ScalarEvolutionExpander.cpp revision dd1f22f25d8496b10cfddedb63d674dd39897bb0
136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman//===- ScalarEvolutionExpander.cpp - Scalar Evolution Analysis --*- C++ -*-===// 236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// The LLVM Compiler Infrastructure 436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman//===----------------------------------------------------------------------===// 936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 1036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// This file contains the implementation of the scalar evolution expander, 1136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// which is used to generate the code corresponding to a given scalar evolution 1236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// expression. 1336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman// 1436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman//===----------------------------------------------------------------------===// 1536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman#include "llvm/Analysis/ScalarEvolutionExpander.h" 17e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling#include "llvm/Analysis/LoopInfo.h" 188d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen#include "llvm/IntrinsicInst.h" 1976f600b205606a055ec35e7d3fd1a99602329d67Owen Anderson#include "llvm/LLVMContext.h" 20c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick#include "llvm/Support/Debug.h" 215be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman#include "llvm/Target/TargetData.h" 22ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick#include "llvm/Target/TargetLowering.h" 234d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman#include "llvm/ADT/STLExtras.h" 24d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 2536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begemanusing namespace llvm; 2636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 2719e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif/// ReuseOrCreateCast - Arrange for there to be a cast of V to Ty at IP, 28485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// reusing an existing cast if a suitable one exists, moving an existing 29485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman/// cast if a suitable one exists but isn't in the right place, or 3019e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif/// creating a new one. 31db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::ReuseOrCreateCast(Value *V, Type *Ty, 32485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction::CastOps Op, 33485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP) { 34485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Check to see if there is already a cast! 35485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); 36f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif UI != E; ++UI) { 37f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif User *U = *UI; 38f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif if (U->getType() == Ty) 3919e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif if (CastInst *CI = dyn_cast<CastInst>(U)) 40485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (CI->getOpcode() == Op) { 41485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // If the cast isn't where we want it, fix it. 42485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (BasicBlock::iterator(CI) != IP) { 43485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast, and leave the old cast in place in case 44485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // it is being used as an insert point. Clear its operand 45485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // so that it doesn't hold anything live. 46485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *NewCI = CastInst::Create(Op, V, Ty, "", IP); 47485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman NewCI->takeName(CI); 48485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->replaceAllUsesWith(NewCI); 49485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->setOperand(0, UndefValue::get(V->getType())); 50485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(NewCI); 51485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return NewCI; 52485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 536f5fed253f58645bf45448893a585ffbd9914989Dan Gohman rememberInstruction(CI); 54485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return CI; 55485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 56f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif } 57485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 58485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast. 59485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *I = CastInst::Create(Op, V, Ty, V->getName(), IP); 60485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(I); 61485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return I; 62485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman} 63485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 64267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// InsertNoopCastOfTo - Insert a cast of V to the specified type, 65267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// which must be possible with a noop cast, doing what we can to share 66267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// the casts. 67db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::InsertNoopCastOfTo(Value *V, Type *Ty) { 68267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction::CastOps Op = CastInst::getCastOpcode(V, false, Ty, false); 69267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert((Op == Instruction::BitCast || 70267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::PtrToInt || 71267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::IntToPtr) && 72267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot perform non-noop casts!"); 73267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert(SE.getTypeSizeInBits(V->getType()) == SE.getTypeSizeInBits(Ty) && 74267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot change sizes!"); 75267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 762d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman // Short-circuit unnecessary bitcasts. 7719154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (Op == Instruction::BitCast) { 7819154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (V->getType() == Ty) 7919154f457696f286b4a597179fa07e3b38ea0310Andrew Trick return V; 8019154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (CastInst *CI = dyn_cast<CastInst>(V)) { 8119154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (CI->getOperand(0)->getType() == Ty) 8219154f457696f286b4a597179fa07e3b38ea0310Andrew Trick return CI->getOperand(0); 8319154f457696f286b4a597179fa07e3b38ea0310Andrew Trick } 8419154f457696f286b4a597179fa07e3b38ea0310Andrew Trick } 85f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman // Short-circuit unnecessary inttoptr<->ptrtoint casts. 86267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if ((Op == Instruction::PtrToInt || Op == Instruction::IntToPtr) && 8780dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) { 88af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if (CastInst *CI = dyn_cast<CastInst>(V)) 89af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if ((CI->getOpcode() == Instruction::PtrToInt || 90af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman CI->getOpcode() == Instruction::IntToPtr) && 91af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getType()) == 92af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getOperand(0)->getType())) 93af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return CI->getOperand(0); 9480dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 9580dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if ((CE->getOpcode() == Instruction::PtrToInt || 9680dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman CE->getOpcode() == Instruction::IntToPtr) && 9780dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getType()) == 9880dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getOperand(0)->getType())) 9980dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman return CE->getOperand(0); 10080dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman } 101f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman 102485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Fold a cast of a constant. 103ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 104baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Op, C, Ty); 1054c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman 106485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the argument at the beginning of the entry block, after 107485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // any bitcasts of other arguments. 108ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Argument *A = dyn_cast<Argument>(V)) { 109485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP = A->getParent()->getEntryBlock().begin(); 110485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman while ((isa<BitCastInst>(IP) && 111485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman isa<Argument>(cast<BitCastInst>(IP)->getOperand(0)) && 112485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman cast<BitCastInst>(IP)->getOperand(0) != A) || 113a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<DbgInfoIntrinsic>(IP) || 114a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(IP)) 115485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman ++IP; 116485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(A, Ty, Op, IP); 117ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 1183913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 119485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the instruction immediately after the instruction. 120ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner Instruction *I = cast<Instruction>(V); 121ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner BasicBlock::iterator IP = I; ++IP; 122ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(I)) 123ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner IP = II->getNormalDest()->begin(); 124a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling while (isa<PHINode>(IP) || isa<DbgInfoIntrinsic>(IP) || 125a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(IP)) 126a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling ++IP; 127485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(I, Ty, Op, IP); 128ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner} 129ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 1307fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// InsertBinop - Insert the specified binary operator, doing a small amount 1317fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// of work to avoid inserting an obviously redundant operation. 132267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, 133267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *LHS, Value *RHS) { 1340f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman // Fold a binop with constant operands. 1350f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(LHS)) 1360f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(RHS)) 137baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, CLHS, CRHS); 1380f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman 1397fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner // Do a quick scan to see if we have this binop nearby. If so, reuse it. 1407fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner unsigned ScanLimit = 6; 141267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 142267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 143267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 144267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 1458a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz --IP; 1468a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz for (; ScanLimit; --IP, --ScanLimit) { 1478d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 1488d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 1498d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 1508d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 1515be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == (unsigned)Opcode && IP->getOperand(0) == LHS && 1525be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(1) == RHS) 1535be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 1548a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (IP == BlockBegin) break; 1558a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz } 1567fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner } 157267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 158087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 159087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 160087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 161087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 162087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 163087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 164087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(LHS) || !L->isLoopInvariant(RHS)) break; 165087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 166087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 167087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 168087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 169087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 170087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 171087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 1728a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // If we haven't found this binop, insert it. 173a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Instruction *BO = cast<Instruction>(Builder.CreateBinOp(Opcode, LHS, RHS)); 174df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel BO->setDebugLoc(SaveInsertPt->getDebugLoc()); 175a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(BO); 176087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 177087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 178087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 179087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 180087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 181cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return BO; 1827fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner} 1837fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner 1844a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// FactorOutConstant - Test if S is divisible by Factor, using signed 185453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// division. If so, update S with Factor divided out and return true. 1863f46a3abeedba8d517b4182de34c821d752db058Dan Gohman/// S need not be evenly divisible if a reasonable remainder can be 1874a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// computed. 188453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// TODO: When ScalarEvolution gets a SCEVSDivExpr, this can be made 189453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// unnecessary; in its place, just signed-divide Ops[i] by the scale and 190453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// check to see if the divide was folded. 1910bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic bool FactorOutConstant(const SCEV *&S, 1920bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *&Remainder, 193c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Factor, 194c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE, 195c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const TargetData *TD) { 196453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Everything is divisible by one. 197c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Factor->isOne()) 198c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 199c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 200c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // x/x == 1. 201c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (S == Factor) { 202deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman S = SE.getConstant(S->getType(), 1); 203453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 204c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 205453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 206453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // For a Constant, check for a multiple of the given factor. 2074a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S)) { 208c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // 0/x == 0. 209c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (C->isZero()) 210453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 211c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Check for divisibility. 212c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *FC = dyn_cast<SCEVConstant>(Factor)) { 213c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt *CI = 214c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt::get(SE.getContext(), 215c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman C->getValue()->getValue().sdiv( 216c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 217c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the quotient is zero and the remainder is non-zero, reject 218c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the value at this scale. It will be considered for subsequent 219c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // smaller scales. 