https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85201
--- Comment #1 from Yibiao Yang <yangyibiao at nju dot edu.cn> --- (In reply to Yibiao Yang from comment #0) > $ gcc -v > gcc -v > Using built-in specs. > COLLECT_GCC=gcc > COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper > OFFLOAD_TARGET_NAMES=nvptx-none > OFFLOAD_TARGET_DEFAULT=1 > Target: x86_64-linux-gnu > Configured with: ../src/configure -v --with-pkgversion='Ubuntu > 8-20170923-1ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs > --enable-languages=c,c++,go,brig,fortran,objc,obj-c++ --prefix=/usr > --with-gcc-major-version-only --program-suffix=-8 > --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id > --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix > --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu > --enable-libstdcxx-debug --enable-libstdcxx-time=yes > --with-default-libstdcxx-abi=new --enable-gnu-unique-object > --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie > --with-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror > --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 > --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none > --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu > --target=x86_64-linux-gnu > Thread model: posix > gcc version 8.0.0 20170923 (experimental) [trunk revision 253118] (Ubuntu > 8-20170923-1ubuntu2) > > $ cat small.c > void main() { > int a = 0; > int b = 0; > int c = 0; > for (; a >= 0; a--) { > (c && b, 1) && b; > } > } > > $ gcc -w --coverage small.c; ./a.out; gcov-8 small.c; cat small.c.gcov > File 'small.c' > Lines executed:100.00% of 7 > Creating 'small.c.gcov' > > -: 0:Source:small.c > -: 0:Graph:small.gcno > -: 0:Data:small.gcda > -: 0:Runs:1 > -: 0:Programs:1 > 1: 1:void main() { > 1: 2: int a = 0; > 1: 3: int b = 0; > 1: 4: int c = 0; > 2: 5: for (; a >= 0; a--) { > 2: 6: (c && b, 1) && b; I am not sure this is a duplication of bug 85163. When changing the operators in the code of bug 85163, the result is correct. While changing '&&' to '||' of the code here, the problem is still exist. > -: 7: } > 1: 8:} > > > Line #6 is wrongly marked as executed twice.