//===- InlineSimple.cpp - Code to perform simple function inlining --------===//
-//
+//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
//===----------------------------------------------------------------------===//
//
// This file implements bottom-up inlining of functions into callees.
//
//===----------------------------------------------------------------------===//
-#include "Inliner.h"
-#include "llvm/Instructions.h"
-#include "llvm/Function.h"
-#include "llvm/Type.h"
-#include "llvm/Support/CallSite.h"
+#include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/Analysis/InlineCost.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/CallingConv.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Type.h"
#include "llvm/Transforms/IPO.h"
+#include "llvm/Transforms/IPO/InlinerPass.h"
+
using namespace llvm;
+#define DEBUG_TYPE "inline"
+
namespace {
- struct ArgInfo {
- unsigned ConstantWeight;
- unsigned AllocaWeight;
-
- ArgInfo(unsigned CWeight, unsigned AWeight)
- : ConstantWeight(CWeight), AllocaWeight(AWeight) {}
- };
-
- // FunctionInfo - For each function, calculate the size of it in blocks and
- // instructions.
- struct FunctionInfo {
- // NumInsts, NumBlocks - Keep track of how large each function is, which is
- // used to estimate the code size cost of inlining it.
- unsigned NumInsts, NumBlocks;
-
- // ArgumentWeights - Each formal argument of the function is inspected to
- // see if it is used in any contexts where making it a constant or alloca
- // would reduce the code size. If so, we add some value to the argument
- // entry here.
- std::vector<ArgInfo> ArgumentWeights;
-
- FunctionInfo() : NumInsts(0), NumBlocks(0) {}
- };
-
- class SimpleInliner : public Inliner {
- std::map<const Function*, FunctionInfo> CachedFunctionInfo;
- public:
- int getInlineCost(CallSite CS);
- };
- RegisterOpt<SimpleInliner> X("inline", "Function Integration/Inlining");
-}
-Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
+/// \brief Actual inliner pass implementation.
+///
+/// The common implementation of the inlining logic is shared between this
+/// inliner pass and the always inliner pass. The two passes use different cost
+/// analyses to determine when to inline.
+class SimpleInliner : public Inliner {
-// CountCodeReductionForConstant - Figure out an approximation for how many
-// instructions will be constant folded if the specified value is constant.
-//
-static unsigned 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;
-}
+public:
+ SimpleInliner() : Inliner(ID) {
+ initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
+ }
-// 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.
-//
-static unsigned 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.
- for (Instruction::op_iterator I = GEP->op_begin()+1, E = GEP->op_end();
- I != E; ++I)
- if (!isa<Constant>(*I)) return 0;
- 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;
- }
+ SimpleInliner(int Threshold)
+ : Inliner(ID, Threshold, /*InsertLifetime*/ true) {
+ initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
}
- return Reduction;
-}
+ static char ID; // Pass identification, replacement for typeid
-// getInlineCost - The heuristic used to determine if we should inline the
-// function call or not.
-//
-int SimpleInliner::getInlineCost(CallSite CS) {
- Instruction *TheCall = CS.getInstruction();
- Function *Callee = CS.getCalledFunction();
- const Function *Caller = TheCall->getParent()->getParent();
-
- // Don't inline a directly recursive call.
- if (Caller == Callee) return 2000000000;
-
- // 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->hasInternalLinkage() && Callee->hasOneUse())
- InlineCost -= 30000;
-
- // Get information about the callee...
- FunctionInfo &CalleeFI = CachedFunctionInfo[Callee];
-
- // If we haven't calculated this information yet...
- if (CalleeFI.NumBlocks == 0) {
- unsigned NumInsts = 0, NumBlocks = 0;
-
- // Look at the size of the callee. Each basic block counts as 20 units, and
- // each instruction counts as 10.
- for (Function::const_iterator BB = Callee->begin(), E = Callee->end();
- BB != E; ++BB) {
- NumInsts += BB->size();
- NumBlocks++;
- }
-
- CalleeFI.NumBlocks = NumBlocks;
- CalleeFI.NumInsts = NumInsts;
-
- // 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.
- std::vector<ArgInfo> &ArgWeights = CalleeFI.ArgumentWeights;
-
- for (Function::aiterator I = Callee->abegin(), E = Callee->aend();
- I != E; ++I)
- ArgWeights.push_back(ArgInfo(CountCodeReductionForConstant(I),
- CountCodeReductionForAlloca(I)));
+ InlineCost getInlineCost(CallSite CS) override {
+ Function *Callee = CS.getCalledFunction();
+ TargetTransformInfo &TTI = TTIWP->getTTI(*Callee);
+ return llvm::getInlineCost(CS, getInlineThreshold(CS), TTI, ACT);
}
+ bool runOnSCC(CallGraphSCC &SCC) override;
+ void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+private:
+ TargetTransformInfoWrapperPass *TTIWP;
+};
+
+static int computeThresholdFromOptLevels(unsigned OptLevel,
+ unsigned SizeOptLevel) {
+ if (OptLevel > 2)
+ return 275;
+ if (SizeOptLevel == 1) // -Os
+ return 75;
+ if (SizeOptLevel == 2) // -Oz
+ return 25;
+ return 225;
+}
- // 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 (AllocaInst *AI = dyn_cast<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;
- }
- }
+} // end anonymous namespace
- // 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.
+char SimpleInliner::ID = 0;
+INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
+ "Function Integration/Inlining", false, false)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
+INITIALIZE_PASS_END(SimpleInliner, "inline",
+ "Function Integration/Inlining", false, false)
- // Don't inline into something too big, which would make it bigger. Here, we
- // count each basic block as a single unit.
- //
- InlineCost += Caller->size()/20;
+Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
+Pass *llvm::createFunctionInliningPass(int Threshold) {
+ return new SimpleInliner(Threshold);
+}
+
+Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
+ unsigned SizeOptLevel) {
+ return new SimpleInliner(
+ computeThresholdFromOptLevels(OptLevel, SizeOptLevel));
+}
- // Look at the size of the callee. Each basic block counts as 20 units, and
- // each instruction counts as 5.
- InlineCost += CalleeFI.NumInsts*5 + CalleeFI.NumBlocks*20;
- return InlineCost;
+bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
+ TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
+ return Inliner::runOnSCC(SCC);
}
+void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<TargetTransformInfoWrapperPass>();
+ Inliner::getAnalysisUsage(AU);
+}
projects / oota-llvm.git / blobdiff