Make heap large chunk bit twiddling branchless #4526
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We use some bit twiddling operations for setting some flags on large chunks in actor heaps. Before this commit, the functionality was implemented with a ternary operator which would result in a branch. This commit changes the logic to use bit shifts instead to avoid the branching.
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jemc
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This is good, but can you please move the three shift amounts (2, 3, 4, respectively) into #define preprocessor macros instead of inline integer literals here?
And then can you also refactor the definition of the three _BITMASK macros to rely on those shift amount macros?
That should make this change more robust to other changes across time.
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jemc
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We use some bit twiddling operations for setting some flags on large chunks in actor heaps. Before this commit, the functionality was implemented with a ternary operator which would result in a branch.
This commit changes the logic to use bit shifts instead to avoid the branching.