From 04e9b412e49a3966f84edd3afda66ebdb729efdc Mon Sep 17 00:00:00 2001 From: yongxiangng Date: Thu, 27 Jul 2023 08:01:42 +0800 Subject: [PATCH 1/1] [PATCH] c++: devirtualization of array destruction [PR110057] PR c++/110057 PR ipa/83054 gcc/cp/ChangeLog: * init.cc (build_vec_delete_1): Devirtualize array destruction. gcc/testsuite/ChangeLog: * g++.dg/warn/pr83054.C: Remove devirtualization warning. * g++.dg/tree-ssa/devirt-array-destructor-1.C: New test. * g++.dg/tree-ssa/devirt-array-destructor-2.C: New test. * g++.dg/warn/pr83054-2.C: New test. Signed-off-by: Ng Yong Xiang --- gcc/cp/init.cc | 8 ++-- .../tree-ssa/devirt-array-destructor-1.C | 28 ++++++++++++ .../tree-ssa/devirt-array-destructor-2.C | 29 ++++++++++++ gcc/testsuite/g++.dg/warn/pr83054-2.C | 44 +++++++++++++++++++ gcc/testsuite/g++.dg/warn/pr83054.C | 2 +- 5 files changed, 106 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-1.C create mode 100644 gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-2.C create mode 100644 gcc/testsuite/g++.dg/warn/pr83054-2.C diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc index 6ccda365b04..69ab51d0a4b 100644 --- a/gcc/cp/init.cc +++ b/gcc/cp/init.cc @@ -4112,8 +4112,8 @@ build_vec_delete_1 (location_t loc, tree base, tree maxindex, tree type, if (type_build_dtor_call (type)) { tmp = build_delete (loc, ptype, base, sfk_complete_destructor, - LOOKUP_NORMAL|LOOKUP_DESTRUCTOR, 1, - complain); + LOOKUP_NORMAL|LOOKUP_DESTRUCTOR|LOOKUP_NONVIRTUAL, + 1, complain); if (tmp == error_mark_node) return error_mark_node; } @@ -4143,8 +4143,8 @@ build_vec_delete_1 (location_t loc, tree base, tree maxindex, tree type, return error_mark_node; body = build_compound_expr (loc, body, tmp); tmp = build_delete (loc, ptype, tbase, sfk_complete_destructor, - LOOKUP_NORMAL|LOOKUP_DESTRUCTOR, 1, - complain); + LOOKUP_NORMAL|LOOKUP_DESTRUCTOR|LOOKUP_NONVIRTUAL, + 1, complain); if (tmp == error_mark_node) return error_mark_node; body = build_compound_expr (loc, body, tmp); diff --git a/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-1.C b/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-1.C new file mode 100644 index 00000000000..ce8dc2a57cd --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-1.C @@ -0,0 +1,28 @@ +// PR c++/110057 +/* { dg-do-compile } */ +/* Virtual calls should be devirtualized because we know dynamic type of object in array at compile time */ +/* { dg-options "-O3 -fdump-tree-optimized -fno-inline" } */ + +class A +{ +public: + virtual ~A() + { + } +}; + +class B : public A +{ +public: + virtual ~B() + { + } +}; + +int main() +{ + B b[10]; + return 0; +} + +/* { dg-final { scan-tree-dump-times "OBJ_TYPE_REF" 0 "optimized"} } */ diff --git a/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-2.C b/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-2.C new file mode 100644 index 00000000000..6b44dc1a4ee --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-2.C @@ -0,0 +1,29 @@ +// PR c++/110057 +/* { dg-do-compile } */ +/* Virtual calls should be devirtualized because we know dynamic type of object in array at compile time */ +/* { dg-options "-O3 -fdump-tree-optimized -fno-inline" } */ + +class A +{ +public: + virtual ~A() + { + } +}; + +class B : public A +{ +public: + virtual ~B() + { + } +}; + +int main() +{ + B* ptr = new B[10]; + delete[] ptr; + return 0; +} + +/* { dg-final { scan-tree-dump-times "OBJ_TYPE_REF" 0 "optimized"} } */ diff --git a/gcc/testsuite/g++.dg/warn/pr83054-2.C b/gcc/testsuite/g++.dg/warn/pr83054-2.C new file mode 100644 index 00000000000..6d8216d229f --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/pr83054-2.C @@ -0,0 +1,44 @@ +// PR ipa/83054 +// { dg-options "-O3 -Wsuggest-final-types" } +// { dg-do compile } + +// A throwing dtor in C++98 mode changes the warning. +#if __cplusplus < 201100L +#define NOTHROW throw() +#else +#define NOTHROW noexcept +#endif + +extern "C" int printf (const char *, ...); +struct foo // { dg-warning "final would enable devirtualization of 1 call" } +{ + static int count; + void print (int i, int j) { printf ("foo[%d][%d] = %d\n", i, j, x); } + int x; + foo () { + x = count++; + printf("this %d = %x\n", x, (void *)this); + } + virtual ~foo () NOTHROW { + printf("this %d = %x\n", x, (void *)this); + --count; + } +}; +int foo::count; + + +int main () +{ + foo *arr[9]; + for (int i = 0; i < 9; ++i) + arr[i] = new foo(); + if (foo::count != 9) + return 1; + for (int i = 0; i < 9; ++i) + arr[i]->print(i / 3, i % 3); + for (int i = 0; i < 9; ++i) + delete arr[i]; + if (foo::count != 0) + return 1; + return 0; +} diff --git a/gcc/testsuite/g++.dg/warn/pr83054.C b/gcc/testsuite/g++.dg/warn/pr83054.C index 5285f94acee..5a4a6abe248 100644 --- a/gcc/testsuite/g++.dg/warn/pr83054.C +++ b/gcc/testsuite/g++.dg/warn/pr83054.C @@ -10,7 +10,7 @@ #endif extern "C" int printf (const char *, ...); -struct foo // { dg-warning "final would enable devirtualization of 5 calls" } +struct foo { static int count; void print (int i, int j) { printf ("foo[%d][%d] = %d\n", i, j, x); } -- 2.34.1