https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82527
Martin Liška <marxin at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution|--- |INVALID
--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Thanks for the issue. Note that order of branches which go from switch
statement to corresponding case labels is not ordered.
With new GCC 8.1, we'll come up with '-w' option. Then you'll see the
connections (edges):
$ rm *.gcda && gcc pr82527.c --coverage && ./a.out && gcov -abw pr82527.c &&
cat pr82527.c.gcov
0dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddFile
'pr82527.c'
Lines executed:83.33% of 12
Branches executed:100.00% of 5
Taken at least once:80.00% of 5
No calls
Creating 'pr82527.c.gcov'
-: 0:Source:pr82527.c
-: 0:Graph:pr82527.gcno
-: 0:Data:pr82527.gcda
-: 0:Runs:1
-: 0:Programs:1
-: 1:#include <stdio.h>
-: 2:int
function main called 1 returned 100% blocks executed 91%
1: 3:main ()
-: 4:{
101: 5: for (int i = 0; i < 100; i++)
1: 5-block 0 (BB 2)
100: 5-block 1 (BB 9)
101: 5-block 2 (BB 10)
branch 0 taken 99% (BB 3)
branch 1 taken 1% (fallthrough) (BB 11)
-: 6: {
100: 7: switch (i)
100: 7-block 0 (BB 3)
branch 0 taken 1% (BB 4)
branch 1 taken 0% (BB 6)
branch 2 taken 99% (BB 7)
-: 8: {
1: 9: case 0:
1: 10: printf ("0");
1: 10-block 0 (BB 4)
call 0 returned 100%
1: 11: break;
#####: 12: case 9999:
#####: 13: break;
$$$$$: 13-block 0 (BB 6)
99: 14: default:
99: 15: printf ("d");
99: 15-block 0 (BB 7)
call 0 returned 100%
99: 16: break;
-: 17: }
-: 18: }
1: 19: return 0;
1: 19-block 0 (BB 11)
-: 20:}
$ rm *.gcda && gcc -O3 pr82527.c --coverage && ./a.out && gcov -abw pr82527.c
&& cat pr82527.c.gcov
0dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddFile
'pr82527.c'
Lines executed:100.00% of 9
Branches executed:100.00% of 4
Taken at least once:75.00% of 4
No calls
Creating 'pr82527.c.gcov'
-: 0:Source:pr82527.c
-: 0:Graph:pr82527.gcno
-: 0:Data:pr82527.gcda
-: 0:Runs:1
-: 0:Programs:1
-: 1:#include <stdio.h>
-: 2:int
function main called 1 returned 100% blocks executed 100%
1: 3:main ()
-: 4:{
101: 5: for (int i = 0; i < 100; i++)
1: 5-block 0 (BB 2)
100: 5-block 1 (BB 8)
101: 5-block 2 (BB 9)
branch 0 taken 99% (BB 3)
branch 1 taken 1% (fallthrough) (BB 10)
-: 6: {
100: 7: switch (i)
100: 7-block 0 (BB 3)
branch 0 taken 1% (BB 4)
branch 1 taken 99% (BB 6)
branch 2 taken 0% (BB 8)
-: 8: {
1: 9: case 0:
1: 10: printf ("0");
1: 10-block 0 (BB 4)
call 0 returned 100%
1: 11: break;
-: 12: case 9999:
-: 13: break;
99: 14: default:
99: 15: printf ("d");
99: 15-block 0 (BB 6)
call 0 returned 100%
99: 16: break;
-: 17: }
-: 18: }
-: 19: return 0;
-: 20:}
And you're right w/ -O3 it goes to a different BB and order is changed.
Hope it will help you? I'm closing it as invalid.
