[mypyc] Replace integer floor division by a power of two with a shift #12870
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msullivan
approved these changes
May 26, 2022
mypyc/irbuild/expression.py
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| if not isinstance(expr.right, IntExpr): | ||
| return expr | ||
| divisor = expr.right.value | ||
| n = 2 |
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This isn't super important, but I think it would be cleaner (and faster, though that doesn't really matter) to directly compute the shift instead of testing for it? I think you can do shift = divisor.bit_length() - 1 and then check that the shift is correct
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Done. We don't have a primitive for bit_length() so it may actually be slower, but I think that the code looks cleaner if we use it.
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In a microbenchmark right shift was a bit faster.