220c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!CI->isZero()) { 221c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Div = SE.getConstant(CI); 222c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = Div; 223c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder = 224c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(Remainder, 225c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().srem( 226c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue()))); 227c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 228c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 229453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 2304a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman } 231453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 232453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In a Mul, check if there is a constant operand which is a multiple 233453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // of the given factor. 234c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S)) { 235c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (TD) { 236c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, the size is known. Check if there is a constant 237c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // operand which is a multiple of the given factor. If so, we can 238c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // factor it. 239c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEVConstant *FC = cast<SCEVConstant>(Factor); 240c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0))) 241c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!C->getValue()->getValue().srem(FC->getValue()->getValue())) { 242f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 243c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[0] = 244c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().sdiv( 245c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 246c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 247c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 248c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 249c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 250c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Without TargetData, check if Factor can be factored out of any of the 251c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Mul's operands. If so, we can just remove it. 252c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) { 253c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *SOp = M->getOperand(i); 254deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(SOp->getType(), 0); 255c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (FactorOutConstant(SOp, Remainder, Factor, SE, TD) && 256c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder->isZero()) { 257f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 258c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[i] = SOp; 259c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 260c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 261c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 262453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 263c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 264c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 265453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 266453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In an AddRec, check if both start and step are divisible. 267453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(S)) { 2680bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Step = A->getStepRecurrence(SE); 269deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *StepRem = SE.getConstant(Step->getType(), 0); 270c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Step, StepRem, Factor, SE, TD)) 2714a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2724a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (!StepRem->isZero()) 2734a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2740bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Start = A->getStart(); 275c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Start, Remainder, Factor, SE, TD)) 276453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 2773228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: can use A->getNoWrapFlags(FlagNW) 2783228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick S = SE.getAddRecExpr(Start, Step, A->getLoop(), SCEV::FlagAnyWrap); 279453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 280453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 281453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 282453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 283453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 284453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 285c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SimplifyAddOperands - Sort and simplify a list of add operands. NumAddRecs 286c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// is the number of SCEVAddRecExprs present, which are kept at the end of 287c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// the list. 288c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 289c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SimplifyAddOperands(SmallVectorImpl<const SCEV *> &Ops, 290db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 291c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 292c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman unsigned NumAddRecs = 0; 293c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = Ops.size(); i > 0 && isa<SCEVAddRecExpr>(Ops[i-1]); --i) 294c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ++NumAddRecs; 295c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Group Ops into non-addrecs and addrecs. 296c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> NoAddRecs(Ops.begin(), Ops.end() - NumAddRecs); 297c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs(Ops.end() - NumAddRecs, Ops.end()); 298c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Let ScalarEvolution sort and simplify the non-addrecs list. 299c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Sum = NoAddRecs.empty() ? 300deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getConstant(Ty, 0) : 301c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(NoAddRecs); 302c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If it returned an add, use the operands. Otherwise it simplified 303c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the sum into a single value, so just use that. 304f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.clear(); 305c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Sum)) 306403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 307f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman else if (!Sum->isZero()) 308f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.push_back(Sum); 309c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Then append the addrecs. 310403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 311c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 312c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 313c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SplitAddRecs - Flatten a list of add operands, moving addrec start values 314c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// out to the top level. For example, convert {a + b,+,c} to a, b, {0,+,d}. 315c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// This helps expose more opportunities for folding parts of the expressions 316c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// into GEP indices. 317c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 318c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SplitAddRecs(SmallVectorImpl<const SCEV *> &Ops, 319db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 320c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 321c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Find the addrecs. 322c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs; 323c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 324c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) { 325c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Start = A->getStart(); 326c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Start->isZero()) break; 327deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Zero = SE.getConstant(Ty, 0); 328c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AddRecs.push_back(SE.getAddRecExpr(Zero, 329c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getStepRecurrence(SE), 3303228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick A->getLoop(), 3313228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: A->getNoWrapFlags(FlagNW) 3323228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 333c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Start)) { 334c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Zero; 335403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 336c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman e += Add->getNumOperands(); 337c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 338c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Start; 339c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 340c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 341c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!AddRecs.empty()) { 342c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Add the addrecs onto the end of the list. 343403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 344c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Resort the operand list, moving any constants to the front. 345c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 346c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 347c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 348c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 3494c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// expandAddToGEP - Expand an addition expression with a pointer type into 3504c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps 3514c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// BasicAliasAnalysis and other passes analyze the result. See the rules 3524c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for getelementptr vs. inttoptr in 3534c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// http://llvm.org/docs/LangRef.html#pointeraliasing 3544c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for details. 35513c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// 3563abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman/// Design note: The correctness of using getelementptr here depends on 3574c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as 3584c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// they may introduce pointer arithmetic which may not be safely converted 3594c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// into getelementptr. 360453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 361453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Design note: It might seem desirable for this function to be more 362453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-aware. If some of the indices are loop-invariant while others 363453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// aren't, it might seem desirable to emit multiple GEPs, keeping the 364453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of the overall computation outside the loop. 365453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// However, there are a few reasons this is not done here. Hoisting simple 366453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// arithmetic is a low-level optimization that often isn't very 367453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// important until late in the optimization process. In fact, passes 368453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// like InstructionCombining will combine GEPs, even if it means 369453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// pushing loop-invariant computation down into loops, so even if the 370453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEPs were split here, the work would quickly be undone. The 371453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// LoopStrengthReduction pass, which is usually run quite late (and 372453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// after the last InstructionCombining pass), takes care of hoisting 373453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of expressions, after considering what 374453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// can be folded using target addressing modes. 375453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 3760bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin, 3770bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *const *op_end, 378db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner PointerType *PTy, 379db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 3805be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *V) { 381db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ElTy = PTy->getElementType(); 3825be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman SmallVector<Value *, 4> GepIndices; 3830bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> Ops(op_begin, op_end); 3845be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman bool AnyNonZeroIndices = false; 3855be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 386c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Split AddRecs up into parts as either of the parts may be usable 387c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // without the other. 388c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SplitAddRecs(Ops, Ty, SE); 389c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 390eb35699e642f2c021f04154bdb4bd90a1afb3baaBob Wilson // Descend down the pointer's type and attempt to convert the other 3915be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // operands into GEP indices, at each level. The first index in a GEP 3925be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // indexes into the array implied by the pointer operand; the rest of 3935be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the indices index into the element or field type selected by the 3945be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // preceding index. 3955be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (;;) { 396c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the scale size is not 0, attempt to factor out a scale for 397c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // array indexing. 3980bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> ScaledOps; 399150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (ElTy->isSized()) { 4004f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const SCEV *ElSize = SE.getSizeOfExpr(ElTy); 401150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ElSize->isZero()) { 402150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SmallVector<const SCEV *, 8> NewOps; 403150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 404150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman const SCEV *Op = Ops[i]; 405deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(Ty, 0); 406150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (FactorOutConstant(Op, Remainder, ElSize, SE, SE.TD)) { 407150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // Op now has ElSize factored out. 408150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman ScaledOps.push_back(Op); 409150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!Remainder->isZero()) 410150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Remainder); 411150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman AnyNonZeroIndices = true; 412150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } else { 413150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // The operand was not divisible, so add it to the list of operands 414150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // we'll scan next iteration. 415150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Ops[i]); 416150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 417150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 418150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // If we made any changes, update Ops. 419150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ScaledOps.empty()) { 420150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman Ops = NewOps; 421150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 4225be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 423c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4245be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 425c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 426c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Record the scaled array index for this level of the type. If 427c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // we didn't find any operands that could be factored, tentatively 428c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // assume that element zero was selected (since the zero offset 429c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // would obviously be folded away). 