Add cuTENSOR support & bug fixes discovered while working on conda testing

cuda_pathfinder/cuda/pathfinder/__init__.py

@@ -13,7 +13,7 @@
 from cuda.pathfinder._headers.supported_nvidia_headers import SUPPORTED_HEADERS_CTK as _SUPPORTED_HEADERS_CTK
 from cuda.pathfinder._version import __version__ as __version__
 
-# Indirection to help Sphinx find the docstring.
+# Indirections to help Sphinx find the docstrings.
 #: Mapping from short CUDA Toolkit (CTK) library names to their canonical
 #: header basenames (used to validate a discovered include directory).
 #: Example: ``"cublas" → "cublas.h"``. The key set is platform-aware

cuda_pathfinder/cuda/pathfinder/_dynamic_libs/supported_nvidia_libs.py

@@ -82,8 +82,11 @@
 }
 DIRECT_DEPENDENCIES = DIRECT_DEPENDENCIES_CTK | {
  "mathdx": ("nvrtc",),
+ "cublasmp": ("cublas", "cublasLt", "nvshmem_host"),
  "cufftMp": ("nvshmem_host",),
  "cudss": ("cublas", "cublasLt"),
+ "cutensor": ("cublasLt",),
+ "cutensorMg": ("cutensor", "cublasLt"),
 }
 
 # Based on these released files:
@@ -238,9 +241,11 @@
 }
 SUPPORTED_LINUX_SONAMES_OTHER = {
  "cublasmp": ("libcublasmp.so.0",),
- "cufftMp": ("libcufftMp.so.11",),
+ "cufftMp": ("libcufftMp.so.12", "libcufftMp.so.11"),
  "mathdx": ("libmathdx.so.0",),
  "cudss": ("libcudss.so.0",),
+ "cutensor": ("libcutensor.so.2",),
+ "cutensorMg": ("libcutensorMg.so.2",),
  "nccl": ("libnccl.so.2",),
  "nvpl_fftw": ("libnvpl_fftw.so.0",),
  "nvshmem_host": ("libnvshmem_host.so.3",),
@@ -402,6 +407,8 @@
 SUPPORTED_WINDOWS_DLLS_OTHER = {
  "mathdx": ("mathdx64_0.dll",),
  "cudss": ("cudss64_0.dll",),
+ "cutensor": ("cutensor.dll",),
+ "cutensorMg": ("cutensorMg.dll",),
 }
 SUPPORTED_WINDOWS_DLLS = SUPPORTED_WINDOWS_DLLS_CTK | SUPPORTED_WINDOWS_DLLS_OTHER
 
@@ -446,7 +453,9 @@
 SITE_PACKAGES_LIBDIRS_LINUX_OTHER = {
  "cublasmp": ("nvidia/cublasmp/cu13/lib", "nvidia/cublasmp/cu12/lib"),
  "cudss": ("nvidia/cu13/lib", "nvidia/cu12/lib"),
- "cufftMp": ("nvidia/cufftmp/cu12/lib",),
+ "cufftMp": ("nvidia/cufftmp/cu13/lib", "nvidia/cufftmp/cu12/lib"),
+ "cutensor": ("cutensor/lib",),
+ "cutensorMg": ("cutensor/lib",),
  "mathdx": ("nvidia/cu13/lib", "nvidia/cu12/lib"),
  "nccl": ("nvidia/nccl/lib",),
  "nvpl_fftw": ("nvpl/lib",),
@@ -484,7 +493,10 @@
  "nvvm": ("nvidia/cu13/bin/x86_64", "nvidia/cuda_nvcc/nvvm/bin"),
 }
 SITE_PACKAGES_LIBDIRS_WINDOWS_OTHER = {
+ "cudss": ("nvidia/cu13/bin", "nvidia/cu12/bin"),
  "mathdx": ("nvidia/cu13/bin/x86_64", "nvidia/cu12/bin"),
+ "cutensor": ("cutensor/bin",),
+ "cutensorMg": ("cutensor/bin",),
 }
 SITE_PACKAGES_LIBDIRS_WINDOWS = SITE_PACKAGES_LIBDIRS_WINDOWS_CTK | SITE_PACKAGES_LIBDIRS_WINDOWS_OTHER
 

cuda_pathfinder/cuda/pathfinder/_headers/find_nvidia_headers.py

@@ -22,28 +22,12 @@ def _joined_isfile(dirpath: str, basename: str) -> bool:
  return os.path.isfile(os.path.join(dirpath, basename))
 
