The new instructions are used often or seldom depending on whether you count invocations or occurences. There are new instructions that can be used to write a

The new instructions are used often or seldom depending on whether you count invocations or occurences. There are new instructions that can be used to write a constant-time SHA-256 hash function. A program that contains megabytes of code, more than a million instructions, may reasonably contain only a few of those instructions, because it contains only one or two small hash functions. The instructions are important and effective, but occur only a handful of times among a million instructions.