re PR tree-optimization/66949 (ICE at -O2 and -O3 on x86_64-linux-gnu in…

re PR tree-optimization/66949 (ICE at -O2 and -O3 on x86_64-linux-gnu in tree_ssa_phiopt_worker, at tree-ssa-phiopt.c:335)

	PR tree-optimization/66949
	* tree-ssa-phiopt.c (tree_ssa_phiopt_worker): Don't call 
	single_non_singleton_phi_for_edges to get the PHI from
	factor_out_conditional_conversion.  Use NULL_TREE instead of NULL.
	(factor_out_conditional_conversion): Adjust declaration.  Make it
	return the newly-created PHI.

	* gcc.dg/torture/pr66949-1.c: New test.
	* gcc.dg/torture/pr66949-2.c: New test.

From-SVN: r231457

gcc/ChangeLog

+2015-12-09  Marek Polacek  <polacek@redhat.com>
+
+	PR tree-optimization/66949
+	* tree-ssa-phiopt.c (tree_ssa_phiopt_worker): Don't call 
+	single_non_singleton_phi_for_edges to get the PHI from
+	factor_out_conditional_conversion.  Use NULL_TREE instead of NULL.
+	(factor_out_conditional_conversion): Adjust declaration.  Make it
+	return the newly-created PHI.
+
 2015-12-09  James Greenhalgh  <james.greenhalgh@arm.com>
 
 	* config/aarch64/aarch64-protos.h

gcc/testsuite/ChangeLog

+2015-12-09  Marek Polacek  <polacek@redhat.com>
+
+	PR tree-optimization/66949
+	* gcc.dg/torture/pr66949-1.c: New test.
+	* gcc.dg/torture/pr66949-2.c: New test.
+
 2015-12-09  James Greenhalgh  <james.greenhalgh@arm.com>
 
 	PR rtl-optimization/67609

gcc/testsuite/gcc.dg/torture/pr66949-1.c

+/* PR tree-optimization/66949 */
+/* { dg-do compile } */
+
+int a, *b = &a, c;
+
+unsigned short
+fn1 (unsigned short p1, unsigned int p2)
+{
+  return p2 > 1 || p1 >> p2 ? p1 : p1 << p2;
+}
+
+void
+fn2 ()
+{
+  int *d = &a;
+  for (a = 0; a < -1; a = 1)
+    ;
+  if (a < 0)
+    c = 0;
+  *b = fn1 (*d || c, *d);
+}
+
+int
+main ()
+{
+  fn2 ();
+  return 0;
+}

gcc/testsuite/gcc.dg/torture/pr66949-2.c

+/* PR tree-optimization/66949 */
+/* { dg-do compile } */
+
+char a;
+int b, c, d;
+extern int fn2 (void);
+
+short
+fn1 (short p1, short p2)
+{
+  return p2 == 0 ? p1 : p1 / p2;
+}
+
+int
+main (void)
+{
+  char e = 1;
+  int f = 7;
+  c = a >> f;
+  b = fn1 (c, 0 < d <= e && fn2 ());
+
+  return 0;
+}

gcc/tree-ssa-phiopt.c

@@ -49,7 +49,7 @@ along with GCC; see the file COPYING3.  If not see
 static unsigned int tree_ssa_phiopt_worker (bool, bool);
 static bool conditional_replacement (basic_block, basic_block,
 				     edge, edge, gphi *, tree, tree);
-static bool factor_out_conditional_conversion (edge, edge, gphi *, tree, tree);
+static gphi *factor_out_conditional_conversion (edge, edge, gphi *, tree, tree);
 static int value_replacement (basic_block, basic_block,
 			      edge, edge, gimple *, tree, tree);
 static bool minmax_replacement (basic_block, basic_block,
@@ -310,19 +310,19 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads)
 
 	  /* Something is wrong if we cannot find the arguments in the PHI
 	     node.  */
-	  gcc_assert (arg0 != NULL && arg1 != NULL);
+	  gcc_assert (arg0 != NULL_TREE && arg1 != NULL_TREE);
 
