PHITransAddr.cpp revision 43678f41a37c077f28517c2e4889cca88cada6ce
1210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner//===- PHITransAddr.cpp - PHI Translation for Addresses -------------------===// 2210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner// 3210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner// The LLVM Compiler Infrastructure 4210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner// 5210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner// This file is distributed under the University of Illinois Open Source 6210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner// License. See LICENSE.TXT for details. 7210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner// 8210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner//===----------------------------------------------------------------------===// 9210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner// 10210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner// This file implements the PHITransAddr class. 11210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner// 12210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner//===----------------------------------------------------------------------===// 13210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner 14210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner#include "llvm/Analysis/PHITransAddr.h" 15210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner#include "llvm/Analysis/Dominators.h" 169a8641201b2db8427be2a6531c043f384562c081Chris Lattner#include "llvm/Analysis/InstructionSimplify.h" 17210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattnerusing namespace llvm; 18210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner 196fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattnerstatic bool CanPHITrans(Instruction *Inst) { 209a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (isa<PHINode>(Inst) || 219a8641201b2db8427be2a6531c043f384562c081Chris Lattner isa<BitCastInst>(Inst) || 226fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner isa<GetElementPtrInst>(Inst)) 239a8641201b2db8427be2a6531c043f384562c081Chris Lattner return true; 246fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 2534f849098bfb8850fa34fbd115ba9b2e55c85a32Chris Lattner if (Inst->getOpcode() == Instruction::Add && 266fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner isa<ConstantInt>(Inst->getOperand(1))) 276fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return true; 286fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 299a8641201b2db8427be2a6531c043f384562c081Chris Lattner // cerr << "MEMDEP: Could not PHI translate: " << *Pointer; 309a8641201b2db8427be2a6531c043f384562c081Chris Lattner // if (isa<BitCastInst>(PtrInst) || isa<GetElementPtrInst>(PtrInst)) 319a8641201b2db8427be2a6531c043f384562c081Chris Lattner // cerr << "OP:\t\t\t\t" << *PtrInst->getOperand(0); 329a8641201b2db8427be2a6531c043f384562c081Chris Lattner return false; 33210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner} 34210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner 356fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner/// IsPotentiallyPHITranslatable - If this needs PHI translation, return true 366fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner/// if we have some hope of doing it. This should be used as a filter to 376fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner/// avoid calling PHITranslateValue in hopeless situations. 386fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattnerbool PHITransAddr::IsPotentiallyPHITranslatable() const { 396fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // If the input value is not an instruction, or if it is not defined in CurBB, 406fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // then we don't need to phi translate it. 416fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner Instruction *Inst = dyn_cast<Instruction>(Addr); 426fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return Inst == 0 || CanPHITrans(Inst); 436fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner} 446fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 459a8641201b2db8427be2a6531c043f384562c081Chris Lattner 4643678f41a37c077f28517c2e4889cca88cada6ceChris Lattnerstatic void RemoveInstInputs(Instruction *I, 4743678f41a37c077f28517c2e4889cca88cada6ceChris Lattner SmallVectorImpl<Instruction*> &InstInputs) { 4843678f41a37c077f28517c2e4889cca88cada6ceChris Lattner // If the instruction is in the InstInputs list, remove it. 4943678f41a37c077f28517c2e4889cca88cada6ceChris Lattner SmallVectorImpl<Instruction*>::iterator Entry = 5043678f41a37c077f28517c2e4889cca88cada6ceChris Lattner std::find(InstInputs.begin(), InstInputs.end(), I); 5143678f41a37c077f28517c2e4889cca88cada6ceChris Lattner if (Entry != InstInputs.end()) { 5243678f41a37c077f28517c2e4889cca88cada6ceChris Lattner InstInputs.erase(Entry); 5343678f41a37c077f28517c2e4889cca88cada6ceChris Lattner return; 5443678f41a37c077f28517c2e4889cca88cada6ceChris Lattner } 5543678f41a37c077f28517c2e4889cca88cada6ceChris Lattner 5643678f41a37c077f28517c2e4889cca88cada6ceChris Lattner // Otherwise, it must have instruction inputs itself. Zap them recursively. 