Revert rev. 66167.

We are still not out of woods yet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66232 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Devang Patel 2009-03-06 01:37:41 +00:00
parent 5c6bf65a09
commit 743cdf8edf
2 changed files with 10 additions and 31 deletions

View File

@ -138,28 +138,17 @@ struct VISIBILITY_HIDDEN GlobalStatus {
}
/// ConstantIsDead - Return true if the specified constant is (transitively)
/// dead. The constant may be used by other constants (e.g. constant arrays,
/// constant exprs, constant global variables) as long as they are dead,
/// but it cannot be used by anything else. If DeadGVs is not null then
/// record dead constant GV users.
static bool ConstantIsDead(Constant *C,
SmallPtrSet<GlobalVariable *, 4> *DeadGVs = false) {
/// dead. The constant may be used by other constants (e.g. constant arrays and
/// constant exprs) as long as they are dead, but it cannot be used by anything
/// else.
static bool ConstantIsDead(Constant *C) {
if (isa<GlobalValue>(C)) return false;
for (Value::use_iterator UI = C->use_begin(), E = C->use_end(); UI != E; ++UI) {
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(*UI)) {
if (!GV->isConstant() || !GV->hasLocalLinkage() || !GV->use_empty())
return false;
else {
if (DeadGVs)
DeadGVs->insert(GV);
}
}
else if (Constant *CU = dyn_cast<Constant>(*UI)) {
if (!ConstantIsDead(CU, DeadGVs)) return false;
for (Value::use_iterator UI = C->use_begin(), E = C->use_end(); UI != E; ++UI)
if (Constant *CU = dyn_cast<Constant>(*UI)) {
if (!ConstantIsDead(CU)) return false;
} else
return false;
}
return true;
}
@ -350,19 +339,8 @@ static bool CleanupConstantGlobalUsers(Value *V, Constant *Init) {
} else if (Constant *C = dyn_cast<Constant>(U)) {
// If we have a chain of dead constantexprs or other things dangling from
// us, and if they are all dead, nuke them without remorse.
SmallPtrSet<GlobalVariable *, 4> DeadGVs;
if (ConstantIsDead(C, &DeadGVs)) {
for (SmallPtrSet<GlobalVariable *, 4>::iterator TI = DeadGVs.begin(),
TE = DeadGVs.end(); TI != TE; ) {
GlobalVariable *TGV = *TI; ++TI;
if (TGV == C)
C = NULL;
TGV->eraseFromParent();
}
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
GV->eraseFromParent();
else if (C)
C->destroyConstant();
if (ConstantIsDead(C)) {
C->destroyConstant();
// This could have invalidated UI, start over from scratch.
CleanupConstantGlobalUsers(V, Init);
return true;

View File

@ -1,4 +1,5 @@
; RUN: llvm-as < %s | opt -globalopt | llvm-dis | not grep global_variable42
; XFAIL: *
%llvm.dbg.anchor.type = type { i32, i32 }
%llvm.dbg.basictype.type = type { i32, { }*, i8*, { }*, i32, i64, i64, i64, i32, i32 }