Ok with simply excluding SSA_NAMEs like
@@ -4411,16 +4411,27 @@ gimplify_modify_expr_rhs (tree *expr_p,
/* It's OK to use the target directly if it's being
initialized. */
use_target = true;
- else if (TREE_CODE (*to_p) != SSA_NAME
&& ....)
- /* Don't use the original target if it's already addressable;
- if its address escapes, and the called function uses the
- NRV optimization, a conforming program could see *to_p
- change before the called function returns; see c++/19317.
- When optimizing, the return_slot pass marks more functions
- as safe after we have escape info. */
- use_target = false;
- else
- use_target = true;
as SSA_NAMEs can never become addressable during gimplification.
Ok, since I'm never quite 100% sure I'm following your suggestions...
I'm posting the final patch here. If tests pass, I'll commit.
Thanks again.
* gimple.c (is_gimple_non_addressable): Remove.
* gimple.h: Remove is_gimple_non_addressable.
* gimplify.c (gimplify_modify_expr_rhs): Use is_gimple_reg instead of
is_gimple_non_addressable.
* trans-mem.c (expand_assign_tm): Same.
Index: trans-mem.c
===================================================================
--- trans-mem.c (revision 182908)
+++ trans-mem.c (working copy)
@@ -2184,7 +2184,7 @@ expand_assign_tm (struct tm_region *regi
/* ??? Figure out if there's any possible overlap between the LHS
and the RHS and if not, use MEMCPY. */
- if (load_p && is_gimple_non_addressable (lhs))
+ if (load_p && is_gimple_reg (lhs))
{
tmp = create_tmp_var (TREE_TYPE (lhs), NULL);
lhs_addr = build_fold_addr_expr (tmp);
Index: gimplify.c
===================================================================
--- gimplify.c (revision 182848)
+++ gimplify.c (working copy)
@@ -4411,7 +4411,9 @@ gimplify_modify_expr_rhs (tree *expr_p,
/* It's OK to use the target directly if it's being
initialized. */
use_target = true;
- else if (!is_gimple_non_addressable (*to_p))
+ else if (TREE_CODE (*to_p) != SSA_NAME
+ && (!is_gimple_variable (*to_p)
+ || needs_to_live_in_memory (*to_p)))
/* Don't use the original target if it's already addressable;
if its address escapes, and the called function uses the
NRV optimization, a conforming program could see *to_p
Index: gimple.c
===================================================================
--- gimple.c (revision 182848)
+++ gimple.c (working copy)
@@ -2963,17 +2963,6 @@ is_gimple_reg (tree t)
}
-/* Return true if T is a GIMPLE variable whose address is not needed. */
-
-bool
-is_gimple_non_addressable (tree t)
-{
- if (TREE_CODE (t) == SSA_NAME)
- t = SSA_NAME_VAR (t);
-
- return (is_gimple_variable (t) && ! needs_to_live_in_memory (t));
-}
-
/* Return true if T is a GIMPLE rvalue, i.e. an identifier or a constant. */
bool
Index: gimple.h
===================================================================
--- gimple.h (revision 182848)
+++ gimple.h (working copy)
@@ -1006,9 +1006,6 @@ extern bool is_gimple_mem_rhs (tree);
/* Returns true iff T is a valid if-statement condition. */
extern bool is_gimple_condexpr (tree);
-/* Returns true iff T is a variable that does not need to live in memory. */
-extern bool is_gimple_non_addressable (tree t);
-
/* Returns true iff T is a valid call address expression. */
extern bool is_gimple_call_addr (tree);
