Re: [PATCH v2 66/67] target/arm: Convert FMADD, FMSUB, FNMADD, FNMSUB to decodetree

[Richard Henderson <richard.henderson@linaro.org>]

On 5/28/24 09:15, Peter Maydell wrote:
> On Sat, 25 May 2024 at 00:27, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> These are the only instructions in the 3 source scalar class.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>   target/arm/tcg/a64.decode      |  10 ++
>>   target/arm/tcg/translate-a64.c | 233 ++++++++++++---------------------
>>   2 files changed, 93 insertions(+), 150 deletions(-)
>>
> 
>>   static void disas_data_proc_fp(DisasContext *s, uint32_t insn)
>>   {
>> -    if (extract32(insn, 24, 1)) {
>> -        /* Floating point data-processing (3 source) */
>> -        disas_fp_3src(s, insn);
>> -    } else if (extract32(insn, 21, 1) == 0) {
>> +    if (extract32(insn, 21, 1) == 0) {
>>           /* Floating point to fixed point conversions */
>>           disas_fp_fixed_conv(s, insn);
>>       } else {
> 
> Doesn't this result in the unallocated-encodings in the
> fp-3src class now falling into the "else" clause and
> being mis-decoded as the wrong thing? I think this
> needs to be
> 
>      if (extract32(insn, 24, 1)) {
>          unallocated_encoding();
>      } else if (extract32(insn, 21, 1) == 0) {
>      [etc]

Agreed.


r~