1407667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman std::map<std::pair<const SCEV *, Instruction *>, 1408667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman AssertingVH<Value> >::iterator I = 1409667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman InsertedExpressions.find(std::make_pair(S, InsertPt)); 1410267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (I != InsertedExpressions.end()) 1411667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman return I->second; 1412267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 1413267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1414267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1415267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(InsertPt->getParent(), InsertPt); 1416667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1417667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Expand the expression into instructions. 141896fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov Value *V = visit(S); 141940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1420667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Remember the expanded value for this SCEV at this location. 142148ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // 142248ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // This is independent of PostIncLoops. The mapped value simply materializes 142348ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // the expression at this insertion point. If the mapped value happened to be 142448ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // a postinc expansion, it could be reused by a non postinc user, but only if 142548ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // its insertion point was already at the head of the loop. 142648ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick InsertedExpressions[std::make_pair(S, InsertPt)] = V; 1427667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1428455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 142996fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return V; 143096fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov} 14311d09de3eca23267855e28297fcb40de3632ea47bDan Gohman 14321d826a76f591afea445489b9a5485c345e66bf87Dan Gohmanvoid SCEVExpander::rememberInstruction(Value *I) { 143325fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman if (!PostIncLoops.empty()) 143425fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman InsertedPostIncValues.insert(I); 143525fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman else 14361d826a76f591afea445489b9a5485c345e66bf87Dan Gohman InsertedValues.insert(I); 14371d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 14381d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // If we just claimed an existing instruction and that instruction had 14393228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // been the insert point, adjust the insert point forward so that 14401d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // subsequently inserted code will be dominated. 14411d826a76f591afea445489b9a5485c345e66bf87Dan Gohman if (Builder.GetInsertPoint() == I) { 14421d826a76f591afea445489b9a5485c345e66bf87Dan Gohman BasicBlock::iterator It = cast<Instruction>(I); 14436c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman do { ++It; } while (isInsertedInstruction(It) || 14446c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman isa<DbgInfoIntrinsic>(It)); 14451d826a76f591afea445489b9a5485c345e66bf87Dan Gohman Builder.SetInsertPoint(Builder.GetInsertBlock(), It); 14461d826a76f591afea445489b9a5485c345e66bf87Dan Gohman } 14471d826a76f591afea445489b9a5485c345e66bf87Dan Gohman} 14481d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 1449455985501381777db03534c925a35e261e356395Dan Gohmanvoid SCEVExpander::restoreInsertPoint(BasicBlock *BB, BasicBlock::iterator I) { 14503f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If we acquired more instructions since the old insert point was saved, 1451455985501381777db03534c925a35e261e356395Dan Gohman // advance past them. 14526c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(I) || isa<DbgInfoIntrinsic>(I)) ++I; 1453455985501381777db03534c925a35e261e356395Dan Gohman 1454455985501381777db03534c925a35e261e356395Dan Gohman Builder.SetInsertPoint(BB, I); 1455455985501381777db03534c925a35e261e356395Dan Gohman} 1456455985501381777db03534c925a35e261e356395Dan Gohman 14571d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// getOrInsertCanonicalInductionVariable - This method returns the 14581d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// canonical induction variable of the specified type for the specified 14591d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// loop (inserting one if there is none). A canonical induction variable 14601d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// starts at zero and steps by one on each iteration. 