diff --git a/compiler-rt/lib/asan/asan_interceptors_memintrinsics.cpp b/compiler-rt/lib/asan/asan_interceptors_memintrinsics.cpp
index 4e4ea71..9d14524 100644
--- a/compiler-rt/lib/asan/asan_interceptors_memintrinsics.cpp
+++ b/compiler-rt/lib/asan/asan_interceptors_memintrinsics.cpp
@@ -11,8 +11,6 @@
 // ASan versions of memcpy, memmove, and memset.
 //===---------------------------------------------------------------------===//
 
-#define SANITIZER_COMMON_NO_REDEFINE_BUILTINS
-
 #include "asan_interceptors_memintrinsics.h"
 
 #include "asan_interceptors.h"
diff --git a/compiler-rt/lib/hwasan/hwasan_interceptors.cpp b/compiler-rt/lib/hwasan/hwasan_interceptors.cpp
index bffb4e0..2610933 100644
--- a/compiler-rt/lib/hwasan/hwasan_interceptors.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_interceptors.cpp
@@ -14,8 +14,6 @@
 // sanitizer_common/sanitizer_common_interceptors.h
 //===----------------------------------------------------------------------===//
 
-#define SANITIZER_COMMON_NO_REDEFINE_BUILTINS
-
 #include "hwasan.h"
 #include "hwasan_allocator.h"
 #include "hwasan_checks.h"
diff --git a/compiler-rt/lib/interception/tests/CMakeLists.txt b/compiler-rt/lib/interception/tests/CMakeLists.txt
index f6840e1..688edc3 100644
--- a/compiler-rt/lib/interception/tests/CMakeLists.txt
+++ b/compiler-rt/lib/interception/tests/CMakeLists.txt
@@ -17,7 +17,6 @@
   -I${COMPILER_RT_SOURCE_DIR}/include
   -I${COMPILER_RT_SOURCE_DIR}/lib
   -I${COMPILER_RT_SOURCE_DIR}/lib/interception
-  -DSANITIZER_COMMON_NO_REDEFINE_BUILTINS
   -fno-rtti
   -O2
   -Werror=sign-compare)
diff --git a/compiler-rt/lib/memprof/memprof_interceptors_memintrinsics.cpp b/compiler-rt/lib/memprof/memprof_interceptors_memintrinsics.cpp
index 56bd116..dae2ab5 100644
--- a/compiler-rt/lib/memprof/memprof_interceptors_memintrinsics.cpp
+++ b/compiler-rt/lib/memprof/memprof_interceptors_memintrinsics.cpp
@@ -11,8 +11,6 @@
 // MemProf versions of memcpy, memmove, and memset.
 //===---------------------------------------------------------------------===//
 
-#define SANITIZER_COMMON_NO_REDEFINE_BUILTINS
-
 #include "memprof_interceptors_memintrinsics.h"
 
 #include "memprof_interceptors.h"
diff --git a/compiler-rt/lib/msan/msan_interceptors.cpp b/compiler-rt/lib/msan/msan_interceptors.cpp
index 6f57c33..96abc47 100644
--- a/compiler-rt/lib/msan/msan_interceptors.cpp
+++ b/compiler-rt/lib/msan/msan_interceptors.cpp
@@ -14,8 +14,6 @@
 // sanitizer_common/sanitizer_common_interceptors.h
 //===----------------------------------------------------------------------===//
 
-#define SANITIZER_COMMON_NO_REDEFINE_BUILTINS
-
 #include "interception/interception.h"
 #include "msan.h"
 #include "msan_chained_origin_depot.h"
diff --git a/compiler-rt/lib/sanitizer_common/CMakeLists.txt b/compiler-rt/lib/sanitizer_common/CMakeLists.txt
index bfa59da..c4fdc7a 100644
--- a/compiler-rt/lib/sanitizer_common/CMakeLists.txt
+++ b/compiler-rt/lib/sanitizer_common/CMakeLists.txt
@@ -172,7 +172,6 @@
   sanitizer_procmaps.h
   sanitizer_ptrauth.h
   sanitizer_quarantine.h
-  sanitizer_redefine_builtins.h
   sanitizer_report_decorator.h
   sanitizer_ring_buffer.h
   sanitizer_signal_interceptors.inc
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors_memintrinsics.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors_memintrinsics.inc
index 52e489d..e6b967c 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors_memintrinsics.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors_memintrinsics.inc
@@ -9,10 +9,6 @@
 // Memintrinsic function interceptors for tools like AddressSanitizer,
 // ThreadSanitizer, MemorySanitizer, etc.
 //
-// These interceptors are part of the common interceptors, but separated out so
-// that implementations may add them, if necessary, to a separate source file
-// that should define SANITIZER_COMMON_NO_REDEFINE_BUILTINS at the top.
-//
 // This file should be included into the tool's memintrinsic interceptor file,
 // which has to define its own macros:
 //   COMMON_INTERCEPTOR_ENTER
@@ -24,10 +20,6 @@
 //   COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED
 //===----------------------------------------------------------------------===//
 
