Reassociate.cpp revision 9506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15
14fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner//===- Reassociate.cpp - Reassociate binary expressions -------------------===// 2fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 3b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// The LLVM Compiler Infrastructure 4b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 7fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 8b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell//===----------------------------------------------------------------------===// 94fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// 104fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// This pass reassociates commutative expressions in an order that is designed 119046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner// to promote better constant propagation, GCSE, LICM, PRE, etc. 124fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// 134fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// For example: 4 + (x + 5) -> x + (4 + 5) 144fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// 154fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// In the implementation of this algorithm, constants are assigned rank = 0, 164fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// function arguments are rank = 1, and other values are assigned ranks 174fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// corresponding to the reverse post order traversal of current function 184fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// (starting at 2), which effectively gives values in deep loops higher rank 194fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// than values not in loops. 204fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner// 214fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner//===----------------------------------------------------------------------===// 224fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 2308b43921e18f314c4fd38049291d323830934c36Chris Lattner#define DEBUG_TYPE "reassociate" 244fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner#include "llvm/Transforms/Scalar.h" 250975ed5f4ef7264b45995241717055f8a116bb27Chris Lattner#include "llvm/Constants.h" 26ae74f555522298bef3be8a173163bf778d59adf9Chris Lattner#include "llvm/DerivedTypes.h" 274fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner#include "llvm/Function.h" 28d8e1eea678833cc2b15e4ea69a5a403ba9c3b013Misha Brukman#include "llvm/Instructions.h" 2903afd02ca2486aebb3b29edd2f77920d4e5020fdDale Johannesen#include "llvm/IntrinsicInst.h" 304fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner#include "llvm/Pass.h" 31c9fd097a01383323f166c14c17d3984620cad766Chris Lattner#include "llvm/Assembly/Writer.h" 324fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner#include "llvm/Support/CFG.h" 33551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/Debug.h" 34d3c7b7359d4992b9ab9f8e12ccd0a9b7d2446566Chris Lattner#include "llvm/Support/ValueHandle.h" 35bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner#include "llvm/Support/raw_ostream.h" 36551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/PostOrderIterator.h" 37551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 38ec531233a16605756a84d175178e1ee0fac4791cChris Lattner#include "llvm/ADT/DenseMap.h" 39c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner#include <algorithm> 40d7456026629fc1760a45e6e955e9834246493147Chris Lattnerusing namespace llvm; 41d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 420e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumLinear , "Number of insts linearized"); 430e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumChanged, "Number of insts reassociated"); 440e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumAnnihil, "Number of expr tree annihilated"); 450e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumFactor , "Number of multiplies factored"); 46a92f696b74a99325026ebbdbffd2a44317e0c10bChris Lattner 470e5f499638c8d277b9dc4a4385712177c53b5681Chris Lattnernamespace { 483e8b6631e67e01e4960a7ba4668a50c596607473Chris Lattner struct ValueEntry { 49c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner unsigned Rank; 50c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner Value *Op; 51c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner ValueEntry(unsigned R, Value *O) : Rank(R), Op(O) {} 52c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner }; 53c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner inline bool operator<(const ValueEntry &LHS, const ValueEntry &RHS) { 54c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner return LHS.Rank > RHS.Rank; // Sort so that highest rank goes to start. 55c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner } 56e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner} 57c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 5850cacb2a520b93530e79220a307c907163b9e370Devang Patel#ifndef NDEBUG 59e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner/// PrintOps - Print out the expression identified in the Ops list. 60e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner/// 619f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattnerstatic void PrintOps(Instruction *I, const SmallVectorImpl<ValueEntry> &Ops) { 62e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner Module *M = I->getParent()->getParent()->getParent(); 6379c5d3f9717756dc3ff56cfcaa3ae1a5930c457aChris Lattner errs() << Instruction::getOpcodeName(I->getOpcode()) << " " 641befe643b2a030f5e2433ce0034a27fb65b5f26bChris Lattner << *Ops[0].Op->getType() << '\t'; 657de3b5db26bb3c8dcca5348fb7c0be4f9bd1bcb7Chris Lattner for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 661befe643b2a030f5e2433ce0034a27fb65b5f26bChris Lattner errs() << "[ "; 671befe643b2a030f5e2433ce0034a27fb65b5f26bChris Lattner WriteAsOperand(errs(), Ops[i].Op, false, M); 681befe643b2a030f5e2433ce0034a27fb65b5f26bChris Lattner errs() << ", #" << Ops[i].Rank << "] "; 697de3b5db26bb3c8dcca5348fb7c0be4f9bd1bcb7Chris Lattner } 70e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner} 7159500c8f9a76b3386329b6f837255c16f4e8b61bDevang Patel#endif 72e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 73844731a7f1909f55935e3514c9e713a62d67662eDan Gohmannamespace { 743e8b6631e67e01e4960a7ba4668a50c596607473Chris Lattner class Reassociate : public FunctionPass { 75f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner DenseMap<BasicBlock*, unsigned> RankMap; 76f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner DenseMap<AssertingVH<>, unsigned> ValueRankMap; 77c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner bool MadeChange; 784fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner public: 79ecd94c804a563f2a86572dcf1d2e81f397e19daaNick Lewycky static char ID; // Pass identification, replacement for typeid 80ae73dc1448d25b02cabc7c64c86c64371453dda8Dan Gohman Reassociate() : FunctionPass(&ID) {} 81794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 827e70829632f82de15db187845666aaca6e04b792Chris Lattner bool runOnFunction(Function &F); 834fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 844fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 85cb2610ea037a17115ef3a01a6bdaab4e3cfdca27Chris Lattner AU.setPreservesCFG(); 864fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner } 874fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner private: 887e70829632f82de15db187845666aaca6e04b792Chris Lattner void BuildRankMap(Function &F); 894fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner unsigned getRank(Value *V); 9069e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner Value *ReassociateExpression(BinaryOperator *I); 919f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner void RewriteExprTree(BinaryOperator *I, SmallVectorImpl<ValueEntry> &Ops, 92e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner unsigned Idx = 0); 939f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner Value *OptimizeExpression(BinaryOperator *I, 949f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner SmallVectorImpl<ValueEntry> &Ops); 959f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner Value *OptimizeAdd(Instruction *I, SmallVectorImpl<ValueEntry> &Ops); 969f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner void LinearizeExprTree(BinaryOperator *I, SmallVectorImpl<ValueEntry> &Ops); 97c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner void LinearizeExpr(BinaryOperator *I); 98e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner Value *RemoveFactorFromExpression(Value *V, Value *Factor); 99c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner void ReassociateBB(BasicBlock *BB); 100e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 101e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner void RemoveDeadBinaryOp(Value *V); 1024fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner }; 1034fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner} 1044fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 105844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanchar Reassociate::ID = 0; 106844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanstatic RegisterPass<Reassociate> X("reassociate", "Reassociate expressions"); 107844731a7f1909f55935e3514c9e713a62d67662eDan Gohman 108d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke// Public interface to the Reassociate pass 109d7456026629fc1760a45e6e955e9834246493147Chris LattnerFunctionPass *llvm::createReassociatePass() { return new Reassociate(); } 1104fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 111e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattnervoid Reassociate::RemoveDeadBinaryOp(Value *V) { 112e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer Instruction *Op = dyn_cast<Instruction>(V); 11369e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner if (!Op || !isa<BinaryOperator>(Op) || !Op->use_empty()) 114e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer return; 115e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 116e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer Value *LHS = Op->getOperand(0), *RHS = Op->getOperand(1); 11769e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner 11869e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner ValueRankMap.erase(Op); 11969e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner Op->eraseFromParent(); 120e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner RemoveDeadBinaryOp(LHS); 121e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner RemoveDeadBinaryOp(RHS); 122e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner} 123e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 1249c723199384b16899831937e2800d52f4f953569Chris Lattner 1259c723199384b16899831937e2800d52f4f953569Chris Lattnerstatic bool isUnmovableInstruction(Instruction *I) { 1269c723199384b16899831937e2800d52f4f953569Chris Lattner if (I->getOpcode() == Instruction::PHI || 1279c723199384b16899831937e2800d52f4f953569Chris Lattner I->getOpcode() == Instruction::Alloca || 1289c723199384b16899831937e2800d52f4f953569Chris Lattner I->getOpcode() == Instruction::Load || 1299c723199384b16899831937e2800d52f4f953569Chris Lattner I->getOpcode() == Instruction::Invoke || 13003afd02ca2486aebb3b29edd2f77920d4e5020fdDale Johannesen (I->getOpcode() == Instruction::Call && 13103afd02ca2486aebb3b29edd2f77920d4e5020fdDale Johannesen !isa<DbgInfoIntrinsic>(I)) || 1321628cec4d7fce310d9cde0bcc73997e5a71692c4Reid Spencer I->getOpcode() == Instruction::UDiv || 1331628cec4d7fce310d9cde0bcc73997e5a71692c4Reid Spencer I->getOpcode() == Instruction::SDiv || 1341628cec4d7fce310d9cde0bcc73997e5a71692c4Reid Spencer I->getOpcode() == Instruction::FDiv || 1350a783f783ca05c961234385f5b269d4cf03dbbdbReid Spencer I->getOpcode() == Instruction::URem || 