Auto merge of #149788 - Sa4dUs:offload-cleanup, r=<try>

Move shared offload globals and define per-kernel globals once

Author: rust-bors[bot]

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -707,8 +707,7 @@ pub(crate) unsafe fn llvm_optimize(
     if cgcx.target_is_like_gpu && config.offload.contains(&config::Offload::Enable) {
         let cx =
             SimpleCx::new(module.module_llvm.llmod(), module.module_llvm.llcx, cgcx.pointer_size);
-        // For now we only support up to 10 kernels named kernel_0 ... kernel_9, a follow-up PR is
-        // introducing a proper offload intrinsic to solve this limitation.
+
         for func in cx.get_functions() {
             let offload_kernel = "offload-kernel";
             if attributes::has_string_attr(func, offload_kernel) {

compiler/rustc_codegen_llvm/src/base.rs

@@ -23,13 +23,14 @@ use rustc_middle::dep_graph;
 use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrs, SanitizerFnAttrs};
 use rustc_middle::mir::mono::Visibility;
 use rustc_middle::ty::TyCtxt;
-use rustc_session::config::DebugInfo;
+use rustc_session::config::{DebugInfo, Offload};
 use rustc_span::Symbol;
 use rustc_target::spec::SanitizerSet;
 
 use super::ModuleLlvm;
 use crate::attributes;
 use crate::builder::Builder;
+use crate::builder::gpu_offload::OffloadGlobals;
 use crate::context::CodegenCx;
 use crate::llvm::{self, Value};
 
@@ -85,6 +86,13 @@ pub(crate) fn compile_codegen_unit(
         let llvm_module = ModuleLlvm::new(tcx, cgu_name.as_str());
         {
             let mut cx = CodegenCx::new(tcx, cgu, &llvm_module);
+
+            if cx.sess().opts.unstable_opts.offload.contains(&Offload::Enable)
+                && !cx.sess().target.is_like_gpu
+            {
+                cx.offload_globals.replace(Some(OffloadGlobals::declare(&cx)));
+            }
+
             let mono_items = cx.codegen_unit.items_in_deterministic_order(cx.tcx);
             for &(mono_item, data) in &mono_items {
                 mono_item.predefine::<Builder<'_, '_, '_>>(