From d081c20273cfafab0c896f66485495fa906a1f84 Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Tue, 23 Aug 2022 16:09:08 +0000
Subject: [PATCH] Compile functions from clif ir to object code in parallel

---
 src/base.rs       |  7 ++++---
 src/driver/aot.rs | 17 +++++++++--------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/src/base.rs b/src/base.rs
index 492e4882651..44c34d6c8cb 100644
--- a/src/base.rs
+++ b/src/base.rs
@@ -11,7 +11,7 @@ use crate::debuginfo::FunctionDebugContext;
 use crate::prelude::*;
 use crate::pretty_clif::CommentWriter;
 
-struct CodegenedFunction {
+pub(crate) struct CodegenedFunction {
     symbol_name: String,
     func_id: FuncId,
     func: Function,
@@ -19,6 +19,7 @@ struct CodegenedFunction {
     func_debug_cx: Option<FunctionDebugContext>,
 }
 
+#[cfg_attr(not(feature = "jit"), allow(dead_code))]
 pub(crate) fn codegen_and_compile_fn<'tcx>(
     tcx: TyCtxt<'tcx>,
     cx: &mut crate::CodegenCx,
@@ -35,7 +36,7 @@ pub(crate) fn codegen_and_compile_fn<'tcx>(
     compile_fn(cx, cached_context, module, codegened_func);
 }
 
-fn codegen_fn<'tcx>(
+pub(crate) fn codegen_fn<'tcx>(
     tcx: TyCtxt<'tcx>,
     cx: &mut crate::CodegenCx,
     cached_func: Function,
@@ -135,7 +136,7 @@ fn codegen_fn<'tcx>(
     CodegenedFunction { symbol_name, func_id, func, clif_comments, func_debug_cx }
 }
 
-fn compile_fn(
+pub(crate) fn compile_fn(
     cx: &mut crate::CodegenCx,
     cached_context: &mut Context,
     module: &mut dyn Module,
diff --git a/src/driver/aot.rs b/src/driver/aot.rs
index b8b325be71b..5a63786f070 100644
--- a/src/driver/aot.rs
+++ b/src/driver/aot.rs
@@ -271,18 +271,14 @@ fn module_codegen(
         cgu_name,
     );
     super::predefine_mono_items(tcx, &mut module, &mono_items);
-    let mut cached_context = Context::new();
+    let mut codegened_functions = vec![];
     for (mono_item, _) in mono_items {
         match mono_item {
             MonoItem::Fn(inst) => {
                 tcx.sess.time("codegen fn", || {
-                    crate::base::codegen_and_compile_fn(
-                        tcx,
-                        &mut cx,
-                        &mut cached_context,
-                        &mut module,
-                        inst,
-                    )
+                    let codegened_function =
+                        crate::base::codegen_fn(tcx, &mut cx, Function::new(), &mut module, inst);
+                    codegened_functions.push(codegened_function);
                 });
             }
             MonoItem::Static(def_id) => crate::constant::codegen_static(tcx, &mut module, def_id),
@@ -302,6 +298,11 @@ fn module_codegen(
     let cgu_name = cgu.name().as_str().to_owned();
 
     OngoingModuleCodegen::Async(std::thread::spawn(move || {
+        let mut cached_context = Context::new();
+        for codegened_func in codegened_functions {
+            crate::base::compile_fn(&mut cx, &mut cached_context, &mut module, codegened_func);
+        }
+
         let global_asm_object_file =
             crate::global_asm::compile_global_asm(&global_asm_config, &cgu_name, &cx.global_asm)?;