diff --git a/include/v8config.h b/include/v8config.h
index 5d11af0292..c79cd04e0f 100644
--- a/include/v8config.h
+++ b/include/v8config.h
@@ -346,7 +346,6 @@ path. Add it with -I<path> to the command line
 # define V8_HAS_ATTRIBUTE_NONNULL (__has_attribute(nonnull))
 # define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
 # define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
-# define V8_HAS_ATTRIBUTE_PRESERVE_MOST (__has_attribute(preserve_most))
 # define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
 # define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
     (__has_attribute(warn_unused_result))
@@ -505,21 +504,6 @@ path. Add it with -I<path> to the command line
 #endif
 
 
-// A macro used to change the calling conventions to preserve all registers (no
-// caller-saved registers). Use this for cold functions called from hot
-// functions.
-// Note: The attribute is considered experimental, so apply with care. Also,
-// "preserve_most" is currently not handling the return value correctly, so only
-// use it for functions returning void (see https://reviews.llvm.org/D141020).
-// Use like:
-//   V8_NOINLINE V8_PRESERVE_MOST void UnlikelyMethod();
-#if V8_HAS_ATTRIBUTE_PRESERVE_MOST
-# define V8_PRESERVE_MOST __attribute__((preserve_most))
-#else
-# define V8_PRESERVE_MOST /* NOT SUPPORTED */
-#endif
-
-
 // A macro (V8_DEPRECATED) to mark classes or functions as deprecated.
 #if defined(V8_DEPRECATION_WARNINGS)
 # define V8_DEPRECATED(message) [[deprecated(message)]]
diff --git a/src/codegen/x64/assembler-x64.h b/src/codegen/x64/assembler-x64.h
index 1b34ae073a..afc5798482 100644
--- a/src/codegen/x64/assembler-x64.h
+++ b/src/codegen/x64/assembler-x64.h
@@ -2131,7 +2131,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   }
 
   // Code emission.
-  V8_NOINLINE V8_PRESERVE_MOST void GrowBuffer();
+  void GrowBuffer();
 
   template <typename T>
   static uint8_t* emit(uint8_t* __restrict pc, T t) {