[Bug c/38972] New: Failed constant folding and propagation in arithmetic expression.

[Bug c/38972] New: Failed constant folding and propagation in arithmetic expression.

[hironobu dot awazu at gmail dot com]

The following code is expected to print "1."
However, with -O1 or -O2 option, it prints "2." 
(-O0 option yields the correct output "1.")

--------------------------------------------
Source code:
   #include <stdio.h>

   int main (void)
   {
      int test=1;
      volatile int a = 1;

      test += (0 == a);         
      test += ((test + test) <= -69);

      printf("%d\n",test);

      return 0;
   }   
--------------------------------------------    
Compiler command line: "gcc -O1", "gcc -O2"
--------------------------------------------
Expected results: 1
--------------------------------------------
Observed results: 2
-------------------------------------------------------------
gcc -v output:
   Reading specs from /usr/lib/gcc/i686-pc-cygwin/3.4.4/specs
   Configured with:
   /usr/build/package/orig/test.respin/gcc-3.4.4-3/configure
   --verbose --prefix=/usr
   --exec-prefix=/usr --sysconfdir=/etc --libdir=/usr/lib
   --libexecdir=/usr/lib --mandir=/usr/share/man
   --infodir=/usr/share/info
   --enable-languages=c,ada,c++,d,f77,pascal,java,objc
   --enable-nls
   --without-included-gettext
   --enable-version-specific-runtime-libs --without-x
   --enable-libgcj --disable-java-awt
   --with-system-zlib --enable-interpreter
   --disable-libgcj-debug --enable-threads=posix
   --enable-java-gc=boehm
   --disable-win32-registry --enable-sjlj-exceptions
   --enable-hash-synchronization --enable-libstdcxx-debug
   Thread model: posix
   gcc version 3.4.4
   (cygming special, gdc 0.12, using dmd 0.125)
-------------------------------------------------------------


-- 
           Summary: Failed constant folding and propagation in arithmetic
                    expression.
           Product: gcc
           Version: 3.4.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hironobu dot awazu at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38972

[Bug c/38972] Failed constant folding and propagation in arithmetic expression.

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2009-01-26 10:24 -------
This is fixed in GCC 4.3.0 and later.  We probably have a duplicate bugreport
somewhere.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38972

[Bug c/38972] Failed constant folding and propagation in arithmetic expression.

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2009-01-26 19:06 -------
Reopening to ...


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|FIXED                       |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38972

[Bug middle-end/38972] Failed constant folding and propagation in arithmetic expression.

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2009-01-26 19:09 -------
To mark as fixed for 4.0.0.  This has been fixed for a while now.  Most likely
the gimplifier fixes it.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
          Component|c                           |middle-end
           Keywords|                            |wrong-code
      Known to work|                            |4.0.1
         Resolution|                            |FIXED
   Target Milestone|4.3.0                       |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38972