5743678f41a37c077f28517c2e4889cca88cada6ceChris Lattner bool HadInstInputs = false; 5843678f41a37c077f28517c2e4889cca88cada6ceChris Lattner for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) { 5943678f41a37c077f28517c2e4889cca88cada6ceChris Lattner if (Instruction *Op = dyn_cast<Instruction>(I->getOperand(i))) { 6043678f41a37c077f28517c2e4889cca88cada6ceChris Lattner RemoveInstInputs(Op, InstInputs); 6143678f41a37c077f28517c2e4889cca88cada6ceChris Lattner HadInstInputs = true; 6243678f41a37c077f28517c2e4889cca88cada6ceChris Lattner } 6343678f41a37c077f28517c2e4889cca88cada6ceChris Lattner } 6443678f41a37c077f28517c2e4889cca88cada6ceChris Lattner 6543678f41a37c077f28517c2e4889cca88cada6ceChris Lattner // This instruction had to have operands in the instinputs list or it should 6643678f41a37c077f28517c2e4889cca88cada6ceChris Lattner // have been in the list itself. If not, the list is broken. 6743678f41a37c077f28517c2e4889cca88cada6ceChris Lattner assert(HadInstInputs && "InstInputs list inconsistent!"); 6843678f41a37c077f28517c2e4889cca88cada6ceChris Lattner} 6943678f41a37c077f28517c2e4889cca88cada6ceChris Lattner 7043678f41a37c077f28517c2e4889cca88cada6ceChris Lattner/// ReplaceInstWithValue - Remove any instruction inputs in the InstInputs 7143678f41a37c077f28517c2e4889cca88cada6ceChris Lattner/// array that are due to the specified instruction that is about to be 7243678f41a37c077f28517c2e4889cca88cada6ceChris Lattner/// removed from the address, and add any corresponding to V. This returns V. 7343678f41a37c077f28517c2e4889cca88cada6ceChris LattnerValue *PHITransAddr::ReplaceInstWithValue(Instruction *I, Value *V) { 7443678f41a37c077f28517c2e4889cca88cada6ceChris Lattner // Remove the old instruction from InstInputs. 7543678f41a37c077f28517c2e4889cca88cada6ceChris Lattner RemoveInstInputs(I, InstInputs); 7643678f41a37c077f28517c2e4889cca88cada6ceChris Lattner 7743678f41a37c077f28517c2e4889cca88cada6ceChris Lattner // If V is an instruction, it is now an input. 7843678f41a37c077f28517c2e4889cca88cada6ceChris Lattner if (Instruction *VI = dyn_cast<Instruction>(V)) 7943678f41a37c077f28517c2e4889cca88cada6ceChris Lattner InstInputs.push_back(VI); 8043678f41a37c077f28517c2e4889cca88cada6ceChris Lattner return V; 8143678f41a37c077f28517c2e4889cca88cada6ceChris Lattner} 8243678f41a37c077f28517c2e4889cca88cada6ceChris Lattner 8343678f41a37c077f28517c2e4889cca88cada6ceChris Lattner 849a8641201b2db8427be2a6531c043f384562c081Chris LattnerValue *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, 859a8641201b2db8427be2a6531c043f384562c081Chris Lattner BasicBlock *PredBB) { 869a8641201b2db8427be2a6531c043f384562c081Chris Lattner // If this is a non-instruction value, it can't require PHI translation. 879a8641201b2db8427be2a6531c043f384562c081Chris Lattner Instruction *Inst = dyn_cast<Instruction>(V); 889a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (Inst == 0) return V; 899a8641201b2db8427be2a6531c043f384562c081Chris Lattner 906fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // If 'Inst' is defined in this block, it must be an input that needs to be 916fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // phi translated or an intermediate expression that needs to be incorporated 926fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // into the expression. 936fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (Inst->getParent() == CurBB) { 946fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner assert(std::count(InstInputs.begin(), InstInputs.end(), Inst) && 956fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner "Not an input?"); 966fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 976fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // If this is a PHI, go ahead and translate it. 986fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (PHINode *PN = dyn_cast<PHINode>(Inst)) 996fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return PN->getIncomingValueForBlock(PredBB); 1006fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1016fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1026fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // If this is a non-phi value, and it is analyzable, we can incorporate it 1036fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // into the expression by making all instruction operands be inputs. 