Second part.
Martin
>From a5226ccfdc46459afc3474472197aabf51331a63 Mon Sep 17 00:00:00 2001
From: Martin Liska <mli...@suse.cz>
Date: Tue, 2 Jul 2019 09:08:27 +0200
Subject: [PATCH 2/2] Extend DCE to remove unnecessary new/delete-pairs (PR
c++/23383).
gcc/ChangeLog:
2019-07-02 Martin Liska <mli...@suse.cz>
Dominik Infuhr <dominik.infu...@theobroma-systems.com>
PR c++/23383
* common.opt: Add -fallocation-dce
* gimple.c (gimple_call_operator_new_p): New.
(gimple_call_operator_delete_p): Likewise.
* gimple.h (gimple_call_operator_new_p): Likewise.
(gimple_call_operator_delete_p): Likewise.
* tree-core.h (enum function_decl_type): Add OPERATOR_DELETE.
* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Handle
DECL_IS_OPERATOR_DELETE_P.
(mark_all_reaching_defs_necessary_1): Likewise.
(propagate_necessity): Likewise.
(eliminate_unnecessary_stmts): Handle
gimple_call_operator_delete_p.
* tree-streamer-in.c (unpack_ts_function_decl_value_fields):
Add packing of OPERATOR_DELETE.
* tree-streamer-out.c (pack_ts_function_decl_value_fields):
Similarly here.
* tree.h (DECL_IS_OPERATOR_DELETE_P): New.
(DECL_SET_IS_OPERATOR_DELETE): New.
gcc/c/ChangeLog:
2019-07-02 Martin Liska <mli...@suse.cz>
Dominik Infuhr <dominik.infu...@theobroma-systems.com>
PR c++/23383
* c-decl.c (merge_decls): Merge OPERATOR_DELETE flag.
gcc/cp/ChangeLog:
2019-07-02 Martin Liska <mli...@suse.cz>
Dominik Infuhr <dominik.infu...@theobroma-systems.com>
PR c++/23383
* decl.c (cxx_init_decl_processing): Mark delete operators
with DECL_SET_IS_OPERATOR_DELETE.
gcc/testsuite/ChangeLog:
2019-07-02 Martin Liska <mli...@suse.cz
Dominik Infuhr <dominik.infu...@theobroma-systems.com>
PR c++/23383
* g++.dg/cpp1y/new1.C: New test.
libstdc++-v3/ChangeLog:
2019-07-02 Martin Liska <mli...@suse.cz>
Dominik Infuhr <dominik.infu...@theobroma-systems.com>
PR c++/23383
* testsuite/ext/bitmap_allocator/check_delete.cc: Add
-fno-allocation-dce.
* testsuite/ext/bitmap_allocator/check_new.cc: Likewise.
* testsuite/ext/new_allocator/check_delete.cc: Likewise.
* testsuite/ext/new_allocator/check_new.cc: Likewise.
---
gcc/c/c-decl.c | 2 +
gcc/common.opt | 4 ++
gcc/cp/decl.c | 24 ++++---
gcc/gimple.c | 24 +++++++
gcc/gimple.h | 2 +
gcc/testsuite/g++.dg/cpp1y/new1.C | 65 +++++++++++++++++++
gcc/tree-core.h | 1 +
gcc/tree-ssa-dce.c | 34 ++++++++--
gcc/tree-streamer-in.c | 1 +
gcc/tree-streamer-out.c | 1 +
gcc/tree.h | 8 +++
.../ext/bitmap_allocator/check_delete.cc | 2 +
.../ext/bitmap_allocator/check_new.cc | 2 +
.../ext/new_allocator/check_delete.cc | 2 +
.../testsuite/ext/new_allocator/check_new.cc | 2 +
15 files changed, 160 insertions(+), 14 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/new1.C
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index b0a7e34745f..57269751d9c 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -2640,6 +2640,8 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype)
DECL_IS_MALLOC (newdecl) |= DECL_IS_MALLOC (olddecl);
if (DECL_IS_OPERATOR_NEW_P (olddecl))
DECL_SET_IS_OPERATOR_NEW (newdecl, true);
+ if (DECL_IS_OPERATOR_DELETE_P (olddecl))
+ DECL_SET_IS_OPERATOR_DELETE (newdecl, true);
TREE_READONLY (newdecl) |= TREE_READONLY (olddecl);
DECL_PURE_P (newdecl) |= DECL_PURE_P (olddecl);
DECL_IS_NOVOPS (newdecl) |= DECL_IS_NOVOPS (olddecl);
diff --git a/gcc/common.opt b/gcc/common.opt
index a1544d06824..cc9394e5602 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2207,6 +2207,10 @@ Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_
EnumValue
Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
+fallocation-dce
+Common Report Var(flag_allocation_dce) Init(1) Optimization
+Tell DCE to remove unused C++ allocations.
