aboutsummaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/backend/utils/adt/float.c43
-rw-r--r--src/test/regress/expected/float8.out159
-rw-r--r--src/test/regress/sql/float8.sql29
3 files changed, 221 insertions, 10 deletions
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index 6a717f19bba..84d37de9304 100644
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -1565,7 +1565,7 @@ dpow(PG_FUNCTION_ARGS)
if (unlikely(isinf(result)) && !isinf(arg1) && !isinf(arg2))
float_overflow_error();
- if (unlikely(result == 0.0) && arg1 != 0.0)
+ if (unlikely(result == 0.0) && arg1 != 0.0 && !isinf(arg1) && !isinf(arg2))
float_underflow_error();
PG_RETURN_FLOAT8(result);
@@ -1581,15 +1581,38 @@ dexp(PG_FUNCTION_ARGS)
float8 arg1 = PG_GETARG_FLOAT8(0);
float8 result;
- errno = 0;
- result = exp(arg1);
- if (errno == ERANGE && result != 0 && !isinf(result))
- result = get_float8_infinity();
-
- if (unlikely(isinf(result)) && !isinf(arg1))
- float_overflow_error();
- if (unlikely(result == 0.0))
- float_underflow_error();
+ /*
+ * Handle NaN and Inf cases explicitly. This avoids needing to assume
+ * that the platform's exp() conforms to POSIX for these cases, and it
+ * removes some edge cases for the overflow checks below.
+ */
+ if (isnan(arg1))
+ result = arg1;
+ else if (isinf(arg1))
+ {
+ /* Per POSIX, exp(-Inf) is 0 */
+ result = (arg1 > 0.0) ? arg1 : 0;
+ }
+ else
+ {
+ /*
+ * On some platforms, exp() will not set errno but just return Inf or
+ * zero to report overflow/underflow; therefore, test both cases.
+ */
+ errno = 0;
+ result = exp(arg1);
+ if (unlikely(errno == ERANGE))
+ {
+ if (result != 0.0)
+ float_overflow_error();
+ else
+ float_underflow_error();
+ }
+ else if (unlikely(isinf(result)))
+ float_overflow_error();
+ else if (unlikely(result == 0.0))
+ float_underflow_error();
+ }
PG_RETURN_FLOAT8(result);
}
diff --git a/src/test/regress/expected/float8.out b/src/test/regress/expected/float8.out
index aaef20bcfdc..3957fb58d84 100644
--- a/src/test/regress/expected/float8.out
+++ b/src/test/regress/expected/float8.out
@@ -385,6 +385,158 @@ SELECT power(float8 'NaN', float8 '0');
1
(1 row)
+SELECT power(float8 'inf', float8 '0');
+ power
+-------
+ 1
+(1 row)
+
+SELECT power(float8 '-inf', float8 '0');
+ power
+-------
+ 1
+(1 row)
+
+SELECT power(float8 '0', float8 'inf');
+ power
+-------
+ 0
+(1 row)
+
+SELECT power(float8 '0', float8 '-inf');
+ERROR: zero raised to a negative power is undefined
+SELECT power(float8 '1', float8 'inf');
+ power
+-------
+ 1
+(1 row)
+
+SELECT power(float8 '1', float8 '-inf');
+ power
+-------
+ 1
+(1 row)
+
+SELECT power(float8 '-1', float8 'inf');
+ power
+-------
+ 1
+(1 row)
+
+SELECT power(float8 '-1', float8 '-inf');
+ power
+-------
+ 1
+(1 row)
+
+SELECT power(float8 '0.1', float8 'inf');
+ power
+-------
+ 0
+(1 row)
+
+SELECT power(float8 '-0.1', float8 'inf');
+ power
+-------
+ 0
+(1 row)
+
+SELECT power(float8 '1.1', float8 'inf');
+ power
+----------
+ Infinity
+(1 row)
+
+SELECT power(float8 '-1.1', float8 'inf');
+ power
+----------
+ Infinity
+(1 row)
+
+SELECT power(float8 '0.1', float8 '-inf');
+ power
+----------
+ Infinity
+(1 row)
+
+SELECT power(float8 '-0.1', float8 '-inf');
+ power
+----------
+ Infinity
