diff options
Diffstat (limited to 'gcc/c-common.c')
| -rw-r--r-- | gcc/c-common.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/gcc/c-common.c b/gcc/c-common.c index fabc181..30c38de 100644 --- a/gcc/c-common.c +++ b/gcc/c-common.c @@ -4185,6 +4185,7 @@ c_expand_expr (exp, target, tmode, modifier) tree rtl_expr; rtx result; bool preserve_result = false; + bool return_target = false; /* Since expand_expr_stmt calls free_temp_slots after every expression statement, we must call push_temp_slots here. @@ -4212,8 +4213,20 @@ c_expand_expr (exp, target, tmode, modifier) if (TREE_CODE (last) == SCOPE_STMT && TREE_CODE (expr) == EXPR_STMT) { - TREE_ADDRESSABLE (expr) = 1; - preserve_result = true; + if (target && TREE_CODE (EXPR_STMT_EXPR (expr)) == VAR_DECL + && DECL_RTL_IF_SET (EXPR_STMT_EXPR (expr)) == target) + /* If the last expression is a variable whose RTL is the + same as our target, just return the target; if it + isn't valid expanding the decl would produce different + RTL, and store_expr would try to do a copy. */ + return_target = true; + else + { + /* Otherwise, note that we want the value from the last + expression. */ + TREE_ADDRESSABLE (expr) = 1; + preserve_result = true; + } } } @@ -4221,7 +4234,9 @@ c_expand_expr (exp, target, tmode, modifier) expand_end_stmt_expr (rtl_expr); result = expand_expr (rtl_expr, target, tmode, modifier); - if (preserve_result && GET_CODE (result) == MEM) + if (return_target) + result = target; + else if (preserve_result && GET_CODE (result) == MEM) { if (GET_MODE (result) != BLKmode) result = copy_to_reg (result); |