As example I take one line from Makefile output. I see here you using two optimization flags -O3 & -O2, but:
If you use multiple -O options, with or without level numbers, the last such option is the one that is effective.

gcc -g -O3 -ffast-math --param max-inline-insns-single=2400 -fkeep-inline-functions -Winline -DPACKAGE_DATA_DIR=\"/usr/local/share/flam3\" -g -O2 -o flam3-convert flam3-convert.o docstring.o ./.libs/libflam3.a -lm /usr/lib/libjpeg.so -lpthread /usr/lib/libxml2.so -lpng -lz