https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90420
Martin Liška <marxin at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |WAITING
Last reconfirmed| |2019-05-10
Ever confirmed|0 |1
--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
> $ 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.
