This PR implements `try_solve`: a function that tries to move terms of a relational
expression around, so as to isolate a given variable on the left-hand side.
For example:
```python
>>> try_solve(Eq(a + 5, 3), a)
Eq(a, -2)
>>> try_solve(Gt(Mod(a, 3), 0), a) # returns None
>>> try_solve(Gt(Mod(a, 3), 0), Mod(a, 3))
Gt(Mod(a, 3), 0), Mod(a, 3)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/105877
Approved by: https://github.com/ezyang
This PR:
- Adds `floordiv` and `truncdiv` as they were missing
- Maps `div` to its correct definition (it was being mapped to `floordiv`)
- Simplifies the bounds of `floordiv`
- Fixes some issues with the returned types of `floor` `ceil`
- Adds tests for the previous point
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100547
Approved by: https://github.com/ezyang
This utility allows us to conveniently abstract interpret Sympy expressions with respect to some alternative domain. I am particularly interested in using ValueRanges to do range analysis on expressions (not this PR).
Some minor house-keeping:
* ReferenceAnalysis got moved to its own file, sprouted a constant() implementation, and some uses of math.* got converted to sympy.*
* ValueRangeAnalysis now understands mod
* Test file gets moved from `test_value_ranges.py` to `test_sympy_utils.py`
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/94985
Approved by: https://github.com/eellison
