If we have this situation:
jCC L1
jmp L2
L1:
...
L2:
...
We can get a small performance boost by emitting this instead:
jnCC L2
L1:
...
L2:
...
This testcase shows an example of this:
float func(float x, float y) {
double product = (double)x * y;
if (product == 0.0)
return product;
return product - 1.0;
}
llvm-svn: 101075
(X != null) | (Y != null) --> (X|Y) != 0
(X == null) & (Y == null) --> (X|Y) == 0
so that instcombine can stop doing this for pointers. This is part of PR3351,
which is a case where instcombine doing this for pointers (inserting ptrtoint)
is pessimizing code.
llvm-svn: 92406
Dan Gohman