Update libaom to commit ID 1e227d41f0616de9548a673a83a21ef990b62591

14 files changed, 349 insertions, 199 deletions

diff --git a/third_party/aom/build/cmake/aom_config_defaults.cmake b/third_party/aom/build/cmake/aom_config_defaults.cmake
index 19af5c43b8..a07438cfe3 100644
--- a/third_party/aom/build/cmake/aom_config_defaults.cmake
+++ b/third_party/aom/build/cmake/aom_config_defaults.cmake
@@ -7,90 +7,190 @@
 # 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_ROOT}/build/cmake/util.cmake")
+
+# This file sets default values for libaom configuration variables. All libaom
+# config variables are added to the CMake variable cache via the macros provided
+# in util.cmake.
+
 #
-# Defaults for every libaom configuration variable. Here we add all libaom
-# config variables to the cmake variable cache, but omit the FORCE parameter to
-# allow users to specify values when executing cmake to generate build files.
-# Values here are used only if not set by the user.
-set(INLINE "" CACHE STRING "Sets INLINE value for current target.")
+# The variables in this section of the file are detected at configuration time,
+# but can be overridden via the use of CONFIG_* and ENABLE_* values also defined
+# in this file.
+#
+
+set_aom_detect_var(INLINE "" STRING "Sets INLINE value for current target.")
 
 # CPUs.
-set(ARCH_ARM 0 CACHE NUMBER "Enables ARM architecture.")
-set(ARCH_MIPS 0 CACHE NUMBER "Enables MIPS architecture.")
-set(ARCH_PPC 0 CACHE NUMBER "Enables PPC architecture.")
-set(ARCH_X86 0 CACHE NUMBER "Enables X86 architecture.")
-set(ARCH_X86_64 0 CACHE NUMBER "Enables X86_64 architecture.")
-
-# ARM optimization flags.
-set(HAVE_NEON 0 CACHE NUMBER "Enables NEON intrinsics optimizations.")
-
-# MIPS optimization flags.
-set(HAVE_DSPR2 0 CACHE NUMBER "Enables DSPR2 optimizations.")
-set(HAVE_MIPS32 0 CACHE NUMBER "Enables MIPS32 optimizations.")
-set(HAVE_MIPS64 0 CACHE NUMBER "Enables MIPS64 optimizations. ")
-set(HAVE_MSA 0 CACHE NUMBER "Enables MSA optimizations.")
-
-# PPC optimization flags.
-set(HAVE_VSX 0 CACHE NUMBER "Enables VSX optimizations.")
-
