Hi Rich,
ldd was the first to check and dependencies are the same. It was not surprise because lua binary is linked with liblua.a:
gcc -flto -march=i486 -mtune=i686 -Os -pipe -std=gnu99 -o lua lua.o liblua.a -lm -Wl,-E -ldl -lreadline -lncursesw
Fast incarnation of lua-5.3.6 in TC13 x86 was compiled literally following recipe, using the same -march=i486 and -mtune=i686.
But!!!
I've made the thing I was to do before - compiled the same lua source using the same recipe, but under TC12 x86. And this lua binary is slowpoke! The only difference is gcc version.
I've compiled lua extensions for my needs in TC13 x86 using -no-unwind-tables and -fno-asynchronous-unwind-tables as You proposed earlier for pure C code, binary sizes decreased significantly.
Should we dig further? It may be useful, but I have no ideas in what direction. It may be useful for another extensions packing too.
Thanks!