The PIC reg (r30) needs to be saved whenever the prologue sets it up,
not just if it is used elsewhere in the function. Without this patch
the prologue for such a function will modify r30 without saving it
first, leading to disaster back in its callers. This happened in the
testsuite for -m32 libgfortran and libstdc++, bootstrapped with -mlra,
many hundred times.
2015-10-29 Segher Boessenkool <segher@kernel.crashing.org>
* config/rs6000/rs6000.c (rs6000_reg_live_or_pic_offset_p): Move this
function earlier in the file.
(first_reg_to_save): Use rs6000_reg_live_or_pic_offset_p instead of
df_regs_ever_live_p.
From-SVN: r229552
