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From: "magnus.hegdahl at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/113676] [12 Regression] Miscompilation tree-vrp __builtin_unreachable Date: Wed, 31 Jan 2024 09:13:44 +0000 [thread overview] Message-ID: <bug-113676-4-USlhl64DcM@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-113676-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113676 --- Comment #2 from Magnus Hokland Hegdahl <magnus.hegdahl at gmail dot com> --- Hi, here's a version that doesn't need -std=c++20 or argv: https://godbolt.org/z/Y9ooY998e #include <vector> constexpr auto bit_ceil(unsigned x) -> unsigned { if (x <= 1) return 1U; int w = 32 - __builtin_clz(x - 1); return 1U << w; } int main(int argc, char **) { auto rounded_n = bit_ceil(static_cast<unsigned>(argc + 1)); auto a = std::vector<int>(2UL * rounded_n); for (std::size_t i = rounded_n; i-- > 1;) { if (!(0 < i && i < rounded_n)) __builtin_unreachable(); a[i] = 0; } } Exact compile command used with g++-12 (GCC) 12.3.0 on arch linux, x86_64: g++-12 -O1 -ftree-vrp main.cpp
next prev parent reply other threads:[~2024-01-31 9:13 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-01-31 0:54 [Bug tree-optimization/113676] New: " magnus.hegdahl at gmail dot com 2024-01-31 1:13 ` [Bug tree-optimization/113676] [11/12 Regression] " pinskia at gcc dot gnu.org 2024-01-31 8:25 ` [Bug tree-optimization/113676] [12 " rguenth at gcc dot gnu.org 2024-01-31 9:13 ` magnus.hegdahl at gmail dot com [this message] 2024-01-31 9:40 ` jakub at gcc dot gnu.org 2024-01-31 9:44 ` jakub at gcc dot gnu.org 2024-06-20 9:14 ` rguenth at gcc dot gnu.org
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