Bochs/bochs/fpu/softfloat.h

/*============================================================================
This C header file is part of the SoftFloat IEC/IEEE Floating-point Arithmetic
Package, Release 2b.

Written by John R. Hauser.  This work was made possible in part by the
International Computer Science Institute, located at Suite 600, 1947 Center
Street, Berkeley, California 94704.  Funding was partially provided by the
National Science Foundation under grant MIP-9311980.  The original version
of this code was written as part of a project to build a fixed-point vector
processor in collaboration with the University of California at Berkeley,
overseen by Profs. Nelson Morgan and John Wawrzynek.  More information
is available through the Web page `http://www.cs.berkeley.edu/~jhauser/
arithmetic/SoftFloat.html'.

THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort has
been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT TIMES
RESULT IN INCORRECT BEHAVIOR.  USE OF THIS SOFTWARE IS RESTRICTED TO PERSONS
AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ALL LOSSES,
COSTS, OR OTHER PROBLEMS THEY INCUR DUE TO THE SOFTWARE, AND WHO FURTHERMORE
EFFECTIVELY INDEMNIFY JOHN HAUSER AND THE INTERNATIONAL COMPUTER SCIENCE
INSTITUTE (possibly via similar legal warning) AGAINST ALL LOSSES, COSTS, OR
OTHER PROBLEMS INCURRED BY THEIR CUSTOMERS AND CLIENTS DUE TO THE SOFTWARE.

Derivative works are acceptable, even for commercial purposes, so long as
(1) the source code for the derivative work includes prominent notice that
the work is derivative, and (2) the source code includes prominent notice with
these four paragraphs for those parts of this code that are retained.
=============================================================================*/

/*============================================================================
 * Adapted for Bochs (x86 achitecture simulator) by
 *            Stanislav Shwartsman [sshwarts at sourceforge net]
 * ==========================================================================*/

#include <config.h>      /* generated by configure script from config.h.in */

#ifndef _SOFTFLOAT_H_
#define _SOFTFLOAT_H_

#define FLOAT16
#define FLOATX80

/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point types.
*----------------------------------------------------------------------------*/
#ifdef FLOAT16
typedef Bit16u float16;
#endif
typedef Bit32u float32;
typedef Bit64u float64;

/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point class.
*----------------------------------------------------------------------------*/
typedef enum {
    float_zero,
    float_NaN,
    float_negative_inf,
    float_positive_inf,
    float_denormal,
    float_normalized
} float_class_t;

/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point NaN operands handling mode.
*----------------------------------------------------------------------------*/
enum float_nan_handling_mode_t {
    float_larger_significand_nan = 0,	// this mode used by x87 FPU
    float_first_operand_nan = 1		// this mode used by SSE
};

/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point rounding mode.
*----------------------------------------------------------------------------*/
enum float_round_t {
    float_round_nearest_even = 0,
    float_round_down         = 1,
    float_round_up           = 2,
    float_round_to_zero      = 3
};

/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point exception flags.
*----------------------------------------------------------------------------*/
enum float_exception_flag_t {
    float_flag_invalid   = 0x01,
    float_flag_denormal  = 0x02,
    float_flag_divbyzero = 0x04,
    float_flag_overflow  = 0x08,
    float_flag_underflow = 0x10,
    float_flag_inexact   = 0x20
};

#ifdef FLOATX80
#define RAISE_SW_C1 0x0200
#endif

/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point ordering relations
*----------------------------------------------------------------------------*/
enum {
    float_relation_less      = -1,
    float_relation_equal     =  0,
    float_relation_greater   =  1,
    float_relation_unordered =  2
};

/*----------------------------------------------------------------------------
| Options to indicate which negations to perform in float*_muladd()
| Using these differs from negating an input or output before calling
| the muladd function in that this means that a NaN doesn't have its
| sign bit inverted before it is propagated.
*----------------------------------------------------------------------------*/
enum {
    float_muladd_negate_c       = 1,
    float_muladd_negate_product = 2,
    float_muladd_negate_result  = float_muladd_negate_c | float_muladd_negate_product
};

/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point status structure.
*----------------------------------------------------------------------------*/
struct float_status_t
{
#ifdef FLOATX80
    int float_rounding_precision;	/* floatx80 only */
#endif
    int float_rounding_mode;
    int float_exception_flags;
    int float_exception_masks;
    int float_nan_handling_mode;	/* flag register */
    int flush_underflow_to_zero;	/* flag register */
    int denormals_are_zeros;            /* flag register */
};

/*----------------------------------------------------------------------------
| Routine to raise any or all of the software IEC/IEEE floating-point
| exception flags.
*----------------------------------------------------------------------------*/

BX_CPP_INLINE void float_raise(float_status_t &status, int flags)
{
    status.float_exception_flags |= flags;
}

/*----------------------------------------------------------------------------
| Routine to check if any or all of the software IEC/IEEE floating-point
| exceptions are masked.
*----------------------------------------------------------------------------*/

BX_CPP_INLINE int float_exception_masked(const float_status_t &status, int flag)
{
    return status.float_exception_masks & flag;
}

