[Bug gcov-profile/85367] New: [GCOV] A call to the _subborrow_u64 builtin-function is wrongly marked as executed twice
yangyibiao at nju dot edu.cn
gcc-bugzilla@gcc.gnu.org
Thu Apr 12 07:33:00 GMT 2018
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85367
Bug ID: 85367
Summary: [GCOV] A call to the _subborrow_u64 builtin-function
is wrongly marked as executed twice
Product: gcc
Version: 8.0
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
8-20170923-1ubuntu2' --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
#include <x86intrin.h>
int main ()
{
unsigned char c;
unsigned long long x, y;
c = 0;
x = 1LL;
y = 0LL;
/* X = 0x0000000000000001, Y = 0x0000000000000000, C = 0. */
c = _subborrow_u64 (c, y, x, &x);
return 0;
}
$ gcc --coverage small.c; ./a.out; gcov-8 small.c; cat small.c.gcov
File 'small.c'
Lines executed:100.00% of 6
Creating 'small.c.gcov'
File '/usr/lib/gcc/x86_64-linux-gnu/8/include/adxintrin.h'
Lines executed:100.00% of 1
Creating 'adxintrin.h.gcov'
-: 0:Source:small.c
-: 0:Graph:small.gcno
-: 0:Data:small.gcda
-: 0:Runs:1
-: 0:Programs:1
-: 1:#include <x86intrin.h>
-: 2:
1: 3:int main ()
-: 4:{
-: 5: unsigned char c;
-: 6: unsigned long long x, y;
-: 7:
1: 8: c = 0;
1: 9: x = 1LL;
1: 10: y = 0LL;
-: 11:
-: 12: /* X = 0x0000000000000001, Y = 0x0000000000000000, C = 0. */
2: 13: c = _subborrow_u64 (c, y, x, &x);
-: 14:
1: 15: return 0;
-: 16:}
Line #13 is wrongly marked as executed twice.
Replacing _subborrow_u64 to _subborrow_u32, same problem.
I am not sure whether the problem is due to the value stored in the address &x
will be changed in _subborrow_u64.
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