Re: [PATCH 8/8] target/sparc: Fix VIS subtraction instructions.

[Nick Bowler]

On 2023-09-28, Richard Henderson <richard.henderson@linaro.org> wrote:
> On 9/24/23 01:03, Nick Bowler wrote:
>> All of the VIS subtraction instructions are documented to subtract the
>> second input operand from the first.  This is also consistent with how
>> the instructions actually work on a real UltraSparc II.
>>
>> But the emulator is implementing the subtraction in the wrong order,
>> subtracting the first input from the second, so the results are wrong
>> in all nontrivial cases.
>>
>> Signed-off-by: Nick Bowler <nbowler@draconx.ca>
>> ---
>>   target/sparc/vis_helper.c | 18 +++++++++---------
>>   1 file changed, 9 insertions(+), 9 deletions(-)
>
> While this patch works, better to use
>
> void tcg_gen_vec_add16_i32(TCGv_i32 d, TCGv_i32 a, TCGv_i32 b);
> void tcg_gen_vec_add16_i64(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b);
> void tcg_gen_vec_add32_i64(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b);
>
> void tcg_gen_vec_sub16_i32(TCGv_i32 d, TCGv_i32 a, TCGv_i32 b);
> void tcg_gen_vec_sub16_i64(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b);
> void tcg_gen_vec_sub32_i64(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b);
>
> from "tcg/tcg-op-gvec.h" and remove the sparc helpers.

OK, I will try to respin this one using these.

Thanks,
  Nick