+(1 row)
+
+SELECT power(float8 '1.1', float8 '-inf');
+ power
+-------
+ 0
+(1 row)
+
+SELECT power(float8 '-1.1', float8 '-inf');
+ power
+-------
+ 0
+(1 row)
+
+SELECT power(float8 'inf', float8 '-2');
+ power
+-------
+ 0
+(1 row)
+
+SELECT power(float8 'inf', float8 '2');
+ power
+----------
+ Infinity
+(1 row)
+
+SELECT power(float8 'inf', float8 'inf');
+ power
+----------
+ Infinity
+(1 row)
+
+SELECT power(float8 'inf', float8 '-inf');
+ power
+-------
+ 0
+(1 row)
+
+SELECT power(float8 '-inf', float8 '-2');
+ power
+-------
+ 0
+(1 row)
+
+SELECT power(float8 '-inf', float8 '-3');
+ power
+-------
+ -0
+(1 row)
+
+SELECT power(float8 '-inf', float8 '2');
+ power
+----------
+ Infinity
+(1 row)
+
+SELECT power(float8 '-inf', float8 '3');
+ power
+-----------
+ -Infinity
+(1 row)
+
+SELECT power(float8 '-inf', float8 'inf');
+ power
+----------
+ Infinity
+(1 row)
+
+SELECT power(float8 '-inf', float8 '-inf');
+ power
+-------
+ 0
+(1 row)
+
-- take exp of ln(f.f1)
SELECT '' AS three, f.f1, exp(ln(f.f1)) AS exp_ln_f1
FROM FLOAT8_TBL f
@@ -396,6 +548,13 @@ SELECT '' AS three, f.f1, exp(ln(f.f1)) AS exp_ln_f1
| 1.2345678901234e-200 | 1.23456789012339e-200
(3 rows)
+-- check edge cases for exp
+SELECT exp('inf'::float8), exp('-inf'::float8), exp('nan'::float8);
+ exp | exp | exp
+----------+-----+-----
+ Infinity | 0 | NaN
+(1 row)
+
-- cube root
SELECT ||/ float8 '27' AS three;
three
diff --git a/src/test/regress/sql/float8.sql b/src/test/regress/sql/float8.sql
index e540f03b072..3a8c737fb28 100644
--- a/src/test/regress/sql/float8.sql
+++ b/src/test/regress/sql/float8.sql
@@ -120,12 +120,41 @@ SELECT power(float8 'NaN', float8 'NaN');
SELECT power(float8 '-1', float8 'NaN');
SELECT power(float8 '1', float8 'NaN');
SELECT power(float8 'NaN', float8 '0');
+SELECT power(float8 'inf', float8 '0');
+SELECT power(float8 '-inf', float8 '0');
+SELECT power(float8 '0', float8 'inf');
+SELECT power(float8 '0', float8 '-inf');
+SELECT power(float8 '1', float8 'inf');
+SELECT power(float8 '1', float8 '-inf');
+SELECT power(float8 '-1', float8 'inf');
+SELECT power(float8 '-1', float8 '-inf');
+SELECT power(float8 '0.1', float8 'inf');
+SELECT power(float8 '-0.1', float8 'inf');
+SELECT power(float8 '1.1', float8 'inf');
+SELECT power(float8 '-1.1', float8 'inf');
+SELECT power(float8 '0.1', float8 '-inf');
+SELECT power(float8 '-0.1', float8 '-inf');
+SELECT power(float8 '1.1', float8 '-inf');
+SELECT power(float8 '-1.1', float8 '-inf');
+SELECT power(float8 'inf', float8 '-2');
+SELECT power(float8 'inf', float8 '2');
+SELECT power(float8 'inf', float8 'inf');
+SELECT power(float8 'inf', float8 '-inf');
+SELECT power(float8 '-inf', float8 '-2');
+SELECT power(float8 '-inf', float8 '-3');
+SELECT power(float8 '-inf', float8 '2');
+SELECT power(float8 '-inf', float8 '3');
+SELECT power(float8 '-inf', float8 'inf');
+SELECT power(float8 '-inf', float8 '-inf');
-- take exp of ln(f.f1)
SELECT '' AS three, f.f1, exp(ln(f.f1)) AS exp_ln_f1
FROM FLOAT8_TBL f
WHERE f.f1 > '0.0';
+-- check edge cases for exp
+SELECT exp('inf'::float8), exp('-inf'::float8), exp('nan'::float8);
+
-- cube root
SELECT ||/ float8 '27' AS three;
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-02 20:32:37 +0000