4305be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *Scaled = ScaledOps.empty() ? 431a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant::getNullValue(Ty) : 4325be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman expandCodeFor(SE.getAddExpr(ScaledOps), Ty); 4335be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman GepIndices.push_back(Scaled); 4345be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4355be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Collect struct field index operands. 436db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner while (StructType *STy = dyn_cast<StructType>(ElTy)) { 437c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman bool FoundFieldNo = false; 438c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // An empty struct has no fields. 439c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (STy->getNumElements() == 0) break; 440c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (SE.TD) { 441c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, field offsets are known. See if a constant offset 442c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // falls within any of the struct fields. 443c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Ops.empty()) break; 4445be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[0])) 4455be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (SE.getTypeSizeInBits(C->getType()) <= 64) { 4465be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const StructLayout &SL = *SE.TD->getStructLayout(STy); 4475be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman uint64_t FullOffset = C->getValue()->getZExtValue(); 4485be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (FullOffset < SL.getSizeInBytes()) { 4495be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(FullOffset); 4501d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson GepIndices.push_back( 4511d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson ConstantInt::get(Type::getInt32Ty(Ty->getContext()), ElIdx)); 4525be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = STy->getTypeAtIndex(ElIdx); 4535be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops[0] = 4546de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman SE.getConstant(Ty, FullOffset - SL.getElementOffset(ElIdx)); 4555be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman AnyNonZeroIndices = true; 456c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 4575be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4585be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 459c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 4600f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman // Without TargetData, just check for an offsetof expression of the 461c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // appropriate struct type. 462c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 4630f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Ops[i])) { 464db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *CTy; 4650f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman Constant *FieldNo; 4664f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (U->isOffsetOf(CTy, FieldNo) && CTy == STy) { 4670f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman GepIndices.push_back(FieldNo); 4680f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman ElTy = 4690f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman STy->getTypeAtIndex(cast<ConstantInt>(FieldNo)->getZExtValue()); 470c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = SE.getConstant(Ty, 0); 471c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AnyNonZeroIndices = true; 472c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 473c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 474c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4750f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman } 4765be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 477c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If no struct field offsets were found, tentatively assume that 478c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // field zero was selected (since the zero offset would obviously 479c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // be folded away). 480c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FoundFieldNo) { 481c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ElTy = STy->getTypeAtIndex(0u); 482c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman GepIndices.push_back( 483c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Constant::getNullValue(Type::getInt32Ty(Ty->getContext()))); 484c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 485c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4865be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 487db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (ArrayType *ATy = dyn_cast<ArrayType>(ElTy)) 4885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = ATy->getElementType(); 489c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman else 490c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 4915be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4925be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4933f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If none of the operands were convertible to proper GEP indices, cast 4945be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the base to i8* and do an ugly getelementptr with that. It's still 4955be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // better than ptrtoint+arithmetic+inttoptr at least. 4965be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (!AnyNonZeroIndices) { 497c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Cast the base to i8*. 4985be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, 499ac53a0b272452013124bfc70480aea5e41b60f40Duncan Sands Type::getInt8PtrTy(Ty->getContext(), PTy->getAddressSpace())); 500c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 501c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Expand the operands for a plain byte offset. 50292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *Idx = expandCodeFor(SE.getAddExpr(Ops), Ty); 5035be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 5045be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Fold a GEP with constant operands. 5055be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(V)) 5065be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(Idx)) 507dab3d29605a5c83db41b28176273ef55961120c1Jay Foad return ConstantExpr::getGetElementPtr(CLHS, CRHS); 5085be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 5095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Do a quick scan to see if we have this GEP nearby. If so, reuse it. 5105be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ScanLimit = 6; 511267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 512267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 513267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 514267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 5155be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman --IP; 5165be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (; ScanLimit; --IP, --ScanLimit) { 5178d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 5188d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 5198d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 5208d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 5215be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == Instruction::GetElementPtr && 5225be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(0) == V && IP->getOperand(1) == Idx) 5235be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 5245be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP == BlockBegin) break; 5255be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5265be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5275be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 528087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 529087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 530087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 531087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 532087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 533087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 534087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V) || !L->isLoopInvariant(Idx)) break; 535087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 536087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 537087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 538087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 539087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 540087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 541087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 542c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Emit a GEP. 543c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *GEP = Builder.CreateGEP(V, Idx, "uglygep"); 544a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 545087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 546087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 547087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 548087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 549087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5505be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return GEP; 5515be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5525be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 553087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 554087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 555087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 556087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 557087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 558087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 559087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V)) break; 560087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 561087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool AnyIndexNotLoopInvariant = false; 562087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<Value *>::const_iterator I = GepIndices.begin(), 563087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E = GepIndices.end(); I != E; ++I) 564087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(*I)) { 565087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman AnyIndexNotLoopInvariant = true; 566087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 567087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 568087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (AnyIndexNotLoopInvariant) 569087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 570087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 571087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 572087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 573087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 574087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 575087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 576087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 577087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 578d6aa02de1076c801ac41295156a2379637976918Dan Gohman // Insert a pretty getelementptr. Note that this GEP is not marked inbounds, 579d6aa02de1076c801ac41295156a2379637976918Dan Gohman // because ScalarEvolution may have changed the address arithmetic to 580d6aa02de1076c801ac41295156a2379637976918Dan Gohman // compute a value which is beyond the end of the allocated object. 581a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Casted = V; 582a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (V->getType() != PTy) 583a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Casted = InsertNoopCastOfTo(Casted, PTy); 584a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *GEP = Builder.CreateGEP(Casted, 5850a2a60ace9b79164b71794ce7ff981171c61e442Jay Foad GepIndices, 586267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "scevgep"); 5875be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops.push_back(SE.getUnknown(GEP)); 588a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 589087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 590087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 591087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 592087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 593087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5945be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return expand(SE.getAddExpr(Ops)); 5955be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman} 5965be18e84766fb495b0bde3c8244c1df459a18683Dan 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 6119c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman/// getRelevantLoop - Get the most relevant loop associated with the given 612087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// expression, according to PickMostRelevantLoop. 6139c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohmanconst Loop *SCEVExpander::getRelevantLoop(const SCEV *S) { 6149c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // Test whether we've already computed the most relevant loop for this SCEV. 6159c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman std::pair<DenseMap<const SCEV *, const Loop *>::iterator, bool> Pair = 6169c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman RelevantLoops.insert(std::make_pair(S, static_cast<const Loop *>(0))); 6179c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (!Pair.second) 6189c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return Pair.first->second; 6199c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman 620087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<SCEVConstant>(S)) 6219c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // A constant has no relevant loops. 622087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 623087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) { 624087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const Instruction *I = dyn_cast<Instruction>(U->getValue())) 6259c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return Pair.first->second = SE.LI->getLoopFor(I->getParent()); 6269c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // A non-instruction has no relevant loops. 627087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 628087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 629087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVNAryExpr *N = dyn_cast<SCEVNAryExpr>(S)) { 630087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *L = 0; 631087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) 632087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman L = AR->getLoop(); 633087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SCEVNAryExpr::op_iterator I = N->op_begin(), E = N->op_end(); 634087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I != E; ++I) 6359c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman L = PickMostRelevantLoop(L, getRelevantLoop(*I), *SE.DT); 6369c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[N] = L; 6379c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman } 6389c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(S)) { 6399c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman const Loop *Result = getRelevantLoop(C->getOperand()); 6409c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[C] = Result; 6419c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman } 6429c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (const SCEVUDivExpr *D = dyn_cast<SCEVUDivExpr>(S)) { 6439c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman const Loop *Result = 6449c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman PickMostRelevantLoop(getRelevantLoop(D->getLHS()), 6459c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman getRelevantLoop(D->getRHS()), 6469c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman *SE.DT); 6479c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[D] = Result; 648087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 649087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman llvm_unreachable("Unexpected SCEV type!"); 6509c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return 0; 651087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 652c4f7ec85ecb760fff2b702c6deb06506b968ba4fDan Gohman 653b35798347ea87b8b6d36155b211016a7769f01abDan Gohmannamespace { 654b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 655087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// LoopCompare - Compare loops by PickMostRelevantLoop. 656087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanclass LoopCompare { 657087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT; 658087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanpublic: 659087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman explicit LoopCompare(DominatorTree &dt) : DT(dt) {} 660087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 661087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool operator()(std::pair<const Loop *, const SCEV *> LHS, 662087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::pair<const Loop *, const SCEV *> RHS) const { 663bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // Keep pointer operands sorted at the end. 664bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (LHS.second->getType()->isPointerTy() != 665bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman RHS.second->getType()->isPointerTy()) 666bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman return LHS.second->getType()->isPointerTy(); 667bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman 668087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Compare loops with PickMostRelevantLoop. 