2011-09-02 Robert Dewar <dewar@adacore.com>

[pf3gnuchains/gcc-fork.git] / gcc / tree-ssa-sccvn.c

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 5f72f04..4ccc0a2 100644 (file)
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -704,6 +704,7 @@ copy_reference_ops_from_ref (tree ref, VEC(vn_reference_op_s, heap) **result)
        case COMPLEX_CST:
        case VECTOR_CST:
        case REAL_CST:
+       case FIXED_CST:
        case CONSTRUCTOR:
        case SSA_NAME:
          temp.op0 = ref;
@@ -1350,17 +1351,27 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_)
     {
       VEC (vn_reference_op_s, heap) *tem;
       tree lhs = gimple_assign_lhs (def_stmt);
+      bool valueized_anything = false;
       /* Avoid re-allocation overhead.  */
       VEC_truncate (vn_reference_op_s, lhs_ops, 0);
       copy_reference_ops_from_ref (lhs, &lhs_ops);
       tem = lhs_ops;
-      lhs_ops = valueize_refs (lhs_ops);
+      lhs_ops = valueize_refs_1 (lhs_ops, &valueized_anything);
       gcc_assert (lhs_ops == tem);
-      lhs_ref_ok = ao_ref_init_from_vn_reference (&lhs_ref, get_alias_set (lhs),
-                                                 TREE_TYPE (lhs), lhs_ops);
-      if (lhs_ref_ok
-         && !refs_may_alias_p_1 (ref, &lhs_ref, true))
-       return NULL;
+      if (valueized_anything)
+       {
+         lhs_ref_ok = ao_ref_init_from_vn_reference (&lhs_ref,
+                                                     get_alias_set (lhs),
+                                                     TREE_TYPE (lhs), lhs_ops);
+         if (lhs_ref_ok
+             && !refs_may_alias_p_1 (ref, &lhs_ref, true))
+           return NULL;
+       }
+      else
+       {
+         ao_ref_init (&lhs_ref, lhs);
+         lhs_ref_ok = true;
+       }
     }
 
   base = ao_ref_base (ref);
@@ -1468,6 +1479,19 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_)
          j--;
        }
 
+      /* ???  The innermost op should always be a MEM_REF and we already
+         checked that the assignment to the lhs kills vr.  Thus for
+        aggregate copies using char[] types the vn_reference_op_eq
+        may fail when comparing types for compatibility.  But we really
+        don't care here - further lookups with the rewritten operands
+        will simply fail if we messed up types too badly.  */
+      if (j == 0 && i >= 0
+         && VEC_index (vn_reference_op_s, lhs_ops, 0)->opcode == MEM_REF
+         && VEC_index (vn_reference_op_s, lhs_ops, 0)->off != -1
+         && (VEC_index (vn_reference_op_s, lhs_ops, 0)->off
+             == VEC_index (vn_reference_op_s, vr->operands, i)->off))
+       i--, j--;
+
       /* i now points to the first additional op.
         ???  LHS may not be completely contained in VR, one or more
         VIEW_CONVERT_EXPRs could be in its way.  We could at least