1046fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (!CanPHITrans(Inst)) 1056fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return 0; 1066fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1076fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Okay, we can incorporate it, this instruction is no longer an input. 1086fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner InstInputs.erase(std::find(InstInputs.begin(), InstInputs.end(), Inst)); 1096fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1106fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // All instruction operands are now inputs (and of course, they may also be 1116fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // defined in this block, so they may need to be phi translated themselves. 1126fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner for (unsigned i = 0, e = Inst->getNumOperands(); i != e; ++i) 1136fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (Instruction *Op = dyn_cast<Instruction>(Inst->getOperand(i))) 1146fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner InstInputs.push_back(Op); 1156fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1166fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner } else { 1176fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Determine whether 'Inst' is an input to our PHI translatable expression. 1186fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner bool isInput = std::count(InstInputs.begin(), InstInputs.end(), Inst); 1196fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1206fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // If it is an input defined in a different block, then it remains an input. 1219a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (isInput) 1229a8641201b2db8427be2a6531c043f384562c081Chris Lattner return Inst; 1236fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner } 1246fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1256fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Ok, it must be an intermediate result (either because it started that way 1266fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // or because we just incorporated it into the expression). See if its 1276fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // operands need to be phi translated, and if so, reconstruct it. 1289a8641201b2db8427be2a6531c043f384562c081Chris Lattner 1296fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (BitCastInst *BC = dyn_cast<BitCastInst>(Inst)) { 1306fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner Value *PHIIn = PHITranslateSubExpr(BC->getOperand(0), CurBB, PredBB); 1316fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (PHIIn == 0) return 0; 1326fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (PHIIn == BC->getOperand(0)) 1336fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return BC; 1346fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1356fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Find an available version of this cast. 1366fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1376fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Constants are trivial to find. 1386fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (Constant *C = dyn_cast<Constant>(PHIIn)) 13943678f41a37c077f28517c2e4889cca88cada6ceChris Lattner return ReplaceInstWithValue(BC, ConstantExpr::getBitCast(C, 14043678f41a37c077f28517c2e4889cca88cada6ceChris Lattner BC->getType())); 1416fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1426fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Otherwise we have to see if a bitcasted version of the incoming pointer 1436fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // is available. If so, we can use it, otherwise we have to fail. 1446fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner for (Value::use_iterator UI = PHIIn->use_begin(), E = PHIIn->use_end(); 1456fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner UI != E; ++UI) { 1466fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (BitCastInst *BCI = dyn_cast<BitCastInst>(*UI)) 1476fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (BCI->getType() == BC->getType()) 1486fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return BCI; 1496fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner } 1506fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return 0; 1516fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner } 1526fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1536fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Handle getelementptr with at least one PHI translatable operand. 