1360a783f783ca05c961234385f5b269d4cf03dbbdbReid Spencer I->getOpcode() == Instruction::SRem || 1370a783f783ca05c961234385f5b269d4cf03dbbdbReid Spencer I->getOpcode() == Instruction::FRem) 1389c723199384b16899831937e2800d52f4f953569Chris Lattner return true; 1399c723199384b16899831937e2800d52f4f953569Chris Lattner return false; 1409c723199384b16899831937e2800d52f4f953569Chris Lattner} 1419c723199384b16899831937e2800d52f4f953569Chris Lattner 1427e70829632f82de15db187845666aaca6e04b792Chris Lattnervoid Reassociate::BuildRankMap(Function &F) { 1436007cb6c4d923e2dee4a1133fb6d1bb00a37062dChris Lattner unsigned i = 2; 144fb5be090f59997deb7a2e89c92bac19528ba6755Chris Lattner 145fb5be090f59997deb7a2e89c92bac19528ba6755Chris Lattner // Assign distinct ranks to function arguments 146e4d5c441e04bdc00ccf1804744af670655123b07Chris Lattner for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) 147d3c7b7359d4992b9ab9f8e12ccd0a9b7d2446566Chris Lattner ValueRankMap[&*I] = ++i; 148fb5be090f59997deb7a2e89c92bac19528ba6755Chris Lattner 1497e70829632f82de15db187845666aaca6e04b792Chris Lattner ReversePostOrderTraversal<Function*> RPOT(&F); 1504fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner for (ReversePostOrderTraversal<Function*>::rpo_iterator I = RPOT.begin(), 1519c723199384b16899831937e2800d52f4f953569Chris Lattner E = RPOT.end(); I != E; ++I) { 1529c723199384b16899831937e2800d52f4f953569Chris Lattner BasicBlock *BB = *I; 1539c723199384b16899831937e2800d52f4f953569Chris Lattner unsigned BBRank = RankMap[BB] = ++i << 16; 1549c723199384b16899831937e2800d52f4f953569Chris Lattner 1559c723199384b16899831937e2800d52f4f953569Chris Lattner // Walk the basic block, adding precomputed ranks for any instructions that 1569c723199384b16899831937e2800d52f4f953569Chris Lattner // we cannot move. This ensures that the ranks for these instructions are 1579c723199384b16899831937e2800d52f4f953569Chris Lattner // all different in the block. 1589c723199384b16899831937e2800d52f4f953569Chris Lattner for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) 1599c723199384b16899831937e2800d52f4f953569Chris Lattner if (isUnmovableInstruction(I)) 160d3c7b7359d4992b9ab9f8e12ccd0a9b7d2446566Chris Lattner ValueRankMap[&*I] = ++BBRank; 1619c723199384b16899831937e2800d52f4f953569Chris Lattner } 1624fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner} 1634fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 1644fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattnerunsigned Reassociate::getRank(Value *V) { 16508b43921e18f314c4fd38049291d323830934c36Chris Lattner Instruction *I = dyn_cast<Instruction>(V); 166f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner if (I == 0) { 167f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner if (isa<Argument>(V)) return ValueRankMap[V]; // Function argument. 168f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner return 0; // Otherwise it's a global or constant, rank 0. 169f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner } 1704fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 171f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner if (unsigned Rank = ValueRankMap[I]) 172f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner return Rank; // Rank already known? 17300b16889ab461b7ecef1c91ade101186b7f1fce2Jeff Cohen 17408b43921e18f314c4fd38049291d323830934c36Chris Lattner // If this is an expression, return the 1+MAX(rank(LHS), rank(RHS)) so that 17508b43921e18f314c4fd38049291d323830934c36Chris Lattner // we can reassociate expressions for code motion! Since we do not recurse 17608b43921e18f314c4fd38049291d323830934c36Chris Lattner // for PHI nodes, we cannot have infinite recursion here, because there 17708b43921e18f314c4fd38049291d323830934c36Chris Lattner // cannot be loops in the value graph that do not go through PHI nodes. 17808b43921e18f314c4fd38049291d323830934c36Chris Lattner unsigned Rank = 0, MaxRank = RankMap[I->getParent()]; 17908b43921e18f314c4fd38049291d323830934c36Chris Lattner for (unsigned i = 0, e = I->getNumOperands(); 18008b43921e18f314c4fd38049291d323830934c36Chris Lattner i != e && Rank != MaxRank; ++i) 18108b43921e18f314c4fd38049291d323830934c36Chris Lattner Rank = std::max(Rank, getRank(I->getOperand(i))); 18200b16889ab461b7ecef1c91ade101186b7f1fce2Jeff Cohen 183cc8a2b98f28c10d93f45489b8c6f0c8b8205bb3bChris Lattner // If this is a not or neg instruction, do not count it for rank. This 184cc8a2b98f28c10d93f45489b8c6f0c8b8205bb3bChris Lattner // assures us that X and ~X will have the same rank. 18542a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner if (!I->getType()->isInteger() || 186fa82b6eba4e1584d7dba291c28fe908272e1e002Owen Anderson (!BinaryOperator::isNot(I) && !BinaryOperator::isNeg(I))) 187cc8a2b98f28c10d93f45489b8c6f0c8b8205bb3bChris Lattner ++Rank; 188cc8a2b98f28c10d93f45489b8c6f0c8b8205bb3bChris Lattner 189bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner //DEBUG(errs() << "Calculated Rank[" << V->getName() << "] = " 190bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner // << Rank << "\n"); 19100b16889ab461b7ecef1c91ade101186b7f1fce2Jeff Cohen 192f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner return ValueRankMap[I] = Rank; 1934fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner} 1944fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 195c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner/// isReassociableOp - Return true if V is an instruction of the specified 196c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner/// opcode and if it only has one use. 197c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattnerstatic BinaryOperator *isReassociableOp(Value *V, unsigned Opcode) { 198e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner if ((V->hasOneUse() || V->use_empty()) && isa<Instruction>(V) && 199c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner cast<Instruction>(V)->getOpcode() == Opcode) 200c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner return cast<BinaryOperator>(V); 201c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner return 0; 202c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner} 2034fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 204f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner/// LowerNegateToMultiply - Replace 0-X with X*-1. 205f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner/// 206f4978e2094a08760d4fa8a07052091cb7276eec7Dale Johannesenstatic Instruction *LowerNegateToMultiply(Instruction *Neg, 207f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner DenseMap<AssertingVH<>, unsigned> &ValueRankMap) { 208a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant *Cst = Constant::getAllOnesValue(Neg->getType()); 209f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner 2107cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif Instruction *Res = BinaryOperator::CreateMul(Neg->getOperand(1), Cst, "",Neg); 211f4978e2094a08760d4fa8a07052091cb7276eec7Dale Johannesen ValueRankMap.erase(Neg); 2126934a04a8c15e9971cd1ea4d5c8df2d7afdd5be5Chris Lattner Res->takeName(Neg); 213f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner Neg->replaceAllUsesWith(Res); 214f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner Neg->eraseFromParent(); 215f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner return Res; 216f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner} 217f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner 218c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner// Given an expression of the form '(A+B)+(D+C)', turn it into '(((A+B)+C)+D)'. 219c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner// Note that if D is also part of the expression tree that we recurse to 220c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner// linearize it as well. Besides that case, this does not recurse into A,B, or 221c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner// C. 222c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattnervoid Reassociate::LinearizeExpr(BinaryOperator *I) { 223c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner BinaryOperator *LHS = cast<BinaryOperator>(I->getOperand(0)); 224c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner BinaryOperator *RHS = cast<BinaryOperator>(I->getOperand(1)); 22500b16889ab461b7ecef1c91ade101186b7f1fce2Jeff Cohen assert(isReassociableOp(LHS, I->getOpcode()) && 226c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner isReassociableOp(RHS, I->getOpcode()) && 227c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner "Not an expression that needs linearization?"); 228c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 229bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner DEBUG(errs() << "Linear" << *LHS << '\n' << *RHS << '\n' << *I << '\n'); 230c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 231c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // Move the RHS instruction to live immediately before I, avoiding breaking 232c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // dominator properties. 2334bc5f8071a28b6fc4f4c2207dd03a5f747d0d84bChris Lattner RHS->moveBefore(I); 234c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 235c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // Move operands around to do the linearization. 236c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner I->setOperand(1, RHS->getOperand(0)); 237c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner RHS->setOperand(0, LHS); 238c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner I->setOperand(0, RHS); 23900b16889ab461b7ecef1c91ade101186b7f1fce2Jeff Cohen 240c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner ++NumLinear; 241c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner MadeChange = true; 242bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner DEBUG(errs() << "Linearized: " << *I << '\n'); 243fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 244c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // If D is part of this expression tree, tail recurse. 245c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner if (isReassociableOp(I->getOperand(1), I->getOpcode())) 246c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner LinearizeExpr(I); 247c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner} 2484fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 249e4b730441dab4aff9a69aeddbdea98990e7703c4Chris Lattner 250c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner/// LinearizeExprTree - Given an associative binary expression tree, traverse 251c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner/// all of the uses putting it into canonical form. This forces a left-linear 252c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner/// form of the the expression (((a+b)+c)+d), and collects information about the 253c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner/// rank of the non-tree operands. 254c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner/// 255e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner/// NOTE: These intentionally destroys the expression tree operands (turning 256e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner/// them into undef values) to reduce #uses of the values. This means that the 257e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner/// caller MUST use something like RewriteExprTree to put the values back in. 258e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner/// 259c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattnervoid Reassociate::LinearizeExprTree(BinaryOperator *I, 2609f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner SmallVectorImpl<ValueEntry> &Ops) { 261c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner Value *LHS = I->getOperand(0), *RHS = I->getOperand(1); 262c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner unsigned Opcode = I->getOpcode(); 263c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 264c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // First step, linearize the expression if it is in ((A+B)+(C+D)) form. 265c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner BinaryOperator *LHSBO = isReassociableOp(LHS, Opcode); 266c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner BinaryOperator *RHSBO = isReassociableOp(RHS, Opcode); 267c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 268f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner // If this is a multiply expression tree and it contains internal negations, 269f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner // transform them into multiplies by -1 so they can be reassociated. 