https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89467
Bug ID: 89467 Summary: [GCOV] wrong freqencies when there is comparison operator in the right side of the assignment statement Product: gcc Version: 8.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: gcov-profile Assignee: unassigned at gcc dot gnu.org Reporter: yangyibiao at nju dot edu.cn CC: marxin at gcc dot gnu.org Target Milestone: --- $ 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 8.2.0-1ubuntu2~18.04' --with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs --enable-languages=c,ada,c++,go,brig,d,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 --with-target-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 --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 8.2.0 (Ubuntu 8.2.0-1ubuntu2~18.04) $ cat small.c void foo(int p) { int e; int b = 0, f = 0, d = 0; if ((p < f) && p) { L: for (e = 0; 0;) ; } else if (d) { b = (0 >= b); } for (; e <= 3; e++) { if (b) { continue; } b = 3; goto L; } } void main() { int a = -1; foo(a); } $ gcc -O0 --coverage small.c -w; ./a.out; gcov small.c; cat small.c.gcov File 'small.c' Lines executed:87.50% of 16 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 foo(int p) -: 2:{ -: 3: int e; 1: 4: int b = 0, f = 0, d = 0; 3: 5: if ((p < f) && p) { 1: 6:L: 2: 7: for (e = 0; 0;) ; #####: 8: } else if (d) { #####: 9: b = (0 >= b); -: 10: } -: 11: 6: 12: for (; e <= 3; e++) { 5: 13: if (b) { continue; } 1: 14: b = 3; 1: 15: goto L; -: 16: } 1: 17:} -: 18: 1: 19:void main() -: 20:{ 1: 21: int a = -1; 1: 22: foo(a); 1: 23:} Line #5 is wrongly marked as executed 3 times which should be only executed once. When Line #9 is removed, the coverage report will be correct as: $ gcc -O0 --coverage small.c -w; ./a.out; gcov small.c; cat small.c.gcov File 'small.c' Lines executed:100.00% of 14 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 foo(int p) -: 2:{ -: 3: int e; 1: 4: int b = 0, f = 0, d = 0; 1: 5: if ((p < f) && p) { 1: 6:L: 2: 7: for (e = 0; 0;) ; -: 8: } else if (d) { -: 9: // b = (0 >= b); -: 10: } -: 11: 6: 12: for (; e <= 3; e++) { 5: 13: if (b) { continue; } 1: 14: b = 3; 1: 15: goto L; -: 16: } 1: 17:} -: 18: 1: 19:void main() -: 20:{ 1: 21: int a = -1; 1: 22: foo(a); 1: 23:}