/*----------------------------------------------------------------------------
| Returns current floating point rounding mode specified by status word.
*----------------------------------------------------------------------------*/

BX_CPP_INLINE int get_float_rounding_mode(const float_status_t &status)
{
    return status.float_rounding_mode;
}

/*----------------------------------------------------------------------------
| Returns current floating point precision (floatx80 only).
*----------------------------------------------------------------------------*/

#ifdef FLOATX80
BX_CPP_INLINE int get_float_rounding_precision(const float_status_t &status)
{
    return status.float_rounding_precision;
}
#endif

/*----------------------------------------------------------------------------
| Returns current floating point NaN operands handling mode specified
| by status word.
*----------------------------------------------------------------------------*/

BX_CPP_INLINE int get_float_nan_handling_mode(const float_status_t &status)
{
    return status.float_nan_handling_mode;
}

/*----------------------------------------------------------------------------
| Raise floating point precision lost up flag (floatx80 only).
*----------------------------------------------------------------------------*/

#ifdef FLOATX80
BX_CPP_INLINE void set_float_rounding_up(float_status_t &status)
{
    status.float_exception_flags |= RAISE_SW_C1;
}
#endif

/*----------------------------------------------------------------------------
| Returns 1 if the <denormals-are-zeros> feature is supported;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

BX_CPP_INLINE int get_denormals_are_zeros(const float_status_t &status)
{
    return status.denormals_are_zeros;
}

/*----------------------------------------------------------------------------
| Returns 1 if the <flush-underflow-to-zero> feature is supported;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

BX_CPP_INLINE int get_flush_underflow_to_zero(const float_status_t &status)
{
    return status.flush_underflow_to_zero;
}

/*----------------------------------------------------------------------------
| Software IEC/IEEE integer-to-floating-point conversion routines.
*----------------------------------------------------------------------------*/
float32 int32_to_float32(Bit32s, float_status_t &status);
float64 int32_to_float64(Bit32s);
float32 int64_to_float32(Bit64s, float_status_t &status);
float64 int64_to_float64(Bit64s, float_status_t &status);

/*----------------------------------------------------------------------------
| Software IEC/IEEE single-precision conversion routines.
*----------------------------------------------------------------------------*/
Bit32s float32_to_int32(float32, float_status_t &status);
Bit32s float32_to_int32_round_to_zero(float32, float_status_t &status);
Bit64s float32_to_int64(float32, float_status_t &status);
Bit64s float32_to_int64_round_to_zero(float32, float_status_t &status);
float64 float32_to_float64(float32, float_status_t &status);

/*----------------------------------------------------------------------------
| Software IEC/IEEE single-precision operations.
*----------------------------------------------------------------------------*/
float32 float32_round_to_int(float32, float_status_t &status);
float32 float32_add(float32, float32, float_status_t &status);
float32 float32_sub(float32, float32, float_status_t &status);
float32 float32_mul(float32, float32, float_status_t &status);
float32 float32_div(float32, float32, float_status_t &status);
float32 float32_sqrt(float32, float_status_t &status);
float32 float32_frc(float32, float_status_t &status);
float32 float32_muladd(float32, float32, float32, int flags, float_status_t &status);

BX_CPP_INLINE float32 float32_fmadd(float32 a, float32 b, float32 c, float_status_t &status)
{
  return float32_muladd(a, b, c, 0, status);
}

BX_CPP_INLINE float32 float32_fmsub(float32 a, float32 b, float32 c, float_status_t &status)
{
  return float32_muladd(a, b, c, float_muladd_negate_c, status);
}

BX_CPP_INLINE float32 float32_fnmadd(float32 a, float32 b, float32 c, float_status_t &status)
{
  return float32_muladd(a, b, c, float_muladd_negate_product, status);
}

BX_CPP_INLINE float32 float32_fnmsub(float32 a, float32 b, float32 c, float_status_t &status)
{
  return float32_muladd(a, b, c, float_muladd_negate_result, status);
}

int float32_compare(float32, float32, float_status_t &status);
int float32_compare_quiet(float32, float32, float_status_t &status);

float_class_t float32_class(float32);
int float32_is_signaling_nan(float32);
int float32_is_nan(float32);
int float32_is_denormal(float32);

float32 float32_min(float32 a, float32 b, float_status_t &status);
float32 float32_max(float32 a, float32 b, float_status_t &status);

/*----------------------------------------------------------------------------
| Software IEC/IEEE double-precision conversion routines.
*----------------------------------------------------------------------------*/
Bit32s float64_to_int32(float64, float_status_t &status);
Bit32s float64_to_int32_round_to_zero(float64, float_status_t &status);
Bit64s float64_to_int64(float64, float_status_t &status);
Bit64s float64_to_int64_round_to_zero(float64, float_status_t &status);
float32 float64_to_float32(float64, float_status_t &status);

/*----------------------------------------------------------------------------
| Software IEC/IEEE double-precision operations.
*----------------------------------------------------------------------------*/
float64 float64_round_to_int(float64, float_status_t &status);
float64 float64_add(float64, float64, float_status_t &status);
float64 float64_sub(float64, float64, float_status_t &status);
float64 float64_mul(float64, float64, float_status_t &status);
float64 float64_div(float64, float64, float_status_t &status);
float64 float64_sqrt(float64, float_status_t &status);
float64 float64_frc(float64, float_status_t &status);
float64 float64_muladd(float64, float64, float64, int flags, float_status_t &status);