-#ifdef SANITIZER_REDEFINE_BUILTINS_H
-#error "Define SANITIZER_COMMON_NO_REDEFINE_BUILTINS in .cpp file"
-#endif
-
 #include "interception/interception.h"
 #include "sanitizer_platform_interceptors.h"
 
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interface.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interface.inc
index 557207f..37efb57 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interface.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interface.inc
@@ -46,7 +46,3 @@
 INTERFACE_FUNCTION(__sanitizer_print_memory_profile)
 INTERFACE_WEAK_FUNCTION(__sanitizer_free_hook)
 INTERFACE_WEAK_FUNCTION(__sanitizer_malloc_hook)
-// Memintrinsic functions.
-INTERFACE_FUNCTION(__sanitizer_internal_memcpy)
-INTERFACE_FUNCTION(__sanitizer_internal_memmove)
-INTERFACE_FUNCTION(__sanitizer_internal_memset)
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h b/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h
index e5dd65a..95f4760 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h
@@ -13,7 +13,6 @@
 #define SANITIZER_DEFS_H
 
 #include "sanitizer_platform.h"
-#include "sanitizer_redefine_builtins.h"
 
 #ifndef SANITIZER_DEBUG
 # define SANITIZER_DEBUG 0
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_libc.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_libc.cpp
index 4a6fa5e..d3076f0 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_libc.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_libc.cpp
@@ -10,9 +10,6 @@
 // run-time libraries. See sanitizer_libc.h for details.
 //===----------------------------------------------------------------------===//
 
-// Do not redefine builtins; this file is defining the builtin replacements.
-#define SANITIZER_COMMON_NO_REDEFINE_BUILTINS
-
 #include "sanitizer_allocator_internal.h"
 #include "sanitizer_common.h"
 #include "sanitizer_libc.h"
@@ -49,10 +46,7 @@
   return 0;
 }
 
-extern "C" {
-SANITIZER_INTERFACE_ATTRIBUTE void *__sanitizer_internal_memcpy(void *dest,
-                                                                const void *src,
-                                                                uptr n) {
+void *internal_memcpy(void *dest, const void *src, uptr n) {
   char *d = (char*)dest;
   const char *s = (const char *)src;
   for (uptr i = 0; i < n; ++i)
@@ -60,8 +54,7 @@
   return dest;
 }
 
-SANITIZER_INTERFACE_ATTRIBUTE void *__sanitizer_internal_memmove(
-    void *dest, const void *src, uptr n) {
+void *internal_memmove(void *dest, const void *src, uptr n) {
   char *d = (char*)dest;
   const char *s = (const char *)src;
   sptr i, signed_n = (sptr)n;
@@ -79,8 +72,7 @@
   return dest;
 }
 
-SANITIZER_INTERFACE_ATTRIBUTE void *__sanitizer_internal_memset(void *s, int c,
-                                                                uptr n) {
+void *internal_memset(void* s, int c, uptr n) {
   // Optimize for the most performance-critical case:
   if ((reinterpret_cast<uptr>(s) % 16) == 0 && (n % 16) == 0) {
     u64 *p = reinterpret_cast<u64*>(s);
@@ -103,7 +95,6 @@
   }
   return s;
 }
-}  // extern "C"
 
 uptr internal_strcspn(const char *s, const char *reject) {
   uptr i;
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_libc.h b/compiler-rt/lib/sanitizer_common/sanitizer_libc.h
index e881db2..39a2126 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_libc.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_libc.h
@@ -24,33 +24,15 @@
 
 // internal_X() is a custom implementation of X() for use in RTL.
 
