strcpy-700.S 1.5 KB

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  1. /*
  2. * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  3. *
  4. * This program is free software; you can redistribute it and/or modify
  5. * it under the terms of the GNU General Public License version 2 as
  6. * published by the Free Software Foundation.
  7. */
  8. /* If dst and src are 4 byte aligned, copy 8 bytes at a time.
  9. If the src is 4, but not 8 byte aligned, we first read 4 bytes to get
  10. it 8 byte aligned. Thus, we can do a little read-ahead, without
  11. dereferencing a cache line that we should not touch.
  12. Note that short and long instructions have been scheduled to avoid
  13. branch stalls.
  14. The beq_s to r3z could be made unaligned & long to avoid a stall
  15. there, but the it is not likely to be taken often, and it
  16. would also be likey to cost an unaligned mispredict at the next call. */
  17. #include <linux/linkage.h>
  18. ENTRY_CFI(strcpy)
  19. or r2,r0,r1
  20. bmsk_s r2,r2,1
  21. brne.d r2,0,charloop
  22. mov_s r10,r0
  23. ld_s r3,[r1,0]
  24. mov r8,0x01010101
  25. bbit0.d r1,2,loop_start
  26. ror r12,r8
  27. sub r2,r3,r8
  28. bic_s r2,r2,r3
  29. tst_s r2,r12
  30. bne r3z
  31. mov_s r4,r3
  32. .balign 4
  33. loop:
  34. ld.a r3,[r1,4]
  35. st.ab r4,[r10,4]
  36. loop_start:
  37. ld.a r4,[r1,4]
  38. sub r2,r3,r8
  39. bic_s r2,r2,r3
  40. tst_s r2,r12
  41. bne_s r3z
  42. st.ab r3,[r10,4]
  43. sub r2,r4,r8
  44. bic r2,r2,r4
  45. tst r2,r12
  46. beq loop
  47. mov_s r3,r4
  48. #ifdef __LITTLE_ENDIAN__
  49. r3z: bmsk.f r1,r3,7
  50. lsr_s r3,r3,8
  51. #else
  52. r3z: lsr.f r1,r3,24
  53. asl_s r3,r3,8
  54. #endif
  55. bne.d r3z
  56. stb.ab r1,[r10,1]
  57. j_s [blink]
  58. .balign 4
  59. charloop:
  60. ldb.ab r3,[r1,1]
  61. brne.d r3,0,charloop
  62. stb.ab r3,[r10,1]
  63. j [blink]
  64. END_CFI(strcpy)