Hi all, I have a gcc question and hopefully someone can help me out. Let's say I have two compilers. Compiler GCC_A & GCC_B: *GCC_A:* Host compiler - i686. This compiler was used to build compiler B with optimization for pentium4 (--with-arch=pentium4). The configure parameters to build compiler B is as follow: Target: i686-t2-linux-gnu Configured with: ../configure --prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --libdir=/usr/lib --datadir=/usr/share --includedir=/usr/include --infodir=/usr/info --mandir=/usr/man --sysconfdir=/etc --localstatedir=/var --disable-debug --with-libpam --with-pam --enable-libpam --enable-pam --with-mysql-lib=/usr/lib/mysql --with-mysql-include=/usr/include/mysql --with-mysql-lib=/usr/lib/mysql --with-mysql-include=/usr/include/mysql --build=i686-t2-linux-gnu --host=i686-t2-linux-gnu --target=i686-t2-linux-gnu --enable-install-libiberty=no --disable-install-libiberty --with-arch=pentium4 --with-arch=pentium4 --enable-__cxa_atexit --disable-checking --disable-bootstrap --disable-libstdcxx-pch --disable-multilib --disable-target-libiberty --with-gnu-as --with-gnu-ld --enable-threads=posix --enable-languages=c,c++,objc,go --enable-shared Thread model: posix gcc version 4.8.5 (GCC) *GCC_B:* Target/Build compiler for x86 pentium4. This compiler is used to build root-filesystem for target board: x86 pentium4. In theory, this compiler does not generate any code (ie avx1 avx2 sse3 sse3 sse4.1) not supported by the intel pentium4 processor. *My question is: * can I use compiler B with added compiler flags (-mavx -mavx2 -march=corei7) to force compiler B to generate code for higher CPU support? So far, I haven't been able to do so because compiler B wouldn't be able to compile vectorized instruction sets (ie. avx+avx2+SSE)? I am not sure if it is something I did wrong or that it is completely impossible. Thank you. TP
