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Diffstat (limited to 'src/include/c.h')
| -rw-r--r-- | src/include/c.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/include/c.h b/src/include/c.h index 6b5e71782b8..24699ae2919 100644 --- a/src/include/c.h +++ b/src/include/c.h @@ -983,6 +983,30 @@ extern void ExceptionalCondition(const char *conditionName, *_start++ = 0; \ } while (0) +/* + * Macros for range-checking float values before converting to integer. + * We must be careful here that the boundary values are expressed exactly + * in the float domain. PG_INTnn_MIN is an exact power of 2, so it will + * be represented exactly; but PG_INTnn_MAX isn't, and might get rounded + * off, so avoid using that. + * The input must be rounded to an integer beforehand, typically with rint(), + * else we might draw the wrong conclusion about close-to-the-limit values. + * These macros will do the right thing for Inf, but not necessarily for NaN, + * so check isnan(num) first if that's a possibility. + */ +#define FLOAT4_FITS_IN_INT16(num) \ + ((num) >= (float4) PG_INT16_MIN && (num) < -((float4) PG_INT16_MIN)) +#define FLOAT4_FITS_IN_INT32(num) \ + ((num) >= (float4) PG_INT32_MIN && (num) < -((float4) PG_INT32_MIN)) +#define FLOAT4_FITS_IN_INT64(num) \ + ((num) >= (float4) PG_INT64_MIN && (num) < -((float4) PG_INT64_MIN)) +#define FLOAT8_FITS_IN_INT16(num) \ + ((num) >= (float8) PG_INT16_MIN && (num) < -((float8) PG_INT16_MIN)) +#define FLOAT8_FITS_IN_INT32(num) \ + ((num) >= (float8) PG_INT32_MIN && (num) < -((float8) PG_INT32_MIN)) +#define FLOAT8_FITS_IN_INT64(num) \ + ((num) >= (float8) PG_INT64_MIN && (num) < -((float8) PG_INT64_MIN)) + /* ---------------------------------------------------------------- * Section 8: random stuff |