+
flive-range-shrinkage
Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
Relief of register pressure through live range shrinkage.
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 0e9b1b55141..1597090b0ec 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -4362,8 +4362,10 @@ cxx_init_decl_processing (void)
opnew = push_cp_library_fn (VEC_NEW_EXPR, newtype, 0);
DECL_IS_MALLOC (opnew) = 1;
DECL_SET_IS_OPERATOR_NEW (opnew, true);
- push_cp_library_fn (DELETE_EXPR, deltype, ECF_NOTHROW);
- push_cp_library_fn (VEC_DELETE_EXPR, deltype, ECF_NOTHROW);
+ tree opdel = push_cp_library_fn (DELETE_EXPR, deltype, ECF_NOTHROW);
+ DECL_SET_IS_OPERATOR_DELETE (opdel, true);
+ opdel = push_cp_library_fn (VEC_DELETE_EXPR, deltype, ECF_NOTHROW);
+ DECL_SET_IS_OPERATOR_DELETE (opdel, true);
if (flag_sized_deallocation)
{
/* Also push the sized deallocation variants:
@@ -4375,8 +4377,10 @@ cxx_init_decl_processing (void)
deltype = cp_build_type_attribute_variant (void_ftype_ptr_size,
extvisattr);
deltype = build_exception_variant (deltype, empty_except_spec);
- push_cp_library_fn (DELETE_EXPR, deltype, ECF_NOTHROW);
- push_cp_library_fn (VEC_DELETE_EXPR, deltype, ECF_NOTHROW);
+ opdel = push_cp_library_fn (DELETE_EXPR, deltype, ECF_NOTHROW);
+ DECL_SET_IS_OPERATOR_DELETE (opdel, true);
+ opdel = push_cp_library_fn (VEC_DELETE_EXPR, deltype, ECF_NOTHROW);
+ DECL_SET_IS_OPERATOR_DELETE (opdel, true);
}
if (aligned_new_threshold)
@@ -4404,8 +4408,10 @@ cxx_init_decl_processing (void)
align_type_node, NULL_TREE);
deltype = cp_build_type_attribute_variant (deltype, extvisattr);
deltype = build_exception_variant (deltype, empty_except_spec);
- push_cp_library_fn (DELETE_EXPR, deltype, ECF_NOTHROW);
- push_cp_library_fn (VEC_DELETE_EXPR, deltype, ECF_NOTHROW);
+ opdel = push_cp_library_fn (DELETE_EXPR, deltype, ECF_NOTHROW);
+ DECL_SET_IS_OPERATOR_DELETE (opdel, true);
+ opdel = push_cp_library_fn (VEC_DELETE_EXPR, deltype, ECF_NOTHROW);
+ DECL_SET_IS_OPERATOR_DELETE (opdel, true);
if (flag_sized_deallocation)
{
@@ -4415,8 +4421,10 @@ cxx_init_decl_processing (void)
NULL_TREE);
deltype = cp_build_type_attribute_variant (deltype, extvisattr);
deltype = build_exception_variant (deltype, empty_except_spec);
- push_cp_library_fn (DELETE_EXPR, deltype, ECF_NOTHROW);
- push_cp_library_fn (VEC_DELETE_EXPR, deltype, ECF_NOTHROW);
+ opdel = push_cp_library_fn (DELETE_EXPR, deltype, ECF_NOTHROW);
+ DECL_SET_IS_OPERATOR_DELETE (opdel, true);
+ opdel = push_cp_library_fn (VEC_DELETE_EXPR, deltype, ECF_NOTHROW);
+ DECL_SET_IS_OPERATOR_DELETE (opdel, true);
}
}
diff --git a/gcc/gimple.c b/gcc/gimple.c
index 513bde209e2..f0441c12de2 100644
--- a/gcc/gimple.c
+++ b/gcc/gimple.c
@@ -2695,6 +2695,30 @@ gimple_builtin_call_types_compatible_p (const gimple *stmt, tree fndecl)
return true;
}
+/* Return true when STMT is operator new call. */
+
+bool
+gimple_call_operator_new_p (const gcall *stmt)
+{
+ tree fndecl;
+
+ if ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE)
+ return DECL_IS_OPERATOR_NEW_P (fndecl);
+ return false;
+}
+
