> Compiler can optimize it any way it wants, > as long as result is the same as unoptimized one.
We have an option for that. It's called -O0. Pretty much all optimization will change the behavior of your program. The important distinction is whether that difference is observable in valid programs. The whole point of langage standards is that they define what constitutes a valid program. By your definition all writes to vairables must translate into a write to memory (for "correct" behavior in multithreaded applications and with signal handlers). This implies all variables are effectively volatile. You can argue that signed overflow is an extension that it's worth supporting by default. Other people (eg. those interested in autovectorization) will argue that it provides useful optimization opportunities. I don't know which of these is better, but either what it's a lot different to saying "never change the behavior of any program. Paul
