Add module clone pass.

llvm/include/llvm/InitializePasses.h

@@ -344,6 +344,7 @@ void initializeXRayInstrumentationPass(PassRegistry&);
 void initializeYkStackmapsPass(PassRegistry&);
 void initializeYkSplitBlocksAfterCallsPass(PassRegistry&);
 void initializeYkBasicBlockTracerPass(PassRegistry&);
+void initializeYkModuleClonePass(PassRegistry&);
 } // end namespace llvm
 
 #endif // LLVM_INITIALIZEPASSES_H

llvm/include/llvm/Transforms/Yk/ModuleClone.h

@@ -0,0 +1,10 @@
+#ifndef LLVM_TRANSFORMS_YK_MODULE_CLONE_H
+#define LLVM_TRANSFORMS_YK_MODULE_CLONE_H
+
+#include "llvm/Pass.h"
+
+namespace llvm {
+ModulePass *createYkModuleClonePass();
+} // namespace llvm
+
+#endif

llvm/lib/CodeGen/CodeGen.cpp

@@ -153,4 +153,5 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeYkStackmapsPass(Registry);
   initializeYkSplitBlocksAfterCallsPass(Registry);
   initializeYkBasicBlockTracerPass(Registry);
+  initializeYkModuleClonePass(Registry);
 }

llvm/lib/CodeGen/TargetPassConfig.cpp

@@ -56,6 +56,7 @@
 #include "llvm/Transforms/Yk/Stackmaps.h"
 #include "llvm/Transforms/Yk/NoCallsInEntryBlocks.h"
 #include "llvm/Transforms/Yk/BasicBlockTracer.h"
+#include "llvm/Transforms/Yk/ModuleClone.h"
 #include <cassert>
 #include <optional>
 #include <string>
@@ -297,6 +298,9 @@ static cl::opt<bool>
     YkBasicBlockTracer("yk-basicblock-tracer", cl::init(false), cl::NotHidden,
                       cl::desc("Enables YK Software Tracer capability"));
 
+static cl::opt<bool>
+    YkModuleClone("yk-module-clone", cl::init(false), cl::NotHidden,
+                  cl::desc("Enables YK Module Cloning capability"));
 
 /// Allow standard passes to be disabled by command line options. This supports
 /// simple binary flags that either suppress the pass or do nothing.
@@ -1190,6 +1194,9 @@ bool TargetPassConfig::addISelPasses() {
   if (YkBasicBlockTracer) {
     addPass(createYkBasicBlockTracerPass());
   }
+  if (YkModuleClone){
+    addPass(createYkModuleClonePass());
+  }
 
   addISelPrepare();
   return addCoreISelPasses();

llvm/lib/Transforms/Yk/CMakeLists.txt

@@ -8,6 +8,7 @@ add_llvm_component_library(LLVMYkPasses
   NoCallsInEntryBlocks.cpp
   SplitBlocksAfterCalls.cpp
   BasicBlockTracer.cpp
+  ModuleClone.cpp
 
   DEPENDS
   intrinsics_gen
@@ -16,4 +17,6 @@ add_llvm_component_library(LLVMYkPasses
   Analysis
   Core
   Support
+  TransformUtils # Module Clone
+  Linker         # Module Linker
 )

llvm/lib/Transforms/Yk/ModuleClone.cpp

@@ -0,0 +1,78 @@
+#include "llvm/Transforms/Yk/ModuleClone.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/InitializePasses.h"
+#include "llvm/Linker/Linker.h"
+#include "llvm/Pass.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+
+#define DEBUG_TYPE "yk-module-clone-pass"
+
+using namespace llvm;
+
+namespace llvm {
+void initializeYkModuleClonePass(PassRegistry &);
+} // namespace llvm
+
+namespace {
+struct YkModuleClone : public ModulePass {
+  static char ID;
+  const std::string ClonePrefix = "__yk_clone_";
+
+  YkModuleClone() : ModulePass(ID) {
+    initializeYkModuleClonePass(*PassRegistry::getPassRegistry());
+  }
+
+  void updateClonedFunctions(Module &M) {
+    for (llvm::Function &F : M) {
+      if (F.hasExternalLinkage() && F.isDeclaration()) {
+        continue;
+      }
+      F.setName(ClonePrefix + F.getName().str());
+    }
+  }
+
+  void updateClonedGlobals(Module &M) {
+    for (llvm::GlobalVariable &GV : M.globals()) {
+      std::string GlobalName = GV.getName().str();
+      if (GlobalName.find('.') == 0) {
+        continue; // This is likely not user-defined. Example: `.L.str`.
+      }
+      GV.setInitializer(nullptr); // Remove the initializer
+      GV.setLinkage(llvm::GlobalValue::ExternalLinkage); // Set external linkage
+    }
+  }
+
+  bool runOnModule(Module &M) override {
+    if (M.getName() == "src/perf/collect.c") {
+      return false;
+    }
+    std::unique_ptr<Module> Cloned = CloneModule(M);
+    if (!Cloned) {
+      errs() << "Error: CloneModule returned null for module: " << M.getName()
+             << "\n";
+      return false;
+    }
+    updateClonedFunctions(*Cloned);
+    updateClonedGlobals(*Cloned);
+
+    llvm::Linker TheLinker(M);
+    if (TheLinker.linkInModule(std::move(Cloned))) {
+      llvm::report_fatal_error("Error linking the modules");
+      return false;
+    }
+    return true;
+  }
+};
+} // namespace
+
+char YkModuleClone::ID = 0;
+
+INITIALIZE_PASS(YkModuleClone, DEBUG_TYPE, "yk module clone", false, false)
+
+ModulePass *llvm::createYkModuleClonePass() { return new YkModuleClone(); }

llvm/lib/YkIR/CMakeLists.txt

@@ -5,4 +5,6 @@ add_llvm_component_library(LLVMYkIR
   Core
   MC
   Support
+  TransformUtils
+  Linker
   )