BX_CPP_INLINE float64 float64_fmadd(float64 a, float64 b, float64 c, float_status_t &status)
{
  return float64_muladd(a, b, c, 0, status);
}

BX_CPP_INLINE float64 float64_fmsub(float64 a, float64 b, float64 c, float_status_t &status)
{
  return float64_muladd(a, b, c, float_muladd_negate_c, status);
}

BX_CPP_INLINE float64 float64_fnmadd(float64 a, float64 b, float64 c, float_status_t &status)
{
  return float64_muladd(a, b, c, float_muladd_negate_product, status);
}

BX_CPP_INLINE float64 float64_fnmsub(float64 a, float64 b, float64 c, float_status_t &status)
{
  return float64_muladd(a, b, c, float_muladd_negate_result, status);
}

int float64_compare(float64, float64, float_status_t &status);
int float64_compare_quiet(float64, float64, float_status_t &status);

float_class_t float64_class(float64);
int float64_is_signaling_nan(float64);
int float64_is_nan(float64);
int float64_is_denormal(float64);

float64 float64_min(float64 a, float64 b, float_status_t &status);
float64 float64_max(float64 a, float64 b, float_status_t &status);

#ifdef FLOAT16
float32 float16_to_float32(float16, float_status_t &status);
float16 float32_to_float16(float32, float_status_t &status);

float_class_t float16_class(float16);
int float16_is_signaling_nan(float16);
int float16_is_nan(float16);
int float16_is_denormal(float16);
#endif

#ifdef FLOATX80

/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point types.
*----------------------------------------------------------------------------*/

#ifdef BX_BIG_ENDIAN
struct floatx80 {	// leave alignment to compiler
    Bit16u exp;
    Bit64u fraction;
};
#else
struct floatx80 {
    Bit64u fraction;
    Bit16u exp;
};
#endif

/*----------------------------------------------------------------------------
| Software IEC/IEEE integer-to-floating-point conversion routines.
*----------------------------------------------------------------------------*/
floatx80 int32_to_floatx80(Bit32s);
floatx80 int64_to_floatx80(Bit64s);

/*----------------------------------------------------------------------------
| Software IEC/IEEE extended double-precision conversion routines.
*----------------------------------------------------------------------------*/
floatx80 float32_to_floatx80(float32, float_status_t &status);
floatx80 float64_to_floatx80(float64, float_status_t &status);

Bit32s floatx80_to_int32(floatx80, float_status_t &status);
Bit32s floatx80_to_int32_round_to_zero(floatx80, float_status_t &status);
Bit64s floatx80_to_int64(floatx80, float_status_t &status);
Bit64s floatx80_to_int64_round_to_zero(floatx80, float_status_t &status);

float32 floatx80_to_float32(floatx80, float_status_t &status);
float64 floatx80_to_float64(floatx80, float_status_t &status);

/*----------------------------------------------------------------------------
| Software IEC/IEEE extended double-precision operations.
*----------------------------------------------------------------------------*/
floatx80 floatx80_round_to_int(floatx80, float_status_t &status);
floatx80 floatx80_add(floatx80, floatx80, float_status_t &status);
floatx80 floatx80_sub(floatx80, floatx80, float_status_t &status);
floatx80 floatx80_mul(floatx80, floatx80, float_status_t &status);
floatx80 floatx80_div(floatx80, floatx80, float_status_t &status);
floatx80 floatx80_sqrt(floatx80, float_status_t &status);

float_class_t floatx80_class(floatx80);
int floatx80_is_signaling_nan(floatx80);
int floatx80_is_nan(floatx80);

#endif  /* FLOATX80 */

#ifdef FLOAT128

#ifdef BX_BIG_ENDIAN
struct float128 {
    Bit64u hi, lo;
};
#else
struct float128 {
    Bit64u lo, hi;
};
#endif

/*----------------------------------------------------------------------------
| Software IEC/IEEE quadruple-precision conversion routines.
*----------------------------------------------------------------------------*/
float128 floatx80_to_float128(floatx80 a, float_status_t &status);
floatx80 float128_to_floatx80(float128 a, float_status_t &status);

float128 int64_to_float128(Bit64s a);

/*----------------------------------------------------------------------------
| Software IEC/IEEE extended double-precision operations.
*----------------------------------------------------------------------------*/
floatx80 floatx80_mul(floatx80 a, float128 b, float_status_t &status);

/*----------------------------------------------------------------------------
| Software IEC/IEEE quadruple-precision operations.
*----------------------------------------------------------------------------*/
float128 float128_add(float128 a, float128 b, float_status_t &status);
float128 float128_sub(float128 a, float128 b, float_status_t &status);
float128 float128_mul(float128 a, float128 b, float_status_t &status);
float128 float128_div(float128 a, float128 b, float_status_t &status);

#endif  /* FLOAT128 */

#endif