-	  if (factor_out_conditional_conversion (e1, e2, phi, arg0, arg1))
+	  gphi *newphi = factor_out_conditional_conversion (e1, e2, phi,
+							    arg0, arg1);
+	  if (newphi != NULL)
 	    {
+	      phi = newphi;
 	      /* factor_out_conditional_conversion may create a new PHI in
 		 BB2 and eliminate an existing PHI in BB2.  Recompute values
 		 that may be affected by that change.  */
-	      phis = phi_nodes (bb2);
-	      phi = single_non_singleton_phi_for_edges (phis, e1, e2);
-	      gcc_assert (phi);
 	      arg0 = gimple_phi_arg_def (phi, e1->dest_idx);
 	      arg1 = gimple_phi_arg_def (phi, e2->dest_idx);
-	      gcc_assert (arg0 != NULL && arg1 != NULL);
+	      gcc_assert (arg0 != NULL_TREE && arg1 != NULL_TREE);
 	    }
 
 	  /* Do the replacement of conditional if it can be done.  */
@@ -402,9 +402,9 @@ replace_phi_edge_with_variable (basic_block cond_block,
 
 /* PR66726: Factor conversion out of COND_EXPR.  If the arguments of the PHI
    stmt are CONVERT_STMT, factor out the conversion and perform the conversion
-   to the result of PHI stmt.  */
+   to the result of PHI stmt.  Return the newly-created PHI, if any.  */
 
-static bool
+static gphi *
 factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
 				   tree arg0, tree arg1)
 {
@@ -421,7 +421,7 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
      statement have the same unary operation, we can handle more
      than two arguments too.  */
   if (gimple_phi_num_args (phi) != 2)
-    return false;
+    return NULL;
 
   /* First canonicalize to simplify tests.  */
   if (TREE_CODE (arg0) != SSA_NAME)
@@ -433,14 +433,14 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
   if (TREE_CODE (arg0) != SSA_NAME
       || (TREE_CODE (arg1) != SSA_NAME
 	  && TREE_CODE (arg1) != INTEGER_CST))
-    return false;
+    return NULL;
 
   /* Check if arg0 is an SSA_NAME and the stmt which defines arg0 is
      a conversion.  */
   arg0_def_stmt = SSA_NAME_DEF_STMT (arg0);
   if (!is_gimple_assign (arg0_def_stmt)
       || !gimple_assign_cast_p (arg0_def_stmt))
-    return false;
+    return NULL;
 
   /* Use the RHS as new_arg0.  */
   convert_code = gimple_assign_rhs_code (arg0_def_stmt);
@@ -455,7 +455,7 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
       arg1_def_stmt = SSA_NAME_DEF_STMT (arg1);
       if (!is_gimple_assign (arg1_def_stmt)
 	  || gimple_assign_rhs_code (arg1_def_stmt) != convert_code)
-	return false;
+	return NULL;
 
       /* Use the RHS as new_arg1.  */
       new_arg1 = gimple_assign_rhs1 (arg1_def_stmt);
@@ -471,21 +471,21 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
 	  if (gimple_assign_cast_p (arg0_def_stmt))
 	    new_arg1 = fold_convert (TREE_TYPE (new_arg0), arg1);
 	  else
-	    return false;
+	    return NULL;
 	}
       else
-	return false;
+	return NULL;
     }
 
   /*  If arg0/arg1 have > 1 use, then this transformation actually increases
       the number of expressions evaluated at runtime.  */
   if (!has_single_use (arg0)
       || (arg1_def_stmt && !has_single_use (arg1)))
-    return false;
+    return NULL;
 
   /* If types of new_arg0 and new_arg1 are different bailout.  */
   if (!types_compatible_p (TREE_TYPE (new_arg0), TREE_TYPE (new_arg1)))
-    return false;
+    return NULL;
 
   /* Create a new PHI stmt.  */
   result = PHI_RESULT (phi);
@@ -528,7 +528,7 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
   /* Remove the original PHI stmt.  */
   gsi = gsi_for_stmt (phi);
   gsi_remove (&gsi, true);
-  return true;
+  return newphi;
 }
 
 /*  The function conditional_replacement does the main work of doing the