https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416
--- Comment #7 from Martin Reinecke <mar...@mpa-garching.mpg.de> --- Here is the output of --verbose: martin@martin-Latitude-E7450 ~/tmp $ gcc -O3 testcase2.c --verbose -lm -S Using built-in specs. COLLECT_GCC=gcc Target: x86_64-pc-linux-gnu Configured with: /home/martin/codes/gccgit/configure --disable-bootstrap --disable-multilib --prefix=/home/martin/codes/utrunk --enable-languages=c++,fortran --enable-target=all --enable-checking=release Thread model: posix gcc version 8.0.1 20180411 (experimental) [trunk revision b3ed066d3a5:895af22275d:7d24c3846c904b6e1ffea0bee0c58a9f7bcc23cb] (GCC) COLLECT_GCC_OPTIONS='-O3' '-v' '-S' '-mtune=generic' '-march=x86-64' /home/martin/codes/utrunk/libexec/gcc/x86_64-pc-linux-gnu/8.0.1/cc1 -quiet -v -imultiarch x86_64-linux-gnu testcase2.c -quiet -dumpbase testcase2.c -mtune=generic -march=x86-64 -auxbase testcase2 -O3 -version -o testcase2.s GNU C17 (GCC) version 8.0.1 20180411 (experimental) [trunk revision b3ed066d3a5:895af22275d:7d24c3846c904b6e1ffea0bee0c58a9f7bcc23cb] (x86_64-pc-linux-gnu) compiled by GNU C version 5.4.0 20160609, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.16.1-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu" ignoring nonexistent directory "/home/martin/codes/utrunk/lib/gcc/x86_64-pc-linux-gnu/8.0.1/../../../../x86_64-pc-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /home/martin/codes/utrunk/lib/gcc/x86_64-pc-linux-gnu/8.0.1/include /usr/local/include /home/martin/codes/utrunk/include /home/martin/codes/utrunk/lib/gcc/x86_64-pc-linux-gnu/8.0.1/include-fixed /usr/include/x86_64-linux-gnu /usr/include End of search list. GNU C17 (GCC) version 8.0.1 20180411 (experimental) [trunk revision b3ed066d3a5:895af22275d:7d24c3846c904b6e1ffea0bee0c58a9f7bcc23cb] (x86_64-pc-linux-gnu) compiled by GNU C version 5.4.0 20160609, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.16.1-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: 08c992208389b44fd477c64ce2b4d084 COMPILER_PATH=/home/martin/codes/utrunk/libexec/gcc/x86_64-pc-linux-gnu/8.0.1/:/home/martin/codes/utrunk/libexec/gcc/x86_64-pc-linux-gnu/8.0.1/:/home/martin/codes/utrunk/libexec/gcc/x86_64-pc-linux-gnu/:/home/martin/codes/utrunk/lib/gcc/x86_64-pc-linux-gnu/8.0.1/:/home/martin/codes/utrunk/lib/gcc/x86_64-pc-linux-gnu/ LIBRARY_PATH=/home/martin/codes/utrunk/lib/gcc/x86_64-pc-linux-gnu/8.0.1/:/home/martin/codes/utrunk/lib/gcc/x86_64-pc-linux-gnu/8.0.1/../../../../lib64/:/lib/x86_64-linux-gnu/:/lib/../lib64/:/usr/lib/x86_64-linux-gnu/:/home/martin/codes/utrunk/lib/gcc/x86_64-pc-linux-gnu/8.0.1/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-O3' '-v' '-S' '-mtune=generic' '-march=x86-64'