Re: [PATCH] target/mips: Fix loongson multimedia condition instructions

[Jiaxun Yang]

于 2020年3月21日 GMT+08:00 下午6:39:21, "Philippe Mathieu-Daudé" <address@hidden> 写到:
>On 3/21/20 5:56 AM, Jiaxun Yang wrote:
>> Loongson multimedia condition instructions were previously
>implemented as
>> write 0 to rd due to lack of documentation. So I just confirmed with
>Loongson
>> about their encoding and implemented them correctly.
>
>Can you refer to the datasheet in the commit message, or have someone 
>from Loongson Technology, Lemote Tech or with access to the specs ack 
>your patch?

I just confirmed with Loongson guys on IM.

+ Huacai

Hi Huacai,

Could you please acknowledge this change,
Thanks.

--
Jiaxun Yang

>
>> 
>> Signed-off-by: Jiaxun Yang <address@hidden>
>> ---
>>   target/mips/translate.c | 40
>++++++++++++++++++++++++++++++++++------
>>   1 file changed, 34 insertions(+), 6 deletions(-)
>> 
>> diff --git a/target/mips/translate.c b/target/mips/translate.c
>> index d745bd2803..43be8d27b5 100644
>> --- a/target/mips/translate.c
>> +++ b/target/mips/translate.c
>> @@ -5529,6 +5529,8 @@ static void
>gen_loongson_multimedia(DisasContext *ctx, int rd, int rs, int rt)
>>   {
>>       uint32_t opc, shift_max;
>>       TCGv_i64 t0, t1;
>> +    TCGCond cond;
>> +    TCGLabel *lab;
>>   
>>       opc = MASK_LMI(ctx->opcode);
>>       switch (opc) {
>> @@ -5816,7 +5818,7 @@ static void
>gen_loongson_multimedia(DisasContext *ctx, int rd, int rs, int rt)
>>       case OPC_DADD_CP2:
>>           {
>>               TCGv_i64 t2 = tcg_temp_new_i64();
>> -            TCGLabel *lab = gen_new_label();
>> +            lab = gen_new_label();
>>   
>>               tcg_gen_mov_i64(t2, t0);
>>               tcg_gen_add_i64(t0, t1, t2);
>> @@ -5837,7 +5839,7 @@ static void
>gen_loongson_multimedia(DisasContext *ctx, int rd, int rs, int rt)
>>       case OPC_DSUB_CP2:
>>           {
>>               TCGv_i64 t2 = tcg_temp_new_i64();
>> -            TCGLabel *lab = gen_new_label();
>> +            lab = gen_new_label();
>>   
>>               tcg_gen_mov_i64(t2, t0);
>>               tcg_gen_sub_i64(t0, t1, t2);
>> @@ -5862,14 +5864,39 @@ static void
>gen_loongson_multimedia(DisasContext *ctx, int rd, int rs, int rt)
>>   
>>       case OPC_SEQU_CP2:
>>       case OPC_SEQ_CP2:
>> +        cond = TCG_COND_EQ;
>> +        goto do_cc_cond;
>> +        break;
>> +
>>       case OPC_SLTU_CP2:
>> +        cond = TCG_COND_LTU;
>> +        goto do_cc_cond;
>> +        break;
>> +
>>       case OPC_SLT_CP2:
>> +        cond = TCG_COND_LT;
>> +        goto do_cc_cond;
>> +        break;
>> +
>>       case OPC_SLEU_CP2:
>> +        cond = TCG_COND_LEU;
>> +        goto do_cc_cond;
>> +        break;
>> +
>>       case OPC_SLE_CP2:
>> -        /*
>> -         * ??? Document is unclear: Set FCC[CC].  Does that mean the
>> -         * FD field is the CC field?
>> -         */
>> +        cond = TCG_COND_LE;
>> +    do_cc_cond:
>> +        {
>> +            int cc = (ctx->opcode >> 8) & 0x7;
>> +            lab = gen_new_label();
>> +            tcg_gen_ori_i32(fpu_fcr31, fpu_fcr31, 1 <<
>get_fp_bit(cc));
>> +            tcg_gen_brcond_i64(cond, t0, t1, lab);
>> +            tcg_gen_xori_i32(fpu_fcr31, fpu_fcr31, 1 <<
>get_fp_bit(cc));
>> +            gen_set_label(lab);
>> +        }
>> +        goto no_rd;
>> +        break;
>> +
>>       default:
>>           MIPS_INVAL("loongson_cp2");
>>           generate_exception_end(ctx, EXCP_RI);
>> @@ -5878,6 +5905,7 @@ static void
>gen_loongson_multimedia(DisasContext *ctx, int rd, int rs, int rt)
>>   
>>       gen_store_fpr64(ctx, t0, rd);
>>   
>> +no_rd:
>>       tcg_temp_free_i64(t0);
>>       tcg_temp_free_i64(t1);
>>   }
>> 

-- 
Jiaxun Yang