diff options
Diffstat (limited to 'llvm/lib/Transforms/IPO/GlobalOpt.cpp')
-rw-r--r-- | llvm/lib/Transforms/IPO/GlobalOpt.cpp | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp index 5f12825f043..f881e089c26 100644 --- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp +++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp @@ -136,16 +136,16 @@ 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 and -/// constant exprs) as long as they are dead, but it cannot be used by anything -/// else. -static bool ConstantIsDead(Constant *C) { +// SafeToDestroyConstant - It is safe to destroy a constant iff it is only used +// by constants itself. Note that constants cannot be cyclic, so this test is +// pretty easy to implement recursively. +// +static bool SafeToDestroyConstant(Constant *C) { if (isa<GlobalValue>(C)) 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; + if (!SafeToDestroyConstant(CU)) return false; } else return false; return true; @@ -233,7 +233,7 @@ static bool AnalyzeGlobal(Value *V, GlobalStatus &GS, } else if (Constant *C = dyn_cast<Constant>(*UI)) { GS.HasNonInstructionUser = true; // We might have a dead and dangling constant hanging off of here. - if (!ConstantIsDead(C)) + if (!SafeToDestroyConstant(C)) return true; } else { GS.HasNonInstructionUser = true; @@ -338,7 +338,7 @@ 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. - if (ConstantIsDead(C)) { + if (SafeToDestroyConstant(C)) { C->destroyConstant(); // This could have invalidated UI, start over from scratch. CleanupConstantGlobalUsers(V, Init); @@ -354,7 +354,7 @@ static bool CleanupConstantGlobalUsers(Value *V, Constant *Init) { static bool isSafeSROAElementUse(Value *V) { // We might have a dead and dangling constant hanging off of here. if (Constant *C = dyn_cast<Constant>(V)) - return ConstantIsDead(C); + return SafeToDestroyConstant(C); Instruction *I = dyn_cast<Instruction>(V); if (!I) return false; |