.code64

	.extern THREAD_sp
	
	.global switch_to
	.type switch_to, @function

	// %rdi = (struct thread *) current thread.
	// %rsi = (struct thread *) next thread.
switch_to:
	pushfq

	push %rax
	push %rcx
	push %rdx
	push %rbx
	pushq $0
	push %rbp
	push %rsi
	push %rdi
	push %r8
	push %r9
	push %r10
	push %r11
	push %r12
	push %r13
	push %r14
	push %r15
	
	movq %rsp, THREAD_sp(%rdi)
	movq THREAD_sp(%rsi), %rsp

	pop %r15
	pop %r14
	pop %r13
	pop %r12
	pop %r11
	pop %r10
	pop %r9
	pop %r8
	pop %rdi
	pop %rsi
	pop %rbp
	add $8, %rsp
	pop %rbx
	pop %rdx
	pop %rcx
	pop %rax

	popfq

	ret