1546fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Inst)) { 1556fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner SmallVector<Value*, 8> GEPOps; 1566fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner BasicBlock *CurBB = GEP->getParent(); 1576fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner bool AnyChanged = false; 1586fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner for (unsigned i = 0, e = GEP->getNumOperands(); i != e; ++i) { 1596fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner Value *GEPOp = PHITranslateSubExpr(GEP->getOperand(i), CurBB, PredBB); 1606fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (GEPOp == 0) return 0; 1619a8641201b2db8427be2a6531c043f384562c081Chris Lattner 1626045417fcc21b1c0663120b9f24ec822f5d17cfeChris Lattner AnyChanged |= GEPOp != GEP->getOperand(i); 1636fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner GEPOps.push_back(GEPOp); 1649a8641201b2db8427be2a6531c043f384562c081Chris Lattner } 1659a8641201b2db8427be2a6531c043f384562c081Chris Lattner 1666fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (!AnyChanged) 1676fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return GEP; 1686fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1696fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Simplify the GEP to handle 'gep x, 0' -> x etc. 1706fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (Value *V = SimplifyGEPInst(&GEPOps[0], GEPOps.size(), TD)) 17143678f41a37c077f28517c2e4889cca88cada6ceChris Lattner return ReplaceInstWithValue(GEP, V); 1726fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1736fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Scan to see if we have this GEP available. 1746fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner Value *APHIOp = GEPOps[0]; 1756fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner for (Value::use_iterator UI = APHIOp->use_begin(), E = APHIOp->use_end(); 1766fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner UI != E; ++UI) { 1776fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(*UI)) 1786fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (GEPI->getType() == GEP->getType() && 1796fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner GEPI->getNumOperands() == GEPOps.size() && 1806fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner GEPI->getParent()->getParent() == CurBB->getParent()) { 1816fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner bool Mismatch = false; 1826fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner for (unsigned i = 0, e = GEPOps.size(); i != e; ++i) 1836fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (GEPI->getOperand(i) != GEPOps[i]) { 1846fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner Mismatch = true; 1856fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner break; 1866fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner } 1876fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (!Mismatch) 1886fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return GEPI; 1896fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner } 1909a8641201b2db8427be2a6531c043f384562c081Chris Lattner } 1916fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return 0; 1926fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner } 1936fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 1946fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Handle add with a constant RHS. 1956fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (Inst->getOpcode() == Instruction::Add && 1966fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner isa<ConstantInt>(Inst->getOperand(1))) { 1976fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // PHI translate the LHS. 1986fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner Constant *RHS = cast<ConstantInt>(Inst->getOperand(1)); 1996fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner bool isNSW = cast<BinaryOperator>(Inst)->hasNoSignedWrap(); 2006fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner bool isNUW = cast<BinaryOperator>(Inst)->hasNoUnsignedWrap(); 2019a8641201b2db8427be2a6531c043f384562c081Chris Lattner 2026fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner Value *LHS = PHITranslateSubExpr(Inst->getOperand(0), CurBB, PredBB); 2036fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (LHS == 0) return 0; 2046fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 2056fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // If the PHI translated LHS is an add of a constant, fold the immediates. 