ScalarEvolutionExpander.cpp revision aabb04f52714ceb271dba7da18f757a4365bb4ac
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" 1836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begemanusing namespace llvm; 1936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 20ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner/// InsertCastOfTo - Insert a cast of V to the specified type, doing what 21ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner/// we can to share the casts. 223ba68b9eef2851dae8a9d1b18928c6fa2e3c5f87Reid SpencerValue *SCEVExpander::InsertCastOfTo(Instruction::CastOps opcode, Value *V, 233ba68b9eef2851dae8a9d1b18928c6fa2e3c5f87Reid Spencer const Type *Ty) { 242d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman // Short-circuit unnecessary bitcasts. 252d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman if (opcode == Instruction::BitCast && V->getType() == Ty) 262d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman return V; 272d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 28f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman // Short-circuit unnecessary inttoptr<->ptrtoint casts. 29af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if ((opcode == Instruction::PtrToInt || opcode == Instruction::IntToPtr) && 30af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) 31af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if (CastInst *CI = dyn_cast<CastInst>(V)) 32af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman if ((CI->getOpcode() == Instruction::PtrToInt || 33af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman CI->getOpcode() == Instruction::IntToPtr) && 34af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getType()) == 35af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman SE.getTypeSizeInBits(CI->getOperand(0)->getType())) 36af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return CI->getOperand(0); 37f04fa483b83227c570bc58e1684ea096430a6697Dan Gohman 38ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner // FIXME: keep track of the cast instruction. 39ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 40d977d8651a5cd26a3e1088267f31cade405f2adfReid Spencer return ConstantExpr::getCast(opcode, C, Ty); 41ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 42ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (Argument *A = dyn_cast<Argument>(V)) { 43ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner // Check to see if there is already a cast! 44ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner for (Value::use_iterator UI = A->use_begin(), E = A->use_end(); 45ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner UI != E; ++UI) { 46ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if ((*UI)->getType() == Ty) 473913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (CastInst *CI = dyn_cast<CastInst>(cast<Instruction>(*UI))) 483913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (CI->getOpcode() == opcode) { 493913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz // If the cast isn't the first instruction of the function, move it. 503913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (BasicBlock::iterator(CI) != 513913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz A->getParent()->getEntryBlock().begin()) { 52aabb04f52714ceb271dba7da18f757a4365bb4acDan Gohman // If the CastInst is the insert point, change the insert point. 53aabb04f52714ceb271dba7da18f757a4365bb4acDan Gohman if (CI == InsertPt) ++InsertPt; 54aabb04f52714ceb271dba7da18f757a4365bb4acDan Gohman // Splice the cast at the beginning of the entry block. 553913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz CI->moveBefore(A->getParent()->getEntryBlock().begin()); 563913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz } 573913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz return CI; 58ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 59ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 607cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif return CastInst::Create(opcode, V, Ty, V->getName(), 61d977d8651a5cd26a3e1088267f31cade405f2adfReid Spencer A->getParent()->getEntryBlock().begin()); 62ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 633913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 64ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner Instruction *I = cast<Instruction>(V); 653913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz 66ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner // Check to see if there is already a cast. If there is, use it. 67ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); 68ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner UI != E; ++UI) { 69ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if ((*UI)->getType() == Ty) 703913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (CastInst *CI = dyn_cast<CastInst>(cast<Instruction>(*UI))) 713913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (CI->getOpcode() == opcode) { 723913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz BasicBlock::iterator It = I; ++It; 733913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (isa<InvokeInst>(I)) 743913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz It = cast<InvokeInst>(I)->getNormalDest()->begin(); 753913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz while (isa<PHINode>(It)) ++It; 763913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz if (It != BasicBlock::iterator(CI)) { 77aabb04f52714ceb271dba7da18f757a4365bb4acDan Gohman // If the CastInst is the insert point, change the insert point. 78aabb04f52714ceb271dba7da18f757a4365bb4acDan Gohman if (CI == InsertPt) ++InsertPt; 793913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz // Splice the cast immediately after the operand in question. 