X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FPHITransAddr.cpp;h=eeea1a3eeff709cf942a436f54e1533f4ac7d079;hb=b9b369fa9983843c4ed77b3a35b6e9b7933955bb;hp=96081112493d4128c0782899c33252d6b1dbef39;hpb=88fc03c461276f56a2005808cf10faa4cd857e5c;p=oota-llvm.git diff --git a/lib/Analysis/PHITransAddr.cpp b/lib/Analysis/PHITransAddr.cpp index 96081112493..eeea1a3eeff 100644 --- a/lib/Analysis/PHITransAddr.cpp +++ b/lib/Analysis/PHITransAddr.cpp @@ -27,11 +27,11 @@ static bool CanPHITrans(Instruction *Inst) { if (isa(Inst) && Inst->isSafeToSpeculativelyExecute()) return true; - + if (Inst->getOpcode() == Instruction::Add && isa(Inst->getOperand(1))) return true; - + // cerr << "MEMDEP: Could not PHI translate: " << *Pointer; // if (isa(PtrInst) || isa(PtrInst)) // cerr << "OP:\t\t\t\t" << *PtrInst->getOperand(0); @@ -54,7 +54,7 @@ static bool VerifySubExpr(Value *Expr, // If this is a non-instruction value, there is nothing to do. Instruction *I = dyn_cast(Expr); if (I == 0) return true; - + // If it's an instruction, it is either in Tmp or its operands recursively // are. SmallVectorImpl::iterator Entry = @@ -63,7 +63,7 @@ static bool VerifySubExpr(Value *Expr, InstInputs.erase(Entry); return true; } - + // If it isn't in the InstInputs list it is a subexpr incorporated into the // address. Sanity check that it is phi translatable. if (!CanPHITrans(I)) { @@ -73,7 +73,7 @@ static bool VerifySubExpr(Value *Expr, "CanPHITrans is wrong."); return false; } - + // Validate the operands of the instruction. for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) if (!VerifySubExpr(I->getOperand(i), InstInputs)) @@ -87,12 +87,12 @@ static bool VerifySubExpr(Value *Expr, /// returns false. bool PHITransAddr::Verify() const { if (Addr == 0) return true; - - SmallVector Tmp(InstInputs.begin(), InstInputs.end()); - + + SmallVector Tmp(InstInputs.begin(), InstInputs.end()); + if (!VerifySubExpr(Addr, Tmp)) return false; - + if (!Tmp.empty()) { errs() << "PHITransAddr contains extra instructions:\n"; for (unsigned i = 0, e = InstInputs.size(); i != e; ++i) @@ -100,7 +100,7 @@ bool PHITransAddr::Verify() const { llvm_unreachable("This is unexpected."); return false; } - + // a-ok. return true; } @@ -117,11 +117,11 @@ bool PHITransAddr::IsPotentiallyPHITranslatable() const { } -static void RemoveInstInputs(Value *V, +static void RemoveInstInputs(Value *V, SmallVectorImpl &InstInputs) { Instruction *I = dyn_cast(V); if (I == 0) return; - + // If the instruction is in the InstInputs list, remove it. SmallVectorImpl::iterator Entry = std::find(InstInputs.begin(), InstInputs.end(), I); @@ -129,9 +129,9 @@ static void RemoveInstInputs(Value *V, InstInputs.erase(Entry); return; } - + assert(!isa(I) && "Error, removing something that isn't an input"); - + // Otherwise, it must have instruction inputs itself. Zap them recursively. for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) { if (Instruction *Op = dyn_cast(I->getOperand(i))) @@ -145,7 +145,7 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, // If this is a non-instruction value, it can't require PHI translation. Instruction *Inst = dyn_cast(V); if (Inst == 0) return V; - + // Determine whether 'Inst' is an input to our PHI translatable expression. bool isInput = std::count(InstInputs.begin(), InstInputs.end(), Inst); @@ -162,16 +162,16 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, // In either case, the instruction itself isn't an input any longer. InstInputs.erase(std::find(InstInputs.begin(), InstInputs.end(), Inst)); - + // If this is a PHI, go ahead and translate it. if (PHINode *PN = dyn_cast(Inst)) return AddAsInput(PN->getIncomingValueForBlock(PredBB)); - + // If this is a non-phi value, and it is analyzable, we can incorporate it // into the expression by making all instruction operands be inputs. if (!CanPHITrans(Inst)) return 0; - + // All instruction operands are now inputs (and of course, they may also be // defined in this block, so they may need to be phi translated themselves. for (unsigned i = 0, e = Inst->getNumOperands(); i != e; ++i) @@ -182,21 +182,21 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, // Ok, it must be an intermediate result (either because it started that way // or because we just incorporated it into the expression). See if its // operands need to be phi translated, and if so, reconstruct it. - + if (CastInst *Cast = dyn_cast(Inst)) { if (!Cast->isSafeToSpeculativelyExecute()) return 0; Value *PHIIn = PHITranslateSubExpr(Cast->getOperand(0), CurBB, PredBB, DT); if (PHIIn == 0) return 0; if (PHIIn == Cast->getOperand(0)) return Cast; - + // Find an available version of this cast. - + // Constants are trivial to find. if (Constant *C = dyn_cast(PHIIn)) return AddAsInput(ConstantExpr::getCast(Cast->getOpcode(), C, Cast->getType())); - + // Otherwise we have to see if a casted version of the incoming pointer // is available. If so, we can use it, otherwise we have to fail. for (Value::use_iterator UI = PHIIn->use_begin(), E = PHIIn->use_end(); @@ -209,7 +209,7 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, } return 0; } - + // Handle getelementptr