[llvm] [CopyProf] Add CopyProf instrumentation passes. (PR #207385)

[via llvm-commits]

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+//===-- CopyProf.cpp ------------------------------------------------------===//
+//
+// 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 implements the LLVM IR instrumentation passes for CopyProf.
+/// It adds enter/exit callbacks to C++ special member functions, and
+/// instruments store instructions.
+///
+/// The basic idea of the CopyProf algorithm works like this:
+/// An object copy Y is made from original object X. The shadow memory
+/// corresponding to (and owned by) Y is marked as "copied". Any subsequent
+/// memory store to the memory corresponding to Y marks the shadow memory as
+/// "modified". When Y is destroyed and all of its corresponding shadow memory
+/// is marked as "copied", the object is reported as an unnecessary copy.
+///
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Instrumentation/CopyProf.h"
+
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FormatVariadic.h"
+#include "llvm/Transforms/Utils/Instrumentation.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
+#include <array>
+#include <cstddef>
+#include <cstdint>
+
+// TODO: Convert CopyProfPass and CopyProfStoresPass to module passes so that
+// the runtime callbacks can be cached, thus avoiding repetitive symbol table
+// lookups.
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newgre wrote:

`CopyProfPass` as well as `CopyProfStoresPass` are function passes. `ModuleCopyProfPass` is the only module pass.

https://github.com/llvm/llvm-project/pull/207385