When you want to set the "powerpc" string as a value of a define (-D or #define), you get the integer value 1 instead of the string.
Here's an example : test.c : ----- Arch = ARCH ----- With the "powerpc" string (bug) : gcc -E -DARCH=powerpc test.c Result is : # 1 "test.c" # 1 "<built-in>" # 1 "<command line>" # 1 "test.c" Arch = 1 With another string (no bug) : gcc -E -DARCH=ia32 test.c Result is : # 1 "test.c" # 1 "<built-in>" # 1 "<command line>" # 1 "test.c" Arch = ia32 == GCC Config == Using built-in specs. Target: powerpc-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --program-suffix=-4.1 --enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug --enable-mpfr --disable-softfloat --enable-targets=powerpc-linux,powerpc64-linux --with-cpu=default32 --enable-checking=release powerpc-linux-gnu Thread model: posix gcc version 4.1.2 20061007 (prerelease) (Debian 4.1.1-16) -- Summary: Wrong preprocessing when value of a define is "powerpc" Product: gcc Version: 4.1.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: preprocessor AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: glibersat at linux62 dot org GCC build triplet: powerpc-linux-gnu GCC host triplet: powerpc-linux-gnu GCC target triplet: powerpc-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29546