669087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (LHS.first != RHS.first) 670087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return PickMostRelevantLoop(LHS.first, RHS.first, DT) != LHS.first; 671087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 672087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // If one operand is a non-constant negative and the other is not, 673087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // put the non-constant negative on the right so that a sub can 674087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // be used instead of a negate and add. 675f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick if (LHS.second->isNonConstantNegative()) { 676f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick if (!RHS.second->isNonConstantNegative()) 677087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 678f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick } else if (RHS.second->isNonConstantNegative()) 679087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return true; 680087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 681087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Otherwise they are equivalent according to this comparison. 682087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 683c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 684087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman}; 6855be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 686b35798347ea87b8b6d36155b211016a7769f01abDan Gohman} 687b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 688087bd1e3a12893873761736bf0f905a350e9e708Dan GohmanValue *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { 689db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 690e24fa64d52330626553298f56ba5aa702624c282Dan Gohman 691087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the add operands in a loop, along with their associated loops. 692087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal, and 693087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // so that pointer operands are inserted first, which the code below relies on 694087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // to form more involved GEPs. 695087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 696087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVAddExpr::op_iterator> I(S->op_end()), 697087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 6989c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I)); 699087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 700087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants and 701087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // pointer operands precede non-pointer operands. 702087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 703087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 704087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to add all the operands. Hoist as much as possible 705087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops, and form meaningful getelementptrs where possible. 706087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Sum = 0; 707087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 708087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 709087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *CurLoop = I->first; 710087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 711087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Sum) { 712087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 713087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expand(Op); 714087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 715db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner } else if (PointerType *PTy = dyn_cast<PointerType>(Sum->getType())) { 716087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum expression is a pointer. Try to form a getelementptr 717087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // at this level with that as the base. 718087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 719bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman for (; I != E && I->first == CurLoop; ++I) { 720bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // If the operand is SCEVUnknown and not instructions, peek through 721bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // it, to enable more of it to be folded into the GEP. 722bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman const SCEV *X = I->second; 723bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(X)) 724bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (!isa<Instruction>(U->getValue())) 725bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman X = SE.getSCEV(U->getValue()); 726bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman NewOps.push_back(X); 727bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman } 728087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum); 729db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner } else if (PointerType *PTy = dyn_cast<PointerType>(Op->getType())) { 730087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum is an integer, and there's a pointer at this level. 731f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // Try to form a getelementptr. If the running sum is instructions, 732f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // use a SCEVUnknown to avoid re-analyzing them. 733087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 734f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman NewOps.push_back(isa<Instruction>(Sum) ? SE.getUnknown(Sum) : 735f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman SE.getSCEV(Sum)); 736087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (++I; I != E && I->first == CurLoop; ++I) 737087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman NewOps.push_back(I->second); 738087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, expand(Op)); 739f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick } else if (Op->isNonConstantNegative()) { 740087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a negate and add, just do a subtract. 741a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(SE.getNegativeSCEV(Op), Ty); 742087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 743087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Sub, Sum, W); 744087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 745a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 746087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple add. 747a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(Op, Ty); 748087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 749087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 750087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Sum)) std::swap(Sum, W); 751087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Add, Sum, W); 752087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 753a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 7542d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 755087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 756087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Sum; 757e24fa64d52330626553298f56ba5aa702624c282Dan Gohman} 7585be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 759890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) { 760db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 761087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 762087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the mul operands in a loop, along with their associated loops. 763087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal. 764087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 765087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVMulExpr::op_iterator> I(S->op_end()), 766087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 7679c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I)); 768087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 769087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants. 770087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 771087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 772087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to mul all the operands. Hoist as much as possible 773087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops. 774087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Prod = 0; 775087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 776087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 777087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 778087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Prod) { 779087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 780087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = expand(Op); 781087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 782087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (Op->isAllOnesValue()) { 783087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a multiply by negative one, just do a negate. 784087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 785087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Sub, Constant::getNullValue(Ty), Prod); 786087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 787087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else { 788087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple mul. 789087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *W = expandCodeFor(Op, Ty); 790087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 791087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 792087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Prod)) std::swap(Prod, W); 793087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Mul, Prod, W); 794087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 795087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 7962d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 7972d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 798087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Prod; 79936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 80036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 801890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) { 802db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 8032d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 80492fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *LHS = expandCodeFor(S->getLHS(), Ty); 805890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getRHS())) { 8066177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky const APInt &RHS = SC->getValue()->getValue(); 8076177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky if (RHS.isPowerOf2()) 8086177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky return InsertBinop(Instruction::LShr, LHS, 809eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson ConstantInt::get(Ty, RHS.logBase2())); 8106177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky } 8116177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 81292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getRHS(), Ty); 813267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman return InsertBinop(Instruction::UDiv, LHS, RHS); 8146177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky} 8156177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 816453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Move parts of Base into Rest to leave Base with the minimal 817453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// expression that provides a pointer operand suitable for a 818453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEP expansion. 8190bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic void ExposePointerBase(const SCEV *&Base, const SCEV *&Rest, 820453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ScalarEvolution &SE) { 821453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Base)) { 822453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getStart(); 823453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(Rest, 824deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getAddRecExpr(SE.getConstant(A->getType(), 0), 825453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getStepRecurrence(SE), 8263228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick A->getLoop(), 8273228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: A->getNoWrapFlags(FlagNW) 8283228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 829453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 830453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(Base)) { 831453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getOperand(A->getNumOperands()-1); 8320bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> NewAddOps(A->op_begin(), A->op_end()); 833453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman NewAddOps.back() = Rest; 834453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(NewAddOps); 835453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ExposePointerBase(Base, Rest, SE); 836453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 837453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 838453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 839c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// Determine if this is a well-behaved chain of instructions leading back to 840c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// the PHI. If so, it may be reused by expanded expressions. 841c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trickbool SCEVExpander::isNormalAddRecExprPHI(PHINode *PN, Instruction *IncV, 842c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick const Loop *L) { 843c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getNumOperands() == 0 || isa<PHINode>(IncV) || 844c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick (isa<CastInst>(IncV) && !isa<BitCastInst>(IncV))) 845c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 846c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // If any of the operands don't dominate the insert position, bail. 847c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Addrec operands are always loop-invariant, so this can only happen 848c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // if there are instructions which haven't been hoisted. 849c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (L == IVIncInsertLoop) { 850c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (User::op_iterator OI = IncV->op_begin()+1, 851c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick OE = IncV->op_end(); OI != OE; ++OI) 852c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (Instruction *OInst = dyn_cast<Instruction>(OI)) 853c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!SE.DT->dominates(OInst, IVIncInsertPos)) 854c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 855c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 856c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Advance to the next instruction. 857c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 858c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!IncV) 859c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 860c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 861c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->mayHaveSideEffects()) 862c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 863c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 864c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV != PN) 865c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return true; 866c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 867c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return isNormalAddRecExprPHI(PN, IncV, L); 868c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick} 869c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 870c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// Determine if this cyclic phi is in a form that would have been generated by 871c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// LSR. We don't care if the phi was actually expanded in this pass, as long 872c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// as it is in a low-cost form, for example, no implied multiplication. This 873c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// should match any patterns generated by getAddRecExprPHILiterally and 874c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// expandAddtoGEP. 