diff options
| -rw-r--r-- | src/backend/utils/adt/float.c | 113 |
1 files changed, 84 insertions, 29 deletions
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c index 8f34209843c..a3a989ed289 100644 --- a/src/backend/utils/adt/float.c +++ b/src/backend/utils/adt/float.c @@ -1524,18 +1524,23 @@ dacos(PG_FUNCTION_ARGS) float8 arg1 = PG_GETARG_FLOAT8(0); float8 result; + /* Per the POSIX spec, return NaN if the input is NaN */ + if (isnan(arg1)) + PG_RETURN_FLOAT8(get_float8_nan()); + /* - * We use errno here because the trigonometric functions are cyclic and - * hard to check for underflow. + * The principal branch of the inverse cosine function maps values in the + * range [-1, 1] to values in the range [0, Pi], so we should reject any + * inputs outside that range and the result will always be finite. */ - errno = 0; - result = acos(arg1); - if (errno != 0) + if (arg1 < -1.0 || arg1 > 1.0) ereport(ERROR, (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), errmsg("input is out of range"))); - CHECKFLOATVAL(result, isinf(arg1), true); + result = acos(arg1); + + CHECKFLOATVAL(result, false, true); PG_RETURN_FLOAT8(result); } @@ -1549,14 +1554,23 @@ dasin(PG_FUNCTION_ARGS) float8 arg1 = PG_GETARG_FLOAT8(0); float8 result; - errno = 0; - result = asin(arg1); - if (errno != 0) + /* Per the POSIX spec, return NaN if the input is NaN */ + if (isnan(arg1)) + PG_RETURN_FLOAT8(get_float8_nan()); + + /* + * The principal branch of the inverse sine function maps values in the + * range [-1, 1] to values in the range [-Pi/2, Pi/2], so we should reject + * any inputs outside that range and the result will always be finite. + */ + if (arg1 < -1.0 || arg1 > 1.0) ereport(ERROR, (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), errmsg("input is out of range"))); - CHECKFLOATVAL(result, isinf(arg1), true); + result = asin(arg1); + + CHECKFLOATVAL(result, false, true); PG_RETURN_FLOAT8(result); } @@ -1570,14 +1584,18 @@ datan(PG_FUNCTION_ARGS) float8 arg1 = PG_GETARG_FLOAT8(0); float8 result; - errno = 0; + /* Per the POSIX spec, return NaN if the input is NaN */ + if (isnan(arg1)) + PG_RETURN_FLOAT8(get_float8_nan()); + + /* + * The principal branch of the inverse tangent function maps all inputs to + * values in the range [-Pi/2, Pi/2], so the result should always be + * finite, even if the input is infinite. + */ result = atan(arg1); - if (errno != 0) - ereport(ERROR, - (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), - errmsg("input is out of range"))); - CHECKFLOATVAL(result, isinf(arg1), true); + CHECKFLOATVAL(result, false, true); PG_RETURN_FLOAT8(result); } @@ -1592,14 +1610,17 @@ datan2(PG_FUNCTION_ARGS) float8 arg2 = PG_GETARG_FLOAT8(1); float8 result; - errno = 0; + /* Per the POSIX spec, return NaN if either input is NaN */ + if (isnan(arg1) || isnan(arg2)) + PG_RETURN_FLOAT8(get_float8_nan()); + + /* + * atan2 maps all inputs to values in the range [-Pi, Pi], so the result + * should always be finite, even if the inputs are infinite. + */ result = atan2(arg1, arg2); - if (errno != 0) - ereport(ERROR, - (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), - errmsg("input is out of range"))); - CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2), true); + CHECKFLOATVAL(result, false, true); PG_RETURN_FLOAT8(result); } @@ -1613,14 +1634,33 @@ dcos(PG_FUNCTION_ARGS) float8 arg1 = PG_GETARG_FLOAT8(0); float8 result; + /* Per the POSIX spec, return NaN if the input is NaN */ + if (isnan(arg1)) + PG_RETURN_FLOAT8(get_float8_nan()); + + /* + * cos() is periodic and so theoretically can work for all finite inputs, + * but some implementations may choose to throw error if the input is so + * large that there are no significant digits in the result. So we should + * check for errors. POSIX allows an error to be reported either via + * errno or via fetestexcept(), but currently we only support checking + * errno. (fetestexcept() is rumored to report underflow unreasonably + * early on some platforms, so it's not clear that believing it would be a + * net improvement anyway.) + * + * For infinite inputs, POSIX specifies that the trigonometric functions + * should return a domain error; but we won't notice that unless the + * platform reports via errno, so also explicitly test for infinite + * inputs. + */ errno = 0; result = cos(arg1); - if (errno != 0) + if (errno != 0 || isinf(arg1)) ereport(ERROR, (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), errmsg("input is out of range"))); - CHECKFLOATVAL(result, isinf(arg1), true); + CHECKFLOATVAL(result, false, true); PG_RETURN_FLOAT8(result); } @@ -1634,15 +1674,20 @@ dcot(PG_FUNCTION_ARGS) float8 arg1 = PG_GETARG_FLOAT8(0); float8 result; + /* Per the POSIX spec, return NaN if the input is NaN */ + if (isnan(arg1)) + PG_RETURN_FLOAT8(get_float8_nan()); + + /* Be sure to throw an error if the input is infinite --- see dcos() */ errno = 0; result = tan(arg1); - if (errno != 0) + if (errno != 0 || isinf(arg1)) ereport(ERROR, (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), errmsg("input is out of range"))); result = 1.0 / result; - CHECKFLOATVAL(result, true /* cotan(pi/2) == inf */ , true); + CHECKFLOATVAL(result, true /* cot(0) == Inf */ , true); PG_RETURN_FLOAT8(result); } @@ -1656,14 +1701,19 @@ dsin(PG_FUNCTION_ARGS) float8 arg1 = PG_GETARG_FLOAT8(0); float8 result; + /* Per the POSIX spec, return NaN if the input is NaN */ + if (isnan(arg1)) + PG_RETURN_FLOAT8(get_float8_nan()); + + /* Be sure to throw an error if the input is infinite --- see dcos() */ errno = 0; result = sin(arg1); - if (errno != 0) + if (errno != 0 || isinf(arg1)) ereport(ERROR, (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), errmsg("input is out of range"))); - CHECKFLOATVAL(result, isinf(arg1), true); + CHECKFLOATVAL(result, false, true); PG_RETURN_FLOAT8(result); } @@ -1677,9 +1727,14 @@ dtan(PG_FUNCTION_ARGS) float8 arg1 = PG_GETARG_FLOAT8(0); float8 result; + /* Per the POSIX spec, return NaN if the input is NaN */ + if (isnan(arg1)) + PG_RETURN_FLOAT8(get_float8_nan()); + + /* Be sure to throw an error if the input is infinite --- see dcos() */ errno = 0; result = tan(arg1); - if (errno != 0) + if (errno != 0 || isinf(arg1)) ereport(ERROR, (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), errmsg("input is out of range"))); |