2066fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (BinaryOperator *BOp = dyn_cast<BinaryOperator>(LHS)) 2076fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (BOp->getOpcode() == Instruction::Add) 2086fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(BOp->getOperand(1))) { 2096fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner LHS = BOp->getOperand(0); 2106fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner RHS = ConstantExpr::getAdd(RHS, CI); 2116fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner isNSW = isNUW = false; 2126fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner } 2136fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 2146fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // See if the add simplifies away. 2156fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (Value *Res = SimplifyAddInst(LHS, RHS, isNSW, isNUW, TD)) 21643678f41a37c077f28517c2e4889cca88cada6ceChris Lattner return ReplaceInstWithValue(Inst, Res); 2176fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner 2186fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Otherwise, see if we have this add available somewhere. 2196fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner for (Value::use_iterator UI = LHS->use_begin(), E = LHS->use_end(); 2206fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner UI != E; ++UI) { 2216fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (BinaryOperator *BO = dyn_cast<BinaryOperator>(*UI)) 2226fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner if (BO->getOperand(0) == LHS && BO->getOperand(1) == RHS && 2236fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner BO->getParent()->getParent() == CurBB->getParent()) 2246fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return BO; 2259a8641201b2db8427be2a6531c043f384562c081Chris Lattner } 2269a8641201b2db8427be2a6531c043f384562c081Chris Lattner 2279a8641201b2db8427be2a6531c043f384562c081Chris Lattner return 0; 2289a8641201b2db8427be2a6531c043f384562c081Chris Lattner } 2299a8641201b2db8427be2a6531c043f384562c081Chris Lattner 2306fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner // Otherwise, we failed. 2316fcca1cc874c2b374b05399be92c5c1ea2086cc0Chris Lattner return 0; 232210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner} 233210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner 2349a8641201b2db8427be2a6531c043f384562c081Chris Lattner 2359a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// PHITranslateValue - PHI translate the current address up the CFG from 2369a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// CurBB to Pred, updating our state the reflect any needed changes. This 237e05a188cd630448cc25143ee8e69a36ab2e69544Chris Lattner/// returns true on failure and sets Addr to null. 2389a8641201b2db8427be2a6531c043f384562c081Chris Lattnerbool PHITransAddr::PHITranslateValue(BasicBlock *CurBB, BasicBlock *PredBB) { 2399a8641201b2db8427be2a6531c043f384562c081Chris Lattner Addr = PHITranslateSubExpr(Addr, CurBB, PredBB); 2409a8641201b2db8427be2a6531c043f384562c081Chris Lattner return Addr == 0; 2419a8641201b2db8427be2a6531c043f384562c081Chris Lattner} 2429a8641201b2db8427be2a6531c043f384562c081Chris Lattner 2439a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// GetAvailablePHITranslatedSubExpr - Return the value computed by 2449a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// PHITranslateSubExpr if it dominates PredBB, otherwise return null. 245210e45af3a579beeefb001c8f13c94e80407aad5Chris LattnerValue *PHITransAddr:: 2469a8641201b2db8427be2a6531c043f384562c081Chris LattnerGetAvailablePHITranslatedSubExpr(Value *V, BasicBlock *CurBB,BasicBlock *PredBB, 24734f849098bfb8850fa34fbd115ba9b2e55c85a32Chris Lattner const DominatorTree &DT) const { 24834f849098bfb8850fa34fbd115ba9b2e55c85a32Chris Lattner PHITransAddr Tmp(V, TD); 24934f849098bfb8850fa34fbd115ba9b2e55c85a32Chris Lattner Tmp.PHITranslateValue(CurBB, PredBB); 25034f849098bfb8850fa34fbd115ba9b2e55c85a32Chris Lattner 251210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner // See if PHI translation succeeds. 25234f849098bfb8850fa34fbd115ba9b2e55c85a32Chris Lattner V = Tmp.getAddr(); 253210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner 254210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner // Make sure the value is live in the predecessor. 