On 8/7/19 4:12 PM, Richard Biener wrote:
> On Wed, Aug 7, 2019 at 2:04 PM Martin Liška <mli...@suse.cz> wrote:
>>
>> On 8/7/19 12:51 PM, Jakub Jelinek wrote:
>>> On Wed, Aug 07, 2019 at 12:44:28PM +0200, Martin Liška wrote:
>>>> On 8/7/19 11:51 AM, Richard Biener wrote:
>>>>> I think the simplest way to achieve this is to not copy, aka clear,
>>>>> DECL_IS_OPERATOR_* when cloning and removing arguments
>>>>> (cloning for a constant align argument should be OK for example, as is
>>>>> for a constant address). Or simply always when cloning.
>>>>
>>>> Ok, then I'm suggesting following tested patch.
>>>>
>>>> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>>>
>>> What about LAMBDA_FUNCTION, doesn't cloning which changes arguments in any
>>> way invalidate that too, i.e. shouldn't it be just
>>> FUNCTION_DECL_DECL_TYPE (new_node->decl) = NONE;
>>
>> Well, how are lambdas involved in the new/delete DCE here? Lambdas with
>> removed
>> arguments should not interfere here.
>
> But for coverage where we do
>
> gcov_write_unsigned (DECL_ARTIFICIAL (current_function_decl)
> && !DECL_FUNCTION_VERSIONED (current_function_decl)
> && !DECL_LAMBDA_FUNCTION_P (current_function_decl));
>
> all clones should be considered artificial?
Well, from coverage perspective most of them are fine.
>
> Anyway, your patch is OK, we can think about lambdas separately. Can you
> simplify the DCE code after the patch?
I installed the patch and I'm sending the follow up cleanup.
Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
Ready to be installed?
Thanks,
Martin
>
> Thanks,
> Richard.
>
>>> instead? On the other side, if the cloning doesn't change arguments in any
>>> way, do we still want to clear those flags?
>>
>> Well, I would consider it safer to drop it always.
>>
>> Martin
>>
>>>
>>> Jakub
>>>
>>
>From 9da5bd0a2c81a20807caf9cc6915971067b021c3 Mon Sep 17 00:00:00 2001
From: Martin Liska <mli...@suse.cz>
Date: Thu, 8 Aug 2019 09:58:34 +0200
Subject: [PATCH] Clean up dead condition for operators in DCE.
gcc/ChangeLog:
2019-08-08 Martin Liska <mli...@suse.cz>
* tree-ssa-dce.c (propagate_necessity): We can't reach now
operators with no arguments.
(eliminate_unnecessary_stmts): Likewise here.
---
gcc/tree-ssa-dce.c | 22 ++++++----------------
1 file changed, 6 insertions(+), 16 deletions(-)
diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index afb7bd9dedc..80d5f5c30f7 100644
--- a/gcc/tree-ssa-dce.c
+++ b/gcc/tree-ssa-dce.c
@@ -810,11 +810,6 @@ propagate_necessity (bool aggressive)
if (is_delete_operator
|| gimple_call_builtin_p (stmt, BUILT_IN_FREE))
{
- /* It can happen that a user delete operator has the pointer
- argument optimized out already. */
- if (gimple_call_num_args (stmt) == 0)
- continue;
-
tree ptr = gimple_call_arg (stmt, 0);
gimple *def_stmt;
tree def_callee;
@@ -1328,18 +1323,13 @@ eliminate_unnecessary_stmts (void)
|| (is_gimple_call (stmt)
&& gimple_call_operator_delete_p (as_a <gcall *> (stmt)))))
{
- /* It can happen that a user delete operator has the pointer
- argument optimized out already. */
- if (gimple_call_num_args (stmt) > 0)
+ tree ptr = gimple_call_arg (stmt, 0);
+ if (TREE_CODE (ptr) == SSA_NAME)
{
- tree ptr = gimple_call_arg (stmt, 0);
- if (TREE_CODE (ptr) == SSA_NAME)
- {
- gimple *def_stmt = SSA_NAME_DEF_STMT (ptr);
- if (!gimple_nop_p (def_stmt)
- && !gimple_plf (def_stmt, STMT_NECESSARY))
- gimple_set_plf (stmt, STMT_NECESSARY, false);
- }
+ gimple *def_stmt = SSA_NAME_DEF_STMT (ptr);
+ if (!gimple_nop_p (def_stmt)
+ && !gimple_plf (def_stmt, STMT_NECESSARY))
+ gimple_set_plf (stmt, STMT_NECESSARY, false);
}
}
--
2.22.0