270f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner if (I->getOpcode() == Instruction::Mul) { 271fa82b6eba4e1584d7dba291c28fe908272e1e002Owen Anderson if (!LHSBO && LHS->hasOneUse() && BinaryOperator::isNeg(LHS)) { 272e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewycky LHS = LowerNegateToMultiply(cast<Instruction>(LHS), ValueRankMap); 273f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner LHSBO = isReassociableOp(LHS, Opcode); 274f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner } 275fa82b6eba4e1584d7dba291c28fe908272e1e002Owen Anderson if (!RHSBO && RHS->hasOneUse() && BinaryOperator::isNeg(RHS)) { 276e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewycky RHS = LowerNegateToMultiply(cast<Instruction>(RHS), ValueRankMap); 277f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner RHSBO = isReassociableOp(RHS, Opcode); 278f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner } 279f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner } 280f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner 281c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner if (!LHSBO) { 282c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner if (!RHSBO) { 283c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // Neither the LHS or RHS as part of the tree, thus this is a leaf. As 284c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // such, just remember these operands and their rank. 285c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner Ops.push_back(ValueEntry(getRank(LHS), LHS)); 286c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner Ops.push_back(ValueEntry(getRank(RHS), RHS)); 287e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner 288e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner // Clear the leaves out. 2899e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson I->setOperand(0, UndefValue::get(I->getType())); 2909e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson I->setOperand(1, UndefValue::get(I->getType())); 291c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner return; 292c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner } 293f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner 294f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner // Turn X+(Y+Z) -> (Y+Z)+X 295f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner std::swap(LHSBO, RHSBO); 296f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner std::swap(LHS, RHS); 297f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner bool Success = !I->swapOperands(); 298f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner assert(Success && "swapOperands failed"); 299f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner Success = false; 300f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner MadeChange = true; 301c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner } else if (RHSBO) { 302c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // Turn (A+B)+(C+D) -> (((A+B)+C)+D). This guarantees the the RHS is not 303c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // part of the expression tree. 304c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner LinearizeExpr(I); 305c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner LHS = LHSBO = cast<BinaryOperator>(I->getOperand(0)); 306c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner RHS = I->getOperand(1); 307c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner RHSBO = 0; 3084fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner } 309fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 310c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // Okay, now we know that the LHS is a nested expression and that the RHS is 311c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // not. Perform reassociation. 312c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner assert(!isReassociableOp(RHS, Opcode) && "LinearizeExpr failed!"); 3134fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 314c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // Move LHS right before I to make sure that the tree expression dominates all 315c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // values. 3164bc5f8071a28b6fc4f4c2207dd03a5f747d0d84bChris Lattner LHSBO->moveBefore(I); 317c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 318c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // Linearize the expression tree on the LHS. 319c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner LinearizeExprTree(LHSBO, Ops); 320c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 321c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // Remember the RHS operand and its rank. 322c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner Ops.push_back(ValueEntry(getRank(RHS), RHS)); 323e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner 324e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner // Clear the RHS leaf out. 3259e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson I->setOperand(1, UndefValue::get(I->getType())); 326c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner} 327c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 328c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner// RewriteExprTree - Now that the operands for this expression tree are 329c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner// linearized and optimized, emit them in-order. This function is written to be 330c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner// tail recursive. 331e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattnervoid Reassociate::RewriteExprTree(BinaryOperator *I, 3329f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner SmallVectorImpl<ValueEntry> &Ops, 333e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner unsigned i) { 334c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner if (i+2 == Ops.size()) { 335c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner if (I->getOperand(0) != Ops[i].Op || 336c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner I->getOperand(1) != Ops[i+1].Op) { 337e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner Value *OldLHS = I->getOperand(0); 338bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner DEBUG(errs() << "RA: " << *I << '\n'); 339c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner I->setOperand(0, Ops[i].Op); 340c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner I->setOperand(1, Ops[i+1].Op); 341bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner DEBUG(errs() << "TO: " << *I << '\n'); 342c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner MadeChange = true; 343c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner ++NumChanged; 344e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 345e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner // If we reassociated a tree to fewer operands (e.g. (1+a+2) -> (a+3) 346e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner // delete the extra, now dead, nodes. 347e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner RemoveDeadBinaryOp(OldLHS); 348c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner } 349c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner return; 350c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner } 351c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner assert(i+2 < Ops.size() && "Ops index out of range!"); 352c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 353c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner if (I->getOperand(1) != Ops[i].Op) { 354bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner DEBUG(errs() << "RA: " << *I << '\n'); 355c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner I->setOperand(1, Ops[i].Op); 356bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner DEBUG(errs() << "TO: " << *I << '\n'); 357c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner MadeChange = true; 358c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner ++NumChanged; 359c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner } 360e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 361e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner BinaryOperator *LHS = cast<BinaryOperator>(I->getOperand(0)); 362e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner assert(LHS->getOpcode() == I->getOpcode() && 363e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner "Improper expression tree!"); 364e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 365e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner // Compactify the tree instructions together with each other to guarantee 366e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner // that the expression tree is dominated by all of Ops. 367e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner LHS->moveBefore(I); 368e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner RewriteExprTree(LHS, Ops, i+1); 3694fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner} 3704fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 3714fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 372c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 373a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner// NegateValue - Insert instructions before the instruction pointed to by BI, 374a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner// that computes the negative version of the value specified. The negative 375a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner// version of the value is returned, and BI is left pointing at the instruction 376a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner// that should be processed next by the reassociation pass. 377a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner// 378e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewyckystatic Value *NegateValue(Value *V, Instruction *BI) { 37935239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner if (Constant *C = dyn_cast<Constant>(V)) 38035239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner return ConstantExpr::getNeg(C); 38135239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner 382a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // We are trying to expose opportunity for reassociation. One of the things 383a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // that we want to do to achieve this is to push a negation as deep into an 384a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // expression chain as possible, to expose the add instructions. In practice, 385a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // this means that we turn this: 386a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // X = -(A+12+C+D) into X = -A + -12 + -C + -D = -12 + -A + -C + -D 387a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // so that later, a: Y = 12+X could get reassociated with the -12 to eliminate 388a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // the constants. We assume that instcombine will clean up the mess later if 3899046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner // we introduce tons of unnecessary negation instructions. 