On Tue, Jun 12, 2018 at 10:44 PM, Jeff Law wrote: > On 06/05/2018 01:15 AM, marxin wrote: >> >> + The definition of "much bigger" depends on whether we are >> + optimizing for size or for speed. If the former, the maximum >> + ratio range/count = 3, because this was found to be the optimal >> + ratio for size on i686-pc-linux-gnu, see PR11823. The ratio >> + 10 is much older, and was probably selected after an extensive >> + benchmarking investigation on numerous platforms. Or maybe it >> + just made sense to someone at some point in the history of GCC, >> + who knows... */ > "much older" is an understatement. I believe the magic "10" pre-dates > my involvement in GCC. You can find evidence of it as far back as > gcc-0.9. I doubt it was extensively benchmarked, and even if it was, > the targets on which it was benchmarked don't reflect modern target > reality in terms of importance.
When I added this comment (https://gcc.gnu.org/viewcvs/gcc/trunk/gcc/stmt.c?r1=189284&r2=189285&;) it as an attempt at humor. I should have turned the number into a PARAM at the time. Maybe that's something Martin could still do now? Ciao! Steven
