https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113662
Bug ID: 113662
Summary: [13/14 Regression] Wrong code for std::sort with fancy
pointer
Product: gcc
Version: 13.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ostash at ostash dot kiev.ua
Target Milestone: ---
Hello,
For the following snippet compiled with "-O3 -std=c++20"
---
#include <boost/container/vector.hpp>
#include <boost/interprocess/offset_ptr.hpp>
#include <algorithm>
#include <iostream>
struct Foo
{
public:
uint32_t m1;
uint32_t m2;
uint8_t m3;
};
bool operator<(const Foo& lhs, const Foo& rhs)
{
return lhs.m1 < rhs.m1;
}
template <typename T>
class MyAllocator
{
public:
using value_type = T;
using pointer = boost::interprocess::offset_ptr<T>;
boost::interprocess::offset_ptr<T> allocate( std::size_t n ) {
return boost::interprocess::offset_ptr<T>(a.allocate(n));
}
void deallocate( boost::interprocess::offset_ptr<T> p, std::size_t n ) {
a.deallocate(p.get(), n);
}
std::allocator<T> a;
};
int main()
{
boost::container::vector<Foo, MyAllocator<Foo>> vec;
vec.emplace_back().m1 = 4748;
vec.emplace_back().m1 = 4687;
vec.emplace_back().m1 = 4717;
vec.emplace_back().m1 = 4779;
std::cout << "before: " << vec.size() << '\n';
for (const auto& x : vec)
std::cout << std::to_string(x.m1) << '\n';
std::sort(vec.begin(), vec.end());
std::cout << "after: " << vec.size() << '\n';
for (const auto& x : vec)
std::cout << std::to_string(x.m1) << '\n';
}
---
we receive the following output:
---
before: 4
4748
4687
4717
4779
after: 4
4687
4717
4717
4779
---
I've managed to bisect this issue to the following commit:
429a7a88438cc80e7c58d9f63d44838089899b12 is the first bad commit
commit 429a7a88438cc80e7c58d9f63d44838089899b12
Author: Andrew MacLeod <amacl...@redhat.com>
Date: Tue Mar 28 12:16:34 2023 -0400
Add recursive GORI recompuations with a depth limit.
PR tree-optimization/109154
gcc/
* gimple-range-gori.cc (gori_compute::may_recompute_p): Add depth
limit.
* gimple-range-gori.h (may_recompute_p): Add depth param.
* params.opt (ranger-recompute-depth): New param.
gcc/testsuite/
* gcc.dg/Walloca-13.c: Remove bogus warning that is now fixed.
gcc/gimple-range-gori.cc | 30 ++++++++++++++++++++++--------
gcc/gimple-range-gori.h | 4 ++--
gcc/params.opt | 5 +++++
gcc/testsuite/gcc.dg/Walloca-13.c | 2 +-
4 files changed, 30 insertions(+), 11 deletions(-)
I tried different versions of Boost to ensure that the problem is not coming
from offset_ptr. It looks like that it is possible to reproduce issue with "-O2
-ftree-partial-pre".
Everything works fine with std::vector or std::allocator.
I'd be glad to perform other tests if needed.
