This is the release note of v10.0.0a2. See here for the complete list of solved issues and merged PRs.

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Highlights

• CuPy now supports CUDA 11.3 (cupy-cuda113) and AMD ROCm 4.2 (cupy-rocm-4-2) and binary wheels are now available on PyPI.
• The following Python syntax and new APIs can now be used in JIT target functions.
  • Calling len, min, max Python built-ins.
    • len(arr): Equivalent to arr.shape[0].
    • min(scalar1, scalar2, ...): Returns the minimum value of the inputs.
    • max(scalar1, scalar2, ...): Returns the maximum value of the inputs.
  • Accessing .ndim, .size attributes of ndarray.
  • Unpacking nested tuples.
    • (x, y), z = ...
  • jit.grid() API, similar to numba.cuda.grid.
    • x, y, z = cupyx.jit.grid(3) (x is equal to threadIdx.x + blockIdx.x * blockDim.x.)
  • Warp shuffle and sync functions.
    • cupyx.jit.shfl_down_sync(mask, var, val_id) (__shfl_down_sync(mask, var, val_id))
• cupyx.scipy.sparse.{coo,csr,csc}_matrix now provides the reshape method.

Changes without compatibility

Drop CUDA 9.2 & NCCL 2.4 Support (#5214)

CUDA 9.2 and NCCL 2.4 are no longer supported in CuPy v10.

Changes in Stream behavior (#5251)

The same cupy.cuda.Stream instance can now safely be shared between multiple threads. To achieve this, CuPy v10 will not destroy the stream (i.e., call cudaStreamDestroy) if the stream is the current stream of any thread.

Known Issues

• cupy-cuda111 wheels only support CUDA 11.1.1 and will not work with CUDA 11.1.0 (#5313).
• cupy-cuda110 and cupy-cuda111 wheels are not available yet in PyPI. In the meantime, they can be downloaded from the Assets section below. See #4971 for detailed instructions.

Changes

New Features

• Add reshape method for COO, CSR and CSC matrices (#5301)
• Support len, min, max, .ndim, .size in jit (#5319)
• Support nested tuple unpack in CuPy JIT (#5332)
• Support Numba-like jit.grid() syntax in CuPy JIT (#5334)
• Support warp shuffle and sync functions in CuPy JIT (#5335)

Enhancements

• Do not use handles unless requested in cupy.show_config() (#5073)
• Fix to allow sharing a Stream instance between threads (#5251)
• Adding GUFunc order, dtype and casting kwarg support (#5260)
• Support nan, posinf, neginf in cupy.nan_to_num (#5295)
• Use independent version of hipFFT for ROCm 4.1 and later (#5318)
• Support cuTENSOR v1.3.1 (#5338)
• Support cuDNN v8.2.1 (#5357)

Performance Improvements

• Make cuTENSOR available in cupy.einsum (#5203)

Bug Fixes

• Fix check_availablity for cupy.cusolver (#5207)
• Fix MemoryAsync to keep a weakref to stream (#5264)
• Fix cuFFT callback for sm_61 etc (#5304)
• Fix cuDNN preloading (#5327)
• Fix large arrays assignment (#5330)
• Ensure source array is C-contiguous before copying to CUDAArray (#5342)
• Increase test coverage for Generalized Universal Functions (#5344)
• Remove unnecessary print (#5374)

Code Fixes

• Fix cub repository url (#5236)
• Code and comment fixes for stream (#5243)
• Use cdef instead of cpdef where appropriate (#5274)

Documentation

• Fix matmul docstring (#5174)
• Update list of wheels in README (#5267)
• Add user guide for FFT (#5272)
• Bump CuPy version in docs (#5277)
• Add user guide for streams & events (#5283)
• Fix deadlink to tutorial and reorder in README (#5287)
• Document ExternalStream (#5305)
• Add ROCm 4.2 support to install docs (#5354)
• user_guide/basic.rst: various improvements (#5356)

Installation

• Drop support for CUDA 9.2 & NCCL 2.4 (#5214)
• Add upper restrictions to NumPy/SciPy versions (#5225)
• Exclude Cython 3 from setup_requires (#5273)

Tests

• Fix threading memory pool tests (#5263)
• Temporarily remove the async pool test from TestAllocator (#5308)
• Fix Windows CI kernel cache (#5310)
• Tentatively skip unstable MemoryPoolAsync tests (#5350)
• Xfail random generator tests for HIP (#5355)
• Tentatively pin to SciPy 1.6 in Windows CI (#5366)

Contributors

The CuPy Team would like to thank all those who contributed to this release!

@anaruse @eternalphane @leofang @maxim-belkin @povinsahu1909