Remove the special cases to prevent minus-zero results in float4 and float8

unary minus operators.  We weren't attempting to prevent minus zero anywhere
else; in view of our gradual trend to make the float datatypes more IEEE
standard compliant, we should allow minus zero here rather than disallow it
elsewhere.

We don't, however, expect that all platforms will produce minus zero, so
we need to adjust the one affected regression test to allow both results.

Per discussion of bug #4660.

(In passing, clean up a couple other minor infelicities in float.c.)
This commit is contained in:
Tom Lane 2009-02-18 19:23:26 +00:00
parent cdd46c7654
commit 86ffdcad1b
3 changed files with 146 additions and 15 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/float.c,v 1.159 2009/01/01 17:23:49 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/float.c,v 1.160 2009/02/18 19:23:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -576,9 +576,7 @@ float4um(PG_FUNCTION_ARGS)
float4 arg1 = PG_GETARG_FLOAT4(0);
float4 result;
result = ((arg1 != 0) ? -(arg1) : arg1);
CHECKFLOATVAL(result, isinf(arg1), true);
result = -arg1;
PG_RETURN_FLOAT4(result);
}
@ -645,9 +643,7 @@ float8um(PG_FUNCTION_ARGS)
float8 arg1 = PG_GETARG_FLOAT8(0);
float8 result;
result = ((arg1 != 0) ? -(arg1) : arg1);
CHECKFLOATVAL(result, isinf(arg1), true);
result = -arg1;
PG_RETURN_FLOAT8(result);
}
@ -703,16 +699,16 @@ float8smaller(PG_FUNCTION_ARGS)
Datum
float4pl(PG_FUNCTION_ARGS)
{
float8 arg1 = PG_GETARG_FLOAT4(0);
float8 arg2 = PG_GETARG_FLOAT4(1);
float4 arg1 = PG_GETARG_FLOAT4(0);
float4 arg2 = PG_GETARG_FLOAT4(1);
float4 result;
result = arg1 + arg2;
/*
* There isn't any way to check for underflow of addition/subtraction
* because numbers near the underflow value have been already been to the
* point where we can't detect the that the two values were originally
* 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.
*/
@ -757,7 +753,6 @@ float4div(PG_FUNCTION_ARGS)
(errcode(ERRCODE_DIVISION_BY_ZERO),
errmsg("division by zero")));
/* Do division in float8, then check for overflow */
result = arg1 / arg2;
CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2), arg1 == 0);
@ -2693,7 +2688,7 @@ width_bucket_float8(PG_FUNCTION_ARGS)
errmsg("operand, lower bound and upper bound cannot be NaN")));
/* Note that we allow "operand" to be infinite */
if (is_infinite(bound1) || is_infinite(bound2))
if (isinf(bound1) || isinf(bound2))
ereport(ERROR,
(errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
errmsg("lower and upper bounds must be finite")));

View File

@ -92,7 +92,7 @@ SELECT f1 AS two, max(f3) AS max_float, min(f3) as min_float
ORDER BY two, max_float, min_float;
two | max_float | min_float
-----+----------------------+-----------------------
1 | 1.2345678901234e+200 | 0
1 | 1.2345678901234e+200 | -0
2 | 0 | -1.2345678901234e+200
(2 rows)
@ -104,7 +104,7 @@ SELECT f1 AS two, max(f3) AS max_float, min(f3) AS min_float
ORDER BY two, max_float, min_float;
two | max_float | min_float
-----+----------------------+-----------------------
1 | 1.2345678901234e+200 | 0
1 | 1.2345678901234e+200 | -0
2 | 0 | -1.2345678901234e+200
(2 rows)

