ScalarEvolutionExpander.cpp revision ef4c80e07baf02dd2a8f08db49c5634a06d3ca1e
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) { 34ef4c80e07baf02dd2a8f08db49c5634a06d3ca1eRafael Espindola // All new or reused instructions must strictly dominate the Builder's 35ef4c80e07baf02dd2a8f08db49c5634a06d3ca1eRafael Espindola // InsertPt to ensure that the expression's expansion dominates its uses. 36ef4c80e07baf02dd2a8f08db49c5634a06d3ca1eRafael Espindola // Assert that the requested insertion point works at least for new 37ef4c80e07baf02dd2a8f08db49c5634a06d3ca1eRafael Espindola // instructions. 38ef4c80e07baf02dd2a8f08db49c5634a06d3ca1eRafael Espindola assert(SE.DT->dominates(IP, Builder.GetInsertPoint())); 39ef4c80e07baf02dd2a8f08db49c5634a06d3ca1eRafael Espindola 40485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Check to see if there is already a cast! 41485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); 42f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif UI != E; ++UI) { 43f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif User *U = *UI; 44f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif if (U->getType() == Ty) 4519e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif if (CastInst *CI = dyn_cast<CastInst>(U)) 46485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (CI->getOpcode() == Op) { 47ef4c80e07baf02dd2a8f08db49c5634a06d3ca1eRafael Espindola // If the cast isn't where we want it, fix it. 48b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (BasicBlock::iterator(CI) != IP 49b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick || IP == Builder.GetInsertPoint()) { 50485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast, and leave the old cast in place in case 51485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // it is being used as an insert point. Clear its operand 52485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // so that it doesn't hold anything live. 53485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *NewCI = CastInst::Create(Op, V, Ty, "", IP); 54485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman NewCI->takeName(CI); 55485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->replaceAllUsesWith(NewCI); 56485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->setOperand(0, UndefValue::get(V->getType())); 57485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(NewCI); 58485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return NewCI; 59485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 606f5fed253f58645bf45448893a585ffbd9914989Dan Gohman rememberInstruction(CI); 61485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return CI; 62485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 63f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif } 64485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 65485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast. 66485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *I = CastInst::Create(Op, V, Ty, V->getName(), IP); 67485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(I); 68485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return I; 69485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman} 70485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 71267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// InsertNoopCastOfTo - Insert a cast of V to the specified type, 72267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// which must be possible with a noop cast, doing what we can to share 73267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// the casts. 74db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::InsertNoopCastOfTo(Value *V, Type *Ty) { 75267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction::CastOps Op = CastInst::getCastOpcode(V, false, Ty, false); 76267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert((Op == Instruction::BitCast || 77267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::PtrToInt || 78267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::IntToPtr) && 79267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot perform non-noop casts!"); 80267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert(SE.getTypeSizeInBits(V->getType()) == SE.getTypeSizeInBits(Ty) && 81267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot change sizes!"); 82267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 832d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman // Short-circuit unnecessary bitcasts. 8419154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (Op == Instruction::BitCast) { 8519154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (V->getType() == Ty) 8619154f457696f286b4a597179fa07e3b38ea0310Andrew Trick return V; 8719154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (CastInst *CI = dyn_cast<CastInst>(V)) { 8819154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (CI->getOperand(0)->getType() == Ty) 8919154f457696f286b4a597179fa07e3b38ea0310Andrew Trick return CI->getOperand(0); 9019154f457696f286b4a597179fa07e3b38ea0310Andrew Trick } 9119154f457696f286b4a597179fa07e3b38ea0310Andrew Trick } 92f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman // Short-circuit unnecessary inttoptr<->ptrtoint casts. 93267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if ((Op == Instruction::PtrToInt || Op == Instruction::IntToPtr) && 9480dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) { 95af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if (CastInst *CI = dyn_cast<CastInst>(V)) 96af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if ((CI->getOpcode() == Instruction::PtrToInt || 97af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman CI->getOpcode() == Instruction::IntToPtr) && 98af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getType()) == 99af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getOperand(0)->getType())) 100af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return CI->getOperand(0); 10180dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 10280dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if ((CE->getOpcode() == Instruction::PtrToInt || 10380dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman CE->getOpcode() == Instruction::IntToPtr) && 10480dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getType()) == 10580dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getOperand(0)->getType())) 10680dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman return CE->getOperand(0); 10780dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman } 108f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman 109485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Fold a cast of a constant. 110ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 111baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Op, C, Ty); 1124c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman 113485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the argument at the beginning of the entry block, after 114485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // any bitcasts of other arguments. 115ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Argument *A = dyn_cast<Argument>(V)) { 116485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP = A->getParent()->getEntryBlock().begin(); 117485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman while ((isa<BitCastInst>(IP) && 118485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman isa<Argument>(cast<BitCastInst>(IP)->getOperand(0)) && 119485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman cast<BitCastInst>(IP)->getOperand(0) != A) || 120a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<DbgInfoIntrinsic>(IP) || 121a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(IP)) 122485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman ++IP; 123485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(A, Ty, Op, IP); 124ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 1253913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 126485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the instruction immediately after the instruction. 127ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner Instruction *I = cast<Instruction>(V); 128ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner BasicBlock::iterator IP = I; ++IP; 129ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(I)) 130ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner IP = II->getNormalDest()->begin(); 131ef4c80e07baf02dd2a8f08db49c5634a06d3ca1eRafael Espindola while (isa<PHINode>(IP) || isa<LandingPadInst>(IP)) 132a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling ++IP; 133485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(I, Ty, Op, IP); 134ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner} 135ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 1367fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// InsertBinop - Insert the specified binary operator, doing a small amount 1377fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// of work to avoid inserting an obviously redundant operation. 138267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, 139267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *LHS, Value *RHS) { 1400f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman // Fold a binop with constant operands. 1410f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(LHS)) 1420f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(RHS)) 143baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, CLHS, CRHS); 1440f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman 1457fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner // Do a quick scan to see if we have this binop nearby. If so, reuse it. 1467fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner unsigned ScanLimit = 6; 147267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 148267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 149267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 150267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 1518a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz --IP; 1528a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz for (; ScanLimit; --IP, --ScanLimit) { 1538d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 1548d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 1558d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 1568d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 1575be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == (unsigned)Opcode && IP->getOperand(0) == LHS && 1585be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(1) == RHS) 1595be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 1608a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (IP == BlockBegin) break; 1618a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz } 1627fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner } 163267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 164087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 165087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 166087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 167087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 168087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 169087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 170087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(LHS) || !L->isLoopInvariant(RHS)) break; 171087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 172087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 173087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 174087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 175087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 176087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 177087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 1788a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // If we haven't found this binop, insert it. 179a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Instruction *BO = cast<Instruction>(Builder.CreateBinOp(Opcode, LHS, RHS)); 180df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel BO->setDebugLoc(SaveInsertPt->getDebugLoc()); 181a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(BO); 182087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 183087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 184087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 185087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 186087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 187cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return BO; 1887fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner} 1897fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner 1904a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// FactorOutConstant - Test if S is divisible by Factor, using signed 191453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// division. If so, update S with Factor divided out and return true. 1923f46a3abeedba8d517b4182de34c821d752db058Dan Gohman/// S need not be evenly divisible if a reasonable remainder can be 1934a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// computed. 194453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// TODO: When ScalarEvolution gets a SCEVSDivExpr, this can be made 195453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// unnecessary; in its place, just signed-divide Ops[i] by the scale and 196453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// check to see if the divide was folded. 1970bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic bool FactorOutConstant(const SCEV *&S, 1980bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *&Remainder, 199c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Factor, 200c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE, 201c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const TargetData *TD) { 202453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Everything is divisible by one. 203c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Factor->isOne()) 204c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 205c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 206c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // x/x == 1. 207c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (S == Factor) { 208deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman S = SE.getConstant(S->getType(), 1); 209453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 210c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 211453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 212453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // For a Constant, check for a multiple of the given factor. 2134a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S)) { 214c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // 0/x == 0. 215c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (C->isZero()) 216453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 217c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Check for divisibility. 218c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *FC = dyn_cast<SCEVConstant>(Factor)) { 219c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt *CI = 220c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt::get(SE.getContext(), 221c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman C->getValue()->getValue().sdiv( 222c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 223c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the quotient is zero and the remainder is non-zero, reject 224c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the value at this scale. It will be considered for subsequent 225c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // smaller scales. 226c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!CI->isZero()) { 227c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Div = SE.getConstant(CI); 228c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = Div; 229c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder = 230c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(Remainder, 231c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().srem( 232c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue()))); 233c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 234c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 235453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 2364a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman } 237453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 238453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In a Mul, check if there is a constant operand which is a multiple 239453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // of the given factor. 