3 ms·

For python it seems to generate a more reasonable result at least: # Swap the sixth bit and seventeenth bit of a 32-bit signed integer. def swap_bits(x

by asxd 5y ago

For python it seems to generate a more reasonable result at least: # Swap the sixth bit and seventeenth bit of a 32-bit signed integer. def swap_bits(x): # Get the bit at position 6 and 17. bit6 = x & (1 << 6) bit17 = x & (1 << 17) # Swap the bits. x = x ^ (bit6 << 17) x = x ^ (bit17 << 6) return x

37ef_ced3 5y ago
I guess CoPilot has seen bit swapping in its Python training input but not in its Go training input. The Python code is wrong because the 17th bit is shifted up, not down. Also, the bits are shifted by the wrong amount, not up/down by 11 (= 17 minus 6), but up by 6 and up by 17. What a joke. Not only that, even if the shifts were correct, it's simply xoring the bits. The swap is completely wrong. Garbage code, total fail.
- asxd 5y ago
  Yeah, it seems to be pretty heavily trained on Python. It's honestly still (and should be used as) a glorified autocomplete, which is pretty useful from time to time.
stillwrong 5y ago
The function doesn't do the comment says it does. The code to "Swap the bits." just turns the bits on. >>> def swap_bits(x): # Get the bit at position 6 and 17. bit6 = x & (1 << 6) bit17 = x & (1 << 17) # Swap the bits. x = x ^ (bit6 << 17) x = x ^ (bit17 << 6) return x >>> x6 = (1 << 6) >>> f"{x6:b}" '1000000' >>> s6 = swap_bits(x6) >>> f"{s6:b}" '100000000000000001000000' Here's one that correctly swap bits. It could be made more concise. >>> def swap_specific(x,i,j): def get(x,p): return 1 if x & (1 << p) else 0 def set(x,p): return x ^ (1 << p) def clr(x,p): return x & ~(1 << p) bi, bj = get(x,i), get(x,j) x = set(x,j) if bi else clr(x,j) x = set(x,i) if bj else clr(x,i) return x >>> f"{x6:b}" '1000000' >>> b6 = swap_specific(x6,6,17) >>> f"{b6:b}" '100000000000000000'
- xordoh 5y ago
  almost but this part is swrong def set(x,p): return x ^ (1 << p) should probably be def set(x,p): return x | (1 << p)

by asxd 5y ago

37ef_ced3 5y ago

I guess CoPilot has seen bit swapping in its Python training input but not in its Go training input. The Python code is wrong because the 17th bit is shifted up, not down. Also, the bits are shifted by the wrong amount, not up/down by 11 (= 17 minus 6), but up by 6 and up by 17. What a joke. Not only that, even if the shifts were correct, it's simply xoring the bits. The swap is completely wrong. Garbage code, total fail.

asxd 5y ago
Yeah, it seems to be pretty heavily trained on Python. It's honestly still (and should be used as) a glorified autocomplete, which is pretty useful from time to time.

stillwrong 5y ago

The function doesn't do the comment says it does. The code to "Swap the bits." just turns the bits on. >>> def swap_bits(x): # Get the bit at position 6 and 17. bit6 = x & (1 << 6) bit17 = x & (1 << 17) # Swap the bits. x = x ^ (bit6 << 17) x = x ^ (bit17 << 6) return x >>> x6 = (1 << 6) >>> f"{x6:b}" '1000000' >>> s6 = swap_bits(x6) >>> f"{s6:b}" '100000000000000001000000' Here's one that correctly swap bits. It could be made more concise. >>> def swap_specific(x,i,j): def get(x,p): return 1 if x & (1 << p) else 0 def set(x,p): return x ^ (1 << p) def clr(x,p): return x & ~(1 << p) bi, bj = get(x,i), get(x,j) x = set(x,j) if bi else clr(x,j) x = set(x,i) if bj else clr(x,i) return x >>> f"{x6:b}" '1000000' >>> b6 = swap_specific(x6,6,17) >>> f"{b6:b}" '100000000000000000'

xordoh 5y ago
almost but this part is swrong def set(x,p): return x ^ (1 << p) should probably be def set(x,p): return x | (1 << p)