[Bug target/30665] New: peephole2 misapplied on postinc mem

[Bug target/30665] New: peephole2 misapplied on postinc mem

[hp at gcc dot gnu dot org]

This testcase is miscompiled on all versions of GCC (visible on r111226):
int  __attribute__ ((__noinline__)) f (unsigned *p, int *x)
{
  int y = *p++ & 0xfff;
  *x++ = y;
  *x = *p;
  return y;
}

int main (void)
{
  unsigned u[2] = { 0xbaad, 0xdad1 };
  int x[2] = {17689, 23456};

  if (f (u, x) != 0xaad || x[0] != 0xaad || x[1] != 0xdad1)
    abort ();
  exit (0);
}

It's caused by the cris.md peephole2 marked "andu (casesi+45)" allowing
post-inc memory in operand 1, effectively "shrinking" the post-inc.
The fix is to replace all "(GET_CODE (operands[1]) != MEM || ! MEM_VOLATILE_P
(operands[1]))" with "!side_effects_p (operands[1])" everywhere.


-- 
           Summary: peephole2 misapplied on postinc mem
           Product: gcc
           Version: 3.2.1
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: hp at gcc dot gnu dot org
        ReportedBy: hp at gcc dot gnu dot org
GCC target triplet: cris-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30665

[Bug target/30665] peephole2 misapplied on postinc mem

[hp at gcc dot gnu dot org]

-- 

hp at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-02-01 11:35:32
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30665

[Bug target/30665] peephole2 misapplied on postinc mem

[hp at gcc dot gnu dot org]

------- Comment #1 from hp at gcc dot gnu dot org  2007-02-05 21:20 -------
Subject: Bug 30665

Author: hp
Date: Mon Feb  5 21:20:36 2007
New Revision: 121611

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=121611
Log:
        PR target/30665
        * gcc.dg/torture/pr30665-1.c, gcc.dg/torture/pr30665-2.c: New tests.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr30665-1.c
    trunk/gcc/testsuite/gcc.dg/torture/pr30665-2.c
Modified:
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30665

[Bug target/30665] peephole2 misapplied on postinc mem

[hp at gcc dot gnu dot org]

------- Comment #2 from hp at gcc dot gnu dot org  2007-02-05 21:22 -------
Subject: Bug 30665

Author: hp
Date: Mon Feb  5 21:22:24 2007
New Revision: 121613

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=121613
Log:
        PR target/30665
        * config/cris/cris.md ("*andsi_movu", "*andsi_clear", "*andhi_movu")
        ("*andhi_clear", andu (casesi+45)): For size-changed operand where
        memory is allowed, require !side_effects_p, not just !MEM_VOLATILE_P.

Modified:
    trunk/gcc/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30665

[Bug target/30665] peephole2 misapplied on postinc mem

[hp at gcc dot gnu dot org]

------- Comment #3 from hp at gcc dot gnu dot org  2007-02-05 21:44 -------
Might be worthwhile to import this to other branches, but closing with 4.3
milestone for now.


-- 

hp at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30665