255210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner if (Instruction *Inst = dyn_cast_or_null<Instruction>(V)) 256210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner if (!DT.dominates(Inst->getParent(), PredBB)) 257210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner return 0; 258210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner return V; 259210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner} 260210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner 2619a8641201b2db8427be2a6531c043f384562c081Chris Lattner 2629a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// PHITranslateWithInsertion - PHI translate this value into the specified 2639a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// predecessor block, inserting a computation of the value if it is 2649a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// unavailable. 2659a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// 2669a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// All newly created instructions are added to the NewInsts list. This 2679a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// returns null on failure. 2689a8641201b2db8427be2a6531c043f384562c081Chris Lattner/// 2699a8641201b2db8427be2a6531c043f384562c081Chris LattnerValue *PHITransAddr:: 2709a8641201b2db8427be2a6531c043f384562c081Chris LattnerPHITranslateWithInsertion(BasicBlock *CurBB, BasicBlock *PredBB, 2719a8641201b2db8427be2a6531c043f384562c081Chris Lattner const DominatorTree &DT, 2729a8641201b2db8427be2a6531c043f384562c081Chris Lattner SmallVectorImpl<Instruction*> &NewInsts) { 2739a8641201b2db8427be2a6531c043f384562c081Chris Lattner unsigned NISize = NewInsts.size(); 2749a8641201b2db8427be2a6531c043f384562c081Chris Lattner 2759a8641201b2db8427be2a6531c043f384562c081Chris Lattner // Attempt to PHI translate with insertion. 2769a8641201b2db8427be2a6531c043f384562c081Chris Lattner Addr = InsertPHITranslatedSubExpr(Addr, CurBB, PredBB, DT, NewInsts); 2779a8641201b2db8427be2a6531c043f384562c081Chris Lattner 2789a8641201b2db8427be2a6531c043f384562c081Chris Lattner // If successful, return the new value. 2799a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (Addr) return Addr; 2809a8641201b2db8427be2a6531c043f384562c081Chris Lattner 2819a8641201b2db8427be2a6531c043f384562c081Chris Lattner // If not, destroy any intermediate instructions inserted. 2829a8641201b2db8427be2a6531c043f384562c081Chris Lattner while (NewInsts.size() != NISize) 2839a8641201b2db8427be2a6531c043f384562c081Chris Lattner NewInsts.pop_back_val()->eraseFromParent(); 2849a8641201b2db8427be2a6531c043f384562c081Chris Lattner return 0; 2859a8641201b2db8427be2a6531c043f384562c081Chris Lattner} 2869a8641201b2db8427be2a6531c043f384562c081Chris Lattner 2879a8641201b2db8427be2a6531c043f384562c081Chris Lattner 288210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner/// InsertPHITranslatedPointer - Insert a computation of the PHI translated 289210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner/// version of 'V' for the edge PredBB->CurBB into the end of the PredBB 290210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner/// block. All newly created instructions are added to the NewInsts list. 291210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner/// This returns null on failure. 292210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner/// 293210e45af3a579beeefb001c8f13c94e80407aad5Chris LattnerValue *PHITransAddr:: 2949a8641201b2db8427be2a6531c043f384562c081Chris LattnerInsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, 2959a8641201b2db8427be2a6531c043f384562c081Chris Lattner BasicBlock *PredBB, const DominatorTree &DT, 2969a8641201b2db8427be2a6531c043f384562c081Chris Lattner SmallVectorImpl<Instruction*> &NewInsts) { 297210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner // See if we have a version of this value already available and dominating 2989a8641201b2db8427be2a6531c043f384562c081Chris Lattner // PredBB. If so, there is no need to insert a new instance of it. 2999a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (Value *Res = GetAvailablePHITranslatedSubExpr(InVal, CurBB, PredBB, DT)) 300210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner return Res; 301210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner 3029a8641201b2db8427be2a6531c043f384562c081Chris Lattner // If we don't have an available version of this value, it must be an 3039a8641201b2db8427be2a6531c043f384562c081Chris Lattner // instruction. 3049a8641201b2db8427be2a6531c043f384562c081Chris Lattner Instruction *Inst = cast<Instruction>(InVal); 3059a8641201b2db8427be2a6531c043f384562c081Chris Lattner 3069a8641201b2db8427be2a6531c043f384562c081Chris Lattner // Handle bitcast of PHI translatable value. 3079a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (BitCastInst *BC = dyn_cast<BitCastInst>(Inst)) { 3089a8641201b2db8427be2a6531c043f384562c081Chris Lattner Value *OpVal = InsertPHITranslatedSubExpr(BC->getOperand(0), 3099a8641201b2db8427be2a6531c043f384562c081Chris Lattner CurBB, PredBB, DT, NewInsts); 3109a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (OpVal == 0) return 0; 3119a8641201b2db8427be2a6531c043f384562c081Chris Lattner 3129a8641201b2db8427be2a6531c043f384562c081Chris Lattner // Otherwise insert a bitcast at the end of PredBB. 