Re: [PATCH v1 5/8] s390x/tcg: Implement BRANCH INDIRECT ON CONDITION (BIC)

[David Hildenbrand]

On 25.09.20 23:45, Richard Henderson wrote:
> On 9/22/20 3:31 AM, David Hildenbrand wrote:
>> +/* BRANCH INDIRECT ON CONDITION */
>> +    C(0xe347, BIC,     RXY_b, MIE2,0, m2_64, 0, 0, bc, 0)
>>  /* BRANCH ON CONDITION */
>>      C(0x0700, BCR,     RR_b,  Z,   0, r2_nz, 0, 0, bc, 0)
>>      C(0x4700, BC,      RX_b,  Z,   0, a2, 0, 0, bc, 0)
>> diff --git a/target/s390x/translate.c b/target/s390x/translate.c
>> index b536491892..383edf7419 100644
>> --- a/target/s390x/translate.c
>> +++ b/target/s390x/translate.c
>> @@ -1626,6 +1626,11 @@ static DisasJumpType op_bc(DisasContext *s, DisasOps 
>> *o)
>>          return DISAS_NEXT;
>>      }
>>  
>> +    /* For BIC the address came from memory, we need to wrap it again. */
>> +    if (s->fields.op2 == 0x47) {
>> +        gen_addi_and_wrap_i64(s, o->in2, o->in2, 0);
>> +    }
> 
> I'm not keen on this sort of per-opcode checks.
> 
> I'd prefer to add an in2_m2_64w() helper that performs the load and then 
> wraps.

Makes sense, thanks!


-- 
Thanks,

David / dhildenb