- changed PARAM_STRING to use the passed string by reference instead of by value. The 3 instances where passing by value was needed now use PARAM_STRING_VAL.
On Windows none of this is needed, because we can generate a proper unwind frame for the JITed functions, but even on Linux, it would require manual additions to each single piece of native code that ever gets called from inside a JIT compiled function.
This is an utterly prohibitive proposition because it makes direct native calls a virtual impossibility
So, in order to get the thrown error properly presented both I_Error and ThrowAbortException will now forward to I_FatalError if it is called from inside a JIT context.
For the varargs functions that used the Type field to validate their parameters, now a hidden additional argument is passed which contains a byte array with the type info for the current call's arguments. Since this is static per call location it can be better prepared once when the code is being compiled instead of being put in a runtime created array for each invocation. Everything else uses the per-function instance of the same data.
The only thing that still needed the type field with a VMValue is the defaults array, so this uses a different struct type now to store its data.
Currently used for loading parameters into registers.
For checking parameters of native functions some more work is needed to get the info to the function. Currently it doesn't receive the function descriptor.
src/scripting/vm/jit_call.cpp:164:38: warning: offset of on non-standard-layout type 'VMScriptFunction' [-Winvalid-offsetof]
src/scripting/vm/jit_load.cpp:87:50: warning: offset of on non-standard-layout type 'DObject' [-Winvalid-offsetof]
src/scripting/vm/jit_load.cpp:96:50: warning: offset of on non-standard-layout type 'DObject' [-Winvalid-offsetof]
src/scripting/vm/jit_load.cpp:257:53: warning: offset of on non-standard-layout type 'DObject' [-Winvalid-offsetof]
The amount of support code for this minor optimization was quite large and this stood in the way of streamlining the VM's calling convention, so it was preferable to remove it before moving on.
With a proper count value available this can be done properly. The only relevant targets are the jumps immediately succeeding the IJMP instructions, nothing else.
