[Bug tree-optimization/15654] [3.5 Regression] ICE in calculate_live_on_entry with -O2 -fno-tree-dominator-opts

["rakdver at atrey dot karlin dot mff dot cuni dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From rakdver at atrey dot karlin dot mff dot cuni dot cz  2004-05-27 19:01 -------
Subject: Re:  [3.5 Regression] ICE in calculate_live_on_entry with -O2 -fno-tree-dominator-opts

Hello,

> (In reply to comment #6)
> > The problem actually is in tailcall optimization, where we remove the call
> > that defines iCodeTop_8, but not the assigment iCodeTop_9 = iCodeTop_8
> > that follows it.  I am testing the patch for the problem.
> 
> Thanks to everyone who's helped with this bug!
> 
> How's the testing going Zdenek?

the machine I tested it on crashed, so I am rerunning the tests.  Here
is the patch, if someone wants to try it.

Zdenek

Index: tree-tailcall.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-tailcall.c,v
retrieving revision 2.3
diff -c -3 -p -r2.3 tree-tailcall.c
*** tree-tailcall.c	15 May 2004 09:39:29 -0000	2.3
--- tree-tailcall.c	26 May 2004 23:55:40 -0000
*************** eliminate_tail_call (struct tailcall *t)
*** 646,651 ****
--- 646,652 ----
    stmt_ann_t ann;
    vdef_optype vdefs;
    unsigned i;
+   block_stmt_iterator bsi;
  
    stmt = bsi_stmt (t->call_bsi);
    get_stmt_operands (stmt);
*************** eliminate_tail_call (struct tailcall *t)
*** 665,670 ****
--- 666,686 ----
  
    first = ENTRY_BLOCK_PTR->succ->dest;
  
+   /* Remove the code after call_bsi that will become unreachable.  The
+      possibly unreachable code in other blocks is removed later in
+      cfg cleanup.  */
+   bsi = t->call_bsi;
+   bsi_next (&bsi);
+   while (!bsi_end_p (bsi))
+     {
+       /* Do not remove the return statement, so that redirect_edge_and_branch
+ 	 sees how the block ends.  */
+       if (TREE_CODE (bsi_stmt (bsi)) == RETURN_EXPR)
+ 	break;
+ 
+       bsi_remove (&bsi);
+     }
+ 
    /* Replace the call by a jump to the start of function.  */
    e = redirect_edge_and_branch (t->call_block->succ, first);
    if (!e)
*************** eliminate_tail_call (struct tailcall *t)
*** 682,688 ****
         param = TREE_CHAIN (param),
         args = TREE_CHAIN (args))
      {
-       
        for (phi = phi_nodes (first); phi; phi = TREE_CHAIN (phi))
  	if (param == SSA_NAME_VAR (PHI_RESULT (phi)))
  	  break;
--- 698,703 ----


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15654