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-rw-r--r--llvm/lib/Transforms/IPO/GlobalOpt.cpp137
1 files changed, 71 insertions, 66 deletions
diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
index 558e9774367..dbace87b2c3 100644
--- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -76,21 +76,6 @@ namespace {
}
bool runOnModule(Module &M) override;
-
- private:
- bool OptimizeFunctions(Module &M);
- bool OptimizeGlobalVars(Module &M);
- bool OptimizeGlobalAliases(Module &M);
- bool deleteIfDead(GlobalValue &GV);
- bool processGlobal(GlobalValue &GV);
- bool processInternalGlobal(GlobalVariable *GV, const GlobalStatus &GS);
- bool OptimizeEmptyGlobalCXXDtors(Function *CXAAtExitFn);
-
- bool isPointerValueDeadOnEntryToFunction(const Function *F,
- GlobalValue *GV);
-
- TargetLibraryInfo *TLI;
- SmallSet<const Comdat *, 8> NotDiscardableComdats;
};
}
@@ -1681,7 +1666,8 @@ static bool TryToShrinkGlobalToBoolean(GlobalVariable *GV, Constant *OtherVal) {
return true;
}
-bool GlobalOpt::deleteIfDead(GlobalValue &GV) {
+static bool deleteIfDead(GlobalValue &GV,
+ SmallSet<const Comdat *, 8> &NotDiscardableComdats) {
GV.removeDeadConstantUsers();
if (!GV.isDiscardableIfUnused())
@@ -1705,36 +1691,9 @@ bool GlobalOpt::deleteIfDead(GlobalValue &GV) {
return true;
}
-/// Analyze the specified global variable and optimize it if possible. If we
-/// make a change, return true.
-bool GlobalOpt::processGlobal(GlobalValue &GV) {
- // Do more involved optimizations if the global is internal.
- if (!GV.hasLocalLinkage())
- return false;
-
- GlobalStatus GS;
-
- if (GlobalStatus::analyzeGlobal(&GV, GS))
- return false;
-
- bool Changed = false;
- if (!GS.IsCompared && !GV.hasUnnamedAddr()) {
- GV.setUnnamedAddr(true);
- NumUnnamed++;
- Changed = true;
- }
-
- auto *GVar = dyn_cast<GlobalVariable>(&GV);
- if (!GVar)
- return Changed;
-
- if (GVar->isConstant() || !GVar->hasInitializer())
- return Changed;
-
- return processInternalGlobal(GVar, GS) || Changed;
-}
-
-bool GlobalOpt::isPointerValueDeadOnEntryToFunction(const Function *F, GlobalValue *GV) {
+static bool isPointerValueDeadOnEntryToFunction(
+ const Function *F, GlobalValue *GV,
+ function_ref<DominatorTree &(Function &)> LookupDomTree) {
// Find all uses of GV. We expect them all to be in F, and if we can't
// identify any of the uses we bail out.
//
@@ -1778,8 +1737,7 @@ bool GlobalOpt::isPointerValueDeadOnEntryToFunction(const Function *F, GlobalVal
// of them are known not to depend on the value of the global at the function
// entry point. We do this by ensuring that every load is dominated by at
// least one store.
- auto &DT = getAnalysis<DominatorTreeWrapperPass>(*const_cast<Function *>(F))
- .getDomTree();
+ auto &DT = LookupDomTree(*const_cast<Function *>(F));
// The below check is quadratic. Check we're not going to do too many tests.
// FIXME: Even though this will always have worst-case quadratic time, we
@@ -1868,8 +1826,9 @@ static void makeAllConstantUsesInstructions(Constant *C) {
/// Analyze the specified global variable and optimize
/// it if possible. If we make a change, return true.