-# x86/x86_64 optimization flags.
-set(HAVE_AVX 0 CACHE NUMBER "Enables AVX optimizations.")
-set(HAVE_AVX2 0 CACHE NUMBER "Enables AVX2 optimizations.")
-set(HAVE_MMX 0 CACHE NUMBER "Enables MMX optimizations. ")
-set(HAVE_SSE 0 CACHE NUMBER "Enables SSE optimizations.")
-set(HAVE_SSE2 0 CACHE NUMBER "Enables SSE2 optimizations.")
-set(HAVE_SSE3 0 CACHE NUMBER "Enables SSE3 optimizations.")
-set(HAVE_SSE4_1 0 CACHE NUMBER "Enables SSE 4.1 optimizations.")
-set(HAVE_SSE4_2 0 CACHE NUMBER "Enables SSE 4.2 optimizations.")
-set(HAVE_SSSE3 0 CACHE NUMBER "Enables SSSE3 optimizations.")
+set_aom_detect_var(ARCH_ARM 0 NUMBER "Enables ARM architecture.")
+set_aom_detect_var(ARCH_MIPS 0 NUMBER "Enables MIPS architecture.")
+set_aom_detect_var(ARCH_PPC 0 NUMBER "Enables PPC architecture.")
+set_aom_detect_var(ARCH_X86 0 NUMBER "Enables X86 architecture.")
+set_aom_detect_var(ARCH_X86_64 0 NUMBER "Enables X86_64 architecture.")
+
+# ARM feature flags.
+set_aom_detect_var(HAVE_NEON 0 NUMBER "Enables NEON intrinsics optimizations.")
+
+# MIPS feature flags.
+set_aom_detect_var(HAVE_DSPR2 0 NUMBER "Enables DSPR2 optimizations.")
+set_aom_detect_var(HAVE_MIPS32 0 NUMBER "Enables MIPS32 optimizations.")
+set_aom_detect_var(HAVE_MIPS64 0 NUMBER "Enables MIPS64 optimizations. ")
+set_aom_detect_var(HAVE_MSA 0 NUMBER "Enables MSA optimizations.")
+
+# PPC feature flags.
+set_aom_detect_var(HAVE_VSX 0 NUMBER "Enables VSX optimizations.")
+
+# x86/x86_64 feature flags.
+set_aom_detect_var(HAVE_AVX 0 NUMBER "Enables AVX optimizations.")
+set_aom_detect_var(HAVE_AVX2 0 NUMBER "Enables AVX2 optimizations.")
+set_aom_detect_var(HAVE_MMX 0 NUMBER "Enables MMX optimizations. ")
+set_aom_detect_var(HAVE_SSE 0 NUMBER "Enables SSE optimizations.")
+set_aom_detect_var(HAVE_SSE2 0 NUMBER "Enables SSE2 optimizations.")
+set_aom_detect_var(HAVE_SSE3 0 NUMBER "Enables SSE3 optimizations.")
+set_aom_detect_var(HAVE_SSE4_1 0 NUMBER "Enables SSE 4.1 optimizations.")
+set_aom_detect_var(HAVE_SSE4_2 0 NUMBER "Enables SSE 4.2 optimizations.")
+set_aom_detect_var(HAVE_SSSE3 0 NUMBER "Enables SSSE3 optimizations.")
 
