ScalarEvolutionExpander.cpp revision b84d540bc9d70de00b791d0e0deab410d6ba3ad5
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) { 34919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // This function must be called with the builder having a valid insertion 35919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // point. It doesn't need to be the actual IP where the uses of the returned 36919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // cast will be added, but it must dominate such IP. 37919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // We use this precondition to assert that we can produce a cast that will 38919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // dominate all its uses. In particular, this is crussial for the case 39919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // where the builder's insertion point *is* the point where we were asked 40919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // to put the cast. 41919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // Since we don't know the the builder's insertion point is actually 42919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // where the uses will be added (only that it dominates it), we are 43919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // not allowed to move it. 44919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola BasicBlock::iterator BIP = Builder.GetInsertPoint(); 45919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola 46919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // FIXME: enable once our implementation of dominates is fixed. 47919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola // assert(BIP == IP || SE.DT->dominates(IP, BIP)); 48ef4c80e07baf02dd2a8f08db49c5634a06d3ca1eRafael Espindola 49485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Check to see if there is already a cast! 50485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); 51f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif UI != E; ++UI) { 52f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif User *U = *UI; 53f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif if (U->getType() == Ty) 5419e5ada58a8a07d3d6d67312550f6d0791d84c3cGabor Greif if (CastInst *CI = dyn_cast<CastInst>(U)) 55485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman if (CI->getOpcode() == Op) { 56b84d540bc9d70de00b791d0e0deab410d6ba3ad5Rafael Espindola // If the cast isn't where we want it, create a new cast at IP. 57b84d540bc9d70de00b791d0e0deab410d6ba3ad5Rafael Espindola // Likewise, do not reuse a cast at BIP because it must dominate 58b84d540bc9d70de00b791d0e0deab410d6ba3ad5Rafael Espindola // instructions that might be inserted before BIP. 59919a503458c18472984c7c37b305110c9ba3a782Rafael Espindola if (BasicBlock::iterator(CI) != IP || BIP == IP) { 60485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast, and leave the old cast in place in case 61485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // it is being used as an insert point. Clear its operand 62485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // so that it doesn't hold anything live. 63485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *NewCI = CastInst::Create(Op, V, Ty, "", IP); 64485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman NewCI->takeName(CI); 65485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->replaceAllUsesWith(NewCI); 66485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman CI->setOperand(0, UndefValue::get(V->getType())); 67485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(NewCI); 68485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return NewCI; 69485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 706f5fed253f58645bf45448893a585ffbd9914989Dan Gohman rememberInstruction(CI); 71485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return CI; 72485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman } 73f64f9cf7ec39ae91bca84dc6ad3c8fc3343b358aGabor Greif } 74485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 75485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Create a new cast. 76485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman Instruction *I = CastInst::Create(Op, V, Ty, V->getName(), IP); 77485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman rememberInstruction(I); 78485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return I; 79485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman} 80485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman 81267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// InsertNoopCastOfTo - Insert a cast of V to the specified type, 82267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// which must be possible with a noop cast, doing what we can to share 83267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman/// the casts. 84db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::InsertNoopCastOfTo(Value *V, Type *Ty) { 85267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction::CastOps Op = CastInst::getCastOpcode(V, false, Ty, false); 86267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert((Op == Instruction::BitCast || 87267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::PtrToInt || 88267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Op == Instruction::IntToPtr) && 89267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot perform non-noop casts!"); 90267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman assert(SE.getTypeSizeInBits(V->getType()) == SE.getTypeSizeInBits(Ty) && 91267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "InsertNoopCastOfTo cannot change sizes!"); 92267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 932d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman // Short-circuit unnecessary bitcasts. 9419154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (Op == Instruction::BitCast) { 9519154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (V->getType() == Ty) 9619154f457696f286b4a597179fa07e3b38ea0310Andrew Trick return V; 9719154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (CastInst *CI = dyn_cast<CastInst>(V)) { 9819154f457696f286b4a597179fa07e3b38ea0310Andrew Trick if (CI->getOperand(0)->getType() == Ty) 9919154f457696f286b4a597179fa07e3b38ea0310Andrew Trick return CI->getOperand(0); 10019154f457696f286b4a597179fa07e3b38ea0310Andrew Trick } 10119154f457696f286b4a597179fa07e3b38ea0310Andrew Trick } 102f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman // Short-circuit unnecessary inttoptr<->ptrtoint casts. 103267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if ((Op == Instruction::PtrToInt || Op == Instruction::IntToPtr) && 10480dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) { 105af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if (CastInst *CI = dyn_cast<CastInst>(V)) 106af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if ((CI->getOpcode() == Instruction::PtrToInt || 107af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman CI->getOpcode() == Instruction::IntToPtr) && 108af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getType()) == 109af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getOperand(0)->getType())) 110af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return CI->getOperand(0); 11180dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 11280dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman if ((CE->getOpcode() == Instruction::PtrToInt || 11380dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman CE->getOpcode() == Instruction::IntToPtr) && 11480dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getType()) == 11580dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman SE.getTypeSizeInBits(CE->getOperand(0)->getType())) 11680dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman return CE->getOperand(0); 11780dcdee0f48820ecea86c15768324945bb0d68d1Dan Gohman } 118f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman 119485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Fold a cast of a constant. 120ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 121baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Op, C, Ty); 1224c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman 123485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the argument at the beginning of the entry block, after 124485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // any bitcasts of other arguments. 125ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Argument *A = dyn_cast<Argument>(V)) { 126485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman BasicBlock::iterator IP = A->getParent()->getEntryBlock().begin(); 127485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman while ((isa<BitCastInst>(IP) && 128485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman isa<Argument>(cast<BitCastInst>(IP)->getOperand(0)) && 129485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman cast<BitCastInst>(IP)->getOperand(0) != A) || 130a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<DbgInfoIntrinsic>(IP) || 131a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(IP)) 132485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman ++IP; 133485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(A, Ty, Op, IP); 134ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 1353913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 136485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman // Cast the instruction immediately after the instruction. 137ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner Instruction *I = cast<Instruction>(V); 138ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner BasicBlock::iterator IP = I; ++IP; 139ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(I)) 140ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner IP = II->getNormalDest()->begin(); 141ef4c80e07baf02dd2a8f08db49c5634a06d3ca1eRafael Espindola while (isa<PHINode>(IP) || isa<LandingPadInst>(IP)) 142a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling ++IP; 143485c43fc478d5e16c55e14cb2586b56cc1c4c91fDan Gohman return ReuseOrCreateCast(I, Ty, Op, IP); 144ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner} 145ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 1467fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// InsertBinop - Insert the specified binary operator, doing a small amount 1477fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// of work to avoid inserting an obviously redundant operation. 148267a385342f2e7388f178b327dd87c5f29afd51bDan GohmanValue *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, 149267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *LHS, Value *RHS) { 1500f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman // Fold a binop with constant operands. 1510f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(LHS)) 1520f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(RHS)) 153baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, CLHS, CRHS); 1540f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman 1557fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner // Do a quick scan to see if we have this binop nearby. If so, reuse it. 1567fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner unsigned ScanLimit = 6; 157267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 158267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 159267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 160267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 1618a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz --IP; 1628a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz for (; ScanLimit; --IP, --ScanLimit) { 1638d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 1648d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 1658d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 1668d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 1675be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == (unsigned)Opcode && IP->getOperand(0) == LHS && 1685be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(1) == RHS) 1695be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 1708a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (IP == BlockBegin) break; 1718a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz } 1727fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner } 173267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 174087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 175087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 176087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 177087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 178087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 179087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 180087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(LHS) || !L->isLoopInvariant(RHS)) break; 181087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 182087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 183087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 184087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 185087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 186087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 187087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 1888a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // If we haven't found this binop, insert it. 189a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Instruction *BO = cast<Instruction>(Builder.CreateBinOp(Opcode, LHS, RHS)); 190df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel BO->setDebugLoc(SaveInsertPt->getDebugLoc()); 191a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(BO); 192087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 193087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 194087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 195087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 196087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 197cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return BO; 1987fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner} 1997fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner 2004a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// FactorOutConstant - Test if S is divisible by Factor, using signed 201453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// division. If so, update S with Factor divided out and return true. 2023f46a3abeedba8d517b4182de34c821d752db058Dan Gohman/// S need not be evenly divisible if a reasonable remainder can be 2034a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman/// computed. 204453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// TODO: When ScalarEvolution gets a SCEVSDivExpr, this can be made 205453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// unnecessary; in its place, just signed-divide Ops[i] by the scale and 206453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// check to see if the divide was folded. 2070bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic bool FactorOutConstant(const SCEV *&S, 2080bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *&Remainder, 209c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Factor, 210c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE, 211c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const TargetData *TD) { 212453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Everything is divisible by one. 213c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Factor->isOne()) 214c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 215c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 216c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // x/x == 1. 217c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (S == Factor) { 218deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman S = SE.getConstant(S->getType(), 1); 219453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 220c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 221453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 222453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // For a Constant, check for a multiple of the given factor. 2234a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S)) { 224c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // 0/x == 0. 225c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (C->isZero()) 226453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 227c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Check for divisibility. 228c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *FC = dyn_cast<SCEVConstant>(Factor)) { 229c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt *CI = 230c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ConstantInt::get(SE.getContext(), 231c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman C->getValue()->getValue().sdiv( 232c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 233c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the quotient is zero and the remainder is non-zero, reject 234c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the value at this scale. It will be considered for subsequent 235c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // smaller scales. 236c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!CI->isZero()) { 237c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Div = SE.getConstant(CI); 238c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = Div; 239c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder = 240c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(Remainder, 241c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().srem( 242c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue()))); 243c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 244c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 245453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 2464a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman } 247453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 248453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In a Mul, check if there is a constant operand which is a multiple 249453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // of the given factor. 