3139a8641201b2db8427be2a6531c043f384562c081Chris Lattner BitCastInst *New = new BitCastInst(OpVal, InVal->getType(), 3149a8641201b2db8427be2a6531c043f384562c081Chris Lattner InVal->getName()+".phi.trans.insert", 3159a8641201b2db8427be2a6531c043f384562c081Chris Lattner PredBB->getTerminator()); 3169a8641201b2db8427be2a6531c043f384562c081Chris Lattner NewInsts.push_back(New); 3179a8641201b2db8427be2a6531c043f384562c081Chris Lattner return New; 3189a8641201b2db8427be2a6531c043f384562c081Chris Lattner } 3199a8641201b2db8427be2a6531c043f384562c081Chris Lattner 3209a8641201b2db8427be2a6531c043f384562c081Chris Lattner // Handle getelementptr with at least one PHI operand. 3219a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Inst)) { 3229a8641201b2db8427be2a6531c043f384562c081Chris Lattner SmallVector<Value*, 8> GEPOps; 3239a8641201b2db8427be2a6531c043f384562c081Chris Lattner BasicBlock *CurBB = GEP->getParent(); 3249a8641201b2db8427be2a6531c043f384562c081Chris Lattner for (unsigned i = 0, e = GEP->getNumOperands(); i != e; ++i) { 3259a8641201b2db8427be2a6531c043f384562c081Chris Lattner Value *OpVal = InsertPHITranslatedSubExpr(GEP->getOperand(i), 3269a8641201b2db8427be2a6531c043f384562c081Chris Lattner CurBB, PredBB, DT, NewInsts); 3279a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (OpVal == 0) return 0; 3289a8641201b2db8427be2a6531c043f384562c081Chris Lattner GEPOps.push_back(OpVal); 3299a8641201b2db8427be2a6531c043f384562c081Chris Lattner } 3309a8641201b2db8427be2a6531c043f384562c081Chris Lattner 3319a8641201b2db8427be2a6531c043f384562c081Chris Lattner GetElementPtrInst *Result = 3329a8641201b2db8427be2a6531c043f384562c081Chris Lattner GetElementPtrInst::Create(GEPOps[0], GEPOps.begin()+1, GEPOps.end(), 3339a8641201b2db8427be2a6531c043f384562c081Chris Lattner InVal->getName()+".phi.trans.insert", 3349a8641201b2db8427be2a6531c043f384562c081Chris Lattner PredBB->getTerminator()); 3359a8641201b2db8427be2a6531c043f384562c081Chris Lattner Result->setIsInBounds(GEP->isInBounds()); 3369a8641201b2db8427be2a6531c043f384562c081Chris Lattner NewInsts.push_back(Result); 3379a8641201b2db8427be2a6531c043f384562c081Chris Lattner return Result; 3389a8641201b2db8427be2a6531c043f384562c081Chris Lattner } 3399a8641201b2db8427be2a6531c043f384562c081Chris Lattner 3409a8641201b2db8427be2a6531c043f384562c081Chris Lattner#if 0 3419a8641201b2db8427be2a6531c043f384562c081Chris Lattner // FIXME: This code works, but it is unclear that we actually want to insert 3429a8641201b2db8427be2a6531c043f384562c081Chris Lattner // a big chain of computation in order to make a value available in a block. 3439a8641201b2db8427be2a6531c043f384562c081Chris Lattner // This needs to be evaluated carefully to consider its cost trade offs. 3449a8641201b2db8427be2a6531c043f384562c081Chris Lattner 3459a8641201b2db8427be2a6531c043f384562c081Chris Lattner // Handle add with a constant RHS. 3469a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (Inst->getOpcode() == Instruction::Add && 3479a8641201b2db8427be2a6531c043f384562c081Chris Lattner isa<ConstantInt>(Inst->getOperand(1))) { 3489a8641201b2db8427be2a6531c043f384562c081Chris Lattner // PHI translate the LHS. 3499a8641201b2db8427be2a6531c043f384562c081Chris Lattner Value *OpVal = InsertPHITranslatedSubExpr(Inst->getOperand(0), 3509a8641201b2db8427be2a6531c043f384562c081Chris Lattner CurBB, PredBB, DT, NewInsts); 3519a8641201b2db8427be2a6531c043f384562c081Chris Lattner if (OpVal == 0) return 0; 3529a8641201b2db8427be2a6531c043f384562c081Chris Lattner 3539a8641201b2db8427be2a6531c043f384562c081Chris Lattner BinaryOperator *Res = BinaryOperator::CreateAdd(OpVal, Inst->getOperand(1), 3549a8641201b2db8427be2a6531c043f384562c081Chris Lattner InVal->getName()+".phi.trans.insert", 3559a8641201b2db8427be2a6531c043f384562c081Chris Lattner PredBB->getTerminator()); 3569a8641201b2db8427be2a6531c043f384562c081Chris Lattner Res->setHasNoSignedWrap(cast<BinaryOperator>(Inst)->hasNoSignedWrap()); 3579a8641201b2db8427be2a6531c043f384562c081Chris Lattner Res->setHasNoUnsignedWrap(cast<BinaryOperator>(Inst)->hasNoUnsignedWrap()); 3589a8641201b2db8427be2a6531c043f384562c081Chris Lattner NewInsts.push_back(Res); 3599a8641201b2db8427be2a6531c043f384562c081Chris Lattner return Res; 3609a8641201b2db8427be2a6531c043f384562c081Chris Lattner } 3619a8641201b2db8427be2a6531c043f384562c081Chris Lattner#endif 3629a8641201b2db8427be2a6531c043f384562c081Chris Lattner 363210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner return 0; 364210e45af3a579beeefb001c8f13c94e80407aad5Chris Lattner} 365