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/****************************  clear_input_light.as ***************************

* Author:        Agner Fog

* date created:  2021-05-31

* Last modified: 2021-05-31

* Version:       1.11

* Project:       ForwardCom library libc_light.li

* Description:   clear_input: Clear input buffer for stdin

* This version is for small CPUs with limited capabilities

* The following instructions are avoided: mul, div, push, pop, sys_call.

* Input comes directly from input port 8

* Output to stdout goes directly to output port 10

*

* C declaration:

* void clear_input();

*

* Copyright 2021 GNU General Public License http://www.gnu.org/licenses

*****************************************************************************/

// define input and output port numbers

%stdin_port = 8

%stdin_status_port = 9

%stdout_port = 10

code section execute

_clear_input function public reguse = 0, 0

  // save r1

  int64 sp -= 1*8

  int64 [sp] = r1

  int r1 = 1

  int output(r1,r1,stdin_status_port)  // clear input buffer

  // restore r1

  int64 r1 = [sp]

  int64 sp += 1*8

  return

_clear_input end

code end