250c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S)) { 251c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (TD) { 252c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, the size is known. Check if there is a constant 253c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // operand which is a multiple of the given factor. If so, we can 254c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // factor it. 255c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEVConstant *FC = cast<SCEVConstant>(Factor); 256c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0))) 257c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!C->getValue()->getValue().srem(FC->getValue()->getValue())) { 258f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 259c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[0] = 260c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getConstant(C->getValue()->getValue().sdiv( 261c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FC->getValue()->getValue())); 262c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 263c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 264c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 265c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 266c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Without TargetData, check if Factor can be factored out of any of the 267c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Mul's operands. If so, we can just remove it. 268c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) { 269c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *SOp = M->getOperand(i); 270deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(SOp->getType(), 0); 271c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (FactorOutConstant(SOp, Remainder, Factor, SE, TD) && 272c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Remainder->isZero()) { 273f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end()); 274c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman NewMulOps[i] = SOp; 275c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman S = SE.getMulExpr(NewMulOps); 276c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return true; 277c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 278453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 279c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 280c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 281453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 282453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // In an AddRec, check if both start and step are divisible. 283453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(S)) { 2840bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Step = A->getStepRecurrence(SE); 285deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *StepRem = SE.getConstant(Step->getType(), 0); 286c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Step, StepRem, Factor, SE, TD)) 2874a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2884a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman if (!StepRem->isZero()) 2894a4f767235dac50965fc266fb822d9a2e37d5212Dan Gohman return false; 2900bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *Start = A->getStart(); 291c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FactorOutConstant(Start, Remainder, Factor, SE, TD)) 292453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 2933228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: can use A->getNoWrapFlags(FlagNW) 2943228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick S = SE.getAddRecExpr(Start, Step, A->getLoop(), SCEV::FlagAnyWrap); 295453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return true; 296453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 297453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 298453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman return false; 299453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 300453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 301c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SimplifyAddOperands - Sort and simplify a list of add operands. NumAddRecs 302c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// is the number of SCEVAddRecExprs present, which are kept at the end of 303c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// the list. 304c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 305c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SimplifyAddOperands(SmallVectorImpl<const SCEV *> &Ops, 306db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 307c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 308c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman unsigned NumAddRecs = 0; 309c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = Ops.size(); i > 0 && isa<SCEVAddRecExpr>(Ops[i-1]); --i) 310c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ++NumAddRecs; 311c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Group Ops into non-addrecs and addrecs. 312c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> NoAddRecs(Ops.begin(), Ops.end() - NumAddRecs); 313c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs(Ops.end() - NumAddRecs, Ops.end()); 314c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Let ScalarEvolution sort and simplify the non-addrecs list. 315c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Sum = NoAddRecs.empty() ? 316deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getConstant(Ty, 0) : 317c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SE.getAddExpr(NoAddRecs); 318c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If it returned an add, use the operands. Otherwise it simplified 319c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // the sum into a single value, so just use that. 320f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.clear(); 321c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Sum)) 322403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 323f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman else if (!Sum->isZero()) 324f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman Ops.push_back(Sum); 325c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Then append the addrecs. 326403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 327c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 328c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 329c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// SplitAddRecs - Flatten a list of add operands, moving addrec start values 330c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// out to the top level. For example, convert {a + b,+,c} to a, b, {0,+,d}. 331c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// This helps expose more opportunities for folding parts of the expressions 332c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// into GEP indices. 333c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman/// 334c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohmanstatic void SplitAddRecs(SmallVectorImpl<const SCEV *> &Ops, 335db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 336c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ScalarEvolution &SE) { 337c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Find the addrecs. 338c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SmallVector<const SCEV *, 8> AddRecs; 339c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 340c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) { 341c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Start = A->getStart(); 342c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Start->isZero()) break; 343deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Zero = SE.getConstant(Ty, 0); 344c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AddRecs.push_back(SE.getAddRecExpr(Zero, 345c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman A->getStepRecurrence(SE), 3463228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick A->getLoop(), 3473228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: A->getNoWrapFlags(FlagNW) 3483228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 349c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Start)) { 350c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Zero; 351403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(Add->op_begin(), Add->op_end()); 352c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman e += Add->getNumOperands(); 353c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 354c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = Start; 355c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 356c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 357c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!AddRecs.empty()) { 358c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Add the addrecs onto the end of the list. 359403a8cdda5e76ea689693de16474650b4b0df818Dan Gohman Ops.append(AddRecs.begin(), AddRecs.end()); 360c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Resort the operand list, moving any constants to the front. 361c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 362c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 363c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman} 364c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 3654c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// expandAddToGEP - Expand an addition expression with a pointer type into 3664c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps 3674c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// BasicAliasAnalysis and other passes analyze the result. See the rules 3684c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for getelementptr vs. inttoptr in 3694c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// http://llvm.org/docs/LangRef.html#pointeraliasing 3704c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// for details. 37113c5e35222afe0895f0c5e68aa9f22f134ea437aDan Gohman/// 3723abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman/// Design note: The correctness of using getelementptr here depends on 3734c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as 3744c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// they may introduce pointer arithmetic which may not be safely converted 3754c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman/// into getelementptr. 376453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 377453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Design note: It might seem desirable for this function to be more 378453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-aware. If some of the indices are loop-invariant while others 379453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// aren't, it might seem desirable to emit multiple GEPs, keeping the 380453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of the overall computation outside the loop. 381453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// However, there are a few reasons this is not done here. Hoisting simple 382453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// arithmetic is a low-level optimization that often isn't very 383453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// important until late in the optimization process. In fact, passes 384453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// like InstructionCombining will combine GEPs, even if it means 385453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// pushing loop-invariant computation down into loops, so even if the 386453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEPs were split here, the work would quickly be undone. The 387453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// LoopStrengthReduction pass, which is usually run quite late (and 388453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// after the last InstructionCombining pass), takes care of hoisting 389453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// loop-invariant portions of expressions, after considering what 390453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// can be folded using target addressing modes. 391453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// 3920bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan GohmanValue *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin, 3930bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *const *op_end, 394db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner PointerType *PTy, 395db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty, 3965be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *V) { 397db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ElTy = PTy->getElementType(); 3985be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman SmallVector<Value *, 4> GepIndices; 3990bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> Ops(op_begin, op_end); 4005be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman bool AnyNonZeroIndices = false; 4015be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 402c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Split AddRecs up into parts as either of the parts may be usable 403c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // without the other. 404c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman SplitAddRecs(Ops, Ty, SE); 405c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 406eb35699e642f2c021f04154bdb4bd90a1afb3baaBob Wilson // Descend down the pointer's type and attempt to convert the other 4075be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // operands into GEP indices, at each level. The first index in a GEP 4085be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // indexes into the array implied by the pointer operand; the rest of 4095be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the indices index into the element or field type selected by the 4105be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // preceding index. 4115be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (;;) { 412c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If the scale size is not 0, attempt to factor out a scale for 413c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // array indexing. 4140bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> ScaledOps; 415150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (ElTy->isSized()) { 4164f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const SCEV *ElSize = SE.getSizeOfExpr(ElTy); 417150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ElSize->isZero()) { 418150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SmallVector<const SCEV *, 8> NewOps; 419150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 420150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman const SCEV *Op = Ops[i]; 421deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *Remainder = SE.getConstant(Ty, 0); 422150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (FactorOutConstant(Op, Remainder, ElSize, SE, SE.TD)) { 423150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // Op now has ElSize factored out. 424150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman ScaledOps.push_back(Op); 425150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!Remainder->isZero()) 426150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Remainder); 427150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman AnyNonZeroIndices = true; 428150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } else { 429150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // The operand was not divisible, so add it to the list of operands 430150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // we'll scan next iteration. 431150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman NewOps.push_back(Ops[i]); 432150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 433150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman } 434150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman // If we made any changes, update Ops. 435150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman if (!ScaledOps.empty()) { 436150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman Ops = NewOps; 437150dfa87113e51881c75676edd8e3549eb702d99Dan Gohman SimplifyAddOperands(Ops, Ty, SE); 4385be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 439c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4405be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 441c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 442c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Record the scaled array index for this level of the type. If 443c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // we didn't find any operands that could be factored, tentatively 444c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // assume that element zero was selected (since the zero offset 445c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // would obviously be folded away). 4465be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Value *Scaled = ScaledOps.empty() ? 447a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant::getNullValue(Ty) : 4485be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman expandCodeFor(SE.getAddExpr(ScaledOps), Ty); 4495be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman GepIndices.push_back(Scaled); 4505be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 4515be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Collect struct field index operands. 452db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner while (StructType *STy = dyn_cast<StructType>(ElTy)) { 453c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman bool FoundFieldNo = false; 454c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // An empty struct has no fields. 455c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (STy->getNumElements() == 0) break; 456c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (SE.TD) { 457c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // With TargetData, field offsets are known. See if a constant offset 458c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // falls within any of the struct fields. 