390a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // 391a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner if (Instruction *I = dyn_cast<Instruction>(V)) 392fd05924946ebfcfb3409b21996cfd0836e4ddb31Chris Lattner if (I->getOpcode() == Instruction::Add && I->hasOneUse()) { 3932cd85da3ed8e703729fb5adfe8cc2f9b1dd2f6a8Chris Lattner // Push the negates through the add. 394e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewycky I->setOperand(0, NegateValue(I->getOperand(0), BI)); 395e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewycky I->setOperand(1, NegateValue(I->getOperand(1), BI)); 3962cd85da3ed8e703729fb5adfe8cc2f9b1dd2f6a8Chris Lattner 3972cd85da3ed8e703729fb5adfe8cc2f9b1dd2f6a8Chris Lattner // We must move the add instruction here, because the neg instructions do 3982cd85da3ed8e703729fb5adfe8cc2f9b1dd2f6a8Chris Lattner // not dominate the old add instruction in general. By moving it, we are 3992cd85da3ed8e703729fb5adfe8cc2f9b1dd2f6a8Chris Lattner // assured that the neg instructions we just inserted dominate the 4002cd85da3ed8e703729fb5adfe8cc2f9b1dd2f6a8Chris Lattner // instruction we are about to insert after them. 401a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // 4022cd85da3ed8e703729fb5adfe8cc2f9b1dd2f6a8Chris Lattner I->moveBefore(BI); 4032cd85da3ed8e703729fb5adfe8cc2f9b1dd2f6a8Chris Lattner I->setName(I->getName()+".neg"); 4042cd85da3ed8e703729fb5adfe8cc2f9b1dd2f6a8Chris Lattner return I; 405a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner } 40635239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner 40735239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner // Okay, we need to materialize a negated version of V with an instruction. 40835239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner // Scan the use lists of V to see if we have one already. 40935239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E;++UI){ 41035239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner if (!BinaryOperator::isNeg(*UI)) continue; 41135239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner 41235239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner // We found one! Now we have to make sure that the definition dominates 41335239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner // this use. We do this by moving it to the entry block (if it is a 41435239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner // non-instruction value) or right after the definition. These negates will 41535239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner // be zapped by reassociate later, so we don't need much finesse here. 41635239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner BinaryOperator *TheNeg = cast<BinaryOperator>(*UI); 41735239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner 41835239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner BasicBlock::iterator InsertPt; 41935239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner if (Instruction *InstInput = dyn_cast<Instruction>(V)) { 42035239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(InstInput)) { 42135239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner InsertPt = II->getNormalDest()->begin(); 42235239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner } else { 42335239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner InsertPt = InstInput; 42435239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner ++InsertPt; 42535239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner } 42635239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner while (isa<PHINode>(InsertPt)) ++InsertPt; 42735239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner } else { 42835239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner InsertPt = TheNeg->getParent()->getParent()->getEntryBlock().begin(); 42935239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner } 43035239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner TheNeg->moveBefore(InsertPt); 43135239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner return TheNeg; 43235239934517c6fcd52e3e965f40e03f74aa4d11dChris Lattner } 433a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner 434a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // Insert a 'neg' instruction that subtracts the value from zero to get the 435a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner // negation. 4364ae5126d041768ab9665cf2f11c024becd76c41fDan Gohman return BinaryOperator::CreateNeg(V, V->getName() + ".neg", BI); 437a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner} 438a36e6c8cd58c2876decd2d0402064ac349bbec71Chris Lattner 4399bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner/// ShouldBreakUpSubtract - Return true if we should break up this subtract of 4409bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner/// X-Y into (X + -Y). 441e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewyckystatic bool ShouldBreakUpSubtract(Instruction *Sub) { 4429bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner // If this is a negation, we can't split it up! 443fa82b6eba4e1584d7dba291c28fe908272e1e002Owen Anderson if (BinaryOperator::isNeg(Sub)) 4449bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner return false; 4459bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner 4469bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner // Don't bother to break this up unless either the LHS is an associable add or 4470b0803ae1508ff514dd7b471a2a3bcd1e83cb0efChris Lattner // subtract or if this is only used by one. 4480b0803ae1508ff514dd7b471a2a3bcd1e83cb0efChris Lattner if (isReassociableOp(Sub->getOperand(0), Instruction::Add) || 4490b0803ae1508ff514dd7b471a2a3bcd1e83cb0efChris Lattner isReassociableOp(Sub->getOperand(0), Instruction::Sub)) 4509bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner return true; 4510b0803ae1508ff514dd7b471a2a3bcd1e83cb0efChris Lattner if (isReassociableOp(Sub->getOperand(1), Instruction::Add) || 4525329bb22e9b6374d62919981c1ef8775b42945ebChris Lattner isReassociableOp(Sub->getOperand(1), Instruction::Sub)) 4539bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner return true; 4540b0803ae1508ff514dd7b471a2a3bcd1e83cb0efChris Lattner if (Sub->hasOneUse() && 4550b0803ae1508ff514dd7b471a2a3bcd1e83cb0efChris Lattner (isReassociableOp(Sub->use_back(), Instruction::Add) || 4560b0803ae1508ff514dd7b471a2a3bcd1e83cb0efChris Lattner isReassociableOp(Sub->use_back(), Instruction::Sub))) 4579bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner return true; 4589bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner 4599bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner return false; 4609bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner} 4619bc5ed78c860694ccb4ea63c96c2c9212a8b245bChris Lattner 46208b43921e18f314c4fd38049291d323830934c36Chris Lattner/// BreakUpSubtract - If we have (X-Y), and if either X is an add, or if this is 46308b43921e18f314c4fd38049291d323830934c36Chris Lattner/// only used by an add, transform this into (X+(0-Y)) to promote better 46408b43921e18f314c4fd38049291d323830934c36Chris Lattner/// reassociation. 465e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewyckystatic Instruction *BreakUpSubtract(Instruction *Sub, 466f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner DenseMap<AssertingVH<>, unsigned> &ValueRankMap) { 4679046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner // Convert a subtract into an add and a neg instruction. This allows sub 4689046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner // instructions to be commuted with other add instructions. 46908b43921e18f314c4fd38049291d323830934c36Chris Lattner // 4709046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner // Calculate the negative value of Operand 1 of the sub instruction, 4719046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner // and set it as the RHS of the add instruction we just made. 47208b43921e18f314c4fd38049291d323830934c36Chris Lattner // 473e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewycky Value *NegVal = NegateValue(Sub->getOperand(1), Sub); 47408b43921e18f314c4fd38049291d323830934c36Chris Lattner Instruction *New = 4757cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif BinaryOperator::CreateAdd(Sub->getOperand(0), NegVal, "", Sub); 4766934a04a8c15e9971cd1ea4d5c8df2d7afdd5be5Chris Lattner New->takeName(Sub); 47708b43921e18f314c4fd38049291d323830934c36Chris Lattner 47808b43921e18f314c4fd38049291d323830934c36Chris Lattner // Everyone now refers to the add instruction. 479f4978e2094a08760d4fa8a07052091cb7276eec7Dale Johannesen ValueRankMap.erase(Sub); 48008b43921e18f314c4fd38049291d323830934c36Chris Lattner Sub->replaceAllUsesWith(New); 48108b43921e18f314c4fd38049291d323830934c36Chris Lattner Sub->eraseFromParent(); 48200b16889ab461b7ecef1c91ade101186b7f1fce2Jeff Cohen 483bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner DEBUG(errs() << "Negated: " << *New << '\n'); 48408b43921e18f314c4fd38049291d323830934c36Chris Lattner return New; 48508b43921e18f314c4fd38049291d323830934c36Chris Lattner} 48608b43921e18f314c4fd38049291d323830934c36Chris Lattner 4870975ed5f4ef7264b45995241717055f8a116bb27Chris Lattner/// ConvertShiftToMul - If this is a shift of a reassociable multiply or is used 4880975ed5f4ef7264b45995241717055f8a116bb27Chris Lattner/// by one, change this into a multiply by a constant to assist with further 4890975ed5f4ef7264b45995241717055f8a116bb27Chris Lattner/// reassociation. 490f4978e2094a08760d4fa8a07052091cb7276eec7Dale Johannesenstatic Instruction *ConvertShiftToMul(Instruction *Shl, 491f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner DenseMap<AssertingVH<>, unsigned> &ValueRankMap) { 49222a66c41f3ab42c15437033851395b0b8288681bChris Lattner // If an operand of this shift is a reassociable multiply, or if the shift 49322a66c41f3ab42c15437033851395b0b8288681bChris Lattner // is used by a reassociable multiply or add, turn into a multiply. 49422a66c41f3ab42c15437033851395b0b8288681bChris Lattner if (isReassociableOp(Shl->getOperand(0), Instruction::Mul) || 49522a66c41f3ab42c15437033851395b0b8288681bChris Lattner (Shl->hasOneUse() && 49622a66c41f3ab42c15437033851395b0b8288681bChris Lattner (isReassociableOp(Shl->use_back(), Instruction::Mul) || 49722a66c41f3ab42c15437033851395b0b8288681bChris Lattner isReassociableOp(Shl->use_back(), Instruction::Add)))) { 498eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Constant *MulCst = ConstantInt::get(Shl->getType(), 1); 499f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner MulCst = ConstantExpr::getShl(MulCst, cast<Constant>(Shl->getOperand(1))); 50022a66c41f3ab42c15437033851395b0b8288681bChris Lattner 501f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner Instruction *Mul = 502f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner BinaryOperator::CreateMul(Shl->getOperand(0), MulCst, "", Shl); 503f4978e2094a08760d4fa8a07052091cb7276eec7Dale Johannesen ValueRankMap.erase(Shl); 5046934a04a8c15e9971cd1ea4d5c8df2d7afdd5be5Chris Lattner Mul->takeName(Shl); 50522a66c41f3ab42c15437033851395b0b8288681bChris Lattner Shl->replaceAllUsesWith(Mul); 50622a66c41f3ab42c15437033851395b0b8288681bChris Lattner Shl->eraseFromParent(); 50722a66c41f3ab42c15437033851395b0b8288681bChris Lattner return Mul; 50822a66c41f3ab42c15437033851395b0b8288681bChris Lattner } 50922a66c41f3ab42c15437033851395b0b8288681bChris Lattner return 0; 5100975ed5f4ef7264b45995241717055f8a116bb27Chris Lattner} 5110975ed5f4ef7264b45995241717055f8a116bb27Chris Lattner 512109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner// Scan backwards and forwards among values with the same rank as element i to 5139506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner// see if X exists. If X does not exist, return i. This is useful when 5149506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner// scanning for 'x' when we see '-x' because they both get the same rank. 5159f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattnerstatic unsigned FindInOperandList(SmallVectorImpl<ValueEntry> &Ops, unsigned i, 516109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner Value *X) { 517109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner unsigned XRank = Ops[i].Rank; 518109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner unsigned e = Ops.size(); 519109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner for (unsigned j = i+1; j != e && Ops[j].Rank == XRank; ++j) 520109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner if (Ops[j].Op == X) 521109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner return j; 5229506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner // Scan backwards. 