include here:
http://gcc.gnu.org/gcc-4.9/changes.htmlhttp://gcc.gnu.org/gcc-5/changes.html
(note that GCC 5.x is a release stream like GCC 4.9.x, 4.8.x, etc.)
the main issues we will have are:
The default mode for C is now -std=gnu11 instead of -std=gnu89.
ARM:
The deprecated option -mwords-little-endian has been removed.
The options -mapcs, -mapcs-frame, -mtpcs-frame and -mtpcs-leaf-frame
which are only applicable to the old ABI have been deprecated.
MIPS:
The o32 ABI has been modified and extended. The o32 64-bit
floating-point register support is now obsolete and has been removed.
It has been replaced by three ABI extensions FPXX, FP64A, and FP64.
The meaning of the -mfp64 command-line option has changed. It is now
used to enable the FP64A and FP64 ABI extensions.
mrg