View File

@ -0,0 +1,136 @@
--
-- NUMEROLOGY
-- Test various combinations of numeric types and functions.
--
--
-- Test implicit type conversions
-- This fails for Postgres v6.1 (and earlier?)
-- so let's try explicit conversions for now - tgl 97/05/07
--
CREATE TABLE TEMP_FLOAT (f1 FLOAT8);
INSERT INTO TEMP_FLOAT (f1)
SELECT float8(f1) FROM INT4_TBL;
INSERT INTO TEMP_FLOAT (f1)
SELECT float8(f1) FROM INT2_TBL;
SELECT '' AS ten, f1 FROM TEMP_FLOAT
ORDER BY f1;
ten | f1
-----+-------------
| -2147483647
| -123456
| -32767
| -1234
| 0
| 0
| 1234
| 32767
| 123456
| 2147483647
(10 rows)
-- int4
CREATE TABLE TEMP_INT4 (f1 INT4);
INSERT INTO TEMP_INT4 (f1)
SELECT int4(f1) FROM FLOAT8_TBL
WHERE (f1 > -2147483647) AND (f1 < 2147483647);
INSERT INTO TEMP_INT4 (f1)
SELECT int4(f1) FROM INT2_TBL;
SELECT '' AS nine, f1 FROM TEMP_INT4
ORDER BY f1;
nine | f1
------+--------
| -32767
| -1234
| -1004
| -35
| 0
| 0
| 0
| 1234
| 32767
(9 rows)
-- int2
CREATE TABLE TEMP_INT2 (f1 INT2);
INSERT INTO TEMP_INT2 (f1)
SELECT int2(f1) FROM FLOAT8_TBL
WHERE (f1 >= -32767) AND (f1 <= 32767);
INSERT INTO TEMP_INT2 (f1)
SELECT int2(f1) FROM INT4_TBL
WHERE (f1 >= -32767) AND (f1 <= 32767);
SELECT '' AS five, f1 FROM TEMP_INT2
ORDER BY f1;
five | f1
------+-------
| -1004
| -35
| 0
| 0
| 0
(5 rows)
--
-- Group-by combinations
--
CREATE TABLE TEMP_GROUP (f1 INT4, f2 INT4, f3 FLOAT8);
INSERT INTO TEMP_GROUP
SELECT 1, (- i.f1), (- f.f1)
FROM INT4_TBL i, FLOAT8_TBL f;
INSERT INTO TEMP_GROUP
SELECT 2, i.f1, f.f1
FROM INT4_TBL i, FLOAT8_TBL f;
SELECT DISTINCT f1 AS two FROM TEMP_GROUP ORDER BY 1;
two
-----
1
2
(2 rows)
SELECT f1 AS two, max(f3) AS max_float, min(f3) as min_float
FROM TEMP_GROUP
GROUP BY f1
ORDER BY two, max_float, min_float;
two | max_float | min_float
-----+----------------------+-----------------------
1 | 1.2345678901234e+200 | 0
2 | 0 | -1.2345678901234e+200
(2 rows)
-- GROUP BY a result column name is not legal per SQL92, but we accept it
-- anyway (if the name is not the name of any column exposed by FROM).
SELECT f1 AS two, max(f3) AS max_float, min(f3) AS min_float
FROM TEMP_GROUP
GROUP BY two
ORDER BY two, max_float, min_float;
two | max_float | min_float
-----+----------------------+-----------------------
1 | 1.2345678901234e+200 | 0
2 | 0 | -1.2345678901234e+200
(2 rows)
SELECT f1 AS two, (max(f3) + 1) AS max_plus_1, (min(f3) - 1) AS min_minus_1
FROM TEMP_GROUP
GROUP BY f1
ORDER BY two, min_minus_1;
two | max_plus_1 | min_minus_1
-----+----------------------+-----------------------
1 | 1.2345678901234e+200 | -1
2 | 1 | -1.2345678901234e+200
(2 rows)
SELECT f1 AS two,
max(f2) + min(f2) AS max_plus_min,
min(f3) - 1 AS min_minus_1
FROM TEMP_GROUP
GROUP BY f1
ORDER BY two, min_minus_1;
two | max_plus_min | min_minus_1
-----+--------------+-----------------------
1 | 0 | -1
2 | 0 | -1.2345678901234e+200
(2 rows)
DROP TABLE TEMP_INT2;
DROP TABLE TEMP_INT4;
DROP TABLE TEMP_FLOAT;
DROP TABLE TEMP_GROUP;