459c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (Ops.empty()) break; 4605be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[0])) 4615be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (SE.getTypeSizeInBits(C->getType()) <= 64) { 4625be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman const StructLayout &SL = *SE.TD->getStructLayout(STy); 4635be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman uint64_t FullOffset = C->getValue()->getZExtValue(); 4645be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (FullOffset < SL.getSizeInBytes()) { 4655be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(FullOffset); 4661d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson GepIndices.push_back( 4671d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson ConstantInt::get(Type::getInt32Ty(Ty->getContext()), ElIdx)); 4685be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = STy->getTypeAtIndex(ElIdx); 4695be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops[0] = 4706de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman SE.getConstant(Ty, FullOffset - SL.getElementOffset(ElIdx)); 4715be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman AnyNonZeroIndices = true; 472c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 4735be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 4745be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 475c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } else { 4760f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman // Without TargetData, just check for an offsetof expression of the 477c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // appropriate struct type. 478c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman for (unsigned i = 0, e = Ops.size(); i != e; ++i) 4790f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Ops[i])) { 480db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *CTy; 4810f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman Constant *FieldNo; 4824f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (U->isOffsetOf(CTy, FieldNo) && CTy == STy) { 4830f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman GepIndices.push_back(FieldNo); 4840f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman ElTy = 4850f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman STy->getTypeAtIndex(cast<ConstantInt>(FieldNo)->getZExtValue()); 486c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Ops[i] = SE.getConstant(Ty, 0); 487c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman AnyNonZeroIndices = true; 488c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman FoundFieldNo = true; 489c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 490c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 4910f5efe56258f8cd6ceff4d7955a5d80144cd9cb0Dan Gohman } 4925be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 493c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If no struct field offsets were found, tentatively assume that 494c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // field zero was selected (since the zero offset would obviously 495c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // be folded away). 496c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!FoundFieldNo) { 497c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ElTy = STy->getTypeAtIndex(0u); 498c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman GepIndices.push_back( 499c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Constant::getNullValue(Type::getInt32Ty(Ty->getContext()))); 500c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 501c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 5025be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 503db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (ArrayType *ATy = dyn_cast<ArrayType>(ElTy)) 5045be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman ElTy = ATy->getElementType(); 505c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman else 506c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman break; 5075be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5085be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 5093f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // If none of the operands were convertible to proper GEP indices, cast 5105be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // the base to i8* and do an ugly getelementptr with that. It's still 5115be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // better than ptrtoint+arithmetic+inttoptr at least. 5125be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (!AnyNonZeroIndices) { 513c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Cast the base to i8*. 5145be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, 515ac53a0b272452013124bfc70480aea5e41b60f40Duncan Sands Type::getInt8PtrTy(Ty->getContext(), PTy->getAddressSpace())); 516c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman 517705b48d960dff1a96ac40d0cf932eb465b9a550aRafael Espindola assert(!isa<Instruction>(V) || 518705b48d960dff1a96ac40d0cf932eb465b9a550aRafael Espindola SE.DT->properlyDominates(cast<Instruction>(V), 519161fb5d936e8feb730b5598243e20c76d3dc62f7Rafael Espindola Builder.GetInsertPoint())); 5204b04578d65e38cdb5077de2498889e4a174ccdfdRafael Espindola 521c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Expand the operands for a plain byte offset. 52292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *Idx = expandCodeFor(SE.getAddExpr(Ops), Ty); 5235be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 5245be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Fold a GEP with constant operands. 5255be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(V)) 5265be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(Idx)) 527dab3d29605a5c83db41b28176273ef55961120c1Jay Foad return ConstantExpr::getGetElementPtr(CLHS, CRHS); 5285be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 5295be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman // Do a quick scan to see if we have this GEP nearby. If so, reuse it. 5305be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman unsigned ScanLimit = 6; 531267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator BlockBegin = Builder.GetInsertBlock()->begin(); 532267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman // Scanning starts from the last instruction before the insertion point. 533267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator IP = Builder.GetInsertPoint(); 534267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (IP != BlockBegin) { 5355be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman --IP; 5365be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman for (; ScanLimit; --IP, --ScanLimit) { 5378d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // Don't count dbg.value against the ScanLimit, to avoid perturbing the 5388d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen // generated code. 5398d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen if (isa<DbgInfoIntrinsic>(IP)) 5408d50ea760322630dbb9ab6436ca356b279adee10Dale Johannesen ScanLimit++; 5415be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP->getOpcode() == Instruction::GetElementPtr && 5425be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman IP->getOperand(0) == V && IP->getOperand(1) == Idx) 5435be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return IP; 5445be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (IP == BlockBegin) break; 5455be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5465be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5475be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 548087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 549087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 550087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 551087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 552087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 553087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 554087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V) || !L->isLoopInvariant(Idx)) break; 555087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 556087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 557087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 558087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 559087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 560087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 561087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 562c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Emit a GEP. 563c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *GEP = Builder.CreateGEP(V, Idx, "uglygep"); 564a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 565087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 566087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 567087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 568087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 569087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 5705be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return GEP; 5715be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 5725be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 573087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Save the original insertion point so we can restore it when we're done. 574087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 575087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 576087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 577087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Move the insertion point out of as many loops as we can. 578087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman while (const Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock())) { 579087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(V)) break; 580087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 581087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool AnyIndexNotLoopInvariant = false; 582087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<Value *>::const_iterator I = GepIndices.begin(), 583087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E = GepIndices.end(); I != E; ++I) 584087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!L->isLoopInvariant(*I)) { 585087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman AnyIndexNotLoopInvariant = true; 586087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 587087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 588087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (AnyIndexNotLoopInvariant) 589087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman break; 590087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 591087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman BasicBlock *Preheader = L->getLoopPreheader(); 592087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Preheader) break; 593087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 594087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Ok, move up a level. 595087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Builder.SetInsertPoint(Preheader, Preheader->getTerminator()); 596087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 597087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 598d6aa02de1076c801ac41295156a2379637976918Dan Gohman // Insert a pretty getelementptr. Note that this GEP is not marked inbounds, 599d6aa02de1076c801ac41295156a2379637976918Dan Gohman // because ScalarEvolution may have changed the address arithmetic to 600d6aa02de1076c801ac41295156a2379637976918Dan Gohman // compute a value which is beyond the end of the allocated object. 601a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Casted = V; 602a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (V->getType() != PTy) 603a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Casted = InsertNoopCastOfTo(Casted, PTy); 604a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *GEP = Builder.CreateGEP(Casted, 6050a2a60ace9b79164b71794ce7ff981171c61e442Jay Foad GepIndices, 606267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman "scevgep"); 6075be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman Ops.push_back(SE.getUnknown(GEP)); 608a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(GEP); 609087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 610087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Restore the original insert point. 611087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (SaveInsertBB) 612087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 613087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 6145be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return expand(SE.getAddExpr(Ops)); 6155be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman} 6165be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 617087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// PickMostRelevantLoop - Given two loops pick the one that's most relevant for 618087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// SCEV expansion. If they are nested, this is the most nested. If they are 619087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// neighboring, pick the later. 620087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanstatic const Loop *PickMostRelevantLoop(const Loop *A, const Loop *B, 621087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT) { 622087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!A) return B; 623087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!B) return A; 624087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (A->contains(B)) return B; 625087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (B->contains(A)) return A; 626087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(A->getHeader(), B->getHeader())) return B; 627087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (DT.dominates(B->getHeader(), A->getHeader())) return A; 628087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return A; // Arbitrarily break the tie. 629087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 630087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 6319c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman/// getRelevantLoop - Get the most relevant loop associated with the given 632087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// expression, according to PickMostRelevantLoop. 6339c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohmanconst Loop *SCEVExpander::getRelevantLoop(const SCEV *S) { 6349c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // Test whether we've already computed the most relevant loop for this SCEV. 6359c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman std::pair<DenseMap<const SCEV *, const Loop *>::iterator, bool> Pair = 6369c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman RelevantLoops.insert(std::make_pair(S, static_cast<const Loop *>(0))); 6379c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (!Pair.second) 6389c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return Pair.first->second; 6399c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman 640087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<SCEVConstant>(S)) 6419c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // A constant has no relevant loops. 642087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 643087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) { 644087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const Instruction *I = dyn_cast<Instruction>(U->getValue())) 6459c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return Pair.first->second = SE.LI->getLoopFor(I->getParent()); 6469c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman // A non-instruction has no relevant loops. 647087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return 0; 648087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 649087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVNAryExpr *N = dyn_cast<SCEVNAryExpr>(S)) { 650087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *L = 0; 651087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) 652087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman L = AR->getLoop(); 653087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SCEVNAryExpr::op_iterator I = N->op_begin(), E = N->op_end(); 654087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I != E; ++I) 6559c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman L = PickMostRelevantLoop(L, getRelevantLoop(*I), *SE.DT); 6569c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[N] = L; 6579c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman } 6589c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(S)) { 6599c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman const Loop *Result = getRelevantLoop(C->getOperand()); 6609c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[C] = Result; 6619c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman } 6629c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman if (const SCEVUDivExpr *D = dyn_cast<SCEVUDivExpr>(S)) { 6639c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman const Loop *Result = 6649c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman PickMostRelevantLoop(getRelevantLoop(D->getLHS()), 6659c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman getRelevantLoop(D->getRHS()), 6669c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman *SE.DT); 6679c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman return RelevantLoops[D] = Result; 668087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 669087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman llvm_unreachable("Unexpected SCEV type!"); 670087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman} 671c4f7ec85ecb760fff2b702c6deb06506b968ba4fDan Gohman 672b35798347ea87b8b6d36155b211016a7769f01abDan Gohmannamespace { 673b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 674087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman/// LoopCompare - Compare loops by PickMostRelevantLoop. 