#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
-#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Attributes.h"
#include "llvm/Support/CFG.h"
-#include "llvm/Support/Compiler.h"
#include "llvm/Pass.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/SmallPtrSet.h"
STATISTIC(NumSimpl, "Number of blocks simplified");
namespace {
- struct VISIBILITY_HIDDEN CFGSimplifyPass : public FunctionPass {
+ struct CFGSimplifyPass : public FunctionPass {
static char ID; // Pass identification, replacement for typeid
CFGSimplifyPass() : FunctionPass(&ID) {}
/// ChangeToUnreachable - Insert an unreachable instruction before the specified
/// instruction, making it and the rest of the code in the block dead.
-static void ChangeToUnreachable(Instruction *I, LLVMContext* Context) {
+static void ChangeToUnreachable(Instruction *I) {
BasicBlock *BB = I->getParent();
// Loop over all of the successors, removing BB's entry from any PHI
// nodes.
for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
(*SI)->removePredecessor(BB);
- new UnreachableInst(I);
+ new UnreachableInst(I->getContext(), I);
// All instructions after this are dead.
BasicBlock::iterator BBI = I, BBE = BB->end();
while (BBI != BBE) {
if (!BBI->use_empty())
- BBI->replaceAllUsesWith(Context->getUndef(BBI->getType()));
+ BBI->replaceAllUsesWith(UndefValue::get(BBI->getType()));
BB->getInstList().erase(BBI++);
}
}
}
static bool MarkAliveBlocks(BasicBlock *BB,
- SmallPtrSet<BasicBlock*, 128> &Reachable,
- LLVMContext* Context) {
+ SmallPtrSet<BasicBlock*, 128> &Reachable) {
SmallVector<BasicBlock*, 128> Worklist;
Worklist.push_back(BB);
// though.
++BBI;
if (!isa<UnreachableInst>(BBI)) {
- ChangeToUnreachable(BBI, Context);
+ ChangeToUnreachable(BBI);
Changed = true;
}
break;
}
}
+ // Store to undef and store to null are undefined and used to signal that
+ // they should be changed to unreachable by passes that can't modify the
+ // CFG.
if (StoreInst *SI = dyn_cast<StoreInst>(BBI)) {
Value *Ptr = SI->getOperand(1);
if (isa<UndefValue>(Ptr) ||
(isa<ConstantPointerNull>(Ptr) &&
- cast<PointerType>(Ptr->getType())->getAddressSpace() == 0)) {
- ChangeToUnreachable(SI, Context);
+ SI->getPointerAddressSpace() == 0)) {
+ ChangeToUnreachable(SI);
Changed = true;
break;
}
/// otherwise.
static bool RemoveUnreachableBlocksFromFn(Function &F) {
SmallPtrSet<BasicBlock*, 128> Reachable;
- bool Changed = MarkAliveBlocks(F.begin(), Reachable, F.getContext());
+ bool Changed = MarkAliveBlocks(F.begin(), Reachable);
// If there are unreachable blocks in the CFG...
if (Reachable.size() == F.size())