* Re: scratch/igc 3f46110b878: Fix an eassert [not found] ` <20241211145532.114DD65A960@vcs3.savannah.gnu.org> @ 2024-12-11 15:09 ` Pip Cet via Emacs development discussions. 2024-12-11 15:36 ` Gerd Möllmann 0 siblings, 1 reply; 4+ messages in thread From: Pip Cet via Emacs development discussions. @ 2024-12-11 15:09 UTC (permalink / raw) To: emacs-devel; +Cc: Gerd M�llmann "Gerd Moellmann" <gerd@gnu.org> writes: > branch: scratch/igc > commit 3f46110b878ef0940ad7c0a9eacd6ef441baad7d > Author: Gerd Möllmann <gerd@gnu.org> > Commit: Gerd Möllmann <gerd@gnu.org> > > Fix an eassert > --- > src/igc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/src/igc.c b/src/igc.c > index b1ef6939b5f..2ce508e055e 100644 > --- a/src/igc.c > +++ b/src/igc.c > @@ -2223,7 +2223,7 @@ fix_weak_hash_table_weak_part (mps_ss_t ss, struct Lisp_Weak_Hash_Table_Weak_Par > for (ssize_t i = 0; i < limit; i++) > { > if (w->entries[i].intptr & 1) > - eassert ((mps_word_t)w->entries[i].intptr ^ w->entries[i].intptr == 0); > + eassert ((mps_word_t)w->entries[i].intptr ^ (w->entries[i].intptr == 0)); > bool was_nil = (w->entries[i].intptr) == 0; > intptr_t off = 0; > #ifdef WORDS_BIGENDIAN I'm guessing I'm failing a basic C knowledge test here, but can you explain? Did you run into an assertion error with the old code, or a compiler warning? The intended assertion was that if the .intptr component is truncated to mps_word_t size, no information is lost, because I saw some problems with "negative" 32-bit addresses filling the MSB 32 bits of the Lisp_Objects with ones (the sign extension/zero extension problem, in other words). That would lead to the "splatted" Lisp_Object reading as 0xffffffff00000000, which caused trouble. So on i386, the assertion could also be written as (w->entries[i].intptr & 0xffffffff00000000) == 0 I think the "fixed" assertion is trivially true? Pip ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: scratch/igc 3f46110b878: Fix an eassert 2024-12-11 15:09 ` scratch/igc 3f46110b878: Fix an eassert Pip Cet via Emacs development discussions. @ 2024-12-11 15:36 ` Gerd Möllmann 2024-12-11 15:40 ` Gerd Möllmann 0 siblings, 1 reply; 4+ messages in thread From: Gerd Möllmann @ 2024-12-11 15:36 UTC (permalink / raw) To: Pip Cet; +Cc: emacs-devel, Gerd M�llmann Pip Cet <pipcet@protonmail.com> writes: > "Gerd Moellmann" <gerd@gnu.org> writes: > >> branch: scratch/igc >> commit 3f46110b878ef0940ad7c0a9eacd6ef441baad7d >> Author: Gerd Möllmann <gerd@gnu.org> >> Commit: Gerd Möllmann <gerd@gnu.org> >> >> Fix an eassert >> --- >> src/igc.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/src/igc.c b/src/igc.c >> index b1ef6939b5f..2ce508e055e 100644 >> --- a/src/igc.c >> +++ b/src/igc.c >> @@ -2223,7 +2223,7 @@ fix_weak_hash_table_weak_part (mps_ss_t ss, struct Lisp_Weak_Hash_Table_Weak_Par >> for (ssize_t i = 0; i < limit; i++) >> { >> if (w->entries[i].intptr & 1) >> - eassert ((mps_word_t)w->entries[i].intptr ^ w->entries[i].intptr == 0); >> + eassert ((mps_word_t)w->entries[i].intptr ^ (w->entries[i].intptr == 0)); >> bool was_nil = (w->entries[i].intptr) == 0; >> intptr_t off = 0; >> #ifdef WORDS_BIGENDIAN > > I'm guessing I'm failing a basic C knowledge test here, but can you > explain? Did you run into an assertion error with the old code, or a > compiler warning? It was a warning from clang. So the right thing would be (x ^ y) == 0? ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: scratch/igc 3f46110b878: Fix an eassert 2024-12-11 15:36 ` Gerd Möllmann @ 2024-12-11 15:40 ` Gerd Möllmann 2024-12-11 15:55 ` Gerd Möllmann 0 siblings, 1 reply; 4+ messages in thread From: Gerd Möllmann @ 2024-12-11 15:40 UTC (permalink / raw) To: Pip Cet; +Cc: emacs-devel, Gerd M�llmann Gerd Möllmann <gerd.moellmann@gmail.com> writes: > Pip Cet <pipcet@protonmail.com> writes: > >> "Gerd Moellmann" <gerd@gnu.org> writes: >> >>> branch: scratch/igc >>> commit 3f46110b878ef0940ad7c0a9eacd6ef441baad7d >>> Author: Gerd Möllmann <gerd@gnu.org> >>> Commit: Gerd Möllmann <gerd@gnu.org> >>> >>> Fix an eassert >>> --- >>> src/igc.