sgesvd_bufferSize int32 overflow with CUDA 10.1

After upgrading from CUDA 9.0 to CUDA 10.1, I noticed I’m not able to compute svd on big matrices because of a int32 overflow in sgesvd_bufferSize here: https://github.com/cupy/cupy/blob/master/cupy/linalg/decomposition.py#L257 When bufferSize is just above 2**31 = 2147483648, then sgesvd_bufferSize fails with CUSOLVER_STATUS_INVALID_VALUE, likely because of a wrong cast to negative values. If you continue increasing, you can get positive values again, but wrong ones. See graph below.

This might be an issue with cuSOLVER itself, not cupy, but since I’m not familiar with testing CUDA without cupy I can’t tell. It might be related to #1365 as well, but I haven’t tested on CUDA 9.1 nor 10.0.

import numpy
from cupy.cuda import cusolver
from cupy.cuda import device

handle = device.get_cusolver_handle()

def test(m):
  try:
    return cusolver.sgesvd_bufferSize(handle, m, 1)
  except:
    return numpy.nan
values = [(m, test(m)) for m in numpy.linspace(1, 150000, 200).astype('int')]    

CuPy Version          : 6.2.0
CUDA Build Version    : 10010

[anaruse]

This issue should have been fixed in CUDA 11.0.

[anaruse]

Thanks for your information again. This issue is recognized by the library team now. This issue (requiring much more work space) seems to be a side effect of performance improvement in CUDA 10.1 from old version.