================ @@ -0,0 +1,215 @@ +//===--- ProfileFuncRef.h - Sample profile function reference ---*- C++ -*-===// +// +// 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 +// +//===----------------------------------------------------------------------===// +/// +/// \file +/// +/// Defines ProfileFuncRef class. +/// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_PROFILEDATA_PROFILEFUNCREF_H +#define LLVM_PROFILEDATA_PROFILEFUNCREF_H + +#include "llvm/ADT/DenseMapInfo.h" +#include "llvm/ADT/Hashing.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/Support/MD5.h" +#include "llvm/Support/raw_ostream.h" +#include <cstdint> + +namespace llvm { +namespace sampleprof { + +/// This class represents a function that is read from a sample profile. It +/// comes with two forms: a string or a hash code. The latter form is the 64-bit +/// MD5 of the function name for efficient storage supported by ExtBinary +/// profile format, and when reading the profile, this class can represent it +/// without converting it to a string first. +/// When representing a hash code, we utilize the LengthOrHashCode field to +/// store it, and Name is set to null. When representing a string, it is same as +/// StringRef. +class ProfileFuncRef { + + const char *Data = nullptr; + + /// Use uint64_t instead of size_t so that it can also hold a MD5 value. + uint64_t LengthOrHashCode = 0; + + /// Extension to memcmp to handle hash code representation. If both are hash + /// values, Lhs and Rhs are both null, function returns 0 (and needs an extra + /// comparison using getIntValue). If only one is hash code, it is considered + /// less than the StringRef one. Otherwise perform normal string comparison. + static int compareMemory(const char *Lhs, const char *Rhs, uint64_t Length) { + if (Lhs == Rhs) + return 0; + if (!Lhs) + return -1; + if (!Rhs) + return 1; + return ::memcmp(Lhs, Rhs, (size_t)Length); + } + +public: + ProfileFuncRef() = default; + + /// Constructor from a StringRef. + explicit ProfileFuncRef(StringRef Str) + : Data(Str.data()), LengthOrHashCode(Str.size()) { + if (!Str.getAsInteger(10, LengthOrHashCode)) + Data = nullptr; ---------------- MatzeB wrote:
Could we keep the constructor simple and just initialize the `ProfileFuncRef` with a string and keep the "try parsing as an integer" logic to outside callers like need it? This also seems to rely on function names not being a string of digits, which is not true on the object file level (so maybe some language or language feature I am not aware of my produce such names). I can also create such functions with the asm label extension: ``` $ cat x.cpp void james_bond() __asm__("007"); void james_bond() {} $ clang++ -S -o - -emit-llvm x.cpp ... define dso_local void @"007"() #0 { ... ``` https://github.com/llvm/llvm-project/pull/66164 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits