[Bug c/35634] [avr] result of char promotion comes out of CHAR_MIN/MAX

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2008-03-19 10:23 -------
This is a bug in the C frontend which does the increment on type char, not
on the promoted type (I noticed that while fixing bitfield issues as well),
code in question is in build_unary_op() and this way since forever.

Original dump as from the FE:

;; Function main (main)
;; enabled by -tree-original

{ 
  char c;

    char c;
  c = 0;
  <D.1559>:; 
  foo ((int) c);
  c++ ;
  goto <D.1559>;
}

I tried to fix this once but failed.  Joseph - can you give this a shot?
The FE should for all pre-/postincrements just emit the proper
{( int res = x; x = (typeof x)((int)x + 1); res; )}
with using TARGET_EXPR/COMPOUND_EXPRs as required.

Note the C++ frontend has the same problem here, so transition that bug
there once the C FE is fixed.

Thanks.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jsm28 at gcc dot gnu dot org
             Status|UNCONFIRMED                 |NEW
          Component|target                      |c
     Ever Confirmed|0                           |1
           Keywords|                            |wrong-code
           Priority|P3                          |P1
   Last reconfirmed|0000-00-00 00:00:00         |2008-03-19 10:23:48
               date|                            |
   Target Milestone|---                         |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35634