How can I jump to a relative address, using an offset stored in a register?

Intel/AMD says that this:

mov rax, 0xabc
jmp rax

is not equivalent to this:

jmp 0xabc

Since the first assumes absolute jumps because of the register, and the second assumes relative jumps. My question is, what if I wanted to do a relative jump where the offset is stored in a register such as rdi?

I searched other answers in SO, however they weren't so enlightening.

Solution

You would have to add the base address to the offset to form an absolute address in the register and then jump to that.

For example

    ; jump table contains offsets relative to jump_base
    ; index into jump table is in rax
    lea rcx, [rel jump_table]
    mov ecx, [rcx+rax*4]
    lea rax, [rel jump_base]
    add rax, rcx
    jmp rax
jump_base: