I worked at Microsoft back when they were looking at the Itanium as a Win64 platform. We were making a .Net console application and one day I was in the lab wh

I worked at Microsoft back when they were looking at the Itanium as a Win64 platform. We were making a .Net console application and one day I was in the lab while our daily test automation was running, and the Itanium machines had a bunch of crazy random chars and colors on the console windows. It wasn't causing tests to fail, but I rolled up my sleeves and debugged the issue, thinking it was probably just some buggy test thing. It turned out we were doing something nobody else was doing in .Net at the time, which was to return a structure by value while we were populating the console buffer. Apparently the JIT compiler lost track of which registers it was using to store the struct and overwrote them. In the disassembly it looked like "move some stuff into a register, then move more stuff into the same register". Thought I was losing it for a second. I reckon the moral is don't get into the mindset that the test is always broken. Sometimes it's actually the product.