14617c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan GohmanPHINode * 14621d09de3eca23267855e28297fcb40de3632ea47bDan GohmanSCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L, 1463db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty) { 1464b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands assert(Ty->isIntegerTy() && "Can only insert integer induction variables!"); 1465133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1466133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Build a SCEV for {0,+,1}<L>. 14673228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // Conservatively use FlagAnyWrap for now. 1468deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *H = SE.getAddRecExpr(SE.getConstant(Ty, 0), 14693228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SE.getConstant(Ty, 1), L, SCEV::FlagAnyWrap); 1470133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1471133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Emit code for it. 1472267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1473267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 14747c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan Gohman PHINode *V = cast<PHINode>(expandCodeFor(H, 0, L->getHeader()->begin())); 1475267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (SaveInsertBB) 1476455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1477133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 147840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return V; 14791d09de3eca23267855e28297fcb40de3632ea47bDan Gohman} 1480204494149b6f846e8f173f525b129f5508076049Andrew Trick 1481204494149b6f846e8f173f525b129f5508076049Andrew Trick/// hoistStep - Attempt to hoist an IV increment above a potential use. 1482204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1483204494149b6f846e8f173f525b129f5508076049Andrew Trick/// To successfully hoist, two criteria must be met: 1484204494149b6f846e8f173f525b129f5508076049Andrew Trick/// - IncV operands dominate InsertPos and 1485204494149b6f846e8f173f525b129f5508076049Andrew Trick/// - InsertPos dominates IncV 1486204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1487204494149b6f846e8f173f525b129f5508076049Andrew Trick/// Meeting the second condition means that we don't need to check all of IncV's 1488204494149b6f846e8f173f525b129f5508076049Andrew Trick/// existing uses (it's moving up in the domtree). 1489204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1490204494149b6f846e8f173f525b129f5508076049Andrew Trick/// This does not yet recursively hoist the operands, although that would 1491204494149b6f846e8f173f525b129f5508076049Andrew Trick/// not be difficult. 1492204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1493204494149b6f846e8f173f525b129f5508076049Andrew Trick/// This does not require a SCEVExpander instance and could be replaced by a 1494204494149b6f846e8f173f525b129f5508076049Andrew Trick/// general code-insertion helper. 1495204494149b6f846e8f173f525b129f5508076049Andrew Trickbool SCEVExpander::hoistStep(Instruction *IncV, Instruction *InsertPos, 1496204494149b6f846e8f173f525b129f5508076049Andrew Trick const DominatorTree *DT) { 1497204494149b6f846e8f173f525b129f5508076049Andrew Trick if (DT->dominates(IncV, InsertPos)) 1498204494149b6f846e8f173f525b129f5508076049Andrew Trick return true; 1499204494149b6f846e8f173f525b129f5508076049Andrew Trick 1500204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!DT->dominates(InsertPos->getParent(), IncV->getParent())) 1501204494149b6f846e8f173f525b129f5508076049Andrew Trick return false; 1502204494149b6f846e8f173f525b129f5508076049Andrew Trick 1503204494149b6f846e8f173f525b129f5508076049Andrew Trick if (IncV->mayHaveSideEffects()) 1504204494149b6f846e8f173f525b129f5508076049Andrew Trick return false; 1505204494149b6f846e8f173f525b129f5508076049Andrew Trick 1506204494149b6f846e8f173f525b129f5508076049Andrew Trick // Attempt to hoist IncV 1507204494149b6f846e8f173f525b129f5508076049Andrew Trick for (User::op_iterator OI = IncV->op_begin(), OE = IncV->op_end(); 1508204494149b6f846e8f173f525b129f5508076049Andrew Trick OI != OE; ++OI) { 1509204494149b6f846e8f173f525b129f5508076049Andrew Trick Instruction *OInst = dyn_cast<Instruction>(OI); 1510204494149b6f846e8f173f525b129f5508076049Andrew Trick if (OInst && !DT->dominates(OInst, InsertPos)) 1511204494149b6f846e8f173f525b129f5508076049Andrew Trick return false; 1512204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1513204494149b6f846e8f173f525b129f5508076049Andrew Trick IncV->moveBefore(InsertPos); 1514204494149b6f846e8f173f525b129f5508076049Andrew Trick return true; 1515204494149b6f846e8f173f525b129f5508076049Andrew Trick} 1516204494149b6f846e8f173f525b129f5508076049Andrew Trick 1517204494149b6f846e8f173f525b129f5508076049Andrew Trick/// replaceCongruentIVs - Check for congruent phis in this loop header and 1518204494149b6f846e8f173f525b129f5508076049Andrew Trick/// replace them with their most canonical representative. Return the number of 1519204494149b6f846e8f173f525b129f5508076049Andrew Trick/// phis eliminated. 