Merged revisions 196607-196608,196611-196614,196625,196629-196634,196636,196639,196645-196647,196649-196650,196654-196659,196666,196669,196671-196675,196682-196683,196694-196695,196697-196698,196700-196701,196704-196706,196709,196721-196748,196750-196751,196753,196755-196758,196762,196764-196765,196767-196771,196773-196779,196781-196784,196788-196792,196795-196797,196799-196800,196804-196807,196810-196814,196821,196823-196825,196828-196829,196831-196832,196834,196841-196842,196847-196853,196855-196856,196858,196860-196861,196864-196866,196868,196870-196872,196874,196876,196878-196879,196882,196884-196890,196896-196897,196899-196902,196954,196956-196961,196964-196965,196970,196977-196978,196981-196983,196989,197002-197005,197007,197011-197012,197016-197019,197021,197023-197025,197029-197034,197036-197042 via svnmerge from cxx-conversion

svn+ssh://gcc.gnu.org/svn/gcc/trunk



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/cxx-conversion@197098 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 34 insertions, 21 deletions

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 2609f668942..07bfdcccb81 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -2715,18 +2715,13 @@ static tree valueize_expr (tree expr);
 static bool
 visit_copy (tree lhs, tree rhs)
 {
-  /* Follow chains of copies to their destination.  */
-  while (TREE_CODE (rhs) == SSA_NAME
-	 && SSA_VAL (rhs) != rhs)
-    rhs = SSA_VAL (rhs);
-
   /* The copy may have a more interesting constant filled expression
      (we don't, since we know our RHS is just an SSA name).  */
-  if (TREE_CODE (rhs) == SSA_NAME)
-    {
-      VN_INFO (lhs)->has_constants = VN_INFO (rhs)->has_constants;
-      VN_INFO (lhs)->expr = VN_INFO (rhs)->expr;
-    }
+  VN_INFO (lhs)->has_constants = VN_INFO (rhs)->has_constants;
+  VN_INFO (lhs)->expr = VN_INFO (rhs)->expr;
+
+  /* And finally valueize.  */
+  rhs = SSA_VAL (rhs);
 
   return set_ssa_val_to (lhs, rhs);
 }
@@ -3125,25 +3120,38 @@ expr_has_constants (tree expr)
 static bool
 stmt_has_constants (gimple stmt)
 {
+  tree tem;
+
   if (gimple_code (stmt) != GIMPLE_ASSIGN)
     return false;
 
   switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)))
     {
-    case GIMPLE_UNARY_RHS:
-      return is_gimple_min_invariant (gimple_assign_rhs1 (stmt));
+    case GIMPLE_TERNARY_RHS:
+      tem = gimple_assign_rhs3 (stmt);
+      if (TREE_CODE (tem) == SSA_NAME)
+	tem = SSA_VAL (tem);
+      if (is_gimple_min_invariant (tem))
+	return true;
+      /* Fallthru.  */
 
     case GIMPLE_BINARY_RHS:
-      return (is_gimple_min_invariant (gimple_assign_rhs1 (stmt))
-	      || is_gimple_min_invariant (gimple_assign_rhs2 (stmt)));
-    case GIMPLE_TERNARY_RHS:
-      return (is_gimple_min_invariant (gimple_assign_rhs1 (stmt))
-	      || is_gimple_min_invariant (gimple_assign_rhs2 (stmt))
-	      || is_gimple_min_invariant (gimple_assign_rhs3 (stmt)));
+      tem = gimple_assign_rhs2 (stmt);
+      if (TREE_CODE (tem) == SSA_NAME)
+	tem = SSA_VAL (tem);
+      if (is_gimple_min_invariant (tem))
+	return true;
+      /* Fallthru.  */
+
     case GIMPLE_SINGLE_RHS:
       /* Constants inside reference ops are rarely interesting, but
 	 it can take a lot of looking to find them.  */
-      return is_gimple_min_invariant (gimple_assign_rhs1 (stmt));
+    case GIMPLE_UNARY_RHS:
+      tem = gimple_assign_rhs1 (stmt);
+      if (TREE_CODE (tem) == SSA_NAME)
+	tem = SSA_VAL (tem);
+      return is_gimple_min_invariant (tem);
+
     default:
       gcc_unreachable ();
     }
@@ -3561,8 +3569,13 @@ visit_use (tree use)
 		     We can value number 2 calls to the same function with the
 		     same vuse and the same operands which are not subsequent
 		     the same, because there is no code in the program that can
-		     compare the 2 values.  */
-		  || gimple_vdef (stmt)))
+		     compare the 2 values...  */
+		  || (gimple_vdef (stmt)
+		      /* ... unless the call returns a pointer which does
+		         not alias with anything else.  In which case the
+			 information that the values are distinct are encoded
+			 in the IL.  */
+		      && !(gimple_call_return_flags (stmt) & ERF_NOALIAS))))
 	    changed = visit_reference_op_call (lhs, stmt);
 	  else
 	    changed = defs_to_varying (stmt);