675087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanclass LoopCompare { 676087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman DominatorTree &DT; 677087bd1e3a12893873761736bf0f905a350e9e708Dan Gohmanpublic: 678087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman explicit LoopCompare(DominatorTree &dt) : DT(dt) {} 679087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 680087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman bool operator()(std::pair<const Loop *, const SCEV *> LHS, 681087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::pair<const Loop *, const SCEV *> RHS) const { 682bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // Keep pointer operands sorted at the end. 683bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (LHS.second->getType()->isPointerTy() != 684bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman RHS.second->getType()->isPointerTy()) 685bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman return LHS.second->getType()->isPointerTy(); 686bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman 687087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Compare loops with PickMostRelevantLoop. 688087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (LHS.first != RHS.first) 689087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return PickMostRelevantLoop(LHS.first, RHS.first, DT) != LHS.first; 690087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 691087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // If one operand is a non-constant negative and the other is not, 692087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // put the non-constant negative on the right so that a sub can 693087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // be used instead of a negate and add. 694f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick if (LHS.second->isNonConstantNegative()) { 695f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick if (!RHS.second->isNonConstantNegative()) 696087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 697f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick } else if (RHS.second->isNonConstantNegative()) 698087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return true; 699087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 700087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Otherwise they are equivalent according to this comparison. 701087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return false; 702c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman } 703087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman}; 7045be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 705b35798347ea87b8b6d36155b211016a7769f01abDan Gohman} 706b35798347ea87b8b6d36155b211016a7769f01abDan Gohman 707087bd1e3a12893873761736bf0f905a350e9e708Dan GohmanValue *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { 708db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 709e24fa64d52330626553298f56ba5aa702624c282Dan Gohman 710087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the add operands in a loop, along with their associated loops. 711087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal, and 712087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // so that pointer operands are inserted first, which the code below relies on 713087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // to form more involved GEPs. 714087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 715087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVAddExpr::op_iterator> I(S->op_end()), 716087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 7179c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I)); 718087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 719087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants and 720087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // pointer operands precede non-pointer operands. 721087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 722087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 723087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to add all the operands. Hoist as much as possible 724087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops, and form meaningful getelementptrs where possible. 725087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Sum = 0; 726087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 727087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 728087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const Loop *CurLoop = I->first; 729087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 730087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Sum) { 731087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 732087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expand(Op); 733087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 734db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner } else if (PointerType *PTy = dyn_cast<PointerType>(Sum->getType())) { 735087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum expression is a pointer. Try to form a getelementptr 736087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // at this level with that as the base. 737087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 738bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman for (; I != E && I->first == CurLoop; ++I) { 739bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // If the operand is SCEVUnknown and not instructions, peek through 740bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman // it, to enable more of it to be folded into the GEP. 741bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman const SCEV *X = I->second; 742bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(X)) 743bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman if (!isa<Instruction>(U->getValue())) 744bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman X = SE.getSCEV(U->getValue()); 745bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman NewOps.push_back(X); 746bb5d92741b2835eff25e4524bc6a5b0fb4fda855Dan Gohman } 747087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum); 748db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner } else if (PointerType *PTy = dyn_cast<PointerType>(Op->getType())) { 749087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // The running sum is an integer, and there's a pointer at this level. 750f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // Try to form a getelementptr. If the running sum is instructions, 751f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman // use a SCEVUnknown to avoid re-analyzing them. 752087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<const SCEV *, 4> NewOps; 753f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman NewOps.push_back(isa<Instruction>(Sum) ? SE.getUnknown(Sum) : 754f8d0578e4cbd5922696c92f5068c5513d8e8d60eDan Gohman SE.getSCEV(Sum)); 755087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (++I; I != E && I->first == CurLoop; ++I) 756087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman NewOps.push_back(I->second); 757087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, expand(Op)); 758f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick } else if (Op->isNonConstantNegative()) { 759087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a negate and add, just do a subtract. 760a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(SE.getNegativeSCEV(Op), Ty); 761087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 762087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Sub, Sum, W); 763087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 764a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 765087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple add. 766a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *W = expandCodeFor(Op, Ty); 767087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertNoopCastOfTo(Sum, Ty); 768087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 769087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Sum)) std::swap(Sum, W); 770087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Sum = InsertBinop(Instruction::Add, Sum, W); 771087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 772a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 7732d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 774087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 775087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Sum; 776e24fa64d52330626553298f56ba5aa702624c282Dan Gohman} 7775be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman 778890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) { 779db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 780087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 781087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Collect all the mul operands in a loop, along with their associated loops. 782087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Iterate in reverse so that constants are emitted last, all else equal. 783087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops; 784087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (std::reverse_iterator<SCEVMulExpr::op_iterator> I(S->op_end()), 785087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman E(S->op_begin()); I != E; ++I) 7869c9fcfc719158a46cb2e41b66d7dc1a63cd48d74Dan Gohman OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I)); 787087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 788087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Sort by loop. Use a stable sort so that constants follow non-constants. 789087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT)); 790087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman 791087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Emit instructions to mul all the operands. Hoist as much as possible 792087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // out of loops. 793087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *Prod = 0; 794087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman for (SmallVectorImpl<std::pair<const Loop *, const SCEV *> >::iterator 795087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman I = OpsAndLoops.begin(), E = OpsAndLoops.end(); I != E; ) { 796087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman const SCEV *Op = I->second; 797087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (!Prod) { 798087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // This is the first operand. Just expand it. 799087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = expand(Op); 800087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 801087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else if (Op->isAllOnesValue()) { 802087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Instead of doing a multiply by negative one, just do a negate. 803087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 804087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Sub, Constant::getNullValue(Ty), Prod); 805087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 806087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } else { 807087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // A simple mul. 808087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Value *W = expandCodeFor(Op, Ty); 809087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertNoopCastOfTo(Prod, Ty); 810087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman // Canonicalize a constant to the RHS. 811087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman if (isa<Constant>(Prod)) std::swap(Prod, W); 812087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman Prod = InsertBinop(Instruction::Mul, Prod, W); 813087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman ++I; 814087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman } 8152d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 8162d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 817087bd1e3a12893873761736bf0f905a350e9e708Dan Gohman return Prod; 81836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 81936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 820890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) { 821db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 8222d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 82392fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *LHS = expandCodeFor(S->getLHS(), Ty); 824890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getRHS())) { 8256177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky const APInt &RHS = SC->getValue()->getValue(); 8266177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky if (RHS.isPowerOf2()) 8276177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky return InsertBinop(Instruction::LShr, LHS, 828eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson ConstantInt::get(Ty, RHS.logBase2())); 8296177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky } 8306177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 83192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getRHS(), Ty); 832267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman return InsertBinop(Instruction::UDiv, LHS, RHS); 8336177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky} 8346177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 835453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// Move parts of Base into Rest to leave Base with the minimal 836453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// expression that provides a pointer operand suitable for a 837453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman/// GEP expansion. 8380bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohmanstatic void ExposePointerBase(const SCEV *&Base, const SCEV *&Rest, 839453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ScalarEvolution &SE) { 840453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Base)) { 841453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getStart(); 842453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(Rest, 843deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman SE.getAddRecExpr(SE.getConstant(A->getType(), 0), 844453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman A->getStepRecurrence(SE), 8453228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick A->getLoop(), 8463228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: A->getNoWrapFlags(FlagNW) 8473228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 848453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 849453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(Base)) { 850453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Base = A->getOperand(A->getNumOperands()-1); 8510bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman SmallVector<const SCEV *, 8> NewAddOps(A->op_begin(), A->op_end()); 852453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman NewAddOps.back() = Rest; 853453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman Rest = SE.getAddExpr(NewAddOps); 854453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman ExposePointerBase(Base, Rest, SE); 855453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 856453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman} 857453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 858c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// Determine if this is a well-behaved chain of instructions leading back to 859c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick/// the PHI. If so, it may be reused by expanded expressions. 860c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trickbool SCEVExpander::isNormalAddRecExprPHI(PHINode *PN, Instruction *IncV, 861c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick const Loop *L) { 862c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getNumOperands() == 0 || isa<PHINode>(IncV) || 863c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick (isa<CastInst>(IncV) && !isa<BitCastInst>(IncV))) 864c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 865c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // If any of the operands don't dominate the insert position, bail. 866c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Addrec operands are always loop-invariant, so this can only happen 867c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // if there are instructions which haven't been hoisted. 868c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (L == IVIncInsertLoop) { 869c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (User::op_iterator OI = IncV->op_begin()+1, 870c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick OE = IncV->op_end(); OI != OE; ++OI) 871c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (Instruction *OInst = dyn_cast<Instruction>(OI)) 872c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!SE.DT->dominates(OInst, IVIncInsertPos)) 873c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 874c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 875c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Advance to the next instruction. 876c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick IncV = dyn_cast<Instruction>(IncV->getOperand(0)); 877c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!IncV) 878c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 879c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 880c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->mayHaveSideEffects()) 881c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 882c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 883c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV != PN) 884c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return true; 885c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 886c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return isNormalAddRecExprPHI(PN, IncV, L); 887c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick} 888c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 889b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// getIVIncOperand returns an induction variable increment's induction 890b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// variable operand. 