ScalarEvolutionExpander.cpp revision 17ead4ff4baceb2c5503f233d0288d363ae44165
136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman//===- ScalarEvolutionExpander.cpp - Scalar Evolution Analysis --*- C++ -*-===// 236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// The LLVM Compiler Infrastructure 436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman//===----------------------------------------------------------------------===// 936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 1036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// This file contains the implementation of the scalar evolution expander, 1136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// which is used to generate the code corresponding to a given scalar evolution 1236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// expression. 1336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 1436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman//===----------------------------------------------------------------------===// 1536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman#include "llvm/Analysis/ScalarEvolutionExpander.h" 17e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling#include "llvm/Analysis/LoopInfo.h" 188d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen#include "llvm/IntrinsicInst.h" 1976f600b205606a055ec35e7d3fd1a99602329d67Owen Anderson#include "llvm/LLVMContext.h" 205be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman#include "llvm/Target/TargetData.h" 214d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman#include "llvm/ADT/STLExtras.h" 2236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begemanusing namespace llvm; 2336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 2419e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif/// ReuseOrCreateCast - Arrange for there to be a cast of V to Ty at IP, 25485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// reusing an existing cast if a suitable one exists, moving an existing 26485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// cast if a suitable one exists but isn't in the right place, or 2719e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif/// creating a new one. 28485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan GohmanValue *SCEVExpander::ReuseOrCreateCast(Value *V, const Type *Ty, 29485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction::CastOps Op, 30485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP) { 31485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Check to see if there is already a cast! 32485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); 33f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif UI != E; ++UI) { 34f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif User *U = *UI; 35f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif if (U->getType() == Ty) 3619e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif if (CastInst *CI = dyn_cast<CastInst>(U)) 37485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (CI->getOpcode() == Op) { 38485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // If the cast isn't where we want it, fix it. 39485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (BasicBlock::iterator(CI) != IP) { 40485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast, and leave the old cast in place in case 41485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // it is being used as an insert point. Clear its operand 42485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // so that it doesn't hold anything live. 43485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *NewCI = CastInst::Create(Op, V, Ty, "", IP); 44485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman NewCI->takeName(CI); 45485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->replaceAllUsesWith(NewCI); 46485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->setOperand(0, UndefValue::get(V->getType())); 47485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(NewCI); 48485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return NewCI; 49485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 506f5fed253f58645bf45448893a585ffbd9914989Dan Gohman rememberInstruction(CI); 51485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return CI; 52485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 53f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif } 54485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 55485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast. 56485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *I = CastInst::Create(Op, V, Ty, V->getName(), IP); 57485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(I); 58485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return I; 59485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman} 60485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 61267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// InsertNoopCastOfTo - Insert a cast of V to the specified type, 62267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// which must be possible with a noop cast, doing what we can to share 63267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// the casts. 64267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertNoopCastOfTo(Value *V, const Type *Ty) { 65267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction::CastOps Op = CastInst::getCastOpcode(V, false, Ty, false); 66267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert((Op == Instruction::BitCast || 67267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::PtrToInt || 68267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::IntToPtr) && 69267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot perform non-noop casts!"); 70267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert(SE.getTypeSizeInBits(V->getType()) == SE.getTypeSizeInBits(Ty) && 71267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot change sizes!"); 72267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 732d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman // Short-circuit unnecessary bitcasts. 74267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (Op == Instruction::BitCast && V->getType() == Ty) 752d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman return V; 762d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 77f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman // Short-circuit unnecessary inttoptr<->ptrtoint casts. 78267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if ((Op == Instruction::PtrToInt || Op == Instruction::IntToPtr) && 7980dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) { 80af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if (CastInst *CI = dyn_cast<CastInst>(V)) 81af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if ((CI->getOpcode() == Instruction::PtrToInt || 82af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman CI->getOpcode() == Instruction::IntToPtr) && 83af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getType()) == 84af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getOperand(0)->getType())) 85af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return CI->getOperand(0); 8680dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 8780dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if ((CE->getOpcode() == Instruction::PtrToInt || 8880dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman CE->getOpcode() == Instruction::IntToPtr) && 8980dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getType()) == 9080dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getOperand(0)->getType())) 9180dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman return CE->getOperand(0); 9280dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman } 93f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman 94485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Fold a cast of a constant. 95ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 96baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Op, C, Ty); 974c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman 98485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the argument at the beginning of the entry block, after 99485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // any bitcasts of other arguments. 100ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Argument *A = dyn_cast<Argument>(V)) { 101485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP = A->getParent()->getEntryBlock().begin(); 102485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman while ((isa<BitCastInst>(IP) && 103485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman isa<Argument>(cast<BitCastInst>(IP)->getOperand(0)) && 104485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman cast<BitCastInst>(IP)->getOperand(0) != A) || 105485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman isa<DbgInfoIntrinsic>(IP)) 106485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman ++IP; 107485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(A, Ty, Op, IP); 108ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 1093913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 110485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the instruction immediately after the instruction. 111ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner Instruction *I = cast<Instruction>(V); 112ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner BasicBlock::iterator IP = I; ++IP; 113ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(I)) 114ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner IP = II->getNormalDest()->begin(); 11508f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach while (isa<PHINode>(IP) || isa<DbgInfoIntrinsic>(IP)) ++IP; 116485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(I, Ty, Op, IP); 117ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner} 118ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 1197fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// InsertBinop - Insert the specified binary operator, doing a small amount 1207fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// of work to avoid inserting an obviously redundant operation. 121267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, 122267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *LHS, Value *RHS) { 1230f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman // Fold a binop with constant operands. 1240f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(LHS)) 1250f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(RHS)) 126baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, CLHS, CRHS); 1270f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman 1287fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner // Do a quick scan to see if we have this binop nearby. If so, reuse it. 1297fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner unsigned ScanLimit = 6; 130267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 131267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 132267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 133267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 1348a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz --IP; 1358a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz for (; ScanLimit; --IP, --ScanLimit) { 1368d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 1378d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 1388d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 1398d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 1405be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == (unsigned)Opcode && IP->getOperand(0) == LHS && 1415be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(1) == RHS) 1425be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 1438a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (IP == BlockBegin) break; 1448a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz } 1457fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner } 146267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 147087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 148087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 149087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 150087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 151087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 152087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 153087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(LHS) || !L->isLoopInvariant(RHS)) break; 154087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 155087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 156087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 157087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 158087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 159087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 160087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 1618a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // If we haven't found this binop, insert it. 162267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *BO = Builder.CreateBinOp(Opcode, LHS, RHS, "tmp"); 163a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(BO); 164087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 165087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 166087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 167087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 168087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 169cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return BO; 1707fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner} 1717fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner 1724a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// FactorOutConstant - Test if S is divisible by Factor, using signed 173453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// division. If so, update S with Factor divided out and return true. 1743f46a3abeedba8d517b4182de34c821d752db058Dan Gohman/// S need not be evenly divisible if a reasonable remainder can be 1754a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// computed. 