On Sat, May 30, 2015 at 3:08 PM, aurelio remonda
<aurelioremo...@gmail.com> wrote:
>>> if (op < 4) {
>>> /* Saturating add/subtract. */
>>> + if (!(arm_dc_feature(s, ARM_FEATURE_THUMB_DSP))){
>>> + /* qsub, qadd, qdadd, qdsub are DSP instructions. */
>>> + goto illegal_op;
>>> + }
>>> tmp = load_reg(s, rn);
>>> tmp2 = load_reg(s, rm);
>>> if (op & 1)
>>> @@ -9559,6 +9598,12 @@ static int disas_thumb2_insn(CPUARMState *env,
>>> DisasContext *s, uint16_t insn_hw
>>> gen_revsh(tmp);
>>> break;
>>> case 0x10: /* sel */
>>> + if (!(arm_dc_feature(s, ARM_FEATURE_THUMB_DSP))){
>>> + /* sel is a DSP instruction. */
>>> + /* need to free this so there's no TCG temporary leak
>>> */
>>> + tcg_temp_free_i32(tmp);
>>> + goto illegal_op;
>>> + }
>>> tmp2 = load_reg(s, rm);
>>> tmp3 = tcg_temp_new_i32();
>>> tcg_gen_ld_i32(tmp3, cpu_env, offsetof(CPUARMState,
>>> GE));
>>> @@ -9624,6 +9669,15 @@ static int disas_thumb2_insn(CPUARMState *env,
>>> DisasContext *s, uint16_t insn_hw
>>> }
>>> break;
>>> case 1: /* 16 x 16 -> 32 */
>>> + if (!(arm_dc_feature(s, ARM_FEATURE_THUMB_DSP))){
>>> + /* smlabb, smlabt, smlatb, smlatt, smulbb, smulbt,
>>> smultt
>>> + * and smultb are DSP instructions
>>> + */
>>> + /* need to free this so there's no TCG temporary leak
>>> */
>>
>> Comment un-needed.
>
> Why do you think it's not needed? Any comments are helpful as long as
> they're correct. Thanks
>
Not always. Comments on code are a maintainance burden. It's
preferrable to have the code self document as much as possible so that
changes only need to be applied once - to the code itself. The only
reason to ever call tcg_temp_free is to avoid a leak so its self
explanatory IMO.
Regards,
Peter
