Latest results/All targets compares the last days' results for all targets in a specified branch. If you choose mainline from the branch menu, -Os from optimization flag, and Bar chart from data view you will get these.
On the first chart it can be seen that the mips-elf had the biggest code size, while on the second that the compilation time of mips-elf was longer than the others'. Finally, on the last chart it can be seen the execution time of arm-linux and i686-linux. To understand the difference between these, see the Technical details page.