build_fake_control_stack_frames(context);
/* signal handler will "return" to this error-causing function */
*os_context_pc_addr(context) = function;
-#ifndef LISP_FEATURE_X86
+#ifdef LISP_FEATURE_X86
/* this much of the calling convention is common to all
non-x86 ports */
+ *os_context_register_addr(context,reg_ECX) = 0;
+#else
*os_context_register_addr(context,reg_NARGS) = 0;
*os_context_register_addr(context,reg_LIP) = function;
*os_context_register_addr(context,reg_CFP) =