improve inline addition logic

Author: Shourya742

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -29,7 +29,7 @@ use crate::errors::{
     DynamicLinkingWithLTO, LlvmError, LtoBitcodeFromRlib, LtoDisallowed, LtoDylib, LtoProcMacro,
 };
 use crate::llvm::AttributePlace::Function;
-use crate::llvm::{self, build_string, get_value_name};
+use crate::llvm::{self, build_string};
 use crate::{LlvmCodegenBackend, ModuleLlvm, SimpleCx, attributes};
 
 /// We keep track of the computed LTO cache keys from the previous
@@ -669,23 +669,26 @@ pub(crate) fn run_pass_manager(
             SimpleCx::new(module.module_llvm.llmod(), &module.module_llvm.llcx, cgcx.pointer_size);
 
         for function in cx.get_functions() {
-            let name = get_value_name(function);
-            let name = std::str::from_utf8(name).unwrap();
+            let enzyme_marker = CString::new("enzyme_marker").unwrap();
+            let marker_ptr = enzyme_marker.as_ptr();
 
-            if name.starts_with("__enzyme") {
-                // Ensure `noinline` is present before replacing it.
-                // This is not strictly necessary for correctness, but serves as a sanity check
-                // in case the autodiff pass stops injecting `noinline` in the future.
+            if attributes::has_string_attr(function, marker_ptr) {
+                // Sanity check: Ensure 'noinline' is present before replacing it.
                 assert!(
                     !attributes::has_attr(function, Function, llvm::AttributeKind::NoInline),
                     "Expected __enzyme function to have 'noinline' before adding 'alwaysinline'"
                 );
 
-                // Removing inline from function.
                 attributes::remove_from_llfn(function, Function, llvm::AttributeKind::NoInline);
+                attributes::remove_string_attr_from_llfn(function, marker_ptr);
 
-                let attr = llvm::AttributeKind::AlwaysInline.create_attr(cx.llcx);
-                attributes::apply_to_llfn(function, Function, &[attr]);
+                assert!(
+                    !attributes::has_string_attr(function, marker_ptr),
+                    "Expected function to not have 'enzyme_marker'"
+                );
+
+                let always_inline = llvm::AttributeKind::AlwaysInline.create_attr(cx.llcx);
+                attributes::apply_to_llfn(function, Function, &[always_inline]);
             }
         }