891b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// 892b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// If allowScale is set, any type of GEP is allowed as long as the nonIV 893b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// operands dominate InsertPos. 894b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// 895b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// If allowScale is not set, ensure that a GEP increment conforms to one of the 896b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// simple patterns generated by getAddRecExprPHILiterally and 897b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// expandAddtoGEP. If the pattern isn't recognized, return NULL. 898b5c26ef9da16052597d59a412eaae32098aa1be0Andrew TrickInstruction *SCEVExpander::getIVIncOperand(Instruction *IncV, 899b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick Instruction *InsertPos, 900b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick bool allowScale) { 901b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (IncV == InsertPos) 902b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 90364925c55c65f9345a69fb67db07aa62cfb723577Andrew Trick 904c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick switch (IncV->getOpcode()) { 905b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick default: 906b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 907c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Check for a simple Add/Sub or GEP of a loop invariant step. 908c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::Add: 909b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick case Instruction::Sub: { 910b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick Instruction *OInst = dyn_cast<Instruction>(IncV->getOperand(1)); 911b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (!OInst || SE.DT->properlyDominates(OInst, InsertPos)) 912b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return dyn_cast<Instruction>(IncV->getOperand(0)); 913b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 914b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 915c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick case Instruction::BitCast: 916b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return dyn_cast<Instruction>(IncV->getOperand(0)); 917b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick case Instruction::GetElementPtr: 918c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (Instruction::op_iterator I = IncV->op_begin()+1, E = IncV->op_end(); 919c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick I != E; ++I) { 920c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (isa<Constant>(*I)) 921c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 922b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (Instruction *OInst = dyn_cast<Instruction>(*I)) { 923b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (!SE.DT->properlyDominates(OInst, InsertPos)) 924b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 925b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 926b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (allowScale) { 927b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // allow any kind of GEP as long as it can be hoisted. 928b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick continue; 929b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 930b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // This must be a pointer addition of constants (pretty), which is already 931b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // handled, or some number of address-size elements (ugly). Ugly geps 932b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // have 2 operands. i1* is used by the expander to represent an 933b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // address-size element. 934c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getNumOperands() != 2) 935b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 936365c9f1ff55bef134c6b9707f7df44d680ddabeaAndrew Trick unsigned AS = cast<PointerType>(IncV->getType())->getAddressSpace(); 937c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (IncV->getType() != Type::getInt1PtrTy(SE.getContext(), AS) 938c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick && IncV->getType() != Type::getInt8PtrTy(SE.getContext(), AS)) 939b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return NULL; 940c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick break; 941c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 942b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return dyn_cast<Instruction>(IncV->getOperand(0)); 943c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 944b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick} 945b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick 946b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// hoistStep - Attempt to hoist a simple IV increment above InsertPos to make 947b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// it available to other uses in this loop. Recursively hoist any operands, 948b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// until we reach a value that dominates InsertPos. 949b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trickbool SCEVExpander::hoistIVInc(Instruction *IncV, Instruction *InsertPos) { 950b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (SE.DT->properlyDominates(IncV, InsertPos)) 951b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return true; 952b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick 953b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // InsertPos must itself dominate IncV so that IncV's new position satisfies 954b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // its existing users. 955b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (!SE.DT->dominates(InsertPos->getParent(), IncV->getParent())) 956c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return false; 957b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick 958b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // Check that the chain of IV operands leading back to Phi can be hoisted. 959b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick SmallVector<Instruction*, 4> IVIncs; 960b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick for(;;) { 961b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick Instruction *Oper = getIVIncOperand(IncV, InsertPos, /*allowScale*/true); 962b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (!Oper) 963b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return false; 964b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // IncV is safe to hoist. 965b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick IVIncs.push_back(IncV); 966b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick IncV = Oper; 967b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (SE.DT->properlyDominates(IncV, InsertPos)) 968b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick break; 969b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 970b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick for (SmallVectorImpl<Instruction*>::reverse_iterator I = IVIncs.rbegin(), 971b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick E = IVIncs.rend(); I != E; ++I) { 972b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick (*I)->moveBefore(InsertPos); 973b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 974b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return true; 975b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick} 976b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick 977b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// Determine if this cyclic phi is in a form that would have been generated by 978b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// LSR. We don't care if the phi was actually expanded in this pass, as long 979b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// as it is in a low-cost form, for example, no implied multiplication. This 980b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// should match any patterns generated by getAddRecExprPHILiterally and 981b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick/// expandAddtoGEP. 982b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trickbool SCEVExpander::isExpandedAddRecExprPHI(PHINode *PN, Instruction *IncV, 983b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick const Loop *L) { 984b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick for(Instruction *IVOper = IncV; 985b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick (IVOper = getIVIncOperand(IVOper, L->getLoopPreheader()->getTerminator(), 986b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick /*allowScale=*/false));) { 987b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (IVOper == PN) 988b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return true; 989c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 990b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick return false; 991c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick} 992c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 993553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick/// expandIVInc - Expand an IV increment at Builder's current InsertPos. 994553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick/// Typically this is the LatchBlock terminator or IVIncInsertPos, but we may 995553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick/// need to materialize IV increments elsewhere to handle difficult situations. 996553fe05f236f46fe27b7fcfa822b06367d50183eAndrew TrickValue *SCEVExpander::expandIVInc(PHINode *PN, Value *StepV, const Loop *L, 997553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Type *ExpandTy, Type *IntTy, 998553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick bool useSubtract) { 999553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Value *IncV; 1000553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If the PHI is a pointer, use a GEP, otherwise use an add or sub. 1001553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (ExpandTy->isPointerTy()) { 1002553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick PointerType *GEPPtrTy = cast<PointerType>(ExpandTy); 1003553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If the step isn't constant, don't use an implicitly scaled GEP, because 1004553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // that would require a multiply inside the loop. 1005553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (!isa<ConstantInt>(StepV)) 1006553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick GEPPtrTy = PointerType::get(Type::getInt1Ty(SE.getContext()), 1007553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick GEPPtrTy->getAddressSpace()); 1008553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick const SCEV *const StepArray[1] = { SE.getSCEV(StepV) }; 1009553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick IncV = expandAddToGEP(StepArray, StepArray+1, GEPPtrTy, IntTy, PN); 1010553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (IncV->getType() != PN->getType()) { 1011553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick IncV = Builder.CreateBitCast(IncV, PN->getType()); 1012553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick rememberInstruction(IncV); 1013553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } 1014553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } else { 1015553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick IncV = useSubtract ? 1016553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Builder.CreateSub(PN, StepV, Twine(IVName) + ".iv.next") : 1017553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Builder.CreateAdd(PN, StepV, Twine(IVName) + ".iv.next"); 1018553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick rememberInstruction(IncV); 1019553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } 1020553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick return IncV; 1021553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick} 1022553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick 1023a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// getAddRecExprPHILiterally - Helper for expandAddRecExprLiterally. Expand 1024a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// the base addrec, which is the addrec without any non-loop-dominating 1025a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman/// values, and return the PHI. 1026a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanPHINode * 1027a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanSCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized, 1028a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L, 1029db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ExpandTy, 1030db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntTy) { 103193a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer assert((!IVIncInsertLoop||IVIncInsertPos) && "Uninitialized insert position"); 1032d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 1033a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Reuse a previously-inserted PHI, if present. 1034c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick BasicBlock *LatchBlock = L->getLoopLatch(); 1035c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (LatchBlock) { 1036c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick for (BasicBlock::iterator I = L->getHeader()->begin(); 1037c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick PHINode *PN = dyn_cast<PHINode>(I); ++I) { 1038c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!SE.isSCEVable(PN->getType()) || 1039c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick (SE.getEffectiveSCEVType(PN->getType()) != 1040c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick SE.getEffectiveSCEVType(Normalized->getType())) || 1041c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick SE.getSCEV(PN) != Normalized) 1042c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 1043c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 1044c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick Instruction *IncV = 1045c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)); 1046c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick 1047c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (LSRMode) { 1048365c9f1ff55bef134c6b9707f7df44d680ddabeaAndrew Trick if (!isExpandedAddRecExprPHI(PN, IncV, L)) 1049c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 1050b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (L == IVIncInsertLoop && !hoistIVInc(IncV, IVIncInsertPos)) 1051b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick continue; 1052c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 1053c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick else { 1054c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick if (!isNormalAddRecExprPHI(PN, IncV, L)) 1055c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick continue; 1056b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (L == IVIncInsertLoop) 1057b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick do { 1058b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick if (SE.DT->dominates(IncV, IVIncInsertPos)) 1059b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick break; 1060b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // Make sure the increment is where we want it. But don't move it 1061b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // down past a potential existing post-inc user. 1062b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick IncV->moveBefore(IVIncInsertPos); 1063b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick IVIncInsertPos = IncV; 1064b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick IncV = cast<Instruction>(IncV->getOperand(0)); 1065b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } while (IncV != PN); 1066c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 1067c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Ok, the add recurrence looks usable. 1068c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Remember this PHI, even in post-inc mode. 1069c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick InsertedValues.insert(PN); 1070c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick // Remember the increment. 1071c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick rememberInstruction(IncV); 1072c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick return PN; 1073c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 1074c5701910604cdf65811fabd31d41e38f1d1d4eb1Andrew Trick } 1075a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1076a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Save the original insertion point so we can restore it when we're done. 1077a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1078a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1079a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1080ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // Another AddRec may need to be recursively expanded below. For example, if 1081ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // this AddRec is quadratic, the StepV may itself be an AddRec in this 1082ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // loop. Remove this loop from the PostIncLoops set before expanding such 1083ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // AddRecs. Otherwise, we cannot find a valid position for the step 1084ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // (i.e. StepV can never dominate its loop header). Ideally, we could do 1085ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // SavedIncLoops.swap(PostIncLoops), but we generally have a single element, 1086ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // so it's not worth implementing SmallPtrSet::swap. 1087ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick PostIncLoopSet SavedPostIncLoops = PostIncLoops; 1088ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick PostIncLoops.clear(); 1089ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick 1090a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand code for the start value. 