diff options
Diffstat (limited to 'contrib/llvm/lib/Analysis/PHITransAddr.cpp')
| -rw-r--r-- | contrib/llvm/lib/Analysis/PHITransAddr.cpp | 154 |
1 files changed, 83 insertions, 71 deletions
diff --git a/contrib/llvm/lib/Analysis/PHITransAddr.cpp b/contrib/llvm/lib/Analysis/PHITransAddr.cpp index 8e4fa03..93da5a4 100644 --- a/contrib/llvm/lib/Analysis/PHITransAddr.cpp +++ b/contrib/llvm/lib/Analysis/PHITransAddr.cpp @@ -12,22 +12,27 @@ //===----------------------------------------------------------------------===// #include "llvm/Analysis/PHITransAddr.h" +#include "llvm/Instructions.h" #include "llvm/Analysis/Dominators.h" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" using namespace llvm; static bool CanPHITrans(Instruction *Inst) { if (isa<PHINode>(Inst) || - isa<BitCastInst>(Inst) || isa<GetElementPtrInst>(Inst)) return true; - + + if (isa<CastInst>(Inst) && + Inst->isSafeToSpeculativelyExecute()) + return true; + if (Inst->getOpcode() == Instruction::Add && isa<ConstantInt>(Inst->getOperand(1))) return true; - + // cerr << "MEMDEP: Could not PHI translate: " << *Pointer; // if (isa<BitCastInst>(PtrInst) || isa<GetElementPtrInst>(PtrInst)) // cerr << "OP:\t\t\t\t" << *PtrInst->getOperand(0); @@ -50,7 +55,7 @@ static bool VerifySubExpr(Value *Expr, // If this is a non-instruction value, there is nothing to do. Instruction *I = dyn_cast<Instruction>(Expr); if (I == 0) return true; - + // If it's an instruction, it is either in Tmp or its operands recursively // are. SmallVectorImpl<Instruction*>::iterator Entry = @@ -59,16 +64,17 @@ 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)) { - errs() << "Non phi translatable instruction found in PHITransAddr, either " - "something is missing from InstInputs or CanPHITrans is wrong:\n"; + errs() << "Non phi translatable instruction found in PHITransAddr:\n"; errs() << *I << '\n'; + llvm_unreachable("Either something is missing from InstInputs or " + "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)) @@ -82,19 +88,20 @@ static bool VerifySubExpr(Value *Expr, /// returns false. bool PHITransAddr::Verify() const { if (Addr == 0) return true; - - SmallVector<Instruction*, 8> Tmp(InstInputs.begin(), InstInputs.end()); - + + SmallVector<Instruction*, 8> Tmp(InstInputs.begin(), InstInputs.end()); + if (!VerifySubExpr(Addr, Tmp)) return false; - + if (!Tmp.empty()) { - errs() << "PHITransAddr inconsistent, contains extra instructions:\n"; + errs() << "PHITransAddr contains extra instructions:\n"; for (unsigned i = 0, e = InstInputs.size(); i != e; ++i) errs() << " InstInput #" << i << " is " << *InstInputs[i] << "\n"; + llvm_unreachable("This is unexpected."); return false; } - + // a-ok. return true; } @@ -111,11 +118,11 @@ bool PHITransAddr::IsPotentiallyPHITranslatable() const { } -static void RemoveInstInputs(Value *V, +static void RemoveInstInputs(Value *V, SmallVectorImpl<Instruction*> &InstInputs) { Instruction *I = dyn_cast<Instruction>(V); if (I == 0) return; - + // If the instruction is in the InstInputs list, remove it. SmallVectorImpl<Instruction*>::iterator Entry = std::find(InstInputs.begin(), InstInputs.end(), I); @@ -123,9 +130,9 @@ static void RemoveInstInputs(Value *V, InstInputs.erase(Entry); return; } - + assert(!isa<PHINode>(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<Instruction>(I->getOperand(i))) @@ -139,7 +146,7 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, // If this is a non-instruction value, it can't require PHI translation. Instruction *Inst = dyn_cast<Instruction>(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); @@ -156,16 +163,16 @@ 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<PHINode>(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) @@ -176,31 +183,34 @@ 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 (BitCastInst *BC = dyn_cast<BitCastInst>(Inst)) { - Value *PHIIn = PHITranslateSubExpr(BC->getOperand(0), CurBB, PredBB, DT); + + if (CastInst *Cast = dyn_cast<CastInst>(Inst)) { + if (!Cast->isSafeToSpeculativelyExecute()) return 0; + Value *PHIIn = PHITranslateSubExpr(Cast->getOperand(0), CurBB, PredBB, DT); if (PHIIn == 0) return 0; - if (PHIIn == BC->getOperand(0)) - return BC; - + if (PHIIn == Cast->getOperand(0)) + return Cast; + // Find an available version of this cast. - + // Constants are trivial to find. if (Constant *C = dyn_cast<Constant>(PHIIn)) - return AddAsInput(ConstantExpr::getBitCast(C, BC->getType())); - - // Otherwise we have to see if a bitcasted version of the incoming pointer + 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(); UI != E; ++UI) { - if (BitCastInst *BCI = dyn_cast<BitCastInst>(*UI)) - if (BCI->getType() == BC->getType() && - (!DT || DT->dominates(BCI->getParent(), PredBB))) - return BCI; + if (CastInst *CastI = dyn_cast<CastInst>(*UI)) + if (CastI->getOpcode() == Cast->getOpcode() && + CastI->getType() == Cast->getType() && + (!DT || DT->dominates(CastI->getParent(), PredBB))) + return CastI; } return 0; } - + // Handle getelementptr with at least one PHI translatable operand. if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Inst)) { SmallVector<Value*, 8> GEPOps; @@ -208,22 +218,22 @@ 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)) { + 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(); @@ -245,7 +255,7 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, } return 0; } - + // Handle add with a constant RHS. if (Inst->getOpcode() == Instruction::Add && isa<ConstantInt>(Inst->getOperand(1))) { @@ -253,10 +263,10 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, Constant *RHS = cast<ConstantInt>(Inst->getOperand(1)); bool isNSW = cast<BinaryOperator>(Inst)->hasNoSignedWrap(); bool isNUW = cast<BinaryOperator>(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<BinaryOperator>(LHS)) if (BOp->getOpcode() == Instruction::Add) @@ -264,16 +274,16 @@ 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)) { + if (Value *Res = SimplifyAddInst(LHS, RHS, isNSW, isNUW, TD, DT)) { // If we simplified the operands, the LHS is no longer an input, but Res // is. RemoveInstInputs(LHS, InstInputs); @@ -283,7 +293,7 @@ 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) { @@ -294,10 +304,10 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, (!DT || DT->dominates(BO->getParent(), PredBB))) return BO; } - + return 0; } - + // Otherwise, we failed. return 0; } @@ -335,13 +345,13 @@ PHITranslateWithInsertion(BasicBlock *CurBB, BasicBlock *PredBB, const DominatorTree &DT, SmallVectorImpl<Instruction*> &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(); @@ -367,21 +377,23 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, // If we don't have an available version of this value, it must be an // instruction. Instruction *Inst = cast<Instruction>(InVal); - - // Handle bitcast of PHI translatable value. - if (BitCastInst *BC = dyn_cast<BitCastInst>(Inst)) { - Value *OpVal = InsertPHITranslatedSubExpr(BC->getOperand(0), + + // Handle cast of PHI translatable value. + if (CastInst *Cast = dyn_cast<CastInst>(Inst)) { + if (!Cast->isSafeToSpeculativelyExecute()) return 0; + Value *OpVal = InsertPHITranslatedSubExpr(Cast->getOperand(0), CurBB, PredBB, DT, NewInsts); if (OpVal == 0) return 0; - - // Otherwise insert a bitcast at the end of PredBB. - BitCastInst *New = new BitCastInst(OpVal, InVal->getType(), - InVal->getName()+".phi.trans.insert", - PredBB->getTerminator()); + + // Otherwise insert a cast at the end of PredBB. + CastInst *New = CastInst::Create(Cast->getOpcode(), + OpVal, InVal->getType(), + InVal->getName()+".phi.trans.insert", + PredBB->getTerminator()); NewInsts.push_back(New); return New; } - + // Handle getelementptr with at least one PHI operand. if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Inst)) { SmallVector<Value*, 8> GEPOps; @@ -392,8 +404,8 @@ 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()); @@ -401,12 +413,12 @@ 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<ConstantInt>(Inst->getOperand(1))) { @@ -414,7 +426,7 @@ 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()); @@ -424,6 +436,6 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, return Res; } #endif - + return 0; } |
