The default math functions in .Net are realized with static methods from the
However, many operations work on doubles by default (like
Math.Sin) and there is often no float overload.
This causes many floating-point operations to be performed on 64-bit floats, even when this precision is not required.
.Net Core and .Net Standard compatible frameworks ship the
MathF class to overcome this limitation.
ILGPU offers the
IntrinsicMath class that supports basic math operations which are supported on all target platforms.
The algorithms library offers the
XMath class that has support for all common 32-bit float and 64-bit float math
Using the 32-bit overloads ensure that the operations are performed on 32-bit floats on the GPU hardware.
Fast-math can be enabled using the
Math(MathMode.Fast) method of
Context.Builder and enables the use of fast (and
unprecise) math functions.
Unlike previous versions, the fast-math mode applies to all math instructions. Even to default math operations
x / y.
Forced 32-bit Math
Your kernels might rely on third-party functions that are not under your control.
These functions typically depend on the default .Net
Math class, and thus, work on 64-bit floating-point operations.
You can force the use of 32-bit floating-point operations in all cases using the
Caution: all doubles will be considered as floats to circumvent issues with third-party code.
However, this also affects the address computations of array-view elements.
Avoid the use of this flag unless you know exactly what you are doing.