Tag Archive for Visual Studio 2015

Performance Improvements with Visual Studio 2015 Update 2

Visual Studio 2015 Update 2, released on March 30 2016, brought a couple of performance improvements.

  • Enabled a new database engine; now, C++ Project load should be faster and experience fewer UI delays.
  • Increased the speed of extracting floating-point numbers with iostreams (in other words, “stream >> dbl”). It’s now up to 19x faster, and all bits of the extracted value are now correct.
  • Increased the speed of std::vector reallocation and std::copy(); they are up to 9x faster as they call memmove() for trivially copyable types (including user-defined types).
  • Increased the speed of std::vector, which is up to 11x faster.
  • Increased the speed of std::string::replace(), which is enormously faster when replacing same-size substrings.
  • Increased the speed of std::string::push_back(), which is up to 3x faster.
  • Increased the speed of std::sub_match comparisons, as they now avoid constructing temporary std::strings.
  • Increased the speed of std::function’s copy constructor; it is slightly faster with a reduced codegen size.

The full official release notes can be found here.


Visual Studio 2015 Preview

Microsoft has released a preview of Visual Studio 2015.
There are a lot of C++ changes included in this preview. You can read the full release notes here.

Here is a short version quoted from a blog post from Eric Battalio from Microsoft:

  • C++ Cross-Platform Mobile Development. C++ is attractive because it offers portability and a chance to reuse the same code on different platforms. With Visual Studio 2015 Preview, modern application developers can use the Visual C++ tool chain (c1xx, c2) to target Microsoft Windows Platforms and Clang / LLVM for targeting Android (with plans to support iOS in the near future). This makes it even easier to re-use existing C++ libraries to target multiple platforms (Android/Windows/iOS), share cross-platform code, and create high-quality Xamarin Native Android and Native-Activity applications using all of the power of Visual Studio. For a closer look, see Cross-Platform Mobile Development with Visual C++.
  • C++11, C++14, C++17 (proposed) compatibility. Standards support across compilers improves portability. With Visual Studio 2015 Preview, Visual C++ is even more compliant with user-defined literals (C++11), generic lambdas (C++14), and await (C++17 proposed). For a view of VS conformance in table form, see this post by Stephan Lavavej (STL). Also check out Details About Some of the New C++ Language Features, Improvements to Warnings in the C++ Compiler, and Resumable Functions in C++.
  • Enhanced productivity & build-time improvements. “Productivity” and “C++” are not often used in the same sentence except to criticize some aspect of the IDE, build process or diagnostics. Friction in any of these areas slows down the development process. With Visual Studio 2015 Preview, you get improvements in each including refactoring for C++ and improved IntelliSense database buildup and simplified QuickInfo for template deduction (IDE); incremental linking for static libs, new fast PDB generation techniques, multithreading in the linker (build); and dedicated space for analyzing graphics space using the Visual Studio Graphics Analyzer (VSGA) and you can view the impact of shader code changes without re-running the app (diagnostics). For more details about incremental build, see Speeding up the Incremental Build Scenario.
  • Improved performance. Most of the C++ developers we spoke with needed code to run fast, often as part of intensive data transformation or analysis or real-time control. Visual Studio 2015 Preview builds on the AVX2 support in Visual Studio 2013 to bring more general optimizations like loop-if unswitching, Vectorization of control flow, and increased support for Vectorization (including when optimizing in favor of smaller code). In addition we have a number of ARM32 compiler code generation improvements.

See Eric’s blog post here for a couple more links.
Download the Visual Studio 2015 Preview.