240c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S)) { 241c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (TD) { 242c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, the size is known. Check if there is a constant 243c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // operand which is a multiple of the given factor. If so, we can 244c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // factor it. 245c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEVConstant *FC = cast<SCEVConstant>(Factor); 246c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0))) 247c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!C->getValue()->getValue().srem(FC->getValue()->getValue())) { 248f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 249c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[0] = 250c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().sdiv( 251c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 252c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 253c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 254c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 255c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 256c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Without TargetData, check if Factor can be factored out of any of the 257c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Mul's operands. If so, we can just remove it. 258c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) { 259c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *SOp = M->getOperand(i); 260deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(SOp->getType(), 0); 261c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (FactorOutConstant(SOp, Remainder, Factor, SE, TD) && 262c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder->isZero()) { 263f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 264c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[i] = SOp; 265c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 266c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 267c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 268453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 269c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 270c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 271453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 272453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In an AddRec, check if both start and step are divisible. 273453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(S)) { 2740bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Step = A->getStepRecurrence(SE); 275deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *StepRem = SE.getConstant(Step->getType(), 0); 276c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Step, StepRem, Factor, SE, TD)) 2774a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2784a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (!StepRem->isZero()) 2794a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2800bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Start = A->getStart(); 281c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Start, Remainder, Factor, SE, TD)) 282453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 2833228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: can use A->getNoWrapFlags(FlagNW) 2843228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick S = SE.getAddRecExpr(Start, Step, A->getLoop(), SCEV::FlagAnyWrap); 285453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 286453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 287453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 288453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 289453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 290453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 291c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SimplifyAddOperands - Sort and simplify a list of add operands. NumAddRecs 292c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// is the number of SCEVAddRecExprs present, which are kept at the end of 293c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// the list. 294c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 295c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SimplifyAddOperands(SmallVectorImpl<const SCEV *> &Ops, 296db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 297c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 298c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman unsigned NumAddRecs = 0; 299c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = Ops.size(); i > 0 && isa<SCEVAddRecExpr>(Ops[i-1]); --i) 300c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ++NumAddRecs; 301c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Group Ops into non-addrecs and addrecs. 302c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> NoAddRecs(Ops.begin(), Ops.end() - NumAddRecs); 303c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs(Ops.end() - NumAddRecs, Ops.end()); 304c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Let ScalarEvolution sort and simplify the non-addrecs list. 305c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Sum = NoAddRecs.empty() ? 306deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getConstant(Ty, 0) : 307c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(NoAddRecs); 308c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If it returned an add, use the operands. Otherwise it simplified 309c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the sum into a single value, so just use that. 310f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.clear(); 311c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Sum)) 312403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 313f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman else if (!Sum->isZero()) 314f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.push_back(Sum); 315c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Then append the addrecs. 316403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 317c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 318c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 319c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SplitAddRecs - Flatten a list of add operands, moving addrec start values 320c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// out to the top level. For example, convert {a + b,+,c} to a, b, {0,+,d}. 321c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// This helps expose more opportunities for folding parts of the expressions 322c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// into GEP indices. 323c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 324c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SplitAddRecs(SmallVectorImpl<const SCEV *> &Ops, 325db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 326c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 327c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Find the addrecs. 328c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs; 329c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 330c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) { 331c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Start = A->getStart(); 332c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Start->isZero()) break; 333deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Zero = SE.getConstant(Ty, 0); 334c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AddRecs.push_back(SE.getAddRecExpr(Zero, 335c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getStepRecurrence(SE), 3363228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick A->getLoop(), 3373228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: A->getNoWrapFlags(FlagNW) 3383228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 339c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Start)) { 340c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Zero; 341403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 342c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman e += Add->getNumOperands(); 343c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 344c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Start; 345c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 346c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 347c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!AddRecs.empty()) { 348c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Add the addrecs onto the end of the list. 349403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 350c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Resort the operand list, moving any constants to the front. 351c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 352c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 353c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 354c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 3554c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// expandAddToGEP - Expand an addition expression with a pointer type into 3564c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps 3574c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// BasicAliasAnalysis and other passes analyze the result. See the rules 3584c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for getelementptr vs. inttoptr in 3594c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// http://llvm.org/docs/LangRef.html#pointeraliasing 3604c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for details. 36113c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// 3623abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman/// Design note: The correctness of using getelementptr here depends on 3634c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as 3644c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// they may introduce pointer arithmetic which may not be safely converted 3654c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// into getelementptr. 366453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 367453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Design note: It might seem desirable for this function to be more 368453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-aware. If some of the indices are loop-invariant while others 369453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// aren't, it might seem desirable to emit multiple GEPs, keeping the 370453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of the overall computation outside the loop. 371453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// However, there are a few reasons this is not done here. Hoisting simple 372453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// arithmetic is a low-level optimization that often isn't very 373453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// important until late in the optimization process. In fact, passes 374453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// like InstructionCombining will combine GEPs, even if it means 375453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// pushing loop-invariant computation down into loops, so even if the 376453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEPs were split here, the work would quickly be undone. The 377453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// LoopStrengthReduction pass, which is usually run quite late (and 378453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// after the last InstructionCombining pass), takes care of hoisting 379453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of expressions, after considering what 380453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// can be folded using target addressing modes. 381453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 3820bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin, 3830bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *const *op_end, 384db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner PointerType *PTy, 385db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 3865be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *V) { 387db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ElTy = PTy->getElementType(); 3885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman SmallVector<Value *, 4> GepIndices; 3890bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> Ops(op_begin, op_end); 3905be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman bool AnyNonZeroIndices = false; 3915be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 392c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Split AddRecs up into parts as either of the parts may be usable 393c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // without the other. 394c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SplitAddRecs(Ops, Ty, SE); 395c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 396eb35699e642f2c021f04154bdb4bd90a1afb3baaBob Wilson // Descend down the pointer's type and attempt to convert the other 3975be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // operands into GEP indices, at each level. The first index in a GEP 3985be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // indexes into the array implied by the pointer operand; the rest of 3995be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the indices index into the element or field type selected by the 4005be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // preceding index. 4015be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (;;) { 402c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the scale size is not 0, attempt to factor out a scale for 403c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // array indexing. 4040bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> ScaledOps; 405150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (ElTy->isSized()) { 4064f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const SCEV *ElSize = SE.getSizeOfExpr(ElTy); 407150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ElSize->isZero()) { 408150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SmallVector<const SCEV *, 8> NewOps; 409150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 410150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman const SCEV *Op = Ops[i]; 411deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(Ty, 0); 412150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (FactorOutConstant(Op, Remainder, ElSize, SE, SE.TD)) { 413150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // Op now has ElSize factored out. 414150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman ScaledOps.push_back(Op); 415150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!Remainder->isZero()) 416150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Remainder); 417150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman AnyNonZeroIndices = true; 418150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } else { 419150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // The operand was not divisible, so add it to the list of operands 420150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // we'll scan next iteration. 421150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Ops[i]); 422150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 423150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 424150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // If we made any changes, update Ops. 425150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ScaledOps.empty()) { 426150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman Ops = NewOps; 427150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 4285be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 429c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4305be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 431c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 432c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Record the scaled array index for this level of the type. If 433c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // we didn't find any operands that could be factored, tentatively 434c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // assume that element zero was selected (since the zero offset 435c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // would obviously be folded away). 4365be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *Scaled = ScaledOps.empty() ? 437a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant::getNullValue(Ty) : 4385be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman expandCodeFor(SE.getAddExpr(ScaledOps), Ty); 4395be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman GepIndices.push_back(Scaled); 4405be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4415be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Collect struct field index operands. 442db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner while (StructType *STy = dyn_cast<StructType>(ElTy)) { 443c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman bool FoundFieldNo = false; 444c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // An empty struct has no fields. 445c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (STy->getNumElements() == 0) break; 446c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (SE.TD) { 447c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, field offsets are known. See if a constant offset 448c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // falls within any of the struct fields. 