ldexpf.c File Reference

#include "libm.h"
#include "libm_util.h"
#include "libm_new.h"

Include dependency graph for ldexpf.c:

Go to the source code of this file.

Macros
#define	FN_PROTOTYPE_REF   FN_PROTOTYPE
#define	__amd_handle_errorf   _handle_errorf
#define	__amd_ldexp   OP_LDEXP

Functions
float FN_PROTOTYPE_REF()	ldexpf (float x, int n)

Macro Definition Documentation

__amd_handle_errorf

#define __amd_handle_errorf   _handle_errorf

Definition at line 33 of file ldexpf.c.

__amd_ldexp

#define __amd_ldexp   OP_LDEXP

Definition at line 34 of file ldexpf.c.

FN_PROTOTYPE_REF

#define FN_PROTOTYPE_REF   FN_PROTOTYPE

Definition at line 32 of file ldexpf.c.

Function Documentation

ldexpf()

float FN_PROTOTYPE_REF() ldexpf	(	float	x,
		int	n
	)

Definition at line 40 of file ldexpf.c.

{
    UT32 val,val_x;
    unsigned int sign;
    int exponent;
    val.f32 = x;
    val_x.f32 = x;
    sign = val.u32 & 0x80000000;
    val.u32 = val.u32 & 0x7fffffff;/* remove the sign bit */
 
    if(val.u32 > 0x7f800000)/* x= nan */
        #ifdef WINDOWS
        return __amd_handle_errorf("ldexpf", __amd_ldexp, val_x.u32|0x00400000, _DOMAIN, 0, EDOM, x, (float)n, 2);
        #else
        {
          if(!(val.u32 & 0x00400000)) //x is snan
              return __amd_handle_errorf("ldexpf", __amd_ldexp, val_x.u32|0x00400000, _DOMAIN, AMD_F_INVALID, EDOM, x, (float)n, 2);
          else
              return x;
        }
        #endif
 
    if(val.u32 == 0x7f800000)/* x = +-inf*/
        return x;
 
    if((val.u32 == 0x00000000) || (n==0))/* x= +-0 or n= 0*/
        return x;
 
    exponent = val.u32 >> 23; /* get the exponent */
 
    if(exponent == 0)/*x is denormal*/
    {
        val.f32 = val.f32 * VAL_2PMULTIPLIER_SP;/*multiply by 2^24 to bring it to the normal range*/
        exponent = (val.u32 >> 23); /* get the exponent */
        exponent = exponent + n - MULTIPLIER_SP;
        if(exponent < -MULTIPLIER_SP)/*underflow*/
        {
            val.u32 = sign | 0x00000000;
            return __amd_handle_errorf("ldexpf", __amd_ldexp, val.u32, _UNDERFLOW, AMD_F_INEXACT|AMD_F_UNDERFLOW, ERANGE, x, (float)n, 2);
        }
        if(exponent > 254)/*overflow*/
        {
            val.u32 = sign | 0x7f800000;
            return __amd_handle_errorf("ldexpf", __amd_ldexp, val.u32, _OVERFLOW, AMD_F_INEXACT|AMD_F_OVERFLOW, ERANGE, x, (float)n, 2);
        }
 
        exponent += MULTIPLIER_SP;
        val.u32 = sign | (exponent << 23) | (val.u32 & 0x007fffff);
        val.f32 = val.f32 * VAL_2PMMULTIPLIER_SP;
        return val.f32;
    }
 
    exponent += n;
 
    if(exponent < -MULTIPLIER_SP)/*underflow*/
    {
        val.u32 = sign | 0x00000000;
        return __amd_handle_errorf("ldexpf", __amd_ldexp, val.u32, _UNDERFLOW, AMD_F_INEXACT|AMD_F_UNDERFLOW, ERANGE, x, (float)n, 2);
    }
 
    if(exponent < 1)/*x is normal but output is debnormal*/
    {
        exponent += MULTIPLIER_SP;
        val.u32 = sign | (exponent << 23) | (val.u32 & 0x007fffff);
        val.f32 = val.f32 * VAL_2PMMULTIPLIER_SP;
        return val.f32;
    }
 
    if(exponent > 254)/*overflow*/
    {
        val.u32 = sign | 0x7f800000;
        return __amd_handle_errorf("ldexpf", __amd_ldexp, val.u32, _OVERFLOW, AMD_F_INEXACT|AMD_F_OVERFLOW, ERANGE, x, (float)n, 2);
    }
 
    val.u32 = sign | (exponent << 23) | (val.u32 & 0x007fffff);/*x is normal and output is normal*/
    return val.f32;
}