warp.get_cpu_kernel_cache_key#

warp.get_cpu_kernel_cache_key(*, cpu_compiler_flags=None)[source]#

Return a key identifying the CPU compilation target for naming external kernel caches.

The key combines the Warp version, operating system, and CPU architecture with the target hash from Warp’s CPU object filenames. That hash covers the LLVM version, plus the host CPU’s ISA features when the resolved flags contain -march=native. This function does not compile kernels or require CUDA.

For immutable CI caches, also include a hash of application dependencies and source. Individual modules still use their own hashes for source and compilation options. Do not parse the returned string; its format and value may change between Warp releases as cache compatibility rules evolve.

Parameters:

cpu_compiler_flags (str | None) – CPU compiler flags for the target to identify. None inherits warp.config.cpu_compiler_flags at call time, including its fallback to -march=native. An empty string selects a generic CPU target. This argument does not change the compiler configuration. For a cache that mixes native and generic modules, pass "-march=native".

Returns:

A nonempty string identifying the CPU compilation target, such as "1.19.0-Linux-x86_64-1a2b3c4d".

Raises:

  • RuntimeError – The LLVM backend required for CPU compilation is unavailable.

  • RuntimeError – The CPU compiler flags include -fsanitize=address, but the warp-clang library was not built with AddressSanitizer.

Return type:

str

Example

Save and restore CPU kernels in a target-specific archive:

import shutil
from pathlib import Path

import warp as wp

archive = Path("kernel-caches") / f"warp-cpu-{wp.get_cpu_kernel_cache_key()}.zip"

if archive.exists():
    shutil.unpack_archive(archive, wp.config.kernel_cache_dir)

# Run your CPU kernels here, then save the updated cache.
archive.parent.mkdir(parents=True, exist_ok=True)
shutil.make_archive(str(archive.with_suffix("")), "zip", wp.config.kernel_cache_dir)

Persist kernel-caches across runs. This example updates one archive per target; append a dependency and source hash for immutable caches.