1 files changed, 84 insertions, 0 deletions
diff --git a/llvm/tools/llvm-reduce/deltas/RemoveFunctions.cpp b/llvm/tools/llvm-reduce/deltas/RemoveFunctions.cpp
new file mode 100644
index 00000000000..105838f0689
--- /dev/null
+++ b/llvm/tools/llvm-reduce/deltas/RemoveFunctions.cpp
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+//===- llvm-reduce.cpp - The LLVM Delta Reduction utility -----------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a Specialized Delta Pass, which removes the functions that are
+// not in the provided function-chunks.
+//
+//===----------------------------------------------------------------------===//
+
+#include "RemoveFunctions.h"
+
+using namespace llvm;
+
+/// Removes all the Defined Functions (as well as their calls)
+/// that aren't inside any of the desired Chunks.
+/// @returns the Module stripped of out-of-chunk functions
+std::unique_ptr<Module>
+RemoveFunctions::extractChunksFromModule(std::vector<Chunk> ChunksToKeep,
+                                         Module *Program) {
+  std::unique_ptr<Module> Clone = CloneModule(*Program);
+
+  // Get functions inside desired chunks
+  std::set<Function *> FuncsToKeep;
+  int I = 0, FunctionCount = 1;
+  for (auto &F : *Clone) {
+    if (!F.isDeclaration()) {
+      if (FunctionCount >= ChunksToKeep[I].begin &&
+          FunctionCount <= ChunksToKeep[I].end) {
+        FuncsToKeep.insert(&F);
+      }
+      if (FunctionCount >= ChunksToKeep[I].end)
+        ++I;
+      ++FunctionCount;
+    }
+  }
+
+  // Delete out-of-chunk functions, and replace their calls with undef
+  std::vector<Function *> FuncsToRemove;
+  for (auto &F : *Clone) {
+    if (!F.isDeclaration() && !FuncsToKeep.count(&F)) {
+      F.replaceAllUsesWith(UndefValue::get(F.getType()));
+      FuncsToRemove.push_back(&F);
+    }
+  }
+  for (auto *F : FuncsToRemove)
+    F->eraseFromParent();
+
+  // Delete instructions with undef calls
+  std::vector<Instruction *> InstToRemove;
+  for (auto &F : *Clone)
+    for (auto &BB : F)
+      for (auto &I : BB)
+        if (auto *Call = dyn_cast<CallInst>(&I))
+          if (!Call->getCalledFunction()) {
+            // Instruction might be stored / used somewhere else
+            I.replaceAllUsesWith(UndefValue::get(I.getType()));
+            InstToRemove.push_back(&I);
+          }
+
+  for (auto *I : InstToRemove)
+    I->eraseFromParent();
+
+  return Clone;
+}
+
+/// Counts the amount of non-declaration functions and prints their
+/// respective index & name
+int RemoveFunctions::getTargetCount(Module *Program) {
+  // TODO: Silence index with --quiet flag
+  outs() << "----------------------------\n";
+  outs() << "Chunk Index Reference:\n";
+  int FunctionCount = 0;
+  for (auto &F : *Program)
+    if (!F.isDeclaration()) {
+      ++FunctionCount;
+      outs() << "\t" << FunctionCount << ": " << F.getName() << "\n";
+    }
+  outs() << "----------------------------\n";
+  return FunctionCount;
+}