void initializeGCMachineCodeAnalysisPass(PassRegistry&);
void initializeGCModuleInfoPass(PassRegistry&);
void initializeGVNLegacyPassPass(PassRegistry&);
-void initializeGlobalDCEPass(PassRegistry&);
+void initializeGlobalDCELegacyPassPass(PassRegistry&);
void initializeGlobalOptLegacyPassPass(PassRegistry&);
void initializeGlobalsAAWrapperPassPass(PassRegistry&);
void initializeIPCPPass(PassRegistry&);
--- /dev/null
+//===-- GlobalDCE.h - DCE unreachable internal functions ------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This transform is designed to eliminate unreachable internal globals from the
+// program. It uses an aggressive algorithm, searching out globals that are
+// known to be alive. After it finds all of the globals which are needed, it
+// deletes whatever is left over. This allows it to delete recursive chunks of
+// the program which are unreachable.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_IPO_GLOBALDCE_H
+#define LLVM_TRANSFORMS_IPO_GLOBALDCE_H
+
+#include "llvm/IR/Module.h"
+#include "llvm/IR/PassManager.h"
+#include <unordered_map>
+
+namespace llvm {
+
+/// Pass to remove unused function declarations.
+class GlobalDCEPass : public PassInfoMixin<GlobalDCEPass> {
+public:
+ PreservedAnalyses run(Module &M);
+
+private:
+ SmallPtrSet<GlobalValue*, 32> AliveGlobals;
+ SmallPtrSet<Constant *, 8> SeenConstants;
+ std::unordered_multimap<Comdat *, GlobalValue *> ComdatMembers;
+
+ /// Mark the specific global value as needed, and
+ /// recursively mark anything that it uses as also needed.
+ void GlobalIsNeeded(GlobalValue *GV);
+ void MarkUsedGlobalsAsNeeded(Constant *C);
+ bool RemoveUnusedGlobalValue(GlobalValue &GV);
+};
+
+}
+
+#endif // LLVM_TRANSFORMS_IPO_GLOBALDCE_H
initializeInstructionCombiningPassPass(R);
initializeSimpleInlinerPass(R);
initializePruneEHPass(R);
- initializeGlobalDCEPass(R);
+ initializeGlobalDCELegacyPassPass(R);
initializeArgPromotionPass(R);
initializeJumpThreadingPass(R);
initializeSROALegacyPassPass(R);
#include "llvm/Target/TargetMachine.h"
#include "llvm/Transforms/IPO/ForceFunctionAttrs.h"
#include "llvm/Transforms/IPO/FunctionAttrs.h"
+#include "llvm/Transforms/IPO/GlobalDCE.h"
#include "llvm/Transforms/IPO/GlobalOpt.h"
#include "llvm/Transforms/IPO/InferFunctionAttrs.h"
#include "llvm/Transforms/IPO/Internalize.h"
#define MODULE_PASS(NAME, CREATE_PASS)
#endif
MODULE_PASS("forceattrs", ForceFunctionAttrsPass())
+MODULE_PASS("globaldce", GlobalDCEPass())
MODULE_PASS("globalopt", GlobalOptPass())
MODULE_PASS("inferattrs", InferFunctionAttrsPass())
MODULE_PASS("internalize", InternalizePass())
//
//===----------------------------------------------------------------------===//
+#include "llvm/Transforms/IPO/GlobalDCE.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/Constants.h"
STATISTIC(NumVariables, "Number of global variables removed");
namespace {
- struct GlobalDCE : public ModulePass {
+ class GlobalDCELegacyPass : public ModulePass {
+ public:
static char ID; // Pass identification, replacement for typeid
- GlobalDCE() : ModulePass(ID) {
- initializeGlobalDCEPass(*PassRegistry::getPassRegistry());
+ GlobalDCELegacyPass() : ModulePass(ID) {
+ initializeGlobalDCELegacyPassPass(*PassRegistry::getPassRegistry());
}
// run - Do the GlobalDCE pass on the specified module, optionally updating
// the specified callgraph to reflect the changes.
//
- bool runOnModule(Module &M) override;
+ bool runOnModule(Module &M) override {
+ if (skipModule(M))
+ return false;
+
+ auto PA = Impl.run(M);
+ return !PA.areAllPreserved();
+ }
private:
- SmallPtrSet<GlobalValue*, 32> AliveGlobals;
- SmallPtrSet<Constant *, 8> SeenConstants;
- std::unordered_multimap<Comdat *, GlobalValue *> ComdatMembers;
+ GlobalDCEPass Impl;
+ };
+}
- /// GlobalIsNeeded - mark the specific global value as needed, and
- /// recursively mark anything that it uses as also needed.
- void GlobalIsNeeded(GlobalValue *GV);
- void MarkUsedGlobalsAsNeeded(Constant *C);
+char GlobalDCELegacyPass::ID = 0;
+INITIALIZE_PASS(GlobalDCELegacyPass, "globaldce",
+ "Dead Global Elimination", false, false)
- bool RemoveUnusedGlobalValue(GlobalValue &GV);
- };
+// Public interface to the GlobalDCEPass.
+ModulePass *llvm::createGlobalDCEPass() {
+ return new GlobalDCELegacyPass();
}
/// Returns true if F contains only a single "ret" instruction.
return RI.getReturnValue() == nullptr;
}
-char GlobalDCE::ID = 0;
-INITIALIZE_PASS(GlobalDCE, "globaldce",
- "Dead Global Elimination", false, false)
-
-ModulePass *llvm::createGlobalDCEPass() { return new GlobalDCE(); }
-
-bool GlobalDCE::runOnModule(Module &M) {
- if (skipModule(M))
- return false;
-
+PreservedAnalyses GlobalDCEPass::run(Module &M) {
bool Changed = false;
// Remove empty functions from the global ctors list.
SeenConstants.clear();
ComdatMembers.clear();
- return Changed;
+ if (Changed)
+ return PreservedAnalyses::none();
+ return PreservedAnalyses::all();
}
/// GlobalIsNeeded - the specific global value as needed, and
/// recursively mark anything that it uses as also needed.
-void GlobalDCE::GlobalIsNeeded(GlobalValue *G) {
+void GlobalDCEPass::GlobalIsNeeded(GlobalValue *G) {
// If the global is already in the set, no need to reprocess it.
if (!AliveGlobals.insert(G).second)
return;
}
}
-void GlobalDCE::MarkUsedGlobalsAsNeeded(Constant *C) {
+void GlobalDCEPass::MarkUsedGlobalsAsNeeded(Constant *C) {
if (GlobalValue *GV = dyn_cast<GlobalValue>(C))
return GlobalIsNeeded(GV);
// so, nuke it. This will reduce the reference count on the global value, which
// might make it deader.
//
-bool GlobalDCE::RemoveUnusedGlobalValue(GlobalValue &GV) {
+bool GlobalDCEPass::RemoveUnusedGlobalValue(GlobalValue &GV) {
if (GV.use_empty())
return false;
GV.removeDeadConstantUsers();
initializeDAEPass(Registry);
initializeDAHPass(Registry);
initializeForceFunctionAttrsLegacyPassPass(Registry);
- initializeGlobalDCEPass(Registry);
+ initializeGlobalDCELegacyPassPass(Registry);
initializeGlobalOptLegacyPassPass(Registry);
initializeIPCPPass(Registry);
initializeAlwaysInlinerPass(Registry);
-; RUN: opt < %s -globaldce -S | FileCheck %s
+; RUN: opt < %s -passes=globaldce -S | FileCheck %s
; CHECK-NOT: global
@X = external global i32