diff options
Diffstat (limited to 'lib/Transforms/Utils')
-rw-r--r-- | lib/Transforms/Utils/CloneTrace.cpp | 119 | ||||
-rw-r--r-- | lib/Transforms/Utils/InlineCost.cpp | 315 |
2 files changed, 0 insertions, 434 deletions
diff --git a/lib/Transforms/Utils/CloneTrace.cpp b/lib/Transforms/Utils/CloneTrace.cpp deleted file mode 100644 index 0711139..0000000 --- a/lib/Transforms/Utils/CloneTrace.cpp +++ /dev/null @@ -1,119 +0,0 @@ -//===- CloneTrace.cpp - Clone a trace -------------------------------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This file implements the CloneTrace interface, which is used when writing -// runtime optimizations. It takes a vector of basic blocks clones the basic -// blocks, removes internal phi nodes, adds it to the same function as the -// original (although there is no jump to it) and returns the new vector of -// basic blocks. -// -//===----------------------------------------------------------------------===// - -#include "llvm/Analysis/Trace.h" -#include "llvm/Transforms/Utils/Cloning.h" -#include "llvm/Instructions.h" -#include "llvm/Function.h" -#include "llvm/Transforms/Utils/ValueMapper.h" -using namespace llvm; - -//Clones the trace (a vector of basic blocks) -std::vector<BasicBlock *> -llvm::CloneTrace(const std::vector<BasicBlock*> &origTrace) { - std::vector<BasicBlock *> clonedTrace; - DenseMap<const Value*, Value*> ValueMap; - - //First, loop over all the Basic Blocks in the trace and copy - //them using CloneBasicBlock. Also fix the phi nodes during - //this loop. To fix the phi nodes, we delete incoming branches - //that are not in the trace. - for (std::vector<BasicBlock *>::const_iterator T = origTrace.begin(), - End = origTrace.end(); T != End; ++T) { - - //Clone Basic Block - BasicBlock *clonedBlock = - CloneBasicBlock(*T, ValueMap, ".tr", (*T)->getParent()); - - //Add it to our new trace - clonedTrace.push_back(clonedBlock); - - //Add this new mapping to our Value Map - ValueMap[*T] = clonedBlock; - - //Loop over the phi instructions and delete operands - //that are from blocks not in the trace - //only do this if we are NOT the first block - if (T != origTrace.begin()) { - for (BasicBlock::iterator I = clonedBlock->begin(); - isa<PHINode>(I); ++I) { - PHINode *PN = cast<PHINode>(I); - //get incoming value for the previous BB - Value *V = PN->getIncomingValueForBlock(*(T-1)); - assert(V && "No incoming value from a BasicBlock in our trace!"); - - //remap our phi node to point to incoming value - ValueMap[*&I] = V; - - //remove phi node - clonedBlock->getInstList().erase(PN); - } - } - } - - //Second loop to do the remapping - for (std::vector<BasicBlock *>::const_iterator BB = clonedTrace.begin(), - BE = clonedTrace.end(); BB != BE; ++BB) { - for (BasicBlock::iterator I = (*BB)->begin(); I != (*BB)->end(); ++I) { - //Loop over all the operands of the instruction - for (unsigned op=0, E = I->getNumOperands(); op != E; ++op) { - const Value *Op = I->getOperand(op); - - //Get it out of the value map - Value *V = ValueMap[Op]; - - //If not in the value map, then its outside our trace so ignore - if (V != 0) - I->setOperand(op,V); - } - } - } - - //return new vector of basic blocks - return clonedTrace; -} - -/// CloneTraceInto - Clone T into NewFunc. Original<->clone mapping is -/// saved in ValueMap. -/// -void llvm::CloneTraceInto(Function *NewFunc, Trace &T, - DenseMap<const Value*, Value*> &ValueMap, - const char *NameSuffix) { - assert(NameSuffix && "NameSuffix cannot be null!"); - - // Loop over all of the basic blocks in the trace, cloning them as - // appropriate. - // - for (Trace::const_iterator BI = T.begin(), BE = T.end(); BI != BE; ++BI) { - const BasicBlock *BB = *BI; - - // Create a new basic block and copy instructions into it! - BasicBlock *CBB = CloneBasicBlock(BB, ValueMap, NameSuffix, NewFunc); - ValueMap[BB] = CBB; // Add basic block mapping. - } - - // Loop over all of the instructions in the new function, fixing