-//===-- BasicBlock.cpp - Implement BasicBlock related functions --*- C++ -*--=//
+//===-- BasicBlock.cpp - Implement BasicBlock related methods -------------===//
//
// This file implements the BasicBlock class for the VMCore library.
//
//===----------------------------------------------------------------------===//
-#include "ValueHolderImpl.h"
+#include "llvm/BasicBlock.h"
#include "llvm/iTerminators.h"
#include "llvm/Type.h"
#include "llvm/Support/CFG.h"
+#include "llvm/Constant.h"
#include "llvm/iPHINode.h"
-#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/SymbolTable.h"
+#include "Support/LeakDetector.h"
+#include "SymbolTableListTraitsImpl.h"
+#include <algorithm>
-// Instantiate Templates - This ugliness is the price we have to pay
-// for having a ValueHolderImpl.h file seperate from ValueHolder.h! :(
+// DummyInst - An instance of this class is used to mark the end of the
+// instruction list. This is not a real instruction.
//
-template class ValueHolder<Instruction, BasicBlock, Function>;
+struct DummyInst : public Instruction {
+ DummyInst() : Instruction(Type::VoidTy, OtherOpsEnd) {
+ // This should not be garbage monitored.
+ LeakDetector::removeGarbageObject(this);
+ }
+
+ virtual Instruction *clone() const {
+ assert(0 && "Cannot clone EOL");abort();
+ return 0;
+ }
+ virtual const char *getOpcodeName() const { return "*end-of-list-inst*"; }
+
+ // Methods for support type inquiry through isa, cast, and dyn_cast...
+ static inline bool classof(const DummyInst *) { return true; }
+ static inline bool classof(const Instruction *I) {
+ return I->getOpcode() == OtherOpsEnd;
+ }
+ static inline bool classof(const Value *V) {
+ return isa<Instruction>(V) && classof(cast<Instruction>(V));
+ }
+};
+
+Instruction *ilist_traits<Instruction>::createNode() {
+ return new DummyInst();
+}
+iplist<Instruction> &ilist_traits<Instruction>::getList(BasicBlock *BB) {
+ return BB->getInstList();
+}
+// Explicit instantiation of SymbolTableListTraits since some of the methods
+// are not in the public header file...
+template SymbolTableListTraits<Instruction, BasicBlock, Function>;
+
+
+// BasicBlock ctor - If the function parameter is specified, the basic block is
+// automatically inserted at the end of the function.
+//
BasicBlock::BasicBlock(const std::string &name, Function *Parent)
- : Value(Type::LabelTy, Value::BasicBlockVal, name), InstList(this, 0),
- machineInstrVec(new MachineCodeForBasicBlock) {
+ : Value(Type::LabelTy, Value::BasicBlockVal, name) {
+ // Initialize the instlist...
+ InstList.setItemParent(this);
+
+ // Make sure that we get added to a function
+ LeakDetector::addGarbageObject(this);
+
if (Parent)
- Parent->getBasicBlocks().push_back(this);
+ Parent->getBasicBlockList().push_back(this);
}
+/// BasicBlock ctor - If the InsertBefore parameter is specified, the basic
+/// block is automatically inserted right before the specified block.
+///
+BasicBlock::BasicBlock(const std::string &Name, BasicBlock *InsertBefore)
+ : Value(Type::LabelTy, Value::BasicBlockVal, Name) {
+ // Initialize the instlist...
