Re: [Qemu-devel] [PATCH RFC v1 03/29] target-arc: SUB, SUB1, SUB2, SUB3, SBC, RSUB, CMP

[Richard Henderson]

On 09/08/2016 03:31 PM, Michael Rolnik wrote:
> +static void gen_sub_Cf(TCGv dest, TCGv src1, TCGv src2)
> +{
> +    TCGv t1 = tcg_temp_new_i32();
> +    TCGv t2 = tcg_temp_new_i32();
> +    TCGv t3 = tcg_temp_new_i32();
> +
> +    tcg_gen_not_tl(t1, src1);       /*  t1 = ~src1                          */
> +    tcg_gen_and_tl(t2, t1, src2);   /*  t2 = ~src1 & src2                   */
> +    tcg_gen_or_tl(t3, t1, src2);    /*  t3 = (~src1 | src2) & dest          */
> +    tcg_gen_and_tl(t3, t3, dest);
> +    tcg_gen_or_tl(t2, t2, t3);      /*  t2 = ~src1 & src2
> +                                           | ~src1 & dest
> +                                           | dest & src2                    */
> +    tcg_gen_shri_tl(cpu_Cf, t2, 31);/*  Cf = t2(31)                         */

Again, this can be done with tcg_gen_sub2_tl.


r~