1520204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1521204494149b6f846e8f173f525b129f5508076049Andrew Trick/// This does not depend on any SCEVExpander state but should be used in 1522204494149b6f846e8f173f525b129f5508076049Andrew Trick/// the same context that SCEVExpander is used. 1523204494149b6f846e8f173f525b129f5508076049Andrew Trickunsigned SCEVExpander::replaceCongruentIVs(Loop *L, const DominatorTree *DT, 1524204494149b6f846e8f173f525b129f5508076049Andrew Trick SmallVectorImpl<WeakVH> &DeadInsts) { 1525204494149b6f846e8f173f525b129f5508076049Andrew Trick unsigned NumElim = 0; 1526204494149b6f846e8f173f525b129f5508076049Andrew Trick DenseMap<const SCEV *, PHINode *> ExprToIVMap; 1527204494149b6f846e8f173f525b129f5508076049Andrew Trick for (BasicBlock::iterator I = L->getHeader()->begin(); isa<PHINode>(I); ++I) { 1528204494149b6f846e8f173f525b129f5508076049Andrew Trick PHINode *Phi = cast<PHINode>(I); 1529204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!SE.isSCEVable(Phi->getType())) 1530204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1531204494149b6f846e8f173f525b129f5508076049Andrew Trick 1532204494149b6f846e8f173f525b129f5508076049Andrew Trick PHINode *&OrigPhiRef = ExprToIVMap[SE.getSCEV(Phi)]; 1533204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!OrigPhiRef) { 1534204494149b6f846e8f173f525b129f5508076049Andrew Trick OrigPhiRef = Phi; 1535204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1536204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1537204494149b6f846e8f173f525b129f5508076049Andrew Trick 1538204494149b6f846e8f173f525b129f5508076049Andrew Trick // If one phi derives from the other via GEPs, types may differ. 1539204494149b6f846e8f173f525b129f5508076049Andrew Trick // We could consider adding a bitcast here to handle it. 1540204494149b6f846e8f173f525b129f5508076049Andrew Trick if (OrigPhiRef->getType() != Phi->getType()) 1541204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1542204494149b6f846e8f173f525b129f5508076049Andrew Trick 1543204494149b6f846e8f173f525b129f5508076049Andrew Trick if (BasicBlock *LatchBlock = L->getLoopLatch()) { 1544204494149b6f846e8f173f525b129f5508076049Andrew Trick Instruction *OrigInc = 1545204494149b6f846e8f173f525b129f5508076049Andrew Trick cast<Instruction>(OrigPhiRef->getIncomingValueForBlock(LatchBlock)); 1546204494149b6f846e8f173f525b129f5508076049Andrew Trick Instruction *IsomorphicInc = 1547204494149b6f846e8f173f525b129f5508076049Andrew Trick cast<Instruction>(Phi->getIncomingValueForBlock(LatchBlock)); 1548204494149b6f846e8f173f525b129f5508076049Andrew Trick 1549204494149b6f846e8f173f525b129f5508076049Andrew Trick // If this phi is more canonical, swap it with the original. 1550204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!isExpandedAddRecExprPHI(OrigPhiRef, OrigInc, L, 1551204494149b6f846e8f173f525b129f5508076049Andrew Trick OrigPhiRef->getType()) 1552204494149b6f846e8f173f525b129f5508076049Andrew Trick && isExpandedAddRecExprPHI(Phi, IsomorphicInc, L, Phi->getType())) { 1553204494149b6f846e8f173f525b129f5508076049Andrew Trick std::swap(OrigPhiRef, Phi); 1554204494149b6f846e8f173f525b129f5508076049Andrew Trick std::swap(OrigInc, IsomorphicInc); 1555204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1556204494149b6f846e8f173f525b129f5508076049Andrew Trick // Replacing the congruent phi is sufficient because acyclic redundancy 1557204494149b6f846e8f173f525b129f5508076049Andrew Trick // elimination, CSE/GVN, should handle the rest. However, once SCEV proves 1558204494149b6f846e8f173f525b129f5508076049Andrew Trick // that a phi is congruent, it's often the head of an IV user cycle that 1559204494149b6f846e8f173f525b129f5508076049Andrew Trick // is isomorphic with the original phi. So it's worth eagerly cleaning up 1560204494149b6f846e8f173f525b129f5508076049Andrew Trick // the common case of a single IV increment. 1561204494149b6f846e8f173f525b129f5508076049Andrew Trick if (OrigInc != IsomorphicInc && 1562204494149b6f846e8f173f525b129f5508076049Andrew Trick OrigInc->getType() == IsomorphicInc->getType() && 1563204494149b6f846e8f173f525b129f5508076049Andrew Trick SE.getSCEV(OrigInc) == SE.getSCEV(IsomorphicInc) && 1564204494149b6f846e8f173f525b129f5508076049Andrew Trick hoistStep(OrigInc, IsomorphicInc, DT)) { 1565204494149b6f846e8f173f525b129f5508076049Andrew Trick DEBUG_WITH_TYPE(DebugType, dbgs() 1566204494149b6f846e8f173f525b129f5508076049Andrew Trick << "INDVARS: Eliminated congruent iv.inc: " 1567204494149b6f846e8f173f525b129f5508076049Andrew Trick << *IsomorphicInc << '\n'); 1568204494149b6f846e8f173f525b129f5508076049Andrew Trick IsomorphicInc->replaceAllUsesWith(OrigInc); 1569204494149b6f846e8f173f525b129f5508076049Andrew Trick DeadInsts.push_back(IsomorphicInc); 1570204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1571204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1572204494149b6f846e8f173f525b129f5508076049Andrew Trick DEBUG_WITH_TYPE(DebugType, dbgs() 1573204494149b6f846e8f173f525b129f5508076049Andrew Trick << "INDVARS: Eliminated congruent iv: " << *Phi << '\n'); 1574204494149b6f846e8f173f525b129f5508076049Andrew Trick ++NumElim; 1575204494149b6f846e8f173f525b129f5508076049Andrew Trick Phi->replaceAllUsesWith(OrigPhiRef); 1576204494149b6f846e8f173f525b129f5508076049Andrew Trick DeadInsts.push_back(Phi); 1577204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1578204494149b6f846e8f173f525b129f5508076049Andrew Trick return NumElim; 1579204494149b6f846e8f173f525b129f5508076049Andrew Trick} 1580