176453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// TODO: When ScalarEvolution gets a SCEVSDivExpr, this can be made 177453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// unnecessary; in its place, just signed-divide Ops[i] by the scale and 178453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// check to see if the divide was folded. 1790bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic bool FactorOutConstant(const SCEV *&S, 1800bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *&Remainder, 181c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Factor, 182c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE, 183c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const TargetData *TD) { 184453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Everything is divisible by one. 185c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Factor->isOne()) 186c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 187c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 188c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // x/x == 1. 189c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (S == Factor) { 190deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman S = SE.getConstant(S->getType(), 1); 191453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 192c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 193453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 194453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // For a Constant, check for a multiple of the given factor. 1954a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S)) { 196c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // 0/x == 0. 197c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (C->isZero()) 198453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 199c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Check for divisibility. 200c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *FC = dyn_cast<SCEVConstant>(Factor)) { 201c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt *CI = 202c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt::get(SE.getContext(), 203c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman C->getValue()->getValue().sdiv( 204c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 205c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the quotient is zero and the remainder is non-zero, reject 206c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the value at this scale. It will be considered for subsequent 207c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // smaller scales. 208c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!CI->isZero()) { 209c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Div = SE.getConstant(CI); 210c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = Div; 211c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder = 212c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(Remainder, 213c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().srem( 214c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue()))); 215c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 216c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 217453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 2184a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman } 219453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 220453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In a Mul, check if there is a constant operand which is a multiple 221453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // of the given factor. 222c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S)) { 223c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (TD) { 224c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, the size is known. Check if there is a constant 225c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // operand which is a multiple of the given factor. If so, we can 226c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // factor it. 227c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEVConstant *FC = cast<SCEVConstant>(Factor); 228c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0))) 229c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!C->getValue()->getValue().srem(FC->getValue()->getValue())) { 230f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 231c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[0] = 232c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().sdiv( 233c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 234c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 235c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 236c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 237c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 238c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Without TargetData, check if Factor can be factored out of any of the 239c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Mul's operands. If so, we can just remove it. 240c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) { 241c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *SOp = M->getOperand(i); 242deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(SOp->getType(), 0); 243c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (FactorOutConstant(SOp, Remainder, Factor, SE, TD) && 244c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder->isZero()) { 245f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 246c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[i] = SOp; 247c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 248c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 249c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 250453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 251c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 252c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 253453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 254453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In an AddRec, check if both start and step are divisible. 255453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(S)) { 2560bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Step = A->getStepRecurrence(SE); 257deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *StepRem = SE.getConstant(Step->getType(), 0); 258c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Step, StepRem, Factor, SE, TD)) 2594a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2604a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (!StepRem->isZero()) 2614a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2620bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Start = A->getStart(); 263c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Start, Remainder, Factor, SE, TD)) 264453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 265453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman S = SE.getAddRecExpr(Start, Step, A->getLoop()); 266453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 267453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 268453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 269453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 270453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 271453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 272c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SimplifyAddOperands - Sort and simplify a list of add operands. NumAddRecs 273c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// is the number of SCEVAddRecExprs present, which are kept at the end of 274c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// the list. 275c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 276c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SimplifyAddOperands(SmallVectorImpl<const SCEV *> &Ops, 277c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const Type *Ty, 278c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 279c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman unsigned NumAddRecs = 0; 280c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = Ops.size(); i > 0 && isa<SCEVAddRecExpr>(Ops[i-1]); --i) 281c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ++NumAddRecs; 282c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Group Ops into non-addrecs and addrecs. 283c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> NoAddRecs(Ops.begin(), Ops.end() - NumAddRecs); 284c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs(Ops.end() - NumAddRecs, Ops.end()); 285c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Let ScalarEvolution sort and simplify the non-addrecs list. 286c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Sum = NoAddRecs.empty() ? 287deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getConstant(Ty, 0) : 288c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(NoAddRecs); 289c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If it returned an add, use the operands. Otherwise it simplified 290c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the sum into a single value, so just use that. 291f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.clear(); 292c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Sum)) 293403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 294f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman else if (!Sum->isZero()) 295f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.push_back(Sum); 296c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Then append the addrecs. 297403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 298c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 299c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 300c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SplitAddRecs - Flatten a list of add operands, moving addrec start values 301c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// out to the top level. For example, convert {a + b,+,c} to a, b, {0,+,d}. 302c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// This helps expose more opportunities for folding parts of the expressions 303c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// into GEP indices. 304c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 305c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SplitAddRecs(SmallVectorImpl<const SCEV *> &Ops, 306c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const Type *Ty, 307c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 308c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Find the addrecs. 309c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs; 310c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 311c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) { 312c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Start = A->getStart(); 313c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Start->isZero()) break; 314deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Zero = SE.getConstant(Ty, 0); 315c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AddRecs.push_back(SE.getAddRecExpr(Zero, 316c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getStepRecurrence(SE), 317c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getLoop())); 318c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Start)) { 319c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Zero; 320403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 321c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman e += Add->getNumOperands(); 322c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 323c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Start; 324c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 325c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 326c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!AddRecs.empty()) { 327c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Add the addrecs onto the end of the list. 328403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 329c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Resort the operand list, moving any constants to the front. 330c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 331c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 332c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 333c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 3344c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// expandAddToGEP - Expand an addition expression with a pointer type into 3354c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps 3364c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// BasicAliasAnalysis and other passes analyze the result. See the rules 3374c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for getelementptr vs. inttoptr in 3384c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// http://llvm.org/docs/LangRef.html#pointeraliasing 3394c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for details. 34013c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// 3413abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman/// Design note: The correctness of using getelementptr here depends on 3424c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as 3434c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// they may introduce pointer arithmetic which may not be safely converted 3444c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// into getelementptr. 