[int_19h]

How common is it, actually? And on what platforms/architectures? It was a common problem back in the day when most code was compiled for x86, since exceptions weren't designed to be zero-cost in that ABI.

For what it's worth, the article itself has this bit:

"Thanks to the zero-cost exception model used in most C++ implementations (see section 5.4 of TR18015), the code in a try block runs without any overhead."

[abainbridge]

It has been at least a 10% effect in the last two things I profiled, which were a simple software rasteriser and a distributed key value store. The other significant benchmarking gotchas I see are: 1) the CPU being in a sleep mode when the test starts and takes a while to get running at full speed, and 2) other stuff running on the machine causing interference. But these two are easy to work around compared to the alignment-sensitivity problem.