http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51374
--- Comment #4 from andyw at pobox dot com 2011-12-01 13:22:44 UTC --- Compiler command line & -v output showing configure options (thought I had pasted this in the initial report - apparently not.) Do not know what happened to the attachment, the box said text/plain... $ avr-gcc -mmcu=atmega128 -Wall -O2 -g -c -save-temps -v test.c Using built-in specs. COLLECT_GCC=avr-gcc COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/avr/4.6.2/lto-wrapper Target: avr Configured with: ../configure --target=avr --enable-languages=c,c++ --disable-nls --disable-libssp --with-dwarf2 : (reconfigured) ../configure --target=avr --enable-languages=c,c++ --disable-nls --disable-libssp --with-dwarf2 --with-gmp=/usr/local --with-mpc=/usr/local --with-mpfr=/usr/local Thread model: single gcc version 4.6.2 (GCC) COLLECT_GCC_OPTIONS='-mmcu=atmega128' '-Wall' '-O2' '-g' '-c' '-save-temps' '-v' /usr/local/libexec/gcc/avr/4.6.2/cc1 -E -quiet -v -imultilib avr51 test.c -mmcu=atmega128 -Wall -g -fworking-directory -O2 -fpch-preprocess -o test.i ignoring nonexistent directory "/usr/local/lib/gcc/avr/4.6.2/../../../../avr/sys-include" #include "..." search starts here: #include <...> search starts here: /usr/local/lib/gcc/avr/4.6.2/include /usr/local/lib/gcc/avr/4.6.2/include-fixed /usr/local/lib/gcc/avr/4.6.2/../../../../avr/include End of search list. COLLECT_GCC_OPTIONS='-mmcu=atmega128' '-Wall' '-O2' '-g' '-c' '-save-temps' '-v' /usr/local/libexec/gcc/avr/4.6.2/cc1 -fpreprocessed test.i -quiet -dumpbase test.c -mmcu=atmega128 -auxbase test -g -O2 -Wall -version -o test.s GNU C (GCC) version 4.6.2 (avr) compiled by GNU C version 4.1.2 20070925 (Red Hat 4.1.2-33), GMP version 4.3.2, MPFR version 2.4.2, MPC version 0.8.1 GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 GNU C (GCC) version 4.6.2 (avr) compiled by GNU C version 4.1.2 20070925 (Red Hat 4.1.2-33), GMP version 4.3.2, MPFR version 2.4.2, MPC version 0.8.1 GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: 8445704570d64b6b795b8847e7060bc6 test.c: In function '__vector_18': test.c:10:16: warning: unused variable 'data' [-Wunused-variable] COLLECT_GCC_OPTIONS='-mmcu=atmega128' '-Wall' '-O2' '-g' '-c' '-save-temps' '-v' /usr/local/lib/gcc/avr/4.6.2/../../../../avr/bin/as -mmcu=atmega128 -o test.o test.s COMPILER_PATH=/usr/local/libexec/gcc/avr/4.6.2/:/usr/local/libexec/gcc/avr/4.6.2/:/usr/local/libexec/gcc/avr/:/usr/local/lib/gcc/avr/4.6.2/:/usr/local/lib/gcc/avr/:/usr/local/lib/gcc/avr/4.6.2/../../../../avr/bin/ LIBRARY_PATH=/usr/local/lib/gcc/avr/4.6.2/avr51/:/usr/local/lib/gcc/avr/4.6.2/../../../../avr/lib/avr51/:/usr/local/lib/gcc/avr/4.6.2/:/usr/local/lib/gcc/avr/4.6.2/../../../../avr/lib/ COLLECT_GCC_OPTIONS='-mmcu=atmega128' '-Wall' '-O2' '-g' '-c' '-save-temps' '-v' $