home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
NeXTSTEP 3.3 (Developer)…68k, x86, SPARC, PA-RISC]
/
NeXTSTEP 3.3 Dev Intel.iso
/
NextDeveloper
/
Headers
/
architecture
/
i386
/
fpu.h
< prev
next >
Wrap
Text File
|
1992-10-14
|
2KB
|
132 lines
/*
* Copyright (c) 1992 NeXT Computer, Inc.
*
* Intel386 Family: Floating Point unit.
*
* HISTORY
*
* 5 October 1992 David E. Bohman at NeXT
* Added names to previously unamed fields in the mantissa.
*
* 5 April 1992 David E. Bohman at NeXT
* Created.
*/
/*
* Data register.
*/
typedef struct fp_data_reg {
unsigned short mant;
unsigned short mant1 :16,
mant2 :16,
mant3 :16;
unsigned short exp :15,
sign :1;
} fp_data_reg_t;
/*
* Data register stack.
*/
typedef struct fp_stack {
fp_data_reg_t ST[8];
} fp_stack_t;
/*
* Register stack tag word.
*/
typedef struct fp_tag {
unsigned short tag0 :2,
tag1 :2,
tag2 :2,
tag3 :2,
tag4 :2,
tag5 :2,
tag6 :2,
tag7 :2;
#define FP_TAG_VALID 0
#define FP_TAG_ZERO 1
#define FP_TAG_SPEC 2
#define FP_TAG_EMPTY 3
} fp_tag_t;
/*
* Status word.
*/
typedef struct fp_status {
unsigned short invalid :1,
denorm :1,
zdiv :1,
ovrfl :1,
undfl :1,
precis :1,
stkflt :1,
errsumm :1,
c0 :1,
c1 :1,
c2 :1,
tos :3,
c3 :1,
busy :1;
} fp_status_t;
/*
* Control word.
*/
typedef struct fp_control {
unsigned short invalid :1,
denorm :1,
zdiv :1,
ovrfl :1,
undfl :1,
precis :1,
:2,
pc :2,
#define FP_PREC_24B 0
#define FP_PREC_53B 2
#define FP_PREC_64B 3
rc :2,
#define FP_RND_NEAR 0
#define FP_RND_DOWN 1
#define FP_RND_UP 2
#define FP_CHOP 3
/*inf*/ :1,
:3;
} fp_control_t;
#import <architecture/i386/sel.h>
/*
* Floating point 'environment'
* used by FSTENV/FLDENV instructions.
*/
typedef struct fp_env {
fp_control_t control;
unsigned short :16;
fp_status_t status;
unsigned short :16;
fp_tag_t tag;
unsigned short :16;
unsigned int ip;
sel_t cs;
unsigned short opcode;
unsigned int dp;
sel_t ds;
unsigned short :16;
} fp_env_t;
/*
* Floating point state
* used by FSAVE/FRSTOR instructions.
*/
typedef struct fp_state {
fp_env_t environ;
fp_stack_t stack;
} fp_state_t;