On Tue, 17 Jul 2001, Brian Pane wrote: > dean gaudet wrote: > > >you might want to disassemble the functions in gdb (or using objdump) to > >make sure that gcc emits a single division instruction for the "x / 10", > >"x % 10" expressions -- i forget the cases where it can and can't do this. > >the low level div instruction is a two result opcode, quotient and > >remainder. if it isn't doing it, then figure out how to make it do that > >and you'll see even more improvement :) > > > I see one just idivl call in the output of gcc on x86. I assume > that means it has done the optimization, right?
yup, rad -- you should also see it use %eax (quotient) and %edx (remainder) after the opcode. -dean
