On Wed, Aug 2, 2017 at 3:54 PM, Segher Boessenkool <seg...@kernel.crashing.org> wrote: > On Tue, Aug 01, 2017 at 01:50:14PM +0200, David Brown wrote: >> I would not expect that to be good at all. With no optimisation (-O0), >> gcc produces quite poor code - local variables are not put in registers >> or "optimised away", there is no strength reduction, etc. For an >> architecture like the AVR with a fair number of registers (32, albeit >> 8-bit registers) and relatively inefficient stack access, -O0 produces >> /terrible/ code. > > -Og is better though (better than any other -O for this test at least). > > The regression happened before 4.7, it seems the big jump was with 4.6? > So what happened there? This seems to happen on x86 as well, maybe > on everything.
And one function (of the two) shrinks compared to 3.4 and the other increases so the jumps are probably mis-bisected anyway. Richard. > > Segher
