[Bug other/94403] New: Missed optimization bswap

[boris_oncev at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94403

Bug ID: 94403
   Summary: Missed optimization bswap
   Product: gcc
   Version: 10.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: other
  Assignee: unassigned at gcc dot gnu.org
  Reporter: boris_oncev at hotmail dot com
  Target Milestone: ---

full code:
https://godbolt.org/z/zjNqYV

template 
auto reverse(T num) {

// misses optimization when num is int32_t OK for int64_t
auto* bytes = reinterpret_cast(&num);

// misses optimization for both 32 and 64 bit ints
//auto* bytes = reinterpret_cast(&num);

constexpr auto size = sizeof(num);
for (int i = 0; i < size / 2; i++) {
std::swap(bytes[i], bytes[size-i-1]);
}

return num;
}

[Bug other/94403] Missed optimization bswap

[boris_oncev at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94403

Boris  changed:

   What|Removed |Added

 Status|UNCONFIRMED |RESOLVED
 Resolution|--- |DUPLICATE

--- Comment #1 from Boris  ---
Very similar

*** This bug has been marked as a duplicate of bug 93328 ***

[Bug tree-optimization/93328] missed optimization opportunity in deserialization code

[boris_oncev at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93328

Boris  changed:

   What|Removed |Added

 CC||boris_oncev at hotmail dot com

--- Comment #4 from Boris  ---
*** Bug 94403 has been marked as a duplicate of this bug. ***

[Bug tree-optimization/93328] missed optimization opportunity in deserialization code

[boris_oncev at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93328

--- Comment #5 from Boris  ---
full code:
https://godbolt.org/z/zjNqYV

template 
auto reverse(T num) {

// misses optimization when num is int32_t OK for int64_t
auto* bytes = reinterpret_cast(&num);

// misses optimization for both 32 and 64 bit ints
//auto* bytes = reinterpret_cast(&num);

constexpr auto size = sizeof(num);
for (int i = 0; i < size / 2; i++) {
std::swap(bytes[i], bytes[size-i-1]);
}

return num;
}

[Bug c++/95164] New: ICE regression starting with 9.3

[boris_oncev at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95164

Bug ID: 95164
   Summary: ICE regression starting with 9.3
   Product: gcc
   Version: 10.1.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: boris_oncev at hotmail dot com
  Target Milestone: ---

Reproduction code on godbolt, showing ICE on 9.3 & 10.1 but works fine on 9.2

https://godbolt.org/z/-Dr7Lc

#include 

struct A { };
struct B {
  A a;
};

struct C { };
struct D {
  C c;
  B b;
};

struct E {
  D d;
};

template
struct F {
  F() {
A a;
A& a2 = a;

std::vector return_values;
return_values.push_back({ {C{}, {B{a2}}} });
  }
};

[Bug c++/96115] New: Char literal, decays to a pointer when passed to function pointer

[boris_oncev at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96115

Bug ID: 96115
   Summary: Char literal, decays to a pointer when passed to
function pointer
   Product: gcc
   Version: 10.1.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: boris_oncev at hotmail dot com
  Target Milestone: ---

Example code:
struct SL{
template 
SL(const char (&Str)[N]) {}
};

int foo(SL x) {
return 2;
}

int main() {
int (*f)(SL) = &foo;
foo("asd"); // works fine
f("asd"); // error could not convert '(const char*) to SL
}

Godbot link:
https://godbolt.org/z/vo8lOf

works on other compilers clang, msvc and icc

[Bug c++/86648] New: [9 Regression] ICE on class template argument deduction

[boris_oncev at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86648

Bug ID: 86648
   Summary: [9 Regression] ICE on class template argument
deduction
   Product: gcc
   Version: 9.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: boris_oncev at hotmail dot com
  Target Milestone: ---

On compiler explorer using the gcc (trunk) compiler I get an ICE.
https://godbolt.org/g/NPtXxH

The same code works on earlier versions 8.1 and 7.3 and Clang.

```
#include 

template 
struct Foo {
static constexpr int a = 3;
};

template
struct Bar {
static constexpr std::tuple baz = { 1, 2, Foo::a };
// add  ^ 
// to make it compile
};

int main() {
return std::get<2>(Bar::baz);
}
```

[Bug c++/86648] [9 Regression] ICE on class template argument deduction

[boris_oncev at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86648

--- Comment #2 from Boris  ---
(In reply to Marek Polacek from comment #1)
> I don't see any ICE with -std=c++17.

Did you try it on godbolt, or locally(maybe you have newer version than
godbolt) ?

[Bug c++/107282] New: ICE on valid code template + overloaded + visit

[boris_oncev at hotmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107282

Bug ID: 107282
   Summary: ICE on valid code template + overloaded + visit
   Product: gcc
   Version: 13.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: boris_oncev at hotmail dot com
  Target Milestone: ---

ICE on >=C++17 on all supported versions

https://godbolt.org/z/5exMcrhYz