On Tue, Jan 25, 2011 at 05:04:01PM +0800, Ray Will wrote: > The following two lines should be merged into one inst. It is the tlb > refill handler, quite time sensitive. > 569 uasm_i_lui(p, tmp, PM_HUGE_MASK >> 16); > 570 uasm_i_ori(p, tmp, tmp, PM_HUGE_MASK & 0xffff); > > Merged to > uasm_i_lui(p, tmp, ((PM_HUGE_MASK & 0xffff) | (PM_HUGE_MASK >> 16)); With 4K pages (=> 1M huge pages) we'd want the value 0x001fe000 to be loaded. Your change results in in a LUI $tmp, 0xe01f instruction being generated and that's an illegal value for the c0_pagemask register so the operation is now architecturally undefined. Similar for other page sizes. All possible values for PM_HUGE_MASK will have bits set in the upper and lower 16 halves of the register so there will always two instructions be required to load the pagemask value. Ralf