449c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Ops.empty()) break; 4505be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[0])) 4515be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (SE.getTypeSizeInBits(C->getType()) <= 64) { 4525be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const StructLayout &SL = *SE.TD->getStructLayout(STy); 4535be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman uint64_t FullOffset = C->getValue()->getZExtValue(); 4545be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (FullOffset < SL.getSizeInBytes()) { 4555be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(FullOffset); 4561d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson GepIndices.push_back( 4571d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson ConstantInt::get(Type::getInt32Ty(Ty->getContext()), ElIdx)); 4585be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = STy->getTypeAtIndex(ElIdx); 4595be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops[0] = 4606de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman SE.getConstant(Ty, FullOffset - SL.getElementOffset(ElIdx)); 4615be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman AnyNonZeroIndices = true; 462c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 4635be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4645be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 465c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 4660f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman // Without TargetData, just check for an offsetof expression of the 467c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // appropriate struct type. 468c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 4690f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Ops[i])) { 470db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *CTy; 4710f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman Constant *FieldNo; 4724f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (U->isOffsetOf(CTy, FieldNo) && CTy == STy) { 4730f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman GepIndices.push_back(FieldNo); 4740f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman ElTy = 4750f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman STy->getTypeAtIndex(cast<ConstantInt>(FieldNo)->getZExtValue()); 476c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = SE.getConstant(Ty, 0); 477c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AnyNonZeroIndices = true; 478c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 479c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 480c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4810f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman } 4825be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 483c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If no struct field offsets were found, tentatively assume that 484c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // field zero was selected (since the zero offset would obviously 485c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // be folded away). 486c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FoundFieldNo) { 487c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ElTy = STy->getTypeAtIndex(0u); 488c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman GepIndices.push_back( 489c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Constant::getNullValue(Type::getInt32Ty(Ty->getContext()))); 490c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 491c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4925be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 493db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (ArrayType *ATy = dyn_cast<ArrayType>(ElTy)) 4945be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = ATy->getElementType(); 495c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman else 496c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 4975be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4985be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4993f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If none of the operands were convertible to proper GEP indices, cast 5005be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the base to i8* and do an ugly getelementptr with that. It's still 5015be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // better than ptrtoint+arithmetic+inttoptr at least. 5025be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (!AnyNonZeroIndices) { 503c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Cast the base to i8*. 5045be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, 505ac53a0b272452013124bfc70480aea5e41b60f40Duncan Sands Type::getInt8PtrTy(Ty->getContext(), PTy->getAddressSpace())); 506c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 507c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Expand the operands for a plain byte offset. 50892fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *Idx = expandCodeFor(SE.getAddExpr(Ops), Ty); 5095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 5105be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Fold a GEP with constant operands. 5115be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(V)) 5125be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(Idx)) 513dab3d29605a5c83db41b28176273ef55961120c1Jay Foad return ConstantExpr::getGetElementPtr(CLHS, CRHS); 5145be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 5155be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Do a quick scan to see if we have this GEP nearby. If so, reuse it. 5165be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ScanLimit = 6; 517267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 518267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 519267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 520267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 5215be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman --IP; 5225be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (; ScanLimit; --IP, --ScanLimit) { 5238d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 5248d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 5258d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 5268d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 5275be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == Instruction::GetElementPtr && 5285be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(0) == V && IP->getOperand(1) == Idx) 5295be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 5305be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP == BlockBegin) break; 5315be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5325be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5335be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 534087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 535087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 536087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 537087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 538087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 539087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 540087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V) || !L->isLoopInvariant(Idx)) break; 541087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 542087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 543087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 544087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 545087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 546087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 547087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 548c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Emit a GEP. 549c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *GEP = Builder.CreateGEP(V, Idx, "uglygep"); 550a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 551087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 552087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 553087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 554087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 555087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5565be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return GEP; 5575be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5585be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 559087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 560087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 561087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 562087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 563087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 564087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 565087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V)) break; 566087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 567087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool AnyIndexNotLoopInvariant = false; 568087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<Value *>::const_iterator I = GepIndices.begin(), 569087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E = GepIndices.end(); I != E; ++I) 570087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(*I)) { 571087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman AnyIndexNotLoopInvariant = true; 572087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 573087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 574087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (AnyIndexNotLoopInvariant) 575087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 576087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 577087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 578087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 579087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 580087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 581087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 582087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 583087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 584d6aa02de1076c801ac41295156a2379637976918Dan Gohman // Insert a pretty getelementptr. Note that this GEP is not marked inbounds, 585d6aa02de1076c801ac41295156a2379637976918Dan Gohman // because ScalarEvolution may have changed the address arithmetic to 586d6aa02de1076c801ac41295156a2379637976918Dan Gohman // compute a value which is beyond the end of the allocated object. 587a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Casted = V; 588a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (V->getType() != PTy) 589a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Casted = InsertNoopCastOfTo(Casted, PTy); 590a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *GEP = Builder.CreateGEP(Casted, 5910a2a60ace9b79164b71794ce7ff981171c61e442Jay Foad GepIndices, 592267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "scevgep"); 5935be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops.push_back(SE.getUnknown(GEP)); 594a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 595087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 596087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 597087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 598087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 599087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 6005be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return expand(SE.getAddExpr(Ops)); 6015be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman} 6025be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 603087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// PickMostRelevantLoop - Given two loops pick the one that's most relevant for 604087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// SCEV expansion. If they are nested, this is the most nested. If they are 605087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// neighboring, pick the later. 606087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanstatic const Loop *PickMostRelevantLoop(const Loop *A, const Loop *B, 607087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT) { 608087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!A) return B; 609087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!B) return A; 610087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (A->contains(B)) return B; 611087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (B->contains(A)) return A; 612087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(A->getHeader(), B->getHeader())) return B; 613087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(B->getHeader(), A->getHeader())) return A; 614087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return A; // Arbitrarily break the tie. 615087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 616087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 6179c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman/// getRelevantLoop - Get the most relevant loop associated with the given 618087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// expression, according to PickMostRelevantLoop. 6199c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohmanconst Loop *SCEVExpander::getRelevantLoop(const SCEV *S) { 6209c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // Test whether we've already computed the most relevant loop for this SCEV. 6219c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman std::pair<DenseMap<const SCEV *, const Loop *>::iterator, bool> Pair = 6229c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman RelevantLoops.insert(std::make_pair(S, static_cast<const Loop *>(0))); 6239c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (!Pair.second) 6249c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return Pair.first->second; 6259c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman 626087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<SCEVConstant>(S)) 6279c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // A constant has no relevant loops. 628087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 629087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) { 630087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const Instruction *I = dyn_cast<Instruction>(U->getValue())) 6319c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return Pair.first->second = SE.LI->getLoopFor(I->getParent()); 6329c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // A non-instruction has no relevant loops. 633087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 634087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 635087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVNAryExpr *N = dyn_cast<SCEVNAryExpr>(S)) { 636087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *L = 0; 637087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) 638087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman L = AR->getLoop(); 639087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SCEVNAryExpr::op_iterator I = N->op_begin(), E = N->op_end(); 640087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I != E; ++I) 6419c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman L = PickMostRelevantLoop(L, getRelevantLoop(*I), *SE.DT); 6429c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[N] = L; 6439c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman } 6449c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(S)) { 6459c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman const Loop *Result = getRelevantLoop(C->getOperand()); 6469c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[C] = Result; 6479c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman } 6489c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (const SCEVUDivExpr *D = dyn_cast<SCEVUDivExpr>(S)) { 6499c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman const Loop *Result = 6509c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman PickMostRelevantLoop(getRelevantLoop(D->getLHS()), 6519c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman getRelevantLoop(D->getRHS()), 6529c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman *SE.DT); 6539c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[D] = Result; 654087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 655087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman llvm_unreachable("Unexpected SCEV type!"); 656087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 657c4f7ec85ecb760fff2b702c6deb06506b968ba4fDan Gohman 658b35798347ea87b8b6d36155b211016a7769f01abDan Gohmannamespace { 659b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 660087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// LoopCompare - Compare loops by PickMostRelevantLoop. 661087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanclass LoopCompare { 662087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT; 663087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanpublic: 664087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman explicit LoopCompare(DominatorTree &dt) : DT(dt) {} 665087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 666087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool operator()(std::pair<const Loop *, const SCEV *> LHS, 667087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::pair<const Loop *, const SCEV *> RHS) const { 668bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // Keep pointer operands sorted at the end. 669bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (LHS.second->getType()->isPointerTy() != 670bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman RHS.second->getType()->isPointerTy()) 671bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman return LHS.second->getType()->isPointerTy(); 672bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman 673087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Compare loops with PickMostRelevantLoop. 674087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (LHS.first != RHS.first) 675087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return PickMostRelevantLoop(LHS.first, RHS.first, DT) != LHS.first; 676087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 677087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // If one operand is a non-constant negative and the other is not, 678087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // put the non-constant negative on the right so that a sub can 679087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // be used instead of a negate and add. 680f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick if (LHS.second->isNonConstantNegative()) { 681f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick if (!RHS.second->isNonConstantNegative()) 682087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 683f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick } else if (RHS.second->isNonConstantNegative()) 684087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return true; 685087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 686087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Otherwise they are equivalent according to this comparison. 687087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 688c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 689087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman}; 6905be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 691b35798347ea87b8b6d36155b211016a7769f01abDan Gohman} 692b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 693087bd1e3a12893873761736bf0f905a350e9e708Dan GohmanValue *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { 694db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 695e24fa64d52330626553298f56ba5aa702624c282Dan Gohman 696087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the add operands in a loop, along with their associated loops. 697087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal, and 698087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // so that pointer operands are inserted first, which the code below relies on 699087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // to form more involved GEPs. 700087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 701087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVAddExpr::op_iterator> I(S->op_end()), 702087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 7039c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I)); 704087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 705087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants and 706087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // pointer operands precede non-pointer operands. 707087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 708087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 709087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to add all the operands. Hoist as much as possible 710087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops, and form meaningful getelementptrs where possible. 711087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Sum = 0; 712087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 713087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 714087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *CurLoop = I->first; 715087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 716087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Sum) { 717087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 718087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expand(Op); 719087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 720db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner } else if (PointerType *PTy = dyn_cast<PointerType>(Sum->getType())) { 721087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum expression is a pointer. Try to form a getelementptr 722087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // at this level with that as the base. 723087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 724bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman for (; I != E && I->first == CurLoop; ++I) { 725bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // If the operand is SCEVUnknown and not instructions, peek through 726bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // it, to enable more of it to be folded into the GEP. 727bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman const SCEV *X = I->second; 728bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(X)) 729bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (!isa<Instruction>(U->getValue())) 730bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman X = SE.getSCEV(U->getValue()); 731bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman NewOps.push_back(X); 732bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman } 733087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum); 734db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner } else if (PointerType *PTy = dyn_cast<PointerType>(Op->getType())) { 735087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum is an integer, and there's a pointer at this level. 736f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // Try to form a getelementptr. If the running sum is instructions, 737f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // use a SCEVUnknown to avoid re-analyzing them. 738087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 739f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman NewOps.push_back(isa<Instruction>(Sum) ? SE.getUnknown(Sum) : 740f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman SE.getSCEV(Sum)); 741087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (++I; I != E && I->first == CurLoop; ++I) 742087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman NewOps.push_back(I->second); 743087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, expand(Op)); 744f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick } else if (Op->isNonConstantNegative()) { 745087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a negate and add, just do a subtract. 746a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(SE.getNegativeSCEV(Op), Ty); 747087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 748087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Sub, Sum, W); 749087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 750a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 751087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple add. 752a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(Op, Ty); 753087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 754087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 755087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Sum)) std::swap(Sum, W); 756087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Add, Sum, W); 757087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 758a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 7592d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 760087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 761087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Sum; 762e24fa64d52330626553298f56ba5aa702624c282Dan Gohman} 7635be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 764890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) { 765db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 766087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 767087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the mul operands in a loop, along with their associated loops. 768087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal. 769087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 770087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVMulExpr::op_iterator> I(S->op_end()), 771087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 7729c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I)); 773087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 774087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants. 775087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 776087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 777087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to mul all the operands. Hoist as much as possible 778087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops. 779087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Prod = 0; 780087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 781087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 782087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 783087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Prod) { 784087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 785087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = expand(Op); 786087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 787087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (Op->isAllOnesValue()) { 788087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a multiply by negative one, just do a negate. 789087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 790087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Sub, Constant::getNullValue(Ty), Prod); 791087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 792087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else { 793087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple mul. 794087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *W = expandCodeFor(Op, Ty); 795087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 796087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 797087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Prod)) std::swap(Prod, W); 798087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Mul, Prod, W); 799087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 800087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 8012d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 8022d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 803087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Prod; 80436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 80536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 806890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) { 807db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 8082d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 80992fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *LHS = expandCodeFor(S->getLHS(), Ty); 810890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getRHS())) { 8116177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky const APInt &RHS = SC->getValue()->getValue(); 8126177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky if (RHS.isPowerOf2()) 8136177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky return InsertBinop(Instruction::LShr, LHS, 814eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson ConstantInt::get(Ty, RHS.logBase2())); 8156177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky } 8166177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 81792fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getRHS(), Ty); 818267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman return InsertBinop(Instruction::UDiv, LHS, RHS); 8196177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky} 8206177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 821453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Move parts of Base into Rest to leave Base with the minimal 822453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// expression that provides a pointer operand suitable for a 823453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEP expansion. 8240bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic void ExposePointerBase(const SCEV *&Base, const SCEV *&Rest, 825453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ScalarEvolution &SE) { 826453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Base)) { 827453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getStart(); 828453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(Rest, 829deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getAddRecExpr(SE.getConstant(A->getType(), 0), 830453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getStepRecurrence(SE), 8313228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick A->getLoop(), 8323228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: A->getNoWrapFlags(FlagNW) 8333228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 834453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 835453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(Base)) { 836453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getOperand(A->getNumOperands()-1); 8370bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> NewAddOps(A->op_begin(), A->op_end()); 838453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman NewAddOps.back() = Rest; 839453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(NewAddOps); 840453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ExposePointerBase(Base, Rest, SE); 841453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 842453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 843453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 844c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// Determine if this is a well-behaved chain of instructions leading back to 845c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// the PHI. If so, it may be reused by expanded expressions. 846c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trickbool SCEVExpander::isNormalAddRecExprPHI(PHINode *PN, Instruction *IncV, 847c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick const Loop *L) { 848c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getNumOperands() == 0 || isa<PHINode>(IncV) || 849c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick (isa<CastInst>(IncV) && !isa<BitCastInst>(IncV))) 850c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 851c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // If any of the operands don't dominate the insert position, bail. 852c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Addrec operands are always loop-invariant, so this can only happen 853c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // if there are instructions which haven't been hoisted. 854c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (L == IVIncInsertLoop) { 855c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (User::op_iterator OI = IncV->op_begin()+1, 856c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick OE = IncV->op_end(); OI != OE; ++OI) 857c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (Instruction *OInst = dyn_cast<Instruction>(OI)) 858c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!SE.DT->dominates(OInst, IVIncInsertPos)) 859c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 860c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 861c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Advance to the next instruction. 862c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 863c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!IncV) 864c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 865c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 866c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->mayHaveSideEffects()) 867c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 868c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 869c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV != PN) 870c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return true; 871c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 872c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return isNormalAddRecExprPHI(PN, IncV, L); 873c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick} 874c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 875b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// getIVIncOperand returns an induction variable increment's induction 876b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// variable operand. 877b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// 878b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// If allowScale is set, any type of GEP is allowed as long as the nonIV 879b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// operands dominate InsertPos. 