PowerPC64 power8 strncpy cfi fixes

[Tulio Magno Quites Machado Filho]

Alan Modra <amodra@gmail.com> writes:

> cfi info for stack adjust needs to be on the insn doing the adjust.
> cfi describing register saves can be anywhere after the save insn but
> before the reg is altered.  Fewer locations with cfi result in smaller
> cfi programs and possibly slightly faster exception handling.  Thus
> the LR cfi_offset move.
>
> The idea behind ajusting sp after restoring regs is to break a
> register dependency chain, in this case not be using r1 immediately
> after it is modified.
>
> The missing LR cfi_restore meant that code after the blr,
> unaligned_lt_16 and other labels, would have cfi that said LR was at
> cfa+16, but that code is reached without LR being saved.
>
> 	* sysdeps/powerpc/powerpc64/power8/strncpy.S: Move LR cfi.
> 	Adjust stack after restoring regs.  Add missing LR cfi_restore.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com>

-- 
Tulio Magno