diff options
Diffstat (limited to 'src/include/utils/float.h')
| -rw-r--r-- | src/include/utils/float.h | 40 |
1 files changed, 15 insertions, 25 deletions
diff --git a/src/include/utils/float.h b/src/include/utils/float.h index fa903b4bf59..fc2a9cf6475 100644 --- a/src/include/utils/float.h +++ b/src/include/utils/float.h @@ -25,13 +25,6 @@ /* Radians per degree, a.k.a. PI / 180 */ #define RADIANS_PER_DEGREE 0.0174532925199432957692 -/* Visual C++ etc lacks NAN, and won't accept 0.0/0.0. */ -#if defined(WIN32) && !defined(NAN) -static const uint32 nan[2] = {0xffffffff, 0x7fffffff}; - -#define NAN (*(const float8 *) nan) -#endif - extern PGDLLIMPORT int extra_float_digits; /* @@ -51,6 +44,16 @@ 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) { @@ -65,36 +68,23 @@ get_float8_infinity(void) return (float8) INFINITY; } -/* - * Routines to provide reasonably platform-independent handling of NaN - * - * We assume that isnan() is available and work per spec. However, generating - * a NaN in the first place is less well standardized; pre-C99 systems tend - * not to have C99's NaN macro. We centralize our workaround for this here. - */ +/* 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) { -#ifdef NAN /* C99 standard way */ return (float4) NAN; -#else - /* Assume we can get a NAN via zero divide */ - return (float4) (0.0 / 0.0); -#endif } static inline float8 get_float8_nan(void) { - /* (float8) NAN doesn't work on some NetBSD/MIPS releases */ -#if defined(NAN) && !(defined(__NetBSD__) && defined(__mips__)) /* C99 standard way */ return (float8) NAN; -#else - /* Assume we can get a NaN via zero divide */ - return (float8) (0.0 / 0.0); -#endif } /* |