345453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 346453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Design note: It might seem desirable for this function to be more 347453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-aware. If some of the indices are loop-invariant while others 348453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// aren't, it might seem desirable to emit multiple GEPs, keeping the 349453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of the overall computation outside the loop. 350453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// However, there are a few reasons this is not done here. Hoisting simple 351453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// arithmetic is a low-level optimization that often isn't very 352453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// important until late in the optimization process. In fact, passes 353453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// like InstructionCombining will combine GEPs, even if it means 354453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// pushing loop-invariant computation down into loops, so even if the 355453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEPs were split here, the work would quickly be undone. The 356453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// LoopStrengthReduction pass, which is usually run quite late (and 357453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// after the last InstructionCombining pass), takes care of hoisting 358453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of expressions, after considering what 359453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// can be folded using target addressing modes. 360453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 3610bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin, 3620bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *const *op_end, 3635be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const PointerType *PTy, 3645be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const Type *Ty, 3655be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *V) { 3665be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const Type *ElTy = PTy->getElementType(); 3675be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman SmallVector<Value *, 4> GepIndices; 3680bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> Ops(op_begin, op_end); 3695be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman bool AnyNonZeroIndices = false; 3705be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 371c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Split AddRecs up into parts as either of the parts may be usable 372c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // without the other. 373c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SplitAddRecs(Ops, Ty, SE); 374c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 375eb35699e642f2c021f04154bdb4bd90a1afb3baaBob Wilson // Descend down the pointer's type and attempt to convert the other 3765be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // operands into GEP indices, at each level. The first index in a GEP 3775be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // indexes into the array implied by the pointer operand; the rest of 3785be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the indices index into the element or field type selected by the 3795be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // preceding index. 3805be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (;;) { 381c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the scale size is not 0, attempt to factor out a scale for 382c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // array indexing. 3830bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> ScaledOps; 384150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (ElTy->isSized()) { 3854f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const SCEV *ElSize = SE.getSizeOfExpr(ElTy); 386150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ElSize->isZero()) { 387150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SmallVector<const SCEV *, 8> NewOps; 388150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 389150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman const SCEV *Op = Ops[i]; 390deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(Ty, 0); 391150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (FactorOutConstant(Op, Remainder, ElSize, SE, SE.TD)) { 392150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // Op now has ElSize factored out. 393150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman ScaledOps.push_back(Op); 394150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!Remainder->isZero()) 395150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Remainder); 396150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman AnyNonZeroIndices = true; 397150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } else { 398150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // The operand was not divisible, so add it to the list of operands 399150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // we'll scan next iteration. 400150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Ops[i]); 401150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 402150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 403150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // If we made any changes, update Ops. 404150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ScaledOps.empty()) { 405150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman Ops = NewOps; 406150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 4075be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 408c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 410c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 411c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Record the scaled array index for this level of the type. If 412c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // we didn't find any operands that could be factored, tentatively 413c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // assume that element zero was selected (since the zero offset 414c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // would obviously be folded away). 4155be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *Scaled = ScaledOps.empty() ? 416a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant::getNullValue(Ty) : 4175be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman expandCodeFor(SE.getAddExpr(ScaledOps), Ty); 4185be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman GepIndices.push_back(Scaled); 4195be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4205be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Collect struct field index operands. 421c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const StructType *STy = dyn_cast<StructType>(ElTy)) { 422c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman bool FoundFieldNo = false; 423c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // An empty struct has no fields. 424c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (STy->getNumElements() == 0) break; 425c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (SE.TD) { 426c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, field offsets are known. See if a constant offset 427c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // falls within any of the struct fields. 428c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Ops.empty()) break; 4295be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[0])) 4305be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (SE.getTypeSizeInBits(C->getType()) <= 64) { 4315be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const StructLayout &SL = *SE.TD->getStructLayout(STy); 4325be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman uint64_t FullOffset = C->getValue()->getZExtValue(); 4335be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (FullOffset < SL.getSizeInBytes()) { 4345be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(FullOffset); 4351d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson GepIndices.push_back( 4361d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson ConstantInt::get(Type::getInt32Ty(Ty->getContext()), ElIdx)); 4375be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = STy->getTypeAtIndex(ElIdx); 4385be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops[0] = 4396de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman SE.getConstant(Ty, FullOffset - SL.getElementOffset(ElIdx)); 4405be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman AnyNonZeroIndices = true; 441c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 4425be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4435be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 444c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 4450f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman // Without TargetData, just check for an offsetof expression of the 446c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // appropriate struct type. 447c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 4480f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Ops[i])) { 4494f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const Type *CTy; 4500f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman Constant *FieldNo; 4514f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (U->isOffsetOf(CTy, FieldNo) && CTy == STy) { 4520f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman GepIndices.push_back(FieldNo); 4530f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman ElTy = 4540f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman STy->getTypeAtIndex(cast<ConstantInt>(FieldNo)->getZExtValue()); 455c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = SE.getConstant(Ty, 0); 456c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AnyNonZeroIndices = true; 457c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 458c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 459c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4600f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman } 4615be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 462c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If no struct field offsets were found, tentatively assume that 463c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // field zero was selected (since the zero offset would obviously 464c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // be folded away). 465c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FoundFieldNo) { 466c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ElTy = STy->getTypeAtIndex(0u); 467c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman GepIndices.push_back( 468c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Constant::getNullValue(Type::getInt32Ty(Ty->getContext()))); 469c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 470c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4715be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 472c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const ArrayType *ATy = dyn_cast<ArrayType>(ElTy)) 4735be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = ATy->getElementType(); 474c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman else 475c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 4765be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4775be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4783f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If none of the operands were convertible to proper GEP indices, cast 4795be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the base to i8* and do an ugly getelementptr with that. It's still 4805be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // better than ptrtoint+arithmetic+inttoptr at least. 4815be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (!AnyNonZeroIndices) { 482c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Cast the base to i8*. 4835be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, 484ac53a0b272452013124bfc70480aea5e41b60f40Duncan Sands Type::getInt8PtrTy(Ty->getContext(), PTy->getAddressSpace())); 485c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 486c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Expand the operands for a plain byte offset. 48792fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *Idx = expandCodeFor(SE.getAddExpr(Ops), Ty); 4885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4895be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Fold a GEP with constant operands. 