[llvm-commits] CVS: llvm/lib/Transforms/IPO/Inliner.cpp Inliner.h InlineSimple.cpp
Chris Lattner
lattner at cs.uiuc.edu
Sun Aug 31 14:11:01 PDT 2003
Changes in directory llvm/lib/Transforms/IPO:
Inliner.cpp added (r1.1)
Inliner.h added (r1.1)
InlineSimple.cpp updated: 1.49 -> 1.50
---
Log message:
Heavily refactor code:
* Separate the policy decisions into a derived class [InlineSimple]
* Move the inlining mechanics into a base class [Inliner]
* Change the inliner to be an SCCPass, making it more structured and
eventually pipelinable with other SCC passes
---
Diffs of the changes:
Index: llvm/lib/Transforms/IPO/Inliner.cpp
diff -c /dev/null llvm/lib/Transforms/IPO/Inliner.cpp:1.1
*** /dev/null Sun Aug 31 14:10:40 2003
--- llvm/lib/Transforms/IPO/Inliner.cpp Sun Aug 31 14:10:30 2003
***************
*** 0 ****
--- 1,119 ----
+ //===- InlineCommon.cpp - Code common to all inliners ---------------------===//
+ //
+ // This file implements the code shared between the LLVM inliners. This
+ // implements all of the boring mechanics of the bottom-up inlining.
+ //
+ //===----------------------------------------------------------------------===//
+
+ #include "Inliner.h"
+ #include "llvm/Module.h"
+ #include "llvm/iOther.h"
+ #include "llvm/iTerminators.h"
+ #include "llvm/Analysis/CallGraph.h"
+ #include "llvm/Support/CallSite.h"
+ #include "llvm/Transforms/Utils/Cloning.h"
+ #include "Support/CommandLine.h"
+ #include "Support/Debug.h"
+ #include "Support/Statistic.h"
+
+ namespace {
+ Statistic<> NumInlined("inline", "Number of functions inlined");
+ Statistic<> NumDeleted("inline", "Number of functions deleted because all callers found");
+ cl::opt<unsigned> // FIXME: 200 is VERY conservative
+ InlineLimit("inline-threshold", cl::Hidden, cl::init(200),
+ cl::desc("Control the amount of inlining to perform (default = 200)"));
+ }
+
+ Inliner::Inliner() : InlineThreshold(InlineLimit) {}
+
+ int Inliner::getRecursiveInlineCost(CallSite CS) {
+ return getInlineCost(CS);
+ }
+
+ bool Inliner::runOnSCC(const std::vector<CallGraphNode*> &SCC) {
+ CallGraph &CG = getAnalysis<CallGraph>();
+
+ std::set<Function*> SCCFunctions;
+ DEBUG(std::cerr << "Inliner visiting SCC:");
+ for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
+ SCCFunctions.insert(SCC[i]->getFunction());
+ DEBUG(std::cerr << " " << (SCC[i]->getFunction() ?
+ SCC[i]->getFunction()->getName() : "INDIRECTNODE"));
+ }
+ DEBUG(std::cerr << "\n");
+
+ bool Changed = false;
+ for (std::set<Function*>::iterator SCCI = SCCFunctions.begin(),
+ E = SCCFunctions.end(); SCCI != E; ++SCCI) {
+ Function *F = *SCCI;
+ if (F == 0 || F->isExternal()) continue;
+ DEBUG(std::cerr << " Inspecting function: " << F->getName() << "\n");
+
+ for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
+ for (BasicBlock::iterator I = BB->begin(); I != BB->end(); ) {
+ bool ShouldInc = true;
+ // Found a call or invoke instruction?
+ if (isa<CallInst>(I) || isa<InvokeInst>(I)) {
+ CallSite CS = CallSite::get(I);
+ if (Function *Callee = CS.getCalledFunction())
+ if (!Callee->isExternal()) {
+ // Determine whether this is a function IN the SCC...