875c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trickbool SCEVExpander::isExpandedAddRecExprPHI(PHINode *PN, Instruction *IncV, 876365c9f1ff55bef134c6b9707f7df44d680ddabeaAndrew Trick const Loop *L) { 87764925c55c65f9345a69fb67db07aa62cfb723577Andrew Trick if (ChainedPhis.count(PN)) 87864925c55c65f9345a69fb67db07aa62cfb723577Andrew Trick return true; 87964925c55c65f9345a69fb67db07aa62cfb723577Andrew Trick 880c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick switch (IncV->getOpcode()) { 881c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Check for a simple Add/Sub or GEP of a loop invariant step. 882c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::Add: 883c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::Sub: 884c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return IncV->getOperand(0) == PN 885c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick && L->isLoopInvariant(IncV->getOperand(1)); 886c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::BitCast: 887c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = dyn_cast<GetElementPtrInst>(IncV->getOperand(0)); 888c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!IncV) 889c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 890c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // fall-thru to GEP handling 891c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::GetElementPtr: { 892c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // This must be a pointer addition of constants (pretty) or some number of 893c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // address-size elements (ugly). 894c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (Instruction::op_iterator I = IncV->op_begin()+1, E = IncV->op_end(); 895c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick I != E; ++I) { 896c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (isa<Constant>(*I)) 897c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 898c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // ugly geps have 2 operands. 899c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // i1* is used by the expander to represent an address-size element. 900c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getNumOperands() != 2) 901c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 902365c9f1ff55bef134c6b9707f7df44d680ddabeaAndrew Trick unsigned AS = cast<PointerType>(IncV->getType())->getAddressSpace(); 903c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getType() != Type::getInt1PtrTy(SE.getContext(), AS) 904c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick && IncV->getType() != Type::getInt8PtrTy(SE.getContext(), AS)) 905c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 90694794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick // Ensure the operands dominate the insertion point. I don't know of a 90794794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick // case when this would not be true, so this is somewhat untested. 90894794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick if (L == IVIncInsertLoop) { 90994794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick for (User::op_iterator OI = IncV->op_begin()+1, 91094794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick OE = IncV->op_end(); OI != OE; ++OI) 91194794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick if (Instruction *OInst = dyn_cast<Instruction>(OI)) 91294794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick if (!SE.DT->dominates(OInst, IVIncInsertPos)) 91394794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick return false; 91494794dd8d38d2572896625fc58e6b0f37809edfaAndrew Trick } 915c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick break; 916c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 917c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 918c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV && IncV->getOpcode() == Instruction::BitCast) 919c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 920c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return IncV == PN; 921c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 922c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick default: 923c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 924c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 925c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick} 926c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 927553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick/// expandIVInc - Expand an IV increment at Builder's current InsertPos. 928553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick/// Typically this is the LatchBlock terminator or IVIncInsertPos, but we may 929553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick/// need to materialize IV increments elsewhere to handle difficult situations. 930553fe05f236f46fe27b7fcfa822b06367d50183eAndrew TrickValue *SCEVExpander::expandIVInc(PHINode *PN, Value *StepV, const Loop *L, 931553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Type *ExpandTy, Type *IntTy, 932553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick bool useSubtract) { 933553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Value *IncV; 934553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If the PHI is a pointer, use a GEP, otherwise use an add or sub. 935553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (ExpandTy->isPointerTy()) { 936553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick PointerType *GEPPtrTy = cast<PointerType>(ExpandTy); 937553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If the step isn't constant, don't use an implicitly scaled GEP, because 938553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // that would require a multiply inside the loop. 939553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (!isa<ConstantInt>(StepV)) 940553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick GEPPtrTy = PointerType::get(Type::getInt1Ty(SE.getContext()), 941553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick GEPPtrTy->getAddressSpace()); 942553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick const SCEV *const StepArray[1] = { SE.getSCEV(StepV) }; 943553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick IncV = expandAddToGEP(StepArray, StepArray+1, GEPPtrTy, IntTy, PN); 944553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (IncV->getType() != PN->getType()) { 945553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick IncV = Builder.CreateBitCast(IncV, PN->getType()); 946553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick rememberInstruction(IncV); 947553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } 948553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } else { 949553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick IncV = useSubtract ? 950553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Builder.CreateSub(PN, StepV, Twine(IVName) + ".iv.next") : 951553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Builder.CreateAdd(PN, StepV, Twine(IVName) + ".iv.next"); 952553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick rememberInstruction(IncV); 953553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } 954553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick return IncV; 955553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick} 956553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick 957a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// getAddRecExprPHILiterally - Helper for expandAddRecExprLiterally. Expand 958a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// the base addrec, which is the addrec without any non-loop-dominating 959a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// values, and return the PHI. 960a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanPHINode * 961a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanSCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized, 962a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L, 963db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ExpandTy, 964db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntTy) { 96593a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer assert((!IVIncInsertLoop||IVIncInsertPos) && "Uninitialized insert position"); 966d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 967a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Reuse a previously-inserted PHI, if present. 968c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick BasicBlock *LatchBlock = L->getLoopLatch(); 969c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (LatchBlock) { 970c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (BasicBlock::iterator I = L->getHeader()->begin(); 971c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick PHINode *PN = dyn_cast<PHINode>(I); ++I) { 972c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!SE.isSCEVable(PN->getType()) || 973c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick (SE.getEffectiveSCEVType(PN->getType()) != 974c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick SE.getEffectiveSCEVType(Normalized->getType())) || 975c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick SE.getSCEV(PN) != Normalized) 976c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 977c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 978c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick Instruction *IncV = 979c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)); 980c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 981c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (LSRMode) { 982365c9f1ff55bef134c6b9707f7df44d680ddabeaAndrew Trick if (!isExpandedAddRecExprPHI(PN, IncV, L)) 983c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 984c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 985c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick else { 986c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!isNormalAddRecExprPHI(PN, IncV, L)) 987c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 988c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 989c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Ok, the add recurrence looks usable. 990c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Remember this PHI, even in post-inc mode. 991c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick InsertedValues.insert(PN); 992c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Remember the increment. 993c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick rememberInstruction(IncV); 994c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (L == IVIncInsertLoop) 99522e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman do { 996c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (SE.DT->dominates(IncV, IVIncInsertPos)) 9979feae9f0de032c66d01d16399a4c5296e38870e3Dan Gohman break; 998c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Make sure the increment is where we want it. But don't move it 999c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // down past a potential existing post-inc user. 1000c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV->moveBefore(IVIncInsertPos); 1001c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IVIncInsertPos = IncV; 1002c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = cast<Instruction>(IncV->getOperand(0)); 100322e621908fdb121474f4806f15ec5c0ce2efeb0aDan Gohman } while (IncV != PN); 1004c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return PN; 1005c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 1006c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 1007a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1008a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Save the original insertion point so we can restore it when we're done. 1009a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1010a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1011a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1012ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // Another AddRec may need to be recursively expanded below. For example, if 1013ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // this AddRec is quadratic, the StepV may itself be an AddRec in this 1014ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // loop. Remove this loop from the PostIncLoops set before expanding such 1015ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // AddRecs. Otherwise, we cannot find a valid position for the step 1016ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // (i.e. StepV can never dominate its loop header). Ideally, we could do 1017ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // SavedIncLoops.swap(PostIncLoops), but we generally have a single element, 1018ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // so it's not worth implementing SmallPtrSet::swap. 1019ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick PostIncLoopSet SavedPostIncLoops = PostIncLoops; 1020ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick PostIncLoops.clear(); 1021ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick 1022a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the start value. 1023a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StartV = expandCodeFor(Normalized->getStart(), ExpandTy, 1024a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman L->getHeader()->begin()); 1025a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1026d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick // StartV must be hoisted into L's preheader to dominate the new phi. 102793a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer assert(!isa<Instruction>(StartV) || 102893a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer SE.DT->properlyDominates(cast<Instruction>(StartV)->getParent(), 102993a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer L->getHeader())); 1030d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 1031553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Expand code for the step value. Do this before creating the PHI so that PHI 1032553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // reuse code doesn't see an incomplete PHI. 1033a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 1034553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If the stride is negative, insert a sub instead of an add for the increment 1035553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // (unless it's a constant, because subtracts of constants are canonicalized 1036553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // to adds). 1037f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick bool useSubtract = !ExpandTy->isPointerTy() && Step->isNonConstantNegative(); 1038553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (useSubtract) 1039a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Step = SE.getNegativeSCEV(Step); 1040553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Expand the step somewhere that dominates the loop header. 1041a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StepV = expandCodeFor(Step, IntTy, L->getHeader()->begin()); 1042a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1043a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the PHI. 1044d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad BasicBlock *Header = L->getHeader(); 1045d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad Builder.SetInsertPoint(Header, Header->begin()); 1046d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad pred_iterator HPB = pred_begin(Header), HPE = pred_end(Header); 10475e7645be4c9dd2193add44d30b5fef8036d7a3ceAndrew Trick PHINode *PN = Builder.CreatePHI(ExpandTy, std::distance(HPB, HPE), 1048dc8e546048db2f7ff5656742b2b26975098a11a0Andrew Trick Twine(IVName) + ".iv"); 1049a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(PN); 1050a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1051a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the step instructions and populate the PHI. 1052d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad for (pred_iterator HPI = HPB; HPI != HPE; ++HPI) { 1053a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *Pred = *HPI; 1054a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1055a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Add a start value. 1056a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!L->contains(Pred)) { 1057a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(StartV, Pred); 1058a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman continue; 1059a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1060a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1061553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Create a step value and add it to the PHI. 1062553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If IVIncInsertLoop is non-null and equal to the addrec's loop, insert the 1063553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // instructions at IVIncInsertPos. 1064a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Instruction *InsertPos = L == IVIncInsertLoop ? 1065a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IVIncInsertPos : Pred->getTerminator(); 1066c5ecbdc1896f1cc089372feef3191ace2f840898Devang Patel Builder.SetInsertPoint(InsertPos); 1067553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Value *IncV = expandIVInc(PN, StepV, L, ExpandTy, IntTy, useSubtract); 1068553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick 1069a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(IncV, Pred); 1070a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1071a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1072a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Restore the original insert point. 