[Bug c/31691] New: optimized code taking the wrong branch

[Bug c/31691] New: optimized code taking the wrong branch

[stephaniechc-gccbug at yahoo dot com]

The following example takes the "wrong_branch" when compiled with 
    gcc -O3 -fno-inline

gcc --version
gcc (GCC) 4.1.2
Copyright (C) 2006 Free Software Foundation, Inc.

===== example =====
#include <stdio.h>

static int get_kind(int v) {
    volatile int k = v;
    return k;
}

static int some_call(void)
{
    return 0;
}

static void wrong_branch(void) {
    printf("wrong_branch\n");
}

static int example(int arg)
{
    int  kind;
    kind = get_kind(arg);
    if (kind == 9 || kind == 10 || kind == 5) {
        if (some_call() == 0) {
            int tmp;
//            kind = get_kind(arg); // ok if this call is inserted
            if (kind == 9 || kind == 10) {
                tmp = arg;
            } else {
                wrong_branch();
            } /* if */
            return 0;
        }
    }
    return 0;
} 

int main(void) {
    int v = 10;
    example(v);
    return 0;
}

===================

The example prints "wrong_branch" when executed. If the second call to get_kind
is uncommented, nothing is printed (which is correct).

The generated assembly code is

===== example.s ======
example:
        save    %sp, -112, %sp
        call    get_kind, 0
         mov    %i0, %o0
        add     %o0, -9, %g1
        subcc   %g0, %g1, %g0
        subx    %g0, -1, %i0
        cmp     %g1, 1
        bleu    .LL11
         cmp    %o0, 5
        be      .LL11
         nop
.LL9:
        jmp     %i7+8
         restore %g0, 0, %o0
.LL11:
        call    some_call, 0
         nop
        cmp     %o0, 0
        bne     .LL9
         cmp    %i0, 0
        bne     .LL9
         nop
        call    wrong_branch, 0
         mov    0, %i0
        jmp     %i7+8
         restore
=======================


-- 
           Summary: optimized code taking the wrong branch
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: stephaniechc-gccbug at yahoo dot com
 GCC build triplet: sparc-sun-solaris2.8
  GCC host triplet: sparc-sun-solaris2.8+
GCC target triplet: sparc-sun-solaris2.8+


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug middle-end/31691] optimized code taking the wrong branch

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2007-04-25 09:53 -------
Works for me.  Can you attach the FILE.c.t93.optimized file you get if you
build with gcc -O3 -fno-inline -fdump-tree-optimized?


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug middle-end/31691] [4.1 regression] optimized code taking the wrong branch

[ebotcazou at gcc dot gnu dot org]

------- Comment #2 from ebotcazou at gcc dot gnu dot org  2007-04-25 11:14 -------
Confirmed with -O2 -fno-inline too, thanks for the reduced testcase.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
     Ever Confirmed|0                           |1
   GCC host triplet|sparc-sun-solaris2.8+       |sparc-sun-solaris2.8
 GCC target triplet|sparc-sun-solaris2.8+       |sparc-sun-solaris2.8
      Known to fail|                            |4.1.2
      Known to work|                            |3.4.3 4.2.0 4.3.0
   Last reconfirmed|0000-00-00 00:00:00         |2007-04-25 11:14:17
               date|                            |
            Summary|optimized code taking the   |[4.1 regression] optimized
                   |wrong branch                |code taking the wrong branch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug middle-end/31691] [4.1 regression] optimized code taking the wrong branch

[ebotcazou at gcc dot gnu dot org]

------- Comment #3 from ebotcazou at gcc dot gnu dot org  2007-04-25 11:14 -------
Investigating.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |ebotcazou at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2007-04-25 11:14:17         |2007-04-25 11:14:55
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug middle-end/31691] [4.1 regression] optimized code taking the wrong branch

[stephaniechc-gccbug at yahoo dot com]

