gcc

This release fixes over 100 reported problems.

This is a bug-fix release containing fixes for regressions and serious bugs, with over 150 bugs fixed since the previous release.

Support for several processor architectures was obsoleted, while new platforms were added. A new general optimization level, -Ofast, was introduced. The Scalable Whole Program Optimizer (WHOPR) project has stabilized to the point of being usable. Many link-time and interprocedural optimization improvements were made. In the C family of languages, support for selectively enabling and disabling warnings was added. The experimental support for C++0x was improved, as well as for the C1X revision of the ISO C standard. Many C++ diagnostics were improved. Many other improvements were made.

The new link-time optimizer LTO ("-flto") is now also supported on several non-ELF targets, namely Cygwin (*-cygwin*), MinGW (*-mingw*), and Darwin on x86-64 (x86_64-apple-darwin*), though LTO is not enabled by default for these targets. Numerous minor bugs were fixed.

Optimizations for Intel Atom processors were added, and the support for other processors was enhanced. The MPC library was integrated for more accurate compile time arithmetic evaluation. A new link-time optimizer was added, to allow for inter-procedural optimizations. Many optimizations were improved. The C compilers now exit immediately on a missing header file. The experimental support for C++0x was improved. An experimental C++ profile mode was added. Many other changes were made.