[Bug gcov-profile/83478] New: [GCOV] if condition with ~ unsigned short lead to incorrect coverage in gcov

[yangyibiao at nju dot edu.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83478

            Bug ID: 83478
           Summary: [GCOV] if condition with ~ unsigned short lead to
                    incorrect coverage in gcov
           Product: gcc
           Version: 7.2.0
            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/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 7.2.0-8ubuntu3'
--with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr
--with-gcc-major-version-only --program-suffix=-7
--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 7.2.0 (Ubuntu 7.2.0-8ubuntu3)

$ cat small.c
int func(unsigned short p1, unsigned int p2)
{
    int i = 0;
    if (~p1) 
        i = i + 1;

    if ((unsigned int)(~p1)) 
        i = i + 2;

    if (~p2) 
        i = i + 4;

    return i;
}

int main ()
{
    func(0, 0);
}

$ gcc -fprofile-arcs -ftest-coverage small.c; ./a.out; gcov small.c; 
cat File 'seed.c'
Lines executed:100.00% of 10
Creating 'seed.c.gcov'

        -:    0:Source:small.c
        -:    0:Graph:small.gcno
        -:    0:Data:small.gcda
        -:    0:Runs:1
        -:    0:Programs:1
        1:    1:int func(unsigned short p1, unsigned int p2)
        -:    2:{
        1:    3:    int i = 0;
        -:    4:    if (~p1) 
        1:    5:        i = i + 1;
        -:    6:
        1:    7:    if ((unsigned short)(~p1))
        1:    8:        i = i + 2;
        -:    9:
        1:   10:    if (~p2) 
        1:   11:        i = i + 4;
        -:   12:
        1:   13:    return i;
        -:   14:}
        -:   15:
        1:   16:int main ()
        -:   17:{
        1:   18:    func(0, 0);
        -:   19:}


================================================
As we can find that Line #4, Line #7, and Line #10 are respectively marked as
not executed, executed, and executed. 

I was wondering whether there is a bug here. 

Since the arguments of "func" p1 and p2 are both unsinged variables. Line #4
and Line #10 should has the same mark.