1091a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StartV = expandCodeFor(Normalized->getStart(), ExpandTy, 1092a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman L->getHeader()->begin()); 1093a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1094d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick // StartV must be hoisted into L's preheader to dominate the new phi. 109593a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer assert(!isa<Instruction>(StartV) || 109693a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer SE.DT->properlyDominates(cast<Instruction>(StartV)->getParent(), 109793a896e2e36480d55de3bab53e68581e08526344Benjamin Kramer L->getHeader())); 1098d152d03a476b8d0d4b26577db26e2ba76034b0f3Andrew Trick 1099553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Expand code for the step value. Do this before creating the PHI so that PHI 1100553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // reuse code doesn't see an incomplete PHI. 1101a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 1102553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If the stride is negative, insert a sub instead of an add for the increment 1103553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // (unless it's a constant, because subtracts of constants are canonicalized 1104553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // to adds). 1105f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick bool useSubtract = !ExpandTy->isPointerTy() && Step->isNonConstantNegative(); 1106553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (useSubtract) 1107a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Step = SE.getNegativeSCEV(Step); 1108553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Expand the step somewhere that dominates the loop header. 1109a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *StepV = expandCodeFor(Step, IntTy, L->getHeader()->begin()); 1110a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1111a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the PHI. 1112d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad BasicBlock *Header = L->getHeader(); 1113d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad Builder.SetInsertPoint(Header, Header->begin()); 1114d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad pred_iterator HPB = pred_begin(Header), HPE = pred_end(Header); 11155e7645be4c9dd2193add44d30b5fef8036d7a3ceAndrew Trick PHINode *PN = Builder.CreatePHI(ExpandTy, std::distance(HPB, HPE), 1116dc8e546048db2f7ff5656742b2b26975098a11a0Andrew Trick Twine(IVName) + ".iv"); 1117a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(PN); 1118a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1119a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Create the step instructions and populate the PHI. 1120d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad for (pred_iterator HPI = HPB; HPI != HPE; ++HPI) { 1121a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *Pred = *HPI; 1122a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1123a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Add a start value. 1124a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!L->contains(Pred)) { 1125a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(StartV, Pred); 1126a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman continue; 1127a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1128a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1129553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Create a step value and add it to the PHI. 1130553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // If IVIncInsertLoop is non-null and equal to the addrec's loop, insert the 1131553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // instructions at IVIncInsertPos. 1132a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Instruction *InsertPos = L == IVIncInsertLoop ? 1133a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman IVIncInsertPos : Pred->getTerminator(); 1134c5ecbdc1896f1cc089372feef3191ace2f840898Devang Patel Builder.SetInsertPoint(InsertPos); 1135553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Value *IncV = expandIVInc(PN, StepV, L, ExpandTy, IntTy, useSubtract); 1136553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick 1137a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PN->addIncoming(IncV, Pred); 1138a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1139a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1140a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Restore the original insert point. 1141a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (SaveInsertBB) 1142455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1143a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1144ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // After expanding subexpressions, restore the PostIncLoops set so the caller 1145ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick // can ensure that IVIncrement dominates the current uses. 1146ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick PostIncLoops = SavedPostIncLoops; 1147ba3c0bc364a31bfbcc570504aae2172914b1fe9fAndrew Trick 1148a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Remember this PHI, even in post-inc mode. 1149a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman InsertedValues.insert(PN); 1150a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1151a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return PN; 1152a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1153a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1154a10756ee657a4d43a48cca5c166919093930ed6bDan GohmanValue *SCEVExpander::expandAddRecExprLiterally(const SCEVAddRecExpr *S) { 1155db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *STy = S->getType(); 1156db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntTy = SE.getEffectiveSCEVType(STy); 1157a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const Loop *L = S->getLoop(); 1158a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1159a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Determine a normalized form of this expression, which is the expression 1160a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // before any post-inc adjustment is made. 1161a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEVAddRecExpr *Normalized = S; 1162448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (PostIncLoops.count(L)) { 1163448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman PostIncLoopSet Loops; 1164448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops.insert(L); 1165448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Normalized = 1166448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman cast<SCEVAddRecExpr>(TransformForPostIncUse(Normalize, S, 0, 0, 1167448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman Loops, SE, *SE.DT)); 1168a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1169a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1170a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec start. 1171a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Start = Normalized->getStart(); 1172a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopOffset = 0; 1173dc0e8fb9f9512622f55f73e1a434caa5c0915694Dan Gohman if (!SE.properlyDominates(Start, L->getHeader())) { 1174a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopOffset = Start; 1175deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Start = SE.getConstant(Normalized->getType(), 0); 11763228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized = cast<SCEVAddRecExpr>( 11773228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SE.getAddRecExpr(Start, Normalized->getStepRecurrence(SE), 11783228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized->getLoop(), 11793228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: Normalized->getNoWrapFlags(FlagNW) 11803228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1181a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1182a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1183a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Strip off any non-loop-dominating component from the addrec step. 1184a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *Step = Normalized->getStepRecurrence(SE); 1185a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *PostLoopScale = 0; 1186dc0e8fb9f9512622f55f73e1a434caa5c0915694Dan Gohman if (!SE.dominates(Step, L->getHeader())) { 1187a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PostLoopScale = Step; 1188deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman Step = SE.getConstant(Normalized->getType(), 1); 1189a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Normalized = 1190a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start, Step, 11913228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Normalized->getLoop(), 11923228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: Normalized 11933228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // ->getNoWrapFlags(FlagNW) 11943228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1195a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1196a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1197a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Expand the core addrec. If we need post-loop scaling, force it to 1198a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // expand to an integer type to avoid the need for additional casting. 1199db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ExpandTy = PostLoopScale ? IntTy : STy; 1200a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman PHINode *PN = getAddRecExprPHILiterally(Normalized, L, ExpandTy, IntTy); 1201a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 12023f46a3abeedba8d517b4182de34c821d752db058Dan Gohman // Accommodate post-inc mode, if necessary. 1203a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Value *Result; 1204448db1cdef5872713ef77beffacf502ae3450cd7Dan Gohman if (!PostIncLoops.count(L)) 1205a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN; 1206a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman else { 1207a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // In PostInc mode, use the post-incremented value. 1208a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman BasicBlock *LatchBlock = L->getLoopLatch(); 1209a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman assert(LatchBlock && "PostInc mode requires a unique loop latch!"); 1210a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = PN->getIncomingValueForBlock(LatchBlock); 121148ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick 121248ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // For an expansion to use the postinc form, the client must call 121348ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // expandCodeFor with an InsertPoint that is either outside the PostIncLoop 121448ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // or dominated by IVIncInsertPos. 1215553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (isa<Instruction>(Result) 1216553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick && !SE.DT->dominates(cast<Instruction>(Result), 1217553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Builder.GetInsertPoint())) { 1218553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // The induction variable's postinc expansion does not dominate this use. 1219553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // IVUsers tries to prevent this case, so it is rare. However, it can 1220553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // happen when an IVUser outside the loop is not dominated by the latch 1221553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // block. Adjusting IVIncInsertPos before expansion begins cannot handle 1222553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // all cases. Consider a phi outide whose operand is replaced during 1223553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // expansion with the value of the postinc user. Without fundamentally 1224553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // changing the way postinc users are tracked, the only remedy is 1225553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // inserting an extra IV increment. StepV might fold into PostLoopOffset, 1226553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // but hopefully expandCodeFor handles that. 1227553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick bool useSubtract = 1228f8fd841a4bb7a59f81cf4642169e8251e039acfeAndrew Trick !ExpandTy->isPointerTy() && Step->isNonConstantNegative(); 1229553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick if (useSubtract) 1230553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Step = SE.getNegativeSCEV(Step); 1231553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Expand the step somewhere that dominates the loop header. 1232553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1233553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1234553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Value *StepV = expandCodeFor(Step, IntTy, L->getHeader()->begin()); 1235553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // Restore the insertion point to the place where the caller has 1236553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick // determined dominates all uses. 1237553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1238553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick Result = expandIVInc(PN, StepV, L, ExpandTy, IntTy, useSubtract); 1239553fe05f236f46fe27b7fcfa822b06367d50183eAndrew Trick } 1240a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1241a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1242a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating scale. 1243a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopScale) { 12440a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1245a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateMul(Result, 1246a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopScale, IntTy)); 1247a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1248a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1249a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1250a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman // Re-apply any non-loop-dominating offset. 1251a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (PostLoopOffset) { 1252db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (PointerType *PTy = dyn_cast<PointerType>(ExpandTy)) { 1253a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman const SCEV *const OffsetArray[1] = { PostLoopOffset }; 1254a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = expandAddToGEP(OffsetArray, OffsetArray+1, PTy, IntTy, Result); 1255a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } else { 12560a799ab15801d4ebf68eeb151d6375a799c87d9aDan Gohman Result = InsertNoopCastOfTo(Result, IntTy); 1257a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman Result = Builder.CreateAdd(Result, 1258a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman expandCodeFor(PostLoopOffset, IntTy)); 1259a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Result); 1260a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1261a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman } 1262a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1263a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman return Result; 1264a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman} 1265a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1266890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { 1267a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman if (!CanonicalMode) return expandAddRecExprLiterally(S); 1268a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman 1269db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 127036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Loop *L = S->getLoop(); 127136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 12724d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // First check for an existing canonical IV in a suitable type. 12734d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman PHINode *CanonicalIV = 0; 12744d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (PHINode *PN = L->getCanonicalInductionVariable()) 1275133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman if (SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty)) 12764d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman CanonicalIV = PN; 12774d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 12784d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Rewrite an AddRec in terms of the canonical induction variable, if 12794d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // its type is more narrow. 