-bool GlobalOpt::processInternalGlobal(GlobalVariable *GV,
- const GlobalStatus &GS) {
+static bool processInternalGlobal(
+ GlobalVariable *GV, const GlobalStatus &GS, TargetLibraryInfo *TLI,
+ function_ref<DominatorTree &(Function &)> LookupDomTree) {
auto &DL = GV->getParent()->getDataLayout();
// If this is a first class global and has only one accessing function and
// this function is non-recursive, we replace the global with a local alloca
@@ -1886,7 +1845,8 @@ bool GlobalOpt::processInternalGlobal(GlobalVariable *GV,
!GV->isExternallyInitialized() &&
allNonInstructionUsersCanBeMadeInstructions(GV) &&
GS.AccessingFunction->doesNotRecurse() &&
- isPointerValueDeadOnEntryToFunction(GS.AccessingFunction, GV) ) {
+ isPointerValueDeadOnEntryToFunction(GS.AccessingFunction, GV,
+ LookupDomTree)) {
DEBUG(dbgs() << "LOCALIZING GLOBAL: " << *GV << "\n");
Instruction &FirstI = const_cast<Instruction&>(*GS.AccessingFunction
->getEntryBlock().begin());
@@ -1898,7 +1858,7 @@ bool GlobalOpt::processInternalGlobal(GlobalVariable *GV,
new StoreInst(GV->getInitializer(), Alloca, &FirstI);
makeAllConstantUsesInstructions(GV);
-
+
GV->replaceAllUsesWith(Alloca);
GV->eraseFromParent();
++NumLocalized;
@@ -1996,6 +1956,37 @@ bool GlobalOpt::processInternalGlobal(GlobalVariable *GV,
return false;
}
+/// Analyze the specified global variable and optimize it if possible. If we
+/// make a change, return true.
+static bool
+processGlobal(GlobalValue &GV, TargetLibraryInfo *TLI,
+ function_ref<DominatorTree &(Function &)> LookupDomTree) {
+ // Do more involved optimizations if the global is internal.
+ if (!GV.hasLocalLinkage())
+ return false;
+
+ GlobalStatus GS;
+
+ if (GlobalStatus::analyzeGlobal(&GV, GS))
+ return false;
+
+ bool Changed = false;
+ if (!GS.IsCompared && !GV.hasUnnamedAddr()) {
+ GV.setUnnamedAddr(true);
+ NumUnnamed++;
+ Changed = true;
+ }
+
+ auto *GVar = dyn_cast<GlobalVariable>(&GV);
+ if (!GVar)
+ return Changed;
+
+ if (GVar->isConstant() || !GVar->hasInitializer())
+ return Changed;
+
+ return processInternalGlobal(GVar, GS, TLI, LookupDomTree) || Changed;
+}
+
/// Walk all of the direct calls of the specified function, changing them to
/// FastCC.
static void ChangeCalleesToFastCall(Function *F) {
@@ -2040,7 +2031,10 @@ static bool isProfitableToMakeFastCC(Function *F) {
return CC == CallingConv::C || CC == CallingConv::X86_ThisCall;
}
-bool GlobalOpt::OptimizeFunctions(Module &M) {
+static bool
+OptimizeFunctions(Module &M, TargetLibraryInfo *TLI,
+ function_ref<DominatorTree &(Function &)> LookupDomTree,
+ SmallSet<const Comdat *, 8> &NotDiscardableComdats) {
bool Changed = false;
// Optimize functions.
for (Module::iterator FI = M.begin(), E = M.end(); FI != E; ) {
@@ -2049,12 +2043,12 @@ bool GlobalOpt::OptimizeFunctions(Module &M) {
if (!F->hasName() && !F->isDeclaration() && !F->hasLocalLinkage())
F->setLinkage(GlobalValue::InternalLinkage);
- if (deleteIfDead(*F)) {
+ if (deleteIfDead(*F, NotDiscardableComdats)) {
Changed = true;
continue;
}
- Changed |= processGlobal(*F);
+ Changed |= processGlobal(*F, TLI, LookupDomTree);
if (!F->hasLocalLinkage())
continue;
@@ -2081,7 +2075,10 @@ bool GlobalOpt::OptimizeFunctions(Module &M) {
return Changed;
}
-bool GlobalOpt::OptimizeGlobalVars(Module &M) {
+static bool
+OptimizeGlobalVars(Module &M, TargetLibraryInfo *TLI,
+ function_ref<DominatorTree &(Function &)> LookupDomTree,
+ SmallSet<const Comdat *, 8> &NotDiscardableComdats) {
bool Changed = false;
for (Module::global_iterator GVI = M.global_begin(), E = M.global_end();
@@ -2099,12 +2096,12 @@ bool GlobalOpt::OptimizeGlobalVars(Module &M) {
GV->setInitializer(New);
}
- if (deleteIfDead(*GV)) {
+ if (deleteIfDead(*GV, NotDiscardableComdats)) {
Changed = true;
continue;
}
- Changed |= processGlobal(*GV);
+ Changed |= processGlobal(*GV, TLI, LookupDomTree);
}
return Changed;
}
@@ -2175,7 +2172,7 @@ static void CommitValueTo(Constant *Val, Constant *Addr) {
/// Evaluate static constructors in the function, if we can. Return true if we
/// can, false otherwise.
