float4_div and float8_div correctly produced zero for zero divided
by infinity, but threw an underflow error for nonzero finite values
divided by infinity. This seems wrong; at the very least it's
inconsistent with the behavior recently implemented for numeric
infinities. Remove the error and allow zero to be returned.
This patch also removes a useless isinf() test from the overflow
checks in these functions (non-Inf divided by Inf can't produce Inf).
Extracted from a larger patch; this seems significant outside the
context of geometric operators, so it deserves its own commit.
Kyotaro Horiguchi
Discussion: https://postgr.es/m/CAGf+fX70rWFOk5cd00uMfa__0yP+vtQg5ck7c2Onb-Yczp0URA@mail.gmail.com
This is more consistent with the IEEE 754 spec and our treatment of
NaNs elsewhere; in particular, the case has always acted that way in
"numeric" arithmetic.
Noted by Dean Rasheed.
Discussion: https://postgr.es/m/3421746.1594927785@sss.pgh.pa.us
check_float4_val() checks after underflow and overflow of values
converted from float8 to float4, but there has never been any regression
tests for that. This brings the coverage of float.h to 100%.
Author: Movead Li
Discussion: https://postgr.es/m/20190822174636998766188@highgo.ca
Now that the ordering of DROP messages ought to be stable everywhere,
we should not need these kluges of hiding DETAIL output just to avoid
unstable ordering. Hiding it's not great for test coverage, so
let's undo that where possible.
In a small number of places, it's necessary to leave it in, for
example because the output might include a variable pg_temp_nnn
schema name. I also left things alone in places where the details
would depend on other regression test scripts, e.g. plpython_drop.sql.
Perhaps buildfarm experience will show this to be a bad idea,
but if so I'd like to know why.
Discussion: https://postgr.es/m/E1h6eep-0001Mw-Vd@gemulon.postgresql.org
We don't care to assume that input of subnormal float values works,
but a stray subnormal value from the upstream Ryu regression test had
been left in the test data by mistake. Remove it.
Per buildfarm member fulmar.
Previously, floating-point output was done by rounding to a specific
decimal precision; by default, to 6 or 15 decimal digits (losing
information) or as requested using extra_float_digits. Drivers that
wanted exact float values, and applications like pg_dump that must
preserve values exactly, set extra_float_digits=3 (or sometimes 2 for
historical reasons, though this isn't enough for float4).
Unfortunately, decimal rounded output is slow enough to become a
noticable bottleneck when dealing with large result sets or COPY of
large tables when many floating-point values are involved.
Floating-point output can be done much faster when the output is not
rounded to a specific decimal length, but rather is chosen as the
shortest decimal representation that is closer to the original float
value than to any other value representable in the same precision. The
recently published Ryu algorithm by Ulf Adams is both relatively
simple and remarkably fast.
Accordingly, change float4out/float8out to output shortest decimal
representations if extra_float_digits is greater than 0, and make that
the new default. Applications that need rounded output can set
extra_float_digits back to 0 or below, and take the resulting
performance hit.
We make one concession to portability for systems with buggy
floating-point input: we do not output decimal values that fall
exactly halfway between adjacent representable binary values (which
would rely on the reader doing round-to-nearest-even correctly). This
is known to be a problem at least for VS2013 on Windows.
Our version of the Ryu code originates from
https://github.com/ulfjack/ryu/ at commit c9c3fb1979, but with the
following (significant) modifications:
- Output format is changed to use fixed-point notation for small
exponents, as printf would, and also to use lowercase 'e', a
minimum of 2 exponent digits, and a mandatory sign on the exponent,
to keep the formatting as close as possible to previous output.
- The output of exact midpoint values is disabled as noted above.
- The integer fast-path code is changed somewhat (since we have
fixed-point output and the upstream did not).
- Our project style has been largely applied to the code with the
exception of C99 declaration-after-statement, which has been
retained as an exception to our present policy.
- Most of upstream's debugging and conditionals are removed, and we
use our own configure tests to determine things like uint128
availability.
Changing the float output format obviously affects a number of
regression tests. This patch uses an explicit setting of
extra_float_digits=0 for test output that is not expected to be
exactly reproducible (e.g. due to numerical instability or differing
algorithms for transcendental functions).
Conversions from floats to numeric are unchanged by this patch. These
may appear in index expressions and it is not yet clear whether any
change should be made, so that can be left for another day.
This patch assumes that the only supported floating point format is
now IEEE format, and the documentation is updated to reflect that.
Code by me, adapting the work of Ulf Adams and other contributors.
References:
https://dl.acm.org/citation.cfm?id=3192369
Reviewed-by: Tom Lane, Andres Freund, Donald Dong
Discussion: https://postgr.es/m/87r2el1bx6.fsf@news-spur.riddles.org.uk
Using strtod() creates a double-rounding problem; the input decimal
value is first rounded to the nearest double; rounding that to the
nearest float may then give an incorrect result.
