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factor duplicated code into a new DeleteInstructionInBlock

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function, eliminate temporary (and pointless) smallvector.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85776 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2009-11-02 02:47:51 +00:00
parent 2f09625a9f
commit cc4f60b113
1 changed files with 83 additions and 95 deletions
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178
lib/Transforms/Scalar/SCCP.cpp
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@ -47,7 +47,6 @@ STATISTIC(NumInstRemoved, "Number of instructions removed");
STATISTIC(NumDeadBlocks , "Number of basic blocks unreachable");
STATISTIC(IPNumInstRemoved, "Number of instructions removed by IPSCCP");
STATISTIC(IPNumDeadBlocks , "Number of basic blocks unreachable by IPSCCP");
STATISTIC(IPNumArgsElimed ,"Number of arguments constant propagated by IPSCCP");
STATISTIC(IPNumGlobalConst, "Number of globals found to be constant by IPSCCP");
@ -136,6 +135,10 @@ public:
Val.setPointer(V);
}
};
} // end anonymous namespace.
namespace {
//===----------------------------------------------------------------------===//
//
@ -380,7 +383,6 @@ private:
// visit implementations - Something changed in this instruction. Either an
// operand made a transition, or the instruction is newly executable. Change
// the value type of I to reflect these changes if appropriate.
//
void visitPHINode(PHINode &I);
// Terminators
@ -1566,6 +1568,21 @@ FunctionPass *llvm::createSCCPPass() {
return new SCCP();
}
static void DeleteInstructionInBlock(BasicBlock *BB) {
DEBUG(errs() << " BasicBlock Dead:" << *BB);
++NumDeadBlocks;
// Delete the instructions backwards, as it has a reduced likelihood of
// having to update as many def-use and use-def chains.
while (!isa<TerminatorInst>(BB->begin())) {
Instruction *I = --BasicBlock::iterator(BB->getTerminator());
if (!I->use_empty())
I->replaceAllUsesWith(UndefValue::get(I->getType()));
BB->getInstList().erase(I);
++NumInstRemoved;
}
}
// runOnFunction() - Run the Sparse Conditional Constant Propagation algorithm,
// and return true if the function was modified.
@ -1595,56 +1612,42 @@ bool SCCP::runOnFunction(Function &F) {
// delete their contents now. Note that we cannot actually delete the blocks,
// as we cannot modify the CFG of the function.
//
SmallVector<Instruction*, 512> Insts;
std::map<Value*, LatticeVal> &Values = Solver.getValueMapping();
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
if (!Solver.isBlockExecutable(BB)) {
DEBUG(errs() << " BasicBlock Dead:" << *BB);
++NumDeadBlocks;
// Delete the instructions backwards, as it has a reduced likelihood of
// having to update as many def-use and use-def chains.
for (BasicBlock::iterator I = BB->begin(), E = BB->getTerminator();
I != E; ++I)
Insts.push_back(I);
while (!Insts.empty()) {
Instruction *I = Insts.back();
Insts.pop_back();
if (!I->use_empty())
I->replaceAllUsesWith(UndefValue::get(I->getType()));
BB->getInstList().erase(I);
MadeChanges = true;
++NumInstRemoved;
}
} else {
// Iterate over all of the instructions in a function, replacing them with
// constants if we have found them to be of constant values.
//
for (BasicBlock::iterator BI = BB->begin(), E = BB->end(); BI != E; ) {
Instruction *Inst = BI++;
if (Inst->getType()->isVoidTy() || isa<TerminatorInst>(Inst))
continue;
LatticeVal &IV = Values[Inst];
if (!IV.isConstant() && !IV.isUndefined())
continue;
Constant *Const = IV.isConstant()
? IV.getConstant() : UndefValue::get(Inst->getType());
DEBUG(errs() << " Constant: " << *Const << " = " << *Inst);
// Replaces all of the uses of a variable with uses of the constant.
Inst->replaceAllUsesWith(Const);
// Delete the instruction.
Inst->eraseFromParent();
// Hey, we just changed something!
MadeChanges = true;
++NumInstRemoved;
}
DeleteInstructionInBlock(BB);
MadeChanges = true;
continue;
}
// Iterate over all of the instructions in a function, replacing them with
// constants if we have found them to be of constant values.
