Re: [Qemu-devel] [PATCH v2 3/5] target-arm: convert sar, shl and shr helpers to TCG

[Peter Maydell]

On 21 September 2012 20:33, Aurelien Jarno <address@hidden> wrote:
> +static void gen_sar(TCGv dest, TCGv t0, TCGv t1)
> +{
> +    TCGv tmp1, tmp2, tmp3;
> +    tmp1 = tcg_temp_new_i32();
> +    tcg_gen_andi_i32(tmp1, t1, 0xff);
> +    tmp2 = tcg_const_i32(0x1f);
> +    tmp3 = tcg_const_i32(0);
> +    tcg_gen_movcond_i32(TCG_COND_GTU, tmp1, tmp1, tmp2, tmp2, tmp1);
> +    tcg_temp_free_i32(tmp3);
> +    tcg_temp_free_i32(tmp2);
> +    tcg_gen_andi_i32(tmp1, tmp1, 0x1f);
> +    tcg_gen_sar_i32(dest, t0, tmp1);
> +    tcg_temp_free_i32(tmp1);
> +}

I don't think you need the "tcg_gen_andi_i32(tmp1, tmp1, 0x1f);"
for sar, do you? The movcond is doing "shift = (shift > 31) ? 31 : shift"
so we know it's going to be in [0..31] and the and will do nothing,
right?

thanks
-- PMM