Denormalized floating point numbers: which operations trigger expensive special cases?

Question

Denormalized floating point numbers require expensive special handling in some operations (additions, multiplications). While this is well-known, it seems to me that there are also many comparably simple operations might not be affected by such a penalty. I haven't been able to find a good overview of what things are "safe" on different platforms ans was wondering if others here know more. I am especially interested in the answer for x86-64 and CUDA/PTX, for the following classes of operations.

• Floating point comparison
• Absolute value
• Rounding operations (ceil, floor, trunc, round)
• Conversion (single ↔ double, float ↔ integer)