The PPC64LE ABI specifies POWER8 ISA as the minimum hardware
requierment. Currently, Linux distributions are building the
toolchain using --with-cpu=power7 or power8, as they wish. GCC
defaults to essentially the POWER4 ISA.
The appended patch changes the default for PPC64LE to POWER8 (ISA
2.7). 32-bit PPC SVR4 is not really defined, but it is left unchanged
with no minimum ISA.
The default ISA can be overridden using --with-cpu= and we presume
that Linux distributions and users will continue to configure as they
require for their deployment.
* config/rs6000/default64.h (TARGET_DEFAULT) [LITTLE_ENDIAN]: Use ISA
2.7 (POWER8).