Re: [PATCH 1/2] gcov: test switch/break line counts

["Martin Liška" <mliska@suse.cz>]

On 10/5/22 14:04, Jørgen Kvalsvik via Gcc-patches wrote:
> The coverage support will under some conditions decide to split edges to
> accurately report coverage. By running the test suite with/without this
> edge splitting a small diff shows up, addressed by this patch, which
> should catch future regressions.

Thanks for the patch, it's OK (please apply it).

Martin

> 
> Removing the edge splitting:
> 
> diff --git a/gcc/profile.cc b/gcc/profile.cc
> --- a/gcc/profile.cc
> +++ b/gcc/profile.cc
> @@ -1244,19 +1244,7 @@ branch_prob (bool thunk)
>                 Don't do that when the locuses match, so
>                 if (blah) goto something;
>                 is not computed twice.  */
> -             if (last
> -                 && gimple_has_location (last)
> -                 && !RESERVED_LOCATION_P (e->goto_locus)
> -                 && !single_succ_p (bb)
> -                 && (LOCATION_FILE (e->goto_locus)
> -                     != LOCATION_FILE (gimple_location (last))
> -                     || (LOCATION_LINE (e->goto_locus)
> -                         != LOCATION_LINE (gimple_location (last)))))
> -               {
> -                 basic_block new_bb = split_edge (e);
> -                 edge ne = single_succ_edge (new_bb);
> -                 ne->goto_locus = e->goto_locus;
> -               }
> +
>         if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
>                 && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
>                 need_exit_edge = 1;
> 
> Assuming the .gcov files from make chec-gcc RUNTESTFLAGS=gcov.exp are
> kept:
> 
> $ diff -r no-split-edge with-split-edge | grep -C 2 -E "^[<>]\s\s"
> diff -r sans-split-edge/gcc/gcov-4.c.gcov with-split-edge/gcc/gcov-4.c.gcov
>    228c228
>    <         -:  224:        break;
>    ---
>    >         1:  224:        break;
>    231c231
>    <         -:  227:        break;
>    ---
>    >     #####:  227:        break;
>    237c237
>    <         -:  233:        break;
>    ---
>    >         2:  233:        break;
> 
> gcc/testsuite/ChangeLog:
> 
> 	* g++.dg/gcov/gcov-1.C: Add line count check.
> 	* gcc.misc-tests/gcov-4.c: Likewise.
> ---
>  gcc/testsuite/g++.dg/gcov/gcov-1.C    | 8 ++++----
>  gcc/testsuite/gcc.misc-tests/gcov-4.c | 4 ++--
>  2 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/gcc/testsuite/g++.dg/gcov/gcov-1.C b/gcc/testsuite/g++.dg/gcov/gcov-1.C
> index 9018b9a3a73..ee383b480a8 100644
> --- a/gcc/testsuite/g++.dg/gcov/gcov-1.C
> +++ b/gcc/testsuite/g++.dg/gcov/gcov-1.C
> @@ -257,20 +257,20 @@ test_switch (int i, int j)
>    switch (i)				/* count(5) */
>  					/* branch(end) */
>      {
> -      case 1:
> +      case 1:				/* count(1) */
>          result = do_something (2);	/* count(1) */
> -        break;
> +        break;				/* count(1) */
>        case 2:
>          result = do_something (1024);
>          break;
> -      case 3:
> +      case 3:				/* count(3) */
>        case 4:
>  					/* branch(67) */
>          if (j == 2)			/* count(3) */
>  					/* branch(end) */
>            return do_something (4);	/* count(1) */
>          result = do_something (8);	/* count(2) */
> -        break;
> +        break;				/* count(2) */
>        default:
>  	result = do_something (32);	/* count(1) */
>  	switch_m++;			/* count(1) */
> diff --git a/gcc/testsuite/gcc.misc-tests/gcov-4.c b/gcc/testsuite/gcc.misc-tests/gcov-4.c
> index 9d8ab1c1097..498d299b66b 100644
> --- a/gcc/testsuite/gcc.misc-tests/gcov-4.c
> +++ b/gcc/testsuite/gcc.misc-tests/gcov-4.c
> @@ -221,7 +221,7 @@ test_switch (int i, int j)
>      {
>        case 1:
>          result = do_something (2);	/* count(1) */
> -        break;
> +        break;				/* count(1) */
>        case 2:
>          result = do_something (1024);
>          break;
> @@ -230,7 +230,7 @@ test_switch (int i, int j)
>          if (j == 2)			/* count(3) */
>            return do_something (4);	/* count(1) */
>          result = do_something (8);	/* count(2) */
> -        break;
> +        break;				/* count(2) */
>        default:
>  	result = do_something (32);	/* count(1) */
>  	switch_m++;			/* count(1) */