880b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// 881b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// If allowScale is not set, ensure that a GEP increment conforms to one of the 882b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// simple patterns generated by getAddRecExprPHILiterally and 883b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// expandAddtoGEP. If the pattern isn't recognized, return NULL. 884b5c26ef9da16052597d59a412eaae32098aa1be0Andrew TrickInstruction *SCEVExpander::getIVIncOperand(Instruction *IncV, 885b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick Instruction *InsertPos, 886b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick bool allowScale) { 887b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (IncV == InsertPos) 888b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 88964925c55c65f9345a69fb67db07aa62cfb723577Andrew Trick 890c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick switch (IncV->getOpcode()) { 891b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick default: 892b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 893c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Check for a simple Add/Sub or GEP of a loop invariant step. 894c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::Add: 895b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick case Instruction::Sub: { 896b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick Instruction *OInst = dyn_cast<Instruction>(IncV->getOperand(1)); 897b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (!OInst || SE.DT->properlyDominates(OInst, InsertPos)) 898b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return dyn_cast<Instruction>(IncV->getOperand(0)); 899b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 900b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 901c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::BitCast: 902b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return dyn_cast<Instruction>(IncV->getOperand(0)); 903b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick case Instruction::GetElementPtr: 904c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (Instruction::op_iterator I = IncV->op_begin()+1, E = IncV->op_end(); 905c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick I != E; ++I) { 906c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (isa<Constant>(*I)) 907c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 908b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (Instruction *OInst = dyn_cast<Instruction>(*I)) { 909b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (!SE.DT->properlyDominates(OInst, InsertPos)) 910b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 911b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 912b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (allowScale) { 913b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // allow any kind of GEP as long as it can be hoisted. 914b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick continue; 915b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 916b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // This must be a pointer addition of constants (pretty), which is already 917b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // handled, or some number of address-size elements (ugly). Ugly geps 918b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // have 2 operands. i1* is used by the expander to represent an 919b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // address-size element. 920c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getNumOperands() != 2) 921b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 922365c9f1ff55bef134c6b9707f7df44d680ddabeaAndrew Trick unsigned AS = cast<PointerType>(IncV->getType())->getAddressSpace(); 923c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getType() != Type::getInt1PtrTy(SE.getContext(), AS) 924c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick && IncV->getType() != Type::getInt8PtrTy(SE.getContext(), AS)) 925b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 926c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick break; 927c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 928b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return dyn_cast<Instruction>(IncV->getOperand(0)); 929c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 930b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick} 931b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick 932b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// hoistStep - Attempt to hoist a simple IV increment above InsertPos to make 933b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// it available to other uses in this loop. Recursively hoist any operands, 934b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// until we reach a value that dominates InsertPos. 935b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trickbool SCEVExpander::hoistIVInc(Instruction *IncV, Instruction *InsertPos) { 936b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (SE.DT->properlyDominates(IncV, InsertPos)) 937b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return true; 938b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick 939b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // InsertPos must itself dominate IncV so that IncV's new position satisfies 940b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // its existing users. 941b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (!SE.DT->dominates(InsertPos->getParent(), IncV->getParent())) 942c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 943b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick 944b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // Check that the chain of IV operands leading back to Phi can be hoisted. 945b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick SmallVector<Instruction*, 4> IVIncs; 946b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick for(;;) { 947b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick Instruction *Oper = getIVIncOperand(IncV, InsertPos, /*allowScale*/true); 948b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (!Oper) 949b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return false; 950b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // IncV is safe to hoist. 951b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick IVIncs.push_back(IncV); 952b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick IncV = Oper; 953b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (SE.DT->properlyDominates(IncV, InsertPos)) 954b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick break; 955b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 956b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick for (SmallVectorImpl<Instruction*>::reverse_iterator I = IVIncs.rbegin(), 957b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick E = IVIncs.rend(); I != E; ++I) { 958b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick (*I)->moveBefore(InsertPos); 959b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 960b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return true; 961b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick} 962b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick 963b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// Determine if this cyclic phi is in a form that would have been generated by 964b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// LSR. We don't care if the phi was actually expanded in this pass, as long 965b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// as it is in a low-cost form, for example, no implied multiplication. This 966b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// should match any patterns generated by getAddRecExprPHILiterally and 967b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// expandAddtoGEP. 968b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trickbool SCEVExpander::isExpandedAddRecExprPHI(PHINode *PN, Instruction *IncV, 969b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick const Loop *L) { 970b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick for(Instruction *IVOper = IncV; 971b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick (IVOper = getIVIncOperand(IVOper, L->getLoopPreheader()->getTerminator(), 972b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick /*allowScale=*/false));) { 973b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (IVOper == PN) 974b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return true; 975c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 976b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return false; 977c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick} 978c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 979553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick/// expandIVInc - Expand an IV increment at Builder's current InsertPos. 980553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick/// Typically this is the LatchBlock terminator or IVIncInsertPos, but we may 981553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick/// need to materialize IV increments elsewhere to handle difficult situations. 982553fe05f236f46fe27b7fcfa822b06367d50183eAndrew TrickValue *SCEVExpander::expandIVInc(PHINode *PN, Value *StepV, const Loop *L, 983553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Type *ExpandTy, Type *IntTy, 984553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick bool useSubtract) { 985553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Value *IncV; 986553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If the PHI is a pointer, use a GEP, otherwise use an add or sub. 987553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (ExpandTy->isPointerTy()) { 988553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick PointerType *GEPPtrTy = cast<PointerType>(ExpandTy); 989553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If the step isn't constant, don't use an implicitly scaled GEP, because 990553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // that would require a multiply inside the loop. 991553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (!isa<ConstantInt>(StepV)) 992553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick GEPPtrTy = PointerType::get(Type::getInt1Ty(SE.getContext()), 993553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick GEPPtrTy->getAddressSpace()); 994553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick const SCEV *const StepArray[1] = { SE.getSCEV(StepV) }; 995553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick IncV = expandAddToGEP(StepArray, StepArray+1, GEPPtrTy, IntTy, PN); 996553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (IncV->getType() != PN->getType()) { 997553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick IncV = Builder.CreateBitCast(IncV, PN->getType()); 998553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick rememberInstruction(IncV); 999553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } 1000553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } else { 1001553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick IncV = useSubtract ? 1002553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Builder.CreateSub(PN, StepV, Twine(IVName) + ".iv.next") : 1003553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Builder.CreateAdd(PN, StepV, Twine(IVName) + ".iv.next"); 1004553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick rememberInstruction(IncV); 1005553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } 1006553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick return IncV; 1007553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick} 1008553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick 1009a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// getAddRecExprPHILiterally - Helper for expandAddRecExprLiterally. Expand 1010a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// the base addrec, which is the addrec without any non-loop-dominating 1011a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// values, and return the PHI. 1012a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanPHINode * 1013a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanSCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized, 1014a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L, 1015db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ExpandTy, 1016db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntTy) { 101793a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer assert((!IVIncInsertLoop||IVIncInsertPos) && "Uninitialized insert position"); 1018d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 1019a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Reuse a previously-inserted PHI, if present. 1020c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick BasicBlock *LatchBlock = L->getLoopLatch(); 1021c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (LatchBlock) { 1022c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (BasicBlock::iterator I = L->getHeader()->begin(); 1023c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick PHINode *PN = dyn_cast<PHINode>(I); ++I) { 1024c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!SE.isSCEVable(PN->getType()) || 1025c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick (SE.getEffectiveSCEVType(PN->getType()) != 1026c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick SE.getEffectiveSCEVType(Normalized->getType())) || 1027c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick SE.getSCEV(PN) != Normalized) 1028c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 1029c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 1030c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick Instruction *IncV = 1031c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)); 1032c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 1033c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (LSRMode) { 1034365c9f1ff55bef134c6b9707f7df44d680ddabeaAndrew Trick if (!isExpandedAddRecExprPHI(PN, IncV, L)) 1035c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 1036b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (L == IVIncInsertLoop && !hoistIVInc(IncV, IVIncInsertPos)) 1037b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick continue; 1038c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 1039c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick else { 1040c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!isNormalAddRecExprPHI(PN, IncV, L)) 1041c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 1042b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (L == IVIncInsertLoop) 1043b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick do { 1044b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (SE.DT->dominates(IncV, IVIncInsertPos)) 1045b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick break; 1046b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // Make sure the increment is where we want it. But don't move it 1047b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // down past a potential existing post-inc user. 1048b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick IncV->moveBefore(IVIncInsertPos); 1049b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick IVIncInsertPos = IncV; 1050b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick IncV = cast<Instruction>(IncV->getOperand(0)); 1051b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } while (IncV != PN); 1052c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 1053c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Ok, the add recurrence looks usable. 1054c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Remember this PHI, even in post-inc mode. 1055c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick InsertedValues.insert(PN); 1056c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Remember the increment. 1057c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick rememberInstruction(IncV); 1058c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return PN; 1059c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 1060c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 1061a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1062a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Save the original insertion point so we can restore it when we're done. 1063a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1064a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1065a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1066ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // Another AddRec may need to be recursively expanded below. For example, if 1067ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // this AddRec is quadratic, the StepV may itself be an AddRec in this 1068ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // loop. Remove this loop from the PostIncLoops set before expanding such 1069ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // AddRecs. Otherwise, we cannot find a valid position for the step 1070ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // (i.e. StepV can never dominate its loop header). Ideally, we could do 1071ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // SavedIncLoops.swap(PostIncLoops), but we generally have a single element, 1072ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // so it's not worth implementing SmallPtrSet::swap. 1073ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick PostIncLoopSet SavedPostIncLoops = PostIncLoops; 1074ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick PostIncLoops.clear(); 1075ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick 1076a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the start value. 