hoist GlobalValue::removeDeadConstantUsers up to being a method on Constant.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125828 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
2011-02-18 04:41:42 +00:00
parent f5ebfb0d28
commit 13fb0db0c2
4 changed files with 62 additions and 58 deletions

View File

@@ -26,23 +26,6 @@ using namespace llvm;
// GlobalValue Class
//===----------------------------------------------------------------------===//
/// removeDeadUsersOfConstant - If the specified constantexpr is dead, remove
/// it. This involves recursively eliminating any dead users of the
/// constantexpr.
static bool removeDeadUsersOfConstant(const Constant *C) {
if (isa<GlobalValue>(C)) return false; // Cannot remove this
while (!C->use_empty()) {
const Constant *User = dyn_cast<Constant>(C->use_back());
if (!User) return false; // Non-constant usage;
if (!removeDeadUsersOfConstant(User))
return false; // Constant wasn't dead
}
const_cast<Constant*>(C)->destroyConstant();
return true;
}
bool GlobalValue::isMaterializable() const {
return getParent() && getParent()->isMaterializable(this);
}
@@ -56,38 +39,6 @@ void GlobalValue::Dematerialize() {
getParent()->Dematerialize(this);
}
/// removeDeadConstantUsers - If there are any dead constant users dangling
/// off of this global value, remove them. This method is useful for clients
/// that want to check to see if a global is unused, but don't want to deal
/// with potentially dead constants hanging off of the globals.
void GlobalValue::removeDeadConstantUsers() const {
Value::const_use_iterator I = use_begin(), E = use_end();
Value::const_use_iterator LastNonDeadUser = E;
while (I != E) {
if (const Constant *User = dyn_cast<Constant>(*I)) {
if (!removeDeadUsersOfConstant(User)) {
// If the constant wasn't dead, remember that this was the last live use
// and move on to the next constant.
LastNonDeadUser = I;
++I;
} else {
// If the constant was dead, then the iterator is invalidated.
if (LastNonDeadUser == E) {
I = use_begin();
if (I == E) break;
} else {
I = LastNonDeadUser;
++I;
}
}
} else {
LastNonDeadUser = I;
++I;
}
}
}
/// Override destroyConstant to make sure it doesn't get called on
/// GlobalValue's because they shouldn't be treated like other constants.
void GlobalValue::destroyConstant() {