 # Flags describing the build environment.
-set(HAVE_FEXCEPT 0 CACHE NUMBER "Internal flag, GNU fenv.h present for target.")
-set(HAVE_PTHREAD_H 0 CACHE NUMBER "Internal flag, target pthread support.")
-set(HAVE_UNISTD_H 0 CACHE NUMBER "Internal flag, unistd.h present for target.")
-set(HAVE_WXWIDGETS 0 CACHE NUMBER "WxWidgets present.")
+set_aom_detect_var(HAVE_FEXCEPT 0 NUMBER
+                   "Internal flag, GNU fenv.h present for target.")
+set_aom_detect_var(HAVE_PTHREAD_H 0 NUMBER
+                   "Internal flag, target pthread support.")
+set_aom_detect_var(HAVE_UNISTD_H 0 NUMBER
+                   "Internal flag, unistd.h present for target.")
+set_aom_detect_var(HAVE_WXWIDGETS 0 NUMBER "WxWidgets present.")
+
+#
+# Variables in this section can be set from the CMake command line or from
+# within the CMake GUI. The variables control libaom features.
+#
 
 # Build configuration flags.
-set(CONFIG_AV1_DECODER 1 CACHE NUMBER "Enable AV1 decoder.")
-set(CONFIG_AV1_ENCODER 1 CACHE NUMBER "Enable AV1 encoder.")
-set(CONFIG_BIG_ENDIAN 0 CACHE NUMBER "Internal flag.")
-set(CONFIG_GCC 0 CACHE NUMBER "Building with GCC (detected).")
-set(CONFIG_GCOV 0 CACHE NUMBER "Enable gcov support.")
-set(CONFIG_GPROF 0 CACHE NUMBER "Enable gprof support.")
-set(CONFIG_LIBYUV 1 CACHE NUMBER "Enables libyuv scaling/conversion support.")
-set(CONFIG_MSVS 0 CACHE NUMBER "Building with MS Visual Studio (detected).")
-set(CONFIG_MULTITHREAD 1 CACHE NUMBER "Multithread support.")
-set(CONFIG_OS_SUPPORT 0 CACHE NUMBER "Internal flag.")
-set(CONFIG_PIC 0 CACHE NUMBER "Build with PIC enabled.")
-set(CONFIG_RUNTIME_CPU_DETECT 1 CACHE NUMBER "Runtime CPU detection support.")
-set(CONFIG_SHARED 0 CACHE NUMBER "Build shared libs.")
-set(CONFIG_STATIC 1 CACHE NUMBER "Build static libs.")
-set(CONFIG_WEBM_IO 1 CACHE NUMBER "Enables WebM support.")
+set_aom_config_var(AOM_RTCD_FLAGS "" STRING
+                   "Arguments to pass to rtcd.pl. Separate with ';'")
+set_aom_config_var(CONFIG_AV1_DECODER 1 NUMBER "Enable AV1 decoder.")
+set_aom_config_var(CONFIG_AV1_ENCODER 1 NUMBER "Enable AV1 encoder.")
+set_aom_config_var(CONFIG_BIG_ENDIAN 0 NUMBER "Internal flag.")
+set_aom_config_var(CONFIG_GCC 0 NUMBER "Building with GCC (detect).")
+set_aom_config_var(CONFIG_GCOV 0 NUMBER "Enable gcov support.")
+set_aom_config_var(CONFIG_GPROF 0 NUMBER "Enable gprof support.")
+set_aom_config_var(CONFIG_LIBYUV 1 NUMBER
+                   "Enables libyuv scaling/conversion support.")
+
+set_aom_config_var(CONFIG_MULTITHREAD 1 NUMBER "Multithread support.")
+set_aom_config_var(CONFIG_OS_SUPPORT 0 NUMBER "Internal flag.")
+set_aom_config_var(CONFIG_PIC 0 NUMBER "Build with PIC enabled.")
+set_aom_config_var(CONFIG_RUNTIME_CPU_DETECT 1 NUMBER
+                   "Runtime CPU detection support.")
+set_aom_config_var(CONFIG_SHARED 0 NUMBER "Build shared libs.")
+set_aom_config_var(CONFIG_STATIC 1 NUMBER "Build static libs.")
+set_aom_config_var(CONFIG_WEBM_IO 1 NUMBER "Enables WebM support.")
 
 # Debugging flags.
-set(CONFIG_BITSTREAM_DEBUG 0 CACHE NUMBER "Bitstream debugging flag.")
-set(CONFIG_DEBUG 0 CACHE NUMBER "Debug build flag.")
-set(CONFIG_MISMATCH_DEBUG 0 CACHE NUMBER "Mismatch debugging flag.")
+set_aom_config_var(CONFIG_BITSTREAM_DEBUG 0 NUMBER "Bitstream debugging flag.")
+set_aom_config_var(CONFIG_DEBUG 0 NUMBER "Debug build flag.")
+set_aom_config_var(CONFIG_MISMATCH_DEBUG 0 NUMBER "Mismatch debugging flag.")
 
