GCC 7.1 is a major release containing substantial new functionality not available in GCC 6.x or previous GCC releases.
The C++ frontend now has experimental support for all of the current C++17 draft, with the
-std=gnu++1zoptions, and the
libstdc++library has most of the C++17 draft library features implemented too.
This release features various improvements in the emitted diagnostics, including improved locations, location ranges, suggestions for misspelled identifiers, option names, fix-it hints and various new warnings have been added.
The optimizers have been improved, with improvements appearing in all of intra- and inter-procedural optimizations, link time optimizations and various target backends, including, but not limited to, additions of store merging pass, code hoisting optimization, loop splitting, and shrink wrapping improvements.
— From a GCC Announce Newsletter