Re: [Qemu-devel] [PATCH v2 04/11] target-arm: Use setcond and movcond for csel

[Richard Henderson <rth@twiddle.net>]

On 09/07/2015 10:17 AM, Peter Maydell wrote:
>> +    c64->value = tcg_temp_new_i64();
>> +    c64->cond = c32.cond;
>> +    if (c32.cond == TCG_COND_EQ || c32.cond == TCG_COND_NE) {
>> +        tcg_gen_extu_i32_i64(c64->value, c32.value);
>> +    } else {
>> +        tcg_gen_ext_i32_i64(c64->value, c32.value);
>> +    }
>
> Signed extend would work for EQ and NE as well, wouldn't it?

Yes.

> Why prefer the unsigned extension in those cases? If there's
> a reason, it could do with being commented.

I dunno what I was really thinking there.


r~