up operand - // references as we go. This uses ValueMap to do all the hard work. - // - for (Function::iterator BB = - cast<BasicBlock>(ValueMap[T.getEntryBasicBlock()]), - BE = NewFunc->end(); BB != BE; ++BB) - // Loop over all instructions, fixing each one as we find it... - for (BasicBlock::iterator II = BB->begin(); II != BB->end(); ++II) - RemapInstruction(II, ValueMap); -} - diff --git a/lib/Transforms/Utils/InlineCost.cpp b/lib/Transforms/Utils/InlineCost.cpp deleted file mode 100644 index 87aff01..0000000 --- a/lib/Transforms/Utils/InlineCost.cpp +++ /dev/null @@ -1,315 +0,0 @@ -//===- InlineCost.cpp - Cost analysis for inliner -------------------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This file implements inline cost analysis. -// -//===----------------------------------------------------------------------===// - - -#include "llvm/Transforms/Utils/InlineCost.h" -#include "llvm/Support/CallSite.h" -#include "llvm/CallingConv.h" -#include "llvm/IntrinsicInst.h" - -using namespace llvm; - -// CountCodeReductionForConstant - Figure out an approximation for how many -// instructions will be constant folded if the specified value is constant. -// -unsigned InlineCostAnalyzer::FunctionInfo:: - CountCodeReductionForConstant(Value *V) { - unsigned Reduction = 0; - for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E; ++UI) - if (isa<BranchInst>(*UI)) - Reduction += 40; // Eliminating a conditional branch is a big win - else if (SwitchInst *SI = dyn_cast<SwitchInst>(*UI)) - // Eliminating a switch is a big win, proportional to the number of edges - // deleted. - Reduction += (SI->getNumSuccessors()-1) * 40; - else if (CallInst *CI = dyn_cast<CallInst>(*UI)) { - // Turning an indirect call into a direct call is a BIG win - Reduction += CI->getCalledValue() == V ? 500 : 0; - } else if (InvokeInst *II = dyn_cast<InvokeInst>(*UI)) { - // Turning an indirect call into a direct call is a BIG win - Reduction += II->getCalledValue() == V ? 500 : 0; - } else { - // Figure out if this instruction will be removed due to simple constant - // propagation. - Instruction &Inst = cast<Instruction>(**UI); - bool AllOperandsConstant = true; - for (unsigned i = 0, e = Inst.getNumOperands(); i != e; ++i) - if (!isa<Constant>(Inst.getOperand(i)) && Inst.getOperand(i) != V) { - AllOperandsConstant = false; - break; - } - - if (AllOperandsConstant) { - // We will get to remove this instruction... - Reduction += 7; - - // And any other instructions that use it which become constants - // themselves. - Reduction += CountCodeReductionForConstant(&Inst); - } - } - - return Reduction; -} - -// CountCodeReductionForAlloca - Figure out an approximation of how much smaller -// the function will be if it is inlined into a context where an argument -// becomes an alloca. -// -unsigned InlineCostAnalyzer::FunctionInfo:: - CountCodeReductionForAlloca(Value *V) { - if (!isa<PointerType>(V->getType())) return 0; // Not a pointer - unsigned Reduction = 0; - for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E;++UI){ - Instruction *I = cast<Instruction>(*UI); - if (isa<LoadInst>(I) || isa<StoreInst>(I)) - Reduction += 10; - else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(I)) { - // If the GEP has variable indices, we won't be able to do much with it. - if (!GEP->hasAllConstantIndices()) - Reduction += CountCodeReductionForAlloca(GEP)+15; - } else { - // If there is some other strange instruction, we're not going to be able - // to do much if we inline this. - return 0; - } - } - - return Reduction; -} - -/// analyzeFunction - Fill in the current structure with information gleaned -/// from the specified function. -void InlineCostAnalyzer::FunctionInfo::analyzeFunction(Function *F) { - unsigned NumInsts = 0, NumBlocks = 0, NumVectorInsts = 0; - - // Look at the size of the callee. Each basic block counts as 20 units, and - // each instruction counts as 5. - for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) { - for (BasicBlock::const_iterator II = BB->begin(), E = BB->end(); - II != E; ++II) { - if (isa<PHINode>(II)) continue; // PHI nodes don't count. - - // Special handling for calls. - if (isa<CallInst>(II) || isa<InvokeInst>(II)) { - if (isa<DbgInfoIntrinsic>(II)) - continue; // Debug intrinsics don't count as size. - - CallSite CS = CallSite::get(const_cast<Instruction*>(&*II)); - - // If this function contains a call to setjmp or _setjmp, never inline - // it. This is a hack because we depend on the user marking their local - // variables as volatile if they are live across a setjmp call, and they - // probably won't do this in callers. - if (Function *F = CS.getCalledFunction()) - if (F->isDeclaration() && - (F->isName("setjmp") || F->isName("_setjmp"))) { - NeverInline = true; - return; - } - - // Calls often compile into many machine instructions. Bump up their - // cost to reflect this. - if (!isa<IntrinsicInst>(II)) - NumInsts += 5; - } - - if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) { - if (!AI->isStaticAlloca()) - this->usesDynamicAlloca = true; - } - - if (isa<ExtractElementInst>(II) || isa<VectorType>(II->getType())) - ++NumVectorInsts; - - // Noop casts, including ptr <-> int, don't count. - if (const CastInst *CI = dyn_cast<CastInst>(II)) { - if (CI->isLosslessCast() || isa<IntToPtrInst>(CI) || - isa<PtrToIntInst>(CI)) - continue; - } else if (const GetElementPtrInst *GEPI = - dyn_cast<GetElementPtrInst>(II)) { - // If a GEP has all constant indices, it will probably be folded with - // a load/store. - if (GEPI->hasAllConstantIndices()) - continue; - } - - ++NumInsts; - } - - ++NumBlocks; - } - - this->NumBlocks = NumBlocks; - this->NumInsts = NumInsts; - this->NumVectorInsts = NumVectorInsts; - - // Check out all of the arguments to the function, figuring out how much - // code can be eliminated if one of the arguments is a constant. - for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I) - ArgumentWeights.push_back(ArgInfo(CountCodeReductionForConstant(I), - CountCodeReductionForAlloca(I))); -} - - - -// getInlineCost - The heuristic used to determine if we should inline the -// function call or not. -// -InlineCost InlineCostAnalyzer::getInlineCost(CallSite CS, - SmallPtrSet<const Function *, 16> &NeverInline) { - Instruction *TheCall = CS.getInstruction(); - Function *Callee = CS.getCalledFunction(); - Function *Caller = TheCall->getParent()->getParent(); - - // Don't inline functions which can be redefined at link-time to mean - // something else. - if (Callee->mayBeOverridden() || - // Don't inline functions marked noinline. - Callee->hasFnAttr(Attribute::NoInline) || NeverInline.count(Callee)) - return llvm::InlineCost::getNever(); - - // InlineCost - This value measures how good of an inline candidate this call - // site is to inline. A lower inline cost make is more likely for the call to - // be inlined. This value may go negative. - // - int InlineCost = 0; - - // If there is only one call of the function, and it has internal linkage, - // make it almost guaranteed to be inlined. - // - if ((Callee->hasLocalLinkage() || Callee->hasAvailableExternallyLinkage()) && - Callee->hasOneUse()) - InlineCost -= 15000; - - // If this function uses the coldcc calling convention, prefer not to inline - // it. - if (Callee->getCallingConv() == CallingConv::Cold) - InlineCost += 2000; - - // If the instruction after the call, or if the normal destination of the - // invoke is an unreachable instruction, the function is noreturn. As such, - // there is little point in inlining this. - if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) { - if (isa<UnreachableInst>(II->getNormalDest()->begin())) - InlineCost += 10000; - } else if (isa<UnreachableInst>(++BasicBlock::iterator(TheCall))) - InlineCost += 10000; - - // Get information about the callee... - FunctionInfo &CalleeFI = CachedFunctionInfo[Callee]; - - // If we haven't calculated