Re: Unresolved symbol __multi3

>depmod: *** Unresolved symbols in /lib/modules/2.4.9-34/misc/lns.o
>depmod:     __multi3

That is a libgcc routine to perform 128-bit integer multiply.

Since there is no 128-bit integer type, this is usually an artifact of gcc
internals.  Gcc represents object sizes internally in bits, so that we can
handle bit-fields, bit-vectors, and other bit oriented types.  Unfortunately,
this means we need 67-bit values to span the entire address space, so we hold
them as 128-bit values.  If we need to multiply an object size, that means
we need a 128-bit multiply.  One way this can happen in user code is when you
dynamically allocate a variable length array.  This testcase for instance:
struct foo { int i; };
void sub (int i) { struct foo bar[i]; sub2 (&bar); }
If I compile this without optimization, I get a call to __multi3.  This
is becuse we need to multiply 'i' by sizeof (struct foo) at runtime, and
sizeof struct foo is represented internally to gcc as a 128-bit value.  If
I compile with optimization, the __multi3 call is optimized away.  The multi3
call is of course unecessary, even when not optimizing, and this problem is
already fixed in gcc-3.1.  If I compile this example with gcc-3.1 without
optimization, I do not get a multi3 call.

Jim