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Created on 2011-01-17 13:00 by mark.dickinson, last changed 2022-04-11 14:57 by admin. This issue is now closed.
| Files | ||||
|---|---|---|---|---|
| File name | Uploaded | Description | Edit | |
| pure_python_long_to_float.patch | mark.dickinson, 2011-01-17 13:00 | review | ||
| pure_python_long_to_float_v2.patch | mark.dickinson, 2011-10-22 18:55 | review | ||
| Messages (4) | |||
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| msg126398 - (view) | Author: Mark Dickinson (mark.dickinson) *  |
Date: 2011-01-17 13:00 | |
It would be helpful (perhaps to developers of alternative implementations) to give a pure Python version of correctly-rounded long-to-float conversion. Attached is such a version, as a patch to test_long in the release27-maint branch. |
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| msg126794 - (view) | Author: Terry J. Reedy (terry.reedy) * |
Date: 2011-01-21 23:28 | |
I see there is already something similar for true division. I find + q_max, shift_max = 1 << sig_bits, sys.float_info.max_exp - sig_bits easier to read as two lines + q_max = 1 << sig_bits + shift_max = sys.float_info.max_exp - sig_bits Not having precedence memorized, I prefer added parens here: + ... (n >> shift) | bool(n & (1 << shift) - 1) I presume that for normal production testing, you would comment out + float = long_to_float |
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| msg146177 - (view) | Author: Mark Dickinson (mark.dickinson) * |
Date: 2011-10-22 18:55 | |
Thanks for the comments. Here's an updated patch, that actually makes use of the pure Python version to test the built-in int-to-float conversion. |
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| msg146247 - (view) | Author: Roundup Robot (python-dev)  |
Date: 2011-10-23 19:07 | |
New changeset 117d51d3dd7d by Mark Dickinson in branch 'default': Issue #10925: Add equivalent pure Python code for the builtin int-to-float conversion to test_long. http://hg.python.org/cpython/rev/117d51d3dd7d |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2022-04-11 14:57:11 | admin | set | github: 55134 |
| 2011-10-23 19:08:13 | mark.dickinson | set | status: open -> closed resolution: fixed stage: resolved |
| 2011-10-23 19:07:54 | python-dev | set | nosy:
+ python-dev messages: + msg146247 |
| 2011-10-22 18:55:07 | mark.dickinson | set | files:
+ pure_python_long_to_float_v2.patch messages: + msg146177 versions: - Python 2.7, Python 3.2 |
| 2011-01-21 23:28:46 | terry.reedy | set | nosy:
+ terry.reedy messages: + msg126794 |
| 2011-01-17 13:01:07 | mark.dickinson | set | type: enhancement components: + Tests |
| 2011-01-17 13:00:41 | mark.dickinson | create | |