Return value of a C function to ASM

Question

I\'m trying to call a function from within ASM. I know how to call it, but i\'m having trouble finding how to get the return value of this function. An example follows:

Answer 1

Although the answers are sufficient to answer the OP's question, here's an extract covering most cases from DJPP's manpage for completeness:

Return Value

• Integers (of any size up to 32 bits) and pointers are returned in the %eax register.
• Floating point values are returned in the 387 top-of-stack register, st(0).
• Return values of type long long int are returned in %edx:%eax (the most significant word in %edx and the least significant in %eax).
• Returning a structure is complicated and rarely useful; try to avoid it. (Note that this is different from returning a pointer to a structure.)

If your function returns void (e.g. no value), the contents of these registers are not used.