12804d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (CanonicalIV && 12814d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(CanonicalIV->getType()) > 12824d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman SE.getTypeSizeInBits(Ty)) { 1283f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->getNumOperands()); 1284f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman for (unsigned i = 0, e = S->getNumOperands(); i != e; ++i) 1285f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman NewOps[i] = SE.getAnyExtendExpr(S->op_begin()[i], CanonicalIV->getType()); 12863228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick Value *V = expand(SE.getAddRecExpr(NewOps, S->getLoop(), 12873228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: S->getNoWrapFlags(FlagNW) 12883228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagAnyWrap)); 1289267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1290267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 12914d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman BasicBlock::iterator NewInsertPt = 12927896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner llvm::next(BasicBlock::iterator(cast<Instruction>(V))); 1293a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling while (isa<PHINode>(NewInsertPt) || isa<DbgInfoIntrinsic>(NewInsertPt) || 1294a4c86ab073d4b7a36477fc7c54c9d52499f04586Bill Wendling isa<LandingPadInst>(NewInsertPt)) 129508f55d02da2cd24f3b4297259ef6429b8bf1ef97Jim Grosbach ++NewInsertPt; 12964d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), 0, 12974d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewInsertPt); 1298455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 12994d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman return V; 13004d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman } 13014d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 130236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {X,+,F} --> X + {0,+,F} 1303cfeb6a450632f2a6cd05302633c8c2b8c90cfdfdDan Gohman if (!S->getStart()->isZero()) { 1304f9e64729afec646fe93b51417e66e552e8e630a4Dan Gohman SmallVector<const SCEV *, 4> NewOps(S->op_begin(), S->op_end()); 1305deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman NewOps[0] = SE.getConstant(Ty, 0); 13063228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // FIXME: can use S->getNoWrapFlags() 13073228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick const SCEV *Rest = SE.getAddRecExpr(NewOps, L, SCEV::FlagAnyWrap); 1308453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 1309453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the 1310453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman // comments on expandAddToGEP for details. 1311c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *Base = S->getStart(); 1312c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman const SCEV *RestArray[1] = { Rest }; 1313c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Dig into the expression to find the pointer base for a GEP. 1314c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman ExposePointerBase(Base, RestArray[0], SE); 1315c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // If we found a pointer, expand the AddRec with a GEP. 1316db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (PointerType *PTy = dyn_cast<PointerType>(Base->getType())) { 1317c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // Make sure the Base isn't something exotic, such as a multiplied 1318c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // or divided pointer value. In those cases, the result type isn't 1319c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman // actually a pointer type. 1320c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman if (!isa<SCEVMulExpr>(Base) && !isa<SCEVUDivExpr>(Base)) { 1321c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman Value *StartV = expand(Base); 1322c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman assert(StartV->getType() == PTy && "Pointer type mismatch for GEP!"); 1323c40f17b08774c2dcc5787fd83241e3c64ba82974Dan Gohman return expandAddToGEP(RestArray, RestArray+1, PTy, Ty, StartV); 1324453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1325453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman } 1326453aa4fbf1083cc7f646a0ac21e2bcc384a91ae9Dan Gohman 132740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Just do a normal add. Pre-expand the operands to suppress folding. 132840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return expand(SE.getAddExpr(SE.getUnknown(expand(S->getStart())), 132940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getUnknown(expand(Rest)))); 133036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 133136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13326ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // If we don't yet have a canonical IV, create one. 13336ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (!CanonicalIV) { 133436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Create and insert the PHI node for the induction variable in the 133536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // specified loop. 133636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman BasicBlock *Header = L->getHeader(); 1337d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad pred_iterator HPB = pred_begin(Header), HPE = pred_end(Header); 13383ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad CanonicalIV = PHINode::Create(Ty, std::distance(HPB, HPE), "indvar", 13393ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad Header->begin()); 13406ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman rememberInstruction(CanonicalIV); 134136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1342eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Constant *One = ConstantInt::get(Ty, 1); 1343d8b4fb4aab4d6fedb2b14bed1b846451b17bde7cJay Foad for (pred_iterator HPI = HPB; HPI != HPE; ++HPI) { 13447656018c2268285907cfdc106071462a01a73878Gabor Greif BasicBlock *HP = *HPI; 13457656018c2268285907cfdc106071462a01a73878Gabor Greif if (L->contains(HP)) { 13463abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // Insert a unit add instruction right before the terminator 13473abf905b50f33340ae81913da81b0eda96fa4616Dan Gohman // corresponding to the back-edge. 13486ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman Instruction *Add = BinaryOperator::CreateAdd(CanonicalIV, One, 13496ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "indvar.next", 13506ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman HP->getTerminator()); 1351df3ad6697bb849e514c0881ca8700ea36678cbdaDevang Patel Add->setDebugLoc(HP->getTerminator()->getDebugLoc()); 1352a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Add); 13536ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Add, HP); 135483d577490b1473213b6973236110c28e59127956Dan Gohman } else { 13556ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->addIncoming(Constant::getNullValue(Ty), HP); 135683d577490b1473213b6973236110c28e59127956Dan Gohman } 13577656018c2268285907cfdc106071462a01a73878Gabor Greif } 135836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 135936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13606ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman // {0,+,1} --> Insert a canonical induction variable into the loop! 13616ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman if (S->isAffine() && S->getOperand(1)->isOne()) { 13626ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) && 13636ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "IVs with types different from the canonical IV should " 13646ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman "already have been handled!"); 13656ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman return CanonicalIV; 13666ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman } 13676ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman 13684d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // {0,+,F} --> {0,+,1} * F 136936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 1370df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If this is a simple linear addrec, emit it now as a special case. 137140a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (S->isAffine()) // {0,+,F} --> i*F 137240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return 137340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman expand(SE.getTruncateOrNoop( 13746ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman SE.getMulExpr(SE.getUnknown(CanonicalIV), 137540a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman SE.getNoopOrAnyExtend(S->getOperand(1), 13766ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman CanonicalIV->getType())), 137740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman Ty)); 137836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 137936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // If this is a chain of recurrences, turn it into a closed form, using the 138036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // folders, then expandCodeFor the closed form. This allows the folders to 138136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // simplify the expression without having to build a bunch of special code 138236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // into this folder. 13836ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *IH = SE.getUnknown(CanonicalIV); // Get I as a "symbolic" SCEV. 138436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13854d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Promote S up to the canonical IV type, if the cast is foldable. 13860bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *NewS = S; 13876ebfd72f37325a1ebceb53e5ecad524d359d8d0bDan Gohman const SCEV *Ext = SE.getNoopOrAnyExtend(S, CanonicalIV->getType()); 13884d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman if (isa<SCEVAddRecExpr>(Ext)) 13894d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman NewS = Ext; 13904d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman 13910bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE); 1392e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; 139336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 13944d8414f42033a5e744e8e60d2ca188b424c76168Dan Gohman // Truncate the result down to the original type, if needed. 13950bba49cebc50c7bd4662a4807bcb3ee7f42cb470Dan Gohman const SCEV *T = SE.getTruncateOrNoop(V, Ty); 1396469f3cdc13851914f3a766cbd8f701cf8431cacaDan Gohman return expand(T); 139736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 139896fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 1399890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitTruncateExpr(const SCEVTruncateExpr *S) { 1400db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 140192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 140292fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1403a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateTrunc(V, Ty); 1404a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1405cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 140611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 140711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1408890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitZeroExtendExpr(const SCEVZeroExtendExpr *S) { 1409db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 141092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 141192fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1412a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateZExt(V, Ty); 1413a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1414cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 141511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 141611f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1417890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) { 1418db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = SE.getEffectiveSCEVType(S->getType()); 141992fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *V = expandCodeFor(S->getOperand(), 142092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman SE.getEffectiveSCEVType(S->getOperand()->getType())); 1421a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *I = Builder.CreateSExt(V, Ty); 1422a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(I); 1423cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman return I; 142411f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 142511f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1426890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { 14270196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 1428db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = LHS->getType(); 14290196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 14300196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 14310196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 14320196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 14330196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 14340196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 14350196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 143692fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1437a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *ICmp = Builder.CreateICmpSGT(LHS, RHS); 1438a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1439267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "smax"); 1440a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1441cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 1442c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky } 14430196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 14440196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 14450196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 14460196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 1447c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky return LHS; 1448c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky} 1449c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky 1450890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { 14510196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); 1452db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = LHS->getType(); 14530196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 14540196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, do the 14550196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // rest of the comparisons as integer. 14560196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (S->getOperand(i)->getType() != Ty) { 14570196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman Ty = SE.getEffectiveSCEVType(Ty); 14580196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 14590196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman } 146092fcdcac543653a62949fe9e5a7bd008500c1380Dan Gohman Value *RHS = expandCodeFor(S->getOperand(i), Ty); 1461a9390a4d5f5d568059a80970d22194b165d097a7Benjamin Kramer Value *ICmp = Builder.CreateICmpUGT(LHS, RHS); 1462a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(ICmp); 1463267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Value *Sel = Builder.CreateSelect(ICmp, LHS, RHS, "umax"); 1464a10756ee657a4d43a48cca5c166919093930ed6bDan Gohman rememberInstruction(Sel); 1465cf5ab820227dedd77fb91d0904b6dc3694a7c196Dan Gohman LHS = Sel; 14663e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky } 14670196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // In the case of mixed integer and pointer types, cast the 14680196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman // final result back to the pointer type. 14690196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman if (LHS->getType() != S->getType()) 14700196dc5733bf3c6a71f7de1f631f2c43e5809fd9Dan Gohman LHS = InsertNoopCastOfTo(LHS, S->getType()); 14713e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky return LHS; 14723e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky} 14733e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky 1474db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::expandCodeFor(const SCEV *SH, Type *Ty, 1475b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick Instruction *IP) { 14766c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman Builder.SetInsertPoint(IP->getParent(), IP); 14776c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman return expandCodeFor(SH, Ty); 14786c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman} 14796c7ed6b54949949806797bafdf545fbfecb2cef5Dan Gohman 1480db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris LattnerValue *SCEVExpander::expandCodeFor(const SCEV *SH, Type *Ty) { 148111f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman // Expand the code for this SCEV. 14822d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *V = expand(SH); 14835be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman if (Ty) { 14845be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman assert(SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(SH->getType()) && 14855be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman "non-trivial casts should be done with the SCEVs directly!"); 14865be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman V = InsertNoopCastOfTo(V, Ty); 14875be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman } 14885be18e84766fb495b0bde3c8244c1df459a18683Dan Gohman return V; 148911f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 149011f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 1491890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::expand(const SCEV *S) { 149240a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // Compute an insertion point for this SCEV object. Hoist the instructions 149340a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // as far out in the loop nest as possible. 1494267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Instruction *InsertPt = Builder.GetInsertPoint(); 1495267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman for (Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock()); ; 149640a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman L = L->getParentLoop()) 149717ead4ff4baceb2c5503f233d0288d363ae44165Dan Gohman if (SE.isLoopInvariant(S, L)) { 149840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman if (!L) break; 1499e059ee832ca36d65a5fb87b0ac5bcdb0490b15cbDan Gohman if (BasicBlock *Preheader = L->getLoopPreheader()) 150040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman InsertPt = Preheader->getTerminator(); 15010f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick else { 15020f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick // LSR sets the insertion point for AddRec start/step values to the 15030f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick // block start to simplify value reuse, even though it's an invalid 15040f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick // position. SCEVExpander must correct for this in all cases. 