 # AV1 feature flags.
-set(CONFIG_ACCOUNTING 0 CACHE NUMBER "Enables bit accounting.")
-set(CONFIG_ANALYZER 0 CACHE NUMBER "Enables bit stream analyzer.")
-set(CONFIG_COEFFICIENT_RANGE_CHECKING 0 CACHE NUMBER "Coefficient range check.")
-set(CONFIG_DENOISE 0 CACHE NUMBER "Denoise/noise modeling support in encoder.")
-set(CONFIG_FILEOPTIONS 1 CACHE NUMBER "Enables encoder config file support.")
-set(CONFIG_INSPECTION 0 CACHE NUMBER "Enables bitstream inspection.")
-set(CONFIG_INTERNAL_STATS 0 CACHE NUMBER "Enables internal encoder stats.")
-set(CONFIG_LOWBITDEPTH 0 CACHE NUMBER "Enables 8-bit optimized pipeline.")
-set(CONFIG_SIZE_LIMIT 0 CACHE NUMBER "Limit max decode width/height.")
-set(CONFIG_SPATIAL_RESAMPLING 1 CACHE NUMBER "Spatial resampling.")
-set(DECODE_HEIGHT_LIMIT 0 CACHE NUMBER "Set limit for decode height.")
-set(DECODE_WIDTH_LIMIT 0 CACHE NUMBER "Set limit for decode width.")
+set_aom_config_var(CONFIG_ACCOUNTING 0 NUMBER "Enables bit accounting.")
+set_aom_config_var(CONFIG_ANALYZER 0 NUMBER "Enables bit stream analyzer.")
+set_aom_config_var(CONFIG_COEFFICIENT_RANGE_CHECKING 0 NUMBER
+                   "Coefficient range check.")
+set_aom_config_var(CONFIG_DENOISE 1 NUMBER
+                   "Denoise/noise modeling support in encoder.")
+set_aom_config_var(CONFIG_FILEOPTIONS 1 NUMBER
+                   "Enables encoder config file support.")
+set_aom_config_var(CONFIG_FIX_GF_LENGTH 1 NUMBER
+                   "Fix the GF length if possible")
+set_aom_config_var(CONFIG_INSPECTION 0 NUMBER "Enables bitstream inspection.")
+set_aom_config_var(CONFIG_INTERNAL_STATS 0 NUMBER
+                   "Enables internal encoder stats.")
+set_aom_config_var(CONFIG_LOWBITDEPTH 0 NUMBER
+                   "Enables 8-bit optimized pipeline.")
+set_aom_config_var(CONFIG_MAX_DECODE_PROFILE 2 NUMBER
+                   "Max profile to support decoding.")
+set_aom_config_var(CONFIG_NORMAL_TILE_MODE 0 NUMBER
+                   "Only enables normal tile mode.")
+set_aom_config_var(
+  CONFIG_REDUCED_ENCODER_BORDER 0 NUMBER
+  "Enable reduced border extention for encoder. \
+                    Disables superres and resize support."
+  )
+set_aom_config_var(CONFIG_SIZE_LIMIT 0 NUMBER "Limit max decode width/height.")
+set_aom_config_var(CONFIG_SPATIAL_RESAMPLING 1 NUMBER "Spatial resampling.")
+set_aom_config_var(DECODE_HEIGHT_LIMIT 0 NUMBER "Set limit for decode height.")
+set_aom_config_var(DECODE_WIDTH_LIMIT 0 NUMBER "Set limit for decode width.")
+set_aom_config_var(CONFIG_GLOBAL_MOTION_SEARCH 1 NUMBER
+                   "Global motion search flag.")
 