1073a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (SaveInsertBB) 1074455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1075a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1076ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // After expanding subexpressions, restore the PostIncLoops set so the caller 1077ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // can ensure that IVIncrement dominates the current uses. 1078ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick PostIncLoops = SavedPostIncLoops; 1079ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick 1080a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Remember this PHI, even in post-inc mode. 1081a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman InsertedValues.insert(PN); 1082a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1083a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return PN; 1084a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1085a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1086a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanValue *SCEVExpander::expandAddRecExprLiterally(const SCEVAddRecExpr *S) { 1087db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *STy = S->getType(); 1088db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntTy = SE.getEffectiveSCEVType(STy); 1089a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L = S->getLoop(); 1090a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1091a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Determine a normalized form of this expression, which is the expression 1092a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // before any post-inc adjustment is made. 1093a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVAddRecExpr *Normalized = S; 1094448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (PostIncLoops.count(L)) { 1095448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman PostIncLoopSet Loops; 1096448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops.insert(L); 1097448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Normalized = 1098448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman cast<SCEVAddRecExpr>(TransformForPostIncUse(Normalize, S, 0, 0, 1099448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops, SE, *SE.DT)); 1100a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1101a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1102a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec start. 1103a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Start = Normalized->getStart(); 1104a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopOffset = 0; 1105dc0e8fb9f9512622f55f73e1a434caa5c0915694Dan Gohman if (!SE.properlyDominates(Start, L->getHeader())) { 1106a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopOffset = Start; 1107deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Start = SE.getConstant(Normalized->getType(), 0); 11083228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized = cast<SCEVAddRecExpr>( 11093228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SE.getAddRecExpr(Start, Normalized->getStepRecurrence(SE), 11103228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized->getLoop(), 11113228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: Normalized->getNoWrapFlags(FlagNW) 11123228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1113a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1114a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1115a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec step. 1116a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 1117a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopScale = 0; 1118dc0e8fb9f9512622f55f73e1a434caa5c0915694Dan Gohman if (!SE.dominates(Step, L->getHeader())) { 1119a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopScale = Step; 1120deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Step = SE.getConstant(Normalized->getType(), 1); 1121a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized = 1122a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start, Step, 11233228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized->getLoop(), 11243228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: Normalized 11253228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // ->getNoWrapFlags(FlagNW) 11263228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1127a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1128a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1129a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand the core addrec. If we need post-loop scaling, force it to 1130a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // expand to an integer type to avoid the need for additional casting. 1131db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ExpandTy = PostLoopScale ? IntTy : STy; 1132a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = getAddRecExprPHILiterally(Normalized, L, ExpandTy, IntTy); 1133a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 11343f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // Accommodate post-inc mode, if necessary. 1135a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Result; 1136448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (!PostIncLoops.count(L)) 1137a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN; 1138a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman else { 1139a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // In PostInc mode, use the post-incremented value. 1140a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *LatchBlock = L->getLoopLatch(); 1141a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman assert(LatchBlock && "PostInc mode requires a unique loop latch!"); 1142a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN->getIncomingValueForBlock(LatchBlock); 114348ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick 114448ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // For an expansion to use the postinc form, the client must call 114548ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // expandCodeFor with an InsertPoint that is either outside the PostIncLoop 114648ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // or dominated by IVIncInsertPos. 1147553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (isa<Instruction>(Result) 1148553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick && !SE.DT->dominates(cast<Instruction>(Result), 1149553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Builder.GetInsertPoint())) { 1150553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // The induction variable's postinc expansion does not dominate this use. 1151553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // IVUsers tries to prevent this case, so it is rare. However, it can 1152553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // happen when an IVUser outside the loop is not dominated by the latch 1153553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // block. Adjusting IVIncInsertPos before expansion begins cannot handle 1154553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // all cases. Consider a phi outide whose operand is replaced during 1155553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // expansion with the value of the postinc user. Without fundamentally 1156553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // changing the way postinc users are tracked, the only remedy is 1157553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // inserting an extra IV increment. StepV might fold into PostLoopOffset, 1158553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // but hopefully expandCodeFor handles that. 1159553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick bool useSubtract = 1160f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick !ExpandTy->isPointerTy() && Step->isNonConstantNegative(); 1161553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (useSubtract) 1162553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Step = SE.getNegativeSCEV(Step); 1163553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Expand the step somewhere that dominates the loop header. 1164553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1165553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1166553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Value *StepV = expandCodeFor(Step, IntTy, L->getHeader()->begin()); 1167553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Restore the insertion point to the place where the caller has 1168553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // determined dominates all uses. 1169553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1170553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Result = expandIVInc(PN, StepV, L, ExpandTy, IntTy, useSubtract); 1171553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } 1172a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1173a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1174a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating scale. 1175a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopScale) { 11760a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1177a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateMul(Result, 1178a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopScale, IntTy)); 1179a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1180a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1181a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1182a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating offset. 1183a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopOffset) { 1184db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (PointerType *PTy = dyn_cast<PointerType>(ExpandTy)) { 1185a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const OffsetArray[1] = { PostLoopOffset }; 1186a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = expandAddToGEP(OffsetArray, OffsetArray+1, PTy, IntTy, Result); 1187a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 11880a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1189a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateAdd(Result, 1190a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopOffset, IntTy)); 1191a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1192a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1193a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1194a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1195a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return Result; 1196a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1197a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1198890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { 1199a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!CanonicalMode) return expandAddRecExprLiterally(S); 1200a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1201db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 120236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Loop *L = S->getLoop(); 120336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12044d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // First check for an existing canonical IV in a suitable type. 12054d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman PHINode *CanonicalIV = 0; 12064d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (PHINode *PN = L->getCanonicalInductionVariable()) 1207133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman if (SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty)) 12084d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV = PN; 12094d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 12104d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Rewrite an AddRec in terms of the canonical induction variable, if 12114d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // its type is more narrow. 12124d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (CanonicalIV && 12134d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(CanonicalIV->getType()) > 12144d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(Ty)) { 1215f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->getNumOperands()); 1216f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman for (unsigned i = 0, e = S->getNumOperands(); i != e; ++i) 1217f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman NewOps[i] = SE.getAnyExtendExpr(S->op_begin()[i], CanonicalIV->getType()); 12183228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Value *V = expand(SE.getAddRecExpr(NewOps, S->getLoop(), 12193228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: S->getNoWrapFlags(FlagNW) 12203228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1221267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1222267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 12234d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman BasicBlock::iterator NewInsertPt = 12247896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner llvm::next(BasicBlock::iterator(cast<Instruction>(V))); 1225a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling while (isa<PHINode>(NewInsertPt) || isa<DbgInfoIntrinsic>(NewInsertPt) || 1226a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(NewInsertPt)) 122708f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach ++NewInsertPt; 12284d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), 0, 12294d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewInsertPt); 1230455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 12314d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman return V; 12324d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman } 12334d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 123436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {X,+,F} --> X + {0,+,F} 1235cfeb6a450632f2a6cd05302633c8c2b8c90cfdfdDan Gohman if (!S->getStart()->isZero()) { 1236f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->op_begin(), S->op_end()); 1237deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman NewOps[0] = SE.getConstant(Ty, 0); 12383228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: can use S->getNoWrapFlags() 12393228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick const SCEV *Rest = SE.getAddRecExpr(NewOps, L, SCEV::FlagAnyWrap); 1240453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 1241453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the 1242453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // comments on expandAddToGEP for details. 1243c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Base = S->getStart(); 1244c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *RestArray[1] = { Rest }; 1245c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Dig into the expression to find the pointer base for a GEP. 1246c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ExposePointerBase(Base, RestArray[0], SE); 1247c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If we found a pointer, expand the AddRec with a GEP. 1248db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (PointerType *PTy = dyn_cast<PointerType>(Base->getType())) { 1249c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Make sure the Base isn't something exotic, such as a multiplied 1250c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // or divided pointer value. In those cases, the result type isn't 1251c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // actually a pointer type. 1252c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!isa<SCEVMulExpr>(Base) && !isa<SCEVUDivExpr>(Base)) { 1253c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *StartV = expand(Base); 1254c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman assert(StartV->getType() == PTy && "Pointer type mismatch for GEP!"); 1255c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return expandAddToGEP(RestArray, RestArray+1, PTy, Ty, StartV); 1256453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1257453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1258453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 125940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Just do a normal add. Pre-expand the operands to suppress folding. 