523109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner for (unsigned j = i-1; j != ~0U && Ops[j].Rank == XRank; --j) 524109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner if (Ops[j].Op == X) 525109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner return j; 526109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner return i; 527109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner} 528109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner 529e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner/// EmitAddTreeOfValues - Emit a tree of add instructions, summing Ops together 530e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner/// and returning the result. Insert the tree before I. 5318d93b259f6d6ece634df86d5df453efc0c918546Chris Lattnerstatic Value *EmitAddTreeOfValues(Instruction *I, SmallVectorImpl<Value*> &Ops){ 532e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner if (Ops.size() == 1) return Ops.back(); 533e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 534e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner Value *V1 = Ops.back(); 535e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner Ops.pop_back(); 536e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner Value *V2 = EmitAddTreeOfValues(I, Ops); 5377cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif return BinaryOperator::CreateAdd(V2, V1, "tmp", I); 538e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner} 539e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 540e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner/// RemoveFactorFromExpression - If V is an expression tree that is a 541e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner/// multiplication sequence, and if this sequence contains a multiply by Factor, 542e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner/// remove Factor from the tree and return the new tree. 543e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris LattnerValue *Reassociate::RemoveFactorFromExpression(Value *V, Value *Factor) { 544e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner BinaryOperator *BO = isReassociableOp(V, Instruction::Mul); 545e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner if (!BO) return 0; 546e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 5479f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner SmallVector<ValueEntry, 8> Factors; 548e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner LinearizeExprTree(BO, Factors); 549e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 550e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner bool FoundFactor = false; 5519506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner bool NeedsNegate = false; 5529506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner for (unsigned i = 0, e = Factors.size(); i != e; ++i) { 553e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner if (Factors[i].Op == Factor) { 554e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner FoundFactor = true; 555e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner Factors.erase(Factors.begin()+i); 556e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner break; 557e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner } 5589506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner 5599506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner // If this is a negative version of this factor, remove it. 5609506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner if (ConstantInt *FC1 = dyn_cast<ConstantInt>(Factor)) 5619506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner if (ConstantInt *FC2 = dyn_cast<ConstantInt>(Factors[i].Op)) 5629506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner if (FC1->getValue() == -FC2->getValue()) { 5639506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner FoundFactor = NeedsNegate = true; 5649506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner Factors.erase(Factors.begin()+i); 5659506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner break; 5669506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner } 5679506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner } 5689506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner 569e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner if (!FoundFactor) { 570e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner // Make sure to restore the operands to the expression tree. 571e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner RewriteExprTree(BO, Factors); 572e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner return 0; 573e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner } 574e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 5759506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner BasicBlock::iterator InsertPt = BO; ++InsertPt; 5769506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner 5771e7558b65689999089f53ce40ff07564cf498c68Chris Lattner // If this was just a single multiply, remove the multiply and return the only 5781e7558b65689999089f53ce40ff07564cf498c68Chris Lattner // remaining operand. 5791e7558b65689999089f53ce40ff07564cf498c68Chris Lattner if (Factors.size() == 1) { 5801e7558b65689999089f53ce40ff07564cf498c68Chris Lattner ValueRankMap.erase(BO); 5811e7558b65689999089f53ce40ff07564cf498c68Chris Lattner BO->eraseFromParent(); 5829506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner V = Factors[0].Op; 5839506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner } else { 5849506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner RewriteExprTree(BO, Factors); 5859506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner V = BO; 5861e7558b65689999089f53ce40ff07564cf498c68Chris Lattner } 587e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 5889506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner if (NeedsNegate) 5899506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner V = BinaryOperator::CreateNeg(V, "neg", InsertPt); 5909506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner 5919506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner return V; 592e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner} 593e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 594e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner/// FindSingleUseMultiplyFactors - If V is a single-use multiply, recursively 595e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner/// add its operands as factors, otherwise add V to the list of factors. 596e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattnerstatic void FindSingleUseMultiplyFactors(Value *V, 5978d93b259f6d6ece634df86d5df453efc0c918546Chris Lattner SmallVectorImpl<Value*> &Factors) { 598e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner BinaryOperator *BO; 599e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner if ((!V->hasOneUse() && !V->use_empty()) || 600e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner !(BO = dyn_cast<BinaryOperator>(V)) || 601e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner BO->getOpcode() != Instruction::Mul) { 602e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner Factors.push_back(V); 603e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner return; 604e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner } 605e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner 606e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner // Otherwise, add the LHS and RHS to the list of factors. 607e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner FindSingleUseMultiplyFactors(BO->getOperand(1), Factors); 608e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner FindSingleUseMultiplyFactors(BO->getOperand(0), Factors); 609e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner} 610e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner 611f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner/// OptimizeAndOrXor - Optimize a series of operands to an 'and', 'or', or 'xor' 612f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner/// instruction. This optimizes based on identities. If it can be reduced to 613f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner/// a single Value, it is returned, otherwise the Ops list is mutated as 614f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner/// necessary. 6159f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattnerstatic Value *OptimizeAndOrXor(unsigned Opcode, 6169f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner SmallVectorImpl<ValueEntry> &Ops) { 617f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner // Scan the operand lists looking for X and ~X pairs, along with X,X pairs. 618f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner // If we find any, we can simplify the expression. X&~X == 0, X|~X == -1. 619f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 620f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner // First, check for X and ~X in the operand list. 621f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner assert(i < Ops.size()); 622f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner if (BinaryOperator::isNot(Ops[i].Op)) { // Cannot occur for ^. 623f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner Value *X = BinaryOperator::getNotArgument(Ops[i].Op); 624f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner unsigned FoundX = FindInOperandList(Ops, i, X); 625f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner if (FoundX != i) { 6269fdaefad580194353f34b6d72669591f8f9d811aChris Lattner if (Opcode == Instruction::And) // ...&X&~X = 0 627f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner return Constant::getNullValue(X->getType()); 628f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner 6299fdaefad580194353f34b6d72669591f8f9d811aChris Lattner if (Opcode == Instruction::Or) // ...|X|~X = -1 630f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner return Constant::getAllOnesValue(X->getType()); 631f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner } 632f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner } 633f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner 634f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner // Next, check for duplicate pairs of values, which we assume are next to 635f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner // each other, due to our sorting criteria. 