static bool EvaluateStaticConstructor(Function *F, const DataLayout &DL,
- const TargetLibraryInfo *TLI) {
+ TargetLibraryInfo *TLI) {
// Call the function.
Evaluator Eval(DL, TLI);
Constant *RetValDummy;
@@ -2347,7 +2344,9 @@ static bool hasUsesToReplace(GlobalAlias &GA, const LLVMUsed &U,
return true;
}
-bool GlobalOpt::OptimizeGlobalAliases(Module &M) {
+static bool
+OptimizeGlobalAliases(Module &M,
+ SmallSet<const Comdat *, 8> &NotDiscardableComdats) {
bool Changed = false;
LLVMUsed Used(M);
@@ -2362,7 +2361,7 @@ bool GlobalOpt::OptimizeGlobalAliases(Module &M) {
if (!J->hasName() && !J->isDeclaration() && !J->hasLocalLinkage())
J->setLinkage(GlobalValue::InternalLinkage);
- if (deleteIfDead(*J)) {
+ if (deleteIfDead(*J, NotDiscardableComdats)) {
Changed = true;
continue;
}
@@ -2484,7 +2483,7 @@ static bool cxxDtorIsEmpty(const Function &Fn,
return false;
}
-bool GlobalOpt::OptimizeEmptyGlobalCXXDtors(Function *CXAAtExitFn) {
+static bool OptimizeEmptyGlobalCXXDtors(Function *CXAAtExitFn) {
/// Itanium C++ ABI p3.3.5:
///
/// After constructing a global (or local static) object, that will require
@@ -2538,8 +2537,12 @@ bool GlobalOpt::runOnModule(Module &M) {
bool Changed = false;
auto &DL = M.getDataLayout();
- TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
+ auto *TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
+ auto LookupDomTree = [this](Function &F) -> DominatorTree & {
+ return this->getAnalysis<DominatorTreeWrapperPass>(F).getDomTree();
+ };
+ SmallSet<const Comdat *, 8> NotDiscardableComdats;
bool LocalChange = true;
while (LocalChange) {
LocalChange = false;
@@ -2559,7 +2562,8 @@ bool GlobalOpt::runOnModule(Module &M) {
NotDiscardableComdats.insert(C);
// Delete functions that are trivially dead, ccc -> fastcc
- LocalChange |= OptimizeFunctions(M);
+ LocalChange |=
+ OptimizeFunctions(M, TLI, LookupDomTree, NotDiscardableComdats);
// Optimize global_ctors list.
LocalChange |= optimizeGlobalCtorsList(M, [&](Function *F) {
@@ -2567,10 +2571,11 @@ bool GlobalOpt::runOnModule(Module &M) {
});
// Optimize non-address-taken globals.
- LocalChange |= OptimizeGlobalVars(M);
+ LocalChange |= OptimizeGlobalVars(M, TLI, LookupDomTree,
+ NotDiscardableComdats);
// Resolve aliases, when possible.
- LocalChange |= OptimizeGlobalAliases(M);
+ LocalChange |= OptimizeGlobalAliases(M, NotDiscardableComdats);
// Try to remove trivial global destructors if they are not removed
// already.
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