Chapter 5.4, Problem 31CYU

Explanation of Solution

Register conventions of x86:

• The register “ebp” is generally used by the x86-32 for a frame pointer, whether or not the compiler makes use of special frame management instructions.
• The register “eax” is used to return the function values. Any subroutine which modifies registers “ebx”, “esi”, or “edi” must save their old values in memory, and restore them before returning.
• In x86-64, no frame pointer, the register “rsp” is used as the base when accessing data in the stack, and “rbp” is just an ordinary register.
• The first six integer arguments to a subroutine are passed in registers “rdi”, “rsi”, “rdx”, “rcx”, “r8”, and “r9” respectively.
• If there are few arguments, these registers must be saved by the caller if the contents are needed later...