xor %rdx,%rdx # clear any descriptor registers
xor %rdi,%rdi # that we can't be sure we'll
xor %rsi,%rsi # initialise properly. XX do r8-r15 too?
- shl $3,%rcx # (fixnumize num-args)
+ shl $N_FIXNUM_TAG_BITS,%rcx # (fixnumize num-args)
cmp $0,%rcx
je Ldone
mov 0(%rbx),%rdx # arg0