llvm/llvm-project

[clang++] operator==(vector of long, vector of long) -> vector of long long

Open

#132.604 geöffnet am 23. März 2025

Auf GitHub ansehen
 (22 Kommentare) (0 Reaktionen) (1 zugewiesene Person)C++ (10.782 Forks)batch import
ABIclang:frontenddiverges-from:gccgood first issue

Repository-Metriken

Stars
 (26.378 Stars)
PR-Merge-Metriken
 (Durchschn. Merge 1T 2h) (1.000 gemergte PRs in 30 T)

Beschreibung

When comparing two variables of vector of long, clang++ returns a vector of long long, inconsistent with g++. https://godbolt.org/z/db9zT6f4r

#include <type_traits>

using T [[gnu::vector_size(sizeof(long))]] = long;

static_assert(std::is_same_v<std::remove_reference_t<decltype((T{} == T{})[0])>, long>);

This makes the following code fails to compile with clang++ with the compilation options -march=x86-64-v4 -std=c++20 (previously reported as gcc bugzilla 118546). Online link: https://godbolt.org/z/sxqsKrv9e .

#include <experimental/simd>
#include <cstdint>

using deduce_t_element = std::experimental::simd<
    std::uint64_t,
    std::experimental::simd_abi::deduce_t<std::uint64_t, 4>
>;

auto f(deduce_t_element e) {
    return e == 0;
}

Contributor Guide