Calling all flags -Os use manually does not produce same results (GCC)

Question

I compile with -O1 and manually use the following flags:

          -fthread-jumps 
          -falign-functions  -falign-jumps 
          -falign-loops  -falign-labels 
          -fcaller-saves 
          -fcrossjumping 
          -fcse-follow-jumps  -fcse-skip-blocks 
          -fdelete-null-pointer-checks 
          -fdevirtualize 
          -fexpensive-optimizations 
          -fgcse  -fgcse-lm  
          -fhoist-adjacent-loads 
          -finline-small-functions 
          -findirect-inlining 
          -fipa-sra 
          -foptimize-sibling-calls 
          -fpartial-inlining 
          -fpeephole2 
          -fregmove 
          -freorder-blocks  -freorder-functions 
          -frerun-cse-after-loop  
          -fsched-interblock  -fsched-spec 
          -fschedule-insns  -fschedule-insns2 
          -fstrict-aliasing -fstrict-overflow 
          -ftree-switch-conversion -ftree-tail-merge 
          -ftree-pre 
          -ftree-vrp

except

          -falign-functions  -falign-jumps  -falign-loops 
          -falign-labels  -freorder-blocks  -freorder-blocks-and-partition 
          -fprefetch-loop-arrays  -ftree-vect-loop-version

which should correspond to what -Os does according to https://gcc.gnu.org/onlinedocs/gcc-4.8.0/gcc/Optimize-Options.html (I use GCC 4.8.2). However, the resulting binaries are not the same as when I use -Os.

(Note, I am cross-compiling for mcu68332).

Why is this the case?