diff --git a/library/core/src/option.rs b/library/core/src/option.rs
index 145c7ff5c3237..a6e7257448cb5 100644
--- a/library/core/src/option.rs
+++ b/library/core/src/option.rs
@@ -1671,7 +1671,8 @@ impl<T, E> Option<Result<T, E>> {
 }
 
 // This is a separate function to reduce the code size of .expect() itself.
-#[inline(never)]
+#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
+#[cfg_attr(feature = "panic_immediate_abort", inline)]
 #[cold]
 #[track_caller]
 const fn expect_failed(msg: &str) -> ! {
diff --git a/library/core/src/result.rs b/library/core/src/result.rs
index e6b8c8ec3385a..ab067d57d082a 100644
--- a/library/core/src/result.rs
+++ b/library/core/src/result.rs
@@ -1653,6 +1653,7 @@ impl<T> Result<T, T> {
 }
 
 // This is a separate function to reduce the code size of the methods
+#[cfg(not(feature = "panic_immediate_abort"))]
 #[inline(never)]
 #[cold]
 #[track_caller]
@@ -1660,6 +1661,18 @@ fn unwrap_failed(msg: &str, error: &dyn fmt::Debug) -> ! {
     panic!("{}: {:?}", msg, error)
 }
 
+// This is a separate function to avoid constructing a `dyn Debug`
+// that gets immediately thrown away, since vtables don't get cleaned up
+// by dead code elimination if a trait object is constructed even if it goes
+// unused
+#[cfg(feature = "panic_immediate_abort")]
+#[inline]
+#[cold]
+#[track_caller]
+fn unwrap_failed<T>(_msg: &str, _error: &T) -> ! {
+    panic!()
+}
+
 /////////////////////////////////////////////////////////////////////////////
 // Trait implementations
 /////////////////////////////////////////////////////////////////////////////
diff --git a/library/core/src/slice/index.rs b/library/core/src/slice/index.rs
index f722430354991..0298bba8d329e 100644
--- a/library/core/src/slice/index.rs
+++ b/library/core/src/slice/index.rs
@@ -27,35 +27,40 @@ where
     }
 }
 
-#[inline(never)]
+#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
+#[cfg_attr(feature = "panic_immediate_abort", inline)]
 #[cold]
 #[track_caller]
 fn slice_start_index_len_fail(index: usize, len: usize) -> ! {
     panic!("range start index {} out of range for slice of length {}", index, len);
 }
 
-#[inline(never)]
+#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
+#[cfg_attr(feature = "panic_immediate_abort", inline)]
 #[cold]
 #[track_caller]
 fn slice_end_index_len_fail(index: usize, len: usize) -> ! {
     panic!("range end index {} out of range for slice of length {}", index, len);
 }
 
-#[inline(never)]
+#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
+#[cfg_attr(feature = "panic_immediate_abort", inline)]
 #[cold]
 #[track_caller]
 fn slice_index_order_fail(index: usize, end: usize) -> ! {
     panic!("slice index starts at {} but ends at {}", index, end);
 }
 
-#[inline(never)]
+#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
+#[cfg_attr(feature = "panic_immediate_abort", inline)]
 #[cold]
 #[track_caller]
 fn slice_start_index_overflow_fail() -> ! {
     panic!("attempted to index slice from after maximum usize");
 }
 
-#[inline(never)]
+#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
+#[cfg_attr(feature = "panic_immediate_abort", inline)]
 #[cold]
 #[track_caller]
 fn slice_end_index_overflow_fail() -> ! {