-extern "C" {
-// These are used as builtin replacements; see sanitizer_redefine_builtins.h.
-// In normal runtime code, use the __sanitizer::internal_X() aliases instead.
-SANITIZER_INTERFACE_ATTRIBUTE void *__sanitizer_internal_memcpy(void *dest,
-                                                                const void *src,
-                                                                uptr n);
-SANITIZER_INTERFACE_ATTRIBUTE void *__sanitizer_internal_memmove(
-    void *dest, const void *src, uptr n);
-SANITIZER_INTERFACE_ATTRIBUTE void *__sanitizer_internal_memset(void *s, int c,
-                                                                uptr n);
-}  // extern "C"
-
 // String functions
 s64 internal_atoll(const char *nptr);
 void *internal_memchr(const void *s, int c, uptr n);
 void *internal_memrchr(const void *s, int c, uptr n);
 int internal_memcmp(const void* s1, const void* s2, uptr n);
-ALWAYS_INLINE void *internal_memcpy(void *dest, const void *src, uptr n) {
-  return __sanitizer_internal_memcpy(dest, src, n);
-}
-ALWAYS_INLINE void *internal_memmove(void *dest, const void *src, uptr n) {
-  return __sanitizer_internal_memmove(dest, src, n);
-}
+void *internal_memcpy(void *dest, const void *src, uptr n);
+void *internal_memmove(void *dest, const void *src, uptr n);
 // Should not be used in performance-critical places.
-ALWAYS_INLINE void *internal_memset(void *s, int c, uptr n) {
-  return __sanitizer_internal_memset(s, c, n);
-}
+void *internal_memset(void *s, int c, uptr n);
 char* internal_strchr(const char *s, int c);
 char *internal_strchrnul(const char *s, int c);
 int internal_strcmp(const char *s1, const char *s2);
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_redefine_builtins.h b/compiler-rt/lib/sanitizer_common/sanitizer_redefine_builtins.h
deleted file mode 100644
index 13dc7d5..0000000
--- a/compiler-rt/lib/sanitizer_common/sanitizer_redefine_builtins.h
+++ /dev/null
@@ -1,27 +0,0 @@
-//===-- sanitizer_redefine_builtins.h ---------------------------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// Redefine builtin functions to use internal versions. This is needed where
-// compiler optimizations end up producing unwanted libcalls!
-//
-//===----------------------------------------------------------------------===//
-#ifndef SANITIZER_COMMON_NO_REDEFINE_BUILTINS
-#ifndef SANITIZER_REDEFINE_BUILTINS_H
-#define SANITIZER_REDEFINE_BUILTINS_H
-
-// The asm hack only works with GCC and Clang.
-#if !defined(_MSC_VER) || defined(__clang__)
-
-asm("memcpy = __sanitizer_internal_memcpy");
-asm("memmove = __sanitizer_internal_memmove");
-asm("memset = __sanitizer_internal_memset");
-
-#endif  // !_MSC_VER || __clang__
-
-#endif  // SANITIZER_REDEFINE_BUILTINS_H
-#endif  // SANITIZER_COMMON_NO_REDEFINE_BUILTINS
diff --git a/compiler-rt/lib/sanitizer_common/tests/CMakeLists.txt b/compiler-rt/lib/sanitizer_common/tests/CMakeLists.txt
index 2b85372..40aa8e7 100644
--- a/compiler-rt/lib/sanitizer_common/tests/CMakeLists.txt
+++ b/compiler-rt/lib/sanitizer_common/tests/CMakeLists.txt
@@ -69,7 +69,6 @@
   -I${COMPILER_RT_SOURCE_DIR}/include
   -I${COMPILER_RT_SOURCE_DIR}/lib
   -I${COMPILER_RT_SOURCE_DIR}/lib/sanitizer_common
-  -DSANITIZER_COMMON_NO_REDEFINE_BUILTINS
   -fno-rtti
   -O2
   -Werror=sign-compare
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors_memintrinsics.cpp b/compiler-rt/lib/tsan/rtl/tsan_interceptors_memintrinsics.cpp
index c8b6b2e..6a2a429 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors_memintrinsics.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors_memintrinsics.cpp
@@ -10,8 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define SANITIZER_COMMON_NO_REDEFINE_BUILTINS
-
 #include "tsan_interceptors.h"
 #include "tsan_interface.h"
 
diff --git a/compiler-rt/lib/ubsan_minimal/CMakeLists.txt b/compiler-rt/lib/ubsan_minimal/CMakeLists.txt
index 07e96a7..504dd3b 100644
--- a/compiler-rt/lib/ubsan_minimal/CMakeLists.txt
+++ b/compiler-rt/lib/ubsan_minimal/CMakeLists.txt
@@ -6,9 +6,7 @@
 
 include_directories(..)
 
