[Bug tree-optimization/23049] New: ICE with -O3 -ftree-vectorize on 4.1.x

[Bug tree-optimization/23049] New: ICE with -O3 -ftree-vectorize on 4.1.x

[drab at kepler dot fjfi dot cvut dot cz]

The example (attached below), when compiled by following gcc

-------------------
$ gcc -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: ../../../gcc-CVS-20050723/gcc-CVS-20050723/configure
--host=i686-pc-linux-gnu --prefix=/usr/local/opt/gcc-4.1
--exec-prefix=/usr/local/opt/gcc-4.1 --sysconfdir=/etc
--libdir=/usr/local/opt/gcc-4.1/lib --libexecdir=/usr/local/opt/gcc-4.1/libexec
--sharedstatedir=/var --localstatedir=/var --program-suffix=-4.1
--with-x-includes=/usr/X11R6/include --with-x-libraries=/usr/X11R6/lib
--enable-shared --enable-static --with-gnu-as --with-gnu-ld --with-stabs
--enable-threads=posix --enable-version-specific-runtime-libs --disable-coverage
--disable-libgcj --disable-checking --enable-multilib --with-x --enable-cmath
--enable-libstdcxx-debug --enable-fast-character --enable-hash-synchronization
--with-system-zlib --with-libbanshee --with-demangler-in-ld
--with-arch=athlon-xp --enable-libada --enable-languages=c,c++,f95,objc,ada
Thread model: posix
gcc version 4.1.0 20050723 (experimental)
---------------------

with

---------------------
gcc -O3 -ftree-vectorize -c -o ac3enc.o ac3enc.c
---------------------

results in this:

---------------------
gcc: Internal error: Segmentation fault (program cc1)
Please submit a full bug report.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
---------------------

Tested on both i686-pc-linux-gnu and x86_64-pc-linux-gnu with the same result.

With -O2 -ftree-vectorize it compiles without problem.
Also gcc version 4.0.1 20050630 (prerelease) seems to take it without problems.

-- 
           Summary: ICE with -O3 -ftree-vectorize on 4.1.x
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: drab at kepler dot fjfi dot cvut dot cz
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: i?86-*-*, x86_64-*-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] ICE with -O3 -ftree-vectorize on 4.1.x

[drab at kepler dot fjfi dot cvut dot cz]

------- Additional Comments From drab at kepler dot fjfi dot cvut dot cz  2005-07-24 14:23 -------
Created an attachment (id=9343)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=9343&action=view)
Triggers the problem


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] ICE with -O3 -ftree-vectorize on 4.1.x

[drab at kepler dot fjfi dot cvut dot cz]

------- Additional Comments From drab at kepler dot fjfi dot cvut dot cz  2005-07-24 14:24 -------
It doesn't seem to be related to the Bug 23048 to me, so i reported it separately.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] ICE with -O3 -ftree-vectorize on 4.1.x

[drab at kepler dot fjfi dot cvut dot cz]

------- Additional Comments From drab at kepler dot fjfi dot cvut dot cz  2005-07-24 14:32 -------
Created an attachment (id=9344)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=9344&action=view)
Seems to trigger the same problem

The behaviour is exactly the same as with my first example, so I'm adding this
just for completness. Although, it could also be a different bug that just
gives the same visible result for me.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-24 14:57 -------
Reducing the first one.  It is a stack overflow.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
           Severity|critical                    |normal
           Keywords|                            |ice-on-valid-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |4.1.0
      Known to work|                            |4.0.0
            Summary|ICE with -O3 -ftree-        |[4.1 Regression] ICE with -
                   |vectorize on 4.1.x          |O3 -ftree-vectorize on 4.1.x


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-24 15:37 -------
Reduced testcase for the first one:
static unsigned short int crc_table[256];
void AC3_encode_init(void)
{
  unsigned int c, n, k;
  for(n=0;  n<256; n++)
  {
    c = n << 8;
    for (k = 0; k < 8; k++)
    {
      if (c & (1 << 15))
       c = ((c << 1) & 0xffff) ^ (((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16)) & 0xffff);
    }
    crc_table[n] = c;
  }
}


