[Patch 2/3] aarch64: Introduce SLS mitigation for RET and BR instructions

[Matthew Malcomson]

On 23/06/2020 17:17, Richard Sandiford wrote:
> Matthew Malcomson <matthew.malcomson@arm.com> writes:
>> --- a/gcc/config/aarch64/aarch64-protos.h
>> +/* Ensure there are no BR or RET instructions which are not directly followed
>> +   by a speculation barrier.  */
>> +/* { dg-final { scan-assembler-not "\t(br|ret|retaa|retab)\tx\[0-9\]\[0-9\]?\n\t(?!dsb\tsy\n\tisb|sb)" } } */
> 
> Isn't the “sb” alternative invalid given the -march option?
> 
> Probably slightly easier to read if the regexp is quoted using {…}
> rather than "…".  Same for the other tests.
> 

Just to check before I respin:  Using {} instead of "" means I need to 
replace \t with a literal tab -- do you still prefer it?