| Type | Bug | Status | built | Date | 14-Jul-2010 23:19 |
|---|---|---|---|---|---|
| Version | alpha 58 | Category | Native | Submitted by | abolka |
| Platform | Linux x86 libc6 | Severity | minor | Priority | normal |
| Summary | Fix inconsistency of mold/all of decimals between Linux x86 and OSX/Win32 |
|---|---|
| Description |
(Originally "mold/all 0.1 on Windows and Linux produces a different result". Updated to reflect the comments.) The results of mold/all for decimals on Linux is inconsistent with other platforms (Win32, OSX): >> mold/all 0.3 == "0.3" ; expected: "0.29999999999999999" >> mold/all 0.1 == "0.1" ; expected: "0.10000000000000001" Basically this is #897 re-opened as it was never really fixed on Linux. See the comments for a suggested fix by Ladislav. |
| Example code |
| Assigned to | n/a | Fixed in | r3 master | Last Update | 21-Jan-2013 06:56 |
|---|
| Comments | |
|---|---|
|
(0002445)
Carl 15-Jul-2010 00:02 |
We work to try to avoid issues like that, but it is not easy because there are subtle differences in the implementation of the standard C math lib between platforms, and also the availability and definition of fundamental lower level lib functions (like gcvt()). Such things will pop up, and we need to fix them. |
|
(0002881)
PeterWood 16-Nov-2010 00:54 |
Also on OS X
>> system/version == 2.100.109.2.5 >> mold/all 0.1 == "0.10000000000000001" |
|
(0002884)
Ladislav 17-Nov-2010 11:47 |
The expression result is obtained as a result of two operations:
*the first one is LOAD function transforming the "0.1" part of the input string to a 64-bit binary IEEE754 number used as the internal representation of REBOL decimals. In accordance with the standard, the result of this operation is exactly 0.1000000000000000055511151231257827021181583404541015625 *the second operation is MOLD/ALL, transforming the above number to string. Both "0.1" as well as "0.10000000000000001" are results that are accurate enough from the POV that the expressions zero? 0.1 - load string same? 0.1 load string both yield TRUE. The difference is that the Windows ECVT version yields the string containing exactly 17 digits of the floating point number while the Linux version of ECVT yields the minimal string that represents the number accurately enough, i.e., in such a way that the two tests mentioned above both yield TRUE. |
|
(0002887)
Ladislav 18-Nov-2010 08:20 |
In the core-tests suite. (the core-tests suite currently tests the accuracy of the MOLD/ALL result)
To obtain the same string on all platforms it probably is best to use the code available, e.g., from https://github.com/android/platform_bionic/blob/master/libc/stdlib/strtod.c , on the platforms offering only a less convenient alternative of the behaviour. |
|
(0003124)
abolka 22-Feb-2011 01:02 |
Still not fixed in A111:
>> system/version == 2.100.111.4.4 >> mold/all 0.3 == "0.3" >> mold/all 0.1 == "0.1" |
|
(0003129)
abolka 26-Feb-2011 16:18 |
HAS_ECVT is still defined (for TO_LINUX) in the hostkit sources. |
|
(0003261)
abolka 13-Dec-2012 02:26 |
*Not* fixed in the 101.0 (08eb7e84cd) open source release.
HAS_ECVT is still defined. Undefining it, fixes the immediate issue while not introducing any regression in the rebol-test suite. |
|
(0003264)
abolka 14-Dec-2012 01:54 |
(I submitted removing HAS_ECVT as https://github.com/rebol/r3/pull/4.)
