Message98308
| Author |
cmcqueen1975 |
| Recipients |
cmcqueen1975, dtorp, josiahcarlson, mark.dickinson, tim.peters |
| Date |
2010年01月26日.01:06:39 |
| SpamBayes Score |
0.00033885657 |
| Marked as misclassified |
No |
| Message-id |
<1264468002.06.0.0627214993591.issue1205239@psf.upfronthosting.co.za> |
| In-reply-to |
| Content |
Just for the record... here is a relevant use case...
I'm working on some code for calculating CRCs, and hope to support any CRC width, including CRC-5. This involves, among the calculations:
crc >> (crc_width - 8)
The complete expression is:
crc = table[((crc >> (crc_width - 8)) ^ data_byte) & 0xFF] ^ (crc << 8)
where crc_width is typically 32 or 16, but in the case of CRC-5 would be 5.
I think the calculation would work fine for all cases, if only Python allowed me to right-shift with a negative number. But now I'll have to handle the two cases separately. |
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