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Description
Describe the issue:
Scalar bitshifts seem not to be implemented and are either upcasting to int64 or failing to upcast (for uint64).
Reproduce the code example:
import numpy as np
dtypes = np.uint16, np.uint32, np.uint64
for dtype in dtypes:
scalar = dtype(15)
array = np.array([15], dtype=dtype)
print("dtype = ", dtype)
print("Scalar right shift: ", end="")
try:
result = scalar >> 1
print(result, type(result))
except:
print("Error")
print("Scalar left shift: ", end="")
try:
result = scalar << 1
print(result, type(result))
except:
print("Error")
print("Array right shift: ", end="")
try:
result = array >> 1
print(result, result.dtype)
except:
print("Error")
print("Array left shift: ", end="")
try:
result = array << 1
print(result, result.dtype)
except:
print("Error")
print()Error message:
❯ python bitshift_dtypes.py
dtype = <class 'numpy.uint16'>
Scalar right shift: 7 <class 'numpy.int64'>
Scalar left shift: 30 <class 'numpy.int64'>
Array right shift: [7] uint16
Array left shift: [30] uint16
dtype = <class 'numpy.uint32'>
Scalar right shift: 7 <class 'numpy.int64'>
Scalar left shift: 30 <class 'numpy.int64'>
Array right shift: [7] uint32
Array left shift: [30] uint32
dtype = <class 'numpy.uint64'>
Scalar right shift: Error
Scalar left shift: Error
Array right shift: [7] uint64
Array left shift: [30] uint64
``NumPy/Python version information:
❯ python -c 'import sys, numpy; print(numpy.version, sys.version)'
1.21.5 3.10.2 (main, Jan 15 2022, 19:56:27) [GCC 11.1.0]