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-07-24 15:37:30
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-24 15:40 -------
Note the backtrace is:
#5211 0x003f58d0 in fold_ternary (code=COND_EXPR, type=0x1e0e5b0, op0=0x1ee9d50, 
op1=0x1e18200, op2=0x1ee2080) at ../../gcc/fold-const.c:9905
#5212 0x003f8368 in fold_build3 (code=COND_EXPR, type=0x1e0e5b0, op0=0x1ee9d50, 
op1=0x1e18200, op2=0x1ee2080) at ../../gcc/fold-const.c:10375
#5213 0x003bb030 in fold_cond_expr_with_comparison (type=0x1e0e5b0, arg0=0x1ee9d50, 
arg1=0x1e18200, arg2=0x1ee2080) at ../../gcc/fold-const.c:4

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[belyshev at depni dot sinp dot msu dot ru]

------- Additional Comments From belyshev at depni dot sinp dot msu dot ru  2005-07-24 15:43 -------
(In reply to comment #5)
> Reduced testcase for the first one:

introduced between "2005-05-17 00:20 UTC" and "2005-05-18 00:20 UTC"

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-24 15:56 -------
The reduced testcase for the second one:
unsigned long CRCTab[256];
void InitCRC(void) {
  int I, J;
  unsigned long C;
  for (I=0; I<256; I++)
  {
    for (C=I,J=0;J<8;J++)
      C=(C & 1) ? (C>>1)^0xEDB88320L : (C>>1);
    CRCTab[I]=C;
  }
}


They do look like the same bug.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[belyshev at depni dot sinp dot msu dot ru]

------- Additional Comments From belyshev at depni dot sinp dot msu dot ru  2005-07-24 16:13 -------
(In reply to comment #8)
> The reduced testcase for the second one:
to make it fail on amd64 one needs to change long -> int. and this testcase
started to fail at the same time as testcase in comment #5 .

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[dorit at il dot ibm dot com]

------- Additional Comments From dorit at il dot ibm dot com  2005-07-27 10:38 -------
This is triggered by tree-ifcvt (which is enabled by -ftree-vectorize)


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dpatel at apple dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-08-01 14:01 -------
*** Bug 23179 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |micis at gmx dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-08-03 00:49 -------
(In reply to comment #10)
> This is triggered by tree-ifcvt (which is enabled by -ftree-vectorize)

But it looks like not a vectorize or tree-ifcvt bug at all but a fold bug.

We get:
0 == 0 ? 0 : 3988292384

in fold but we don't try to fold 0 == 0 first.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-08 20:14 -------
(In reply to comment #12)
> in fold but we don't try to fold 0 == 0 first.

And to confirm this, this is either a DOM or fold bug, fold is not considered recursive, maybe it should 
be in this case.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[janis at gcc dot gnu dot org]

------- Additional Comments From janis at gcc dot gnu dot org  2005-09-09 16:52 -------
The reduced testcase in comment #5 starts failing with this patch from rakdver:

  http://gcc.gnu.org/ml/gcc-cvs/2005-05/msg00814.html

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rakdver at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-13 14:05 -------
*** Bug 23858 has been marked as a duplicate of this bug. ***

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-16 23:34 -------
I have a patch.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |pinskia at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[drab at kepler dot fjfi dot cvut dot cz]

------- Additional Comments From drab at kepler dot fjfi dot cvut dot cz  2005-09-17 14:24 -------
(In reply to comment #16)
> I have a patch.

