Setting float prescise/fast at com… | Apple Developer Forums

I'm trying to compile some compute kernel source, and force it to all run precise or fast.

The docs (https://developer.apple.com/documentation/metal/mtlcompileoptions/1515914-fastmathenabled?language=objc)say of MTLCompileOptions.fastMathEnabled -- The default value is

YES

. A

YES

value also enables the high-precision variant of math functions for single-precision floating-point scalar and vector types.

Is this a typo? NO would enable high precision, correct?

Second, it appears I can do this with a c++ namespace in the kernel source itself. Am I correct that doing so will override the setting in MTLCompileOptions.fastMathEnabled?

Can I wrap my kernel in

using namespace metal::fast // metal::precise

to get all float math to compile is one variant or the other? Will this change simple float operations as well? or just functions like clamp/saturate?

Thanks,

mike

Setting float prescise/fast at compile time?