636f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner assert(i < Ops.size()); 637f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner if (i+1 != Ops.size() && Ops[i+1].Op == Ops[i].Op) { 638f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner if (Opcode == Instruction::And || Opcode == Instruction::Or) { 639f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner // Drop duplicate values for And and Or. 640f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner Ops.erase(Ops.begin()+i); 641f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner --i; --e; 642f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner ++NumAnnihil; 643f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner continue; 644f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner } 645f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner 646f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner // Drop pairs of values for Xor. 647f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner assert(Opcode == Instruction::Xor); 648f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner if (e == 2) 649f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner return Constant::getNullValue(Ops[0].Op->getType()); 650f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner 6519046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner // Y ^ X^X -> Y 652f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner Ops.erase(Ops.begin()+i, Ops.begin()+i+2); 653f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner i -= 1; e -= 2; 654f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner ++NumAnnihil; 655f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner } 656f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner } 657f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner return 0; 658f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner} 659e9efecbf470100696355f32ea8b6ab942183ac6cChris Lattner 660f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner/// OptimizeAdd - Optimize a series of operands to an 'add' instruction. This 661f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner/// optimizes based on identities. If it can be reduced to a single Value, it 662f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner/// is returned, otherwise the Ops list is mutated as necessary. 6639f7b7089be854c323f8d9a4627d80e47adf496e6Chris LattnerValue *Reassociate::OptimizeAdd(Instruction *I, 6649f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner SmallVectorImpl<ValueEntry> &Ops) { 665f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner // Scan the operand lists looking for X and -X pairs. If we find any, we 66669e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // can simplify the expression. X+-X == 0. While we're at it, scan for any 66769e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // duplicates. We want to canonicalize Y+Y+Y+Z -> 3*Y+Z. 6689506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner // 6699506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner // TODO: We could handle "X + ~X" -> "-1" if we wanted, since "-X = ~X+1". 6709506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner // 671f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 67269e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner Value *TheOp = Ops[i].Op; 67369e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // Check to see if we've seen this operand before. If so, we factor all 674f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner // instances of the operand together. Due to our sorting criteria, we know 675f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner // that these need to be next to each other in the vector. 676f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner if (i+1 != Ops.size() && Ops[i+1].Op == TheOp) { 677f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner // Rescan the list, remove all instances of this operand from the expr. 67869e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner unsigned NumFound = 0; 679f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner do { 680f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner Ops.erase(Ops.begin()+i); 68169e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner ++NumFound; 682f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner } while (i != Ops.size() && Ops[i].Op == TheOp); 683f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner 684f8a447de162a2896a8a044931fb63de713dbc6b9Chris Lattner DEBUG(errs() << "\nFACTORING [" << NumFound << "]: " << *TheOp << '\n'); 68569e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner ++NumFactor; 68669e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner 68769e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // Insert a new multiply. 68869e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner Value *Mul = ConstantInt::get(cast<IntegerType>(I->getType()), NumFound); 68969e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner Mul = BinaryOperator::CreateMul(TheOp, Mul, "factor", I); 69069e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner 69169e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // Now that we have inserted a multiply, optimize it. This allows us to 69269e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // handle cases that require multiple factoring steps, such as this: 69369e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // (X*2) + (X*2) + (X*2) -> (X*2)*3 -> X*6 69469e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner Mul = ReassociateExpression(cast<BinaryOperator>(Mul)); 69569e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner 69669e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // If every add operand was a duplicate, return the multiply. 69769e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner if (Ops.empty()) 69869e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner return Mul; 69969e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner 70069e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // Otherwise, we had some input that didn't have the dupe, such as 70169e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // "A + A + B" -> "A*2 + B". Add the new multiply to the list of 70269e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // things being added by this operation. 70369e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner Ops.insert(Ops.begin(), ValueEntry(getRank(Mul), Mul)); 704f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner 705f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner --i; 706f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner e = Ops.size(); 707f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner continue; 70869e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner } 70969e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner 710f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner // Check for X and -X in the operand list. 71169e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner if (!BinaryOperator::isNeg(TheOp)) 712f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner continue; 713f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner 71469e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner Value *X = BinaryOperator::getNegArgument(TheOp); 715f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner unsigned FoundX = FindInOperandList(Ops, i, X); 716f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner if (FoundX == i) 717f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner continue; 718f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner 719f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner // Remove X and -X from the operand list. 7209fdaefad580194353f34b6d72669591f8f9d811aChris Lattner if (Ops.size() == 2) 721f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner return Constant::getNullValue(X->getType()); 722f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner 723f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner Ops.erase(Ops.begin()+i); 724f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner if (i < FoundX) 725f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner --FoundX; 726f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner else 727f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner --i; // Need to back up an extra one. 728f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner Ops.erase(Ops.begin()+FoundX); 729f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner ++NumAnnihil; 730f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner --i; // Revisit element. 731f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner e -= 2; // Removed two elements. 732f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner } 73394285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 73494285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // Scan the operand list, checking to see if there are any common factors 73594285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // between operands. Consider something like A*A+A*B*C+D. We would like to 73694285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // reassociate this to A*(A+B*C)+D, which reduces the number of multiplies. 73794285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // To efficiently find this, we count the number of times a factor occurs 73894285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // for any ADD operands that are MULs. 73994285e620b845e09b18939e8d6448e01e692f3ceChris Lattner DenseMap<Value*, unsigned> FactorOccurrences; 74094285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 74194285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // Keep track of each multiply we see, to avoid triggering on (X*4)+(X*4) 74294285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // where they are actually the same multiply. 74394285e620b845e09b18939e8d6448e01e692f3ceChris Lattner unsigned MaxOcc = 0; 74494285e620b845e09b18939e8d6448e01e692f3ceChris Lattner Value *MaxOccVal = 0; 74594285e620b845e09b18939e8d6448e01e692f3ceChris Lattner for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 74694285e620b845e09b18939e8d6448e01e692f3ceChris Lattner BinaryOperator *BOp = dyn_cast<BinaryOperator>(Ops[i].Op); 74794285e620b845e09b18939e8d6448e01e692f3ceChris Lattner if (BOp == 0 || BOp->getOpcode() != Instruction::Mul || !BOp->use_empty()) 74894285e620b845e09b18939e8d6448e01e692f3ceChris Lattner continue; 74994285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 75094285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // Compute all of the factors of this added value. 75194285e620b845e09b18939e8d6448e01e692f3ceChris Lattner SmallVector<Value*, 8> Factors; 75294285e620b845e09b18939e8d6448e01e692f3ceChris Lattner FindSingleUseMultiplyFactors(BOp, Factors); 75394285e620b845e09b18939e8d6448e01e692f3ceChris Lattner assert(Factors.size() > 1 && "Bad linearize!"); 75494285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 75594285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // Add one to FactorOccurrences for each unique factor in this op. 7569506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner SmallPtrSet<Value*, 8> Duplicates; 7579506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner for (unsigned i = 0, e = Factors.size(); i != e; ++i) { 7589506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner Value *Factor = Factors[i]; 7599506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner if (!Duplicates.insert(Factor)) continue; 7609506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner 7619506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner unsigned Occ = ++FactorOccurrences[Factor]; 7629506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner if (Occ > MaxOcc) { MaxOcc = Occ; MaxOccVal = Factor; } 7639506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner 7649506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner // If Factor is a negative constant, add the negated value as a factor 7659506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner // because we can percolate the negate out. Watch for minint, which 7669506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner // cannot be positivified. 