+ bool inSCC = SCCFunctions.count(Callee);
+
+ // If the policy determines that we should inline this function,
+ // try to do so...
+ int InlineCost = inSCC ? getRecursiveInlineCost(CS) :
+ getInlineCost(CS);
+ if (InlineCost < (int)InlineThreshold) {
+ DEBUG(std::cerr << " Inlining: cost=" << InlineCost
+ << ", Call: " << *CS.getInstruction());
+
+ // Save an iterator to the instruction before the call if it
+ // exists, otherwise get an iterator at the end of the
+ // block... because the call will be destroyed.
+ //
+ BasicBlock::iterator SI;
+ if (I != BB->begin()) {
+ SI = I; --SI; // Instruction before the call...
+ } else {
+ SI = BB->end();
+ }
+
+ if (performInlining(CS, SCCFunctions)) {
+ // Move to instruction before the call...
+ I = (SI == BB->end()) ? BB->begin() : SI;
+ ShouldInc = false; // Don't increment iterator until next time
+ Changed = true;
+ }
+ }
+ }
+ }
+ if (ShouldInc) ++I;
+ }
+ }
+ return Changed;
+ }
+
+ bool Inliner::performInlining(CallSite CS, std::set<Function*> &SCC) {
+ Function *Callee = CS.getCalledFunction();
+ Function *Caller = CS.getInstruction()->getParent()->getParent();
+
+ // Attempt to inline the function...
+ if (!InlineFunction(CS)) return false;
+ ++NumInlined;
+
+ // If we inlined the last possible call site to the function,
+ // delete the function body now.
+ if (Callee->use_empty() && Callee != Caller &&
+ (Callee->hasInternalLinkage() || Callee->hasLinkOnceLinkage())) {
+ DEBUG(std::cerr << " -> Deleting dead function: "
+ << Callee->getName() << "\n");
+ std::set<Function*>::iterator I = SCC.find(Callee);
+ if (I != SCC.end()) // Remove function from this SCC...
+ SCC.erase(I);
+
+ Callee->getParent()->getFunctionList().erase(Callee);
+ ++NumDeleted;
+ }
+ return true;
+ }
Index: llvm/lib/Transforms/IPO/Inliner.h
diff -c /dev/null llvm/lib/Transforms/IPO/Inliner.h:1.1
*** /dev/null Sun Aug 31 14:10:40 2003
--- llvm/lib/Transforms/IPO/Inliner.h Sun Aug 31 14:10:30 2003
***************
*** 0 ****
--- 1,52 ----
+ //===- InlineCommon.h - Code common to all inliners -------------*- C++ -*-===//
+ //
+ // This file defines a simple policy-based bottom-up inliner. This file
+ // implements all of the boring mechanics of the bottom-up inlining, while the
+ // subclass determines WHAT to inline, which is the much more interesting
+ // component.
+ //
+ //===----------------------------------------------------------------------===//
+
+ #ifndef INLINER_H
+ #define INLINER_H
+
+ #define DEBUG_TYPE "inline"
+ #include "llvm/CallGraphSCCPass.h"
+ #include <set>
+ class CallSite;
+
+ /// Inliner - This class contains all of the helper code which is used to
+ /// perform the inlining operations that does not depend on the policy.
+ ///
+ struct Inliner : public CallGraphSCCPass {
+ Inliner();
+
+ // Main run interface method, this implements the interface required by the
+ // Pass class.
+ virtual bool runOnSCC(const std::vector<CallGraphNode *> &SCC);
+
+ /// This method returns the value specified by the -inline-threshold value,
+ /// specified on the command line. This is typically not directly needed.
+ ///
+ unsigned getInlineThreshold() const { return InlineThreshold; }
+
+ /// getInlineCost - This method must be implemented by the subclass to
+ /// determine the cost of inlining the specified call site. If the cost
+ /// returned is greater than the current inline threshold, the call site is
+ /// not inlined.
