So, here is a comparison of the time required to do a make -j15 of a --disable-bootstrap --enable-checking=none --enable-languages=c,c++ style compiler. The base compiler is a --enable-checking=none --enable-languages=c,c++,lto style compiler, which is 1b2bf75690af8115739ebba710a44d05388c7a1a (aka trunk@202797) from git. The wide branch compiler is 4529820913813b810860784382f975ea8e6be61d (aka wide-int@203462) from git. The software compiled in both cases is the base compiler described above.
Net result, around 2.6% regression in user time, and 0.4% in elapsed time. The raw data is below, just in case one is interested. This is on Ubuntu 12.04.3 system with 12GB ram with 8 cores. wide branch: 1760.94user 145.78system 5:06.23elapsed 622%CPU (0avgtext+0avgdata 2317824maxresident)k 32976inputs+5713232outputs (1487major+72639003minor)pagefaults 0swaps 1758.53user 145.40system 5:06.66elapsed 620%CPU (0avgtext+0avgdata 2317808maxresident)k 1104inputs+5713240outputs (9major+72644909minor)pagefaults 0swaps 1751.91user 145.77system 5:05.27elapsed 621%CPU (0avgtext+0avgdata 2317808maxresident)k 0inputs+5713232outputs (0major+72652872minor)pagefaults 0swaps 1751.29user 145.78system 5:06.15elapsed 619%CPU (0avgtext+0avgdata 2317808maxresident)k 8inputs+5713256outputs (0major+72647952minor)pagefaults 0swaps 1755.10user 145.26system 5:02.74elapsed 627%CPU (0avgtext+0avgdata 2317808maxresident)k 96inputs+5713264outputs (1major+72642787minor)pagefaults 0swaps base: 1708.71user 145.02system 5:04.98elapsed 607%CPU (0avgtext+0avgdata 2317824maxresident)k 0inputs+5713448outputs (0major+72602789minor)pagefaults 0swaps 1707.43user 145.56system 5:05.24elapsed 607%CPU (0avgtext+0avgdata 2317808maxresident)k 0inputs+5713424outputs (0major+72606028minor)pagefaults 0swaps 1711.61user 145.53system 5:03.49elapsed 611%CPU (0avgtext+0avgdata 2317808maxresident)k 160inputs+5713424outputs (6major+72614090minor)pagefaults 0swaps 1712.64user 145.25system 5:02.98elapsed 613%CPU (0avgtext+0avgdata 2317808maxresident)k 0inputs+5713432outputs (0major+72599974minor)pagefaults 0swaps 1708.81user 144.66system 5:01.61elapsed 614%CPU (0avgtext+0avgdata 2317808maxresident)k 24inputs+5713448outputs (0major+72599501minor)pagefaults 0swaps
