https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90420
--- Comment #6 from Yibiao Yang <yangyibiao at nju dot edu.cn> ---
(In reply to Martin Liška from comment #1)
> > $ gcc -O3 -g --coverage small.c; ./a.out; gcov small.c; cat small.c.gcov
> > File 'small.c'
> > Lines executed:78.57% of 14
> > Creating 'small.c.gcov'
> >
> > -: 0:Source:small.c
> > -: 0:Graph:small.gcno
> > -: 0:Data:small.gcda
> > -: 0:Runs:1
> > -: 1:#define N 1000
> > -: 2:
> > -: 3:int argc = 1;
> > -: 4:
> > #####: 5:int func (int *p, int *q) {
> > 1001*: 6: int x = 0;
> > #####: 7: for (int i = 0; i < N; i++) {
> > 1000*: 8: x += (q[i] + p[i]);
> > -: 9: }
> > 1*: 10: return x;
> > -: 11:}
> > -: 12:
> > 1: 13:int main ()
> > -: 14:{
> > 1: 15: int x = 0;
> > 1: 16: int A1[N], A2[N];
> > -: 17:
> > 1001: 18: for (int i = 0; i < N; i++) {
> > 1000: 19: A1[i] = 5 + argc;
> > 1000: 20: A2[i] = 1;
> > -: 21: }
> > -: 22:
> > 1001: 23: x = func (A1, A2);
> > -: 24:
> > 1: 25: if (x != N * 7)
> > #####: 26: return 1;
> > -: 27:
> > -: 28: return 0;
> > -: 29:}
> >
> >
> > When using "-O3" optimization, Line #6 and Line #22 are wrongly marked as
>
> I can't see Line #22 being executed.
>
> With 9.1.0 I see:
>
> -: 0:Source:pr90420.c
> -: 0:Graph:pr90420.gcno
> -: 0:Data:pr90420.gcda
> -: 0:Runs:1
> -: 1:#define N 1000
> -: 2:
> -: 3:int argc = 1;
> -: 4:
> #####: 5:int func (int *p, int *q) {
> -: 6: int x = 0;
> 1001*: 7: for (int i = 0; i < N; i++) {
> 1000*: 8: x += (q[i] + p[i]);
> -: 9: }
> #####: 10: return x;
> -: 11:}
> -: 12:
> 1: 13:int main ()
> -: 14:{
> -: 15: int x = 0;
> -: 16: int A1[N], A2[N];
> -: 17:
> 1001: 18: for (int i = 0; i < N; i++) {
> 1000: 19: A1[i] = 5 + argc;
> 1000: 20: A2[i] = 1;
> -: 21: }
> -: 22:
> -: 23: x = func (A1, A2);
> -: 24:
> 1: 25: if (x != N * 7)
> #####: 26: return 1;
> -: 27:
> -: 28: return 0;
> -: 29:}
>
> which should be reasonable good.
of this code :
#####: 5:int func (int *p, int *q) {
-: 6: int x = 0;
1001*: 7: for (int i = 0; i < N; i++) {
1000*: 8: x += (q[i] + p[i]);
-: 9: }
#####: 10: return x;
-: 11:}
Line #5 is marked as not executed. I understand that this function might be
optimized as an inline function. However, since Line #7 and Line #8 is marked
as executed and Line #5 is marked as not executed. This might mislead others
when debugging or testing based on code coverage.
