shortest_dec.h File Reference

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Macros
#define	DOUBLE_SHORTEST_DECIMAL_LEN   25
#define	FLOAT_SHORTEST_DECIMAL_LEN   16

Functions
int	double_to_shortest_decimal_bufn (double f, char *result)
int	double_to_shortest_decimal_buf (double f, char *result)
char *	double_to_shortest_decimal (double f)
int	float_to_shortest_decimal_bufn (float f, char *result)
int	float_to_shortest_decimal_buf (float f, char *result)
char *	float_to_shortest_decimal (float f)

Macro Definition Documentation

DOUBLE_SHORTEST_DECIMAL_LEN

#define DOUBLE_SHORTEST_DECIMAL_LEN   25

Definition at line 44 of file shortest_dec.h.

FLOAT_SHORTEST_DECIMAL_LEN

#define FLOAT_SHORTEST_DECIMAL_LEN   16

Definition at line 57 of file shortest_dec.h.

Function Documentation

double_to_shortest_decimal()

char* double_to_shortest_decimal

(

double

f

)

Definition at line 1070 of file d2s.c.

{
    char       *const result = (char *) palloc(DOUBLE_SHORTEST_DECIMAL_LEN);
 
    double_to_shortest_decimal_buf(f, result);
    return result;
}

References DOUBLE_SHORTEST_DECIMAL_LEN, double_to_shortest_decimal_buf(), and palloc().

double_to_shortest_decimal_buf()

int double_to_shortest_decimal_buf	(	double	f,
		char *	result
	)

Definition at line 1053 of file d2s.c.

{
    const int   index = double_to_shortest_decimal_bufn(f, result);
 
    /* Terminate the string. */
    Assert(index < DOUBLE_SHORTEST_DECIMAL_LEN);
    result[index] = '\0';
    return index;
}

References Assert, DOUBLE_SHORTEST_DECIMAL_LEN, and double_to_shortest_decimal_bufn().

Referenced by double_to_shortest_decimal(), float8out_internal(), and outDouble().

double_to_shortest_decimal_bufn()

int double_to_shortest_decimal_bufn	(	double	f,
		char *	result
	)

Definition at line 1015 of file d2s.c.

{
    /*
     * Step 1: Decode the floating-point number, and unify normalized and
     * subnormal cases.
     */
    const uint64 bits = double_to_bits(f);
 
    /* Decode bits into sign, mantissa, and exponent. */
    const bool  ieeeSign = ((bits >> (DOUBLE_MANTISSA_BITS + DOUBLE_EXPONENT_BITS)) & 1) != 0;
    const uint64 ieeeMantissa = bits & ((UINT64CONST(1) << DOUBLE_MANTISSA_BITS) - 1);
    const uint32 ieeeExponent = (uint32) ((bits >> DOUBLE_MANTISSA_BITS) & ((1u << DOUBLE_EXPONENT_BITS) - 1));
 
    /* Case distinction; exit early for the easy cases. */
    if (ieeeExponent == ((1u << DOUBLE_EXPONENT_BITS) - 1u) || (ieeeExponent == 0 && ieeeMantissa == 0))
    {
        return copy_special_str(result, ieeeSign, (ieeeExponent != 0), (ieeeMantissa != 0));
    }
 
    floating_decimal_64 v;
    const bool  isSmallInt = d2d_small_int(ieeeMantissa, ieeeExponent, &v);
 
    if (!isSmallInt)
    {
        v = d2d(ieeeMantissa, ieeeExponent);
    }
 
    return to_chars(v, ieeeSign, result);
}

References copy_special_str(), d2d(), d2d_small_int(), DOUBLE_EXPONENT_BITS, DOUBLE_MANTISSA_BITS, double_to_bits(), and to_chars().

Referenced by double_to_shortest_decimal_buf().

float_to_shortest_decimal()

char* float_to_shortest_decimal

(

float

f

)

Definition at line 797 of file f2s.c.

{
    char       *const result = (char *) palloc(FLOAT_SHORTEST_DECIMAL_LEN);
 
    float_to_shortest_decimal_buf(f, result);
    return result;
}

References FLOAT_SHORTEST_DECIMAL_LEN, float_to_shortest_decimal_buf(), and palloc().

float_to_shortest_decimal_buf()

int float_to_shortest_decimal_buf	(	float	f,
		char *	result
	)

Definition at line 780 of file f2s.c.

{
    const int   index = float_to_shortest_decimal_bufn(f, result);
 
    /* Terminate the string. */
    Assert(index < FLOAT_SHORTEST_DECIMAL_LEN);
    result[index] = '\0';
    return index;
}

References Assert, FLOAT_SHORTEST_DECIMAL_LEN, and float_to_shortest_decimal_bufn().

Referenced by float4out(), and float_to_shortest_decimal().

float_to_shortest_decimal_bufn()

int float_to_shortest_decimal_bufn	(	float	f,
		char *	result
	)

Definition at line 742 of file f2s.c.

{
    /*
     * Step 1: Decode the floating-point number, and unify normalized and
     * subnormal cases.
     */
    const uint32 bits = float_to_bits(f);
 
    /* Decode bits into sign, mantissa, and exponent. */
    const bool  ieeeSign = ((bits >> (FLOAT_MANTISSA_BITS + FLOAT_EXPONENT_BITS)) & 1) != 0;
    const uint32 ieeeMantissa = bits & ((1u << FLOAT_MANTISSA_BITS) - 1);
    const uint32 ieeeExponent = (bits >> FLOAT_MANTISSA_BITS) & ((1u << FLOAT_EXPONENT_BITS) - 1);
 
    /* Case distinction; exit early for the easy cases. */
    if (ieeeExponent == ((1u << FLOAT_EXPONENT_BITS) - 1u) || (ieeeExponent == 0 && ieeeMantissa == 0))
    {
        return copy_special_str(result, ieeeSign, (ieeeExponent != 0), (ieeeMantissa != 0));
    }
 
    floating_decimal_32 v;
    const bool  isSmallInt = f2d_small_int(ieeeMantissa, ieeeExponent, &v);
 
    if (!isSmallInt)
    {
        v = f2d(ieeeMantissa, ieeeExponent);
    }
 
    return to_chars(v, ieeeSign, result);
}

References copy_special_str(), f2d(), f2d_small_int(), FLOAT_EXPONENT_BITS, FLOAT_MANTISSA_BITS, float_to_bits(), and to_chars().

Referenced by float_to_shortest_decimal_buf().