15050f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick InsertPt = L->getHeader()->getFirstInsertionPt(); 15060f8cd56bfdd32af4edb253654db02fb3143b25a8Andrew Trick } 150740a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } else { 150840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // If the SCEV is computable at this level, insert it into the header 150940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // after the PHIs (and after any other instructions that we've inserted 151040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman // there) so that it is guaranteed to dominate any user inside the loop. 15115b6f42f57e730c2d968c313a27fa505a3c3e5efaBill Wendling if (L && SE.hasComputableLoopEvolution(S, L) && !PostIncLoops.count(L)) 15125b6f42f57e730c2d968c313a27fa505a3c3e5efaBill Wendling InsertPt = L->getHeader()->getFirstInsertionPt(); 1513b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick while (InsertPt != Builder.GetInsertPoint() 1514b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick && (isInsertedInstruction(InsertPt) 1515b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick || isa<DbgInfoIntrinsic>(InsertPt))) { 15167896c9f436a4eda5ec15e882a7505ba482a2fcd0Chris Lattner InsertPt = llvm::next(BasicBlock::iterator(InsertPt)); 1517b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick } 151840a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman break; 151940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman } 152040a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1521667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Check to see if we already expanded this here. 1522667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman std::map<std::pair<const SCEV *, Instruction *>, 1523667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman AssertingVH<Value> >::iterator I = 1524667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman InsertedExpressions.find(std::make_pair(S, InsertPt)); 1525267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (I != InsertedExpressions.end()) 1526667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman return I->second; 1527267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman 1528267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1529267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 1530267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman Builder.SetInsertPoint(InsertPt->getParent(), InsertPt); 1531667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1532667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Expand the expression into instructions. 153396fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov Value *V = visit(S); 153440a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman 1535667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman // Remember the expanded value for this SCEV at this location. 153648ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // 153748ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // This is independent of PostIncLoops. The mapped value simply materializes 153848ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // the expression at this insertion point. If the mapped value happened to be 153948ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // a postinc expansion, it could be reused by a non postinc user, but only if 154048ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick // its insertion point was already at the head of the loop. 154148ba0e45ed68689ce7b384578e6272410e4e23feAndrew Trick InsertedExpressions[std::make_pair(S, InsertPt)] = V; 1542667d787c0a21cf3f5dfcde03ca471162ba35b614Dan Gohman 1543455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 154496fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return V; 154596fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov} 15461d09de3eca23267855e28297fcb40de3632ea47bDan Gohman 15471d826a76f591afea445489b9a5485c345e66bf87Dan Gohmanvoid SCEVExpander::rememberInstruction(Value *I) { 154825fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman if (!PostIncLoops.empty()) 154925fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman InsertedPostIncValues.insert(I); 155025fcaff409f5c4c6da08f148ffb9404a71e8e4a7Dan Gohman else 15511d826a76f591afea445489b9a5485c345e66bf87Dan Gohman InsertedValues.insert(I); 15521d826a76f591afea445489b9a5485c345e66bf87Dan Gohman} 15531d826a76f591afea445489b9a5485c345e66bf87Dan Gohman 1554455985501381777db03534c925a35e261e356395Dan Gohmanvoid SCEVExpander::restoreInsertPoint(BasicBlock *BB, BasicBlock::iterator I) { 1555455985501381777db03534c925a35e261e356395Dan Gohman Builder.SetInsertPoint(BB, I); 1556455985501381777db03534c925a35e261e356395Dan Gohman} 1557455985501381777db03534c925a35e261e356395Dan Gohman 15581d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// getOrInsertCanonicalInductionVariable - This method returns the 15591d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// canonical induction variable of the specified type for the specified 15601d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// loop (inserting one if there is none). A canonical induction variable 15611d09de3eca23267855e28297fcb40de3632ea47bDan Gohman/// starts at zero and steps by one on each iteration. 15627c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan GohmanPHINode * 15631d09de3eca23267855e28297fcb40de3632ea47bDan GohmanSCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L, 1564db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty) { 1565b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands assert(Ty->isIntegerTy() && "Can only insert integer induction variables!"); 1566133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1567133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Build a SCEV for {0,+,1}<L>. 15683228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick // Conservatively use FlagAnyWrap for now. 1569deff621abdd48bd70434bd4d7ef30f08ddba1cd8Dan Gohman const SCEV *H = SE.getAddRecExpr(SE.getConstant(Ty, 0), 15703228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SE.getConstant(Ty, 1), L, SCEV::FlagAnyWrap); 1571133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 1572133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman // Emit code for it. 1573267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); 1574267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); 15757c58dbd88c36c5d6c411ea6c046ddcff4c5841e9Dan Gohman PHINode *V = cast<PHINode>(expandCodeFor(H, 0, L->getHeader()->begin())); 1576267a385342f2e7388f178b327dd87c5f29afd51bDan Gohman if (SaveInsertBB) 1577455985501381777db03534c925a35e261e356395Dan Gohman restoreInsertPoint(SaveInsertBB, SaveInsertPt); 1578133e295b363c89b6a3da7aba3ac5ae6332429e46Dan Gohman 157940a5a1b39ee1cd40ff9d04740386b667fb27b340Dan Gohman return V; 15801d09de3eca23267855e28297fcb40de3632ea47bDan Gohman} 1581204494149b6f846e8f173f525b129f5508076049Andrew Trick 1582139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trick/// Sort values by integer width for replaceCongruentIVs. 1583139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trickstatic bool width_descending(Value *lhs, Value *rhs) { 1584ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Put pointers at the back and make sure pointer < pointer = false. 1585ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (!lhs->getType()->isIntegerTy() || !rhs->getType()->isIntegerTy()) 1586ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick return rhs->getType()->isIntegerTy() && !lhs->getType()->isIntegerTy(); 1587ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick return rhs->getType()->getPrimitiveSizeInBits() 1588ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick < lhs->getType()->getPrimitiveSizeInBits(); 1589ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick} 1590ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick 1591204494149b6f846e8f173f525b129f5508076049Andrew Trick/// replaceCongruentIVs - Check for congruent phis in this loop header and 1592204494149b6f846e8f173f525b129f5508076049Andrew Trick/// replace them with their most canonical representative. Return the number of 1593204494149b6f846e8f173f525b129f5508076049Andrew Trick/// phis eliminated. 1594204494149b6f846e8f173f525b129f5508076049Andrew Trick/// 1595204494149b6f846e8f173f525b129f5508076049Andrew Trick/// This does not depend on any SCEVExpander state but should be used in 1596204494149b6f846e8f173f525b129f5508076049Andrew Trick/// the same context that SCEVExpander is used. 1597204494149b6f846e8f173f525b129f5508076049Andrew Trickunsigned SCEVExpander::replaceCongruentIVs(Loop *L, const DominatorTree *DT, 1598ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick SmallVectorImpl<WeakVH> &DeadInsts, 1599ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick const TargetLowering *TLI) { 1600ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Find integer phis in order of increasing width. 1601ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick SmallVector<PHINode*, 8> Phis; 1602ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick for (BasicBlock::iterator I = L->getHeader()->begin(); 1603ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick PHINode *Phi = dyn_cast<PHINode>(I); ++I) { 1604ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Phis.push_back(Phi); 1605ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1606ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (TLI) 1607ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick std::sort(Phis.begin(), Phis.end(), width_descending); 1608ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick 1609204494149b6f846e8f173f525b129f5508076049Andrew Trick unsigned NumElim = 0; 1610204494149b6f846e8f173f525b129f5508076049Andrew Trick DenseMap<const SCEV *, PHINode *> ExprToIVMap; 1611ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Process phis from wide to narrow. Mapping wide phis to the their truncation 1612ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // so narrow phis can reuse them. 1613ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick for (SmallVectorImpl<PHINode*>::const_iterator PIter = Phis.begin(), 1614ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick PEnd = Phis.end(); PIter != PEnd; ++PIter) { 1615ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick PHINode *Phi = *PIter; 1616ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick 1617204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!SE.isSCEVable(Phi->getType())) 1618204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1619204494149b6f846e8f173f525b129f5508076049Andrew Trick 1620204494149b6f846e8f173f525b129f5508076049Andrew Trick PHINode *&OrigPhiRef = ExprToIVMap[SE.getSCEV(Phi)]; 1621204494149b6f846e8f173f525b129f5508076049Andrew Trick if (!OrigPhiRef) { 1622204494149b6f846e8f173f525b129f5508076049Andrew Trick OrigPhiRef = Phi; 1623ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (Phi->getType()->isIntegerTy() && TLI 1624ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick && TLI->isTruncateFree(Phi->getType(), Phis.back()->getType())) { 1625ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // This phi can be freely truncated to the narrowest phi type. Map the 1626ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // truncated expression to it so it will be reused for narrow types. 1627ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick const SCEV *TruncExpr = 1628ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick SE.getTruncateExpr(SE.getSCEV(Phi), Phis.back()->getType()); 1629ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick ExprToIVMap[TruncExpr] = Phi; 1630ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1631204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1632204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1633204494149b6f846e8f173f525b129f5508076049Andrew Trick 1634ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // Replacing a pointer phi with an integer phi or vice-versa doesn't make 1635ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // sense. 1636ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigPhiRef->getType()->isPointerTy() != Phi->getType()->isPointerTy()) 1637204494149b6f846e8f173f525b129f5508076049Andrew Trick continue; 1638204494149b6f846e8f173f525b129f5508076049Andrew Trick 1639204494149b6f846e8f173f525b129f5508076049Andrew Trick if (BasicBlock *LatchBlock = L->getLoopLatch()) { 1640204494149b6f846e8f173f525b129f5508076049Andrew Trick Instruction *OrigInc = 1641204494149b6f846e8f173f525b129f5508076049Andrew Trick cast<Instruction>(OrigPhiRef->getIncomingValueForBlock(LatchBlock)); 1642204494149b6f846e8f173f525b129f5508076049Andrew Trick Instruction *IsomorphicInc = 1643204494149b6f846e8f173f525b129f5508076049Andrew Trick cast<Instruction>(Phi->getIncomingValueForBlock(LatchBlock)); 1644204494149b6f846e8f173f525b129f5508076049Andrew Trick 1645ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick // If this phi has the same width but is more canonical, replace the 1646b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // original with it. As part of the "more canonical" determination, 1647b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick // respect a prior decision to use an IV chain. 1648ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigPhiRef->getType() == Phi->getType() 1649b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick && !(ChainedPhis.count(Phi) 1650b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick || isExpandedAddRecExprPHI(OrigPhiRef, OrigInc, L)) 1651b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick && (ChainedPhis.count(Phi) 1652b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick || isExpandedAddRecExprPHI(Phi, IsomorphicInc, L))) { 1653204494149b6f846e8f173f525b129f5508076049Andrew Trick std::swap(OrigPhiRef, Phi); 1654204494149b6f846e8f173f525b129f5508076049Andrew Trick std::swap(OrigInc, IsomorphicInc); 1655204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1656204494149b6f846e8f173f525b129f5508076049Andrew Trick // Replacing the congruent phi is sufficient because acyclic redundancy 1657204494149b6f846e8f173f525b129f5508076049Andrew Trick // elimination, CSE/GVN, should handle the rest. However, once SCEV proves 1658204494149b6f846e8f173f525b129f5508076049Andrew Trick // that a phi is congruent, it's often the head of an IV user cycle that 1659139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trick // is isomorphic with the original phi. It's worth eagerly cleaning up the 1660139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trick // common case of a single IV increment so that DeleteDeadPHIs can remove 1661139f333f88fb9e0c39dfa3b56fd2a26b33837b70Andrew Trick // cycles that had postinc uses. 1662ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick const SCEV *TruncExpr = SE.getTruncateOrNoop(SE.getSCEV(OrigInc), 1663ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick IsomorphicInc->getType()); 1664ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigInc != IsomorphicInc 166564925c55c65f9345a69fb67db07aa62cfb723577Andrew Trick && TruncExpr == SE.getSCEV(IsomorphicInc) 1666b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick && ((isa<PHINode>(OrigInc) && isa<PHINode>(IsomorphicInc)) 1667b5c26ef9da16052597d59a412eaae32098aa1be0Andrew Trick || hoistIVInc(OrigInc, IsomorphicInc))) { 1668204494149b6f846e8f173f525b129f5508076049Andrew Trick DEBUG_WITH_TYPE(DebugType, dbgs() 1669204494149b6f846e8f173f525b129f5508076049Andrew Trick << "INDVARS: Eliminated congruent iv.inc: " 1670204494149b6f846e8f173f525b129f5508076049Andrew Trick << *IsomorphicInc << '\n'); 1671ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Value *NewInc = OrigInc; 1672ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigInc->getType() != IsomorphicInc->getType()) { 1673dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick Instruction *IP = isa<PHINode>(OrigInc) 1674dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick ? (Instruction*)L->getHeader()->getFirstInsertionPt() 1675dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick : OrigInc->getNextNode(); 1676dd1f22f25d8496b10cfddedb63d674dd39897bb0Andrew Trick IRBuilder<> Builder(IP); 1677ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Builder.SetCurrentDebugLocation(IsomorphicInc->getDebugLoc()); 1678ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick NewInc = Builder. 1679ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick CreateTruncOrBitCast(OrigInc, IsomorphicInc->getType(), IVName); 1680ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1681ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick IsomorphicInc->replaceAllUsesWith(NewInc); 1682204494149b6f846e8f173f525b129f5508076049Andrew Trick DeadInsts.push_back(IsomorphicInc); 1683204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1684204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1685204494149b6f846e8f173f525b129f5508076049Andrew Trick DEBUG_WITH_TYPE(DebugType, dbgs() 1686204494149b6f846e8f173f525b129f5508076049Andrew Trick << "INDVARS: Eliminated congruent iv: " << *Phi << '\n'); 1687204494149b6f846e8f173f525b129f5508076049Andrew Trick ++NumElim; 1688ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Value *NewIV = OrigPhiRef; 1689ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick if (OrigPhiRef->getType() != Phi->getType()) { 1690ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick IRBuilder<> Builder(L->getHeader()->getFirstInsertionPt()); 1691ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Builder.SetCurrentDebugLocation(Phi->getDebugLoc()); 1692ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick NewIV = Builder.CreateTruncOrBitCast(OrigPhiRef, Phi->getType(), IVName); 1693ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick } 1694ee98aa87434d9d49a8e4dab41d873888ac9c4805Andrew Trick Phi->replaceAllUsesWith(NewIV); 1695204494149b6f846e8f173f525b129f5508076049Andrew Trick DeadInsts.push_back(Phi); 1696204494149b6f846e8f173f525b129f5508076049Andrew Trick } 1697204494149b6f846e8f173f525b129f5508076049Andrew Trick return NumElim; 1698204494149b6f846e8f173f525b129f5508076049Andrew Trick} 1699