+ InstList.setItemParent(this);
+
+ // Make sure that we get added to a function
+ LeakDetector::addGarbageObject(this);
+
+ if (InsertBefore) {
+ assert(InsertBefore->getParent() &&
+ "Cannot insert block before another block that is not embedded into"
+ " a function yet!");
+ InsertBefore->getParent()->getBasicBlockList().insert(InsertBefore, this);
+ }
+}
+
+
BasicBlock::~BasicBlock() {
dropAllReferences();
- InstList.delete_all();
- delete machineInstrVec;
+ InstList.clear();
+}
+
+void BasicBlock::setParent(Function *parent) {
+ if (getParent())
+ LeakDetector::addGarbageObject(this);
+
+ InstList.setParent(parent);
+
+ if (getParent())
+ LeakDetector::removeGarbageObject(this);
}
// Specialize setName to take care of symbol table majik
void BasicBlock::setName(const std::string &name, SymbolTable *ST) {
Function *P;
- assert((ST == 0 || (!getParent() || ST == getParent()->getSymbolTable())) &&
+ assert((ST == 0 || (!getParent() || ST == &getParent()->getSymbolTable())) &&
"Invalid symtab argument!");
- if ((P = getParent()) && hasName()) P->getSymbolTable()->remove(this);
+ if ((P = getParent()) && hasName()) P->getSymbolTable().remove(this);
Value::setName(name);
- if (P && hasName()) P->getSymbolTable()->insert(this);
-}
-
-void BasicBlock::setParent(Function *parent) {
- if (getParent() && hasName())
- getParent()->getSymbolTable()->remove(this);
-
- InstList.setParent(parent);
-
- if (getParent() && hasName())
- getParent()->getSymbolTableSure()->insert(this);
+ if (P && hasName()) P->getSymbolTable().insert(this);
}
TerminatorInst *BasicBlock::getTerminator() {
if (InstList.empty()) return 0;
- Instruction *T = InstList.back();
- if (isa<TerminatorInst>(T)) return cast<TerminatorInst>(T);
- return 0;
+ return dyn_cast<TerminatorInst>(&InstList.back());
}
const TerminatorInst *const BasicBlock::getTerminator() const {
if (InstList.empty()) return 0;
- if (const TerminatorInst *TI = dyn_cast<TerminatorInst>(InstList.back()))
- return TI;
- return 0;
+ return dyn_cast<TerminatorInst>(&InstList.back());
}
void BasicBlock::dropAllReferences() {
- for_each(InstList.begin(), InstList.end(),
- std::mem_fun(&Instruction::dropAllReferences));
+ for(iterator I = begin(), E = end(); I != E; ++I)
+ I->dropAllReferences();
}
// hasConstantReferences() - This predicate is true if there is a
for (max_idx = 0; PI != EI && max_idx < 3; ++PI, ++max_idx) /*empty*/;
// If there are exactly two predecessors, then we want to nuke the PHI nodes
- // altogether.
+ // altogether. We cannot do this, however if this in this case however:
+ //
+ // Loop:
+ // %x = phi [X, Loop]
+ // %x2 = add %x, 1 ;; This would become %x2 = add %x2, 1
+ // br Loop ;; %x2 does not dominate all uses
+ //
+ // This is because the PHI node input is actually taken from the predecessor
+ // basic block. The only case this can happen is with a self loop, so we
+ // check for this case explicitly now.
+ //
assert(max_idx != 0 && "PHI Node in block with 0 predecessors!?!?!");
+ if (max_idx == 2) {
+ PI = pred_begin(this);
+ BasicBlock *Other = *PI == Pred ? *++PI : *PI;
+
+ // Disable PHI elimination!
+ if (this == Other) max_idx = 3;
+ }
+
if (max_idx <= 2) { // <= Two predecessors BEFORE I remove one?
// Yup, loop through and nuke the PHI nodes
- while (PHINode *PN = dyn_cast<PHINode>(front())) {
+ while (PHINode *PN = dyn_cast<PHINode>(&front())) {
PN->removeIncomingValue(Pred); // Remove the predecessor first...
-
- assert(PN->getNumIncomingValues() == max_idx-1 &&
- "PHI node shouldn't have this many values!!!");
// If the PHI _HAD_ two uses, replace PHI node with its now *single* value
- if (max_idx == 2)
+ if (max_idx == 2) {
PN->replaceAllUsesWith(PN->getOperand(0));
- delete getInstList().remove(begin()); // Remove the PHI node
+ getInstList().pop_front(); // Remove the PHI node
+ }
+
+ // If the PHI node already only had one entry, it got deleted by
+ // removeIncomingValue.
}
} else {
// Okay, now we know that we need to remove predecessor #pred_idx from all
// PHI nodes. Iterate over each PHI node fixing them up
- iterator II(begin());
- for (; isa<PHINode>(*II); ++II)
- cast<PHINode>(*II)->removeIncomingValue(Pred);
+ for (iterator II = begin(); PHINode *PN = dyn_cast<PHINode>(&*II); ++II)
+ PN->removeIncomingValue(Pred);
}
}
iterator EndIt = 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.
+ } 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));
// incoming values...
BasicBlock *Successor = *I;
for (BasicBlock::iterator II = Successor->begin();
- PHINode *PN = dyn_cast<PHINode>(*II); ++II) {
+ PHINode *PN = dyn_cast<PHINode>(&*II); ++II) {
int IDX = PN->getBasicBlockIndex(this);
while (IDX != -1) {
PN->setIncomingBlock((unsigned)IDX, New);
projects / oota-llvm.git / blobdiff