-//===- MethodInlining.cpp - Code to perform method inlining ---------------===//
+//===- FunctionInlining.cpp - Code to perform function inlining -----------===//
//
-// This file implements inlining of methods.
+// This file implements inlining of functions.
//
// Specifically, this:
-// * Exports functionality to inline any method call
-// * Inlines methods that consist of a single basic block
-// * Is able to inline ANY method call
-// . Has a smart heuristic for when to inline a method
+// * Exports functionality to inline any function call
+// * Inlines functions that consist of a single basic block
+// * Is able to inline ANY function call
+// . Has a smart heuristic for when to inline a function
//
// Notice that:
-// * This pass has a habit of introducing duplicated constant pool entries,
-// and also opens up a lot of opportunities for constant propogation. It is
-// a good idea to to run a constant propogation pass, then a DCE pass
+// * This pass opens up a lot of opportunities for constant propogation. It
+// is a good idea to to run a constant propogation pass, then a DCE pass
// sometime after running this pass.
//
-// TODO: Currently this throws away all of the symbol names in the method being
-// inlined to try to avoid name clashes. Use a name if it's not taken
+// FIXME: This pass should transform alloca instructions in the called function
+// into malloc/free pairs!
//
//===----------------------------------------------------------------------===//
+#include "llvm/Transforms/MethodInlining.h"
#include "llvm/Module.h"
-#include "llvm/Method.h"
-#include "llvm/BasicBlock.h"
+#include "llvm/Function.h"
+#include "llvm/Pass.h"
#include "llvm/iTerminators.h"
+#include "llvm/iPHINode.h"
#include "llvm/iOther.h"
-#include "llvm/Opt/AllOpts.h"
+#include "llvm/Type.h"
+#include "llvm/Argument.h"
#include <algorithm>
#include <map>
-
-#include "llvm/Assembly/Writer.h"
+#include <iostream>
+using std::cerr;
// RemapInstruction - Convert the instruction operands from referencing the
// current values into those specified by ValueMap.
//
static inline void RemapInstruction(Instruction *I,
- map<const Value *, Value*> &ValueMap) {
+ std::map<const Value *, Value*> &ValueMap) {
- for (unsigned op = 0; const Value *Op = I->getOperand(op); op++) {
+ for (unsigned op = 0, E = I->getNumOperands(); op != E; ++op) {
+ const Value *Op = I->getOperand(op);
Value *V = ValueMap[Op];
- if (!V && Op->getValueType() == Value::MethodVal)
- continue; // Methods don't get relocated
+ if (!V && (isa<GlobalValue>(Op) || isa<Constant>(Op)))
+ continue; // Globals and constants don't get relocated
if (!V) {
- cerr << "Val = " << endl << Op << "Addr = " << (void*)Op << endl;
- cerr << "Inst = " << I;
+ cerr << "Val = \n" << Op << "Addr = " << (void*)Op;
+ cerr << "\nInst = " << I;
}
assert(V && "Referenced value not in value map!");
I->setOperand(op, V);
}
}
-// InlineMethod - This function forcibly inlines the called method into the
+// InlineMethod - This function forcibly inlines the called function into the
// basic block of the caller. This returns false if it is not possible to
// inline this call. The program is still in a well defined state if this
// occurs though.
// Note that this only does one level of inlining. For example, if the
// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
// exists in the instruction stream. Similiarly this will inline a recursive
-// method by one level.
+// function by one level.
//
-bool InlineMethod(BasicBlock::InstListType::iterator CIIt) {
- assert((*CIIt)->getInstType() == Instruction::Call &&
- "InlineMethod only works on CallInst nodes!");
+bool InlineMethod(BasicBlock::iterator CIIt) {
+ assert(isa<CallInst>(*CIIt) && "InlineMethod only works on CallInst nodes!");
assert((*CIIt)->getParent() && "Instruction not embedded in basic block!");
- assert((*CIIt)->getParent()->getParent() && "Instruction not in method!");
+ assert((*CIIt)->getParent()->getParent() && "Instruction not in function!");
- CallInst *CI = (CallInst*)*CIIt;
- const Method *CalledMeth = CI->getCalledMethod();
- Method *CurrentMeth = CI->getParent()->getParent();
+ CallInst *CI = cast<CallInst>(*CIIt);
+ const Function *CalledMeth = CI->getCalledFunction();
+ if (CalledMeth == 0 || // Can't inline external function or indirect call!
+ CalledMeth->isExternal()) return false;
//cerr << "Inlining " << CalledMeth->getName() << " into "
- // << CurrentMeth->getName() << endl;
+ // << CurrentMeth->getName() << "\n";
BasicBlock *OrigBB = CI->getParent();
// unconditional branch to NewBB, and NewBB starts with the call instruction.
//
BasicBlock *NewBB = OrigBB->splitBasicBlock(CIIt);
+ NewBB->setName("InlinedFunctionReturnNode");
// Remove (unlink) the CallInst from the start of the new basic block.