1077a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StartV = expandCodeFor(Normalized->getStart(), ExpandTy, 1078a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman L->getHeader()->begin()); 1079a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1080d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick // StartV must be hoisted into L's preheader to dominate the new phi. 108193a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer assert(!isa<Instruction>(StartV) || 108293a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer SE.DT->properlyDominates(cast<Instruction>(StartV)->getParent(), 108393a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer L->getHeader())); 1084d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 1085553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Expand code for the step value. Do this before creating the PHI so that PHI 1086553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // reuse code doesn't see an incomplete PHI. 1087a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 1088553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If the stride is negative, insert a sub instead of an add for the increment 1089553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // (unless it's a constant, because subtracts of constants are canonicalized 1090553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // to adds). 1091f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick bool useSubtract = !ExpandTy->isPointerTy() && Step->isNonConstantNegative(); 1092553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (useSubtract) 1093a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Step = SE.getNegativeSCEV(Step); 1094553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Expand the step somewhere that dominates the loop header. 1095a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StepV = expandCodeFor(Step, IntTy, L->getHeader()->begin()); 1096a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1097a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the PHI. 1098d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad BasicBlock *Header = L->getHeader(); 1099d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad Builder.SetInsertPoint(Header, Header->begin()); 1100d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad pred_iterator HPB = pred_begin(Header), HPE = pred_end(Header); 11015e7645be4c9dd2193add44d30b5fef8036d7a3ceAndrew Trick PHINode *PN = Builder.CreatePHI(ExpandTy, std::distance(HPB, HPE), 1102dc8e546048db2f7ff5656742b2b26975098a11a0Andrew Trick Twine(IVName) + ".iv"); 1103a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(PN); 1104a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1105a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the step instructions and populate the PHI. 1106d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad for (pred_iterator HPI = HPB; HPI != HPE; ++HPI) { 1107a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *Pred = *HPI; 1108a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1109a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Add a start value. 1110a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!L->contains(Pred)) { 1111a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(StartV, Pred); 1112a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman continue; 1113a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1114a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1115553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Create a step value and add it to the PHI. 1116553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If IVIncInsertLoop is non-null and equal to the addrec's loop, insert the 1117553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // instructions at IVIncInsertPos. 1118a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Instruction *InsertPos = L == IVIncInsertLoop ? 1119a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IVIncInsertPos : Pred->getTerminator(); 1120c5ecbdc1896f1cc089372feef3191ace2f840898Devang Patel Builder.SetInsertPoint(InsertPos); 1121553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Value *IncV = expandIVInc(PN, StepV, L, ExpandTy, IntTy, useSubtract); 1122553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick 1123a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(IncV, Pred); 1124a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1125a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1126a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Restore the original insert point. 1127a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (SaveInsertBB) 1128455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1129a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1130ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // After expanding subexpressions, restore the PostIncLoops set so the caller 1131ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // can ensure that IVIncrement dominates the current uses. 1132ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick PostIncLoops = SavedPostIncLoops; 1133ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick 1134a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Remember this PHI, even in post-inc mode. 1135a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman InsertedValues.insert(PN); 1136a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1137a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return PN; 1138a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1139a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1140a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanValue *SCEVExpander::expandAddRecExprLiterally(const SCEVAddRecExpr *S) { 1141db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *STy = S->getType(); 1142db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntTy = SE.getEffectiveSCEVType(STy); 1143a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L = S->getLoop(); 1144a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1145a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Determine a normalized form of this expression, which is the expression 1146a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // before any post-inc adjustment is made. 1147a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVAddRecExpr *Normalized = S; 1148448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (PostIncLoops.count(L)) { 1149448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman PostIncLoopSet Loops; 1150448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops.insert(L); 1151448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Normalized = 1152448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman cast<SCEVAddRecExpr>(TransformForPostIncUse(Normalize, S, 0, 0, 1153448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops, SE, *SE.DT)); 1154a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1155a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1156a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec start. 1157a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Start = Normalized->getStart(); 1158a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopOffset = 0; 1159dc0e8fb9f9512622f55f73e1a434caa5c0915694Dan Gohman if (!SE.properlyDominates(Start, L->getHeader())) { 1160a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopOffset = Start; 1161deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Start = SE.getConstant(Normalized->getType(), 0); 11623228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized = cast<SCEVAddRecExpr>( 11633228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SE.getAddRecExpr(Start, Normalized->getStepRecurrence(SE), 11643228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized->getLoop(), 11653228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: Normalized->getNoWrapFlags(FlagNW) 11663228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1167a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1168a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1169a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec step. 1170a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 1171a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopScale = 0; 1172dc0e8fb9f9512622f55f73e1a434caa5c0915694Dan Gohman if (!SE.dominates(Step, L->getHeader())) { 1173a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopScale = Step; 1174deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Step = SE.getConstant(Normalized->getType(), 1); 1175a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized = 1176a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start, Step, 11773228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized->getLoop(), 11783228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: Normalized 11793228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // ->getNoWrapFlags(FlagNW) 11803228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1181a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1182a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1183a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand the core addrec. If we need post-loop scaling, force it to 1184a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // expand to an integer type to avoid the need for additional casting. 1185db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ExpandTy = PostLoopScale ? IntTy : STy; 1186a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = getAddRecExprPHILiterally(Normalized, L, ExpandTy, IntTy); 1187a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 11883f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // Accommodate post-inc mode, if necessary. 1189a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Result; 1190448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (!PostIncLoops.count(L)) 1191a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN; 1192a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman else { 1193a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // In PostInc mode, use the post-incremented value. 1194a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *LatchBlock = L->getLoopLatch(); 1195a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman assert(LatchBlock && "PostInc mode requires a unique loop latch!"); 1196a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN->getIncomingValueForBlock(LatchBlock); 119748ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick 119848ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // For an expansion to use the postinc form, the client must call 119948ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // expandCodeFor with an InsertPoint that is either outside the PostIncLoop 120048ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // or dominated by IVIncInsertPos. 1201553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (isa<Instruction>(Result) 1202553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick && !SE.DT->dominates(cast<Instruction>(Result), 1203553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Builder.GetInsertPoint())) { 1204553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // The induction variable's postinc expansion does not dominate this use. 1205553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // IVUsers tries to prevent this case, so it is rare. However, it can 1206553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // happen when an IVUser outside the loop is not dominated by the latch 1207553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // block. Adjusting IVIncInsertPos before expansion begins cannot handle 1208553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // all cases. Consider a phi outide whose operand is replaced during 1209553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // expansion with the value of the postinc user. Without fundamentally 1210553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // changing the way postinc users are tracked, the only remedy is 1211553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // inserting an extra IV increment. StepV might fold into PostLoopOffset, 1212553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // but hopefully expandCodeFor handles that. 1213553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick bool useSubtract = 1214f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick !ExpandTy->isPointerTy() && Step->isNonConstantNegative(); 1215553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (useSubtract) 1216553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Step = SE.getNegativeSCEV(Step); 1217553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Expand the step somewhere that dominates the loop header. 1218553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1219553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1220553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Value *StepV = expandCodeFor(Step, IntTy, L->getHeader()->begin()); 1221553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Restore the insertion point to the place where the caller has 1222553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // determined dominates all uses. 1223553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1224553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Result = expandIVInc(PN, StepV, L, ExpandTy, IntTy, useSubtract); 1225553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } 1226a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1227a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1228a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating scale. 1229a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopScale) { 12300a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1231a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateMul(Result, 1232a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopScale, IntTy)); 1233a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1234a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1235a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1236a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating offset. 1237a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopOffset) { 1238db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (PointerType *PTy = dyn_cast<PointerType>(ExpandTy)) { 1239a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const OffsetArray[1] = { PostLoopOffset }; 1240a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = expandAddToGEP(OffsetArray, OffsetArray+1, PTy, IntTy, Result); 1241a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 12420a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1243a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateAdd(Result, 1244a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopOffset, IntTy)); 1245a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1246a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1247a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1248a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1249a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return Result; 1250a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1251a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1252890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { 1253a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!CanonicalMode) return expandAddRecExprLiterally(S); 1254a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1255db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 125636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Loop *L = S->getLoop(); 125736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12584d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // First check for an existing canonical IV in a suitable type. 12594d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman PHINode *CanonicalIV = 0; 12604d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (PHINode *PN = L->getCanonicalInductionVariable()) 1261133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman if (SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty)) 12624d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV = PN; 12634d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 12644d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Rewrite an AddRec in terms of the canonical induction variable, if 12654d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // its type is more narrow. 