cleanup

Author: ZuseZ4

compiler/rustc_codegen_llvm/src/builder/gpu_offload.rs

@@ -288,7 +288,7 @@ impl KernelArgsTy {
 pub(crate) struct OffloadKernelGlobals<'ll> {
     pub offload_sizes: &'ll llvm::Value,
     pub memtransfer_types: &'ll llvm::Value,
-    pub region_id: &'ll llvm::Value,
+    pub region_id: Option<&'ll llvm::Value>,
     pub offload_entry: Option<&'ll llvm::Value>,
 }
 
@@ -391,11 +391,11 @@ pub(crate) fn gen_define_handling<'ll>(
     // Next: For each function, generate these three entries. A weak constant,
     // the llvm.rodata entry name, and  the llvm_offload_entries value
 
-    let name = format!(".{symbol}.region_id");
-    let initializer = cx.get_const_i8(0);
-    let region_id = add_global(&cx, &name, initializer, WeakAnyLinkage);
+    let (offload_entry, region_id) = if !host {
+        let name = format!(".{symbol}.region_id");
+        let initializer = cx.get_const_i8(0);
+        let region_id = add_global(&cx, &name, initializer, WeakAnyLinkage);
 
-    let offload_entry = if !host {
         let c_entry_name = CString::new(symbol.clone()).unwrap();
         let c_val = c_entry_name.as_bytes_with_nul();
         let offload_entry_name = format!(".offloading.entry_name.{symbol}");
@@ -419,9 +419,9 @@ pub(crate) fn gen_define_handling<'ll>(
         llvm::set_alignment(offload_entry, Align::EIGHT);
         let c_section_name = CString::new("llvm_offload_entries").unwrap();
         llvm::set_section(offload_entry, &c_section_name);
-        Some(offload_entry)
+        (Some(offload_entry), Some(region_id))
     } else {
-        None
+        (None, None)
     };
 
     let result =
@@ -472,6 +472,8 @@ pub(crate) fn gen_call_handling<'ll, 'tcx>(
     args: &[&'ll Value],
     types: &[&Type],
     metadata: &[OffloadMetadata],
+    // TODO: fuse the device global part of offload_globals with offload_dims, s.t. they are set iff
+    // !host is given.
     offload_globals: &OffloadGlobals<'ll>,
     offload_dims: Option<&OffloadKernelDims<'ll>>,
     host: bool,
@@ -663,7 +665,7 @@ pub(crate) fn gen_call_handling<'ll, 'tcx>(
             cx.get_const_i64(u64::MAX), // MAX == -1.
             num_workgroups,
             threads_per_block,
-            region_id,
+            region_id.unwrap(),
             a5,
         ];
         // %41 = call i32 @__tgt_target_kernel(ptr @1, i64 -1, i32 2097152, i32 256, ptr @.kernel_1.region_id, ptr %kernel_args)