Release Notes: 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.
Release Notes: C++11 ref-qualifiers were implemented. The C++11 <chrono> std::chrono::system_clock and std::chrono::steady_clock classes were changed. Various minor bugs were fixed.
Release Notes: GCC is now implemented in C++. DWARF4 is now the default when generating DWARF debug information (tool support required). A new general optimization level "-Og" was introduced. AddressSanitizer, a fast memory error detector, was added. ThreadSanitizer was added (x86-64 only) for instrumenting instructions to detect data races. C++11 was enhanced with support for the thread_local keyword, for attribute syntax, for the alignment specifier, and for inheriting constructors. Support for AArch64 as well as ARMv8 AArch32 extensions was added. Various other improvements and bugfixes were made.
Release Notes: This major release contains substantial new functionality not available in GCC 4.6.x or previous GCC releases.
Release Notes: This release fixes over 100 reported problems.
Release Notes: This is a bug-fix release containing fixes for regressions and serious bugs, with over 150 bugs fixed since the previous release.