Link Time Optimization

Link Time Optimization (LTO) gives GCC the capability of dumping its internal representation (GIMPLE) to disk, so that all the different compilation units that make up a single executable can be optimized as a single module. This expands the scope of inter-procedural optimizations to encompass the whole program (or, rather, everything that is visible at link time).

• Design Overview
  • LTO modes of operation
• LTO file sections
• Using summary information in IPA passes
  • Virtual clones
  • IPA references
  • Jump functions
• Whole program assumptions, linker plugin and symbol visibilities
• Internal flags controlling lto1