[1/2] gcov: test switch/break line counts
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Commit Message
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.
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(-)
Comments
Hello,
On Tue, 11 Oct 2022, 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.
>
> 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;
> - }
> +
Assuming this is correct (I really can't say) then the comment needs
adjustments. It specifically talks about this very code you remove.
Ciao,
Michael.
On 11/10/2022 15:55, Michael Matz wrote:
> Hello,
>
> On Tue, 11 Oct 2022, 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.
>>
>> 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;
>> - }
>> +
>
> Assuming this is correct (I really can't say) then the comment needs
> adjustments. It specifically talks about this very code you remove.
>
>
> Ciao,
> Michael.
Michael,
I apologise for the confusion. The diff there is not a part of the change itself
(note the indentation) but rather a way to reproduce, or at least understand,
the type of change that would trigger the new test error. If it is too confusing
I can re-write the commit message.
Thanks,
Jørgen
Hello,
On Tue, 11 Oct 2022, Jørgen Kvalsvik wrote:
> I apologise for the confusion. The diff there is not a part of the
> change itself (note the indentation) but rather a way to reproduce,
Ah! Thanks, that explains it, sorry for adding confusion on top :-)
Ciao,
Michael.
On Tue, Oct 11, 2022 at 2:43 PM Jørgen Kvalsvik
<jorgen.kvalsvik@woven-planet.global> 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.
>
> 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:
OK.
Thanks,
Richard.
>
> * 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) */
> --
> 2.34.0
>
On 13/10/2022 13:39, Richard Biener wrote:
> On Tue, Oct 11, 2022 at 2:43 PM Jørgen Kvalsvik
> <jorgen.kvalsvik@woven-planet.global> 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.
>>
>> 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:
>
> OK.
>
> Thanks,
> Richard.
>
>>
>> * 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) */
>> --
>> 2.34.0
>>
Thank you, I've installed the patches.
I noticed that the inclusion of diffs in the message works fine with git
generally, but could be picked up on by git format-patch && git am < patch. I
hope that does not end up causing too many problems (last time, promise!)
Thanks,
Jørgen
@@ -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) */
@@ -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) */