[QST] if(runtime_value) (cute::copy or cute::gemm) Generates NaNs

What is your question?

Hello! I encountered this weird case when debugging my kernel.
I have some cute::copy and cute::gemm which work perfectly like a charm.

Now that I've determined to introduce some conditional statements for these operations. I could have defined a template<bool Enable> my_kernel to make this Enable static.

However, I tried simply doing:

if(enable) { cute::copy(xx);  cute::gemm(xx);}

For which enable is a runtime variable that's passed into the kernel as a parameter.

All of a sudden my kernel started to generate nan values (even if I did pass enable as a true value).
When changing this to:

if(true) { cute::copy(xx); cute::gemm(xx);}

my kernel works again.

I'm generally wondering if you could help me understand what happens if I wrote something like this, and in general if this is not recommended.

Thank you so much!

The report names cute::copy, cute::gemm, and a kernel parameter named enable, but no source file or test. Start with a minimal kernel comparing if(enable) with if(true), run both with enable=true, and document the conditions that produce NaNs. Done means the runtime-conditional behavior has a reproducible explanation and expected outcome.