fe_sub.c 1.2 KB

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  1. #include "fe.h"
  2. /*
  3. h = f - g
  4. Can overlap h with f or g.
  5. Preconditions:
  6. |f| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
  7. |g| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
  8. Postconditions:
  9. |h| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
  10. */
  11. void fe_sub(fe h,const fe f,const fe g)
  12. {
  13. crypto_int32 f0 = f[0];
  14. crypto_int32 f1 = f[1];
  15. crypto_int32 f2 = f[2];
  16. crypto_int32 f3 = f[3];
  17. crypto_int32 f4 = f[4];
  18. crypto_int32 f5 = f[5];
  19. crypto_int32 f6 = f[6];
  20. crypto_int32 f7 = f[7];
  21. crypto_int32 f8 = f[8];
  22. crypto_int32 f9 = f[9];
  23. crypto_int32 g0 = g[0];
  24. crypto_int32 g1 = g[1];
  25. crypto_int32 g2 = g[2];
  26. crypto_int32 g3 = g[3];
  27. crypto_int32 g4 = g[4];
  28. crypto_int32 g5 = g[5];
  29. crypto_int32 g6 = g[6];
  30. crypto_int32 g7 = g[7];
  31. crypto_int32 g8 = g[8];
  32. crypto_int32 g9 = g[9];
  33. crypto_int32 h0 = f0 - g0;
  34. crypto_int32 h1 = f1 - g1;
  35. crypto_int32 h2 = f2 - g2;
  36. crypto_int32 h3 = f3 - g3;
  37. crypto_int32 h4 = f4 - g4;
  38. crypto_int32 h5 = f5 - g5;
  39. crypto_int32 h6 = f6 - g6;
  40. crypto_int32 h7 = f7 - g7;
  41. crypto_int32 h8 = f8 - g8;
  42. crypto_int32 h9 = f9 - g9;
  43. h[0] = h0;
  44. h[1] = h1;
  45. h[2] = h2;
  46. h[3] = h3;
  47. h[4] = h4;
  48. h[5] = h5;
  49. h[6] = h6;
  50. h[7] = h7;
  51. h[8] = h8;
  52. h[9] = h9;
  53. }