I have gcc 4.0.2 and 4.1.2 and in the one particular case if I use the fastcall attribute valgrind reports a bunch of errors, and I get a segmentation fault, for which fastcall is key. But I believe it is more than just key, I believe the fastcall attribute to be the cause, since when I run valgrind on my app w/out fastcall, or in a 64-bit environment, valgrind doesn't report anything wrong. I'm using the fastcall attribute in 3 places. One is this stand-alone function, and the other two are pure virtual methods of a class. Oddly enough, the pure virtuals aren't giving me any trouble at all (since I'm very caseful to declare the overrides with like attributes). In all cases the full attributes declaration is: __attribute__((const, nothrow, fastcall)). Could I be using fastcall wrong, or is it just a dangerous attribute to work with? -- View this message in context: http://www.nabble.com/Is-fastcall-broken--tf3995991.html#a11348451 Sent from the gcc - Help mailing list archive at Nabble.com.