12664d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (CanonicalIV && 12674d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(CanonicalIV->getType()) > 12684d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(Ty)) { 1269f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->getNumOperands()); 1270f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman for (unsigned i = 0, e = S->getNumOperands(); i != e; ++i) 1271f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman NewOps[i] = SE.getAnyExtendExpr(S->op_begin()[i], CanonicalIV->getType()); 12723228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Value *V = expand(SE.getAddRecExpr(NewOps, S->getLoop(), 12733228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: S->getNoWrapFlags(FlagNW) 12743228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1275267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1276267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 12774d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman BasicBlock::iterator NewInsertPt = 12787896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner llvm::next(BasicBlock::iterator(cast<Instruction>(V))); 1279a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling while (isa<PHINode>(NewInsertPt) || isa<DbgInfoIntrinsic>(NewInsertPt) || 1280a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(NewInsertPt)) 128108f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach ++NewInsertPt; 12824d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), 0, 12834d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewInsertPt); 1284455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 12854d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman return V; 12864d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman } 12874d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 128836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {X,+,F} --> X + {0,+,F} 1289cfeb6a450632f2a6cd05302633c8c2b8c90cfdfdDan Gohman if (!S->getStart()->isZero()) { 1290f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->op_begin(), S->op_end()); 1291deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman NewOps[0] = SE.getConstant(Ty, 0); 12923228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: can use S->getNoWrapFlags() 12933228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick const SCEV *Rest = SE.getAddRecExpr(NewOps, L, SCEV::FlagAnyWrap); 1294453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 1295453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the 1296453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // comments on expandAddToGEP for details. 1297c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Base = S->getStart(); 1298c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *RestArray[1] = { Rest }; 1299c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Dig into the expression to find the pointer base for a GEP. 1300c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ExposePointerBase(Base, RestArray[0], SE); 1301c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If we found a pointer, expand the AddRec with a GEP. 1302db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (PointerType *PTy = dyn_cast<PointerType>(Base->getType())) { 1303c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Make sure the Base isn't something exotic, such as a multiplied 1304c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // or divided pointer value. In those cases, the result type isn't 1305c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // actually a pointer type. 1306c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!isa<SCEVMulExpr>(Base) && !isa<SCEVUDivExpr>(Base)) { 1307c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *StartV = expand(Base); 1308c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman assert(StartV->getType() == PTy && "Pointer type mismatch for GEP!"); 1309c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return expandAddToGEP(RestArray, RestArray+1, PTy, Ty, StartV); 1310453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1311453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1312453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 131340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Just do a normal add. Pre-expand the operands to suppress folding. 131440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return expand(SE.getAddExpr(SE.getUnknown(expand(S->getStart())), 131540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getUnknown(expand(Rest)))); 131636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 131736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13186ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // If we don't yet have a canonical IV, create one. 13196ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (!CanonicalIV) { 132036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Create and insert the PHI node for the induction variable in the 132136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // specified loop. 132236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman BasicBlock *Header = L->getHeader(); 1323d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad pred_iterator HPB = pred_begin(Header), HPE = pred_end(Header); 13243ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad CanonicalIV = PHINode::Create(Ty, std::distance(HPB, HPE), "indvar", 13253ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad Header->begin()); 13266ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman rememberInstruction(CanonicalIV); 132736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1328eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Constant *One = ConstantInt::get(Ty, 1); 1329d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad for (pred_iterator HPI = HPB; HPI != HPE; ++HPI) { 13307656018c2268285907cfdc106071462a01a73878Gabor Greif BasicBlock *HP = *HPI; 13317656018c2268285907cfdc106071462a01a73878Gabor Greif if (L->contains(HP)) { 13323abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // Insert a unit add instruction right before the terminator 13333abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // corresponding to the back-edge. 13346ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman Instruction *Add = BinaryOperator::CreateAdd(CanonicalIV, One, 13356ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "indvar.next", 13366ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman HP->getTerminator()); 1337df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel Add->setDebugLoc(HP->getTerminator()->getDebugLoc()); 1338a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Add); 13396ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Add, HP); 134083d577490b1473213b6973236110c28e59127956Dan Gohman } else { 13416ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Constant::getNullValue(Ty), HP); 134283d577490b1473213b6973236110c28e59127956Dan Gohman } 13437656018c2268285907cfdc106071462a01a73878Gabor Greif } 134436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 134536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13466ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // {0,+,1} --> Insert a canonical induction variable into the loop! 13476ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (S->isAffine() && S->getOperand(1)->isOne()) { 13486ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) && 13496ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "IVs with types different from the canonical IV should " 13506ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "already have been handled!"); 13516ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman return CanonicalIV; 13526ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman } 13536ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman 13544d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // {0,+,F} --> {0,+,1} * F 135536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1356df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If this is a simple linear addrec, emit it now as a special case. 135740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (S->isAffine()) // {0,+,F} --> i*F 135840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return 135940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman expand(SE.getTruncateOrNoop( 13606ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman SE.getMulExpr(SE.getUnknown(CanonicalIV), 136140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getNoopOrAnyExtend(S->getOperand(1), 13626ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->getType())), 136340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Ty)); 136436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 136536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // If this is a chain of recurrences, turn it into a closed form, using the 136636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // folders, then expandCodeFor the closed form. This allows the folders to 136736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // simplify the expression without having to build a bunch of special code 136836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // into this folder. 13696ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *IH = SE.getUnknown(CanonicalIV); // Get I as a "symbolic" SCEV. 137036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13714d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Promote S up to the canonical IV type, if the cast is foldable. 13720bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *NewS = S; 13736ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *Ext = SE.getNoopOrAnyExtend(S, CanonicalIV->getType()); 13744d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (isa<SCEVAddRecExpr>(Ext)) 13754d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewS = Ext; 13764d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 13770bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE); 1378e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; 137936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13804d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Truncate the result down to the original type, if needed. 13810bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *T = SE.getTruncateOrNoop(V, Ty); 1382469f3cdc13851914f3a766cbd8f701cf8431cacaDan Gohman return expand(T); 138336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 138496fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 1385890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitTruncateExpr(const SCEVTruncateExpr *S) { 1386db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 138792fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 138892fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1389a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateTrunc(V, Ty); 1390a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1391cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 139211f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 139311f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1394890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitZeroExtendExpr(const SCEVZeroExtendExpr *S) { 1395db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 139692fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 139792fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1398a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateZExt(V, Ty); 1399a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1400cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 140111f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 140211f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1403890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) { 1404db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 140592fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 140692fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1407a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateSExt(V, Ty); 1408a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1409cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 141011f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 141111f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1412890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { 14130196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 1414db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = LHS->getType(); 14150196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 14160196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 14170196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 14180196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 14190196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 14200196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 14210196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 142292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1423a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *ICmp = Builder.CreateICmpSGT(LHS, RHS); 1424a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1425267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "smax"); 1426a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1427cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 1428c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky } 14290196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 14300196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 14310196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 14320196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 1433c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky return LHS; 1434c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky} 1435c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky 1436890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { 14370196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 1438db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = LHS->getType(); 14390196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 14400196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 14410196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 14420196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 14430196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 14440196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 14450196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 144692fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1447a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *ICmp = Builder.CreateICmpUGT(LHS, RHS); 1448a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1449267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "umax"); 1450a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1451cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 14523e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky } 14530196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 14540196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 14550196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 14560196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 14573e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky return LHS; 14583e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky} 14593e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky 1460db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::expandCodeFor(const SCEV *SH, Type *Ty, 1461b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick Instruction *IP) { 14626c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Builder.SetInsertPoint(IP->getParent(), IP); 14636c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman return expandCodeFor(SH, Ty); 14646c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman} 14656c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman 1466db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::expandCodeFor(const SCEV *SH, Type *Ty) { 146711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman // Expand the code for this SCEV. 14682d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *V = expand(SH); 14695be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Ty) { 14705be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman assert(SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(SH->getType()) && 14715be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman "non-trivial casts should be done with the SCEVs directly!"); 14725be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, Ty); 14735be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 14745be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return V; 147511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 147611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1477890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::expand(const SCEV *S) { 147840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Compute an insertion point for this SCEV object. Hoist the instructions 147940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // as far out in the loop nest as possible. 1480267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *InsertPt = Builder.GetInsertPoint(); 1481267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman for (Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock()); ; 148240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman L = L->getParentLoop()) 148317ead4ff4baceb2c5503f233d0288d363ae44165Dan Gohman if (SE.isLoopInvariant(S, L)) { 148440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (!L) break; 1485e059ee832ca36d65a5fb87b0ac5bcdb0490b15cbDan Gohman if (BasicBlock *Preheader = L->getLoopPreheader()) 148640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = Preheader->getTerminator(); 14870f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick else { 14880f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick // LSR sets the insertion point for AddRec start/step values to the 14890f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick // block start to simplify value reuse, even though it's an invalid 14900f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick // position. SCEVExpander must correct for this in all cases. 