From ca935ddbf104b8b48eea8106f19e6a87f628d897 Mon Sep 17 00:00:00 2001
From: bjorn3 <bjorn3@users.noreply.github.com>
Date: Wed, 30 Jun 2021 18:39:28 +0200
Subject: [PATCH] Make tcx.stable_crate_id() faster

---
 compiler/rustc_middle/src/ty/context.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index abf839711b332..9c98592c86518 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1299,8 +1299,12 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     #[inline]
-    pub fn stable_crate_id(self, cnum: CrateNum) -> StableCrateId {
-        self.def_path_hash(cnum.as_def_id()).stable_crate_id()
+    pub fn stable_crate_id(self, crate_num: CrateNum) -> StableCrateId {
+        if crate_num == LOCAL_CRATE {
+            self.sess.local_stable_crate_id()
+        } else {
+            self.cstore.stable_crate_id_untracked(crate_num)
+        }
     }
 
     pub fn def_path_debug_str(self, def_id: DefId) -> String {