 
-def _find_nvshmem_header_directory() -> Optional[str]:
- if IS_WINDOWS:
- # nvshmem has no Windows support.
- return None
-
+def _find_under_site_packages(sub_dir: str, h_basename: str) -> Optional[str]:
  # Installed from a wheel
- nvidia_sub_dirs = ("nvidia", "nvshmem", "include")
  hdr_dir: str # help mypy
- for hdr_dir in find_sub_dirs_all_sitepackages(nvidia_sub_dirs):
- if _joined_isfile(hdr_dir, "nvshmem.h"):
- return hdr_dir
-
- conda_prefix = os.environ.get("CONDA_PREFIX")
- if conda_prefix and os.path.isdir(conda_prefix):
- hdr_dir = os.path.join(conda_prefix, "include")
- if _joined_isfile(hdr_dir, "nvshmem.h"):
- return hdr_dir
-
- for hdr_dir in sorted(glob.glob("/usr/include/nvshmem_*"), reverse=True):
- if _joined_isfile(hdr_dir, "nvshmem.h"):
+ for hdr_dir in find_sub_dirs_all_sitepackages(tuple(sub_dir.split("/"))):
+ if _joined_isfile(hdr_dir, h_basename):
  return hdr_dir
-
  return None
 
 
@@ -54,6 +38,13 @@ def _find_based_on_ctk_layout(libname: str, h_basename: str, anchor_point: str)
  parts.append("include")
  idir = os.path.join(*parts)
  if libname == "cccl":
+ if IS_WINDOWS:
+ cdir_ctk12 = os.path.join(idir, "targets", "x64") # conda has this anomaly
+ cdir_ctk13 = os.path.join(cdir_ctk12, "cccl")
+ if _joined_isfile(cdir_ctk13, h_basename):
+ return cdir_ctk13
+ if _joined_isfile(cdir_ctk12, h_basename):
+ return cdir_ctk12
  cdir = os.path.join(idir, "cccl") # CTK 13
  if _joined_isfile(cdir, h_basename):
  return cdir
@@ -62,38 +53,40 @@ def _find_based_on_ctk_layout(libname: str, h_basename: str, anchor_point: str)
  return None
 
 
-def _find_based_on_conda_layout(libname: str, h_basename: str, conda_prefix: str) -> Optional[str]:
+def _find_based_on_conda_layout(libname: str, h_basename: str, ctk_layout: bool) -> Optional[str]:
+ conda_prefix = os.environ.get("CONDA_PREFIX")
+ if not conda_prefix:
+ return None
  if IS_WINDOWS:
  anchor_point = os.path.join(conda_prefix, "Library")
  if not os.path.isdir(anchor_point):
  return None
  else:
- targets_include_path = glob.glob(os.path.join(conda_prefix, "targets", "*", "include"))
- if not targets_include_path:
- return None
- if len(targets_include_path) != 1:
- # Conda does not support multiple architectures.
- # QUESTION(PR#956): Do we want to issue a warning?
- return None
- anchor_point = os.path.dirname(targets_include_path[0])
+ if ctk_layout:
+ targets_include_path = glob.glob(os.path.join(conda_prefix, "targets", "*", "include"))
+ if not targets_include_path:
+ return None
+ if len(targets_include_path) != 1:
+ # Conda does not support multiple architectures.
+ # QUESTION(PR#956): Do we want to issue a warning?
+ return None
+ include_path = targets_include_path[0]
+ else:
+ include_path = os.path.join(conda_prefix, "include")
+ anchor_point = os.path.dirname(include_path)
  return _find_based_on_ctk_layout(libname, h_basename, anchor_point)
 
 
 def _find_ctk_header_directory(libname: str) -> Optional[str]:
  h_basename = supported_nvidia_headers.SUPPORTED_HEADERS_CTK[libname]
  candidate_dirs = supported_nvidia_headers.SUPPORTED_SITE_PACKAGE_HEADER_DIRS_CTK[libname]
 