-set(UBSAN_CFLAGS
-  ${SANITIZER_COMMON_CFLAGS}
-  -DSANITIZER_COMMON_NO_REDEFINE_BUILTINS)
+set(UBSAN_CFLAGS ${SANITIZER_COMMON_CFLAGS})
 append_rtti_flag(OFF UBSAN_CFLAGS)
 
 set(UBSAN_LINK_FLAGS ${SANITIZER_COMMON_LINK_FLAGS})
diff --git a/compiler-rt/test/asan/TestCases/Linux/check_memcpy.c b/compiler-rt/test/asan/TestCases/Linux/check_memcpy.c
deleted file mode 100644
index d5fee16..0000000
--- a/compiler-rt/test/asan/TestCases/Linux/check_memcpy.c
+++ /dev/null
@@ -1,8 +0,0 @@
-// Verify runtime doesn't contain compiler-emitted memcpy/memmove calls.
-//
-// REQUIRES: shared_unwind, x86_64-target-arch
-
-// RUN: %clang_asan -O1 %s -o %t
-// RUN: llvm-objdump -d -l %t | FileCheck --implicit-check-not="{{(callq|jmpq) .*<(__interceptor_.*)?mem(cpy|set|move)>}}" %s
-
-int main() { return 0; }
diff --git a/compiler-rt/test/msan/Linux/check_memcpy.c b/compiler-rt/test/msan/Linux/check_memcpy.c
deleted file mode 100644
index 42af2d7..0000000
--- a/compiler-rt/test/msan/Linux/check_memcpy.c
+++ /dev/null
@@ -1,8 +0,0 @@
-// Verify runtime doesn't contain compiler-emitted memcpy/memmove calls.
-//
-// REQUIRES: shared_unwind, x86_64-target-arch
-
-// RUN: %clang_msan -O1 %s -o %t
-// RUN: llvm-objdump -d -l %t | FileCheck --implicit-check-not="{{(callq|jmpq) .*<(__interceptor_.*)?mem(cpy|set|move)>}}" %s
-
-int main() { return 0; }
diff --git a/compiler-rt/test/tsan/Linux/check_memcpy.c b/compiler-rt/test/tsan/Linux/check_memcpy.c
index 2148056..26f9961 100644
--- a/compiler-rt/test/tsan/Linux/check_memcpy.c
+++ b/compiler-rt/test/tsan/Linux/check_memcpy.c
@@ -5,9 +5,16 @@
 // This could fail if using a static libunwind because that static libunwind
 // could be uninstrumented and contain memcpy/memmove calls not intercepted by
 // tsan.
-// REQUIRES: shared_unwind, x86_64-target-arch
+// REQUIRES: shared_unwind
 
 // RUN: %clang_tsan -O1 %s -o %t
-// RUN: llvm-objdump -d -l %t | FileCheck --implicit-check-not="{{(callq|jmpq) .*<(__interceptor_.*)?mem(cpy|set|move)>}}" %s
+// RUN: llvm-objdump -d -l %t | FileCheck %s
 
-int main() { return 0; }
+int main() {
+  return 0;
+}
+
+// CHECK-NOT: callq {{.*<(__interceptor_)?mem(cpy|set)>}}
+// tail calls:
+// CHECK-NOT: jmpq {{.*<(__interceptor_)?mem(cpy|set)>}}
+
diff --git a/llvm/utils/gn/secondary/compiler-rt/lib/sanitizer_common/BUILD.gn b/llvm/utils/gn/secondary/compiler-rt/lib/sanitizer_common/BUILD.gn
index 174cbc5..03492849 100644
--- a/llvm/utils/gn/secondary/compiler-rt/lib/sanitizer_common/BUILD.gn
+++ b/llvm/utils/gn/secondary/compiler-rt/lib/sanitizer_common/BUILD.gn
@@ -113,7 +113,6 @@
     "sanitizer_procmaps_solaris.cpp",
     "sanitizer_ptrauth.h",
     "sanitizer_quarantine.h",
-    "sanitizer_redefine_builtins.h",
     "sanitizer_report_decorator.h",
     "sanitizer_ring_buffer.h",
     "sanitizer_solaris.cpp",