14910f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick InsertPt = L->getHeader()->getFirstInsertionPt(); 14920f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick } 149340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } else { 149440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // If the SCEV is computable at this level, insert it into the header 149540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // after the PHIs (and after any other instructions that we've inserted 149640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // there) so that it is guaranteed to dominate any user inside the loop. 14975b6f42f57e730c2d968c313a27fa505a3c3e5efaBill Wendling if (L && SE.hasComputableLoopEvolution(S, L) && !PostIncLoops.count(L)) 14985b6f42f57e730c2d968c313a27fa505a3c3e5efaBill Wendling InsertPt = L->getHeader()->getFirstInsertionPt(); 1499b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick while (InsertPt != Builder.GetInsertPoint() 1500b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick && (isInsertedInstruction(InsertPt) 1501b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick || isa<DbgInfoIntrinsic>(InsertPt))) { 15027896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner InsertPt = llvm::next(BasicBlock::iterator(InsertPt)); 1503b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 150440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman break; 150540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } 150640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1507667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Check to see if we already expanded this here. 1508667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman std::map<std::pair<const SCEV *, Instruction *>, 1509667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman AssertingVH<Value> >::iterator I = 1510667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman InsertedExpressions.find(std::make_pair(S, InsertPt)); 1511267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (I != InsertedExpressions.end()) 1512667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman return I->second; 1513267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 1514267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1515267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1516267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(InsertPt->getParent(), InsertPt); 1517667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1518667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Expand the expression into instructions. 151996fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov Value *V = visit(S); 152040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1521667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Remember the expanded value for this SCEV at this location. 152248ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // 152348ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // This is independent of PostIncLoops. The mapped value simply materializes 152448ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // the expression at this insertion point. If the mapped value happened to be 152548ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // a postinc expansion, it could be reused by a non postinc user, but only if 152648ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // its insertion point was already at the head of the loop. 152748ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick InsertedExpressions[std::make_pair(S, InsertPt)] = V; 1528667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1529455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 153096fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return V; 153196fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov} 15321d09de3eca23267855e28297fcb40de3632ea47bDan Gohman 15331d826a76f591afea445489b9a5485c345e66bf87Dan Gohmanvoid SCEVExpander::rememberInstruction(Value *I) { 153425fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman if (!PostIncLoops.empty()) 153525fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman InsertedPostIncValues.insert(I); 153625fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman else 15371d826a76f591afea445489b9a5485c345e66bf87Dan Gohman InsertedValues.insert(I); 15381d826a76f591afea445489b9a5485c345e66bf87Dan Gohman} 15391d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 1540455985501381777db03534c925a35e261e356395Dan Gohmanvoid SCEVExpander::restoreInsertPoint(BasicBlock *BB, BasicBlock::iterator I) { 1541455985501381777db03534c925a35e261e356395Dan Gohman Builder.SetInsertPoint(BB, I); 1542455985501381777db03534c925a35e261e356395Dan Gohman} 1543455985501381777db03534c925a35e261e356395Dan Gohman 15441d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// getOrInsertCanonicalInductionVariable - This method returns the 15451d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// canonical induction variable of the specified type for the specified 15461d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// loop (inserting one if there is none). A canonical induction variable 15471d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// starts at zero and steps by one on each iteration. 15487c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan GohmanPHINode * 15491d09de3eca23267855e28297fcb40de3632ea47bDan GohmanSCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L, 1550db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty) { 1551b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands assert(Ty->isIntegerTy() && "Can only insert integer induction variables!"); 1552133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1553133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Build a SCEV for {0,+,1}<L>. 15543228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // Conservatively use FlagAnyWrap for now. 1555deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *H = SE.getAddRecExpr(SE.getConstant(Ty, 0), 15563228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SE.getConstant(Ty, 1), L, SCEV::FlagAnyWrap); 1557133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1558133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Emit code for it. 1559267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1560267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 15617c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan Gohman PHINode *V = cast<PHINode>(expandCodeFor(H, 0, L->getHeader()->begin())); 1562267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (SaveInsertBB) 1563455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1564133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 156540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return V; 15661d09de3eca23267855e28297fcb40de3632ea47bDan Gohman} 1567204494149b6f846e8f173f525b129f5508076049Andrew Trick 1568139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trick/// Sort values by integer width for replaceCongruentIVs. 1569139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trickstatic bool width_descending(Value *lhs, Value *rhs) { 1570ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Put pointers at the back and make sure pointer < pointer = false. 1571ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (!lhs->getType()->isIntegerTy() || !rhs->getType()->isIntegerTy()) 1572ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick return rhs->getType()->isIntegerTy() && !lhs->getType()->isIntegerTy(); 1573ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick return rhs->getType()->getPrimitiveSizeInBits() 1574ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick < lhs->getType()->getPrimitiveSizeInBits(); 1575ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick} 1576ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick 1577204494149b6f846e8f173f525b129f5508076049Andrew Trick/// replaceCongruentIVs - Check for congruent phis in this loop header and 1578204494149b6f846e8f173f525b129f5508076049Andrew Trick/// replace them with their most canonical representative. Return the number of 1579204494149b6f846e8f173f525b129f5508076049Andrew Trick/// phis eliminated. 1580204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1581204494149b6f846e8f173f525b129f5508076049Andrew Trick/// This does not depend on any SCEVExpander state but should be used in 1582204494149b6f846e8f173f525b129f5508076049Andrew Trick/// the same context that SCEVExpander is used. 1583204494149b6f846e8f173f525b129f5508076049Andrew Trickunsigned SCEVExpander::replaceCongruentIVs(Loop *L, const DominatorTree *DT, 1584ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick SmallVectorImpl<WeakVH> &DeadInsts, 1585ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick const TargetLowering *TLI) { 1586ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Find integer phis in order of increasing width. 1587ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick SmallVector<PHINode*, 8> Phis; 1588ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick for (BasicBlock::iterator I = L->getHeader()->begin(); 1589ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick PHINode *Phi = dyn_cast<PHINode>(I); ++I) { 1590ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Phis.push_back(Phi); 1591ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1592ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (TLI) 1593ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick std::sort(Phis.begin(), Phis.end(), width_descending); 1594ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick 1595204494149b6f846e8f173f525b129f5508076049Andrew Trick unsigned NumElim = 0; 1596204494149b6f846e8f173f525b129f5508076049Andrew Trick DenseMap<const SCEV *, PHINode *> ExprToIVMap; 1597ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Process phis from wide to narrow. Mapping wide phis to the their truncation 1598ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // so narrow phis can reuse them. 1599ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick for (SmallVectorImpl<PHINode*>::const_iterator PIter = Phis.begin(), 1600ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick PEnd = Phis.end(); PIter != PEnd; ++PIter) { 1601ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick PHINode *Phi = *PIter; 1602ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick 1603204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!SE.isSCEVable(Phi->getType())) 1604204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1605204494149b6f846e8f173f525b129f5508076049Andrew Trick 1606204494149b6f846e8f173f525b129f5508076049Andrew Trick PHINode *&OrigPhiRef = ExprToIVMap[SE.getSCEV(Phi)]; 1607204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!OrigPhiRef) { 1608204494149b6f846e8f173f525b129f5508076049Andrew Trick OrigPhiRef = Phi; 1609ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (Phi->getType()->isIntegerTy() && TLI 1610ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick && TLI->isTruncateFree(Phi->getType(), Phis.back()->getType())) { 1611ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // This phi can be freely truncated to the narrowest phi type. Map the 1612ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // truncated expression to it so it will be reused for narrow types. 1613ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick const SCEV *TruncExpr = 1614ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick SE.getTruncateExpr(SE.getSCEV(Phi), Phis.back()->getType()); 1615ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick ExprToIVMap[TruncExpr] = Phi; 1616ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1617204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1618204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1619204494149b6f846e8f173f525b129f5508076049Andrew Trick 1620ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Replacing a pointer phi with an integer phi or vice-versa doesn't make 1621ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // sense. 1622ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigPhiRef->getType()->isPointerTy() != Phi->getType()->isPointerTy()) 1623204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1624204494149b6f846e8f173f525b129f5508076049Andrew Trick 1625204494149b6f846e8f173f525b129f5508076049Andrew Trick if (BasicBlock *LatchBlock = L->getLoopLatch()) { 1626204494149b6f846e8f173f525b129f5508076049Andrew Trick Instruction *OrigInc = 1627204494149b6f846e8f173f525b129f5508076049Andrew Trick cast<Instruction>(OrigPhiRef->getIncomingValueForBlock(LatchBlock)); 1628204494149b6f846e8f173f525b129f5508076049Andrew Trick Instruction *IsomorphicInc = 1629204494149b6f846e8f173f525b129f5508076049Andrew Trick cast<Instruction>(Phi->getIncomingValueForBlock(LatchBlock)); 1630204494149b6f846e8f173f525b129f5508076049Andrew Trick 1631ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // If this phi has the same width but is more canonical, replace the 1632b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // original with it. As part of the "more canonical" determination, 1633b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // respect a prior decision to use an IV chain. 1634ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigPhiRef->getType() == Phi->getType() 1635b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick && !(ChainedPhis.count(Phi) 1636b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick || isExpandedAddRecExprPHI(OrigPhiRef, OrigInc, L)) 1637b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick && (ChainedPhis.count(Phi) 1638b5c26ef9da16052597d59a412eaae32098aa1be0Andrew 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) 1652b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick && ((isa<PHINode>(OrigInc) && isa<PHINode>(IsomorphicInc)) 1653b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick || hoistIVInc(OrigInc, IsomorphicInc))) { 1654204494149b6f846e8f173f525b129f5508076049Andrew Trick DEBUG_WITH_TYPE(DebugType, dbgs() 1655204494149b6f846e8f173f525b129f5508076049Andrew Trick << "INDVARS: Eliminated congruent iv.inc: " 1656204494149b6f846e8f173f525b129f5508076049Andrew Trick << *IsomorphicInc << '\n'); 1657ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Value *NewInc = OrigInc; 1658ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigInc->getType() != IsomorphicInc->getType()) { 1659dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick Instruction *IP = isa<PHINode>(OrigInc) 1660dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick ? (Instruction*)L->getHeader()->getFirstInsertionPt() 1661dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick : OrigInc->getNextNode(); 1662dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick IRBuilder<> Builder(IP); 1663ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Builder.SetCurrentDebugLocation(IsomorphicInc->getDebugLoc()); 1664ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick NewInc = Builder. 1665ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick CreateTruncOrBitCast(OrigInc, IsomorphicInc->getType(), IVName); 1666ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1667ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick IsomorphicInc->replaceAllUsesWith(NewInc); 1668204494149b6f846e8f173f525b129f5508076049Andrew Trick DeadInsts.push_back(IsomorphicInc); 1669204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1670204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1671204494149b6f846e8f173f525b129f5508076049Andrew Trick DEBUG_WITH_TYPE(DebugType, dbgs() 1672204494149b6f846e8f173f525b129f5508076049Andrew Trick << "INDVARS: Eliminated congruent iv: " << *Phi << '\n'); 1673204494149b6f846e8f173f525b129f5508076049Andrew Trick ++NumElim; 1674ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Value *NewIV = OrigPhiRef; 1675ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigPhiRef->getType() != Phi->getType()) { 1676ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick IRBuilder<> Builder(L->getHeader()->getFirstInsertionPt()); 1677ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Builder.SetCurrentDebugLocation(Phi->getDebugLoc()); 1678ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick NewIV = Builder.CreateTruncOrBitCast(OrigPhiRef, Phi->getType(), IVName); 1679ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1680ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Phi->replaceAllUsesWith(NewIV); 1681204494149b6f846e8f173f525b129f5508076049Andrew Trick DeadInsts.push_back(Phi); 1682204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1683204494149b6f846e8f173f525b129f5508076049Andrew Trick return NumElim; 1684204494149b6f846e8f173f525b129f5508076049Andrew Trick} 1685