with at least one PHI translatable operand. if (GetElementPtrInst *GEP = dyn_cast(Inst)) { SmallVector GEPOps; @@ -217,22 +217,22 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, for (unsigned i = 0, e = GEP->getNumOperands(); i != e; ++i) { Value *GEPOp = PHITranslateSubExpr(GEP->getOperand(i), CurBB, PredBB, DT); if (GEPOp == 0) return 0; - + AnyChanged |= GEPOp != GEP->getOperand(i); GEPOps.push_back(GEPOp); } - + if (!AnyChanged) return GEP; - + // Simplify the GEP to handle 'gep x, 0' -> x etc. if (Value *V = SimplifyGEPInst(&GEPOps[0], GEPOps.size(), TD, DT)) { for (unsigned i = 0, e = GEPOps.size(); i != e; ++i) RemoveInstInputs(GEPOps[i], InstInputs); - + return AddAsInput(V); } - + // Scan to see if we have this GEP available. Value *APHIOp = GEPOps[0]; for (Value::use_iterator UI = APHIOp->use_begin(), E = APHIOp->use_end(); @@ -254,7 +254,7 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, } return 0; } - + // Handle add with a constant RHS. if (Inst->getOpcode() == Instruction::Add && isa(Inst->getOperand(1))) { @@ -262,10 +262,10 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, Constant *RHS = cast(Inst->getOperand(1)); bool isNSW = cast(Inst)->hasNoSignedWrap(); bool isNUW = cast(Inst)->hasNoUnsignedWrap(); - + Value *LHS = PHITranslateSubExpr(Inst->getOperand(0), CurBB, PredBB, DT); if (LHS == 0) return 0; - + // If the PHI translated LHS is an add of a constant, fold the immediates. if (BinaryOperator *BOp = dyn_cast(LHS)) if (BOp->getOpcode() == Instruction::Add) @@ -273,14 +273,14 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, LHS = BOp->getOperand(0); RHS = ConstantExpr::getAdd(RHS, CI); isNSW = isNUW = false; - + // If the old 'LHS' was an input, add the new 'LHS' as an input. if (std::count(InstInputs.begin(), InstInputs.end(), BOp)) { RemoveInstInputs(BOp, InstInputs); AddAsInput(LHS); } } - + // See if the add simplifies away. if (Value *Res = SimplifyAddInst(LHS, RHS, isNSW, isNUW, TD, DT)) { // If we simplified the operands, the LHS is no longer an input, but Res @@ -292,7 +292,7 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, // If we didn't modify the add, just return it. if (LHS == Inst->getOperand(0) && RHS == Inst->getOperand(1)) return Inst; - + // Otherwise, see if we have this add available somewhere. for (Value::use_iterator UI = LHS->use_begin(), E = LHS->use_end(); UI != E; ++UI) { @@ -303,10 +303,10 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, (!DT || DT->dominates(BO->getParent(), PredBB))) return BO; } - + return 0; } - + // Otherwise, we failed. return 0; } @@ -344,13 +344,13 @@ PHITranslateWithInsertion(BasicBlock *CurBB, BasicBlock *PredBB, const DominatorTree &DT, SmallVectorImpl &NewInsts) { unsigned NISize = NewInsts.size(); - + // Attempt to PHI translate with insertion. Addr = InsertPHITranslatedSubExpr(Addr, CurBB, PredBB, DT, NewInsts); - + // If successful, return the new value. if (Addr) return Addr; - + // If not, destroy any intermediate instructions inserted. while (NewInsts.size() != NISize) NewInsts.pop_back_val()->eraseFromParent(); @@ -376,14 +376,14 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, // If we don't have an available version of this value, it must be an // instruction. Instruction *Inst = cast(InVal); - + // Handle cast of PHI translatable value. if (CastInst *Cast = dyn_cast(Inst)) { if (!Cast->isSafeToSpeculativelyExecute()) return 0; Value *OpVal = InsertPHITranslatedSubExpr(Cast->getOperand(0), CurBB, PredBB, DT, NewInsts); if (OpVal == 0) return 0; - + // Otherwise insert a cast at the end of PredBB. CastInst *New = CastInst::Create(Cast->getOpcode(), OpVal, InVal->getType(), @@ -392,7 +392,7 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, NewInsts.push_back(New); return New; } - + // Handle getelementptr with at least one PHI operand. if (GetElementPtrInst *GEP = dyn_cast(Inst)) { SmallVector GEPOps; @@ -403,8 +403,8 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, if (OpVal == 0) return 0; GEPOps.push_back(OpVal); } - - GetElementPtrInst *Result = + + GetElementPtrInst *Result = GetElementPtrInst::Create(GEPOps[0], GEPOps.begin()+1, GEPOps.end(), InVal->getName()+".phi.trans.insert", PredBB->getTerminator()); @@ -412,12 +412,12 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, NewInsts.push_back(Result); return Result; } - + #if 0 // FIXME: This code works, but it is unclear that we actually want to insert // a big chain of computation in order to make a value available in a block. // This needs to be evaluated carefully to consider its cost trade offs. - + // Handle add with a constant RHS. if (Inst->getOpcode() == Instruction::Add && isa(Inst->getOperand(1))) { @@ -425,7 +425,7 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, Value *OpVal = InsertPHITranslatedSubExpr(Inst->getOperand(0), CurBB, PredBB, DT, NewInsts); if (OpVal == 0) return 0; - + BinaryOperator *Res = BinaryOperator::CreateAdd(OpVal, Inst->getOperand(1), InVal->getName()+".phi.trans.insert", PredBB->getTerminator()); @@ -435,6 +435,6 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, return Res; } #endif - + return 0; }