+ ///
+ virtual int getInlineCost(CallSite CS) = 0;
+
+ /// getRecursiveInlineCost - This method can be implemented by subclasses if
+ /// it wants to treat calls to functions within the current SCC specially. If
+ /// this method is not overloaded, it just chains to getInlineCost().
+ ///
+ virtual int getRecursiveInlineCost(CallSite CS);
+
+ private:
+ unsigned InlineThreshold;
+ bool performInlining(CallSite CS, std::set<Function*> &SCC);
+ };
+
+
+ #endif
Index: llvm/lib/Transforms/IPO/InlineSimple.cpp
diff -u llvm/lib/Transforms/IPO/InlineSimple.cpp:1.49 llvm/lib/Transforms/IPO/InlineSimple.cpp:1.50
--- llvm/lib/Transforms/IPO/InlineSimple.cpp:1.49 Sun Aug 24 01:59:28 2003
+++ llvm/lib/Transforms/IPO/InlineSimple.cpp Sun Aug 31 14:10:30 2003
@@ -1,77 +1,47 @@
-//===- FunctionInlining.cpp - Code to perform function inlining -----------===//
+//===- InlineSimple.cpp - Code to perform simple function inlining --------===//
//
// This file implements bottom-up inlining of functions into callees.
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "inline"
-#include "llvm/Transforms/IPO.h"
-#include "llvm/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/iOther.h"
+#include "Inliner.h"
+#include "llvm/Function.h"
#include "llvm/iMemory.h"
-#include "llvm/iTerminators.h"
#include "llvm/Support/CallSite.h"
-#include "llvm/Transforms/Utils/Cloning.h"
-#include "Support/CommandLine.h"
-#include "Support/Debug.h"
-#include "Support/Statistic.h"
-#include <set>
+#include "llvm/Transforms/IPO.h"
namespace {
- Statistic<> NumInlined("inline", "Number of functions inlined");
- Statistic<> NumDeleted("inline", "Number of functions deleted because all callers found");
- cl::opt<unsigned> // FIXME: 200 is VERY conservative
- InlineLimit("inline-threshold", cl::Hidden, cl::init(200),
- cl::desc("Control the amount of inlining to perform (default = 200)"));
-
- struct FunctionInlining : public Pass {
- virtual bool run(Module &M) {
- bool Changed = false;
- for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
- Changed |= doInlining(I);
- ProcessedFunctions.clear();
- return Changed;
- }
-
- private:
- std::set<Function*> ProcessedFunctions; // Prevent infinite recursion
- bool doInlining(Function *F);
+ struct SimpleInliner : public Inliner {
+ int getInlineCost(CallSite CS);
};
- RegisterOpt<FunctionInlining> X("inline", "Function Integration/Inlining");
+ RegisterOpt<SimpleInliner> X("inline", "Function Integration/Inlining");
}
-Pass *createFunctionInliningPass() { return new FunctionInlining(); }
+Pass *createFunctionInliningPass() { return new SimpleInliner(); }
-// ShouldInlineFunction - The heuristic used to determine if we should inline
-// the function call or not.
+// getInlineCost - The heuristic used to determine if we should inline the
+// function call or not.
//
-static inline bool ShouldInlineFunction(CallSite CS) {
+int SimpleInliner::getInlineCost(CallSite CS) {
Instruction *TheCall = CS.getInstruction();
- assert(TheCall->getParent() && TheCall->getParent()->getParent() &&
- "Call not embedded into a function!");
-
const Function *Callee = CS.getCalledFunction();
- if (Callee == 0 || Callee->isExternal())
- return false; // Cannot inline an indirect call... or external function.
-
- // Don't inline a recursive call.
const Function *Caller = TheCall->getParent()->getParent();
- if (Caller == Callee) return false;
- // InlineQuality - This value measures how good of an inline candidate this
- // call site is to inline. The initial value determines how aggressive the
- // inliner is. If this value is negative after the final computation,
- // inlining is not performed.
