> I just don't see how it can be claimed that Rust can be nearly as
  > fast as C when executing the Rust assembly code requires so many
  > times more instructions to be executed!

Well, beyond what others have said here, with performance, it depends on the exact details. For example, our regex library has gotten some upgrades recently, and so on the benchmark game:

  * http://benchmarksgame.alioth.debian.org/u64q/performance.php?test=regexdna
  * http://benchmarksgame.alioth.debian.org/u32/performance.php?test=regexdna
  * http://benchmarksgame.alioth.debian.org/u32q/performance.php?test=regexdna
  * http://benchmarksgame.alioth.debian.org/u64/performance.php?test=regexdna

We're currently the fastest in two of them, and second place in two of them, once to C. But in many of the other benchmarks, we're slower.

At best, a claim like "Rust is as nearly as fast as C" can only be said for broad categories of things. The devil is in the details.