实在想不出开头就不想了,本期文章咱们来讲讲Clang/GCC的安全编译与代码优化选项。 注意:优化选项建立在代码正确的前提下,且最好不要在使用GDB等工具调试时开启任何优化选项。 LTO(Link-Time Optimization): 中文是链接时优化,最初由LLVM实现,可做到在编译时跨模块执行代码优化,功能有: 函数自动内联 去除无用代码 ...
3. Link Time Optimization (LTO): LTO is a more advanced optimization technique that performs optimizations across multiple object files and libraries. Conclusion. Clang's linking process is a complex and efficient mechanism that ensures the successful combination of object files and libraries into a ...
而在llvm-link阶段,所要做的其实就是把多个.bc文件合并成一个.bc文件,并且做链接时优化,在这篇文章中提到过一个例子:LLVM Link Time Optimization,可以查阅一下是如何进行链接时优化的。 而经过llvm-link阶段后,我们得到了一个新的.bc,那么我们会再次进入优化阶段,重新再进行一次优化。因为经过llvm-link后,我们...
Build the kernel normally, without Link Time Optimization (LTO). config LTO_CLANG_FULL bool "Clang Full LTO (EXPERIMENTAL)" depends on HAS_LTO_CLANG depends on !COMPILE_TEST select LTO_CLANG help This option enables Clang's full Link Time Optimization (LTO), which allows the compiler to opt...
…/kernel/git/kees/linux Pull clang LTO updates from Kees Cook: "Clang Link Time Optimization. This is built on the work done preparing for LTO by arm64 folks, tracing folks, etc. This includes the core changes as well as the remaining pieces for arm64 (LTO has been the default build...
1. LLVM 1.1 LLVM概述 LLVM是架构编译器的框架系统,以C++编写而成,用于优化任意程序语言编写的程序的编译时间(compile-time)、链接时间(link-time)、运行时间(run-time)以及空闲时间(idle-time)。对开发者保持开放,并兼容已有脚本。目前LLVM
Clang 还能提供额外的工具,如控制流分析,link-time optimization, profile-guided optimization。用不同的编译器构建代码也有助于筛选出依赖于未定义行为的代码。Greg Kroah-Hartman 称竞争对每个人都有利,过去五年 GCC 引入的新特性都是与 LLVM/Clang 竞争的结果。他希望 Linux 内核也有竞争对手。
LLVM是架构编译器的框架系统,以C++编写而成,用于优化任意程序语言编写的程序的编译时间(compile-time)、链接时间(link-time)、运行时间(run-time)以及空闲时间(idle-time)。对开发者保持开放,并兼容已有脚本 传统编译器设计 源码Source Code + 前端 Frontend + 优化器 Optimizer + 后端 Backend(代码生成器 CodeGener...
Additionally optimizing across modules with link time optimization (LTO) will give the link-time optimizer (libLTO) better opportunities to reduce code size further. You can quickly enable this feature in µVision'sOptions for Target=>Targettab. The equivalent ARMCLANG command-line option is "-...
对于学习Clang/LLVM来说,其实需要看你做什么,是研究C,C++, Objective-C在Clang的实现,抑或着是想...