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//===-- BasicBlock.cpp - Implement BasicBlock related functions --*- C++ -*--=//
//
// This file implements the Method class for the VMCore library.
//
//===----------------------------------------------------------------------===//
#include "llvm/ValueHolderImpl.h"
#include "llvm/BasicBlock.h"
#include "llvm/iTerminators.h"
#include "llvm/Module.h"
#include "llvm/Method.h"
#include "llvm/SymbolTable.h"
#include "llvm/Type.h"
// Instantiate Templates - This ugliness is the price we have to pay
// for having a ValueHolderImpl.h file seperate from ValueHolder.h! :(
//
template class ValueHolder<Instruction, BasicBlock>;
BasicBlock::BasicBlock(const string &name, Method *parent)
: Value(Type::LabelTy, Value::BasicBlockVal, name), InstList(this, 0) {
if (parent)
parent->getBasicBlocks().push_back(this);
}
BasicBlock::~BasicBlock() {
dropAllReferences();
InstList.delete_all();
}
// Specialize setName to take care of symbol table majik
void BasicBlock::setName(const string &name) {
Method *P;
if ((P = getParent()) && hasName()) P->getSymbolTable()->remove(this);
Value::setName(name);
if (P && hasName()) P->getSymbolTable()->insert(this);
}
void BasicBlock::setParent(Method *parent) {
if (getParent() && hasName())
getParent()->getSymbolTable()->remove(this);
InstList.setParent(parent);
if (getParent() && hasName())
getParent()->getSymbolTableSure()->insert(this);
}
TerminatorInst *BasicBlock::getTerminator() {
if (InstList.empty()) return 0;
Instruction *T = InstList.back();
if (T->isTerminator()) return (TerminatorInst*)T;
return 0;
}
const TerminatorInst *const BasicBlock::getTerminator() const {
if (InstList.empty()) return 0;
const Instruction *T = InstList.back();
if (T->isTerminator()) return (TerminatorInst*)T;
return 0;
}
void BasicBlock::dropAllReferences() {
for_each(InstList.begin(), InstList.end(),
std::mem_fun(&Instruction::dropAllReferences));
}
// hasConstantPoolReferences() - This predicate is true if there is a
// reference to this basic block in the constant pool for this method. For
// example, if a block is reached through a switch table, that table resides
// in the constant pool, and the basic block is reference from it.
//
bool BasicBlock::hasConstantPoolReferences() const {
for (use_const_iterator I = use_begin(), E = use_end(); I != E; ++I)
if ((*I)->getValueType() == ConstantVal)
return true;
return false;
}
// splitBasicBlock - This splits a basic block into two at the specified
// instruction. Note that all instructions BEFORE the specified iterator stay
// as part of the original basic block, an unconditional branch is added to
// the new BB, and the rest of the instructions in the BB are moved to the new
// BB, including the old terminator. This invalidates the iterator.
//
// Note that this only works on well formed basic blocks (must have a
// terminator), and 'I' must not be the end of instruction list (which would
// cause a degenerate basic block to be formed, having a terminator inside of
// the basic block).
//
BasicBlock *BasicBlock::splitBasicBlock(InstListType::iterator I) {
assert(getTerminator() && "Can't use splitBasicBlock on degenerate BB!");
assert(I != InstList.end() &&
"Trying to get me to create degenerate basic block!");
BasicBlock *New = new BasicBlock("", getParent());
// Go from the end of the basic block through to the iterator pointer, moving
// to the new basic block...
Instruction *Inst = 0;
do {
InstListType::iterator EndIt = InstList.end();
Inst = InstList.remove(--EndIt); // Remove from end
New->InstList.push_front(Inst); // Add to front
} while (Inst != *I); // Loop until we move the specified instruction.
// Add a branch instruction to the newly formed basic block.
InstList.push_back(new BranchInst(New));
return New;
}
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