From: Michael Woerister <michaelwoerister@posteo>
Date: Fri, 13 Dec 2019 13:46:10 +0000 (+0100)
Subject: Use 'relaxed' memory ordering for simple atomic counters in dep-graph.
X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=996511a45655e452ec3132094e08dcbebee36a67;p=rust.git

Use 'relaxed' memory ordering for simple atomic counters in dep-graph.
---

diff --git a/src/librustc/dep_graph/graph.rs b/src/librustc/dep_graph/graph.rs
index 0616f00b8c4..0148997ca9e 100644
--- a/src/librustc/dep_graph/graph.rs
+++ b/src/librustc/dep_graph/graph.rs
@@ -497,8 +497,8 @@ pub fn edge_deduplication_data(&self) -> Option<(u64, u64)> {
             let current_dep_graph = &self.data.as_ref().unwrap().current;
 
             Some((
-                current_dep_graph.total_read_count.load(SeqCst),
-                current_dep_graph.total_duplicate_read_count.load(SeqCst),
+                current_dep_graph.total_read_count.load(Relaxed),
+                current_dep_graph.total_duplicate_read_count.load(Relaxed),
             ))
         } else {
             None
@@ -1111,7 +1111,7 @@ fn read_index(&self, source: DepNodeIndex) {
             if let Some(task_deps) = icx.task_deps {
                 let mut task_deps = task_deps.lock();
                 if cfg!(debug_assertions) {
-                    self.current.total_read_count.fetch_add(1, SeqCst);
+                    self.current.total_read_count.fetch_add(1, Relaxed);
                 }
                 if task_deps.read_set.insert(source) {
                     task_deps.reads.push(source);
@@ -1129,7 +1129,7 @@ fn read_index(&self, source: DepNodeIndex) {
                         }
                     }
                 } else if cfg!(debug_assertions) {
-                    self.current.total_duplicate_read_count.fetch_add(1, SeqCst);
+                    self.current.total_duplicate_read_count.fetch_add(1, Relaxed);
                 }
             }
         })