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mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 11:13:28 +01:00

Merge duplicated code.

The code for deleting dead global variables and functions was
duplicated.

This is in preparation for also deleting dead global aliases.

llvm-svn: 256274
This commit is contained in:
Rafael Espindola 2015-12-22 19:38:07 +00:00
parent 36fd3caea4
commit 2af3ff098d

View File

@ -55,7 +55,6 @@ STATISTIC(NumSRA , "Number of aggregate globals broken into scalars");
STATISTIC(NumHeapSRA , "Number of heap objects SRA'd");
STATISTIC(NumSubstitute,"Number of globals with initializers stored into them");
STATISTIC(NumDeleted , "Number of globals deleted");
STATISTIC(NumFnDeleted , "Number of functions deleted");
STATISTIC(NumGlobUses , "Number of global uses devirtualized");
STATISTIC(NumLocalized , "Number of globals localized");
STATISTIC(NumShrunkToBool , "Number of global vars shrunk to booleans");
@ -83,6 +82,7 @@ namespace {
bool OptimizeFunctions(Module &M);
bool OptimizeGlobalVars(Module &M);
bool OptimizeGlobalAliases(Module &M);
bool deleteIfDead(GlobalValue &GV);
bool processGlobal(GlobalVariable *GV);
bool processInternalGlobal(GlobalVariable *GV, const GlobalStatus &GS);
bool OptimizeEmptyGlobalCXXDtors(Function *CXAAtExitFn);
@ -1679,20 +1679,37 @@ static bool TryToShrinkGlobalToBoolean(GlobalVariable *GV, Constant *OtherVal) {
return true;
}
bool GlobalOpt::deleteIfDead(GlobalValue &GV) {
GV.removeDeadConstantUsers();
/// Analyze the specified global variable and optimize it if possible. If we
/// make a change, return true.
bool GlobalOpt::processGlobal(GlobalVariable *GV) {
// Do more involved optimizations if the global is internal.
GV->removeDeadConstantUsers();
if (!GV.isDiscardableIfUnused())
return false;
if (GV->use_empty()) {
DEBUG(dbgs() << "GLOBAL DEAD: " << *GV << "\n");
GV->eraseFromParent();
if (const Comdat *C = GV.getComdat())
if (!GV.hasLocalLinkage() && NotDiscardableComdats.count(C))
return false;
bool Dead;
if (auto *F = dyn_cast<Function>(&GV))
Dead = F->isDefTriviallyDead();
else
Dead = GV.use_empty();
if (!Dead)
return false;
DEBUG(dbgs() << "GLOBAL DEAD: " << GV << "\n");
GV.eraseFromParent();
++NumDeleted;
return true;
}
/// Analyze the specified global variable and optimize it if possible. If we
/// make a change, return true.
bool GlobalOpt::processGlobal(GlobalVariable *GV) {
if (deleteIfDead(*GV))
return true;
// Do more involved optimizations if the global is internal.
if (!GV->hasLocalLinkage())
return false;
@ -2023,13 +2040,8 @@ bool GlobalOpt::OptimizeFunctions(Module &M) {
if (!F->hasName() && !F->isDeclaration() && !F->hasLocalLinkage())
F->setLinkage(GlobalValue::InternalLinkage);
const Comdat *C = F->getComdat();
bool inComdat = C && NotDiscardableComdats.count(C);
F->removeDeadConstantUsers();
if ((!inComdat || F->hasLocalLinkage()) && F->isDefTriviallyDead()) {
F->eraseFromParent();
if (deleteIfDead(*F)) {
Changed = true;
++NumFnDeleted;
continue;
}
if (!F->hasLocalLinkage())
@ -2075,13 +2087,8 @@ bool GlobalOpt::OptimizeGlobalVars(Module &M) {
GV->setInitializer(New);
}
if (GV->isDiscardableIfUnused()) {
if (const Comdat *C = GV->getComdat())
if (NotDiscardableComdats.count(C) && !GV->hasLocalLinkage())
continue;
Changed |= processGlobal(GV);
}
}
return Changed;
}