Excellent! Where is it?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-17 14:53 -------
Here is the patch:
Index: fold-const.c
===============================================================
====
RCS file: /cvs/gcc/gcc/gcc/fold-const.c,v
retrieving revision 1.625
diff -u -p -r1.625 fold-const.c
--- fold-const.c	9 Sep 2005 09:00:33 -0000	1.625
+++ fold-const.c	17 Sep 2005 14:53:00 -0000
@@ -9953,6 +9953,8 @@ fold_ternary (enum tree_code code, tree 
       return NULL_TREE;
 
     case COND_EXPR:
+      /* Fold the condition operand, just in case it needs to be foldded.  */
+      arg0 = fold (arg0);
       /* Pedantic ANSI C says that a conditional expression is never an lvalue,
 	 so all simple results must be passed through pedantic_non_lvalue.  */
       if (TREE_CODE (arg0) == INTEGER_CST)

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-17 14:54 -------
I should note I need to test it still which is why I had not posted it yet.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[rguenth at tat dot physik dot uni-tuebingen dot de]

------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de  2005-09-17 19:31 -------
Please fix the caller who is not folding the condition in the first place instead.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at physics dot uc dot edu]

------- Additional Comments From pinskia at physics dot uc dot edu  2005-09-17 19:38 -------
Subject: Re:  [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

> 
> 
> ------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de  2005-09-17 19:31 -------
> Please fix the caller who is not folding the condition in the first place instead.

we have "a = b == 0 ? 1 : 2;" before in DOM and then we replace b with the value that DOM thinks is correct and then we have "0 == 0 ? 1 : 2;" which is then passed to fold



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-17 23:09 -------
I am not going to fix a DOM bug.

See http://gcc.gnu.org/ml/gcc-patches/2005-09/msg01084.html for more discussion about this bug.

Though I wonder if I would not hit this bug in my tree combiner but I will handle that when I get there.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|pinskia at gcc dot gnu dot  |unassigned at gcc dot gnu
                   |org                         |dot org
             Status|ASSIGNED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |23936


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2005-09-17 23:53 -------
It is hardly a DOM bug.  More an oversight.  Probably easily fixed. 
 
 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |steven at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2005-07-24 15:37:30         |2005-09-17 23:53:02
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[law at redhat dot com]

------- Additional Comments From law at redhat dot com  2005-09-18 00:37 -------
Subject: Re:  [4.1 Regression] ICE with -O3
	-ftree-vectorize on 4.1.x

On Sat, 2005-09-17 at 19:38 +0000, pinskia at physics dot uc dot edu
wrote:
> > ------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de  2005-09-17 19:31 -------
> > Please fix the caller who is not folding the condition in the first place instead.
> 
>  we have "a = b == 0 ? 1 : 2;" before in DOM and then we replace b with
>  the value that DOM thinks is correct and then we have "0 == 0 ? 1 : 2;" which is then
>  passed to fold
Is there some reason fold_stmt (which should have been called after the
replacement by DOM) didn't fold the conditional?

jeff




-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2005-09-18 10:41 -------
Re. comment #24 -- I guess Devang didn't update fold_stmt and similar 
functions for the (still undocumented) modification to GIMPLE to make 
<MODIFY_EXPR <LHS> <COND_EXPR <COND> <RHS1> <RHS2>>> valid. 
 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2005-09-18 15:11 -------
Smaller test case: 
 
static unsigned short int crc_table[256]; 
void AC3_encode_init(void) 
{ 
  unsigned int c, n; 
  for (n = 0; n < 256; n++) 
  { 
    c = n << 8; 
    if (c & 16384) 
      c = c ^ 49155; 
    crc_table[n] = c; 
  } 
} 
 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2005-09-18 15:59 -------
Actually fold_stmt has nothing to do with it.  It is fold (cached_lhs) in 
trhead_across_edge that is the problem here.  Jeff, what do you think about 
this patch? 
 