803913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz CI->moveBefore(It); 813913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz } 823913187bf6135e6a71260c65eed664095c8f9ce9Wojciech Matyjewicz return CI; 83ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 84ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner } 85ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner BasicBlock::iterator IP = I; ++IP; 86ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(I)) 87ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner IP = II->getNormalDest()->begin(); 88ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner while (isa<PHINode>(IP)) ++IP; 897cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif return CastInst::Create(opcode, V, Ty, V->getName(), IP); 90ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner} 91ca1a4bebb3928ba18fb8751e2f0c0f88fad54cfdChris Lattner 92af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman/// InsertNoopCastOfTo - Insert a cast of V to the specified type, 93af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman/// which must be possible with a noop cast. 94af79fb5f47b0088c6a8973a7fdbaea96973a429dDan GohmanValue *SCEVExpander::InsertNoopCastOfTo(Value *V, const Type *Ty) { 95af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman Instruction::CastOps Op = CastInst::getCastOpcode(V, false, Ty, false); 96af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman assert((Op == Instruction::BitCast || 97af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman Op == Instruction::Instruction::PtrToInt || 98af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman Op == Instruction::Instruction::IntToPtr) && 99af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman "InsertNoopCastOfTo cannot perform non-noop casts!"); 100af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman assert(SE.getTypeSizeInBits(V->getType()) == SE.getTypeSizeInBits(Ty) && 101af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman "InsertNoopCastOfTo cannot change sizes!"); 102af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return InsertCastOfTo(Op, V, Ty); 103af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman} 104af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman 1057fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// InsertBinop - Insert the specified binary operator, doing a small amount 1067fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner/// of work to avoid inserting an obviously redundant operation. 1077fec90ebf4ebe7aa73a6dd7d275c255587c041adChris LattnerValue *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, Value *LHS, 1086cdc727f2d7f68734526ef078f4632798ad40791Dan Gohman Value *RHS, BasicBlock::iterator InsertPt) { 1090f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman // Fold a binop with constant operands. 1100f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CLHS = dyn_cast<Constant>(LHS)) 1110f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman if (Constant *CRHS = dyn_cast<Constant>(RHS)) 1120f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman return ConstantExpr::get(Opcode, CLHS, CRHS); 1130f0eb18addc94bf3d8179fbce162c8c4622b9866Dan Gohman 1147fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner // Do a quick scan to see if we have this binop nearby. If so, reuse it. 1157fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner unsigned ScanLimit = 6; 1168a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz BasicBlock::iterator BlockBegin = InsertPt->getParent()->begin(); 1178a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (InsertPt != BlockBegin) { 1188a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // Scanning starts from the last instruction before InsertPt. 1198a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz BasicBlock::iterator IP = InsertPt; 1208a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz --IP; 1218a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz for (; ScanLimit; --IP, --ScanLimit) { 1228a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(IP)) 1238a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (BinOp->getOpcode() == Opcode && BinOp->getOperand(0) == LHS && 1248a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz BinOp->getOperand(1) == RHS) 1258a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz return BinOp; 1268a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz if (IP == BlockBegin) break; 1278a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz } 1287fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner } 1298a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz 1308a08769bad43a22fae2845bb0ba0fd1266cd55c8Wojciech Matyjewicz // If we haven't found this binop, insert it. 1317cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif return BinaryOperator::Create(Opcode, LHS, RHS, "tmp", InsertPt); 1327fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner} 1337fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner 134890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { 135af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 136e24fa64d52330626553298f56ba5aa702624c282Dan Gohman Value *V = expand(S->getOperand(S->getNumOperands()-1)); 137af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman V = InsertNoopCastOfTo(V, Ty); 138e24fa64d52330626553298f56ba5aa702624c282Dan Gohman 139e24fa64d52330626553298f56ba5aa702624c282Dan Gohman // Emit a bunch of add instructions 1402d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman for (int i = S->getNumOperands()-2; i >= 0; --i) { 1412d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *W = expand(S->getOperand(i)); 142af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman W = InsertNoopCastOfTo(W, Ty); 1432d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman V = InsertBinop(Instruction::Add, V, W, InsertPt); 1442d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 145e24fa64d52330626553298f56ba5aa702624c282Dan Gohman return V; 146e24fa64d52330626553298f56ba5aa702624c282Dan Gohman} 147e24fa64d52330626553298f56ba5aa702624c282Dan Gohman 148890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) { 149af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 15036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman int FirstOp = 0; // Set if we should emit a subtract. 