[Bug middle-end/95326] GCC can not detect signed-integer-overflow correctly

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95326

Andrew Pinski  changed:

   What|Removed |Added

  Known to fail||13.1.0
  Known to work||12.3.0
 Resolution|--- |DUPLICATE
 Status|NEW |RESOLVED

--- Comment #5 from Andrew Pinski  ---
Fixed for GCC 13 by r13-4988-g8692b15ae7c05e so a dup of bug 108256.

*** This bug has been marked as a duplicate of bug 108256 ***

[Bug middle-end/95326] GCC can not detect signed-integer-overflow correctly

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95326

--- Comment #4 from Andrew Pinski  ---
(In reply to Haoxin Tu from comment #3)
> Would GCC shorten the multiple to be other types early as well? I also find
> some cases in "short" type with the same symptom. I am still testing now and
> don't know there are any cases in rest of types(such as char, int, long...)
> have the problem.

Yes and I suspect it is the same issue.  the shortening is happening in convert
before the instrumentation of the undefined sanitizer is done.

[Bug middle-end/95326] GCC can not detect signed-integer-overflow correctly

[haoxintu at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95326

--- Comment #3 from Haoxin Tu  ---
Would GCC shorten the multiple to be other types early as well? I also find
some cases in "short" type with the same symptom. I am still testing now and
don't know there are any cases in rest of types(such as char, int, long...)
have the problem.

By the way, should I file a new bug report when I found another type (for
example,int) that GCC can not detect the signed-integer-overflow UB issues?

[Bug middle-end/95326] GCC can not detect signed-integer-overflow correctly

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95326

Andrew Pinski  changed:

   What|Removed |Added

  Component|c++ |middle-end
   Last reconfirmed||2020-05-26
 Status|UNCONFIRMED |NEW
 Ever confirmed|0   |1

--- Comment #2 from Andrew Pinski  ---
The problem is GCC is shortening the multiple to be unsigned short early on.
That is doing:
long tt;
tt = l_volatile_uchar - l_var_short % g_const_uint * l_var_long;
l_var_short = tt;


Shows the issue.