[Bug optimization/13299] New: Unsafe treatment of extended givs

[Bug optimization/13299] New: Unsafe treatment of extended givs

[rsandifo at gcc dot gnu dot org]

Loops of the form:

    void f (unsigned int *x)
    {
      unsigned char i;
      int j;

      i = 0x10;
      for (j = 0; j < 0x10; j++)
        {
          i += 0xe8;
          x[i] = 0;
          i -= 0xe7;
        }
    }

are miscompiled on x86 with -freduce-all-givs.  Complete gcc.dg-style
testcase attached.

-- 
           Summary: Unsafe treatment of extended givs
           Product: gcc
           Version: 3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rsandifo at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13299

[Bug optimization/13299] Unsafe treatment of extended givs

[rsandifo at gcc dot gnu dot org]

------- Additional Comments From rsandifo at gcc dot gnu dot org  2003-12-04 10:10 -------
Created an attachment (id=5272)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=5272&action=view)
Failing testcase


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13299

[Bug optimization/13299] Unsafe treatment of extended givs

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2003-12-04 10:48 -------
Confirmed. (The patch which would have fixed this has been withdrawn but lets hope this cane be 
fixed on the tree level with the tree-ssa but it needs a loop infrastructure first).

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2003-12-04 10:48:25
               date|                            |
   Target Milestone|---                         |tree-ssa


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13299

[Bug optimization/13299] Unsafe treatment of extended givs

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2003-12-04 15:23 -------
Links to the patch and some more information is here: 
  http://gcc.gnu.org/ml/gcc-patches/2003-12/msg00450.html 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13299

[Bug optimization/13299] Unsafe treatment of extended givs

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|tree-ssa                    |3.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13299

[Bug rtl-optimization/13299] Unsafe treatment of extended givs

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-06-21 01:13 -------
Hmm, I cannot reproduce this on the mainline with the example.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13299

[Bug rtl-optimization/13299] Unsafe treatment of extended givs

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.5.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13299

[Bug rtl-optimization/13299] Unsafe treatment of extended givs

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-01-06 19:11 -------
Subject: Bug 13299

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	rth@gcc.gnu.org	2005-01-06 19:10:57

Modified files:
	gcc            : ChangeLog loop.c 
Added files:
	gcc/testsuite/gcc.c-torture/execute: 20030916-1.c 

Log message:
	PR rtl-opt/13299
	* loop.c (get_monotonic_increment, biased_biv_fits_mode_p,
	biv_fits_mode_p, extension_within_bounds_p): New functions.
	(check_ext_dependent_givs): Use them.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.7048&r2=2.7049
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/loop.c.diff?cvsroot=gcc&r1=1.520&r2=1.521
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/20030916-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13299

[Bug rtl-optimization/13299] Unsafe treatment of extended givs

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-01-06 19:12 -------
Subject: Bug 13299

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-3_4-branch
Changes by:	rth@gcc.gnu.org	2005-01-06 19:12:05

Modified files:
	gcc            : ChangeLog loop.c 
Added files:
	gcc/testsuite/gcc.c-torture/execute: 20030916-1.c 20030916-1.x 

Log message:
	PR rtl-opt/13299
	* loop.c (get_monotonic_increment, biased_biv_fits_mode_p,
	biv_fits_mode_p, extension_within_bounds_p): New functions.
	(check_ext_dependent_givs): Use them.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=2.2326.2.762&r2=2.2326.2.763
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/loop.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.488.2.7&r2=1.488.2.8
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/20030916-1.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=NONE&r2=1.1.2.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/20030916-1.x.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=NONE&r2=1.1.2.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13299

[Bug rtl-optimization/13299] Unsafe treatment of extended givs

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-01-07 03:01 -------
Fixed for 3.4.4.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |3.4.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13299