NewBB->getInstList().remove(CI);
// If we have a return value generated by this call, convert it into a PHI
// node that gets values from each of the old RET instructions in the original
- // method.
+ // function.
//
PHINode *PHI = 0;
if (CalledMeth->getReturnType() != Type::VoidTy) {
CI->replaceAllUsesWith(PHI);
}
- // Keep a mapping between the original method's values and the new duplicated
- // code's values. This includes all of: Method arguments, instruction values,
- // constant pool entries, and basic blocks.
+ // Keep a mapping between the original function's values and the new
+ // duplicated code's values. This includes all of: Function arguments,
+ // instruction values, constant pool entries, and basic blocks.
//
- map<const Value *, Value*> ValueMap;
+ std::map<const Value *, Value*> ValueMap;
- // Add the method arguments to the mapping: (start counting at 1 to skip the
- // method reference itself)
+ // Add the function arguments to the mapping: (start counting at 1 to skip the
+ // function reference itself)
//
- Method::ArgumentListType::const_iterator PTI =
+ Function::ArgumentListType::const_iterator PTI =
CalledMeth->getArgumentList().begin();
- for (unsigned a = 1; Value *Operand = CI->getOperand(a); ++a, ++PTI) {
- ValueMap[*PTI] = Operand;
- }
+ for (unsigned a = 1, E = CI->getNumOperands(); a != E; ++a, ++PTI)
+ ValueMap[*PTI] = CI->getOperand(a);
-
ValueMap[NewBB] = NewBB; // Returns get converted to reference NewBB
- // Loop over all of the basic blocks in the method, inlining them as
- // appropriate. Keep track of the first basic block of the method...
+ // Loop over all of the basic blocks in the function, inlining them as
+ // appropriate. Keep track of the first basic block of the function...
//
- for (Method::BasicBlocksType::const_iterator BI =
- CalledMeth->getBasicBlocks().begin();
- BI != CalledMeth->getBasicBlocks().end(); BI++) {
+ for (Function::const_iterator BI = CalledMeth->begin();
+ BI != CalledMeth->end(); ++BI) {
const BasicBlock *BB = *BI;
assert(BB->getTerminator() && "BasicBlock doesn't have terminator!?!?");
// Create a new basic block to copy instructions into!
BasicBlock *IBB = new BasicBlock("", NewBB->getParent());
+ if (BB->hasName()) IBB->setName(BB->getName()+".i"); // .i = inlined once
- ValueMap[*BI] = IBB; // Add basic block mapping.
+ ValueMap[BB] = IBB; // Add basic block mapping.
// Make sure to capture the mapping that a return will use...
// TODO: This assumes that the RET is returning a value computed in the same
// Loop over all instructions copying them over...
Instruction *NewInst;
- for (BasicBlock::InstListType::const_iterator II = BB->getInstList().begin();
- II != (BB->getInstList().end()-1); II++) {
+ for (BasicBlock::const_iterator II = BB->begin();
+ II != (BB->end()-1); ++II) {
IBB->getInstList().push_back((NewInst = (*II)->clone()));
ValueMap[*II] = NewInst; // Add instruction map to value.
+ if ((*II)->hasName())
+ NewInst->setName((*II)->getName()+".i"); // .i = inlined once
}
// Copy over the terminator now...
- switch (TI->getInstType()) {
+ switch (TI->getOpcode()) {
case Instruction::Ret: {
- const ReturnInst *RI = (const ReturnInst*)TI;
+ const ReturnInst *RI = cast<const ReturnInst>(TI);
if (PHI) { // The PHI node should include this value!
assert(RI->getReturnValue() && "Ret should have value!");
assert(RI->getReturnValue()->getType() == PHI->getType() &&
- "Ret value not consistent in method!");
- PHI->addIncoming((Value*)RI->getReturnValue(), (BasicBlock*)BB);
+ "Ret value not consistent in function!");
+ PHI->addIncoming((Value*)RI->getReturnValue(), cast<BasicBlock>(BB));
}
// Add a branch to the code that was after the original Call.
break;
default:
- cerr << "MethodInlining: Don't know how to handle terminator: " << TI;
+ cerr << "FunctionInlining: Don't know how to handle terminator: " << TI;
abort();
}
}
- // Copy over the constant pool...
- //
- const ConstantPool &CP = CalledMeth->getConstantPool();
- ConstantPool &NewCP = CurrentMeth->getConstantPool();
- for (ConstantPool::plane_const_iterator PI = CP.begin(); PI != CP.end(); ++PI){
- ConstantPool::PlaneType &Plane = **PI;
- for (ConstantPool::PlaneType::const_iterator I = Plane.begin();
- I != Plane.end(); ++I) {
- ConstPoolVal *NewVal = (*I)->clone(); // Copy existing constant
- NewCP.insert(NewVal); // Insert the new copy into local const pool
- ValueMap[*I] = NewVal; // Keep track of constant value mappings
- }
- }
-
- // Loop over all of the instructions in the method, fixing up operand
+ // Loop over all of the instructions in the function, fixing up operand
// references as we go. This uses ValueMap to do all the hard work.