//
for (BasicBlock::iterator BI = BB->begin(), E = BB->end(); BI != E; ) {
Instruction *Inst = BI++;
if (Inst->getType()->isVoidTy() || isa<TerminatorInst>(Inst))
continue;
LatticeVal &IV = Values[Inst];
if (!IV.isConstant() && !IV.isUndefined())
continue;
Constant *Const = IV.isConstant()
? IV.getConstant() : UndefValue::get(Inst->getType());
DEBUG(errs() << " Constant: " << *Const << " = " << *Inst);
// Replaces all of the uses of a variable with uses of the constant.
Inst->replaceAllUsesWith(Const);
// Delete the instruction.
Inst->eraseFromParent();
// Hey, we just changed something!
MadeChanges = true;
++NumInstRemoved;
}
}
return MadeChanges;
}
@ -1738,7 +1741,6 @@ bool IPSCCP::runOnModule(Module &M) {
// Iterate over all of the instructions in the module, replacing them with
// constants if we have found them to be of constant values.
//
SmallVector<Instruction*, 512> Insts;
SmallVector<BasicBlock*, 512> BlocksToErase;
std::map<Value*, LatticeVal> &Values = Solver.getValueMapping();
@ -1759,27 +1761,12 @@ bool IPSCCP::runOnModule(Module &M) {
}
}
for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
if (!Solver.isBlockExecutable(BB)) {
DEBUG(errs() << " BasicBlock Dead:" << *BB);
++IPNumDeadBlocks;
DeleteInstructionInBlock(BB);
MadeChanges = true;
// Delete the instructions backwards, as it has a reduced likelihood of
// having to update as many def-use and use-def chains.
TerminatorInst *TI = BB->getTerminator();
for (BasicBlock::iterator I = BB->begin(), E = TI; I != E; ++I)
Insts.push_back(I);
while (!Insts.empty()) {
Instruction *I = Insts.back();
Insts.pop_back();
if (!I->use_empty())
I->replaceAllUsesWith(UndefValue::get(I->getType()));
BB->getInstList().erase(I);
MadeChanges = true;
++IPNumInstRemoved;
}
for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i) {
BasicBlock *Succ = TI->getSuccessor(i);
if (!Succ->empty() && isa<PHINode>(Succ->begin()))
@ -1787,40 +1774,41 @@ bool IPSCCP::runOnModule(Module &M) {
}
if (!TI->use_empty())
TI->replaceAllUsesWith(UndefValue::get(TI->getType()));
BB->getInstList().erase(TI);
TI->eraseFromParent();
if (&*BB != &F->front())
BlocksToErase.push_back(BB);
else
new UnreachableInst(M.getContext(), BB);
} else {
for (BasicBlock::iterator BI = BB->begin(), E = BB->end(); BI != E; ) {
Instruction *Inst = BI++;
if (Inst->getType()->isVoidTy())
continue;
LatticeVal &IV = Values[Inst];
if (!IV.isConstant() && !IV.isUndefined())
continue;
Constant *Const = IV.isConstant()
? IV.getConstant() : UndefValue::get(Inst->getType());
DEBUG(errs() << " Constant: " << *Const << " = " << *Inst);
// Replaces all of the uses of a variable with uses of the
// constant.
Inst->replaceAllUsesWith(Const);
// Delete the instruction.
if (!isa<CallInst>(Inst) && !isa<TerminatorInst>(Inst))
Inst->eraseFromParent();
// Hey, we just changed something!
MadeChanges = true;
++IPNumInstRemoved;
}
continue;
}
for (BasicBlock::iterator BI = BB->begin(), E = BB->end(); BI != E; ) {
Instruction *Inst = BI++;
if (Inst->getType()->isVoidTy())
continue;
LatticeVal &IV = Values[Inst];
if (!IV.isConstant() && !IV.isUndefined())
continue;
Constant *Const = IV.isConstant()
? IV.getConstant() : UndefValue::get(Inst->getType());
DEBUG(errs() << " Constant: " << *Const << " = " << *Inst);
// Replaces all of the uses of a variable with uses of the
// constant.
Inst->replaceAllUsesWith(Const);
// Delete the instruction.
if (!isa<CallInst>(Inst) && !isa<TerminatorInst>(Inst))
Inst->eraseFromParent();
// Hey, we just changed something!
MadeChanges = true;
++IPNumInstRemoved;
}
}
// Now that all instructions in the function are constant folded, erase dead
// blocks, because we can now use ConstantFoldTerminator to get rid of