7679506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(Factor)) 7689506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner if (CI->getValue().isNegative() && !CI->getValue().isMinSignedValue()) { 7699506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner Factor = ConstantInt::get(CI->getContext(), -CI->getValue()); 7709506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner assert(!Duplicates.count(Factor) && 7719506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner "Shouldn't have two constant factors, missed a canonicalize"); 7729506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner 7739506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner unsigned Occ = ++FactorOccurrences[Factor]; 7749506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner if (Occ > MaxOcc) { MaxOcc = Occ; MaxOccVal = Factor; } 7759506c930aa1f7c5fbf1e0e1e6bfae71f4a61ee15Chris Lattner } 77694285e620b845e09b18939e8d6448e01e692f3ceChris Lattner } 77794285e620b845e09b18939e8d6448e01e692f3ceChris Lattner } 77894285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 77994285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // If any factor occurred more than one time, we can pull it out. 78094285e620b845e09b18939e8d6448e01e692f3ceChris Lattner if (MaxOcc > 1) { 78169e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner DEBUG(errs() << "\nFACTORING [" << MaxOcc << "]: " << *MaxOccVal << '\n'); 78294285e620b845e09b18939e8d6448e01e692f3ceChris Lattner ++NumFactor; 78394285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 78494285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // Create a new instruction that uses the MaxOccVal twice. If we don't do 78594285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // this, we could otherwise run into situations where removing a factor 78694285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // from an expression will drop a use of maxocc, and this can cause 78794285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // RemoveFactorFromExpression on successive values to behave differently. 78894285e620b845e09b18939e8d6448e01e692f3ceChris Lattner Instruction *DummyInst = BinaryOperator::CreateAdd(MaxOccVal, MaxOccVal); 78994285e620b845e09b18939e8d6448e01e692f3ceChris Lattner SmallVector<Value*, 4> NewMulOps; 79094285e620b845e09b18939e8d6448e01e692f3ceChris Lattner for (unsigned i = 0, e = Ops.size(); i != e; ++i) { 79194285e620b845e09b18939e8d6448e01e692f3ceChris Lattner if (Value *V = RemoveFactorFromExpression(Ops[i].Op, MaxOccVal)) { 79294285e620b845e09b18939e8d6448e01e692f3ceChris Lattner NewMulOps.push_back(V); 79394285e620b845e09b18939e8d6448e01e692f3ceChris Lattner Ops.erase(Ops.begin()+i); 79494285e620b845e09b18939e8d6448e01e692f3ceChris Lattner --i; --e; 79594285e620b845e09b18939e8d6448e01e692f3ceChris Lattner } 79694285e620b845e09b18939e8d6448e01e692f3ceChris Lattner } 79794285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 79894285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // No need for extra uses anymore. 79994285e620b845e09b18939e8d6448e01e692f3ceChris Lattner delete DummyInst; 80094285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 80194285e620b845e09b18939e8d6448e01e692f3ceChris Lattner unsigned NumAddedValues = NewMulOps.size(); 80294285e620b845e09b18939e8d6448e01e692f3ceChris Lattner Value *V = EmitAddTreeOfValues(I, NewMulOps); 80394285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 80469e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // Now that we have inserted the add tree, optimize it. This allows us to 80569e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // handle cases that require multiple factoring steps, such as this: 80694285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // A*A*B + A*A*C --> A*(A*B+A*C) --> A*(A*(B+C)) 8079cd1bc4f8b3e98892a2b9856eccd2a2ec9afdf7fChris Lattner assert(NumAddedValues > 1 && "Each occurrence should contribute a value"); 80869e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner V = ReassociateExpression(cast<BinaryOperator>(V)); 80969e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner 81069e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // Create the multiply. 81169e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner Value *V2 = BinaryOperator::CreateMul(V, MaxOccVal, "tmp", I); 81269e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner 813f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner // Rerun associate on the multiply in case the inner expression turned into 814f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner // a multiply. We want to make sure that we keep things in canonical form. 815f31e2e92a801c5053dc9b3b484cdec73ad89e567Chris Lattner V2 = ReassociateExpression(cast<BinaryOperator>(V2)); 81694285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 81794285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // If every add operand included the factor (e.g. "A*B + A*C"), then the 81894285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // entire result expression is just the multiply "A*(B+C)". 81994285e620b845e09b18939e8d6448e01e692f3ceChris Lattner if (Ops.empty()) 82094285e620b845e09b18939e8d6448e01e692f3ceChris Lattner return V2; 82194285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 8229cd1bc4f8b3e98892a2b9856eccd2a2ec9afdf7fChris Lattner // Otherwise, we had some input that didn't have the factor, such as 82394285e620b845e09b18939e8d6448e01e692f3ceChris Lattner // "A*B + A*C + D" -> "A*(B+C) + D". Add the new multiply to the list of 8249cd1bc4f8b3e98892a2b9856eccd2a2ec9afdf7fChris Lattner // things being added by this operation. 82594285e620b845e09b18939e8d6448e01e692f3ceChris Lattner Ops.insert(Ops.begin(), ValueEntry(getRank(V2), V2)); 82694285e620b845e09b18939e8d6448e01e692f3ceChris Lattner } 82794285e620b845e09b18939e8d6448e01e692f3ceChris Lattner 828f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner return 0; 829f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner} 830e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 831e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris LattnerValue *Reassociate::OptimizeExpression(BinaryOperator *I, 8329f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner SmallVectorImpl<ValueEntry> &Ops) { 833469001000620df176decd093a300db84a06cc78bChris Lattner // Now that we have the linearized expression tree, try to optimize it. 834469001000620df176decd093a300db84a06cc78bChris Lattner // Start by folding any constants that we found. 835109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner bool IterateOptimization = false; 836e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner if (Ops.size() == 1) return Ops[0].Op; 837469001000620df176decd093a300db84a06cc78bChris Lattner 838e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner unsigned Opcode = I->getOpcode(); 839e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 840469001000620df176decd093a300db84a06cc78bChris Lattner if (Constant *V1 = dyn_cast<Constant>(Ops[Ops.size()-2].Op)) 841469001000620df176decd093a300db84a06cc78bChris Lattner if (Constant *V2 = dyn_cast<Constant>(Ops.back().Op)) { 842469001000620df176decd093a300db84a06cc78bChris Lattner Ops.pop_back(); 843baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Ops.back().Op = ConstantExpr::get(Opcode, V1, V2); 844e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner return OptimizeExpression(I, Ops); 845469001000620df176decd093a300db84a06cc78bChris Lattner } 846469001000620df176decd093a300db84a06cc78bChris Lattner 847469001000620df176decd093a300db84a06cc78bChris Lattner // Check for destructive annihilation due to a constant being used. 8486b6b6ef1677fa71b1072c2911b4c1f9524a558c9Zhou Sheng if (ConstantInt *CstVal = dyn_cast<ConstantInt>(Ops.back().Op)) 849469001000620df176decd093a300db84a06cc78bChris Lattner switch (Opcode) { 850469001000620df176decd093a300db84a06cc78bChris Lattner default: break; 851469001000620df176decd093a300db84a06cc78bChris Lattner case Instruction::And: 8529046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner if (CstVal->isZero()) // X & 0 -> 0 853e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner return CstVal; 8549046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner if (CstVal->isAllOnesValue()) // X & -1 -> X 8558d93b259f6d6ece634df86d5df453efc0c918546Chris Lattner Ops.pop_back(); 856469001000620df176decd093a300db84a06cc78bChris Lattner break; 857469001000620df176decd093a300db84a06cc78bChris Lattner case Instruction::Mul: 8589046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner if (CstVal->isZero()) { // X * 0 -> 0 859109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner ++NumAnnihil; 860e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner return CstVal; 861469001000620df176decd093a300db84a06cc78bChris Lattner } 8628d93b259f6d6ece634df86d5df453efc0c918546Chris Lattner 8638d93b259f6d6ece634df86d5df453efc0c918546Chris Lattner if (cast<ConstantInt>(CstVal)->isOne()) 8649046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner Ops.pop_back(); // X * 1 -> X 865469001000620df176decd093a300db84a06cc78bChris Lattner break; 866469001000620df176decd093a300db84a06cc78bChris Lattner case Instruction::Or: 8679046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner if (CstVal->isAllOnesValue()) // X | -1 -> -1 868e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner return CstVal; 869469001000620df176decd093a300db84a06cc78bChris Lattner // FALLTHROUGH! 870469001000620df176decd093a300db84a06cc78bChris Lattner case Instruction::Add: 871469001000620df176decd093a300db84a06cc78bChris Lattner case Instruction::Xor: 8729046193e557d559f45dc50df5e20b1fccc90b2acChris Lattner if (CstVal->isZero()) // X [|^+] 0 -> X 873469001000620df176decd093a300db84a06cc78bChris Lattner Ops.pop_back(); 874469001000620df176decd093a300db84a06cc78bChris Lattner break; 875469001000620df176decd093a300db84a06cc78bChris Lattner } 876e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner if (Ops.size() == 1) return Ops[0].Op; 877469001000620df176decd093a300db84a06cc78bChris Lattner 878ec531233a16605756a84d175178e1ee0fac4791cChris Lattner // Handle destructive annihilation due to identities between elements in the 879469001000620df176decd093a300db84a06cc78bChris Lattner // argument list here. 880109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner switch (Opcode) { 881109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner default: break; 882109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner case Instruction::And: 883109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner case Instruction::Or: 884f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner case Instruction::Xor: { 885f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner unsigned NumOps = Ops.size(); 886f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner if (Value *Result = OptimizeAndOrXor(Opcode, Ops)) 887f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner return Result; 888f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner IterateOptimization |= Ops.size() != NumOps; 889109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner break; 890f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner } 891109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner 892f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner case Instruction::Add: { 893f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner unsigned NumOps = Ops.size(); 89494285e620b845e09b18939e8d6448e01e692f3ceChris Lattner if (Value *Result = OptimizeAdd(I, Ops)) 895f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner return Result; 896f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner IterateOptimization |= Ops.size() != NumOps; 897f3f55a9bc1ce62fad7faecff7bd83565d569dee8Chris Lattner } 898e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner 899109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner break; 900109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner //case Instruction::Mul: 901109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner } 902109d34d6ff51a0fdd39d7b3b373a83fcca6c67a3Chris Lattner 90300b16889ab461b7ecef1c91ade101186b7f1fce2Jeff Cohen if (IterateOptimization) 904e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner