Hello,
I have a question regarding compiler optimization of a cross compiler GCC (m68k). We are using version 3.4.0. When activating compiler optimization with the options =84- O1, -O2, - O3 =93 there is a number of individual optimization flags set in the background. With =84- O1 =93 there are, as in the GNU documentation described, at least 10 optimization flags (-funit-at-a-time, -fomit- frame-pointer, -fdefer-pop, -fmerge-constants, -fthread-jumps, -floop- optimize, -fif-conversion, -fif-conversion2, -fdelayed-branch, -fguess- branch-probability, -fcprop-registers).
The following sentence in the GNU documentation makes us very curious : Chapter =933.10 Options That Control Optimization=94 -> =84Not al= l optimizations are controlled directly by a flag. Only optimizations that have a flag are listed. =93
Does anyone have experience what are the additional optimizations? Is there a description existing? Why is it not possible to control them via flags?
Thanks for your help.