126040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return expand(SE.getAddExpr(SE.getUnknown(expand(S->getStart())), 126140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getUnknown(expand(Rest)))); 126236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 126336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12646ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // If we don't yet have a canonical IV, create one. 12656ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (!CanonicalIV) { 126636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Create and insert the PHI node for the induction variable in the 126736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // specified loop. 126836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman BasicBlock *Header = L->getHeader(); 1269d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad pred_iterator HPB = pred_begin(Header), HPE = pred_end(Header); 12703ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad CanonicalIV = PHINode::Create(Ty, std::distance(HPB, HPE), "indvar", 12713ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad Header->begin()); 12726ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman rememberInstruction(CanonicalIV); 127336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1274eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Constant *One = ConstantInt::get(Ty, 1); 1275d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad for (pred_iterator HPI = HPB; HPI != HPE; ++HPI) { 12767656018c2268285907cfdc106071462a01a73878Gabor Greif BasicBlock *HP = *HPI; 12777656018c2268285907cfdc106071462a01a73878Gabor Greif if (L->contains(HP)) { 12783abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // Insert a unit add instruction right before the terminator 12793abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // corresponding to the back-edge. 12806ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman Instruction *Add = BinaryOperator::CreateAdd(CanonicalIV, One, 12816ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "indvar.next", 12826ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman HP->getTerminator()); 1283df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel Add->setDebugLoc(HP->getTerminator()->getDebugLoc()); 1284a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Add); 12856ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Add, HP); 128683d577490b1473213b6973236110c28e59127956Dan Gohman } else { 12876ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Constant::getNullValue(Ty), HP); 128883d577490b1473213b6973236110c28e59127956Dan Gohman } 12897656018c2268285907cfdc106071462a01a73878Gabor Greif } 129036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 129136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12926ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // {0,+,1} --> Insert a canonical induction variable into the loop! 12936ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (S->isAffine() && S->getOperand(1)->isOne()) { 12946ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) && 12956ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "IVs with types different from the canonical IV should " 12966ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "already have been handled!"); 12976ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman return CanonicalIV; 12986ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman } 12996ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman 13004d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // {0,+,F} --> {0,+,1} * F 130136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1302df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If this is a simple linear addrec, emit it now as a special case. 130340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (S->isAffine()) // {0,+,F} --> i*F 130440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return 130540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman expand(SE.getTruncateOrNoop( 13066ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman SE.getMulExpr(SE.getUnknown(CanonicalIV), 130740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getNoopOrAnyExtend(S->getOperand(1), 13086ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->getType())), 130940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Ty)); 131036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 131136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // If this is a chain of recurrences, turn it into a closed form, using the 131236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // folders, then expandCodeFor the closed form. This allows the folders to 131336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // simplify the expression without having to build a bunch of special code 131436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // into this folder. 13156ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *IH = SE.getUnknown(CanonicalIV); // Get I as a "symbolic" SCEV. 131636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13174d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Promote S up to the canonical IV type, if the cast is foldable. 13180bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *NewS = S; 13196ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *Ext = SE.getNoopOrAnyExtend(S, CanonicalIV->getType()); 13204d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (isa<SCEVAddRecExpr>(Ext)) 13214d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewS = Ext; 13224d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 13230bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE); 1324e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; 132536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13264d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Truncate the result down to the original type, if needed. 13270bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *T = SE.getTruncateOrNoop(V, Ty); 1328469f3cdc13851914f3a766cbd8f701cf8431cacaDan Gohman return expand(T); 132936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 133096fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 1331890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitTruncateExpr(const SCEVTruncateExpr *S) { 1332db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 133392fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 133492fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1335a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateTrunc(V, Ty); 1336a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1337cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 133811f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 133911f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1340890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitZeroExtendExpr(const SCEVZeroExtendExpr *S) { 1341db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 134292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 134392fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1344a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateZExt(V, Ty); 1345a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1346cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 134711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 134811f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1349890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) { 1350db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 135192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 135292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1353a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateSExt(V, Ty); 1354a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1355cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 135611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 135711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1358890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { 13590196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 1360db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = LHS->getType(); 13610196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 13620196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 13630196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 13640196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 13650196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 13660196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 13670196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 136892fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1369a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *ICmp = Builder.CreateICmpSGT(LHS, RHS); 1370a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1371267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "smax"); 1372a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1373cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 1374c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky } 13750196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 13760196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 13770196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 13780196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 1379c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky return LHS; 1380c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky} 1381c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky 1382890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { 13830196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 1384db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = LHS->getType(); 13850196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 13860196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 13870196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 13880196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 13890196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 13900196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 13910196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 139292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1393a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *ICmp = Builder.CreateICmpUGT(LHS, RHS); 1394a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1395267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "umax"); 1396a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1397cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 13983e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky } 13990196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 14000196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 14010196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 14020196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 14033e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky return LHS; 14043e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky} 14053e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky 1406db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::expandCodeFor(const SCEV *SH, Type *Ty, 14076c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Instruction *I) { 14086c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman BasicBlock::iterator IP = I; 14096c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(IP) || isa<DbgInfoIntrinsic>(IP)) 14106c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman ++IP; 14116c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Builder.SetInsertPoint(IP->getParent(), IP); 14126c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman return expandCodeFor(SH, Ty); 14136c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman} 14146c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman 1415db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::expandCodeFor(const SCEV *SH, Type *Ty) { 141611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman // Expand the code for this SCEV. 14172d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *V = expand(SH); 14185be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Ty) { 14195be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman assert(SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(SH->getType()) && 14205be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman "non-trivial casts should be done with the SCEVs directly!"); 14215be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, Ty); 14225be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 14235be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return V; 142411f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 142511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1426890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::expand(const SCEV *S) { 142740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Compute an insertion point for this SCEV object. Hoist the instructions 142840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // as far out in the loop nest as possible. 1429267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *InsertPt = Builder.GetInsertPoint(); 1430267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman for (Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock()); ; 143140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman L = L->getParentLoop()) 143217ead4ff4baceb2c5503f233d0288d363ae44165Dan Gohman if (SE.isLoopInvariant(S, L)) { 143340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (!L) break; 1434e059ee832ca36d65a5fb87b0ac5bcdb0490b15cbDan Gohman if (BasicBlock *Preheader = L->getLoopPreheader()) 143540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = Preheader->getTerminator(); 14360f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick else { 14370f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick // LSR sets the insertion point for AddRec start/step values to the 14380f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick // block start to simplify value reuse, even though it's an invalid 14390f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick // position. SCEVExpander must correct for this in all cases. 14400f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick InsertPt = L->getHeader()->getFirstInsertionPt(); 14410f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick } 144240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } else { 144340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // If the SCEV is computable at this level, insert it into the header 144440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // after the PHIs (and after any other instructions that we've inserted 144540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // there) so that it is guaranteed to dominate any user inside the loop. 14465b6f42f57e730c2d968c313a27fa505a3c3e5efaBill Wendling if (L && SE.hasComputableLoopEvolution(S, L) && !PostIncLoops.count(L)) 14475b6f42f57e730c2d968c313a27fa505a3c3e5efaBill Wendling InsertPt = L->getHeader()->getFirstInsertionPt(); 14486c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(InsertPt) || isa<DbgInfoIntrinsic>(InsertPt)) 14497896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner InsertPt = llvm::next(BasicBlock::iterator(InsertPt)); 145040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman break; 145140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } 145240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1453667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Check to see if we already expanded this here. 1454667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman std::map<std::pair<const SCEV *, Instruction *>, 1455667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman AssertingVH<Value> >::iterator I = 1456667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman InsertedExpressions.find(std::make_pair(S, InsertPt)); 1457267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (I != InsertedExpressions.end()) 1458667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman return I->second; 1459267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 1460267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1461267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1462267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(InsertPt->getParent(), InsertPt); 1463667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1464667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Expand the expression into instructions. 146596fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov Value *V = visit(S); 146640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1467667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Remember the expanded value for this SCEV at this location. 146848ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // 146948ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // This is independent of PostIncLoops. The mapped value simply materializes 147048ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // the expression at this insertion point. If the mapped value happened to be 147148ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // a postinc expansion, it could be reused by a non postinc user, but only if 147248ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // its insertion point was already at the head of the loop. 147348ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick InsertedExpressions[std::make_pair(S, InsertPt)] = V; 1474667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1475455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 147696fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return V; 147796fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov} 14781d09de3eca23267855e28297fcb40de3632ea47bDan Gohman 14791d826a76f591afea445489b9a5485c345e66bf87Dan Gohmanvoid SCEVExpander::rememberInstruction(Value *I) { 148025fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman if (!PostIncLoops.empty()) 148125fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman InsertedPostIncValues.insert(I); 148225fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman else 14831d826a76f591afea445489b9a5485c345e66bf87Dan Gohman InsertedValues.insert(I); 14841d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 14851d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // If we just claimed an existing instruction and that instruction had 14863228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // been the insert point, adjust the insert point forward so that 14871d826a76f591afea445489b9a5485c345e66bf87Dan Gohman // subsequently inserted code will be dominated. 