fenv.h

Go to the documentation of this file.

#ifndef FENV_H
#define FENV_H

#include <stddef.h>

#define FE_INVALID      1
#define FE_DENORMAL     2
#define FE_DIVBYZERO    4
#define FE_OVERFLOW     8
#define FE_UNDERFLOW    16
#define FE_INEXACT      32
#define FE_ALL_EXCEPT   (FE_INVALID | FE_DENORMAL | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT)

#define FE_TONEAREST    0
#define FE_DOWNWARD     1
#define FE_UPWARD       2
#define FE_TOWARDZERO   3


typedef struct fcontrol_t
{
    unsigned char invalid_operation : 1;
    unsigned char denormalized_operand : 1;
    unsigned char zero_divide : 1;
    unsigned char overflow : 1;
    unsigned char underflow : 1;
    unsigned char precision : 1;
    unsigned char : 2;
    unsigned char precision_control : 2;
    unsigned char rounding_control : 2;
    unsigned char infinity_control : 1;
    unsigned char : 3;
} fcontrol_t;


typedef struct fexcept_t
{
    unsigned char invalid_operation : 1;
    unsigned char denormalized_operand : 1;
    unsigned char zero_divide : 1;
    unsigned char overflow : 1;
    unsigned char underflow : 1;
    unsigned char precision : 1;
    unsigned char stack_fault : 1;
    unsigned char error_summary_status : 1;
    unsigned char condition_code_0: 1;
    unsigned char condition_code_1: 1;
    unsigned char condition_code_2: 1;
    unsigned char top_of_stack_pointer : 3;
    unsigned char condition_code_3: 1;
    unsigned char busy : 1;
} fexcept_t;


typedef struct ftag_word_t
{
    unsigned char tag0 : 2;
    unsigned char tag1 : 2;
    unsigned char tag2 : 2;
    unsigned char tag3 : 2;
    unsigned char tag4 : 2;
    unsigned char tag5 : 2;
    unsigned char tag6 : 2;
    unsigned char tag7 : 2;
} ftag_word_t;


typedef struct fenv_t
{
    fcontrol_t control_word;
    unsigned short unused1;
    fexcept_t status_word;
    unsigned short unused2;
    ftag_word_t tag_word;
    unsigned short unused3;
    unsigned int instruction_pointer_offset;
    unsigned short instruction_pointer_selector;
    unsigned short opcode : 11;
    unsigned char five_zeros : 5;
    unsigned int data_pointer_offset;
    unsigned short data_pointer_selector;
    unsigned short unused4;
} fenv_t;


extern const fenv_t * env;


#define FE_DFL_ENV (env)

#ifdef __cplusplus
extern "C" {
#endif

// Floating-point exceptions


int feclearexcept(int excepts);


int fegetexceptflag(fexcept_t *flagp, int excepts);


int feraiseexcept(int excepts);


int fesetexceptflag(const fexcept_t *flagp, int excepts);


int fetestexcept(int excepts);

// Rounding direction


int fegetround(void);


int fesetround(int round);

// Entire environment


int fegetenv(fenv_t *envp);


int fesetenv(const fenv_t *envp);


int feholdexcept(fenv_t *envp);


int feupdateenv(const fenv_t *envp);

#ifdef __cplusplus
}
#endif

// Additional content


#define __FPU_TAG_WORD_VALID        0

#define __FPU_TAG_ZERO              1

#define __FPU_TAG_SPECIAL           2

#define __FPU_TAG_EMPTY             3

#define __FPU_PRECISION_SINGLE      0
#define __FPU_PRECISION_DOUBLE      1
#define __FPU_PRECISION_EXTENDED    3

#define __FPU_ROUNDING_NEAREST_EVEN     0
#define __FPU_ROUNDING_FLOOR            1
#define __FPU_ROUNDING_CEIL             2
#define __FPU_ROUNDING_TRUNCATE         3

#define __FPU_INFINITY_CONTROL_PROJECTIVE   0
#define __FPU_INFINITY_CONTROL_AFFINE       1

#ifdef __cplusplus
extern "C" {
#endif


fcontrol_t __FPU_read_control_word();


void __FPU_write_control_word(fcontrol_t control_word);


fenv_t __FPU_read_environment();


void __FPU_write_environment(fenv_t environment);


fexcept_t __FPU_read_status_word();

void __FPU_clear_exceptions();

#ifdef __cplusplus
}
#endif

#endif // FENV_H