Re: [PATCH v2 0/5] Add support for AArch64 MOPS instructions

[Luis Machado <luis.machado@arm.com>]

On 5/10/24 06:20, Thiago Jung Bauermann wrote:
> Thiago Jung Bauermann <thiago.bauermann@linaro.org> writes:
> 
>> Maybe one thing that GDB would need to handle is when the user requests
>> a breakpoint in the main or epilogue instruction of the sequence. In
>> that case I think GDB would have to put the trap instruction either in
>> the prologue instruction or the one after the epilogue instruction. WDYT?
> 
> I did some tests with the setp/setm/sete, cpyp/cpym/cpye and
> cpyfp/cpyfm/cpyfe sequences and they all work fine if a software
> breakpoint is set on their main or epilogue instructions. Tested on
> Arm FVP and QEMU 8.2.
> 
> So at least for the emulators, adjusting the breakpoint address isn't
> necessary.
> 

Thanks for investingating that. Looks like it will be simpler then.

Regarding displaced stepping, we can disable displaced stepping temporarily
for these instructions. If we find a convenient way to relocate the whole block
of MOPS instructions, then we can add that later on.