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postgres/src/include/utils/float.h
Bruce Momjian 451c43974f Update copyright for 2026
Backpatch-through: 14
2026-01-01 13:24:10 -05:00

313 lines
7.1 KiB
C

/*-------------------------------------------------------------------------
*
* float.h
* Definitions for the built-in floating-point types
*
* Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/include/utils/float.h
*
*-------------------------------------------------------------------------
*/
#ifndef FLOAT_H
#define FLOAT_H
#include <math.h>
/* X/Open (XSI) requires <math.h> to provide M_PI, but core POSIX does not */
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
/* Radians per degree, a.k.a. PI / 180 */
#define RADIANS_PER_DEGREE 0.0174532925199432957692
extern PGDLLIMPORT int extra_float_digits;
/*
* Utility functions in float.c
*/
pg_noreturn extern void float_overflow_error(void);
pg_noreturn extern void float_underflow_error(void);
pg_noreturn extern void float_zero_divide_error(void);
extern int is_infinite(float8 val);
extern float8 float8in_internal(char *num, char **endptr_p,
const char *type_name, const char *orig_string,
struct Node *escontext);
extern float4 float4in_internal(char *num, char **endptr_p,
const char *type_name, const char *orig_string,
struct Node *escontext);
extern char *float8out_internal(float8 num);
extern int float4_cmp_internal(float4 a, float4 b);
extern int float8_cmp_internal(float8 a, float8 b);
/*
* Postgres requires IEEE-standard float arithmetic, including infinities
* and NaNs. We used to support pre-C99 compilers on which <math.h> might
* not supply the standard macros INFINITY and NAN. We no longer do so,
* but these wrapper functions are still preferred over using those macros
* directly.
*
* If you change these functions, see copies in interfaces/ecpg/ecpglib/data.c.
*/
static inline float4
get_float4_infinity(void)
{
/* C99 standard way */
return (float4) INFINITY;
}
static inline float8
get_float8_infinity(void)
{
/* C99 standard way */
return (float8) INFINITY;
}
/* The C standard allows implementations to omit NAN, but we don't */
#ifndef NAN
#error "Postgres requires support for IEEE quiet NaNs"
#endif
static inline float4
get_float4_nan(void)
{
/* C99 standard way */
return (float4) NAN;
}
static inline float8
get_float8_nan(void)
{
/* C99 standard way */
return (float8) NAN;
}
/*
* Floating-point arithmetic with overflow/underflow reported as errors
*
* There isn't any way to check for underflow of addition/subtraction
* because numbers near the underflow value have already been rounded to
* the point where we can't detect that the two values were originally
* different, e.g. on x86, '1e-45'::float4 == '2e-45'::float4 ==
* 1.4013e-45.
*/
static inline float4
float4_pl(const float4 val1, const float4 val2)
{
float4 result;
result = val1 + val2;
if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2))
float_overflow_error();
return result;
}
static inline float8
float8_pl(const float8 val1, const float8 val2)
{
float8 result;
result = val1 + val2;
if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2))
float_overflow_error();
return result;
}
static inline float4
float4_mi(const float4 val1, const float4 val2)
{
float4 result;
result = val1 - val2;
if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2))
float_overflow_error();
return result;
}
static inline float8
float8_mi(const float8 val1, const float8 val2)
{
float8 result;
result = val1 - val2;
if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2))
float_overflow_error();
return result;
}
static inline float4
float4_mul(const float4 val1, const float4 val2)
{
float4 result;
result = val1 * val2;
if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2))
float_overflow_error();
if (unlikely(result == 0.0f) && val1 != 0.0f && val2 != 0.0f)
float_underflow_error();
return result;
}
static inline float8
float8_mul(const float8 val1, const float8 val2)
{
float8 result;
result = val1 * val2;
if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2))
float_overflow_error();
if (unlikely(result == 0.0) && val1 != 0.0 && val2 != 0.0)
float_underflow_error();
return result;
}
static inline float4
float4_div(const float4 val1, const float4 val2)
{
float4 result;
if (unlikely(val2 == 0.0f) && !isnan(val1))
float_zero_divide_error();
result = val1 / val2;
if (unlikely(isinf(result)) && !isinf(val1))
float_overflow_error();
if (unlikely(result == 0.0f) && val1 != 0.0f && !isinf(val2))
float_underflow_error();
return result;
}
static inline float8
float8_div(const float8 val1, const float8 val2)
{
float8 result;
if (unlikely(val2 == 0.0) && !isnan(val1))
float_zero_divide_error();
result = val1 / val2;
if (unlikely(isinf(result)) && !isinf(val1))
float_overflow_error();
if (unlikely(result == 0.0) && val1 != 0.0 && !isinf(val2))
float_underflow_error();
return result;
}
/*
* Routines for NaN-aware comparisons
*
* We consider all NaNs to be equal and larger than any non-NaN. This is
* somewhat arbitrary; the important thing is to have a consistent sort
* order.
*/
static inline bool
float4_eq(const float4 val1, const float4 val2)
{
return isnan(val1) ? isnan(val2) : !isnan(val2) && val1 == val2;
}
static inline bool
float8_eq(const float8 val1, const float8 val2)
{
return isnan(val1) ? isnan(val2) : !isnan(val2) && val1 == val2;
}
static inline bool
float4_ne(const float4 val1, const float4 val2)
{
return isnan(val1) ? !isnan(val2) : isnan(val2) || val1 != val2;
}
static inline bool
float8_ne(const float8 val1, const float8 val2)
{
return isnan(val1) ? !isnan(val2) : isnan(val2) || val1 != val2;
}
static inline bool
float4_lt(const float4 val1, const float4 val2)
{
return !isnan(val1) && (isnan(val2) || val1 < val2);
}
static inline bool
float8_lt(const float8 val1, const float8 val2)
{
return !isnan(val1) && (isnan(val2) || val1 < val2);
}
static inline bool
float4_le(const float4 val1, const float4 val2)
{
return isnan(val2) || (!isnan(val1) && val1 <= val2);
}
static inline bool
float8_le(const float8 val1, const float8 val2)
{
return isnan(val2) || (!isnan(val1) && val1 <= val2);
}
static inline bool
float4_gt(const float4 val1, const float4 val2)
{
return !isnan(val2) && (isnan(val1) || val1 > val2);
}
static inline bool
float8_gt(const float8 val1, const float8 val2)
{
return !isnan(val2) && (isnan(val1) || val1 > val2);
}
static inline bool
float4_ge(const float4 val1, const float4 val2)
{
return isnan(val1) || (!isnan(val2) && val1 >= val2);
}
static inline bool
float8_ge(const float8 val1, const float8 val2)
{
return isnan(val1) || (!isnan(val2) && val1 >= val2);
}
static inline float4
float4_min(const float4 val1, const float4 val2)
{
return float4_lt(val1, val2) ? val1 : val2;
}
static inline float8
float8_min(const float8 val1, const float8 val2)
{
return float8_lt(val1, val2) ? val1 : val2;
}
static inline float4
float4_max(const float4 val1, const float4 val2)
{
return float4_gt(val1, val2) ? val1 : val2;
}
static inline float8
float8_max(const float8 val1, const float8 val2)
{
return float8_gt(val1, val2) ? val1 : val2;
}
#endif /* FLOAT_H */