Caller-saves regs have to be saved around C-calls made from STG
land, so this file defines CALLER_SAVES_<reg> for each <reg> that
is designated caller-saves in that machine's C calling convention.
+
+ As it stands, the only registers that are ever marked caller saves
+ are the RX, FX, DX and USER registers; as a result, if you
+ decide to caller save a system register (e.g. SP, HP, etc), note that
+ this code path is completely untested! -- EZY
-------------------------------------------------------------------------- */
/* -----------------------------------------------------------------------------