ref: 4ab9c0f5b96c84329a887f7fdbba92066c8ad7a7
dir: /libstd/syscall+linux-x64.s/
.globl sys$syscall
sys$syscall:
/*
hack: We load 6 args regardless of
how many we actually have. This may
load junk values, but if the syscall
doesn't use them, it's going to be
harmless.
*/
movq %rdi,%rax
/* 8(%rsp): hidden type arg */
movq 16(%rsp),%rdi
movq 24(%rsp),%rsi
movq 32(%rsp),%rdx
movq 40(%rsp),%r10
movq 48(%rsp),%r8
movq 56(%rsp),%r9
syscall
ret