4905be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(V)) 4915be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(Idx)) 492baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getGetElementPtr(CLHS, &CRHS, 1); 4935be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4945be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Do a quick scan to see if we have this GEP nearby. If so, reuse it. 4955be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ScanLimit = 6; 496267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 497267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 498267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 499267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 5005be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman --IP; 5015be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (; ScanLimit; --IP, --ScanLimit) { 5028d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 5038d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 5048d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 5058d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 5065be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == Instruction::GetElementPtr && 5075be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(0) == V && IP->getOperand(1) == Idx) 5085be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 5095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP == BlockBegin) break; 5105be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5115be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5125be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 513087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 514087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 515087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 516087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 517087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 518087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 519087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V) || !L->isLoopInvariant(Idx)) break; 520087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 521087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 522087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 523087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 524087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 525087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 526087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 527c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Emit a GEP. 528c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *GEP = Builder.CreateGEP(V, Idx, "uglygep"); 529a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 530087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 531087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 532087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 533087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 534087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5355be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return GEP; 5365be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5375be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 538087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 539087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 540087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 541087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 542087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 543087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 544087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V)) break; 545087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 546087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool AnyIndexNotLoopInvariant = false; 547087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<Value *>::const_iterator I = GepIndices.begin(), 548087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E = GepIndices.end(); I != E; ++I) 549087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(*I)) { 550087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman AnyIndexNotLoopInvariant = true; 551087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 552087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 553087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (AnyIndexNotLoopInvariant) 554087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 555087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 556087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 557087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 558087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 559087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 560087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 561087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 562087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 563d6aa02de1076c801ac41295156a2379637976918Dan Gohman // Insert a pretty getelementptr. Note that this GEP is not marked inbounds, 564d6aa02de1076c801ac41295156a2379637976918Dan Gohman // because ScalarEvolution may have changed the address arithmetic to 565d6aa02de1076c801ac41295156a2379637976918Dan Gohman // compute a value which is beyond the end of the allocated object. 566a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Casted = V; 567a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (V->getType() != PTy) 568a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Casted = InsertNoopCastOfTo(Casted, PTy); 569a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *GEP = Builder.CreateGEP(Casted, 570267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman GepIndices.begin(), 571267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman GepIndices.end(), 572267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "scevgep"); 5735be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops.push_back(SE.getUnknown(GEP)); 574a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 575087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 576087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 577087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 578087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 579087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5805be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return expand(SE.getAddExpr(Ops)); 5815be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman} 5825be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 583a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// isNonConstantNegative - Return true if the specified scev is negated, but 584a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// not a constant. 585a10756ee657a4d43a48cca5c166919093930ed6bDan Gohmanstatic bool isNonConstantNegative(const SCEV *F) { 586a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(F); 587a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!Mul) return false; 588a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 589a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If there is a constant factor, it will be first. 590a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVConstant *SC = dyn_cast<SCEVConstant>(Mul->getOperand(0)); 591a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!SC) return false; 592a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 593a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Return true if the value is negative, this matches things like (-42 * V). 594a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return SC->getValue()->getValue().isNegative(); 595a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 596a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 597087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// PickMostRelevantLoop - Given two loops pick the one that's most relevant for 598087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// SCEV expansion. If they are nested, this is the most nested. If they are 599087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// neighboring, pick the later. 600087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanstatic const Loop *PickMostRelevantLoop(const Loop *A, const Loop *B, 601087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT) { 602087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!A) return B; 603087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!B) return A; 604087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (A->contains(B)) return B; 605087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (B->contains(A)) return A; 606087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(A->getHeader(), B->getHeader())) return B; 607087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(B->getHeader(), A->getHeader())) return A; 608087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return A; // Arbitrarily break the tie. 609087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 610087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 611087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// GetRelevantLoop - Get the most relevant loop associated with the given 612087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// expression, according to PickMostRelevantLoop. 613087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanstatic const Loop *GetRelevantLoop(const SCEV *S, LoopInfo &LI, 614087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT) { 615087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<SCEVConstant>(S)) 616087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 617087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) { 618087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const Instruction *I = dyn_cast<Instruction>(U->getValue())) 619087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return LI.getLoopFor(I->getParent()); 620087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 621087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 622087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVNAryExpr *N = dyn_cast<SCEVNAryExpr>(S)) { 623087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *L = 0; 624087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) 625087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman L = AR->getLoop(); 626087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SCEVNAryExpr::op_iterator I = N->op_begin(), E = N->op_end(); 627087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I != E; ++I) 628087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman L = PickMostRelevantLoop(L, GetRelevantLoop(*I, LI, DT), DT); 629087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return L; 630087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 631087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(S)) 632087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return GetRelevantLoop(C->getOperand(), LI, DT); 633087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVUDivExpr *D = dyn_cast<SCEVUDivExpr>(S)) 634087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return PickMostRelevantLoop(GetRelevantLoop(D->getLHS(), LI, DT), 635087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman GetRelevantLoop(D->getRHS(), LI, DT), 636087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DT); 637087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman llvm_unreachable("Unexpected SCEV type!"); 638087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 639c4f7ec85ecb760fff2b702c6deb06506b968ba4fDan Gohman 640b35798347ea87b8b6d36155b211016a7769f01abDan Gohmannamespace { 641b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 642087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// LoopCompare - Compare loops by PickMostRelevantLoop. 643087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanclass LoopCompare { 644087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT; 645087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanpublic: 646087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman explicit LoopCompare(DominatorTree &dt) : DT(dt) {} 647087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 648087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool operator()(std::pair<const Loop *, const SCEV *> LHS, 649087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::pair<const Loop *, const SCEV *> RHS) const { 650bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // Keep pointer operands sorted at the end. 651bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (LHS.second->getType()->isPointerTy() != 652bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman RHS.second->getType()->isPointerTy()) 653bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman return LHS.second->getType()->isPointerTy(); 654bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman 655087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Compare loops with PickMostRelevantLoop. 656087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (LHS.first != RHS.first) 657087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return PickMostRelevantLoop(LHS.first, RHS.first, DT) != LHS.first; 658087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 659087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // If one operand is a non-constant negative and the other is not, 660087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // put the non-constant negative on the right so that a sub can 661087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // be used instead of a negate and add. 662087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isNonConstantNegative(LHS.second)) { 663087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!isNonConstantNegative(RHS.second)) 664087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 665087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (isNonConstantNegative(RHS.second)) 666087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return true; 667087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 668087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Otherwise they are equivalent according to this comparison. 669087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 670c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 671087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman}; 6725be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 673b35798347ea87b8b6d36155b211016a7769f01abDan Gohman} 674b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 675087bd1e3a12893873761736bf0f905a350e9e708Dan GohmanValue *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { 676087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 677e24fa64d52330626553298f56ba5aa702624c282Dan Gohman 678087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the add operands in a loop, along with their associated loops. 679087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal, and 680087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // so that pointer operands are inserted first, which the code below relies on 681087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // to form more involved GEPs. 682087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 683087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVAddExpr::op_iterator> I(S->op_end()), 684087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 685087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman OpsAndLoops.push_back(std::make_pair(GetRelevantLoop(*I, *SE.LI, *SE.DT), 686087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman *I)); 687087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 688087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants and 689087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // pointer operands precede non-pointer operands. 