An example is that 7.038531e-26 when input via strtod and then rounded
to float4 gives 0xAE43FEp-107 instead of the correct 0xAE43FDp-107.
Values output by earlier PG versions with extra_float_digits=3 should
all be read in with the same values as previously. However, values
supplied by other software using shortest representations could be
mis-read.
On platforms that lack a strtof() entirely, we fall back to the old
incorrect rounding behavior. (As strtof() is required by C99, such
platforms are considered of primarily historical interest.) On VS2013,
some workarounds are used to get correct error handling.
The regression tests now test for the correct input values, so
platforms that lack strtof() will need resultmap entries. An entry for
HP-UX 10 is included (more may be needed).
Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/871s5emitx.fsf@news-spur.riddles.org.uk
Discussion: https://postgr.es/m/87d0owlqpv.fsf@news-spur.riddles.org.uk
ftoi4 and its sibling coercion functions did their overflow checks in
a way that looked superficially plausible, but actually depended on an
assumption that the MIN and MAX comparison constants can be represented
exactly in the float4 or float8 domain. That fails in ftoi4, ftoi8,
and dtoi8, resulting in a possibility that values near the MAX limit will
be wrongly converted (to negative values) when they need to be rejected.
Also, because we compared before rounding off the fractional part,
the other three functions threw errors for values that really ought
to get rounded to the min or max integer value.
Fix by doing rint() first (requiring an assumption that it handles
NaN and Inf correctly; but dtoi8 and ftoi8 were assuming that already),
and by comparing to values that should coerce to float exactly, namely
INTxx_MIN and -INTxx_MIN. Also remove some random cosmetic discrepancies
between these six functions.
Per bug #15519 from Victor Petrovykh. This should get back-patched,
but first let's see what the buildfarm thinks of it --- I'm not too
sure about portability of some of the regression test cases.
Patch by me; thanks to Andrew Gierth for analysis and discussion.
Discussion: https://postgr.es/m/15519-4fc785b483201ff1@postgresql.org
This reverts commit 55e0e45817.
It's served its purpose of demonstrating what was wrong on
buildfarm member opossum. We could consider putting some kind
of single-purpose hack into ftod() to make the test pass there;
but I don't think it's worth the trouble, since there are surely
many other places whether this platform bug could manifest.
Results from buildfarm member opossum suggest that this doesn't work
quite right on that platform. We've seen issues with NaN support on
MIPS/NetBSD before ... allegedly they fixed this stuff back in 2010,
but maybe only for small values of "fixed".
If, in fact, opossum fails this test then I plan to revert it;
it's mainly for diagnostic purposes rather than something we'd
necessarily keep long-term. I think that the failures in window.sql
could be worked around with some code duplication, but I want to
verify my theory about the cause first.
the fact that NetBSD/mips is currently broken, as per buildfarm member pika.
Also add regression tests to ensure that get_float8_nan and get_float4_nan
are exercised even on platforms where they are not needed by
float8in/float4in.
Zoltán Böszörményi and Tom Lane
valid result from a computation if one of the input values was infinity.
The previous code assumed an operation that returned infinity was an
overflow.
Handle underflow/overflow consistently, and add checks for aggregate
overflow.
Consistently prevent Inf/Nan from being cast to integer data types.
Fix INT_MIN % -1 to prevent overflow.
Update regression results for new error text.
Per report from Roman Kononov.
in UPDATE. We also now issue a NOTICE if a query has _any_ implicit
range table entries -- in the past, we would only warn about implicit
RTEs in SELECTs with at least one explicit RTE.
As a result of the warning change, 25 of the regression tests had to
be updated. I also took the opportunity to remove some bogus whitespace
differences between some of the float4 and float8 variants. I believe
I have correctly updated all the platform-specific variants, but let
me know if that's not the case.
Original patch for DELETE ... USING from Euler Taveira de Oliveira,
reworked by Neil Conway.
types. Update the regression tests and the documentation to reflect
this. Remove the UNSAFE_FLOATS #ifdef.
This is only half the story: we still unconditionally reject
floating point operations that result in +/- infinity. See
recent thread on -hackers for more information.
any amount of leading or trailing whitespace (where "whitespace"
is defined by isspace()). This is for SQL conformance, as well
as consistency with other numeric types (e.g. oid, numeric).
Also refactor pg_atoi() to avoid looking at errno where not
necessary, and add a bunch of regression tests for the input
to these types.
division and modulo functions, to avoid problems on OS X (which fails to
trap 0 divide at all) and Windows (which traps it in some bizarre
nonstandard fashion). Standardize on 'division by zero' as the one true
spelling of this error message. Add regression tests as suggested by
Neil Conway.
the DROP TABLE calls from the destroy.sql file to the 'types' .sql files,
so that they are self-contained
btree_index, hash_index and misc all fail as there seems to be missing
a 'misc.out' expected file...have asked Thomas for one...
Tom Lane
Michael Paquier
Andrew Gierth
Peter Eisentraut
Bruce Momjian
Neil Conway
Thomas G. Lockhart
Marc G. Fournier