------- Comment #22 from ubizjak at gmail dot com 2007-12-19 13:11 ------- (In reply to comment #21)
> Indeed, if I only use the regclass.c and local-alloc.c hunks, I get only one > spill! > > pushl %ebx > movl 8(%esp), %edx > movl 16(%esp), %eax > movl 20(%esp), %ecx > imull %edx, %ecx > movl 12(%esp), %ebx > imull %eax, %ebx > addl %ebx, %ecx > mull %edx > leal (%ecx,%edx), %edx > popl %ebx > > and no reg-reg move. Excellent! I think that we should fwprop stack arguments into the insns to further optimize the code. According to pentopt.pdf, there is no penalty at all (at least for P4+) when one of the insn operands is a memory reference. This would relieve register pressure considerably. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17236