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.)

diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index bd3601c6087b50f8f68e9ae21da5bfe90d9ca96a..19b570d9c4a0658af5314efea0d0272508123753 100644 (file)
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -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")));

diff --git a/src/test/regress/expected/numerology.out b/src/test/regress/expected/numerology.out
index d404d9db68121049455a14ab3a97abfbed467187..0a2e66e91992b6015c11cf488954cd4abcfd5f53 100644 (file)
--- a/src/test/regress/expected/numerology.out
+++ b/src/test/regress/expected/numerology.out
@@ -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)
 

diff --git a/src/test/regress/expected/numerology_1.out b/src/test/regress/expected/numerology_1.out
new file mode 100644 (file)index 0000000..d404d9d
--- /dev/null
+++ b/src/test/regress/expected/numerology_1.out
@@ -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;