File: /usr/src/linux/arch/i386/math-emu/status_w.h

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))
51     #define setcc(cc) ({ \
52       partial_status &= ~(SW_C0|SW_C1|SW_C2|SW_C3); \
53       partial_status |= (cc) & (SW_C0|SW_C1|SW_C2|SW_C3); })
54     
55     #ifdef PECULIAR_486
56        /* Default, this conveys no information, but an 80486 does it. */
57        /* Clear the SW_C1 bit, "other bits undefined". */
58     #  define clear_C1()  { partial_status &= ~SW_C1; }
59     # else
60     #  define clear_C1()
61     #endif /* PECULIAR_486 */
62     
63     #endif /* __ASSEMBLY__ */
64     
65     #endif /* _STATUS_H_ */
66