14881d826a76f591afea445489b9a5485c345e66bf87Dan Gohman if (Builder.GetInsertPoint() == I) { 14891d826a76f591afea445489b9a5485c345e66bf87Dan Gohman BasicBlock::iterator It = cast<Instruction>(I); 14906c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman do { ++It; } while (isInsertedInstruction(It) || 14916c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman isa<DbgInfoIntrinsic>(It)); 14921d826a76f591afea445489b9a5485c345e66bf87Dan Gohman Builder.SetInsertPoint(Builder.GetInsertBlock(), It); 14931d826a76f591afea445489b9a5485c345e66bf87Dan Gohman } 14941d826a76f591afea445489b9a5485c345e66bf87Dan Gohman} 14951d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 1496455985501381777db03534c925a35e261e356395Dan Gohmanvoid SCEVExpander::restoreInsertPoint(BasicBlock *BB, BasicBlock::iterator I) { 14973f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If we acquired more instructions since the old insert point was saved, 1498455985501381777db03534c925a35e261e356395Dan Gohman // advance past them. 14996c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman while (isInsertedInstruction(I) || isa<DbgInfoIntrinsic>(I)) ++I; 1500455985501381777db03534c925a35e261e356395Dan Gohman 1501455985501381777db03534c925a35e261e356395Dan Gohman Builder.SetInsertPoint(BB, I); 1502455985501381777db03534c925a35e261e356395Dan Gohman} 1503455985501381777db03534c925a35e261e356395Dan Gohman 15041d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// getOrInsertCanonicalInductionVariable - This method returns the 15051d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// canonical induction variable of the specified type for the specified 15061d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// loop (inserting one if there is none). A canonical induction variable 15071d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// starts at zero and steps by one on each iteration. 15087c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan GohmanPHINode * 15091d09de3eca23267855e28297fcb40de3632ea47bDan GohmanSCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L, 1510db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty) { 1511b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands assert(Ty->isIntegerTy() && "Can only insert integer induction variables!"); 1512133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1513133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Build a SCEV for {0,+,1}<L>. 15143228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // Conservatively use FlagAnyWrap for now. 1515deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *H = SE.getAddRecExpr(SE.getConstant(Ty, 0), 15163228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SE.getConstant(Ty, 1), L, SCEV::FlagAnyWrap); 1517133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1518133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Emit code for it. 1519267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1520267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 15217c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan Gohman PHINode *V = cast<PHINode>(expandCodeFor(H, 0, L->getHeader()->begin())); 1522267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (SaveInsertBB) 1523455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1524133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 152540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return V; 15261d09de3eca23267855e28297fcb40de3632ea47bDan Gohman} 1527204494149b6f846e8f173f525b129f5508076049Andrew Trick 1528204494149b6f846e8f173f525b129f5508076049Andrew Trick/// hoistStep - Attempt to hoist an IV increment above a potential use. 1529204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1530204494149b6f846e8f173f525b129f5508076049Andrew Trick/// To successfully hoist, two criteria must be met: 1531204494149b6f846e8f173f525b129f5508076049Andrew Trick/// - IncV operands dominate InsertPos and 1532204494149b6f846e8f173f525b129f5508076049Andrew Trick/// - InsertPos dominates IncV 1533204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1534204494149b6f846e8f173f525b129f5508076049Andrew Trick/// Meeting the second condition means that we don't need to check all of IncV's 1535204494149b6f846e8f173f525b129f5508076049Andrew Trick/// existing uses (it's moving up in the domtree). 1536204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1537204494149b6f846e8f173f525b129f5508076049Andrew Trick/// This does not yet recursively hoist the operands, although that would 1538204494149b6f846e8f173f525b129f5508076049Andrew Trick/// not be difficult. 1539204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1540204494149b6f846e8f173f525b129f5508076049Andrew Trick/// This does not require a SCEVExpander instance and could be replaced by a 1541204494149b6f846e8f173f525b129f5508076049Andrew Trick/// general code-insertion helper. 1542204494149b6f846e8f173f525b129f5508076049Andrew Trickbool SCEVExpander::hoistStep(Instruction *IncV, Instruction *InsertPos, 1543204494149b6f846e8f173f525b129f5508076049Andrew Trick const DominatorTree *DT) { 1544dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick // Phi nodes are strangely positional but don't follow normal rules for 1545dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick // instruction dominance. Handle them immediately. 1546dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick if (isa<PHINode>(InsertPos)) 1547dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick return isa<PHINode>(IncV); 1548dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick else if (isa<PHINode>(IncV)) 1549dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick return false; 1550dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick 1551204494149b6f846e8f173f525b129f5508076049Andrew Trick if (DT->dominates(IncV, InsertPos)) 1552204494149b6f846e8f173f525b129f5508076049Andrew Trick return true; 1553204494149b6f846e8f173f525b129f5508076049Andrew Trick 1554204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!DT->dominates(InsertPos->getParent(), IncV->getParent())) 1555204494149b6f846e8f173f525b129f5508076049Andrew Trick return false; 1556204494149b6f846e8f173f525b129f5508076049Andrew Trick 1557204494149b6f846e8f173f525b129f5508076049Andrew Trick if (IncV->mayHaveSideEffects()) 1558204494149b6f846e8f173f525b129f5508076049Andrew Trick return false; 1559204494149b6f846e8f173f525b129f5508076049Andrew Trick 1560204494149b6f846e8f173f525b129f5508076049Andrew Trick // Attempt to hoist IncV 1561204494149b6f846e8f173f525b129f5508076049Andrew Trick for (User::op_iterator OI = IncV->op_begin(), OE = IncV->op_end(); 1562204494149b6f846e8f173f525b129f5508076049Andrew Trick OI != OE; ++OI) { 1563204494149b6f846e8f173f525b129f5508076049Andrew Trick Instruction *OInst = dyn_cast<Instruction>(OI); 15643326ec18423716da3a768caae2691e7858913548Andrew Trick if (OInst && (OInst == InsertPos || !DT->dominates(OInst, InsertPos))) 1565204494149b6f846e8f173f525b129f5508076049Andrew Trick return false; 1566204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1567204494149b6f846e8f173f525b129f5508076049Andrew Trick IncV->moveBefore(InsertPos); 1568204494149b6f846e8f173f525b129f5508076049Andrew Trick return true; 1569204494149b6f846e8f173f525b129f5508076049Andrew Trick} 1570204494149b6f846e8f173f525b129f5508076049Andrew Trick 1571139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trick/// Sort values by integer width for replaceCongruentIVs. 1572139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trickstatic bool width_descending(Value *lhs, Value *rhs) { 1573ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Put pointers at the back and make sure pointer < pointer = false. 1574ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (!lhs->getType()->isIntegerTy() || !rhs->getType()->isIntegerTy()) 1575ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick return rhs->getType()->isIntegerTy() && !lhs->getType()->isIntegerTy(); 1576ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick return rhs->getType()->getPrimitiveSizeInBits() 1577ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick < lhs->getType()->getPrimitiveSizeInBits(); 1578ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick} 1579ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick 1580204494149b6f846e8f173f525b129f5508076049Andrew Trick/// replaceCongruentIVs - Check for congruent phis in this loop header and 1581204494149b6f846e8f173f525b129f5508076049Andrew Trick/// replace them with their most canonical representative. Return the number of 1582204494149b6f846e8f173f525b129f5508076049Andrew Trick/// phis eliminated. 1583204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1584204494149b6f846e8f173f525b129f5508076049Andrew Trick/// This does not depend on any SCEVExpander state but should be used in 1585204494149b6f846e8f173f525b129f5508076049Andrew Trick/// the same context that SCEVExpander is used. 1586204494149b6f846e8f173f525b129f5508076049Andrew Trickunsigned SCEVExpander::replaceCongruentIVs(Loop *L, const DominatorTree *DT, 1587ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick SmallVectorImpl<WeakVH> &DeadInsts, 1588ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick const TargetLowering *TLI) { 1589ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Find integer phis in order of increasing width. 1590ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick SmallVector<PHINode*, 8> Phis; 1591ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick for (BasicBlock::iterator I = L->getHeader()->begin(); 1592ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick PHINode *Phi = dyn_cast<PHINode>(I); ++I) { 1593ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Phis.push_back(Phi); 1594ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1595ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (TLI) 1596ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick std::sort(Phis.begin(), Phis.end(), width_descending); 1597ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick 1598204494149b6f846e8f173f525b129f5508076049Andrew Trick unsigned NumElim = 0; 1599204494149b6f846e8f173f525b129f5508076049Andrew Trick DenseMap<const SCEV *, PHINode *> ExprToIVMap; 1600ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Process phis from wide to narrow. Mapping wide phis to the their truncation 1601ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // so narrow phis can reuse them. 1602ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick for (SmallVectorImpl<PHINode*>::const_iterator PIter = Phis.begin(), 1603ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick PEnd = Phis.end(); PIter != PEnd; ++PIter) { 1604ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick PHINode *Phi = *PIter; 1605ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick 1606204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!SE.isSCEVable(Phi->getType())) 1607204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1608204494149b6f846e8f173f525b129f5508076049Andrew Trick 1609204494149b6f846e8f173f525b129f5508076049Andrew Trick PHINode *&OrigPhiRef = ExprToIVMap[SE.getSCEV(Phi)]; 1610204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!OrigPhiRef) { 1611204494149b6f846e8f173f525b129f5508076049Andrew Trick OrigPhiRef = Phi; 1612ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (Phi->getType()->isIntegerTy() && TLI 1613ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick && TLI->isTruncateFree(Phi->getType(), Phis.back()->getType())) { 1614ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // This phi can be freely truncated to the narrowest phi type. Map the 1615ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // truncated expression to it so it will be reused for narrow types. 1616ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick const SCEV *TruncExpr = 1617ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick SE.getTruncateExpr(SE.getSCEV(Phi), Phis.back()->getType()); 1618ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick ExprToIVMap[TruncExpr] = Phi; 1619ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1620204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1621204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1622204494149b6f846e8f173f525b129f5508076049Andrew Trick 1623ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Replacing a pointer phi with an integer phi or vice-versa doesn't make 1624ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // sense. 1625ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigPhiRef->getType()->isPointerTy() != Phi->getType()->isPointerTy()) 1626204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1627204494149b6f846e8f173f525b129f5508076049Andrew Trick 1628204494149b6f846e8f173f525b129f5508076049Andrew Trick if (BasicBlock *LatchBlock = L->getLoopLatch()) { 1629204494149b6f846e8f173f525b129f5508076049Andrew Trick Instruction *OrigInc = 1630204494149b6f846e8f173f525b129f5508076049Andrew Trick cast<Instruction>(OrigPhiRef->getIncomingValueForBlock(LatchBlock)); 1631204494149b6f846e8f173f525b129f5508076049Andrew Trick Instruction *IsomorphicInc = 1632204494149b6f846e8f173f525b129f5508076049Andrew Trick cast<Instruction>(Phi->getIncomingValueForBlock(LatchBlock)); 1633204494149b6f846e8f173f525b129f5508076049Andrew Trick 1634ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // If this phi has the same width but is more canonical, replace the 1635ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // original with it. 1636ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigPhiRef->getType() == Phi->getType() 1637ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick && !isExpandedAddRecExprPHI(OrigPhiRef, OrigInc, L) 1638365c9f1ff55bef134c6b9707f7df44d680ddabeaAndrew Trick && isExpandedAddRecExprPHI(Phi, IsomorphicInc, L)) { 1639204494149b6f846e8f173f525b129f5508076049Andrew Trick std::swap(OrigPhiRef, Phi); 1640204494149b6f846e8f173f525b129f5508076049Andrew Trick std::swap(OrigInc, IsomorphicInc); 1641204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1642204494149b6f846e8f173f525b129f5508076049Andrew Trick // Replacing the congruent phi is sufficient because acyclic redundancy 1643204494149b6f846e8f173f525b129f5508076049Andrew Trick // elimination, CSE/GVN, should handle the rest. However, once SCEV proves 1644204494149b6f846e8f173f525b129f5508076049Andrew Trick // that a phi is congruent, it's often the head of an IV user cycle that 1645139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trick // is isomorphic with the original phi. It's worth eagerly cleaning up the 1646139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trick // common case of a single IV increment so that DeleteDeadPHIs can remove 1647139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trick // cycles that had postinc uses. 1648ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick const SCEV *TruncExpr = SE.getTruncateOrNoop(SE.getSCEV(OrigInc), 1649ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick IsomorphicInc->getType()); 1650ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigInc != IsomorphicInc 165164925c55c65f9345a69fb67db07aa62cfb723577Andrew Trick && TruncExpr == SE.getSCEV(IsomorphicInc) 165264925c55c65f9345a69fb67db07aa62cfb723577Andrew Trick && hoistStep(OrigInc, IsomorphicInc, DT)) { 1653204494149b6f846e8f173f525b129f5508076049Andrew Trick DEBUG_WITH_TYPE(DebugType, dbgs() 1654204494149b6f846e8f173f525b129f5508076049Andrew Trick << "INDVARS: Eliminated congruent iv.inc: " 1655204494149b6f846e8f173f525b129f5508076049Andrew Trick << *IsomorphicInc << '\n'); 1656ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Value *NewInc = OrigInc; 1657ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigInc->getType() != IsomorphicInc->getType()) { 1658dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick Instruction *IP = isa<PHINode>(OrigInc) 1659dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick ? (Instruction*)L->getHeader()->getFirstInsertionPt() 1660dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick : OrigInc->getNextNode(); 1661dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick IRBuilder<> Builder(IP); 1662ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Builder.SetCurrentDebugLocation(IsomorphicInc->getDebugLoc()); 1663ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick NewInc = Builder. 1664ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick CreateTruncOrBitCast(OrigInc, IsomorphicInc->getType(), IVName); 1665ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1666ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick IsomorphicInc->replaceAllUsesWith(NewInc); 1667204494149b6f846e8f173f525b129f5508076049Andrew Trick DeadInsts.push_back(IsomorphicInc); 1668204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1669204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1670204494149b6f846e8f173f525b129f5508076049Andrew Trick DEBUG_WITH_TYPE(DebugType, dbgs() 1671204494149b6f846e8f173f525b129f5508076049Andrew Trick << "INDVARS: Eliminated congruent iv: " << *Phi << '\n'); 1672204494149b6f846e8f173f525b129f5508076049Andrew Trick ++NumElim; 1673ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Value *NewIV = OrigPhiRef; 1674ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigPhiRef->getType() != Phi->getType()) { 1675ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick IRBuilder<> Builder(L->getHeader()->getFirstInsertionPt()); 1676ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Builder.SetCurrentDebugLocation(Phi->getDebugLoc()); 1677ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick NewIV = Builder.CreateTruncOrBitCast(OrigPhiRef, Phi->getType(), IVName); 1678ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1679ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Phi->replaceAllUsesWith(NewIV); 1680204494149b6f846e8f173f525b129f5508076049Andrew Trick DeadInsts.push_back(Phi); 1681204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1682204494149b6f846e8f173f525b129f5508076049Andrew Trick return NumElim; 1683204494149b6f846e8f173f525b129f5508076049Andrew Trick} 1684