sp_fint.c 1.8 KB

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  1. /* IEEE754 floating point arithmetic
  2. * single precision
  3. */
  4. /*
  5. * MIPS floating point support
  6. * Copyright (C) 1994-2000 Algorithmics Ltd.
  7. *
  8. * ########################################################################
  9. *
  10. * This program is free software; you can distribute it and/or modify it
  11. * under the terms of the GNU General Public License (Version 2) as
  12. * published by the Free Software Foundation.
  13. *
  14. * This program is distributed in the hope it will be useful, but WITHOUT
  15. * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16. * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  17. * for more details.
  18. *
  19. * You should have received a copy of the GNU General Public License along
  20. * with this program; if not, write to the Free Software Foundation, Inc.,
  21. * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22. *
  23. * ########################################################################
  24. */
  25. #include "ieee754sp.h"
  26. ieee754sp ieee754sp_fint(int x)
  27. {
  28. unsigned xm;
  29. int xe;
  30. int xs;
  31. CLEARCX;
  32. if (x == 0)
  33. return ieee754sp_zero(0);
  34. if (x == 1 || x == -1)
  35. return ieee754sp_one(x < 0);
  36. if (x == 10 || x == -10)
  37. return ieee754sp_ten(x < 0);
  38. xs = (x < 0);
  39. if (xs) {
  40. if (x == (1 << 31))
  41. xm = ((unsigned) 1 << 31); /* max neg can't be safely negated */
  42. else
  43. xm = -x;
  44. } else {
  45. xm = x;
  46. }
  47. xe = SP_MBITS + 3;
  48. if (xm >> (SP_MBITS + 1 + 3)) {
  49. /* shunt out overflow bits
  50. */
  51. while (xm >> (SP_MBITS + 1 + 3)) {
  52. SPXSRSX1();
  53. }
  54. } else {
  55. /* normalize in grs extended single precision
  56. */
  57. while ((xm >> (SP_MBITS + 3)) == 0) {
  58. xm <<= 1;
  59. xe--;
  60. }
  61. }
  62. SPNORMRET1(xs, xe, xm, "fint", x);
  63. }
  64. ieee754sp ieee754sp_funs(unsigned int u)
  65. {
  66. if ((int) u < 0)
  67. return ieee754sp_add(ieee754sp_1e31(),
  68. ieee754sp_fint(u & ~(1 << 31)));
  69. return ieee754sp_fint(u);
  70. }