Index: tree-ssa-dom.c 
=================================================================== 
RCS file: /cvs/gcc/gcc/gcc/tree-ssa-dom.c,v 
retrieving revision 2.127 
diff -u -3 -p -r2.127 tree-ssa-dom.c 
--- tree-ssa-dom.c      2 Aug 2005 00:12:39 -0000       2.127 
+++ tree-ssa-dom.c      18 Sep 2005 15:57:22 -0000 
@@ -701,7 +701,7 @@ thread_across_edge (struct dom_walk_data 
       else 
        { 
          /* Copy the operands.  */ 
-         tree *copy; 
+         tree *copy, prefold_lhs; 
          ssa_op_iter iter; 
          use_operand_p use_p; 
          unsigned int num, i = 0; 
@@ -725,12 +725,33 @@ thread_across_edge (struct dom_walk_data 
 
          /* Try to fold/lookup the new expression.  Inserting the 
             expression into the hash table is unlikely to help 
-            simplify anything later, so just query the hashtable.  */ 
-         cached_lhs = fold (TREE_OPERAND (stmt, 1)); 
-         if (TREE_CODE (cached_lhs) != SSA_NAME 
-             && !is_gimple_min_invariant (cached_lhs)) 
-           cached_lhs = lookup_avail_expr (stmt, false); 
+            simplify anything later, so just query the hashtable. 
 
+            Sadly, we have to handle conditional assignments specially 
+            here, because fold expects all the operands of an expression 
+            to be folded before the expression itself is folded, but we 
+            can't just substitute the folded condition here.  */ 
+         if (TREE_CODE (TREE_OPERAND (stmt, 1)) == COND_EXPR) 
+           { 
+             tree cond = COND_EXPR_COND (TREE_OPERAND (stmt, 1)); 
+             cond = fold (cond); 
+             if (cond == boolean_true_node) 
+               prefold_lhs = COND_EXPR_THEN (TREE_OPERAND (stmt, 1)); 
+             else if (cond == boolean_false_node) 
+               prefold_lhs = COND_EXPR_ELSE (TREE_OPERAND (stmt, 1)); 
+             else 
+               prefold_lhs = NULL; 
+           } 
+         else 
+           prefold_lhs = TREE_OPERAND (stmt, 1); 
+ 
+         if (prefold_lhs) 
+           { 
+             cached_lhs = fold (prefold_lhs); 
+             if (TREE_CODE (cached_lhs) != SSA_NAME 
+                 && !is_gimple_min_invariant (cached_lhs)) 
+               cached_lhs = lookup_avail_expr (stmt, false); 
+           } 
 
          /* Restore the statement's original uses/defs.  */ 
          i = 0; 
 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[law at redhat dot com]

------- Additional Comments From law at redhat dot com  2005-09-20 15:11 -------
Subject: Re:  [4.1 Regression] ICE with -O3
	-ftree-vectorize on 4.1.x

On Sun, 2005-09-18 at 15:59 +0000, steven at gcc dot gnu dot org wrote:
> ------- Additional Comments From steven at gcc dot gnu dot org  2005-09-18 15:59 -------
> Actually fold_stmt has nothing to do with it.  It is fold (cached_lhs) in 
> trhead_across_edge that is the problem here.  Jeff, what do you think about 
> this patch? 
Presumably COND_EXPR on the RHS of a statement is the only special case
that we need to worry about.  I can't immediately think of others.

Seems pretty reasonable, in the case were the COND_EXPR_COND does not
fold, you could safely set pre_fold_lhs to TREE_OPERAND (stmt, 1) which
would allow us to catch cases where the THEN/ELSE clauses of the 
COND_EXPR are equivalent due to substitutions.  But I doubt it's
terribly important.

You might use pre_fold_expr rather than pre_fold_lhs which is a little
confusing since we're looking at the RHS of a statement :-)

jeff





-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049

[Bug tree-optimization/23049] [4.1 Regression] ICE with -O3 -ftree-vectorize on 4.1.x

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-26 13:20 -------
This is also testsuite/gcc.c-torture/execute/builtin-bitops-1.c  failure with "-ftree-vectorize -maltivec" 
on powerpc-darwin, see 
http://gcc.gnu.org/ml/gcc-testresults/2005-09/msg01199.html
http://gcc.gnu.org/ml/gcc-testresults/2005-09/msg01201.html

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23049