+/* Return true when STMT is operator delete call. */
+
+bool
+gimple_call_operator_delete_p (const gcall *stmt)
+{
+ tree fndecl;
+
+ if ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE)
+ return DECL_IS_OPERATOR_DELETE_P (fndecl);
+ return false;
+}
+
/* Return true when STMT is builtins call. */
bool
diff --git a/gcc/gimple.h b/gcc/gimple.h
index 47070e7f409..27c09940ad8 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -1549,6 +1549,8 @@ extern alias_set_type gimple_get_alias_set (tree);
extern bool gimple_ior_addresses_taken (bitmap, gimple *);
extern bool gimple_builtin_call_types_compatible_p (const gimple *, tree);
extern combined_fn gimple_call_combined_fn (const gimple *);
+extern bool gimple_call_operator_new_p (const gcall *);
+extern bool gimple_call_operator_delete_p (const gcall *);
extern bool gimple_call_builtin_p (const gimple *);
extern bool gimple_call_builtin_p (const gimple *, enum built_in_class);
extern bool gimple_call_builtin_p (const gimple *, enum built_in_function);
diff --git a/gcc/testsuite/g++.dg/cpp1y/new1.C b/gcc/testsuite/g++.dg/cpp1y/new1.C
new file mode 100644
index 00000000000..a95dd4d1ee3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/new1.C
@@ -0,0 +1,65 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-cddce-details" } */
+
+#include <stdlib.h>
+
+void
+new_without_use() {
+ int *x = new int;
+}
+
+void
+new_array_without_use() {
+ int *x = new int[5];
+}
+
+void
+new_primitive() {
+ int *x = new int;
+ delete x;
+}
+
+void
+new_array() {
+ int *x = new int[10];
+ delete [] x;
+}
+
+void
+new_primitive_store() {
+ int *x = new int;
+ *x = 10;
+ delete x;
+}
+
+void
+new_primitive_load() {
+ int *x = new int;
+ int tmp = *x;
+ delete x;
+}
+
+int
+new_primitive_load_with_use() {
+ int *x = new int;
+ int tmp = *x;
+ delete x;
+ return tmp;
+}
+
+void
+new_array_store() {
+ int *x = new int[10];
+ x[4] = 10;
+ delete [] x;
+}
+
+void
+new_array_load() {
+ int *x = new int[10];
+ int tmp = x[4];
+ delete [] x;
+}
+
+/* { dg-final { scan-tree-dump-times "Deleting : operator delete" 5 "cddce1"} } */
+/* { dg-final { scan-tree-dump-times "Deleting : _\\d+ = operator new" 7 "cddce1"} } */
diff --git a/gcc/tree-core.h b/gcc/tree-core.h
index e0643503e80..cb611956fbd 100644
--- a/gcc/tree-core.h
+++ b/gcc/tree-core.h
@@ -1807,6 +1807,7 @@ enum function_decl_type
{
NONE,
OPERATOR_NEW,
+ OPERATOR_DELETE,
LAMBDA_FUNCTION
/* 0 values left */
diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index c73fbabfe29..532e87e17eb 100644
--- a/gcc/tree-ssa-dce.c
+++ b/gcc/tree-ssa-dce.c
@@ -237,6 +237,12 @@ mark_stmt_if_obviously_necessary (gimple *stmt, bool aggressive)
default:;
}
+
+ if (callee != NULL_TREE
+ && flag_allocation_dce
+ && DECL_IS_OPERATOR_NEW_P (callee))
+ return;
+
/* Most, but not all function calls are required. Function calls that
produce no result and have no side effects (i.e. const pure
functions) are unnecessary. */
@@ -588,6 +594,11 @@ mark_all_reaching_defs_necessary_1 (ao_ref *ref ATTRIBUTE_UNUSED,
default:;
}
+
+ if (callee != NULL_TREE
