------- Comment #19 from bonzini at gnu dot org 2007-12-19 12:13 -------
Created an attachment (id=14792)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=14792&action=view)
patch to almost fix the bug
With this patch:
1) local-alloc first tries to allocate registers that go into small classes
2) regclass tries to use the same class for an output and an input that dies
3) i386 modes_tiable_p allows tying SImode with DImode (but not vice versa)
I get now this:
pushl %esi
pushl %ebx
movl 12(%esp), %ecx
movl 20(%esp), %eax
movl 24(%esp), %ebx
imull %ecx, %ebx
movl 16(%esp), %esi
imull %eax, %esi
addl %esi, %ebx
mull %ecx
leal (%ebx,%edx), %edx
popl %ebx
popl %esi
which has no moves. It still spills two registers because it is not able to
use %edx (I'll look into it later).
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17236
