strcmp.S 2.2 KB

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  1. /* $OpenBSD: strcmp.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. * NOTE: this version assumes unsigned chars in order to be "8 bit clean".
  36. */
  37. LEAF(strcmp, 0)
  38. .set noreorder
  39. 1:
  40. lbu t0, 0(a0) # get two bytes and compare them
  41. lbu t1, 0(a1)
  42. beq t0, zero, LessOrEq # end of first string?
  43. nop
  44. bne t0, t1, NotEq
  45. nop
  46. lbu t0, 1(a0) # unroll loop
  47. lbu t1, 1(a1)
  48. beq t0, zero, LessOrEq # end of first string?
  49. PTR_ADDU a0, a0, 2
  50. beq t0, t1, 1b
  51. PTR_ADDU a1, a1, 2
  52. NotEq:
  53. j ra
  54. PTR_SUBU v0, t0, t1
  55. LessOrEq:
  56. j ra
  57. PTR_SUBU v0, zero, t1
  58. END(strcmp)