On Thu, Jun 18, 2020 at 5:26 PM John Fastabend <john.fastabend@xxxxxxxxx> wrote: > > foo(int a, __int128 b) > > would put a in r0 and b in r2 and r3 leaving a hole in r1. But that > was some old reference manual and might no longer be the case > in reality. Perhaps just spreading hearsay, but the point is we > should say something about what the BPF backend convention > is and write it down. We've started to bump into these things > lately. calling convention for int128 in bpf is _undefined_. calling convention for struct by value in bpf is also _undefined_. In many cases the compiler has to have the backend code so other parts of the compiler can function. I didn't bother explicitly disabling every undefined case. Please don't read too much into llvm generated code.