690087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 691087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 692087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to add all the operands. Hoist as much as possible 693087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops, and form meaningful getelementptrs where possible. 694087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Sum = 0; 695087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 696087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 697087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *CurLoop = I->first; 698087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 699087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Sum) { 700087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 701087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expand(Op); 702087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 703087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (const PointerType *PTy = dyn_cast<PointerType>(Sum->getType())) { 704087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum expression is a pointer. Try to form a getelementptr 705087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // at this level with that as the base. 706087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 707bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman for (; I != E && I->first == CurLoop; ++I) { 708bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // If the operand is SCEVUnknown and not instructions, peek through 709bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // it, to enable more of it to be folded into the GEP. 710bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman const SCEV *X = I->second; 711bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(X)) 712bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (!isa<Instruction>(U->getValue())) 713bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman X = SE.getSCEV(U->getValue()); 714bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman NewOps.push_back(X); 715bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman } 716087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum); 717087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (const PointerType *PTy = dyn_cast<PointerType>(Op->getType())) { 718087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum is an integer, and there's a pointer at this level. 719f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // Try to form a getelementptr. If the running sum is instructions, 720f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // use a SCEVUnknown to avoid re-analyzing them. 721087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 722f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman NewOps.push_back(isa<Instruction>(Sum) ? SE.getUnknown(Sum) : 723f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman SE.getSCEV(Sum)); 724087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (++I; I != E && I->first == CurLoop; ++I) 725087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman NewOps.push_back(I->second); 726087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, expand(Op)); 727087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (isNonConstantNegative(Op)) { 728087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a negate and add, just do a subtract. 729a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(SE.getNegativeSCEV(Op), Ty); 730087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 731087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Sub, Sum, W); 732087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 733a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 734087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple add. 735a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(Op, Ty); 736087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 737087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 738087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Sum)) std::swap(Sum, W); 739087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Add, Sum, W); 740087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 741a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 7422d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 743087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 744087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Sum; 745e24fa64d52330626553298f56ba5aa702624c282Dan Gohman} 7465be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 747890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) { 748af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 749087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 750087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the mul operands in a loop, along with their associated loops. 751087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal. 752087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 753087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVMulExpr::op_iterator> I(S->op_end()), 754087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 755087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman OpsAndLoops.push_back(std::make_pair(GetRelevantLoop(*I, *SE.LI, *SE.DT), 756087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman *I)); 757087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 758087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants. 759087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 760087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 761087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to mul all the operands. Hoist as much as possible 762087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops. 763087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Prod = 0; 764087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 765087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 766087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 767087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Prod) { 768087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 769087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = expand(Op); 770087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 771087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (Op->isAllOnesValue()) { 772087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a multiply by negative one, just do a negate. 773087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 774087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Sub, Constant::getNullValue(Ty), Prod); 775087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 776087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else { 777087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple mul. 778087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *W = expandCodeFor(Op, Ty); 779087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 780087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 781087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Prod)) std::swap(Prod, W); 782087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Mul, Prod, W); 783087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 784087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 7852d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 7862d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 787087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Prod; 78836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 78936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 790890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) { 791af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 7922d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 79392fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *LHS = expandCodeFor(S->getLHS(), Ty); 794890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getRHS())) { 7956177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky const APInt &RHS = SC->getValue()->getValue(); 7966177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky if (RHS.isPowerOf2()) 7976177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky return InsertBinop(Instruction::LShr, LHS, 798eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson ConstantInt::get(Ty, RHS.logBase2())); 7996177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky } 8006177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 80192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getRHS(), Ty); 802267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman return InsertBinop(Instruction::UDiv, LHS, RHS); 8036177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky} 8046177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 805453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Move parts of Base into Rest to leave Base with the minimal 806453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// expression that provides a pointer operand suitable for a 807453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEP expansion. 8080bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic void ExposePointerBase(const SCEV *&Base, const SCEV *&Rest, 809453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ScalarEvolution &SE) { 810453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Base)) { 811453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getStart(); 812453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(Rest, 813deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getAddRecExpr(SE.getConstant(A->getType(), 0), 814453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getStepRecurrence(SE), 815453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getLoop())); 816453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 817453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(Base)) { 818453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getOperand(A->getNumOperands()-1); 8190bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> NewAddOps(A->op_begin(), A->op_end()); 820453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman NewAddOps.back() = Rest; 821453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(NewAddOps); 822453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ExposePointerBase(Base, Rest, SE); 823453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 824453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 825453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 826a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// getAddRecExprPHILiterally - Helper for expandAddRecExprLiterally. Expand 827a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// the base addrec, which is the addrec without any non-loop-dominating 828a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// values, and return the PHI. 829a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanPHINode * 830a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanSCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized, 831a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L, 832a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Type *ExpandTy, 833a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Type *IntTy) { 834a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Reuse a previously-inserted PHI, if present. 835a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman for (BasicBlock::iterator I = L->getHeader()->begin(); 836a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = dyn_cast<PHINode>(I); ++I) 837572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman if (SE.isSCEVable(PN->getType()) && 838572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman (SE.getEffectiveSCEVType(PN->getType()) == 839572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman SE.getEffectiveSCEVType(Normalized->getType())) && 840572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman SE.getSCEV(PN) == Normalized) 841572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman if (BasicBlock *LatchBlock = L->getLoopLatch()) { 842572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman Instruction *IncV = 84322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)); 84422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman 84522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Determine if this is a well-behaved chain of instructions leading 84622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // back to the PHI. It probably will be, if we're scanning an inner 84722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // loop already visited by LSR for example, but it wouldn't have 84822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // to be. 84922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman do { 85022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (IncV->getNumOperands() == 0 || isa<PHINode>(IncV)) { 85122e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = 0; 85222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 85322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } 8549feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // If any of the operands don't dominate the insert position, bail. 8559feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // Addrec operands are always loop-invariant, so this can only happen 8569feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // if there are instructions which haven't been hoisted. 