+ && (DECL_IS_OPERATOR_NEW_P (callee)
+ || DECL_IS_OPERATOR_DELETE_P (callee)))
+ return false;
}
if (! gimple_clobber_p (def_stmt))
@@ -774,7 +785,10 @@ propagate_necessity (bool aggressive)
/* If this is a call to free which is directly fed by an
allocation function do not mark that necessary through
processing the argument. */
- if (gimple_call_builtin_p (stmt, BUILT_IN_FREE))
+ if (gimple_call_builtin_p (stmt, BUILT_IN_FREE)
+ || (is_gimple_call (stmt)
+ && gimple_call_operator_delete_p (as_a <gcall *> (stmt))))
+
{
tree ptr = gimple_call_arg (stmt, 0);
gimple *def_stmt;
@@ -784,10 +798,11 @@ propagate_necessity (bool aggressive)
if (TREE_CODE (ptr) == SSA_NAME
&& is_gimple_call (def_stmt = SSA_NAME_DEF_STMT (ptr))
&& (def_callee = gimple_call_fndecl (def_stmt))
- && DECL_BUILT_IN_CLASS (def_callee) == BUILT_IN_NORMAL
- && (DECL_FUNCTION_CODE (def_callee) == BUILT_IN_ALIGNED_ALLOC
- || DECL_FUNCTION_CODE (def_callee) == BUILT_IN_MALLOC
- || DECL_FUNCTION_CODE (def_callee) == BUILT_IN_CALLOC))
+ && ((DECL_BUILT_IN_CLASS (def_callee) == BUILT_IN_NORMAL
+ && (DECL_FUNCTION_CODE (def_callee) == BUILT_IN_ALIGNED_ALLOC
+ || DECL_FUNCTION_CODE (def_callee) == BUILT_IN_MALLOC
+ || DECL_FUNCTION_CODE (def_callee) == BUILT_IN_CALLOC))
+ || DECL_IS_OPERATOR_NEW_P (def_callee)))
continue;
}
@@ -842,6 +857,11 @@ propagate_necessity (bool aggressive)
|| DECL_FUNCTION_CODE (callee) == BUILT_IN_ASSUME_ALIGNED))
continue;
+ if (callee != NULL_TREE
+ && (DECL_IS_OPERATOR_NEW_P (callee)
+ || DECL_IS_OPERATOR_DELETE_P (callee)))
+ continue;
+
/* Calls implicitly load from memory, their arguments
in addition may explicitly perform memory loads. */
mark_all_reaching_defs_necessary (stmt);
@@ -1262,7 +1282,9 @@ eliminate_unnecessary_stmts (void)
defining statement of its argument is not necessary
(and thus is getting removed). */
if (gimple_plf (stmt, STMT_NECESSARY)
- && gimple_call_builtin_p (stmt, BUILT_IN_FREE))
+ && (gimple_call_builtin_p (stmt, BUILT_IN_FREE)
+ || (is_gimple_call (stmt)
+ && gimple_call_operator_delete_p (as_a <gcall *> (stmt)))))
{
tree ptr = gimple_call_arg (stmt, 0);
if (TREE_CODE (ptr) == SSA_NAME)
diff --git a/gcc/tree-streamer-in.c b/gcc/tree-streamer-in.c
index 7bd21ae7bc5..8b6d4025ddb 100644
--- a/gcc/tree-streamer-in.c
+++ b/gcc/tree-streamer-in.c
@@ -334,6 +334,7 @@ unpack_ts_function_decl_value_fields (struct bitpack_d *bp, tree expr)
DECL_IS_RETURNS_TWICE (expr) = (unsigned) bp_unpack_value (bp, 1);
DECL_IS_MALLOC (expr) = (unsigned) bp_unpack_value (bp, 1);
DECL_SET_IS_OPERATOR_NEW (expr, (unsigned) bp_unpack_value (bp, 1));
+ DECL_SET_IS_OPERATOR_DELETE (expr, (unsigned) bp_unpack_value (bp, 1));
DECL_DECLARED_INLINE_P (expr) = (unsigned) bp_unpack_value (bp, 1);
DECL_STATIC_CHAIN (expr) = (unsigned) bp_unpack_value (bp, 1);
DECL_NO_INLINE_WARNING_P (expr) = (unsigned) bp_unpack_value (bp, 1);
diff --git a/gcc/tree-streamer-out.c b/gcc/tree-streamer-out.c
index 7e93e6c23bb..dbdc5d5e736 100644
--- a/gcc/tree-streamer-out.c
+++ b/gcc/tree-streamer-out.c
