LXR linux-old/arch/s390x/lib/strncpy.S

   1/*
   2 *  arch/s390/kernel/strncpy.S
   3 *    S390 strncpy routine
   4 *
   5 *  S390 version
   6 *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
   7 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   8 */
   9
  10/*
  11 * R2 = address of destination
  12 * R3 = address of source string
  13 * R4 = max number of bytes to copy
  14 */
  15        .globl   strncpy
  16strncpy:
  17        LGR     1,2            # don't touch address in R2
  18        LTR     4,4
  19        JZ      strncpy_exit   # 0 bytes -> nothing to do
  20        SGR     0,0
  21strncpy_loop:
  22        ICM     0,1,0(3)       # ICM sets the cc, IC does not
  23        LA      3,1(3)
  24        STC     0,0(1)
  25        LA      1,1(1)
  26        JZ      strncpy_exit   # ICM inserted a 0x00
  27        BRCTG   4,strncpy_loop # R4 -= 1, jump to strncpy_loop if > 0
  28strncpy_exit:
  29        BR      14
  30
  31