marian <marian@xxxxxxxxxxxx> writes: > crxor 6,6,6 <<<< WHY <<<<<< > bl sprintf The various PPC ABIs are unreasonably complicated. The crxor instruction is required by some of them. It is used when calling a function which takes a variable number of arguments. crxor is used to indicate that no floating point arguments were passed. creqv is used to indicate that at least one floating point argument was passed. The varargs function checks the condition register to see whether it has to push the floating point parameter registers on the stack in order to let va_arg work correctly. Since most varargs functions do not have any floating point arguments, it is usually a good tradeoff to have one exact instruction in the caller to save several memory operations in the callee. If you prefer a different tradeoff, you can fool with the -mcall-XXX options. Ian