@@ -296,6 +296,7 @@ pack_ts_function_decl_value_fields (struct bitpack_d *bp, tree expr)
bp_pack_value (bp, DECL_IS_RETURNS_TWICE (expr), 1);
bp_pack_value (bp, DECL_IS_MALLOC (expr), 1);
bp_pack_value (bp, DECL_IS_OPERATOR_NEW_P (expr), 1);
+ bp_pack_value (bp, DECL_IS_OPERATOR_DELETE_P (expr), 1);
bp_pack_value (bp, DECL_DECLARED_INLINE_P (expr), 1);
bp_pack_value (bp, DECL_STATIC_CHAIN (expr), 1);
bp_pack_value (bp, DECL_NO_INLINE_WARNING_P (expr), 1);
diff --git a/gcc/tree.h b/gcc/tree.h
index 117c2e13335..caa54c2a43d 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -3009,6 +3009,14 @@ set_function_decl_type (tree decl, function_decl_type t, bool set)
#define DECL_SET_IS_OPERATOR_NEW(NODE, VAL) \
set_function_decl_type (FUNCTION_DECL_CHECK (NODE), OPERATOR_NEW, VAL)
+/* Nonzero in a FUNCTION_DECL means this function should be treated as
+ C++ operator delete. */
+#define DECL_IS_OPERATOR_DELETE_P(NODE) \
+ (FUNCTION_DECL_CHECK (NODE)->function_decl.decl_type == OPERATOR_DELETE)
+
+#define DECL_SET_IS_OPERATOR_DELETE(NODE, VAL) \
+ set_function_decl_type (FUNCTION_DECL_CHECK (NODE), OPERATOR_DELETE, VAL)
+
/* Nonzero in a FUNCTION_DECL means this function may return more
than once. */
#define DECL_IS_RETURNS_TWICE(NODE) \
diff --git a/libstdc++-v3/testsuite/ext/bitmap_allocator/check_delete.cc b/libstdc++-v3/testsuite/ext/bitmap_allocator/check_delete.cc
index 1b445643599..1ad1f3c242c 100644
--- a/libstdc++-v3/testsuite/ext/bitmap_allocator/check_delete.cc
+++ b/libstdc++-v3/testsuite/ext/bitmap_allocator/check_delete.cc
@@ -15,6 +15,8 @@
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
+// { dg-options "-fno-allocation-dce" }
+
// 20.4.1.1 allocator members
#include <cstdlib>
diff --git a/libstdc++-v3/testsuite/ext/bitmap_allocator/check_new.cc b/libstdc++-v3/testsuite/ext/bitmap_allocator/check_new.cc
index 0c5f9b6da7c..be16952c10d 100644
--- a/libstdc++-v3/testsuite/ext/bitmap_allocator/check_new.cc
+++ b/libstdc++-v3/testsuite/ext/bitmap_allocator/check_new.cc
@@ -15,6 +15,8 @@
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
+// { dg-options "-fno-allocation-dce" }
+
// 20.4.1.1 allocator members
#include <cstdlib>
diff --git a/libstdc++-v3/testsuite/ext/new_allocator/check_delete.cc b/libstdc++-v3/testsuite/ext/new_allocator/check_delete.cc
index 8778bc9ccaa..dccee1d5293 100644
--- a/libstdc++-v3/testsuite/ext/new_allocator/check_delete.cc
+++ b/libstdc++-v3/testsuite/ext/new_allocator/check_delete.cc
@@ -17,6 +17,8 @@
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
+// { dg-options "-fno-allocation-dce" }
+
// 20.4.1.1 allocator members
#include <cstdlib>
diff --git a/libstdc++-v3/testsuite/ext/new_allocator/check_new.cc b/libstdc++-v3/testsuite/ext/new_allocator/check_new.cc
index fd90d284224..a1d164a6d49 100644
--- a/libstdc++-v3/testsuite/ext/new_allocator/check_new.cc
+++ b/libstdc++-v3/testsuite/ext/new_allocator/check_new.cc
@@ -17,6 +17,8 @@
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
+// { dg-options "-fno-allocation-dce" }
+
// 20.4.1.1 allocator members
#include <cstdlib>
--
2.22.0
