| """Misc integer tools.""" | |
| from __future__ import print_function, absolute_import, division | |
| from fontTools.misc.py23 import * | |
| __all__ = ['popCount'] | |
| def popCount(v): | |
| """Return number of 1 bits in an integer.""" | |
| if v > 0xFFFFFFFF: | |
| return popCount(v >> 32) + popCount(v & 0xFFFFFFFF) | |
| # HACKMEM 169 | |
| y = (v >> 1) & 0xDB6DB6DB | |
| y = v - y - ((y >> 1) & 0xDB6DB6DB) | |
| return (((y + (y >> 3)) & 0xC71C71C7) % 0x3F) |