151890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getOperand(0))) 15236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (SC->getValue()->isAllOnesValue()) 15336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman FirstOp = 1; 15436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 15536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman int i = S->getNumOperands()-2; 156d19534add90a2a894af61523b830887097bb780bDan Gohman Value *V = expand(S->getOperand(i+1)); 157af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman V = InsertNoopCastOfTo(V, Ty); 15836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 15936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Emit a bunch of multiply instructions 1602d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman for (; i >= FirstOp; --i) { 1612d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *W = expand(S->getOperand(i)); 162af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman W = InsertNoopCastOfTo(W, Ty); 1632d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman V = InsertBinop(Instruction::Mul, V, W, InsertPt); 1642d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman } 1652d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 16636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // -1 * ... ---> 0 - ... 16736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (FirstOp == 1) 1682d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman V = InsertBinop(Instruction::Sub, Constant::getNullValue(Ty), V, InsertPt); 16936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman return V; 17036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 17136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 172890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) { 173af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 1742d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman 1756177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky Value *LHS = expand(S->getLHS()); 176af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 177890f92b744fb074465bc2b7006ee753a181f62a4Dan Gohman if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getRHS())) { 1786177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky const APInt &RHS = SC->getValue()->getValue(); 1796177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky if (RHS.isPowerOf2()) 1806177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky return InsertBinop(Instruction::LShr, LHS, 1812d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman ConstantInt::get(Ty, RHS.logBase2()), 1826177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky InsertPt); 1836177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky } 1846177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 1856177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky Value *RHS = expand(S->getRHS()); 186af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman RHS = InsertNoopCastOfTo(RHS, Ty); 1876177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky return InsertBinop(Instruction::UDiv, LHS, RHS, InsertPt); 1886177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky} 1896177fd4fcee4d82692c47e33754ffe285c38cc69Nick Lewycky 190890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { 191af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 19236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman const Loop *L = S->getLoop(); 19336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 19436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {X,+,F} --> X + {0,+,F} 195cfeb6a450632f2a6cd05302633c8c2b8c90cfdfdDan Gohman if (!S->getStart()->isZero()) { 196d19534add90a2a894af61523b830887097bb780bDan Gohman Value *Start = expand(S->getStart()); 197af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman Start = InsertNoopCastOfTo(Start, Ty); 19836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman std::vector<SCEVHandle> NewOps(S->op_begin(), S->op_end()); 199246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman NewOps[0] = SE.getIntegerSCEV(0, Ty); 200246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman Value *Rest = expand(SE.getAddRecExpr(NewOps, L)); 201af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman Rest = InsertNoopCastOfTo(Rest, Ty); 20236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 20336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // FIXME: look for an existing add to use. 2047fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner return InsertBinop(Instruction::Add, Rest, Start, InsertPt); 20536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 20636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 20736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // {0,+,1} --> Insert a canonical induction variable into the loop! 20817f1972c770dc18f5c7c3c95776b4d62ae9e121dDan Gohman if (S->isAffine() && 209246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman S->getOperand(1) == SE.getIntegerSCEV(1, Ty)) { 21036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Create and insert the PHI node for the induction variable in the 21136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // specified loop. 21236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman BasicBlock *Header = L->getHeader(); 213051a950000e21935165db56695e35bade668193bGabor Greif PHINode *PN = PHINode::Create(Ty, "indvar", Header->begin()); 21436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman PN->addIncoming(Constant::getNullValue(Ty), L->getLoopPreheader()); 21536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 21636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman pred_iterator HPI = pred_begin(Header); 21736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman assert(HPI != pred_end(Header) && "Loop with zero preds???"); 21836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (!L->contains(*HPI)) ++HPI; 21936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman assert(HPI != pred_end(Header) && L->contains(*HPI) && 22036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman "No backedge in loop?"); 22136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 22236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Insert a unit add instruction right before the terminator corresponding 22336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // to the back-edge. 22424d6da5fedcf39891f7d8c5b031c01324b3db545Reid Spencer Constant *One = ConstantInt::get(Ty, 1); 2257cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif Instruction *Add = BinaryOperator::CreateAdd(PN, One, "indvar.next", 22636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman (*HPI)->getTerminator()); 22736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 22836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman pred_iterator PI = pred_begin(Header); 22936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman if (*PI == L->getLoopPreheader()) 23036f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman ++PI; 23136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman PN->addIncoming(Add, *PI); 23236f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman return PN; 23336f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 23436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 23536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // Get the canonical induction variable I for this loop. 23636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman Value *I = getOrInsertCanonicalInductionVariable(L, Ty); 23736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 238df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If this is a simple linear addrec, emit it now as a special case. 23917f1972c770dc18f5c7c3c95776b4d62ae9e121dDan Gohman if (S->isAffine()) { // {0,+,F} --> i*F 240d19534add90a2a894af61523b830887097bb780bDan Gohman Value *F = expand(S->getOperand(1)); 241af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman F = InsertNoopCastOfTo(F, Ty); 242df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner 243df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // IF the step is by one, just return the inserted IV. 2446b6b6ef1677fa71b1072c2911b4c1f9524a558c9Zhou Sheng if (ConstantInt *CI = dyn_cast<ConstantInt>(F)) 2454d050d73210d15d8a86ee5967c417ddb5bee4543Reid Spencer if (CI->getValue() == 1) 246df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner return I; 247df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner 248df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If the insert point is directly inside of the loop, emit the multiply at 249df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // the insert point. Otherwise, L is a loop that is a parent of the insert 250df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // point loop. If we can, move the multiply to the outer most loop that it 251df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // is safe to be in. 2526cdc727f2d7f68734526ef078f4632798ad40791Dan Gohman BasicBlock::iterator MulInsertPt = getInsertionPoint(); 253df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner Loop *InsertPtLoop = LI.getLoopFor(MulInsertPt->getParent()); 254df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner if (InsertPtLoop != L && InsertPtLoop && 255df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner L->contains(InsertPtLoop->getHeader())) { 2565d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz do { 257df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner // If we cannot hoist the multiply out of this loop, don't. 258df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner if (!InsertPtLoop->isLoopInvariant(F)) break; 259df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner 2605d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz BasicBlock *InsertPtLoopPH = InsertPtLoop->getLoopPreheader(); 2615d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz 2625d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz // If this loop hasn't got a preheader, we aren't able to hoist the 2635d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz // multiply. 2645d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz if (!InsertPtLoopPH) 2655d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz break; 2665d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz 2675d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz // Otherwise, move the insert point to the preheader. 2685d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz MulInsertPt = InsertPtLoopPH->getTerminator(); 269df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner InsertPtLoop = InsertPtLoop->getParentLoop(); 2705d2bc857ec1ae11ec2ea85e596f3712d02fd2c2bWojciech Matyjewicz } while (InsertPtLoop != L); 271df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner } 272df14a04b5ccbbe6a46c2ccb93e27b12a36ff163eChris Lattner 2737fec90ebf4ebe7aa73a6dd7d275c255587c041adChris Lattner return InsertBinop(Instruction::Mul, I, F, MulInsertPt); 27436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman } 27536f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 27636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // If this is a chain of recurrences, turn it into a closed form, using the 27736f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // folders, then expandCodeFor the closed form. This allows the folders to 27836f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // simplify the expression without having to build a bunch of special code 27936f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman // into this folder. 