You missed the second part where article says that "it actually runs much slower than the original version", "wasting two multiplications and one or two additio

You missed the second part where article says that "it actually runs much slower than the original version", "wasting two multiplications and one or two additions", based on idea that compiler is unable to do a very basic optimization, implying that compiler compiler will actually multiply by one. No benchmarks, no checking assembly, just straightforward misinformation.