On Fri, 18 Sep 2015, Marc Glisse wrote:
+(bit_and:c (op @0 @1) (op @0 @2))
:c seems useless here. On the other hand, it might make sense to use op:s
since this is mostly useful if it removes the 2 original comparisons.
As I was saying, :c is useless.
(x:c y z)
is replaced by two copies of the transformation, one with
(x y z)
and the other with
(x z y)
In your transformation, both versions would be equivalent, so the second
one is redundant.
Also, if you have:
a=x<y;
b=x<z;
c=a&b;
reuse(a);
reuse(b);
(i.e. the comparison results are used for more than just this bit_and)
then your transformation may make the code more expensive. To avoid
this, you can write op:s, meaning that the result of op is used only
once.
--
Marc Glisse
