diff --git a/aom_ports/aom_ports.cmake b/aom_ports/aom_ports.cmake
index d579896..3ef1754 100644
--- a/aom_ports/aom_ports.cmake
+++ b/aom_ports/aom_ports.cmake
@@ -13,19 +13,12 @@
 endif() # AOM_AOM_PORTS_AOM_PORTS_CMAKE_
 set(AOM_AOM_PORTS_AOM_PORTS_CMAKE_ 1)
 
-list(APPEND AOM_PORTS_INCLUDES
-            "${AOM_ROOT}/aom_ports/aom_once.h"
-            "${AOM_ROOT}/aom_ports/aom_timer.h"
-            "${AOM_ROOT}/aom_ports/bitops.h"
+list(APPEND AOM_PORTS_INCLUDES "${AOM_ROOT}/aom_ports/aom_once.h"
+            "${AOM_ROOT}/aom_ports/aom_timer.h" "${AOM_ROOT}/aom_ports/bitops.h"
             "${AOM_ROOT}/aom_ports/emmintrin_compat.h"
-            "${AOM_ROOT}/aom_ports/mem.h"
-            "${AOM_ROOT}/aom_ports/mem_ops.h"
+            "${AOM_ROOT}/aom_ports/mem.h" "${AOM_ROOT}/aom_ports/mem_ops.h"
             "${AOM_ROOT}/aom_ports/mem_ops_aligned.h"
-            "${AOM_ROOT}/aom_ports/msvc.h"
-            "${AOM_ROOT}/aom_ports/sanitizer.h"
-            "${AOM_ROOT}/aom_ports/system_state.h")
-
-list(APPEND AOM_PORTS_ASM_X86 "${AOM_ROOT}/aom_ports/emms.asm")
+            "${AOM_ROOT}/aom_ports/msvc.h" "${AOM_ROOT}/aom_ports/sanitizer.h")
 
 list(APPEND AOM_PORTS_INCLUDES_X86 "${AOM_ROOT}/aom_ports/x86_abi_support.asm")
 
@@ -48,10 +41,7 @@
 #
 # * The libaom target must exist before this function is called.
 function(setup_aom_ports_targets)
-  if("${AOM_TARGET_CPU}" MATCHES "^x86")
-    add_asm_library("aom_ports" "AOM_PORTS_ASM_X86")
-    set(aom_ports_has_symbols 1)
-  elseif("${AOM_TARGET_CPU}" MATCHES "arm")
+  if("${AOM_TARGET_CPU}" MATCHES "arm")
     add_library(aom_ports OBJECT ${AOM_PORTS_SOURCES_ARM})
     set(aom_ports_has_symbols 1)
   elseif("${AOM_TARGET_CPU}" MATCHES "ppc")
@@ -69,11 +59,6 @@
   if(aom_ports_has_symbols)
     target_sources(aom_ports PRIVATE ${AOM_PORTS_INCLUDES})
 
-    if("${AOM_TARGET_CPU}" STREQUAL "x86"
-       OR "${AOM_TARGET_CPU}" STREQUAL "x86_64")
-      target_sources(aom_ports PRIVATE ${AOM_PORTS_INCLUDES_X86})
-    endif()
-
     set(AOM_LIB_TARGETS ${AOM_LIB_TARGETS} PARENT_SCOPE)
   else()
     target_sources(aom PRIVATE ${AOM_PORTS_INCLUDES})
diff --git a/aom_ports/emms.asm b/aom_ports/emms.asm
deleted file mode 100644
index 038635d..0000000
--- a/aom_ports/emms.asm
+++ /dev/null
@@ -1,41 +0,0 @@
-;
-; Copyright (c) 2016, Alliance for Open Media. All rights reserved
-;
-; This source code is subject to the terms of the BSD 2 Clause License and
-; the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
-; was not distributed with this source code in the LICENSE file, you can
-; obtain it at www.aomedia.org/license/software. If the Alliance for Open
-; Media Patent License 1.0 was not distributed with this source code in the
-; PATENTS file, you can obtain it at www.aomedia.org/license/patent.
-;
-
-;
-
-
-%include "aom_ports/x86_abi_support.asm"
-
-section .text
-globalsym(aom_reset_mmx_state)
-sym(aom_reset_mmx_state):
-    emms
-    ret
-
-
-%if LIBAOM_YASM_WIN64
-globalsym(aom_winx64_fldcw)
-sym(aom_winx64_fldcw):
-    sub   rsp, 8
-    mov   [rsp], rcx ; win x64 specific
-    fldcw [rsp]
-    add   rsp, 8
-    ret
-
-
-globalsym(aom_winx64_fstcw)
-sym(aom_winx64_fstcw):
-    sub   rsp, 8
-    fstcw [rsp]
-    mov   rax, [rsp]
-    add   rsp, 8
-    ret
-%endif
diff --git a/aom_ports/system_state.h b/aom_ports/system_state.h
deleted file mode 100644
index 8a8682d..0000000
--- a/aom_ports/system_state.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright (c) 2016, Alliance for Open Media. All rights reserved
- *
- * This source code is subject to the terms of the BSD 2 Clause License and
- * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
- * was not distributed with this source code in the LICENSE file, you can
- * obtain it at www.aomedia.org/license/software. If the Alliance for Open
- * Media Patent License 1.0 was not distributed with this source code in the
- * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
- */
-
-#ifndef AOM_AOM_PORTS_SYSTEM_STATE_H_
-#define AOM_AOM_PORTS_SYSTEM_STATE_H_
-
-#include "config/aom_config.h"
-
-#if ARCH_X86 || ARCH_X86_64
-void aom_reset_mmx_state(void);
-#else
-#endif  // ARCH_X86 || ARCH_X86_64
-#endif  // AOM_AOM_PORTS_SYSTEM_STATE_H_