+ // 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 InlineQuality = InlineLimit;
+ 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->use_size() == 1 && Callee->hasInternalLinkage())
- InlineQuality += 30000;
+ InlineCost -= 30000;
// Add to the inline quality for properties that make the call valueable to
// inline. This includes factors that indicate that the result of inlining
@@ -83,12 +53,12 @@
// 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.
- InlineQuality += 20;
+ 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))
- InlineQuality += 100;
+ InlineCost -= 100;
// If a constant, global variable or alloca is passed in, inlining this
// function is likely to allow significant future optimization possibilities
@@ -96,7 +66,7 @@
// the inlining of the function.
//
else if (isa<Constant>(I) || isa<GlobalVariable>(I) || isa<AllocaInst>(I))
- InlineQuality += 60;
+ InlineCost -= 60;
}
// Now that we have considered all of the factors that make the call site more
@@ -106,84 +76,14 @@
// 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) {
- InlineQuality -= BB->size()*10 + 20;
- if (InlineQuality < 0) return false;
- }
+ BB != E; ++BB)
+ InlineCost += BB->size()*10 + 20;
// Don't inline into something too big, which would make it bigger. Here, we
// count each basic block as a single unit.
for (Function::const_iterator BB = Caller->begin(), E = Caller->end();
- BB != E; ++BB) {
- --InlineQuality;
- if (InlineQuality < 0) return false;
- }
+ BB != E; ++BB)
+ InlineCost++;
- // If we get here, this call site is high enough "quality" to inline.
- DEBUG(std::cerr << "Inlining in '" << Caller->getName()
- << "', quality = " << InlineQuality << ": " << *TheCall);
- return true;
+ return InlineCost;
}
-
-
-// doInlining - Use a heuristic based approach to inline functions that seem to
-// look good.
-//
-bool FunctionInlining::doInlining(Function *F) {
- // If we have already processed this function (ie, it is recursive) don't
- // revisit.
- std::set<Function*>::iterator PFI = ProcessedFunctions.lower_bound(F);
- if (PFI != ProcessedFunctions.end() && *PFI == F) return false;
-
- // Insert the function in the set so it doesn't get revisited.
- ProcessedFunctions.insert(PFI, F);
-
- bool Changed = false;
- for (Function::iterator BB = F->begin(); BB != F->end(); ++BB)
- for (BasicBlock::iterator I = BB->begin(); I != BB->end(); ) {
- bool ShouldInc = true;
- // Found a call or invoke instruction?
- if (isa<CallInst>(I) || isa<InvokeInst>(I)) {
- CallSite CS = CallSite::get(I);
- if (Function *Callee = CS.getCalledFunction()) {
- doInlining(Callee); // Inline in callees before callers!
-
- // Decide whether we should inline this function...
- if (ShouldInlineFunction(CS)) {
- // Save an iterator to the instruction before the call if it exists,
- // otherwise get an iterator at the end of the block... because the
- // call will be destroyed.
- //
- BasicBlock::iterator SI;
- if (I != BB->begin()) {
- SI = I; --SI; // Instruction before the call...
- } else {
- SI = BB->end();
- }
-
- // Attempt to inline the function...
- if (InlineFunction(CS)) {
- ++NumInlined;
- Changed = true;
- // Move to instruction before the call...
- I = (SI == BB->end()) ? BB->begin() : SI;
- ShouldInc = false; // Don't increment iterator until next time
-
- // If we inlined the last possible call site to the function,
- // delete the function body now.
- if (Callee->use_empty() &&
- (Callee->hasInternalLinkage()||Callee->hasLinkOnceLinkage())){
- F->getParent()->getFunctionList().erase(Callee);
- ++NumDeleted;
- if (Callee == F) return true;
- }
- }
- }
- }
- }
- if (ShouldInc) ++I;
- }
-
- return Changed;
-}
-
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