NGEN_ASM support is incomplete

[nwnk]

It looks like it simply never gets built. ngen_asm.hpp is the only place that defines NGEN_ASM, and the only place that includes it looks like:

#ifdef NGEN_ASM
#include "ngen_asm.hpp"
NGEN_REGISTER_DECL(NGEN_NAMESPACE::AsmCodeGenerator, /* nothing */)
#endif

Simply defining the macro is not enough, because unlike the per-gen generators there is no ELFCodeGenerator that derives from AsmCodeGenerator.

[densamoilov]

+@petercad

[petercad]

@nwnk You're right that ngen_asm.hpp isn't used within oneDNN, and actually, it may be deleted. Like the rest of nGEN it's a header-only library and is only built as needed.

[nwnk]

@petercad

@nwnk You're right that ngen_asm.hpp isn't used within oneDNN, and actually, it may be deleted. Like the rest of nGEN it's a header-only library and is only built as needed.

Are we sure? The nGEN README seems to mention assembly generation as a feature. I would have guessed that it was there for a reason like faster kernel compile times. If that doesn't provide any benefit over CLC then I'm all too happy to remove it, I just want to verify that it's truly unwanted.

[petercad]

@nwnk Yes, nGEN is a library used internally in oneDNN, but not all parts of it are used in oneDNN. I verified that oneDNN builds fine without ngen_asm.hpp.