diff --git a/libc/src/string/CMakeLists.txt b/libc/src/string/CMakeLists.txt
--- a/libc/src/string/CMakeLists.txt
+++ b/libc/src/string/CMakeLists.txt
@@ -279,7 +279,6 @@
     ${ARGN})
 
   if("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
-    list(APPEND ADD_IMPL_MLLVM_COMPILE_OPTIONS "-combiner-global-alias-analysis")
     # Note that '-mllvm' needs to be prefixed with 'SHELL:' to prevent CMake flag deduplication.
     foreach(opt IN LISTS ADD_IMPL_MLLVM_COMPILE_OPTIONS)
       list(APPEND ADD_IMPL_COMPILE_OPTIONS "SHELL:-mllvm ${opt}")
diff --git a/libc/src/string/memory_utils/memcpy_implementations.h b/libc/src/string/memory_utils/memcpy_implementations.h
--- a/libc/src/string/memory_utils/memcpy_implementations.h
+++ b/libc/src/string/memory_utils/memcpy_implementations.h
@@ -39,11 +39,11 @@
 
 static inline void inline_memcpy(char *__restrict dst,
                                  const char *__restrict src, size_t count) {
+  using namespace __llvm_libc::builtin;
 #if defined(LLVM_LIBC_ARCH_X86)
   /////////////////////////////////////////////////////////////////////////////
   // LLVM_LIBC_ARCH_X86
   /////////////////////////////////////////////////////////////////////////////
-  using namespace __llvm_libc::x86;
 
   // Whether to use only rep;movsb.
   constexpr bool USE_ONLY_REP_MOVSB =
@@ -69,7 +69,7 @@
 #endif
 
   if (USE_ONLY_REP_MOVSB)
-    return copy<Accelerator>(dst, src, count);
+    return copy<x86::Accelerator>(dst, src, count);
 
   if (count == 0)
     return;
@@ -96,12 +96,11 @@
   if (count <= REP_MOVS_B_SIZE)
     return copy<Align<_32, Arg::Dst>::Then<Loop<LoopBlockSize>>>(dst, src,
                                                                  count);
-  return copy<Accelerator>(dst, src, count);
+  return copy<x86::Accelerator>(dst, src, count);
 #elif defined(LLVM_LIBC_ARCH_AARCH64)
   /////////////////////////////////////////////////////////////////////////////
   // LLVM_LIBC_ARCH_AARCH64
   /////////////////////////////////////////////////////////////////////////////
-  using namespace __llvm_libc::scalar;
   if (count == 0)
     return;
   if (count == 1)
@@ -127,7 +126,6 @@
   /////////////////////////////////////////////////////////////////////////////
   // Default
   /////////////////////////////////////////////////////////////////////////////
-  using namespace __llvm_libc::scalar;
   if (count == 0)
     return;
   if (count == 1)
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -829,7 +829,6 @@
     copts = [
         "-fno-builtin-memcpy",
         "-fno-builtin-memmove",
-        "-mllvm -combiner-global-alias-analysis",
         "-mllvm --tail-merge-threshold=0",
     ],
     features = no_sanitize_features,
@@ -845,7 +844,6 @@
     hdrs = ["src/string/memset.h"],
     copts = [
         "-fno-builtin-memset",
-        "-mllvm -combiner-global-alias-analysis",
     ],
     features = no_sanitize_features,
     deps = [
@@ -860,7 +858,6 @@
     hdrs = ["src/string/memmove.h"],
     copts = [
         "-fno-builtin-memmove",
-        "-mllvm -combiner-global-alias-analysis",
     ],
     features = no_sanitize_features,
     deps = [
@@ -876,7 +873,6 @@
     hdrs = ["src/string/memcmp.h"],
     copts = [
         "-fno-builtin-memcmp",
-        "-mllvm -combiner-global-alias-analysis",
     ],
     features = no_sanitize_features,
     deps = [
@@ -908,7 +904,6 @@
     copts = [
         "-fno-builtin-bzero",
         "-fno-builtin-memset",
-        "-mllvm -combiner-global-alias-analysis",
     ],
     features = no_sanitize_features,
     deps = [