> to preserve the ability to call functions without prototypes, you pass the arguments in registers and then immediately write them back to the stack.
"Back" to the stack is a big assumption. A lot of the time, there is no reason an argument would be on the stack in the first place; or even if it is a spilled variable, it usually wouldn't be in the right place (without some fairly uselessly clever stack layout), so it's just a matter of whether the caller or callee does the write.
"Back" to the stack is a big assumption. A lot of the time, there is no reason an argument would be on the stack in the first place; or even if it is a spilled variable, it usually wouldn't be in the right place (without some fairly uselessly clever stack layout), so it's just a matter of whether the caller or callee does the write.