 # AV1 experiment flags.
-set(CONFIG_COLLECT_INTER_MODE_RD_STATS 1 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_COLLECT_RD_STATS 0 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_DIST_8X8 1 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_ENTROPY_STATS 0 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_FP_MB_STATS 0 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_INTER_STATS_ONLY 0 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_RD_DEBUG 0 CACHE NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_COLLECT_INTER_MODE_RD_STATS 1 NUMBER
+                   "AV1 experiment flag.")
+set_aom_config_var(CONFIG_COLLECT_RD_STATS 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_DIST_8X8 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_ENTROPY_STATS 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_FP_MB_STATS 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_INTER_STATS_ONLY 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_RD_DEBUG 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_2PASS_PARTITION_SEARCH_LVL 1 NUMBER
+                   "AV1 experiment flag.")
+set_aom_config_var(CONFIG_SHARP_SETTINGS 0 NUMBER
+                   "Use sharper encoding settings")
+
+#
+# Variables in this section control optional features of the build system.
+#
+set_aom_option_var(ENABLE_CCACHE "Enable ccache support." OFF)
+set_aom_option_var(ENABLE_DECODE_PERF_TESTS "Enables decoder performance tests"
+                   OFF)
+set_aom_option_var(ENABLE_DISTCC "Enable distcc support." OFF)
+set_aom_option_var(ENABLE_DOCS
+                   "Enable documentation generation (doxygen required)." ON)
+set_aom_option_var(ENABLE_ENCODE_PERF_TESTS "Enables encoder performance tests"
+                   OFF)
+set_aom_option_var(ENABLE_EXAMPLES "Enables build of example code." ON)
+set_aom_option_var(ENABLE_GOMA "Enable goma support." OFF)
+set_aom_option_var(
+  ENABLE_IDE_TEST_HOSTING
+  "Enables running tests within IDEs like Visual Studio and Xcode." OFF)
+set_aom_option_var(ENABLE_NASM "Use nasm instead of yasm for x86 assembly." OFF)
+set_aom_option_var(ENABLE_TESTDATA "Enables unit test data download targets."
+                   ON)
+set_aom_option_var(ENABLE_TESTS "Enables unit tests." ON)
+set_aom_option_var(ENABLE_TOOLS "Enable applications in tools sub directory."
+                   ON)
+set_aom_option_var(ENABLE_WERROR "Converts warnings to errors at compile time."
+                   OFF)
+
+# ARM assembly/intrinsics flags.
+set_aom_option_var(ENABLE_NEON "Enables NEON optimizations on ARM targets." ON)
+
+# MIPS assembly/intrinsics flags.
+set_aom_option_var(ENABLE_DSPR2 "Enables DSPR2 optimizations on MIPS targets."
+                   OFF)
+set_aom_option_var(ENABLE_MSA "Enables MSA optimizations on MIPS targets." OFF)
+
+# VSX intrinsics flags.
+set_aom_option_var(ENABLE_VSX "Enables VSX optimizations on PowerPC targets."
+                   ON)
+
+# x86/x86_64 assembly/intrinsics flags.
+set_aom_option_var(ENABLE_MMX
+                   "Enables MMX optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSE
+                   "Enables SSE optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSE2
+                   "Enables SSE2 optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSE3
+                   "Enables SSE3 optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSSE3
+                   "Enables SSSE3 optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSE4_1
+                   "Enables SSE4_1 optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSE4_2
+                   "Enables SSE4_2 optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_AVX
+                   "Enables AVX optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_AVX2
+                   "Enables AVX2 optimizations on x86/x86_64 targets." ON)
diff --git a/third_party/aom/build/cmake/aom_configure.cmake b/third_party/aom/build/cmake/aom_configure.cmake
index a123897789..c0c7381e87 100644
--- a/third_party/aom/build/cmake/aom_configure.cmake
+++ b/third_party/aom/build/cmake/aom_configure.cmake
@@ -20,19 +20,6 @@ include(FindThreads)
 set(AOM_SUPPORTED_CPU_TARGETS
     "arm64 armv7 armv7s generic mips32 mips64 ppc x86 x86_64")
 
-# Generate the user config settings. This must occur before include of
-# aom_config_defaults.cmake (because it turns every config variable into a cache
-# variable with its own help string).
-get_cmake_property(cmake_cache_vars CACHE_VARIABLES)
-foreach(cache_var ${cmake_cache_vars})
-  get_property(cache_var_helpstring CACHE ${cache_var} PROPERTY HELPSTRING)
-  set(cmdline_helpstring "No help, variable specified on the command line.")
-  if("${cache_var_helpstring}" STREQUAL "${cmdline_helpstring}")
-    set(AOM_CMAKE_CONFIG "${AOM_CMAKE_CONFIG} -D${cache_var}=${${cache_var}}")
-  endif()
-endforeach()
-string(STRIP "${AOM_CMAKE_CONFIG}" AOM_CMAKE_CONFIG)
-
 include("${AOM_ROOT}/build/cmake/aom_config_defaults.cmake")
 include("${AOM_ROOT}/build/cmake/aom_experiment_deps.cmake")
 include("${AOM_ROOT}/build/cmake/aom_optimization.cmake")
@@ -40,6 +27,16 @@ include("${AOM_ROOT}/build/cmake/compiler_flags.cmake")
 include("${AOM_ROOT}/build/cmake/compiler_tests.cmake")
 include("${AOM_ROOT}/build/cmake/util.cmake")
 
