> So what can we do? We can make the if-conversion pass avoid emitting
> conditional moves when it results in using additional registers. But
> although we know it's good on arm, we cannot say the same for other
> architectures. However we can add a flag and enable it on arm by
> default.
Ideally
The first if-conversion pass causes performance drop on arm. For
example on this code:
int f(int c)
{
int z = 0;
if( c )
z = 0x;
else
z = 0x;
return z;
}
It tries to transform the conditional code to if_then_else using the
