simplify max(1,x) to x when x known >=1#157189
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laithsakka wants to merge 4 commits intogh/laithsakka/233/basefrom
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simplify max(1,x) to x when x known >=1#157189laithsakka wants to merge 4 commits intogh/laithsakka/233/basefrom
laithsakka wants to merge 4 commits intogh/laithsakka/233/basefrom
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[ghstack-poisoned]
🔗 Helpful Links🧪 See artifacts and rendered test results at hud.pytorch.org/pr/157189
Note: Links to docs will display an error until the docs builds have been completed. ✅ You can merge normally! (1 Unrelated Failure)As of commit 8b30dd2 with merge base feea575 ( UNSTABLE - The following job is marked as unstable, possibly due to flakiness on trunk:
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Creating contiguous strides creates an expression max(1, x). Often we know that x >= 1, in which case we should simplify max(1, x) to x. This appeared in two situations: 1) An internal user complained about statically_known_true(x == max(1, x)) failing (internal link: https://fb.workplace.com/groups/1028545332188949/permalink/1232958568414290). This #155938 won't be needed with this. 3) Not simplifying the above could result in wrong ConstraintViolationErrors. Because we assume non-trival single arg guards shall evaporate see the logic at this line with this change we longer throw ConstraintViolationErrors with the program bellow this is blocking landing this [PR](#155590) from landing internally. Due to internal export tests throwing ConstraintViolationErrors. ``` x = torch.rand(10) torch._dynamo.mark_dynamic(x, 0, max=20, min=5) torch.compile(fullgraph=True, dynamic=True) def func(x): if max(1, (-1 + x.size()[0]//2)) == (-1+x.size()[0]//2): return x*400 else: return (x*10)*100 func(x) ``` [ghstack-poisoned]
pianpwk
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change makes sense, approving to avoid revert. let's generalize this better later?
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Stack from ghstack (oldest at bottom):
Creating contiguous strides creates an expression max(1, x). Often we know that x >= 1, in
which case we should simplify max(1, x) to x.
This appeared in two situations:
An internal user complained about statically_known_true(x == max(1, x)) failing (internal link: https://fb.workplace.com/groups/1028545332188949/permalink/1232958568414290).
This Fix stride comparison max(512 - s, 1) vs. (512 - s) #155938 won't be needed with this.
Not simplifying the above could result in wrong ConstraintViolationErrors.
Because we assume non-trival single arg guards shall evaporate see the logic in the function
issue_guard in symbolic_shapes.py
with this change we longer throw ConstraintViolationErrors with the program bellow
this is blocking landing this PR from landing
internally. Due to internal export tests throwing ConstraintViolationErrors.
like
cc @ezyang @SherlockNoMad @EikanWang @jgong5 @wenzhe-nrv