Repository navigation
Fix stack overflow in ratpowi32 when power is INT32_MIN - #2512
Open
Amit Dey (amitdey1987) wants to merge 2 commits into
Open
Amit Dey (amitdey1987) wants to merge 2 commits into
Amit Dey (amitdey1987) wants to merge 2 commits into
Conversation
ratpowi32 handled negative powers by recursing with -power. For INT32_MIN the negation overflows back to INT32_MIN, so the function recursed until the stack was exhausted, crashing on input such as (-1)^(-2^31). Compute the magnitude of the power as uint32_t, run the square-and-multiply loop on that, and invert the result afterwards for negative powers. This also removes the recursion. Fixes microsoft#2500 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Author
|
@microsoft-github-policy-service agree |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
ratpowi32 handled negative powers by recursing with -power. For INT32_MIN the negation overflows back to INT32_MIN, so the function recursed until the stack was exhausted, crashing on input such as (-1)^(-2^31).
Fixes #2500.
Description of the changes:
Compute the magnitude of the power as uint32_t, run the square-and-multiply loop on that, and invert the result afterwards for negative powers. This also removes the recursion.
How changes were validated: