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-rw-r--r--lib/VMCore/BasicBlock.cpp113
1 files changed, 113 insertions, 0 deletions
diff --git a/lib/VMCore/BasicBlock.cpp b/lib/VMCore/BasicBlock.cpp
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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;
+}