Re: [PATCH v2 04/37] target/riscv: 8-bit Addition & Subtraction Instruction

[LIU Zhiwei]

On 2021/6/11 上午3:39, Richard Henderson wrote:

> On
>       6/10/21 12:58 AM, LIU Zhiwei wrote:
>       
> >   include/tcg/tcg-op-gvec.h              
> >         |  6 ++
> >         
> >           tcg/tcg-op-gvec.c                       | 47 ++++++++++++++++
> >         
> >       
>       
>       Likewise, should be split from the larger patch.
>       
>       
> > +static void gen_addv_mask_i32(TCGv_i32 d,
> >         TCGv_i32 a, TCGv_i32 b, TCGv_i32 m)
> >         
> >         +{
> >         
> >         +    TCGv_i32 t1 = tcg_temp_new_i32();
> >         
> >         +    TCGv_i32 t2 = tcg_temp_new_i32();
> >         
> >         +    TCGv_i32 t3 = tcg_temp_new_i32();
> >         
> >         +
> >         
> >         +    tcg_gen_andc_i32(t1, a, m);
> >         
> >         +    tcg_gen_andc_i32(t2, b, m);
> >         
> >         +    tcg_gen_xor_i32(t3, a, b);
> >         
> >         +    tcg_gen_add_i32(d, t1, t2);
> >         
> >         +    tcg_gen_and_i32(t3, t3, m);
> >         
> >         +    tcg_gen_xor_i32(d, d, t3);
> >         
> >         +
> >         
> >         +    tcg_temp_free_i32(t1);
> >         
> >         +    tcg_temp_free_i32(t2);
> >         
> >         +    tcg_temp_free_i32(t3);
> >         
> >         +}
> >         
> >         +
> >         
> >         +void tcg_gen_vec_add8_i32(TCGv_i32 d, TCGv_i32 a, TCGv_i32 b)
> >         
> >         +{
> >         
> >         +    TCGv_i32 m = tcg_constant_i32((int32_t)dup_const(MO_8,
> >         0x80));
> >         
> >         +    gen_addv_mask_i32(d, a, b, m);
> >         
> >         +}
> >         
> >       
>       
>       There will only ever be one use; we might as well merge them.
>       
>     
    OK
> The
>       cast is unnecessary.
>       
>

I meet compiler error report without cast. So I just keep it.

../tcg/tcg-op-gvec.c: In function ‘tcg_gen_vec_sub8_i32’:
/home/roman/git/qemu/include/tcg/tcg.h:1327:5: error: overflow in implicit constant conversion [-Werror=overflow]
     (__builtin_constant_p(VECE)                                    \
     ^
../tcg/tcg-op-gvec.c:1947:35: note: in expansion of macro ‘dup_const’
     TCGv_i32 m = tcg_constant_i32(dup_const(MO_8, 0x80));
                                   ^~~~~~~~~
cc1: all warnings being treated as errors

Thanks,
Zhiwei

>       
>       
>       r~
>       
>