Re: [PATCH 05/33] target/mips: Have check_msa_access() return a boolean

[Philippe Mathieu-Daudé]

On 10/24/21 03:02, Richard Henderson wrote:
> On 10/23/21 2:47 PM, Philippe Mathieu-Daudé wrote:
>> Have check_msa_access() return a boolean value so we can
>> return early if MSA is not enabled.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> ---
>>   target/mips/tcg/msa_translate.c | 20 +++++++++++++-------
>>   1 file changed, 13 insertions(+), 7 deletions(-)
>>
>> diff --git a/target/mips/tcg/msa_translate.c
>> b/target/mips/tcg/msa_translate.c
>> index 3ef912da6b8..9e0a08fe335 100644
>> --- a/target/mips/tcg/msa_translate.c
>> +++ b/target/mips/tcg/msa_translate.c
>> @@ -293,19 +293,19 @@ void msa_translate_init(void)
>>       }
>>   }
>>   -static inline int check_msa_access(DisasContext *ctx)
>> +static inline bool check_msa_access(DisasContext *ctx)
>>   {
>>       if (unlikely((ctx->hflags & MIPS_HFLAG_FPU) &&
>>                    !(ctx->hflags & MIPS_HFLAG_F64))) {
>>           gen_reserved_instruction(ctx);
>> -        return 0;
>> +        return false;
>>       }
>>         if (unlikely(!(ctx->hflags & MIPS_HFLAG_MSA))) {
>>           generate_exception_end(ctx, EXCP_MSADIS);
>> -        return 0;
>> +        return false;
>>       }
> 
> When we return false, we have raised an exception.
> 
>> @@ -354,7 +354,9 @@ static bool gen_msa_BxZ_V(DisasContext *ctx, int
>> wt, int s16, TCGCond cond)
>>   {
>>       TCGv_i64 t0;
>>   -    check_msa_access(ctx);
>> +    if (!check_msa_access(ctx)) {
>> +        return false;
>> +    }
> 
> ... which means that here we should return true, meaning that we have
> recognized the instruction and emitted some code for it.  In this case:
> we have recognized that the instruction is valid but not enabled.
> 
> Otherwise, we will return to decode_opc and (eventually) emit another
> gen_reserved_instruction.

Yes, this is what I intended to do. I incorrectly copied/pasted 'false'
then it spread all over the file. Thanks for catching this.