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strlen.S

strlen.S 1.6 KB
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  1. /* SPDX-License-Identifier: GPL-2.0 */
    2. 

  2. /* strlen.S: Sparc optimized strlen code
    3. 

  3.  * Hand optimized from GNU libc's strlen
    4. 

  4.  * Copyright (C) 1991,1996 Free Software Foundation
    5. 

  5.  * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net)
    6. 

  6.  * Copyright (C) 1996, 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
    7. 

  7.  */
    8. 

  8. 

  9. #include <linux/linkage.h>
    10. 

  10. #include <asm/asm.h>
    11. 

  11. #include <asm/export.h>
    12. 

  12. 

  13. #define LO_MAGIC 0x01010101
    14. 

  14. #define HI_MAGIC 0x80808080
    15. 

  15. 

  16. 	.text
    17. 

  17. ENTRY(strlen)
    18. 

  18. 	mov	%o0, %o1
    19. 

  19. 	andcc	%o0, 3, %g0
    20. 

  20. 	BRANCH32(be, pt, 9f)
    21. 

  21. 	 sethi	%hi(HI_MAGIC), %o4
    22. 

  22. 	ldub	[%o0], %o5
    23. 

  23. 	BRANCH_REG_ZERO(pn, %o5, 11f)
    24. 

  24. 	 add	%o0, 1, %o0
    25. 

  25. 	andcc	%o0, 3, %g0
    26. 

  26. 	BRANCH32(be, pn, 4f)
    27. 

  27. 	 or	%o4, %lo(HI_MAGIC), %o3
    28. 

  28. 	ldub	[%o0], %o5
    29. 

  29. 	BRANCH_REG_ZERO(pn, %o5, 12f)
    30. 

  30. 	 add	%o0, 1, %o0
    31. 

  31. 	andcc	%o0, 3, %g0
    32. 

  32. 	BRANCH32(be, pt, 5f)
    33. 

  33. 	 sethi	%hi(LO_MAGIC), %o4
    34. 

  34. 	ldub	[%o0], %o5
    35. 

  35. 	BRANCH_REG_ZERO(pn, %o5, 13f)
    36. 

  36. 	 add	%o0, 1, %o0
    37. 

  37. 	BRANCH32(ba, pt, 8f)
    38. 

  38. 	 or	%o4, %lo(LO_MAGIC), %o2
    39. 

  39. 9:
    40. 

  40. 	or	%o4, %lo(HI_MAGIC), %o3
    41. 

  41. 4:
    42. 

  42. 	sethi	%hi(LO_MAGIC), %o4
    43. 

  43. 5:
    44. 

  44. 	or	%o4, %lo(LO_MAGIC), %o2
    45. 

  45. 8:
    46. 

  46. 	ld	[%o0], %o5
    47. 

  47. 2:
    48. 

  48. 	sub	%o5, %o2, %o4
    49. 

  49. 	andcc	%o4, %o3, %g0
    50. 

  50. 	BRANCH32(be, pt, 8b)
    51. 

  51. 	 add	%o0, 4, %o0
    52. 

  52. 

  53. 	/* Check every byte. */
    54. 

  54. 	srl	%o5, 24, %g7
    55. 

  55. 	andcc	%g7, 0xff, %g0
    56. 

  56. 	BRANCH32(be, pn, 1f)
    57. 

  57. 	 add	%o0, -4, %o4
    58. 

  58. 	srl	%o5, 16, %g7
    59. 

  59. 	andcc	%g7, 0xff, %g0
    60. 

  60. 	BRANCH32(be, pn, 1f)
    61. 

  61. 	 add	%o4, 1, %o4
    62. 

  62. 	srl	%o5, 8, %g7
    63. 

  63. 	andcc	%g7, 0xff, %g0
    64. 

  64. 	BRANCH32(be, pn, 1f)
    65. 

  65. 	 add	%o4, 1, %o4
    66. 

  66. 	andcc	%o5, 0xff, %g0
    67. 

  67. 	BRANCH32_ANNUL(bne, pt, 2b)
    68. 

  68. 	 ld	[%o0], %o5
    69. 

  69. 	add	%o4, 1, %o4
    70. 

  70. 1:
    71. 

  71. 	retl
    72. 

  72. 	 sub	%o4, %o1, %o0
    73. 

  73. 11:
    74. 

  74. 	retl
    75. 

  75. 	 mov	0, %o0
    76. 

  76. 12:
    77. 

  77. 	retl
    78. 

  78. 	 mov	1, %o0
    79. 

  79. 13:
    80. 

  80. 	retl
    81. 

  81. 	 mov	2, %o0
    82. 

  82. ENDPROC(strlen)
    83. 

  83. EXPORT_SYMBOL(strlen)
    84. 

  84.