------- Comment #4 from stephaniechc-gccbug at yahoo dot com  2007-04-25 14:26 -------
Created an attachment (id=13438)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13438&action=view)
output of -fdump-tree-optimized


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug rtl-optimization/31691] [4.1 regression] optimized code taking the wrong branch

[ebotcazou at gcc dot gnu dot org]

------- Comment #5 from ebotcazou at gcc dot gnu dot org  2007-04-26 11:28 -------
It's again the RTL combiner.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|middle-end                  |rtl-optimization


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug rtl-optimization/31691] [4.1 regression] optimized code taking the wrong branch

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
   Target Milestone|---                         |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug rtl-optimization/31691] [4.1 regression] optimized code taking the wrong branch

[ebotcazou at gcc dot gnu dot org]

------- Comment #6 from ebotcazou at gcc dot gnu dot org  2007-05-10 12:16 -------
*** Bug 31523 has been marked as a duplicate of this bug. ***


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |anirkko at insel dot ch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug rtl-optimization/31691] [4.1 regression] optimized code taking the wrong branch

[ebotcazou at gcc dot gnu dot org]

------- Comment #7 from ebotcazou at gcc dot gnu dot org  2007-05-10 20:30 -------
Created an attachment (id=13540)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13540&action=view)
Fix for the 4.1 branch.

I'm waiting for the 4.2 branch to reopen in order to install it on all
branches.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug rtl-optimization/31691] [4.1 regression] optimized code taking the wrong branch

[ebotcazou at gcc dot gnu dot org]

------- Comment #9 from ebotcazou at gcc dot gnu dot org  2007-05-17 14:30 -------
Subject: Bug 31691

Author: ebotcazou
Date: Thu May 17 13:29:38 2007
New Revision: 124798

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=124798
Log:
        PR rtl-optimization/31691
        * combine.c (simplify_set): Build a new src pattern instead of
        substituting its operands in the COMPARE case.


Added:
    branches/gcc-4_2-branch/gcc/testsuite/gcc.c-torture/execute/20070517-1.c
Modified:
    branches/gcc-4_2-branch/gcc/ChangeLog
    branches/gcc-4_2-branch/gcc/combine.c
    branches/gcc-4_2-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug rtl-optimization/31691] [4.1 regression] optimized code taking the wrong branch

[ebotcazou at gcc dot gnu dot org]

------- Comment #8 from ebotcazou at gcc dot gnu dot org  2007-05-17 14:29 -------
Subject: Bug 31691

Author: ebotcazou
Date: Thu May 17 13:29:10 2007
New Revision: 124797

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=124797
Log:
        PR rtl-optimization/31691
        * combine.c (simplify_set): Build a new src pattern instead of
        substituting its operands in the COMPARE case.


Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/20070517-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/combine.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug rtl-optimization/31691] [4.1 regression] optimized code taking the wrong branch

[ebotcazou at gcc dot gnu dot org]

------- Comment #10 from ebotcazou at gcc dot gnu dot org  2007-05-17 14:30 -------
Subject: Bug 31691

Author: ebotcazou
Date: Thu May 17 13:30:15 2007
New Revision: 124799

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=124799
Log:
        PR rtl-optimization/31691
        * combine.c (simplify_set): Build a new src pattern instead of
        substituting its operands in the COMPARE case.


Added:
    branches/gcc-4_1-branch/gcc/testsuite/gcc.c-torture/execute/20070517-1.c
Modified:
    branches/gcc-4_1-branch/gcc/ChangeLog
    branches/gcc-4_1-branch/gcc/combine.c
    branches/gcc-4_1-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691

[Bug rtl-optimization/31691] [4.1 regression] optimized code taking the wrong branch

[ebotcazou at gcc dot gnu dot org]

------- Comment #11 from ebotcazou at gcc dot gnu dot org  2007-05-17 14:34 -------
Fixed on all branches.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2007-
                   |                            |05/msg01131.html
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691