[llvm-bugs] [Bug 154702] Clang should inline pointers-to-members more aggresively with ranges

[LLVM Bugs via llvm-bugs]

Issue	154702
Summary	Clang should inline pointers-to-members more aggresively with ranges
Labels	clang
Assignees
Reporter	NamorNiradnug

    Consider the following example:
```c++
struct Foo {
    bool meow;
 std::vector<bool> boos;
};

bool Bar(const std::vector<Foo>& foos) {
 return std::ranges::any_of(
        foos
        | std::views::filter(&Foo::meow)
        | std::views::transform(&Foo::boos)
 | std::views::join,
        std::identity{}
    );
}
```

Clang doesn't inline the `any_of` and call it instead of inlining it:
```asm
Bar(std::vector<Foo, std::allocator<Foo>> const&):
        sub rsp, 40
        mov     qword ptr [rsp + 8], rdi
        mov     qword ptr [rsp + 16], 0
        mov     qword ptr [rsp + 24], -1
        mov qword ptr [rsp + 32], 8
        lea     rdi, [rip + std::ranges::any_of]
 lea     rsi, [rsp + 8]
        call    bool std::ranges::__any_of_fn::operator()<std::ranges::join_view<std::ranges::transform_view<std::ranges::filter_view<std::ranges::ref_view<std::vector<Foo, std::allocator<Foo>> const>, bool Foo::*>, std::vector<bool, std::allocator<bool>> Foo::*>>, std::identity, std::identity>(T&&, std::identity, T0) const
        add     rsp, 40
        ret
```

But after changing even one of `&Foo::meow` or `&Foo::boos` to a lambda `Bar` gets inlined:
```c++
bool BarInlined(const std::vector<Foo>& foos) {
 return std::ranges::any_of(
        foos
        | std::views::filter([] (const auto& foo) { return foo.meow; })
        | std::views::transform(&Foo::boos)
        | std::views::join,
 std::identity{}
    );
}

bool BarAlsoInlined(const std::vector<Foo>& foos) {
    return std::ranges::any_of(
        foos
        | std::views::filter(&Foo::meow)
        | std::views::transform([] (const auto& foo) -> const auto& { return foo.boos; })
        | std::views::join,
        std::identity{}
    );
}
```

GCC inlines the `any_of` for all the examples.

Godbolt: https://godbolt.org/z/z6qq87YTd

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