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Diffstat (limited to 'gcc/tree-ssa-sccvn.cc')
| -rw-r--r-- | gcc/tree-ssa-sccvn.cc | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc index 00315d1..1c113f8 100644 --- a/gcc/tree-ssa-sccvn.cc +++ b/gcc/tree-ssa-sccvn.cc @@ -5633,6 +5633,28 @@ visit_nary_op (tree lhs, gassign *stmt) } } break; + case BIT_FIELD_REF: + if (TREE_CODE (TREE_OPERAND (rhs1, 0)) == SSA_NAME) + { + tree op0 = TREE_OPERAND (rhs1, 0); + gassign *ass = dyn_cast <gassign *> (SSA_NAME_DEF_STMT (op0)); + if (ass + && !gimple_has_volatile_ops (ass) + && vn_get_stmt_kind (ass) == VN_REFERENCE) + { + tree last_vuse = gimple_vuse (ass); + tree op = build3 (BIT_FIELD_REF, TREE_TYPE (rhs1), + gimple_assign_rhs1 (ass), + TREE_OPERAND (rhs1, 1), TREE_OPERAND (rhs1, 2)); + tree result = vn_reference_lookup (op, gimple_vuse (ass), + default_vn_walk_kind, + NULL, true, &last_vuse); + if (result + && useless_type_conversion_p (type, TREE_TYPE (result))) + return set_ssa_val_to (lhs, result); + } + } + break; case TRUNC_DIV_EXPR: if (TYPE_UNSIGNED (type)) break; |