[ConstraintElimination] Internalize function/class and delete an implied condition. NFC

Delete an implied condition (E.NumIn <= CB.NumIn)
This commit is contained in:
Fangrui Song 2020-09-26 15:04:39 -07:00
parent 6d374cf78c
commit 400bdbc422
1 changed files with 5 additions and 3 deletions

View File

@ -37,7 +37,7 @@ DEBUG_COUNTER(EliminatedCounter, "conds-eliminated",
static int64_t MaxConstraintValue = std::numeric_limits<int64_t>::max();
Optional<std::pair<int64_t, Value *>> decompose(Value *V) {
static Optional<std::pair<int64_t, Value *>> decompose(Value *V) {
if (auto *CI = dyn_cast<ConstantInt>(V)) {
if (CI->isNegative() || CI->uge(MaxConstraintValue))
return {};
@ -116,6 +116,7 @@ getConstraint(CmpInst *Cmp, DenseMap<Value *, unsigned> &Value2Index,
Cmp->getOperand(1), Value2Index, ShouldAdd);
}
namespace {
/// Represents either a condition that holds on entry to a block or a basic
/// block, with their respective Dominator DFS in and out numbers.
struct ConstraintOrBlock {
@ -145,6 +146,7 @@ struct StackEntry {
StackEntry(unsigned NumIn, unsigned NumOut, CmpInst *Condition, bool IsNot)
: NumIn(NumIn), NumOut(NumOut), Condition(Condition), IsNot(IsNot) {}
};
} // namespace
static bool eliminateConstraints(Function &F, DominatorTree &DT) {
bool Changed = false;
@ -192,8 +194,8 @@ static bool eliminateConstraints(Function &F, DominatorTree &DT) {
LLVM_DEBUG(dbgs() << "Top of stack : " << E.NumIn << " " << E.NumOut
<< "\n");
LLVM_DEBUG(dbgs() << "CB: " << CB.NumIn << " " << CB.NumOut << "\n");
bool IsDom = CB.NumIn >= E.NumIn && CB.NumOut <= E.NumOut;
if (IsDom)
assert(E.NumIn <= CB.NumIn);
if (CB.NumOut <= E.NumOut)
break;
LLVM_DEBUG(dbgs() << "Removing " << *E.Condition << " " << E.IsNot
<< "\n");