Rollup merge of #73398 - oli-obk:const_raw_ptr_cmp, r=varkor,RalfJung,nagisa

A way forward for pointer equality in const eval

r? @varkor on the first commit and @RalfJung on the second commit

cc #53020

1 files changed, 17 insertions, 0 deletions

diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs
index 21ba2b5abcf..c69aafe687c 100644
--- a/src/libcore/slice/mod.rs
+++ b/src/libcore/slice/mod.rs
@@ -5956,10 +5956,18 @@ where
             return false;
         }
 
+        #[cfg(bootstrap)]
         if self.as_ptr() == other.as_ptr() {
             return true;
         }
 
+        // While performance would suffer if `guaranteed_eq` just returned `false`
+        // for all arguments, correctness and return value of this function are not affected.
+        #[cfg(not(bootstrap))]
+        if self.as_ptr().guaranteed_eq(other.as_ptr()) {
+            return true;
+        }
+
         self.iter().zip(other.iter()).all(|(x, y)| x == y)
     }
 }
@@ -5973,9 +5981,18 @@ where
         if self.len() != other.len() {
             return false;
         }
+
+        #[cfg(bootstrap)]
         if self.as_ptr() == other.as_ptr() {
             return true;
         }
+
+        // While performance would suffer if `guaranteed_eq` just returned `false`
+        // for all arguments, correctness and return value of this function are not affected.
+        #[cfg(not(bootstrap))]
+        if self.as_ptr().guaranteed_eq(other.as_ptr()) {
+            return true;
+        }
         unsafe {
             let size = mem::size_of_val(self);
             memcmp(self.as_ptr() as *const u8, other.as_ptr() as *const u8, size) == 0