llvm-6502/lib/Transforms/IPO/InlineSimple.cpp
Daniel Dunbar c5e1ec47c7 Add InlineCost class for represent the estimated cost of inlining a
function.
 - This explicitly models the costs for functions which should
   "always" or "never" be inlined. This fixes bugs where such costs
   were not previously respected.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58450 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-30 19:26:59 +00:00

104 lines
3.0 KiB
C++

//===- InlineSimple.cpp - Code to perform simple function inlining --------===//
//
// The LLVM Compiler Infrastructure
//
// 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.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "inline"
#include "llvm/CallingConv.h"
#include "llvm/Instructions.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/Module.h"
#include "llvm/Type.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/IPO/InlinerPass.h"
#include "llvm/Transforms/Utils/InlineCost.h"
#include "llvm/ADT/SmallPtrSet.h"
using namespace llvm;
namespace {
class VISIBILITY_HIDDEN SimpleInliner : public Inliner {
// Functions that are never inlined
SmallPtrSet<const Function*, 16> NeverInline;
InlineCostAnalyzer CA;
public:
SimpleInliner() : Inliner(&ID) {}
SimpleInliner(int Threshold) : Inliner(&ID, Threshold) {}
static char ID; // Pass identification, replacement for typeid
InlineCost getInlineCost(CallSite CS) {
return CA.getInlineCost(CS, NeverInline);
}
float getInlineFudgeFactor(CallSite CS) {
return CA.getInlineFudgeFactor(CS);
}
virtual bool doInitialization(CallGraph &CG);
};
}
char SimpleInliner::ID = 0;
static RegisterPass<SimpleInliner>
X("inline", "Function Integration/Inlining");
Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
Pass *llvm::createFunctionInliningPass(int Threshold) {
return new SimpleInliner(Threshold);
}
// doInitialization - Initializes the vector of functions that have been
// annotated with the noinline attribute.
bool SimpleInliner::doInitialization(CallGraph &CG) {
Module &M = CG.getModule();
for (Module::iterator I = M.begin(), E = M.end();
I != E; ++I)
if (!I->isDeclaration() && I->hasFnAttr(Attribute::NoInline))
NeverInline.insert(I);
// Get llvm.noinline
GlobalVariable *GV = M.getNamedGlobal("llvm.noinline");
if (GV == 0)
return false;
// Don't crash on invalid code
if (!GV->hasInitializer())
return false;
const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
if (InitList == 0)
return false;
// Iterate over each element and add to the NeverInline set
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
// Get Source
const Constant *Elt = InitList->getOperand(i);
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt))
if (CE->getOpcode() == Instruction::BitCast)
Elt = CE->getOperand(0);
// Insert into set of functions to never inline
if (const Function *F = dyn_cast<Function>(Elt))
NeverInline.insert(F);
}
return false;
}