Rework inline pass to use cloning infrastructure to do the dirty work

llvm-svn: 4766
This commit is contained in:
Chris Lattner 2002-11-19 21:54:07 +00:00
parent 891bbab848
commit b1120055b9
2 changed files with 52 additions and 119 deletions

View File

@ -32,27 +32,6 @@
static Statistic<> NumInlined("inline", "Number of functions inlined");
using std::cerr;
// RemapInstruction - Convert the instruction operands from referencing the
// current values into those specified by ValueMap.
//
static inline void RemapInstruction(Instruction *I,
std::map<const Value *, Value*> &ValueMap) {
for (unsigned op = 0, E = I->getNumOperands(); op != E; ++op) {
const Value *Op = I->getOperand(op);
Value *V = ValueMap[Op];
if (!V && (isa<GlobalValue>(Op) || isa<Constant>(Op)))
continue; // Globals and constants don't get relocated
if (!V) {
cerr << "Val = \n" << Op << "Addr = " << (void*)Op;
cerr << "\nInst = " << I;
}
assert(V && "Referenced value not in value map!");
I->setOperand(op, V);
}
}
// InlineFunction - 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
@ -92,7 +71,7 @@ bool InlineFunction(CallInst *CI) {
// function.
//
PHINode *PHI = 0;
if (CalledFunc->getReturnType() != Type::VoidTy) {
if (!CI->use_empty()) {
// The PHI node should go at the front of the new basic block to merge all
// possible incoming values.
//
@ -105,103 +84,53 @@ bool InlineFunction(CallInst *CI) {
CI->replaceAllUsesWith(PHI);
}
// 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.
// Get a pointer to the last basic block in the function, which will have the
// new function inlined after it.
//
std::map<const Value *, Value*> ValueMap;
Function::iterator LastBlock = &OrigBB->getParent()->back();
// Add the function arguments to the mapping: (start counting at 1 to skip the
// function reference itself)
//
Function::const_aiterator PTI = CalledFunc->abegin();
for (unsigned a = 1, E = CI->getNumOperands(); a != E; ++a, ++PTI)
ValueMap[PTI] = CI->getOperand(a);
// Calculate the vector of arguments to pass into the function cloner...
std::vector<Value*> ArgVector;
for (unsigned i = 1, e = CI->getNumOperands(); i != e; ++i)
ArgVector.push_back(CI->getOperand(i));
ValueMap[NewBB] = NewBB; // Returns get converted to reference NewBB
// Since we are now done with the CallInst, we can delete it.
delete CI;
// 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 (Function::const_iterator BB = CalledFunc->begin();
BB != CalledFunc->end(); ++BB) {
assert(BB->getTerminator() && "BasicBlock doesn't have terminator!?!?");
// Make a vector to capture the return instructions in the cloned function...
std::vector<ReturnInst*> Returns;
// 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
// Do all of the hard part of cloning the callee into the caller...
CloneFunctionInto(OrigBB->getParent(), CalledFunc, ArgVector, Returns, ".i");
ValueMap[BB] = IBB; // Add basic block mapping.
// Loop over all of the return instructions, turning them into unconditional
// branches to the merge point now...
for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
ReturnInst *RI = Returns[i];
BasicBlock *BB = RI->getParent();
// 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
// basic block as the return was issued from!
//
const TerminatorInst *TI = BB->getTerminator();
// Loop over all instructions copying them over...
Instruction *NewInst;
for (BasicBlock::const_iterator II = BB->begin();
II != --BB->end(); ++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->getOpcode()) {
case Instruction::Ret: {
const ReturnInst *RI = cast<ReturnInst>(TI);
// Add a branch to the merge point where the PHI node would live...
new BranchInst(NewBB, RI);
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 function!");
PHI->addIncoming((Value*)RI->getReturnValue(),
(BasicBlock*)cast<BasicBlock>(&*BB));
PHI->addIncoming(RI->getReturnValue(), BB);
}
// Add a branch to the code that was after the original Call.
IBB->getInstList().push_back(new BranchInst(NewBB));
break;
// Delete the return instruction now
BB->getInstList().erase(RI);
}
case Instruction::Br:
IBB->getInstList().push_back(TI->clone());
break;
default:
cerr << "FunctionInlining: Don't know how to handle terminator: " << TI;
abort();
}
}
// 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 (Function::const_iterator BB = CalledFunc->begin();
BB != CalledFunc->end(); ++BB) {
BasicBlock *NBB = (BasicBlock*)ValueMap[BB];
// Loop over all instructions, fixing each one as we find it...
//
for (BasicBlock::iterator II = NBB->begin(); II != NBB->end(); ++II)
RemapInstruction(II, ValueMap);
}
if (PHI) {
RemapInstruction(PHI, ValueMap); // Fix the PHI node also...
// Check to see if the PHI node only has one argument. This is a common
// case resulting from there only being a single return instruction in the
// function call. Because this is so common, eliminate the PHI node.
//
if (PHI->getNumIncomingValues() == 1) {
if (PHI && PHI->getNumIncomingValues() == 1) {
PHI->replaceAllUsesWith(PHI->getIncomingValue(0));
PHI->getParent()->getInstList().erase(PHI);
}
}
// Change the branch that used to go to NewBB to branch to the first basic
// block of the inlined function.
@ -209,10 +138,7 @@ bool InlineFunction(CallInst *CI) {
TerminatorInst *Br = OrigBB->getTerminator();
assert(Br && Br->getOpcode() == Instruction::Br &&
"splitBasicBlock broken!");
Br->setOperand(0, ValueMap[&CalledFunc->front()]);
// Since we are now done with the CallInst, we can finally delete it.
delete CI;
Br->setOperand(0, ++LastBlock);
return true;
}

