remi.S 1.3 KB

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  1. ;; SPDX-License-Identifier: GPL-2.0-or-later
  2. ;; Copyright 2010 Free Software Foundation, Inc.
  3. ;; Contributed by Bernd Schmidt <bernds@codesourcery.com>.
  4. ;;
  5. #include <linux/linkage.h>
  6. ;; ABI considerations for the divide functions
  7. ;; The following registers are call-used:
  8. ;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5
  9. ;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4
  10. ;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4
  11. ;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4
  12. ;;
  13. ;; In our implementation, divu and remu are leaf functions,
  14. ;; while both divi and remi call into divu.
  15. ;; A0 is not clobbered by any of the functions.
  16. ;; divu does not clobber B2 either, which is taken advantage of
  17. ;; in remi.
  18. ;; divi uses B5 to hold the original return address during
  19. ;; the call to divu.
  20. ;; remi uses B2 and A5 to hold the input values during the
  21. ;; call to divu. It stores B3 in on the stack.
  22. .text
  23. ENTRY(__c6xabi_remi)
  24. stw .d2t2 B3, *B15--[2]
  25. || cmpgt .l1 0, A4, A1
  26. || cmpgt .l2 0, B4, B2
  27. || mv .s1 A4, A5
  28. || call .s2 __c6xabi_divu
  29. [A1] neg .l1 A4, A4
  30. || [B2] neg .l2 B4, B4
  31. || xor .s2x B2, A1, B0
  32. || mv .d2 B4, B2
  33. [B0] addkpc .s2 _divu_ret_1, B3, 1
  34. [!B0] addkpc .s2 _divu_ret_2, B3, 1
  35. nop 2
  36. _divu_ret_1:
  37. neg .l1 A4, A4
  38. _divu_ret_2:
  39. ldw .d2t2 *++B15[2], B3
  40. mpy32 .m1x A4, B2, A6
  41. nop 3
  42. ret .s2 B3
  43. sub .l1 A5, A6, A4
  44. nop 4
  45. ENDPROC(__c6xabi_remi)