diff options
Diffstat (limited to 'gcc/cp/optimize.c')
| -rw-r--r-- | gcc/cp/optimize.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/gcc/cp/optimize.c b/gcc/cp/optimize.c index 46f1c85..7a7a27c 100644 --- a/gcc/cp/optimize.c +++ b/gcc/cp/optimize.c @@ -338,6 +338,26 @@ copy_body_r (tp, walk_subtrees, data) TREE_OPERAND (*tp, 1) = TREE_OPERAND (*tp, 3); TREE_OPERAND (*tp, 3) = NULL_TREE; } + else if (TREE_CODE (*tp) == MODIFY_EXPR + && TREE_OPERAND (*tp, 0) == TREE_OPERAND (*tp, 1) + && nonstatic_local_decl_p (TREE_OPERAND (*tp, 0)) + && DECL_CONTEXT (TREE_OPERAND (*tp, 0)) == fn) + { + /* Assignments like a = a; don't generate any rtl code + and don't count as variable modification. Avoid + keeping bogosities like 0 = 0. */ + tree decl = TREE_OPERAND (*tp, 0), value; + splay_tree_node n; + + n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl); + if (n) + { + value = (tree) n->value; + STRIP_TYPE_NOPS (value); + if (TREE_CONSTANT (value) || TREE_READONLY_DECL_P (value)) + *tp = value; + } + } } /* Keep iterating. */ |