These opcodes are only supported as vector operations,
not as advsimd scalar.  Set only_in_vector, and remove
the unreachable implementation of scalar fneg.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/tcg/translate-a64.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index a99f3d0d13..f67360c4c5 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -10816,6 +10816,7 @@ static void disas_simd_two_reg_misc_fp16(DisasContext *s, uint32_t insn)
         break;
     case 0x2f: /* FABS */
     case 0x6f: /* FNEG */
+        only_in_vector = true;
         need_fpst = false;
         break;
     case 0x7d: /* FRSQRTE */
@@ -10877,9 +10878,6 @@ static void disas_simd_two_reg_misc_fp16(DisasContext *s, uint32_t insn)
         case 0x7b: /* FCVTZU */
             gen_helper_advsimd_f16touinth(tcg_res, tcg_op, tcg_fpstatus);
             break;
-        case 0x6f: /* FNEG */
-            tcg_gen_xori_i32(tcg_res, tcg_op, 0x8000);
-            break;
         case 0x7d: /* FRSQRTE */
             gen_helper_rsqrte_f16(tcg_res, tcg_op, tcg_fpstatus);
             break;
-- 
2.43.0

On Tue, 10 Dec 2024 at 16:19, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> These opcodes are only supported as vector operations,
> not as advsimd scalar.  Set only_in_vector, and remove
> the unreachable implementation of scalar fneg.
>
> Reported-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/tcg/translate-a64.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
> index a99f3d0d13..f67360c4c5 100644
> --- a/target/arm/tcg/translate-a64.c
> +++ b/target/arm/tcg/translate-a64.c
> @@ -10816,6 +10816,7 @@ static void disas_simd_two_reg_misc_fp16(DisasContext *s, uint32_t insn)
>          break;
>      case 0x2f: /* FABS */
>      case 0x6f: /* FNEG */
> +        only_in_vector = true;
>          need_fpst = false;
>          break;
>      case 0x7d: /* FRSQRTE */

Also case 0x7f FRSQRT I think, which will currently fall into
a g_assert_not_reached() for the scalar case.

thanks
-- PMM

On 12/11/24 09:44, Peter Maydell wrote:
> On Tue, 10 Dec 2024 at 16:19, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> These opcodes are only supported as vector operations,
>> not as advsimd scalar.  Set only_in_vector, and remove
>> the unreachable implementation of scalar fneg.
>>
>> Reported-by: Peter Maydell <peter.maydell@linaro.org>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>   target/arm/tcg/translate-a64.c | 4 +---
>>   1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
>> index a99f3d0d13..f67360c4c5 100644
>> --- a/target/arm/tcg/translate-a64.c
>> +++ b/target/arm/tcg/translate-a64.c
>> @@ -10816,6 +10816,7 @@ static void disas_simd_two_reg_misc_fp16(DisasContext *s, uint32_t insn)
>>           break;
>>       case 0x2f: /* FABS */
>>       case 0x6f: /* FNEG */
>> +        only_in_vector = true;
>>           need_fpst = false;
>>           break;
>>       case 0x7d: /* FRSQRTE */
> 
> Also case 0x7f FRSQRT I think, which will currently fall into
> a g_assert_not_reached() for the scalar case.
0x7f FSQRT (vector), yes.  I'll fix this case too.


r~