------- Comment #4 from fredrik dot hederstierna at securitas-direct dot com 2010-08-06 09:09 ------- Hm, I now tried to disable all possible optimization flags, but still "-Os" does not work, but "-O2" still works!
Does the "-Os" option do anything more that is not controllable from command line options/flags? # Disable O1 flags CFLAGS += -fno-auto-inc-dec CFLAGS += -fno-cprop-registers CFLAGS += -fno-dce CFLAGS += -fno-defer-pop CFLAGS += -fno-delayed-branch CFLAGS += -fno-dse CFLAGS += -fno-guess-branch-probability CFLAGS += -fno-if-conversion2 CFLAGS += -fno-if-conversion CFLAGS += -fno-ipa-pure-const CFLAGS += -fno-ipa-reference CFLAGS += -fno-merge-constants CFLAGS += -fno-split-wide-types CFLAGS += -fno-tree-builtin-call-dce CFLAGS += -fno-tree-ccp CFLAGS += -fno-tree-ch CFLAGS += -fno-tree-copyrename CFLAGS += -fno-tree-dce CFLAGS += -fno-tree-dominator-opts CFLAGS += -fno-tree-dse CFLAGS += -fno-tree-forwprop CFLAGS += -fno-tree-fre CFLAGS += -fno-tree-phiprop CFLAGS += -fno-tree-sra CFLAGS += -fno-tree-pta CFLAGS += -fno-tree-ter CFLAGS += -fno-unit-at-a-time # Disable O2 flags CFLAGS += -fno-thread-jumps CFLAGS += -fno-align-functions -fno-align-jumps CFLAGS += -fno-align-loops -fno-align-labels CFLAGS += -fno-caller-saves CFLAGS += -fno-crossjumping CFLAGS += -fno-cse-follow-jumps -fno-cse-skip-blocks CFLAGS += -fno-delete-null-pointer-checks CFLAGS += -fno-expensive-optimizations CFLAGS += -fno-gcse -fno-gcse-lm CFLAGS += -fno-inline-small-functions CFLAGS += -fno-indirect-inlining CFLAGS += -fno-ipa-sra CFLAGS += -fno-optimize-sibling-calls CFLAGS += -fno-peephole2 CFLAGS += -fno-regmove CFLAGS += -fno-reorder-blocks -fno-reorder-functions CFLAGS += -fno-rerun-cse-after-loop CFLAGS += -fno-sched-interblock -fno-sched-spec CFLAGS += -fno-schedule-insns -fno-schedule-insns2 CFLAGS += -fno-strict-aliasing -fno-strict-overflow CFLAGS += -fno-tree-switch-conversion CFLAGS += -fno-tree-pre CFLAGS += -fno-tree-vrp # Disable flags for debugging purposes CFLAGS += -fno-omit-frame-pointer -fno-web The code size increased alot when disabling all this options. /Fredrik -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45207
