strlen.S 2.0 KB

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  1. /* $OpenBSD: strlen.S,v 1.4 2004/10/08 14:42:09 pefo Exp $ */
  2. /*-
  3. * Copyright (c) 1991, 1993
  4. * The Regents of the University of California. All rights reserved.
  5. *
  6. * This code is derived from software contributed to Berkeley by
  7. * Ralph Campbell.
  8. *
  9. * Redistribution and use in source and binary forms, with or without
  10. * modification, are permitted provided that the following conditions
  11. * are met:
  12. * 1. Redistributions of source code must retain the above copyright
  13. * notice, this list of conditions and the following disclaimer.
  14. * 2. Redistributions in binary form must reproduce the above copyright
  15. * notice, this list of conditions and the following disclaimer in the
  16. * documentation and/or other materials provided with the distribution.
  17. * 3. Neither the name of the University nor the names of its contributors
  18. * may be used to endorse or promote products derived from this software
  19. * without specific prior written permission.
  20. *
  21. * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24. * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31. * SUCH DAMAGE.
  32. */
  33. #include "DEFS.h"
  34. /*
  35. * strlen(str)
  36. */
  37. LEAF(strlen, 0)
  38. .set noreorder
  39. PTR_ADDU v1, a0, 1
  40. 1:
  41. lb v0, 0(a0) # get byte from string
  42. PTR_ADDU a0, a0, 1 # increment pointer
  43. bne v0, zero, 1b # continue if not end
  44. nop
  45. j ra
  46. PTR_SUBU v0, a0, v1 # compute length - 1 for '\0' char
  47. END(strlen)