On 10/09/2012 08:16 AM, Aurelien Jarno wrote:
>> > +static bool swap_commutative2(TCGArg *p1, TCGArg *p2)
>> > +{
>> > + int sum = 0;
>> > + sum += temps[p1[0]].state == TCG_TEMP_CONST;
>> > + sum += temps[p1[1]].state == TCG_TEMP_CONST;
>> > + sum -= temps[p2[0]].state == TCG_TEMP_CONST;
>> > + sum -= temps[p2[1]].state == TCG_TEMP_CONST;
>> > + if (sum > 0) {
...
> Same comment are for the swap_commutative() patch, otherwise:
While I don't have an explicit test case for swap_commutative2 like
I do for swap_commutative, think about how many conditionals you'd
have to use to write this without using SUM:
if (((temps[p1[0]].state == TCG_TEMP_CONST // if both p1 are const
&& temps[p1[1]].state == TCG_TEMP_CONST
&& !(temps[p2[0]].state == TCG_TEMP_CONST // ... and not both p2
are const
&& temps[p2[1]].state == TCG_TEMP_CONST))
|| ((temps[p1[0]].state == TCG_TEMP_CONST // if either p1 are
const
|| temps[p1[1]].state == TCG_TEMP_CONST)
&& !temps[p2[0]].state == TCG_TEMP_CONST // ... and neither p2
are const
&& !temps[p2[1]].state == TCG_TEMP_CONST))
I don't see how that can possibly be easier to understand.
r~