8579feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman for (User::op_iterator OI = IncV->op_begin()+1, 8589feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman OE = IncV->op_end(); OI != OE; ++OI) 8599feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman if (Instruction *OInst = dyn_cast<Instruction>(OI)) 8609feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman if (!SE.DT->dominates(OInst, IVIncInsertPos)) { 8619feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman IncV = 0; 8629feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman break; 8639feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman } 8649feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman if (!IncV) 8659feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman break; 8669feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman // Advance to the next instruction. 86722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 86822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (!IncV) 86922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 87022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (IncV->mayHaveSideEffects()) { 87122e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = 0; 87222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 87322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } 87422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } while (IncV != PN); 87522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman 87622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (IncV) { 87722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Ok, the add recurrence looks usable. 87822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Remember this PHI, even in post-inc mode. 87922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman InsertedValues.insert(PN); 88022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Remember the increment. 88122e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)); 88222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman rememberInstruction(IncV); 88322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (L == IVIncInsertLoop) 88422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman do { 88522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman if (SE.DT->dominates(IncV, IVIncInsertPos)) 88622e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman break; 88722e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // Make sure the increment is where we want it. But don't move it 88822e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman // down past a potential existing post-inc user. 88922e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV->moveBefore(IVIncInsertPos); 89022e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IVIncInsertPos = IncV; 89122e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman IncV = cast<Instruction>(IncV->getOperand(0)); 89222e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } while (IncV != PN); 89322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman return PN; 89422e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } 895572645cf84060c0fc25cb91d38cb9079918b3a88Dan Gohman } 896a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 897a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Save the original insertion point so we can restore it when we're done. 898a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 899a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 900a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 901a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the start value. 902a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StartV = expandCodeFor(Normalized->getStart(), ExpandTy, 903a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman L->getHeader()->begin()); 904a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 905a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the step value. Insert instructions right before the 906a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // terminator corresponding to the back-edge. Do this before creating the PHI 907a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // so that PHI reuse code doesn't see an incomplete PHI. If the stride is 908a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // negative, insert a sub instead of an add for the increment (unless it's a 909a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // constant, because subtracts of constants are canonicalized to adds). 910a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 9111df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands bool isPointer = ExpandTy->isPointerTy(); 912a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman bool isNegative = !isPointer && isNonConstantNegative(Step); 913a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (isNegative) 914a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Step = SE.getNegativeSCEV(Step); 915a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StepV = expandCodeFor(Step, IntTy, L->getHeader()->begin()); 916a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 917a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the PHI. 918a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Builder.SetInsertPoint(L->getHeader(), L->getHeader()->begin()); 919a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = Builder.CreatePHI(ExpandTy, "lsr.iv"); 920a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(PN); 921a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 922a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the step instructions and populate the PHI. 923a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *Header = L->getHeader(); 924a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman for (pred_iterator HPI = pred_begin(Header), HPE = pred_end(Header); 925a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman HPI != HPE; ++HPI) { 926a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *Pred = *HPI; 927a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 928a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Add a start value. 929a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!L->contains(Pred)) { 930a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(StartV, Pred); 931a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman continue; 932a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 933a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 934a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create a step value and add it to the PHI. If IVIncInsertLoop is 935a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // non-null and equal to the addrec's loop, insert the instructions 936a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // at IVIncInsertPos. 937a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Instruction *InsertPos = L == IVIncInsertLoop ? 938a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IVIncInsertPos : Pred->getTerminator(); 939a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Builder.SetInsertPoint(InsertPos->getParent(), InsertPos); 940a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *IncV; 941a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If the PHI is a pointer, use a GEP, otherwise use an add or sub. 942a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (isPointer) { 943a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const PointerType *GEPPtrTy = cast<PointerType>(ExpandTy); 944a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // If the step isn't constant, don't use an implicitly scaled GEP, because 945a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // that would require a multiply inside the loop. 946a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!isa<ConstantInt>(StepV)) 947a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman GEPPtrTy = PointerType::get(Type::getInt1Ty(SE.getContext()), 948a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman GEPPtrTy->getAddressSpace()); 949a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const StepArray[1] = { SE.getSCEV(StepV) }; 950a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = expandAddToGEP(StepArray, StepArray+1, GEPPtrTy, IntTy, PN); 951a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (IncV->getType() != PN->getType()) { 952a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = Builder.CreateBitCast(IncV, PN->getType(), "tmp"); 953a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(IncV); 954a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 955a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 956a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IncV = isNegative ? 957a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Builder.CreateSub(PN, StepV, "lsr.iv.next") : 958a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Builder.CreateAdd(PN, StepV, "lsr.iv.next"); 959a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(IncV); 960a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 961a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(IncV, Pred); 962a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 963a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 964a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Restore the original insert point. 965a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (SaveInsertBB) 966455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 967a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 968a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Remember this PHI, even in post-inc mode. 969a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman InsertedValues.insert(PN); 970a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 971a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return PN; 972a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 973a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 974a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanValue *SCEVExpander::expandAddRecExprLiterally(const SCEVAddRecExpr *S) { 975a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Type *STy = S->getType(); 976a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Type *IntTy = SE.getEffectiveSCEVType(STy); 977a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L = S->getLoop(); 978a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 979a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Determine a normalized form of this expression, which is the expression 980a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // before any post-inc adjustment is made. 981a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVAddRecExpr *Normalized = S; 982448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (PostIncLoops.count(L)) { 983448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman PostIncLoopSet Loops; 984448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops.insert(L); 985448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Normalized = 986448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman cast<SCEVAddRecExpr>(TransformForPostIncUse(Normalize, S, 0, 0, 987448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops, SE, *SE.DT)); 988a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 989a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 990a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec start. 991a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Start = Normalized->getStart(); 992a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopOffset = 0; 993a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!Start->properlyDominates(L->getHeader(), SE.DT)) { 994a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopOffset = Start; 995deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Start = SE.getConstant(Normalized->getType(), 0); 996a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized = 997a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start, 998a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized->getStepRecurrence(SE), 999a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized->getLoop())); 1000a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1001a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1002a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec step. 1003a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 1004a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopScale = 0; 1005948c8a3e3d7349c67e5d9231d9e99b2692623630Dan Gohman if (!Step->dominates(L->getHeader(), SE.DT)) { 1006a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopScale = Step; 1007deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Step = SE.getConstant(Normalized->getType(), 1); 1008a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized = 1009a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start, Step, 1010a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized->getLoop())); 1011a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1012a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1013a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand the core addrec. If we need post-loop scaling, force it to 1014a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // expand to an integer type to avoid the need for additional casting. 1015a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Type *ExpandTy = PostLoopScale ? IntTy : STy; 1016a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = getAddRecExprPHILiterally(Normalized, L, ExpandTy, IntTy); 1017a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 10183f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // Accommodate post-inc mode, if necessary. 1019a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Result; 1020448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (!PostIncLoops.count(L)) 1021a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN; 1022a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman else { 1023a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // In PostInc mode, use the post-incremented value. 