fpu_control.h 2.5 KB

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  1. /* FPU control word definitions. PowerPC version.
  2. Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, write to the Free
  14. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  15. 02111-1307 USA. */
  16. #ifndef _FPU_CONTROL_H
  17. #define _FPU_CONTROL_H
  18. /* rounding control */
  19. #define _FPU_RC_NEAREST 0x00 /* RECOMMENDED */
  20. #define _FPU_RC_DOWN 0x03
  21. #define _FPU_RC_UP 0x02
  22. #define _FPU_RC_ZERO 0x01
  23. #define _FPU_MASK_NI 0x04 /* non-ieee mode */
  24. /* masking of interrupts */
  25. #define _FPU_MASK_ZM 0x10 /* zero divide */
  26. #define _FPU_MASK_OM 0x40 /* overflow */
  27. #define _FPU_MASK_UM 0x20 /* underflow */
  28. #define _FPU_MASK_XM 0x08 /* inexact */
  29. #define _FPU_MASK_IM 0x80 /* invalid operation */
  30. #define _FPU_RESERVED 0xffffff00 /* These bits are reserved are not changed. */
  31. /* The fdlibm code requires no interrupts for exceptions. */
  32. #define _FPU_DEFAULT 0x00000000 /* Default value. */
  33. /* IEEE: same as above, but (some) exceptions;
  34. we leave the 'inexact' exception off.
  35. */
  36. #define _FPU_IEEE 0x000000f0
  37. /* Type of the control word. */
  38. typedef unsigned int fpu_control_t __attribute__ ((__mode__ (__SI__)));
  39. /* Macros for accessing the hardware control word. */
  40. #define _FPU_GETCW(__cw) ( { \
  41. union { double d; fpu_control_t cw[2]; } \
  42. tmp __attribute__ ((__aligned__(8))); \
  43. __asm__ ("mffs 0; stfd%U0 0,%0" : "=m" (tmp.d) : : "fr0"); \
  44. (__cw)=tmp.cw[1]; \
  45. tmp.cw[1]; } )
  46. #define _FPU_SETCW(__cw) { \
  47. union { double d; fpu_control_t cw[2]; } \
  48. tmp __attribute__ ((__aligned__(8))); \
  49. tmp.cw[0] = 0xFFF80000; /* More-or-less arbitrary; this is a QNaN. */ \
  50. tmp.cw[1] = __cw; \
  51. __asm__ ("lfd%U0 0,%0; mtfsf 255,0" : : "m" (tmp.d) : "fr0"); \
  52. }
  53. #if 0
  54. /* Default control word set at startup. */
  55. extern fpu_control_t __fpu_control;
  56. #endif
  57. #endif /* _FPU_CONTROL_H */