From 6fcca1cc874c2b374b05399be92c5c1ea2086cc0 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Mon, 7 Dec 2009 19:04:49 +0000 Subject: [PATCH] add support for phi translation and incorpation of new expression. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90782 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/PHITransAddr.cpp | 281 ++++++++++++++++++---------------- 1 file changed, 152 insertions(+), 129 deletions(-) diff --git a/lib/Analysis/PHITransAddr.cpp b/lib/Analysis/PHITransAddr.cpp index bdaaac1eaa1..40800b4e581 100644 --- a/lib/Analysis/PHITransAddr.cpp +++ b/lib/Analysis/PHITransAddr.cpp @@ -16,6 +16,22 @@ #include "llvm/Analysis/InstructionSimplify.h" using namespace llvm; +static bool CanPHITrans(Instruction *Inst) { + if (isa(Inst) || + isa(Inst) || + isa(Inst)) + return true; + + if (Inst->getOpcode() == Instruction::And && + 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); + return false; +} + /// IsPotentiallyPHITranslatable - If this needs PHI translation, return true /// if we have some hope of doing it. This should be used as a filter to /// avoid calling PHITranslateValue in hopeless situations. @@ -23,18 +39,7 @@ bool PHITransAddr::IsPotentiallyPHITranslatable() const { // If the input value is not an instruction, or if it is not defined in CurBB, // then we don't need to phi translate it. Instruction *Inst = dyn_cast(Addr); - if (isa(Inst) || - isa(Inst) || - isa(Inst) || - (Inst->getOpcode() == Instruction::And && - 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); - - return false; + return Inst == 0 || CanPHITrans(Inst); } @@ -44,129 +49,147 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, 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); - - // If 'Inst' is not defined in this block, it is either an input, or an - // intermediate result. - if (Inst->getParent() != CurBB) { - // If it is an input, then it remains an input. + // If 'Inst' is defined in this block, it must be an input that needs to be + // phi translated or an intermediate expression that needs to be incorporated + // into the expression. + if (Inst->getParent() == CurBB) { + assert(std::count(InstInputs.begin(), InstInputs.end(), Inst) && + "Not an input?"); + + // If this is a PHI, go ahead and translate it. + if (PHINode *PN = dyn_cast(Inst)) + return 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; + + // Okay, we can incorporate it, this instruction is no longer an input. + InstInputs.erase(std::find(InstInputs.begin(), InstInputs.end(), Inst)); + + // 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) + if (Instruction *Op = dyn_cast(Inst->getOperand(i))) + InstInputs.push_back(Op); + + } else { + // Determine whether 'Inst' is an input to our PHI translatable expression. + bool isInput = std::count(InstInputs.begin(), InstInputs.end(), Inst); + + // If it is an input defined in a different block, then it remains an input. if (isInput) return Inst; - - // Otherwise, it must be an intermediate result. See if its operands need - // to be phi translated, and if so, reconstruct it. - - if (BitCastInst *BC = dyn_cast(Inst)) { - Value *PHIIn = PHITranslateSubExpr(BC->getOperand(0), CurBB, PredBB); - if (PHIIn == 0) return 0; - if (PHIIn == BC->getOperand(0)) - return BC; - - // Find an available version of this cast. - - // Constants are trivial to find. - if (Constant *C = dyn_cast(PHIIn)) - return ConstantExpr::getBitCast(C, BC->getType()); - - // Otherwise we have to see if a bitcasted 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(*UI)) - if (BCI->getType() == BC->getType()) - return BCI; - } - return 0; - } - - // Handle getelementptr with at least one PHI translatable operand. - if (GetElementPtrInst *GEP = dyn_cast(Inst)) { - SmallVector GEPOps; - BasicBlock *CurBB = GEP->getParent(); - bool AnyChanged = false; - for (unsigned i = 0, e = GEP->getNumOperands(); i != e; ++i) { - Value *GEPOp = PHITranslateSubExpr(GEP->getOperand(i), CurBB, PredBB); - 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)) - return 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(); - UI != E; ++UI) { - if (GetElementPtrInst *GEPI = dyn_cast(*UI)) - if (GEPI->getType() == GEP->getType() && - GEPI->getNumOperands() == GEPOps.size() && - GEPI->getParent()->getParent() == CurBB->getParent()) { - bool Mismatch = false; - for (unsigned i = 0, e = GEPOps.size(); i != e; ++i) - if (GEPI->getOperand(i) != GEPOps[i]) { - Mismatch = true; - break; - } - if (!Mismatch) - return GEPI; - } - } - return 0; - } - - // Handle add with a constant RHS. - if (Inst->getOpcode() == Instruction::Add && - isa(Inst->getOperand(1))) { - // PHI translate the LHS. - Constant *RHS = cast(Inst->getOperand(1)); - bool isNSW = cast(Inst)->hasNoSignedWrap(); - bool isNUW = cast(Inst)->hasNoUnsignedWrap(); - - Value *LHS = PHITranslateSubExpr(Inst->getOperand(0), CurBB, PredBB); - 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) - if (ConstantInt *CI = dyn_cast(BOp->getOperand(1))) { - LHS = BOp->getOperand(0); - RHS = ConstantExpr::getAdd(RHS, CI); - isNSW = isNUW = false; - } - - // See if the add simplifies away. - if (Value *Res = SimplifyAddInst(LHS, RHS, isNSW, isNUW, TD)) - return Res; - - // Otherwise, see if we have this add available somewhere. - for (Value::use_iterator UI = LHS->use_begin(), E = LHS->use_end(); - UI != E; ++UI) { - if (BinaryOperator *BO = dyn_cast(*UI)) - if (BO->getOperand(0) == LHS && BO->getOperand(1) == RHS && - BO->getParent()->getParent() == CurBB->getParent()) - return BO; - } - - return 0; - } - - // Otherwise, we failed. - return 0; } - // Otherwise, it is defined in this block. It must be an input and must be - // phi translated. - assert(isInput && "Instruction defined in block must be an input"); + // 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(Inst)) { + Value *PHIIn = PHITranslateSubExpr(BC->getOperand(0), CurBB, PredBB); + if (PHIIn == 0) return 0; + if (PHIIn == BC->getOperand(0)) + return BC; + + // Find an available version of this cast. + + // Constants are trivial to find. + if (Constant *C = dyn_cast(PHIIn)) + return ConstantExpr::getBitCast(C, BC->getType()); + + // Otherwise we have to see if a bitcasted 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(*UI)) + if (BCI->getType() == BC->getType()) + return BCI; + } + return 0; + } - abort(); // unimplemented so far. + // Handle getelementptr with at least one PHI translatable operand. + if (GetElementPtrInst *GEP = dyn_cast(Inst)) { + SmallVector GEPOps; + BasicBlock *CurBB = GEP->getParent(); + bool AnyChanged = false; + for (unsigned i = 0, e = GEP->getNumOperands(); i != e; ++i) { + Value *GEPOp = PHITranslateSubExpr(GEP->getOperand(i), CurBB, PredBB); + 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)) + return 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(); + UI != E; ++UI) { + if (GetElementPtrInst *GEPI = dyn_cast(*UI)) + if (GEPI->getType() == GEP->getType() && + GEPI->getNumOperands() == GEPOps.size() && + GEPI->getParent()->getParent() == CurBB->getParent()) { + bool Mismatch = false; + for (unsigned i = 0, e = GEPOps.size(); i != e; ++i) + if (GEPI->getOperand(i) != GEPOps[i]) { + Mismatch = true; + break; + } + if (!Mismatch) + return GEPI; + } + } + return 0; + } + + // Handle add with a constant RHS. + if (Inst->getOpcode() == Instruction::Add && + isa(Inst->getOperand(1))) { + // PHI translate the LHS. + Constant *RHS = cast(Inst->getOperand(1)); + bool isNSW = cast(Inst)->hasNoSignedWrap(); + bool isNUW = cast(Inst)->hasNoUnsignedWrap(); + + Value *LHS = PHITranslateSubExpr(Inst->getOperand(0), CurBB, PredBB); + 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) + if (ConstantInt *CI = dyn_cast(BOp->getOperand(1))) { + LHS = BOp->getOperand(0); + RHS = ConstantExpr::getAdd(RHS, CI); + isNSW = isNUW = false; + } + + // See if the add simplifies away. + if (Value *Res = SimplifyAddInst(LHS, RHS, isNSW, isNUW, TD)) + return Res; + + // Otherwise, see if we have this add available somewhere. + for (Value::use_iterator UI = LHS->use_begin(), E = LHS->use_end(); + UI != E; ++UI) { + if (BinaryOperator *BO = dyn_cast(*UI)) + if (BO->getOperand(0) == LHS && BO->getOperand(1) == RHS && + BO->getParent()->getParent() == CurBB->getParent()) + return BO; + } + + return 0; + } + + // Otherwise, we failed. + return 0; }