strlen.S 1.9 KB

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  1. /* vi: set sw=8 ts=8: */
  2. /*
  3. * libc/string/sh64/strlen.S
  4. *
  5. * Simplistic strlen() implementation for SHmedia.
  6. *
  7. * Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
  8. *
  9. * All rights reserved.
  10. *
  11. * Redistribution and use in source and binary forms, with or without
  12. * modification, are permitted provided that the following conditions
  13. * are met:
  14. * 1. Redistributions of source code must retain the above copyright
  15. * notice, this list of conditions and the following disclaimer.
  16. * 2. The name of the above contributors may not be
  17. * used to endorse or promote products derived from this software
  18. * without specific prior written permission.
  19. *
  20. * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  21. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23. * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  24. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30. * SUCH DAMAGE.
  31. */
  32. .section .text..SHmedia32,"ax"
  33. .globl strlen
  34. .type strlen,@function
  35. .balign 16
  36. strlen:
  37. ptabs r18, tr4
  38. /*
  39. * Note: We could easily deal with the NULL case here with a simple
  40. * sanity check, though it seems that the behavior we want is to fault
  41. * in the event that r2 == NULL, so we don't bother.
  42. */
  43. /* beqi r2, 0, tr4 */ ! Sanity check
  44. movi -1, r0
  45. pta/l loop, tr0
  46. loop:
  47. ld.b r2, 0, r1
  48. addi r2, 1, r2
  49. addi r0, 1, r0
  50. bnei/l r1, 0, tr0
  51. or r0, r63, r2
  52. blink tr4, r63
  53. .size strlen, . - strlen