Configuration

Warp has settings at the global, module, and kernel level that can be used to fine-tune the compilation and verbosity of Warp programs. In cases in which a setting can be changed at multiple levels (e.g.: enable_backward), the setting at the more-specific scope takes precedence.

Global Settings

Settings can be modified by direct assignment before or after calling wp.init(), though some settings only take effect if set prior to initialization.

For example, the location of the user kernel cache can be changed with:

import os

import warp as wp

example_dir = os.path.dirname(os.path.realpath(__file__))

# set default cache directory before wp.init()
wp.config.kernel_cache_dir = os.path.join(example_dir, "tmp", "warpcache1")

wp.init()

Module Settings

Module-level settings to control runtime compilation and code generation may be changed by passing a dictionary of option pairs to wp.set_module_options().

For example, compilation of backward passes for the kernel in an entire module can be disabled with:

wp.set_module_options({"enable_backward": False})

The options for a module can also be queried using wp.get_module_options().

Field	Type	Default Value	Description
mode	String	Global setting	A module-level override of the warp.config.mode setting.
max_unroll	Integer	Global setting	A module-level override of the warp.config.max_unroll setting.
enable_backward	Boolean	Global setting	A module-level override of the warp.config.enable_backward setting.
fast_math	Boolean	False	If True, CUDA kernels will be compiled with the --use_fast_math compiler option, which enables some fast math operations that are faster but less accurate.
fuse_fp	Boolean	True	If True, allow compilers to emit fused floating point operations such as fused-multiply-add. This may improve numerical accuracy and is generally recommended. Setting to False can help ensuring that functionally equivalent kernels will produce identical results unaffected by the presence or absence of fused operations.
lineinfo	Boolean	Global setting	A module-level override of the warp.config.lineinfo setting.
compile_time_trace	Boolean	Global setting	A module-level override of the warp.config.compile_time_trace setting.
cuda_output	String	None	A module-level override of the warp.config.cuda_output setting.
block_dim	Integer	256	The number of CUDA threads per block that kernels in the module will be compiled for.
strip_hash	Boolean	False	If True, avoids using a content-based hash to identify the module and its functions.

Kernel Settings

Backward-pass compilation can be disabled on a per-kernel basis by passing the enable_backward argument into the @wp.kernel decorator as in the following example:

@wp.kernel(enable_backward=False)
def scale_2(
    x: wp.array(dtype=float),
    y: wp.array(dtype=float),
):
    y[0] = x[0] ** 2.0