ref: 72154ee31c060546f417db8094554ce8940df181
dir: /lib/c/target/amd64-sysv/longjmp.s/
# Copyright 2011-2012 Nicholas J. Kain, licensed under standard MIT license .file "longjmp" .global longjmp longjmp: mov %rsi,%rax # val will be longjmp return test %rax,%rax jnz 1f inc %rax # if val==0, val=1 per longjmp semantics 1: mov (%rdi),%rbx # rdi is the jmp_buf, restore regs from it mov 8(%rdi),%rbp mov 16(%rdi),%r12 mov 24(%rdi),%r13 mov 32(%rdi),%r14 mov 40(%rdi),%r15 mov 48(%rdi),%rdx # this ends up being the stack pointer mov %rdx,%rsp mov 56(%rdi),%rdx # this is the instruction pointer jmp *%rdx # goto saved address without altering rsp