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/src/igc.c b/src/igc.c >>> index b1ef6939b5f..2ce508e055e 100644 >>> --- a/src/igc.c >>> +++ b/src/igc.c >>> @@ -2223,7 +2223,7 @@ fix_weak_hash_table_weak_part (mps_ss_t ss, struct Lisp_Weak_Hash_Table_Weak_Par >>> for (ssize_t i = 0; i < limit; i++) >>> { >>> if (w->entries[i].intptr & 1) >>> - eassert ((mps_word_t)w->entries[i].intptr ^ w->entries[i].intptr == 0); >>> + eassert ((mps_word_t)w->entries[i].intptr ^ (w->entries[i].intptr == 0)); >>> bool was_nil = (w->entries[i].intptr) == 0; >>> intptr_t off = 0; >>> #ifdef WORDS_BIGENDIAN >> >> I'm guessing I'm failing a basic C knowledge test here, but can you >> explain? Did you run into an assertion error with the old code, or a >> compiler warning? > > It was a warning from clang. So the right thing would be (x ^ y) == 0? So thi sone? odified src/igc.c @@ -2278,7 +2278,7 @@ fix_weak_hash_table_weak_part (mps_ss_t ss, struct Lisp_Weak_Hash_Table_Weak_Par for (ssize_t i = 0; i < limit; i++) { if (w->entries[i].intptr & 1) - eassert ((mps_word_t)w->entries[i].intptr ^ (w->entries[i].intptr == 0)); + eassert (((mps_word_t)w->entries[i].intptr ^ w->entries[i].intptr) == 0); bool was_nil = (w->entries[i].intptr) == 0; intptr_t off = 0; #ifdef WORDS_BIGENDIAN ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: scratch/igc 3f46110b878: Fix an eassert 2024-12-11 15:40 ` Gerd Möllmann @ 2024-12-11 15:55 ` Gerd Möllmann 0 siblings, 0 replies; 4+ messages in thread From: Gerd Möllmann @ 2024-12-11 15:55 UTC (permalink / raw) To: Pip Cet; +Cc: emacs-devel, Gerd M�llmann Gerd Möllmann <gerd.moellmann@gmail.com> writes: > Gerd Möllmann <gerd.moellmann@gmail.com> writes: > >> Pip Cet <pipcet@protonmail.com> writes: >> >>> "Gerd Moellmann" <gerd@gnu.org> writes: >>> >>>> branch: scratch/igc >>>> commit 3f46110b878ef0940ad7c0a9eacd6ef441baad7d >>>> Author: Gerd Möllmann <gerd@gnu.org> >>>> Commit: Gerd Möllmann <gerd@gnu.org> >>>> >>>> Fix an eassert >>>> --- >>>> src/igc.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/src/igc.c b/src/igc.c >>>> index b1ef6939b5f..2ce508e055e 100644 >>>> --- a/src/igc.c >>>> +++ b/src/igc.c >>>> @@ -2223,7 +2223,7 @@ fix_weak_hash_table_weak_part (mps_ss_t ss, struct Lisp_Weak_Hash_Table_Weak_Par >>>> for (ssize_t i = 0; i < limit; i++) >>>> { >>>> if (w->entries[i].intptr & 1) >>>> - eassert ((mps_word_t)w->entries[i].intptr ^ w->entries[i].intptr == 0); >>>> + eassert ((mps_word_t)w->entries[i].intptr ^ (w->entries[i].intptr == 0)); >>>> bool was_nil = (w->entries[i].intptr) == 0; >>>> intptr_t off = 0; >>>> #ifdef WORDS_BIGENDIAN >>> >>> I'm guessing I'm failing a basic C knowledge test here, but can you >>> explain? Did you run into an assertion error with the old code, or a >>> compiler warning? >> >> It was a warning from clang. So the right thing would be (x ^ y) == 0? > > So thi sone? > > odified src/igc.c > @@ -2278,7 +2278,7 @@ fix_weak_hash_table_weak_part (mps_ss_t ss, struct Lisp_Weak_Hash_Table_Weak_Par > for (ssize_t i = 0; i < limit; i++) > { > if (w->entries[i].intptr & 1) > - eassert ((mps_word_t)w->entries[i].intptr ^ (w->entries[i].intptr == 0)); > + eassert (((mps_word_t)w->entries[i].intptr ^ w->entries[i].intptr) == 0); > bool was_nil = (w->entries[i].intptr) == 0; > intptr_t off = 0; > #ifdef WORDS_BIGENDIAN Please ignore, this was already fixed, I didn't see it. ^ permalink raw reply [flat|nested] 4+ messages in thread
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[not found] ` <20241211145532.114DD65A960@vcs3.savannah.gnu.org>
2024-12-11 15:09 ` scratch/igc 3f46110b878: Fix an eassert Pip Cet via Emacs development discussions.
2024-12-11 15:36 ` Gerd Möllmann
2024-12-11 15:40 ` Gerd Möllmann
2024-12-11 15:55 ` Gerd Möllmann
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