280246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman SCEVHandle IH = SE.getUnknown(I); // Get I as a "symbolic" SCEV. 28136f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 282246b2564d3bbbafe06ebf6a67745cd24141b5cb4Dan Gohman SCEVHandle V = S->evaluateAtIteration(IH, SE); 283e81561909d128c6e2d8033cb5465a49b2596b26aBill Wendling //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; 28436f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman 285d19534add90a2a894af61523b830887097bb780bDan Gohman return expand(V); 28636f891bdf6cf38fcc655a0930ca18664e18518d4Nate Begeman} 28796fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 288890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitTruncateExpr(const SCEVTruncateExpr *S) { 289af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 29011f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman Value *V = expand(S->getOperand()); 291af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman V = InsertNoopCastOfTo(V, SE.getEffectiveSCEVType(V->getType())); 2926cdc727f2d7f68734526ef078f4632798ad40791Dan Gohman return new TruncInst(V, Ty, "tmp.", InsertPt); 29311f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 29411f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 295890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitZeroExtendExpr(const SCEVZeroExtendExpr *S) { 296af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 29711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman Value *V = expand(S->getOperand()); 298af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman V = InsertNoopCastOfTo(V, SE.getEffectiveSCEVType(V->getType())); 2996cdc727f2d7f68734526ef078f4632798ad40791Dan Gohman return new ZExtInst(V, Ty, "tmp.", InsertPt); 30011f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 30111f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 302890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) { 303af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 30411f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman Value *V = expand(S->getOperand()); 305af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman V = InsertNoopCastOfTo(V, SE.getEffectiveSCEVType(V->getType())); 3066cdc727f2d7f68734526ef078f4632798ad40791Dan Gohman return new SExtInst(V, Ty, "tmp.", InsertPt); 30711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 30811f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 309890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { 310af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 311c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky Value *LHS = expand(S->getOperand(0)); 312af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 313c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky for (unsigned i = 1; i < S->getNumOperands(); ++i) { 314c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky Value *RHS = expand(S->getOperand(i)); 315af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman RHS = InsertNoopCastOfTo(RHS, Ty); 316c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky Value *ICmp = new ICmpInst(ICmpInst::ICMP_SGT, LHS, RHS, "tmp", InsertPt); 317051a950000e21935165db56695e35bade668193bGabor Greif LHS = SelectInst::Create(ICmp, LHS, RHS, "smax", InsertPt); 318c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky } 319c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky return LHS; 320c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky} 321c54c561c9f7270c055dd7ba75a3a003b771a42d9Nick Lewycky 322890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { 323af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman const Type *Ty = SE.getEffectiveSCEVType(S->getType()); 3243e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky Value *LHS = expand(S->getOperand(0)); 325af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman LHS = InsertNoopCastOfTo(LHS, Ty); 3263e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky for (unsigned i = 1; i < S->getNumOperands(); ++i) { 3273e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky Value *RHS = expand(S->getOperand(i)); 328af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman RHS = InsertNoopCastOfTo(RHS, Ty); 3293e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky Value *ICmp = new ICmpInst(ICmpInst::ICMP_UGT, LHS, RHS, "tmp", InsertPt); 330051a950000e21935165db56695e35bade668193bGabor Greif LHS = SelectInst::Create(ICmp, LHS, RHS, "umax", InsertPt); 3313e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky } 3323e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky return LHS; 3333e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky} 3343e6307698084e7adfc10b739442ae29742beefd0Nick Lewycky 3352d1be87ee40a4a0241d94448173879d9df2bc5b3Dan GohmanValue *SCEVExpander::expandCodeFor(SCEVHandle SH, const Type *Ty, 3366cdc727f2d7f68734526ef078f4632798ad40791Dan Gohman BasicBlock::iterator IP) { 33711f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman // Expand the code for this SCEV. 338af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman assert(SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(SH->getType()) && 3392d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman "non-trivial casts should be done with the SCEVs directly!"); 3406cdc727f2d7f68734526ef078f4632798ad40791Dan Gohman InsertPt = IP; 3412d1be87ee40a4a0241d94448173879d9df2bc5b3Dan Gohman Value *V = expand(SH); 342af79fb5f47b0088c6a8973a7fdbaea96973a429dDan Gohman return InsertNoopCastOfTo(V, Ty); 34311f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman} 34411f6d3b478c4fa09d126833c57fbac1d795ead31Dan Gohman 345890f92b744fb074465bc2b7006ee753a181f62a4Dan GohmanValue *SCEVExpander::expand(const SCEV *S) { 34696fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov // Check to see if we already expanded this. 34796fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov std::map<SCEVHandle, Value*>::iterator I = InsertedExpressions.find(S); 34896fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov if (I != InsertedExpressions.end()) 34996fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return I->second; 35096fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov 35196fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov Value *V = visit(S); 35296fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov InsertedExpressions[S] = V; 35396fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov return V; 35496fea337d27357e9b62abbf3d2d5ce29f1c8e870Anton Korobeynikov} 355