- # Installed from a wheel
  for cdir in candidate_dirs:
- hdr_dir: str # help mypy
- for hdr_dir in find_sub_dirs_all_sitepackages(tuple(cdir.split("/"))):
- if _joined_isfile(hdr_dir, h_basename):
- return hdr_dir
+ if hdr_dir := _find_under_site_packages(cdir, h_basename):
+ return hdr_dir
 
- conda_prefix = os.environ.get("CONDA_PREFIX")
- if conda_prefix: # noqa: SIM102
- if result := _find_based_on_conda_layout(libname, h_basename, conda_prefix):
- return result
+ if hdr_dir := _find_based_on_conda_layout(libname, h_basename, True):
+ return hdr_dir
 
  cuda_home = get_cuda_home_or_path()
  if cuda_home: # noqa: SIM102
@@ -132,19 +125,28 @@ def find_nvidia_header_directory(libname: str) -> Optional[str]:
  3. **CUDA Toolkit environment variables**
 
  - Use ``CUDA_HOME`` or ``CUDA_PATH`` (in that order).
-
- Notes:
- - The ``SUPPORTED_HEADERS_CTK`` dictionary maps each supported CUDA Toolkit
- (CTK) library to the name of its canonical header (e.g., ``"cublas" →
- "cublas.h"``). This is used to verify that the located directory is valid.
-
- - The only supported non-CTK library at present is ``nvshmem``.
  """
 
- if libname == "nvshmem":
- return _abs_norm(_find_nvshmem_header_directory())
-
  if libname in supported_nvidia_headers.SUPPORTED_HEADERS_CTK:
  return _abs_norm(_find_ctk_header_directory(libname))
 
- raise RuntimeError(f"UNKNOWN {libname=}")
+ h_basename = supported_nvidia_headers.SUPPORTED_HEADERS_NON_CTK.get(libname)
+ if h_basename is None:
+ raise RuntimeError(f"UNKNOWN {libname=}")
+
+ candidate_dirs = supported_nvidia_headers.SUPPORTED_SITE_PACKAGE_HEADER_DIRS_NON_CTK.get(libname, [])
+ hdr_dir: Optional[str] # help mypy
+ for cdir in candidate_dirs:
+ if hdr_dir := _find_under_site_packages(cdir, h_basename):
+ return _abs_norm(hdr_dir)
+
+ if hdr_dir := _find_based_on_conda_layout(libname, h_basename, False):
+ return _abs_norm(hdr_dir)
+
+ candidate_dirs = supported_nvidia_headers.SUPPORTED_INSTALL_DIRS_NON_CTK.get(libname, [])
+ for cdir in candidate_dirs:
+ for hdr_dir in sorted(glob.glob(cdir), reverse=True):
+ if _joined_isfile(hdr_dir, h_basename):
+ return _abs_norm(hdr_dir)
+
+ return None

cuda_pathfinder/cuda/pathfinder/_headers/supported_nvidia_headers.py

@@ -57,3 +57,28 @@
  "nvrtc": ("nvidia/cu13/include", "nvidia/cuda_nvrtc/include"),
  "nvvm": ("nvidia/cu13/include", "nvidia/cuda_nvcc/nvvm/include"),
 }
+
+SUPPORTED_HEADERS_NON_CTK_COMMON = {
+ "cutensor": "cutensor.h",
+}
+SUPPORTED_HEADERS_NON_CTK_LINUX_ONLY = {
+ "nvshmem": "nvshmem.h",
+}
+SUPPORTED_HEADERS_NON_CTK_WINDOWS_ONLY: Final[dict[str, str]] = {}
+SUPPORTED_HEADERS_NON_CTK_LINUX = SUPPORTED_HEADERS_NON_CTK_COMMON | SUPPORTED_HEADERS_NON_CTK_LINUX_ONLY
+SUPPORTED_HEADERS_NON_CTK_WINDOWS = SUPPORTED_HEADERS_NON_CTK_COMMON | SUPPORTED_HEADERS_NON_CTK_WINDOWS_ONLY
+SUPPORTED_HEADERS_NON_CTK_ALL = (
+ SUPPORTED_HEADERS_NON_CTK_COMMON | SUPPORTED_HEADERS_NON_CTK_LINUX_ONLY | SUPPORTED_HEADERS_NON_CTK_WINDOWS_ONLY
+)
+SUPPORTED_HEADERS_NON_CTK: Final[dict[str, str]] = (
+ SUPPORTED_HEADERS_NON_CTK_WINDOWS if IS_WINDOWS else SUPPORTED_HEADERS_NON_CTK_LINUX
+)
+
+SUPPORTED_SITE_PACKAGE_HEADER_DIRS_NON_CTK = {
+ "cutensor": ("cutensor/include",),
+ "nvshmem": ("nvidia/nvshmem/include",),
+}
+
+SUPPORTED_INSTALL_DIRS_NON_CTK = {
+ "nvshmem": ("/usr/include/nvshmem_*",),
+}