//
- for (Method::BasicBlocksType::const_iterator BI =
- CalledMeth->getBasicBlocks().begin();
- BI != CalledMeth->getBasicBlocks().end(); BI++) {
+ for (Function::const_iterator BI = CalledMeth->begin();
+ BI != CalledMeth->end(); ++BI) {
const BasicBlock *BB = *BI;
BasicBlock *NBB = (BasicBlock*)ValueMap[BB];
// Loop over all instructions, fixing each one as we find it...
//
- for (BasicBlock::InstListType::iterator II = NBB->getInstList().begin();
- II != NBB->getInstList().end(); II++)
+ for (BasicBlock::iterator II = NBB->begin(); II != NBB->end(); II++)
RemapInstruction(*II, ValueMap);
}
if (PHI) RemapInstruction(PHI, ValueMap); // Fix the PHI node also...
// Change the branch that used to go to NewBB to branch to the first basic
- // block of the inlined method.
+ // block of the inlined function.
//
TerminatorInst *Br = OrigBB->getTerminator();
- assert(Br && Br->getInstType() == Instruction::Br &&
+ assert(Br && Br->getOpcode() == Instruction::Br &&
"splitBasicBlock broken!");
- Br->setOperand(0, ValueMap[CalledMeth->getBasicBlocks().front()]);
+ Br->setOperand(0, ValueMap[CalledMeth->front()]);
// Since we are now done with the CallInst, we can finally delete it.
delete CI;
assert(CI->getParent() && "CallInst not embeded in BasicBlock!");
BasicBlock *PBB = CI->getParent();
- BasicBlock::InstListType::iterator CallIt = find(PBB->getInstList().begin(),
- PBB->getInstList().end(),
- CI);
- assert(CallIt != PBB->getInstList().end() &&
+ BasicBlock::iterator CallIt = find(PBB->begin(), PBB->end(), CI);
+
+ assert(CallIt != PBB->end() &&
"CallInst has parent that doesn't contain CallInst?!?");
return InlineMethod(CallIt);
}
-static inline bool ShouldInlineMethod(const CallInst *CI, const Method *M) {
+static inline bool ShouldInlineFunction(const CallInst *CI, const Function *F) {
assert(CI->getParent() && CI->getParent()->getParent() &&
"Call not embedded into a method!");
// Don't inline a recursive call.
- if (CI->getParent()->getParent() == M) return false;
+ if (CI->getParent()->getParent() == F) return false;
// Don't inline something too big. This is a really crappy heuristic
- if (M->getBasicBlocks().size() > 3) return false;
+ if (F->size() > 3) return false;
// Don't inline into something too big. This is a **really** crappy heuristic
- if (CI->getParent()->getParent()->getBasicBlocks().size() > 10) return false;
+ if (CI->getParent()->getParent()->size() > 10) return false;
// Go ahead and try just about anything else.
return true;
}
-static inline bool DoMethodInlining(BasicBlock *BB) {
- for (BasicBlock::InstListType::iterator I = BB->getInstList().begin();
- I != BB->getInstList().end(); I++) {
- if ((*I)->getInstType() == Instruction::Call) {
- // Check to see if we should inline this method
- CallInst *CI = (CallInst*)*I;
- Method *M = CI->getCalledMethod();
- if (ShouldInlineMethod(CI, M))
+static inline bool DoFunctionInlining(BasicBlock *BB) {
+ for (BasicBlock::iterator I = BB->begin(); I != BB->end(); ++I) {
+ if (CallInst *CI = dyn_cast<CallInst>(*I)) {
+ // Check to see if we should inline this function
+ Function *F = CI->getCalledFunction();
+ if (F && ShouldInlineFunction(CI, F))
return InlineMethod(I);
}
}
return false;
}
-bool DoMethodInlining(Method *M) {
- Method::BasicBlocksType &BBs = M->getBasicBlocks();
+// doFunctionInlining - Use a heuristic based approach to inline functions that
+// seem to look good.
+//
+static bool doFunctionInlining(Function *F) {
bool Changed = false;
// Loop through now and inline instructions a basic block at a time...
- for (Method::BasicBlocksType::iterator I = BBs.begin(); I != BBs.end(); )
- if (DoMethodInlining(*I)) {
+ for (Function::iterator I = F->begin(); I != F->end(); )
+ if (DoFunctionInlining(*I)) {
Changed = true;
// Iterator is now invalidated by new basic blocks inserted
- I = BBs.begin();
+ I = F->begin();
} else {
++I;
}
return Changed;
}
+
+namespace {
+ struct FunctionInlining : public MethodPass {
+ virtual bool runOnMethod(Function *F) {
+ return doFunctionInlining(F);
+ }
+ };
+}
+
+Pass *createMethodInliningPass() { return new FunctionInlining(); }