func (c *context) set_sp(x uintptr) { c.spr = uint32(x) }
func (c *context) set_lr(x uintptr) { c.lrr = uint32(x) }

// arm does not have frame pointer register.
func (c *context) set_fp(x uintptr) {}

func prepareContextForSigResume(c *context) {
	c.r0 = c.spr
	c.r1 = c.pc
}

func dumpregs(r *context) {
	print("r0   ", hex(r.r0), "\n")
	print("r1   ", hex(r.r1), "\n")
	print("r2   ", hex(r.r2), "\n")

func (c *context) set_ip(x uintptr) { c.rip = uint64(x) }
func (c *context) set_sp(x uintptr) { c.rsp = uint64(x) }
func (c *context) set_fp(x uintptr) { c.rbp = uint64(x) }

func prepareContextForSigResume(c *context) {
	c.r8 = c.rsp
	c.r9 = c.rip
}

func dumpregs(r *context) {
	print("rax     ", hex(r.rax), "\n")
	print("rbx     ", hex(r.rbx), "\n")
	print("rcx     ", hex(r.rcx), "\n")

func (c *context) set_ip(x uintptr) { c.eip = uint32(x) }
func (c *context) set_sp(x uintptr) { c.esp = uint32(x) }

// 386 does not have frame pointer register.
func (c *context) set_fp(x uintptr) {}

func prepareContextForSigResume(c *context) {
	c.edx = c.esp
	c.ecx = c.eip
}

func dumpregs(r *context) {
	print("eax     ", hex(r.eax), "\n")
	print("ebx     ", hex(r.ebx), "\n")
	print("ecx     ", hex(r.ecx), "\n")

func (c *context) set_sp(x uintptr) { c.xsp = uint64(x) }
func (c *context) set_lr(x uintptr) { c.x[30] = uint64(x) }
func (c *context) set_fp(x uintptr) { c.x[29] = uint64(x) }

func prepareContextForSigResume(c *context) {
	c.x[0] = c.xsp
	c.x[1] = c.pc
}

func dumpregs(r *context) {
	print("r0   ", hex(r.x[0]), "\n")
	print("r1   ", hex(r.x[1]), "\n")
	print("r2   ", hex(r.x[2]), "\n")

	// same mechanism for async preemption.
	if ep.context.ip() == abi.FuncPCABI0(sigresume) {
		// sigresume has already been set up by a previous exception.
		return ret
	}
	prepareContextForSigResume(ep.context)
	ep.context.set_sp(gp.m.g0.sched.sp)
	ep.context.set_ip(abi.FuncPCABI0(sigresume))
	return ret
}

// Called by sigtramp from Windows VEH handler.