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06bf0dd6e3
The POSIX spec says that rint() rounds halfway cases to nearest even. Our substitute implementation failed to do that, rather rounding halfway cases away from zero; and it also got some other cases (such as minus zero) wrong. This led to observable cross-platform differences, as reported in bug #12885 from Rich Schaaf; in particular, casting from float to int didn't honor round-to-nearest-even on builds using rint.c. Implement something that attempts to cover all cases per spec, and add some simple regression tests so that we'll notice if any platforms still get this wrong. Although this is a bug fix, no back-patch, as a behavioral change in the back branches was agreed not to be a good idea. Pedro Gimeno Fortea, reviewed by Michael Paquier and myself
104 lines
2.9 KiB
SQL
104 lines
2.9 KiB
SQL
--
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-- INT2
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--
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CREATE TABLE INT2_TBL(f1 int2);
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INSERT INTO INT2_TBL(f1) VALUES ('0 ');
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INSERT INTO INT2_TBL(f1) VALUES (' 1234 ');
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INSERT INTO INT2_TBL(f1) VALUES (' -1234');
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INSERT INTO INT2_TBL(f1) VALUES ('34.5');
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-- largest and smallest values
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INSERT INTO INT2_TBL(f1) VALUES ('32767');
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INSERT INTO INT2_TBL(f1) VALUES ('-32767');
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-- bad input values -- should give errors
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INSERT INTO INT2_TBL(f1) VALUES ('100000');
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INSERT INTO INT2_TBL(f1) VALUES ('asdf');
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INSERT INTO INT2_TBL(f1) VALUES (' ');
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INSERT INTO INT2_TBL(f1) VALUES ('- 1234');
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INSERT INTO INT2_TBL(f1) VALUES ('4 444');
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INSERT INTO INT2_TBL(f1) VALUES ('123 dt');
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INSERT INTO INT2_TBL(f1) VALUES ('');
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SELECT '' AS five, * FROM INT2_TBL;
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SELECT '' AS four, i.* FROM INT2_TBL i WHERE i.f1 <> int2 '0';
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SELECT '' AS four, i.* FROM INT2_TBL i WHERE i.f1 <> int4 '0';
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SELECT '' AS one, i.* FROM INT2_TBL i WHERE i.f1 = int2 '0';
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SELECT '' AS one, i.* FROM INT2_TBL i WHERE i.f1 = int4 '0';
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SELECT '' AS two, i.* FROM INT2_TBL i WHERE i.f1 < int2 '0';
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SELECT '' AS two, i.* FROM INT2_TBL i WHERE i.f1 < int4 '0';
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SELECT '' AS three, i.* FROM INT2_TBL i WHERE i.f1 <= int2 '0';
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SELECT '' AS three, i.* FROM INT2_TBL i WHERE i.f1 <= int4 '0';
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SELECT '' AS two, i.* FROM INT2_TBL i WHERE i.f1 > int2 '0';
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SELECT '' AS two, i.* FROM INT2_TBL i WHERE i.f1 > int4 '0';
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SELECT '' AS three, i.* FROM INT2_TBL i WHERE i.f1 >= int2 '0';
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SELECT '' AS three, i.* FROM INT2_TBL i WHERE i.f1 >= int4 '0';
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-- positive odds
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SELECT '' AS one, i.* FROM INT2_TBL i WHERE (i.f1 % int2 '2') = int2 '1';
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-- any evens
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SELECT '' AS three, i.* FROM INT2_TBL i WHERE (i.f1 % int4 '2') = int2 '0';
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SELECT '' AS five, i.f1, i.f1 * int2 '2' AS x FROM INT2_TBL i;
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SELECT '' AS five, i.f1, i.f1 * int2 '2' AS x FROM INT2_TBL i
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WHERE abs(f1) < 16384;
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SELECT '' AS five, i.f1, i.f1 * int4 '2' AS x FROM INT2_TBL i;
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SELECT '' AS five, i.f1, i.f1 + int2 '2' AS x FROM INT2_TBL i;
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SELECT '' AS five, i.f1, i.f1 + int2 '2' AS x FROM INT2_TBL i
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WHERE f1 < 32766;
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SELECT '' AS five, i.f1, i.f1 + int4 '2' AS x FROM INT2_TBL i;
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SELECT '' AS five, i.f1, i.f1 - int2 '2' AS x FROM INT2_TBL i;
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SELECT '' AS five, i.f1, i.f1 - int2 '2' AS x FROM INT2_TBL i
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WHERE f1 > -32767;
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SELECT '' AS five, i.f1, i.f1 - int4 '2' AS x FROM INT2_TBL i;
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SELECT '' AS five, i.f1, i.f1 / int2 '2' AS x FROM INT2_TBL i;
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SELECT '' AS five, i.f1, i.f1 / int4 '2' AS x FROM INT2_TBL i;
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-- corner cases
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SELECT (-1::int2<<15)::text;
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SELECT ((-1::int2<<15)+1::int2)::text;
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-- check sane handling of INT16_MIN overflow cases
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SELECT (-32768)::int2 * (-1)::int2;
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SELECT (-32768)::int2 / (-1)::int2;
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SELECT (-32768)::int2 % (-1)::int2;
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-- check rounding when casting from float
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SELECT x, x::int2 AS int2_value
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FROM (VALUES (-2.5::float8),
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(-1.5::float8),
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(-0.5::float8),
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(0.0::float8),
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(0.5::float8),
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(1.5::float8),
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(2.5::float8)) t(x);
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