------- Comment #25 from bonzini at gnu dot org 2007-12-19 13:50 ------- Note that "fwprop" is not an exact term, because there *is* a memory load in each multiplication, and propagating a second memory operand will create an invalid insn. You may try to add a split from reg=op(mem1, mem2) to reg=mem1;reg=reg*mem2, but anyway, it won't help propagating into the mull, since it is not LOG_LINKS-related to the load.
The problem is that we end up with having to reload *anyway*. If we had a way to express the relationship between operands 0 and 1 of the multiplication *before reload*, probably the RTL optimizations could do much more. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17236
