linux/arch/x86/math-emu/status_w.h
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   1/*---------------------------------------------------------------------------+
   2 |  status_w.h                                                               |
   3 |                                                                           |
   4 | Copyright (C) 1992,1993                                                   |
   5 |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
   6 |                       Australia.  E-mail   billm@vaxc.cc.monash.edu.au    |
   7 |                                                                           |
   8 +---------------------------------------------------------------------------*/
   9
  10#ifndef _STATUS_H_
  11#define _STATUS_H_
  12
  13#include "fpu_emu.h"            /* for definition of PECULIAR_486 */
  14
  15#ifdef __ASSEMBLY__
  16#define Const__(x)      $##x
  17#else
  18#define Const__(x)      x
  19#endif
  20
  21#define SW_Backward     Const__(0x8000) /* backward compatibility */
  22#define SW_C3           Const__(0x4000) /* condition bit 3 */
  23#define SW_Top          Const__(0x3800) /* top of stack */
  24#define SW_Top_Shift    Const__(11)     /* shift for top of stack bits */
  25#define SW_C2           Const__(0x0400) /* condition bit 2 */
  26#define SW_C1           Const__(0x0200) /* condition bit 1 */
  27#define SW_C0           Const__(0x0100) /* condition bit 0 */
  28#define SW_Summary      Const__(0x0080) /* exception summary */
  29#define SW_Stack_Fault  Const__(0x0040) /* stack fault */
  30#define SW_Precision    Const__(0x0020) /* loss of precision */
  31#define SW_Underflow    Const__(0x0010) /* underflow */
  32#define SW_Overflow     Const__(0x0008) /* overflow */
  33#define SW_Zero_Div     Const__(0x0004) /* divide by zero */
  34#define SW_Denorm_Op    Const__(0x0002) /* denormalized operand */
  35#define SW_Invalid      Const__(0x0001) /* invalid operation */
  36
  37#define SW_Exc_Mask     Const__(0x27f)  /* Status word exception bit mask */
  38
  39#ifndef __ASSEMBLY__
  40
  41#define COMP_A_gt_B     1
  42#define COMP_A_eq_B     2
  43#define COMP_A_lt_B     3
  44#define COMP_No_Comp    4
  45#define COMP_Denormal   0x20
  46#define COMP_NaN        0x40
  47#define COMP_SNaN       0x80
  48
  49#define status_word() \
  50  ((partial_status & ~SW_Top & 0xffff) | ((top << SW_Top_Shift) & SW_Top))
  51static inline void setcc(int cc)
  52{
  53        partial_status &= ~(SW_C0 | SW_C1 | SW_C2 | SW_C3);
  54        partial_status |= (cc) & (SW_C0 | SW_C1 | SW_C2 | SW_C3);
  55}
  56
  57#ifdef PECULIAR_486
  58   /* Default, this conveys no information, but an 80486 does it. */
  59   /* Clear the SW_C1 bit, "other bits undefined". */
  60#  define clear_C1()  { partial_status &= ~SW_C1; }
  61# else
  62#  define clear_C1()
  63#endif /* PECULIAR_486 */
  64
  65#endif /* __ASSEMBLY__ */
  66
  67#endif /* _STATUS_H_ */
  68