this information yet, do so now. - if (CalleeFI.NumBlocks == 0) - CalleeFI.analyzeFunction(Callee); - - // If we should never inline this, return a huge cost. - if (CalleeFI.NeverInline) - return InlineCost::getNever(); - - // FIXME: It would be nice to kill off CalleeFI.NeverInline. Then we - // could move this up and avoid computing the FunctionInfo for - // things we are going to just return always inline for. This - // requires handling setjmp somewhere else, however. - if (!Callee->isDeclaration() && Callee->hasFnAttr(Attribute::AlwaysInline)) - return InlineCost::getAlways(); - - if (CalleeFI.usesDynamicAlloca) { - // Get infomation about the caller... - FunctionInfo &CallerFI = CachedFunctionInfo[Caller]; - - // If we haven't calculated this information yet, do so now. - if (CallerFI.NumBlocks == 0) - CallerFI.analyzeFunction(Caller); - - // Don't inline a callee with dynamic alloca into a caller without them. - // Functions containing dynamic alloca's are inefficient in various ways; - // don't create more inefficiency. - if (!CallerFI.usesDynamicAlloca) - return InlineCost::getNever(); - } - - // Add to the inline quality for properties that make the call valuable to - // inline. This includes factors that indicate that the result of inlining - // the function will be optimizable. Currently this just looks at arguments - // passed into the function. - // - unsigned ArgNo = 0; - for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); - I != E; ++I, ++ArgNo) { - // Each argument passed in has a cost at both the caller and the callee - // sides. This favors functions that take many arguments over functions - // that take few arguments. - InlineCost -= 20; - - // If this is a function being passed in, it is very likely that we will be - // able to turn an indirect function call into a direct function call. - if (isa<Function>(I)) - InlineCost -= 100; - - // If an alloca is passed in, inlining this function is likely to allow - // significant future optimization possibilities (like scalar promotion, and - // scalarization), so encourage the inlining of the function. - // - else if (isa<AllocaInst>(I)) { - if (ArgNo < CalleeFI.ArgumentWeights.size()) - InlineCost -= CalleeFI.ArgumentWeights[ArgNo].AllocaWeight; - - // If this is a constant being passed into the function, use the argument - // weights calculated for the callee to determine how much will be folded - // away with this information. - } else if (isa<Constant>(I)) { - if (ArgNo < CalleeFI.ArgumentWeights.size()) - InlineCost -= CalleeFI.ArgumentWeights[ArgNo].ConstantWeight; - } - } - - // Now that we have considered all of the factors that make the call site more - // likely to be inlined, look at factors that make us not want to inline it. - - // Don't inline into something too big, which would make it bigger. - // - InlineCost += Caller->size()/15; - - // Look at the size of the callee. Each instruction counts as 5. - InlineCost += CalleeFI.NumInsts*5; - - return llvm::InlineCost::get(InlineCost); -} - -// getInlineFudgeFactor - Return a > 1.0 factor if the inliner should use a -// higher threshold to determine if the function call should be inlined. -float InlineCostAnalyzer::getInlineFudgeFactor(CallSite CS) { - Function *Callee = CS.getCalledFunction(); - - // Get information about the callee... - FunctionInfo &CalleeFI = CachedFunctionInfo[Callee]; - - // If we haven't calculated this information yet, do so now. - if (CalleeFI.NumBlocks == 0) - CalleeFI.analyzeFunction(Callee); - - float Factor = 1.0f; - // Single BB functions are often written to be inlined. - if (CalleeFI.NumBlocks == 1) - Factor += 0.5f; - - // Be more aggressive if the function contains a good chunk (if it mades up - // at least 10% of the instructions) of vector instructions. - if (CalleeFI.NumVectorInsts > CalleeFI.NumInsts/2) - Factor += 2.0f; - else if (CalleeFI.NumVectorInsts > CalleeFI.NumInsts/10) - Factor += 1.5f; - return Factor; -} |