View File

@ -4,6 +4,7 @@
// FIXME: document
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/iTerminators.h"
#include "llvm/Function.h"
#include <map>
@ -35,9 +36,10 @@ static inline void RemapInstruction(Instruction *I,
// ArgMap values.
//
void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
const std::vector<Value*> &ArgMap) {
assert(OldFunc->aempty() || !NewFunc->aempty() &&
"Synthesization of arguments is not implemented yet!");
const std::vector<Value*> &ArgMap,
std::vector<ReturnInst*> &Returns,
const char *NameSuffix) {
assert(NameSuffix && "NameSuffix cannot be null!");
assert(OldFunc->asize() == ArgMap.size() &&
"Improper number of argument values to map specified!");
@ -55,25 +57,30 @@ void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
// Loop over all of the basic blocks in the function, cloning them as
// appropriate.
// appropriate. Note that we save BE this way in order to handle cloning of
// recursive functions into themselves.
//
for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
BI != BE; ++BI) {
const BasicBlock &BB = *BI;
assert(BB.getTerminator() && "BasicBlock doesn't have terminator!?!?");
// Create a new basic block to copy instructions into!
BasicBlock *CBB = new BasicBlock(BB.getName(), NewFunc);
BasicBlock *CBB = new BasicBlock("", NewFunc);
if (BB.hasName()) CBB->setName(BB.getName()+NameSuffix);
ValueMap[&BB] = CBB; // Add basic block mapping.
// Loop over all instructions copying them over...
for (BasicBlock::const_iterator II = BB.begin(), IE = BB.end();
II != IE; ++II) {
Instruction *NewInst = II->clone();
NewInst->setName(II->getName()); // Name is not cloned...
if (II->hasName())
NewInst->setName(II->getName()+NameSuffix); // Name is not cloned...
CBB->getInstList().push_back(NewInst);
ValueMap[II] = NewInst; // Add instruction map to value.
}
if (ReturnInst *RI = dyn_cast<ReturnInst>(CBB->getTerminator()))
Returns.push_back(RI);
}
// Loop over all of the instructions in the function, fixing up operand