On 4/10/20 10:18 AM, Jonathan Wakely wrote:
On Fri, 10 Apr 2020 at 09:08, Martin Liška <mli...@suse.cz> wrote:
Marc pointed out that some targets do not use the leading '_' (or use 2
dashes?) for mangled named?
Double underscore at the start. I think darwin uses that.
Ah yeah, not dashes, but underscores ;)
It's fixed in attached patch that I've been testing right now.
Martin
>From 4043b187ee8e6d7d0c05a6463e38ca54ba4acf75 Mon Sep 17 00:00:00 2001
From: Martin Liska <mli...@suse.cz>
Date: Thu, 9 Apr 2020 15:50:58 +0200
Subject: [PATCH] List valid pairs for new and delete operators.
gcc/ChangeLog:
2020-04-09 Martin Liska <mli...@suse.cz>
PR c++/94314
* cgraphclones.c (set_new_clone_decl_and_node_flags): Drop
DECL_IS_REPLACEABLE_OPERATOR during cloning.
* tree-ssa-dce.c (valid_new_delete_pair_p): New function.
(propagate_necessity): Check operator names.
(perform_tree_ssa_dce): Delete valid_pairs.
gcc/testsuite/ChangeLog:
2020-04-09 Martin Liska <mli...@suse.cz>
PR c++/94314
* g++.dg/pr94314-4.C: New test.
---
gcc/cgraphclones.c | 2 +
gcc/testsuite/g++.dg/pr94314-4.C | 33 +++++++++++
gcc/tree-ssa-dce.c | 99 ++++++++++++++++++++++++++++----
3 files changed, 124 insertions(+), 10 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/pr94314-4.C
diff --git a/gcc/cgraphclones.c b/gcc/cgraphclones.c
index c73b8f810f0..8f541a28b6e 100644
--- a/gcc/cgraphclones.c
+++ b/gcc/cgraphclones.c
@@ -165,6 +165,7 @@ set_new_clone_decl_and_node_flags (cgraph_node *new_node)
DECL_STATIC_DESTRUCTOR (new_node->decl) = 0;
DECL_SET_IS_OPERATOR_NEW (new_node->decl, 0);
DECL_SET_IS_OPERATOR_DELETE (new_node->decl, 0);
+ DECL_IS_REPLACEABLE_OPERATOR (new_node->decl) = 0;
new_node->externally_visible = 0;
new_node->local = 1;
@@ -1030,6 +1031,7 @@ cgraph_node::create_version_clone_with_body
DECL_STATIC_DESTRUCTOR (new_decl) = 0;
DECL_SET_IS_OPERATOR_NEW (new_decl, 0);
DECL_SET_IS_OPERATOR_DELETE (new_decl, 0);
+ DECL_IS_REPLACEABLE_OPERATOR (new_decl) = 0;
/* Create the new version's call-graph node.
and update the edges of the new node. */
diff --git a/gcc/testsuite/g++.dg/pr94314-4.C b/gcc/testsuite/g++.dg/pr94314-4.C
new file mode 100644
index 00000000000..afa2a443dc4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr94314-4.C
@@ -0,0 +1,33 @@
+/* PR c++/94314. */
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-cddce-details -std=c++14" } */
+/* { dg-additional-options "-fdelete-null-pointer-checks" } */
+
+#include <stdio.h>
+
+int count = 0;
+
+__attribute__((malloc, noinline)) void* operator new[](__SIZE_TYPE__ sz) {
+ ++count;
+ return ::operator new(sz);
+}
+
+void operator delete[](void* ptr) noexcept {
+ --count;
+ ::operator delete(ptr);
+}
+
+void operator delete[](void* ptr, __SIZE_TYPE__ sz) noexcept {
+ --count;
+ ::operator delete(ptr, sz);
+}
+
+int main() {
+ delete[] new int[1];
+ if (count != 0)
+ __builtin_abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump-not "Deleting : operator delete" "cddce1"} } */
diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index fd5f24c746c..f66069e410d 100644
--- a/gcc/tree-ssa-dce.c
+++ b/gcc/tree-ssa-dce.c
@@ -646,6 +646,76 @@ degenerate_phi_p (gimple *phi)
return true;
}
+/* Valid pairs of new and delete operators for DCE. */
+static hash_set<nofree_string_hash> *valid_pairs = NULL;
+
+/* Return that NEW_CALL and DELETE_CALL are a valid pair of new
+ and delete operators. */
+
+static bool
+valid_new_delete_pair_p (gimple *new_call, gimple *delete_call)
+{
+ const char *new_name
+ = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (gimple_call_fndecl (new_call)));
+ const char *delete_name
+ = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (gimple_call_fndecl (delete_call)));
+
+ if (new_name[0] == '_' and new_name[1] == '_')
+ ++new_name;
+ if (delete_name[0] == '_' and delete_name[1] == '_')
+ ++delete_name;
+
+ char *needle = concat (new_name, ":", delete_name, NULL);
+
+ if (valid_pairs == NULL)
+ {
+ valid_pairs = new hash_set<nofree_string_hash> ();
+ /* Invalid pairs:
+ non-[] and []
+ aligned and non-aligned
+ */
+
+ const char *pairs[] = {
+ /* non-[] operators. */
+ "_Znwm:_ZdlPv" ,
+ "_Znwm:_ZdlPvm" ,
+ "_Znwm:_ZdlPvRKSt9nothrow_t" ,
+ "_ZnwmRKSt9nothrow_t:_ZdlPv" ,
+ "_ZnwmRKSt9nothrow_t:_ZdlPvm" ,
+ "_ZnwmRKSt9nothrow_t:_ZdlPvRKSt9nothrow_t" ,
+ /* non-[] operators with alignment. */
+ "_ZnwmSt11align_val_t:_ZdlPvmSt11align_val_t" ,
+ "_ZnwmSt11align_val_t:_ZdlPvSt11align_val_t" ,
+ "_ZnwmSt11align_val_t:_ZdlPvSt11align_val_tRKSt9nothrow_t" ,
+ "_ZnwmSt11align_val_tRKSt9nothrow_t:_ZdlPvmSt11align_val_t" ,
+ "_ZnwmSt11align_val_tRKSt9nothrow_t:_ZdlPvSt11align_val_t" ,
+ "_ZnwmSt11align_val_tRKSt9nothrow_t:_ZdlPvSt11align_val_tRKSt9nothrow_t" ,
+ /* [] operators. */
+ "_Znam:_ZdaPv" ,
+ "_Znam:_ZdaPvm" ,
+ "_Znam:_ZdaPvRKSt9nothrow_t" ,
+ "_ZnamRKSt9nothrow_t:_ZdaPv" ,
+ "_ZnamRKSt9nothrow_t:_ZdaPvm" ,
+ "_ZnamRKSt9nothrow_t:_ZdaPvRKSt9nothrow_t" ,
+ /* [] operators with alignment. */
+ "_ZnamSt11align_val_t:_ZdaPvmSt11align_val_t" ,
+ "_ZnamSt11align_val_t:_ZdaPvSt11align_val_t" ,
+ "_ZnamSt11align_val_t:_ZdaPvSt11align_val_tRKSt9nothrow_t" ,
+ "_ZnamSt11align_val_tRKSt9nothrow_t:_ZdaPvmSt11align_val_t",
+ "_ZnamSt11align_val_tRKSt9nothrow_t:_ZdaPvSt11align_val_t",
+ "_ZnamSt11align_val_tRKSt9nothrow_t:_ZdaPvSt11align_val_tRKSt9nothrow_t",
+ NULL
+ };
+
+ for (unsigned i = 0; pairs[i] != NULL; i++)
+ valid_pairs->add (pairs[i]);
+ }
+
+ bool r = valid_pairs->contains (needle);
+ free (needle);
+ return r;
+}
+
/* Propagate necessity using the operands of necessary statements.
Process the uses on each statement in the worklist, and add all
feeding statements which contribute to the calculation of this
@@ -824,16 +894,23 @@ propagate_necessity (bool aggressive)
|| DECL_FUNCTION_CODE (def_callee) == BUILT_IN_CALLOC))
|| DECL_IS_REPLACEABLE_OPERATOR_NEW_P (def_callee)))
{
- /* Delete operators can have alignment and (or) size as next
- arguments. When being a SSA_NAME, they must be marked
- as necessary. */
- if (is_delete_operator && gimple_call_num_args (stmt) >= 2)
- for (unsigned i = 1; i < gimple_call_num_args (stmt); i++)
- {
- tree arg = gimple_call_arg (stmt, i);
- if (TREE_CODE (arg) == SSA_NAME)
- mark_operand_necessary (arg);
- }
+ if (is_delete_operator)
+ {
+ if (!valid_new_delete_pair_p (def_stmt, stmt))
+ mark_operand_necessary (gimple_call_arg (stmt, 0));
+
+ /* Delete operators can have alignment and (or) size
+ as next arguments. When being a SSA_NAME, they
+ must be marked as necessary. */
+ if (gimple_call_num_args (stmt) >= 2)
+ for (unsigned i = 1; i < gimple_call_num_args (stmt);
+ i++)
+ {
+ tree arg = gimple_call_arg (stmt, i);
+ if (TREE_CODE (arg) == SSA_NAME)
+ mark_operand_necessary (arg);
+ }
+ }
continue;
}
@@ -1662,6 +1739,8 @@ perform_tree_ssa_dce (bool aggressive)
visited = BITMAP_ALLOC (NULL);
propagate_necessity (aggressive);
BITMAP_FREE (visited);
+ delete valid_pairs;
+ valid_pairs = NULL;
something_changed |= eliminate_unnecessary_stmts ();
something_changed |= cfg_altered;
--
2.26.0
