Fix undefined behavior #2587
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Fix undefined behavior #2587
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This pull request was exported from Phabricator. Differential Revision: D57281091 |
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Summary: For a signed integer type it is undefined behavior in C++ to left-shift bits into the leftmost position where the result would become a negative number. Rewrite several `((long long)1) << X)` expressions to `1ULL << X` using unsigned long long to avoid this undefined behavior fixing UBSan complaints. This rewrites all instances of the pattern for consistency (even in places that wouldn't end up shifting into the highest bit position). Differential Revision: D57281091
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This pull request was exported from Phabricator. Differential Revision: D57281091 |
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This pull request has been merged in 7792908. |
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Summary:
For a signed integer type it is undefined behavior in C++ to left-shift bits into the leftmost position where the result would become a negative number.
Rewrite several
((long long)1) << X)expressions to1ULL << Xusing unsigned long long to avoid this undefined behavior fixing UBSan complaints. This rewrites all instances of the pattern for consistency (even in places that wouldn't end up shifting into the highest bit position).Differential Revision: D57281091