[PATCH] rs6000: ICE in unrecognizable insn when using -mpower10

[Peter Bergner]

On 7/24/20 6:32 AM, Segher Boessenkool wrote:
> On Thu, Jul 23, 2020 at 08:15:42PM -0500, Peter Bergner wrote:
>> +  /* If the user explicitly uses -mpower10, ensure our ISA flags are
>> +     compatible with it.  */
>> +  if (TARGET_POWER10
>> +      && (rs6000_isa_flags_explicit & OPTION_MASK_POWER10) != 0
>> +      && (processor_target_table[cpu_index].target_enable
>> +	  & OPTION_MASK_POWER10) == 0)
>> +    error ("%qs requires %qs", "-mpower10", "-mcpu=power10");
> 
> This still allows -mpower10 without corresponding -mcpu=.  We should
> just remove this command like flag (but keep the internal flag); for
> power10 we can do that without any issues, it is new (some testcases
> will need fixing, but it is that: fixing).

I think our gcc driver will always pass a -mcpu= option to the compiler.
That said, I too would prefer not even having the option.  However, I
don't know how to remove the -mpower10 option but keep the flag.
You had mentioned -mdirect-move  as one that had bee removed, but
you actually only get a warning if you try and use that option, not
an error, so it hasn't actually been removed.

Peter