On 23 August 2013 22:18, Richard Henderson <r...@twiddle.net> wrote: > E.g. tci never defines TCG_TARGET_CALL_ALIGN_ARGS. Thus if one uses tci on an > ARM host, a helper like > > DEF_HELPER_FLAGS_2(store_fpcr, TCG_CALL_NO_RWG, void, env, i64) > > will have its arguments loaded into TCI's R0, R1, R2, and thence into the ARM > r0, r1, r2. But the ARM abi requires the i64 input to be aligned, and thus it > should be r0, r2, r3.
Oh, TCI does that? That's just broken -- you can't treat all helpers the same that way. You either need to have a bit of per-CPU glue code which knows how to adjust things to the calling convention (which would defeat the point of TCI being CPU-independent) or you need to defer to a library that can do it (libffi would be the obvious choice) or you need to actually have the C code in the interpreter make the call with all the correct argument types (should be technically possible for qemu I guess since we have a fixed set of helper functions and we know the types at compile time, though it might be kind of painful). -- PMM
