On Fri, 17 Feb 2017, Thomas Schwinge wrote: > On Fri, 17 Feb 2017 14:00:09 +0100, I wrote: > > [...] for "normal" functions there is no reason to use the > > ".param" space for passing arguments in and out of functions. We can > > then get rid of the boilerplate code to move ".param %in_ar*" into ".reg > > %ar*", and the other way round for "%value_out"/"%value". This will then > > also simplify the call sites, where all that code "evaporates". That's > > actually something I started to look into, many months ago, and I now > > just dug out those changes, and will post them later. > > > > (Very likely, the PTX "JIT" compiler will do the very same thing without > > difficulty, but why not directly generate code that is less verbose to > > read?)
In general you cannot use this shorthand notation because PTX interop guidelines explicitly prescribe using the .param space for argument passing. See https://docs.nvidia.com/cuda/ptx-writers-guide-to-interoperability/ , section 3. So at best GCC can use it for calls where interop concerns are guaranteed to not arise: when the callee is not externally visible, and does not have its address taken. And there's a question of how well it's going to work after time passes, since other compilers always use the verbose form (and thus the .reg calling style is not frequently exercised). Alexander