1024a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *LatchBlock = L->getLoopLatch(); 1025a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman assert(LatchBlock && "PostInc mode requires a unique loop latch!"); 1026a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN->getIncomingValueForBlock(LatchBlock); 1027a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1028a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1029a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating scale. 1030a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopScale) { 10310a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1032a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateMul(Result, 1033a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopScale, IntTy)); 1034a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1035a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1036a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1037a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating offset. 1038a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopOffset) { 1039a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (const PointerType *PTy = dyn_cast<PointerType>(ExpandTy)) { 1040a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const OffsetArray[1] = { PostLoopOffset }; 1041a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = expandAddToGEP(OffsetArray, OffsetArray+1, PTy, IntTy, Result); 1042a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 10430a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1044a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateAdd(Result, 1045a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopOffset, IntTy)); 1046a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1047a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1048a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1049a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1050a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return Result; 1051a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1052a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1053890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { 1054a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!CanonicalMode) return expandAddRecExprLiterally(S); 1055a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1056af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 105736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Loop *L = S->getLoop(); 105836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 10594d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // First check for an existing canonical IV in a suitable type. 10604d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman PHINode *CanonicalIV = 0; 10614d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (PHINode *PN = L->getCanonicalInductionVariable()) 1062133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman if (SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty)) 10634d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV = PN; 10644d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 10654d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Rewrite an AddRec in terms of the canonical induction variable, if 10664d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // its type is more narrow. 10674d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (CanonicalIV && 10684d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(CanonicalIV->getType()) > 10694d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(Ty)) { 1070f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->getNumOperands()); 1071f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman for (unsigned i = 0, e = S->getNumOperands(); i != e; ++i) 1072f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman NewOps[i] = SE.getAnyExtendExpr(S->op_begin()[i], CanonicalIV->getType()); 1073f3f1be6f065d1b90afe80ca80c9d6473c10deb5aDan Gohman Value *V = expand(SE.getAddRecExpr(NewOps, S->getLoop())); 1074267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1075267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 10764d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman BasicBlock::iterator NewInsertPt = 10777896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner llvm::next(BasicBlock::iterator(cast<Instruction>(V))); 107808f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach while (isa<PHINode>(NewInsertPt) || isa<DbgInfoIntrinsic>(NewInsertPt)) 107908f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach ++NewInsertPt; 10804d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), 0, 10814d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewInsertPt); 1082455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 10834d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman return V; 10844d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman } 10854d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 108636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {X,+,F} --> X + {0,+,F} 1087cfeb6a450632f2a6cd05302633c8c2b8c90cfdfdDan Gohman if (!S->getStart()->isZero()) { 1088f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->op_begin(), S->op_end()); 1089deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman NewOps[0] = SE.getConstant(Ty, 0); 10900bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Rest = SE.getAddRecExpr(NewOps, L); 1091453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 1092453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the 1093453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // comments on expandAddToGEP for details. 1094c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Base = S->getStart(); 1095c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *RestArray[1] = { Rest }; 1096c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Dig into the expression to find the pointer base for a GEP. 1097c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ExposePointerBase(Base, RestArray[0], SE); 1098c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If we found a pointer, expand the AddRec with a GEP. 1099c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const PointerType *PTy = dyn_cast<PointerType>(Base->getType())) { 1100c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Make sure the Base isn't something exotic, such as a multiplied 1101c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // or divided pointer value. In those cases, the result type isn't 1102c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // actually a pointer type. 1103c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!isa<SCEVMulExpr>(Base) && !isa<SCEVUDivExpr>(Base)) { 1104c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *StartV = expand(Base); 1105c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman assert(StartV->getType() == PTy && "Pointer type mismatch for GEP!"); 1106c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return expandAddToGEP(RestArray, RestArray+1, PTy, Ty, StartV); 1107453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1108453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1109453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 111040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Just do a normal add. Pre-expand the operands to suppress folding. 111140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return expand(SE.getAddExpr(SE.getUnknown(expand(S->getStart())), 111240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getUnknown(expand(Rest)))); 111336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 111436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11156ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // If we don't yet have a canonical IV, create one. 11166ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (!CanonicalIV) { 111736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Create and insert the PHI node for the induction variable in the 111836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // specified loop. 111936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman BasicBlock *Header = L->getHeader(); 11206ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV = PHINode::Create(Ty, "indvar", Header->begin()); 11216ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman rememberInstruction(CanonicalIV); 112236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1123eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Constant *One = ConstantInt::get(Ty, 1); 112483d577490b1473213b6973236110c28e59127956Dan Gohman for (pred_iterator HPI = pred_begin(Header), HPE = pred_end(Header); 11257656018c2268285907cfdc106071462a01a73878Gabor Greif HPI != HPE; ++HPI) { 11267656018c2268285907cfdc106071462a01a73878Gabor Greif BasicBlock *HP = *HPI; 11277656018c2268285907cfdc106071462a01a73878Gabor Greif if (L->contains(HP)) { 11283abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // Insert a unit add instruction right before the terminator 11293abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // corresponding to the back-edge. 11306ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman Instruction *Add = BinaryOperator::CreateAdd(CanonicalIV, One, 11316ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "indvar.next", 11326ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman HP->getTerminator()); 1133a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Add); 11346ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Add, HP); 113583d577490b1473213b6973236110c28e59127956Dan Gohman } else { 11366ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Constant::getNullValue(Ty), HP); 113783d577490b1473213b6973236110c28e59127956Dan Gohman } 11387656018c2268285907cfdc106071462a01a73878Gabor Greif } 113936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 114036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11416ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // {0,+,1} --> Insert a canonical induction variable into the loop! 11426ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (S->isAffine() && S->getOperand(1)->isOne()) { 11436ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) && 11446ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "IVs with types different from the canonical IV should " 11456ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "already have been handled!"); 11466ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman return CanonicalIV; 11476ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman } 11486ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman 11494d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // {0,+,F} --> {0,+,1} * F 115036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1151df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If this is a simple linear addrec, emit it now as a special case. 115240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (S->isAffine()) // {0,+,F} --> i*F 115340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return 115440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman expand(SE.getTruncateOrNoop( 11556ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman SE.getMulExpr(SE.getUnknown(CanonicalIV), 115640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getNoopOrAnyExtend(S->getOperand(1), 11576ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->getType())), 115840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Ty)); 115936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 116036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // If this is a chain of recurrences, turn it into a closed form, using the 116136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // folders, then expandCodeFor the closed form. This allows the folders to 116236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // simplify the expression without having to build a bunch of special code 116336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // into this folder. 11646ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *IH = SE.getUnknown(CanonicalIV); // Get I as a "symbolic" SCEV. 116536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11664d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Promote S up to the canonical IV type, if the cast is foldable. 11670bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *NewS = S; 11686ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *Ext = SE.getNoopOrAnyExtend(S, CanonicalIV->getType()); 11694d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (isa<SCEVAddRecExpr>(Ext)) 11704d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewS = Ext; 11714d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 11720bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE); 1173e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; 117436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 11754d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Truncate the result down to the original type, if needed. 