From 5c85d522d0083bee0d5fd7f26868fa0e62372485 Mon Sep 17 00:00:00 2001 From: Manuel Drehwald Date: Tue, 13 Jan 2026 09:52:36 -0800 Subject: [PATCH] Generate global openmp metadata to trigger llvm openmp-opt pass --- compiler/rustc_codegen_llvm/src/builder/gpu_offload.rs | 4 ++++ tests/codegen-llvm/gpu_offload/gpu_host.rs | 2 ++ 2 files changed, 6 insertions(+) diff --git a/compiler/rustc_codegen_llvm/src/builder/gpu_offload.rs b/compiler/rustc_codegen_llvm/src/builder/gpu_offload.rs index b8eb4f038216..084d40317ba8 100644 --- a/compiler/rustc_codegen_llvm/src/builder/gpu_offload.rs +++ b/compiler/rustc_codegen_llvm/src/builder/gpu_offload.rs @@ -55,6 +55,10 @@ impl<'ll> OffloadGlobals<'ll> { let init_ty = cx.type_func(&[], cx.type_void()); let init_rtls = declare_offload_fn(cx, "__tgt_init_all_rtls", init_ty); + // We want LLVM's openmp-opt pass to pick up and optimize this module, since it covers both + // openmp and offload optimizations. + llvm::add_module_flag_u32(cx.llmod(), llvm::ModuleFlagMergeBehavior::Max, "openmp", 51); + OffloadGlobals { launcher_fn, launcher_ty, diff --git a/tests/codegen-llvm/gpu_offload/gpu_host.rs b/tests/codegen-llvm/gpu_offload/gpu_host.rs index dcbd65b14427..27ff6f325aa0 100644 --- a/tests/codegen-llvm/gpu_offload/gpu_host.rs +++ b/tests/codegen-llvm/gpu_offload/gpu_host.rs @@ -104,3 +104,5 @@ pub fn _kernel_1(x: &mut [f32; 256]) { // CHECK-NEXT: call void @__tgt_unregister_lib(ptr nonnull %EmptyDesc) // CHECK-NEXT: ret void // CHECK-NEXT: } + +// CHECK: !{i32 7, !"openmp", i32 51}