+ .text
+ .align align_16byte,0x90
+ .globl GNAME(undefined_alien_function)
+ TYPE(GNAME(undefined_alien_function))
+GNAME(undefined_alien_function):
+ pop 8(%rbp) # Save return PC for backtrace.
+ TRAP
+ .byte trap_Error
+ .byte 4
+ .byte UNDEFINED_ALIEN_FUN_ERROR
+ /* Encode RBX
+ FIXME: make independt of the encoding changes. */
+ .byte 0xFE
+ .byte 0x9F
+ .byte 0x01
+ ret
+ SIZE(GNAME(undefined_alien_function))
+
+/* KLUDGE: FIND-ESCAPED-FRAME (SYS:SRC;CODE;DEBUG-INT.LISP) needs
+ * to know the name of the function immediately following the
+ * undefined-function trampoline. */
+
+/* Our call-site does not take care of caller-saved xmm registers, so it
+ * falls to us spill them beforing hopping into C.
+ *
+ * We simply save all of them.
+ *
+ * (But for the sake of completeness, here is my understanding of the specs:)
+ * System V Microsoft
+ * argument passing xmm0-7 xmm0-3
+ * caller-saved xmm8-15 xmm4-5
+ * callee-saved - xmm6-15
+ *
+ * --DFL */
+
+#define stkxmmsave(n) movaps %xmm##n, n*16(%rsp)
+#define stkxmmload(n) movaps n*16(%rsp), %xmm##n
+#define map_all_xmm(op) \
+ op(0);op(1);op(2);op(3);op(4);op(5);op(6);op(7); \
+ op(8);op(9);op(10);op(11);op(12);op(13);op(14);op(15);