11760bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *T = SE.getTruncateOrNoop(V, Ty); 1177469f3cdc13851914f3a766cbd8f701cf8431cacaDan Gohman return expand(T); 117836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 117996fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 1180890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitTruncateExpr(const SCEVTruncateExpr *S) { 1181af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 118292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 118392fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1184267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateTrunc(V, Ty, "tmp"); 1185a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1186cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 118711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 118811f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1189890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitZeroExtendExpr(const SCEVZeroExtendExpr *S) { 1190af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 119192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 119292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1193267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateZExt(V, Ty, "tmp"); 1194a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1195cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 119611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 119711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1198890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) { 1199af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 120092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 120192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1202267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *I = Builder.CreateSExt(V, Ty, "tmp"); 1203a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1204cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 120511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 120611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1207890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { 12080196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 12090196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman const Type *Ty = LHS->getType(); 12100196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 12110196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 12120196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 12130196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 12140196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 12150196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 12160196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 121792fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1218267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *ICmp = Builder.CreateICmpSGT(LHS, RHS, "tmp"); 1219a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1220267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "smax"); 1221a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1222cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 1223c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky } 12240196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 12250196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 12260196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 12270196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 1228c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky return LHS; 1229c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky} 1230c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky 1231890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { 12320196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 12330196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman const Type *Ty = LHS->getType(); 12340196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 12350196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 12360196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 12370196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 12380196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 12390196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 12400196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 124192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1242267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *ICmp = Builder.CreateICmpUGT(LHS, RHS, "tmp"); 1243a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1244267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "umax"); 1245a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1246cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 12473e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky } 12480196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 12490196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 12500196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 12510196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 12523e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky return LHS; 12533e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky} 12543e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky 12556c7ed6b54949949806797bafdf545fbfecb2cef5Dan GohmanValue *SCEVExpander::expandCodeFor(const SCEV *SH, const Type *Ty, 12566c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Instruction *I) { 12576c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman BasicBlock::iterator IP = I; 12586c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(IP) || isa<DbgInfoIntrinsic>(IP)) 12596c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman ++IP; 12606c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Builder.SetInsertPoint(IP->getParent(), IP); 12616c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman return expandCodeFor(SH, Ty); 12626c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman} 12636c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman 12640bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandCodeFor(const SCEV *SH, const Type *Ty) { 126511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman // Expand the code for this SCEV. 12662d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *V = expand(SH); 12675be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Ty) { 12685be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman assert(SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(SH->getType()) && 12695be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman "non-trivial casts should be done with the SCEVs directly!"); 12705be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, Ty); 12715be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 12725be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return V; 127311f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 127411f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1275890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::expand(const SCEV *S) { 127640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Compute an insertion point for this SCEV object. Hoist the instructions 127740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // as far out in the loop nest as possible. 1278267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *InsertPt = Builder.GetInsertPoint(); 1279267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman for (Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock()); ; 128040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman L = L->getParentLoop()) 128117ead4ff4baceb2c5503f233d0288d363ae44165Dan Gohman if (SE.isLoopInvariant(S, L)) { 128240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (!L) break; 1283e059ee832ca36d65a5fb87b0ac5bcdb0490b15cbDan Gohman if (BasicBlock *Preheader = L->getLoopPreheader()) 128440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = Preheader->getTerminator(); 128540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } else { 128640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // If the SCEV is computable at this level, insert it into the header 128740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // after the PHIs (and after any other instructions that we've inserted 128840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // there) so that it is guaranteed to dominate any user inside the loop. 128917ead4ff4baceb2c5503f233d0288d363ae44165Dan Gohman if (L && SE.hasComputableLoopEvolution(S, L) && !PostIncLoops.count(L)) 129040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = L->getHeader()->getFirstNonPHI(); 12916c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(InsertPt) || isa<DbgInfoIntrinsic>(InsertPt)) 12927896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner InsertPt = llvm::next(BasicBlock::iterator(InsertPt)); 129340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman break; 129440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } 129540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1296667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Check to see if we already expanded this here. 1297667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman std::map<std::pair<const SCEV *, Instruction *>, 1298667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman AssertingVH<Value> >::iterator I = 1299667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman InsertedExpressions.find(std::make_pair(S, InsertPt)); 1300267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (I != InsertedExpressions.end()) 1301667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman return I->second; 1302267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 1303267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1304267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1305267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(InsertPt->getParent(), InsertPt); 1306667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1307667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Expand the expression into instructions. 130896fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov Value *V = visit(S); 130940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1310667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Remember the expanded value for this SCEV at this location. 1311448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (PostIncLoops.empty()) 1312a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman InsertedExpressions[std::make_pair(S, InsertPt)] = V; 1313667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1314455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 131596fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return V; 131696fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov} 13171d09de3eca23267855e28297fcb40de3632ea47bDan Gohman 13181d826a76f591afea445489b9a5485c345e66bf87Dan Gohmanvoid SCEVExpander::rememberInstruction(Value *I) { 131925fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman if (!PostIncLoops.empty()) 132025fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman InsertedPostIncValues.insert(I); 132125fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman else 13221d826a76f591afea445489b9a5485c345e66bf87Dan Gohman InsertedValues.insert(I); 13231d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 13241d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // If we just claimed an existing instruction and that instruction had 13251d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // been the insert point, adjust the insert point forward so that 13261d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // subsequently inserted code will be dominated. 13271d826a76f591afea445489b9a5485c345e66bf87Dan Gohman if (Builder.GetInsertPoint() == I) { 13281d826a76f591afea445489b9a5485c345e66bf87Dan Gohman BasicBlock::iterator It = cast<Instruction>(I); 13296c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman do { ++It; } while (isInsertedInstruction(It) || 13306c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman isa<DbgInfoIntrinsic>(It)); 13311d826a76f591afea445489b9a5485c345e66bf87Dan Gohman Builder.SetInsertPoint(Builder.GetInsertBlock(), It); 13321d826a76f591afea445489b9a5485c345e66bf87Dan Gohman } 13331d826a76f591afea445489b9a5485c345e66bf87Dan Gohman} 13341d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 1335455985501381777db03534c925a35e261e356395Dan Gohmanvoid SCEVExpander::restoreInsertPoint(BasicBlock *BB, BasicBlock::iterator I) { 13363f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If we acquired more instructions since the old insert point was saved, 1337455985501381777db03534c925a35e261e356395Dan Gohman // advance past them. 13386c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(I) || isa<DbgInfoIntrinsic>(I)) ++I; 1339455985501381777db03534c925a35e261e356395Dan Gohman 1340455985501381777db03534c925a35e261e356395Dan Gohman Builder.SetInsertPoint(BB, I); 1341455985501381777db03534c925a35e261e356395Dan Gohman} 1342455985501381777db03534c925a35e261e356395Dan Gohman 13431d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// getOrInsertCanonicalInductionVariable - This method returns the 13441d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// canonical induction variable of the specified type for the specified 13451d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// loop (inserting one if there is none). A canonical induction variable 13461d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// starts at zero and steps by one on each iteration. 13477c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan GohmanPHINode * 13481d09de3eca23267855e28297fcb40de3632ea47bDan GohmanSCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L, 13491d09de3eca23267855e28297fcb40de3632ea47bDan Gohman const Type *Ty) { 1350b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands assert(Ty->isIntegerTy() && "Can only insert integer induction variables!"); 1351133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1352133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Build a SCEV for {0,+,1}<L>. 1353deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *H = SE.getAddRecExpr(SE.getConstant(Ty, 0), 1354deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getConstant(Ty, 1), L); 1355133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1356133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Emit code for it. 1357267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1358267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 13597c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan Gohman PHINode *V = cast<PHINode>(expandCodeFor(H, 0, L->getHeader()->begin())); 1360267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (SaveInsertBB) 1361455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1362133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 136340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return V; 13641d09de3eca23267855e28297fcb40de3632ea47bDan Gohman} 1365