Unfortunately, without HAS_ECVT `mold/all 0.1` works as expected, this comes at the expense of a regression. Without `HAS_ECVT` the following fails in Linux builds: same? 9.9999999999999926e154% load mold/all 9.9999999999999926e154% Whereas with `HAS_ECVT` for Linux the above is true as it already is on Win32, OSX. |
|
(0003272)
abolka 17-Dec-2012 00:27 |
Works with Carl's merge in b064f51eb180ff50e74ba815d780001fc2120694. |
|
(0003387)
Ladislav 21-Jan-2013 03:12 |
This is a related but separate issue than #897. Also, we need to have a more general solution working for R3/Droid and Linux/ARM, not just for Linux/X86, I will open a new ticket for those. |
| Date | User | Field | Action | Change |
|---|---|---|---|---|
| 21-Jan-2013 06:56 | abolka | Summary | Modified | Fix string output inconsistency of mold/all of decimals on Linux x86 => Fix inconsistency of mold/all of decimals between Linux x86 and OSX/Win32 |
| 21-Jan-2013 03:15 | Ladislav | Comment : 0003387 | Modified | - |
| 21-Jan-2013 03:14 | Ladislav | Comment : 0003387 | Modified | - |
| 21-Jan-2013 03:12 | Ladislav | Comment : 0003387 | Added | - |
| 21-Jan-2013 03:10 | Ladislav | Comment : 0002884 | Modified | - |
| 21-Jan-2013 03:09 | Ladislav | Comment : 0002884 | Modified | - |
| 20-Jan-2013 03:29 | abolka | Status | Modified | complete => built |
| 20-Jan-2013 03:28 | abolka | Fixedin | Modified | 2.101.0 => r3 master |
| 20-Jan-2013 02:12 | abolka | Summary | Modified | Fix cross-platform inconsistency of mold/all of decimals on Linux x86 => Fix string output inconsistency of mold/all of decimals on Linux x86 |
| 20-Jan-2013 02:10 | abolka | Summary | Modified | Fix mold/all of decimals on Linux => Fix cross-platform inconsistency of mold/all of decimals on Linux x86 |
| 20-Jan-2013 01:49 | Ladislav | Comment : 0003271 | Removed | - |
| 20-Jan-2013 01:47 | Ladislav | Comment : 0003128 | Removed | - |
| 20-Jan-2013 01:47 | Ladislav | Comment : 0002887 | Modified | - |
| 20-Jan-2013 01:46 | Ladislav | Comment : 0002887 | Modified | - |
| 20-Jan-2013 01:33 | Ladislav | Comment : 0002885 | Removed | - |
| 20-Jan-2013 01:32 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Dec-2012 00:28 | abolka | Status | Modified | submitted => complete |
| 17-Dec-2012 00:28 | abolka | Fixedin | Modified | => 2.101.0 |
| 17-Dec-2012 00:27 | abolka | Comment : 0003272 | Added | - |
| 16-Dec-2012 23:33 | Ladislav | Comment : 0003271 | Added | - |
| 14-Dec-2012 01:54 | abolka | Comment : 0003264 | Added | - |
| 13-Dec-2012 02:26 | abolka | Comment : 0003261 | Added | - |
| 26-Feb-2011 16:18 | abolka | Comment : 0003129 | Added | - |
| 26-Feb-2011 14:23 | Ladislav | Comment : 0003128 | Added | - |
| 23-Feb-2011 23:53 | BrianH | Category | Modified | Unspecified => Native |
| 22-Feb-2011 05:54 | abolka | Status | Modified | complete => submitted |
| 22-Feb-2011 05:54 | abolka | Fixedin | Modified | alpha 111 => none |
| 22-Feb-2011 05:54 | abolka | Comment : 0003124 | Modified | - |
| 22-Feb-2011 01:02 | abolka | Status | Modified | built => complete |
| 22-Feb-2011 01:02 | abolka | Comment : 0003124 | Added | - |
| 21-Nov-2010 20:43 | carl | Status | Modified | pending => built |
| 21-Nov-2010 20:43 | carl | Fixedin | Modified | => alpha 111 |
| 18-Nov-2010 08:20 | Ladislav | Comment : 0002887 | Added | - |
| 17-Nov-2010 23:22 | abolka | Summary | Modified | Properly mold/all decimals on Linux => Fix mold/all of decimals on Linux |
| 17-Nov-2010 23:20 | abolka | Platform | Modified | All => Linux x86 libc6 |
| 17-Nov-2010 23:20 | abolka | Status | Modified | reviewed => pending |
| 17-Nov-2010 23:20 | abolka | Version | Modified | alpha 99 => alpha 58 |
| 17-Nov-2010 23:20 | abolka | Description | Modified | - |
| 17-Nov-2010 23:20 | abolka | Summary | Modified | mold/all 0.1 on Windows and Linux produces a different result => Properly mold/all decimals on Linux |
| 17-Nov-2010 21:15 | Ladislav | Comment : 0002885 | Modified | - |
| 17-Nov-2010 21:13 | Ladislav | Comment : 0002885 | Added | - |
| 17-Nov-2010 14:11 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 14:00 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 13:59 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:17 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:16 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:12 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:11 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:10 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:09 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:08 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:05 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:04 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:02 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:00 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 12:00 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 11:56 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 11:52 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 11:51 | Ladislav | Comment : 0002884 | Modified | - |
| 17-Nov-2010 11:47 | Ladislav | Comment : 0002884 | Added | - |
| 16-Nov-2010 00:54 | PeterWood | Comment : 0002881 | Added | - |
| 15-Jul-2010 00:02 | carl | Comment : 0002445 | Added | - |
| 14-Jul-2010 23:59 | carl | Status | Modified | submitted => reviewed |
| 14-Jul-2010 23:59 | carl | Description | Modified | - |
| 14-Jul-2010 23:19 | abolka | Ticket | Added | - |