return OptimizeExpression(I, Ops); 905e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner return 0; 906469001000620df176decd093a300db84a06cc78bChris Lattner} 907469001000620df176decd093a300db84a06cc78bChris Lattner 90808b43921e18f314c4fd38049291d323830934c36Chris Lattner 90908b43921e18f314c4fd38049291d323830934c36Chris Lattner/// ReassociateBB - Inspect all of the instructions in this basic block, 91008b43921e18f314c4fd38049291d323830934c36Chris Lattner/// reassociating them as we go. 911c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattnervoid Reassociate::ReassociateBB(BasicBlock *BB) { 912e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner for (BasicBlock::iterator BBI = BB->begin(); BBI != BB->end(); ) { 913e5022fe4cd83eef91f5c3a21c943ca9b65507ab8Chris Lattner Instruction *BI = BBI++; 914641f02f10f08c9a9add651c6f0169f5441eaeb49Chris Lattner if (BI->getOpcode() == Instruction::Shl && 915641f02f10f08c9a9add651c6f0169f5441eaeb49Chris Lattner isa<ConstantInt>(BI->getOperand(1))) 916e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewycky if (Instruction *NI = ConvertShiftToMul(BI, ValueRankMap)) { 917641f02f10f08c9a9add651c6f0169f5441eaeb49Chris Lattner MadeChange = true; 918641f02f10f08c9a9add651c6f0169f5441eaeb49Chris Lattner BI = NI; 919641f02f10f08c9a9add651c6f0169f5441eaeb49Chris Lattner } 920641f02f10f08c9a9add651c6f0169f5441eaeb49Chris Lattner 9216f156856ca23394122f39d92fe74eec40a1f7c27Chris Lattner // Reject cases where it is pointless to do this. 922e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer if (!isa<BinaryOperator>(BI) || BI->getType()->isFloatingPoint() || 9239d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer isa<VectorType>(BI->getType())) 9246f156856ca23394122f39d92fe74eec40a1f7c27Chris Lattner continue; // Floating point ops are not associative. 9256f156856ca23394122f39d92fe74eec40a1f7c27Chris Lattner 92608b43921e18f314c4fd38049291d323830934c36Chris Lattner // If this is a subtract instruction which is not already in negate form, 92708b43921e18f314c4fd38049291d323830934c36Chris Lattner // see if we can convert it to X+-Y. 928f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner if (BI->getOpcode() == Instruction::Sub) { 929e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewycky if (ShouldBreakUpSubtract(BI)) { 930e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewycky BI = BreakUpSubtract(BI, ValueRankMap); 931d5b8d92b9f4dfb216e4f2a52b4e801d7559574baChris Lattner MadeChange = true; 932fa82b6eba4e1584d7dba291c28fe908272e1e002Owen Anderson } else if (BinaryOperator::isNeg(BI)) { 933f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner // Otherwise, this is a negation. See if the operand is a multiply tree 934f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner // and if this is not an inner node of a multiply tree. 935f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner if (isReassociableOp(BI->getOperand(1), Instruction::Mul) && 936f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner (!BI->hasOneUse() || 937f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner !isReassociableOp(BI->use_back(), Instruction::Mul))) { 938e79fddedcae1ee8fe7d8571db58447bc722f75dcNick Lewycky BI = LowerNegateToMultiply(BI, ValueRankMap); 939f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner MadeChange = true; 940f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner } 94108b43921e18f314c4fd38049291d323830934c36Chris Lattner } 942f33151aff008c40eec6435ddb7a5c9017b6acef9Chris Lattner } 943e4b730441dab4aff9a69aeddbdea98990e7703c4Chris Lattner 944c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // If this instruction is a commutative binary operator, process it. 945c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner if (!BI->isAssociative()) continue; 946c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner BinaryOperator *I = cast<BinaryOperator>(BI); 94700b16889ab461b7ecef1c91ade101186b7f1fce2Jeff Cohen 948c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // If this is an interior node of a reassociable tree, ignore it until we 949c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner // get to the root of the tree, to avoid N^2 analysis. 950c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner if (I->hasOneUse() && isReassociableOp(I->use_back(), I->getOpcode())) 951c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner continue; 952c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner 9537b4ad94282b94e1827be29b4db73fdf6e241f748Chris Lattner // If this is an add tree that is used by a sub instruction, ignore it 9547b4ad94282b94e1827be29b4db73fdf6e241f748Chris Lattner // until we process the subtract. 9557b4ad94282b94e1827be29b4db73fdf6e241f748Chris Lattner if (I->hasOneUse() && I->getOpcode() == Instruction::Add && 9567b4ad94282b94e1827be29b4db73fdf6e241f748Chris Lattner cast<Instruction>(I->use_back())->getOpcode() == Instruction::Sub) 9577b4ad94282b94e1827be29b4db73fdf6e241f748Chris Lattner continue; 9587b4ad94282b94e1827be29b4db73fdf6e241f748Chris Lattner 959895b392269cad07c34d59110d68dc86708c53adbChris Lattner ReassociateExpression(I); 960895b392269cad07c34d59110d68dc86708c53adbChris Lattner } 961895b392269cad07c34d59110d68dc86708c53adbChris Lattner} 962c9fd097a01383323f166c14c17d3984620cad766Chris Lattner 96369e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris LattnerValue *Reassociate::ReassociateExpression(BinaryOperator *I) { 964895b392269cad07c34d59110d68dc86708c53adbChris Lattner 96569e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // First, walk the expression tree, linearizing the tree, collecting the 96669e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // operand information. 9679f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner SmallVector<ValueEntry, 8> Ops; 968895b392269cad07c34d59110d68dc86708c53adbChris Lattner LinearizeExprTree(I, Ops); 969895b392269cad07c34d59110d68dc86708c53adbChris Lattner 97094285e620b845e09b18939e8d6448e01e692f3ceChris Lattner DEBUG(errs() << "RAIn:\t"; PrintOps(I, Ops); errs() << '\n'); 971895b392269cad07c34d59110d68dc86708c53adbChris Lattner 972895b392269cad07c34d59110d68dc86708c53adbChris Lattner // Now that we have linearized the tree to a list and have gathered all of 973895b392269cad07c34d59110d68dc86708c53adbChris Lattner // the operands and their ranks, sort the operands by their rank. Use a 974895b392269cad07c34d59110d68dc86708c53adbChris Lattner // stable_sort so that values with equal ranks will have their relative 975895b392269cad07c34d59110d68dc86708c53adbChris Lattner // positions maintained (and so the compiler is deterministic). Note that 976895b392269cad07c34d59110d68dc86708c53adbChris Lattner // this sorts so that the highest ranking values end up at the beginning of 977895b392269cad07c34d59110d68dc86708c53adbChris Lattner // the vector. 978895b392269cad07c34d59110d68dc86708c53adbChris Lattner std::stable_sort(Ops.begin(), Ops.end()); 979895b392269cad07c34d59110d68dc86708c53adbChris Lattner 980895b392269cad07c34d59110d68dc86708c53adbChris Lattner // OptimizeExpression - Now that we have the expression tree in a convenient 981895b392269cad07c34d59110d68dc86708c53adbChris Lattner // sorted form, optimize it globally if possible. 982895b392269cad07c34d59110d68dc86708c53adbChris Lattner if (Value *V = OptimizeExpression(I, Ops)) { 983895b392269cad07c34d59110d68dc86708c53adbChris Lattner // This expression tree simplified to something that isn't a tree, 984895b392269cad07c34d59110d68dc86708c53adbChris Lattner // eliminate it. 98594285e620b845e09b18939e8d6448e01e692f3ceChris Lattner DEBUG(errs() << "Reassoc to scalar: " << *V << '\n'); 986895b392269cad07c34d59110d68dc86708c53adbChris Lattner I->replaceAllUsesWith(V); 987895b392269cad07c34d59110d68dc86708c53adbChris Lattner RemoveDeadBinaryOp(I); 9889fdaefad580194353f34b6d72669591f8f9d811aChris Lattner ++NumAnnihil; 98969e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner return V; 990895b392269cad07c34d59110d68dc86708c53adbChris Lattner } 991895b392269cad07c34d59110d68dc86708c53adbChris Lattner 992895b392269cad07c34d59110d68dc86708c53adbChris Lattner // We want to sink immediates as deeply as possible except in the case where 993895b392269cad07c34d59110d68dc86708c53adbChris Lattner // this is a multiply tree used only by an add, and the immediate is a -1. 994895b392269cad07c34d59110d68dc86708c53adbChris Lattner // In this case we reassociate to put the negation on the outside so that we 995895b392269cad07c34d59110d68dc86708c53adbChris Lattner // can fold the negation into the add: (-X)*Y + Z -> Z-X*Y 996895b392269cad07c34d59110d68dc86708c53adbChris Lattner if (I->getOpcode() == Instruction::Mul && I->hasOneUse() && 997895b392269cad07c34d59110d68dc86708c53adbChris Lattner cast<Instruction>(I->use_back())->getOpcode() == Instruction::Add && 998895b392269cad07c34d59110d68dc86708c53adbChris Lattner isa<ConstantInt>(Ops.back().Op) && 999895b392269cad07c34d59110d68dc86708c53adbChris Lattner cast<ConstantInt>(Ops.back().Op)->isAllOnesValue()) { 10009f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner ValueEntry Tmp = Ops.pop_back_val(); 10019f7b7089be854c323f8d9a4627d80e47adf496e6Chris Lattner Ops.insert(Ops.begin(), Tmp); 1002895b392269cad07c34d59110d68dc86708c53adbChris Lattner } 1003895b392269cad07c34d59110d68dc86708c53adbChris Lattner 100494285e620b845e09b18939e8d6448e01e692f3ceChris Lattner DEBUG(errs() << "RAOut:\t"; PrintOps(I, Ops); errs() << '\n'); 1005895b392269cad07c34d59110d68dc86708c53adbChris Lattner 1006895b392269cad07c34d59110d68dc86708c53adbChris Lattner if (Ops.size() == 1) { 1007895b392269cad07c34d59110d68dc86708c53adbChris Lattner // This expression tree simplified to something that isn't a tree, 1008895b392269cad07c34d59110d68dc86708c53adbChris Lattner // eliminate it. 1009895b392269cad07c34d59110d68dc86708c53adbChris Lattner I->replaceAllUsesWith(Ops[0].Op); 1010895b392269cad07c34d59110d68dc86708c53adbChris Lattner RemoveDeadBinaryOp(I); 101169e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner return Ops[0].Op; 10124fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner } 101369e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner 101469e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // Now that we ordered and optimized the expressions, splat them back into 101569e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner // the expression tree, removing any unneeded nodes. 101669e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner RewriteExprTree(I, Ops); 101769e98e2c0f7a1a1a8e3547b57e3e78e1142b8a64Chris Lattner return I; 10184fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner} 10194fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 10204fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 10217e70829632f82de15db187845666aaca6e04b792Chris Lattnerbool Reassociate::runOnFunction(Function &F) { 10224fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner // Recalculate the rank map for F 10234fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner BuildRankMap(F); 10244fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 1025c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner MadeChange = false; 10267e70829632f82de15db187845666aaca6e04b792Chris Lattner for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) 1027c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner ReassociateBB(FI); 10284fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner 1029f55e7f54b1877aa6a58b368084cc25acbaa30967Chris Lattner // We are done with the rank map. 10304fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner RankMap.clear(); 1031fb5be090f59997deb7a2e89c92bac19528ba6755Chris Lattner ValueRankMap.clear(); 1032c0649ac931d22b7118c1db292b887cd4eb52cd32Chris Lattner return MadeChange; 10334fd56003ab29e3662c909bb10e47daa97ceb55abChris Lattner} 1034d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 1035