[PATCH] Fix PR77979

[Richard Biener]

The following fixes PR77979, yet another case where the jump-threading
code in VRP makes things difficult.

Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.

Richard.

2016-10-14  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/77979
        * tree-vrp.c (compare_name_with_value): Handle released SSA names
        in the equivalency sets.
        (compare_names): Likewise.

        * gcc.dg/torture/pr77979.c: New testcase.

Index: gcc/tree-vrp.c
===================================================================
*** gcc/tree-vrp.c      (revision 241148)
--- gcc/tree-vrp.c      (working copy)
*************** compare_name_with_value (enum tree_code
*** 7188,7196 ****
  
    EXECUTE_IF_SET_IN_BITMAP (e, 0, i, bi)
      {
        if (! use_equiv_p
!         && ! SSA_NAME_IS_DEFAULT_DEF (ssa_name (i))
!         && prop_simulate_again_p (SSA_NAME_DEF_STMT (ssa_name (i))))
        continue;
  
        equiv_vr = get_vr_for_comparison (i);
--- 7188,7200 ----
  
    EXECUTE_IF_SET_IN_BITMAP (e, 0, i, bi)
      {
+       tree name = ssa_name (i);
+       if (! name)
+       continue;
+ 
        if (! use_equiv_p
!         && ! SSA_NAME_IS_DEFAULT_DEF (name)
!         && prop_simulate_again_p (SSA_NAME_DEF_STMT (name)))
        continue;
  
        equiv_vr = get_vr_for_comparison (i);
*************** compare_names (enum tree_code comp, tree
*** 7289,7299 ****
--- 7293,7309 ----
       of the loop just to check N1 and N2 ranges.  */
    EXECUTE_IF_SET_IN_BITMAP (e1, 0, i1, bi1)
      {
+       if (! ssa_name (i1))
+       continue;
+ 
        value_range vr1 = get_vr_for_comparison (i1);
  
        t = retval = NULL_TREE;
        EXECUTE_IF_SET_IN_BITMAP (e2, 0, i2, bi2)
        {
+         if (! ssa_name (i2))
+           continue;
+ 
          bool sop = false;
  
          value_range vr2 = get_vr_for_comparison (i2);
Index: gcc/testsuite/gcc.dg/torture/pr77979.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr77979.c      (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr77979.c      (working copy)
***************
*** 0 ****
--- 1,12 ----
+ /* { dg-do compile } */
+ 
+ int a, b, c, d, e, f;
+ 
+ void fn1 ()
+ { 
+   int g = b;
+   a = -~(d || a) << 4 || e;
+   b = c || g ^ a;
+   if (f < g)
+     d = e;
+ }