cuda_pathfinder/cuda/pathfinder/_version.py

@@ -1,4 +1,4 @@
 # SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-__version__ = "1.3.1"
+__version__ = "1.3.2"

cuda_pathfinder/docs/nv-versions.json

@@ -3,6 +3,10 @@
  "version": "latest",
  "url": "https://nvidia.github.io/cuda-python/cuda-pathfinder/latest/"
  },
+ {
+ "version": "1.3.2",
+ "url": "https://nvidia.github.io/cuda-python/cuda-pathfinder/1.3.2/"
+ },
  {
  "version": "1.3.1",
  "url": "https://nvidia.github.io/cuda-python/cuda-pathfinder/1.3.1/"

cuda_pathfinder/docs/source/api.rst

@@ -18,4 +18,5 @@ and experimental APIs for locating NVIDIA C/C++ header directories.
  DynamicLibNotFoundError
 
  SUPPORTED_HEADERS_CTK
+ SUPPORTED_HEADERS_NON_CTK
  find_nvidia_header_directory

cuda_pathfinder/docs/source/release/1.3.2-notes.rst

@@ -0,0 +1,15 @@
+.. SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+.. SPDX-License-Identifier: Apache-2.0
+
+.. py:currentmodule:: cuda.pathfinder
+
+``cuda-pathfinder`` 1.3.2 Release notes
+=======================================
+
+Released on Oct 29, 2025
+
+Highlights
+----------
+
+* Add cuTENSOR support & bug fixes discovered while working on conda testing
+ (`PR #1194 <https://github.com/NVIDIA/cuda-python/pull/1194>`_)

cuda_pathfinder/pyproject.toml

@@ -18,6 +18,7 @@ test = [
 cu12 = [
  "cuda-toolkit[nvcc,cublas,nvrtc,cudart,cufft,curand,cusolver,cusparse,npp,nvfatbin,nvjitlink,nvjpeg,cccl]==12.*",
  "cuda-toolkit[cufile]==12.*; sys_platform != 'win32'",
+ "cutensor-cu12",
  "nvidia-cublasmp-cu12; sys_platform != 'win32'",
  "nvidia-cudss-cu12",
  "nvidia-cufftmp-cu12; sys_platform != 'win32'",
@@ -28,6 +29,7 @@ cu12 = [
 cu13 = [
  "cuda-toolkit[nvcc,cublas,nvrtc,cudart,cufft,curand,cusolver,cusparse,npp,nvfatbin,nvjitlink,nvjpeg,cccl,nvvm]==13.*",
  "cuda-toolkit[cufile]==13.*; sys_platform != 'win32'",
+ "cutensor-cu13",
  "nvidia-cublasmp-cu13; sys_platform != 'win32'",
  "nvidia-cudss-cu13",
  "nvidia-nccl-cu13; sys_platform != 'win32'",

cuda_pathfinder/tests/local_helpers.py

@@ -0,0 +1,16 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+import functools
+import importlib.metadata
+import re
+
+
+@functools.cache
+def have_distribution(name_pattern: str) -> bool:
+ re_name_pattern = re.compile(name_pattern)
+ return any(
+ re_name_pattern.match(dist.metadata["Name"])
+ for dist in importlib.metadata.distributions()
+ if "Name" in dist.metadata
+ )