+# Generate the user config settings.
+list(APPEND aom_build_vars ${AOM_CONFIG_VARS} ${AOM_OPTION_VARS})
+foreach(cache_var ${aom_build_vars})
+  get_property(cache_var_helpstring CACHE ${cache_var} PROPERTY HELPSTRING)
+  if("${cache_var_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    set(AOM_CMAKE_CONFIG "${AOM_CMAKE_CONFIG} -D${cache_var}=${${cache_var}}")
+  endif()
+endforeach()
+string(STRIP "${AOM_CMAKE_CONFIG}" AOM_CMAKE_CONFIG)
+
 # Detect target CPU.
 if(NOT AOM_TARGET_CPU)
   if("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "AMD64" OR
@@ -73,7 +70,9 @@ if(NOT AOM_TARGET_CPU)
 endif()
 
 if(CMAKE_TOOLCHAIN_FILE) # Add toolchain file to config string.
-  set(toolchain_string "-DCMAKE_TOOLCHAIN_FILE=\\\"${CMAKE_TOOLCHAIN_FILE}\\\"")
+  file(RELATIVE_PATH toolchain_path "${AOM_CONFIG_DIR}"
+                     "${CMAKE_TOOLCHAIN_FILE}")
+  set(toolchain_string "-DCMAKE_TOOLCHAIN_FILE=\\\"${toolchain_path}\\\"")
   set(AOM_CMAKE_CONFIG "${toolchain_string} ${AOM_CMAKE_CONFIG}")
 else()
 
@@ -81,6 +80,8 @@ else()
   set(AOM_CMAKE_CONFIG "-DAOM_TARGET_CPU=${AOM_TARGET_CPU} ${AOM_CMAKE_CONFIG}")
 endif()
 set(AOM_CMAKE_CONFIG "-G \\\"${CMAKE_GENERATOR}\\\" ${AOM_CMAKE_CONFIG}")
+file(RELATIVE_PATH source_path "${AOM_CONFIG_DIR}" "${AOM_ROOT}")
+set(AOM_CMAKE_CONFIG "cmake ${source_path} ${AOM_CMAKE_CONFIG}")
 string(STRIP "${AOM_CMAKE_CONFIG}" AOM_CMAKE_CONFIG)
 
 message("--- aom_configure: Detected CPU: ${AOM_TARGET_CPU}")
@@ -90,13 +91,13 @@ if("${CMAKE_BUILD_TYPE}" MATCHES "Deb")
   set(CONFIG_DEBUG 1)
 endif()
 
-if(NOT MSVC)
-  if(BUILD_SHARED_LIBS)
-    set(CONFIG_PIC 1)
-    set(CONFIG_SHARED 1)
-    set(CONFIG_STATIC 0)
-  endif()
+if(BUILD_SHARED_LIBS)
+  set(CONFIG_PIC 1)
+  set(CONFIG_SHARED 1)
+  set(CONFIG_STATIC 0)
+endif()
 
+if(NOT MSVC)
   if(CONFIG_PIC)
 
     # TODO(tomfinegan): clang needs -pie in CMAKE_EXE_LINKER_FLAGS for this to
@@ -109,8 +110,6 @@ if(NOT MSVC)
       set(AOM_AS_FLAGS ${AOM_AS_FLAGS} -DPIC)
     endif()
   endif()
-else()
-  set(CONFIG_MSVS 1)
 endif()
 
 if(NOT "${AOM_SUPPORTED_CPU_TARGETS}" MATCHES "${AOM_TARGET_CPU}")
@@ -261,13 +260,15 @@ else()
   add_compiler_flag_if_supported("-Wlogical-op")
   add_compiler_flag_if_supported("-Wpointer-arith")
   add_compiler_flag_if_supported("-Wsign-compare")
-  add_compiler_flag_if_supported("-Wstack-usage=360000")
   add_compiler_flag_if_supported("-Wstring-conversion")
   add_compiler_flag_if_supported("-Wtype-limits")
   add_compiler_flag_if_supported("-Wuninitialized")
   add_compiler_flag_if_supported("-Wunused")
   add_compiler_flag_if_supported("-Wvla")
 
+  add_c_flag_if_supported("-Wstack-usage=100000")
+  add_cxx_flag_if_supported("-Wstack-usage=360000")
+
   # TODO(jzern): this could be added as a cxx flags for test/*.cc only, avoiding
   # third_party.
   add_c_flag_if_supported("-Wshorten-64-to-32")
@@ -278,6 +279,12 @@ else()
   # Add -Wundef only for C files to avoid massive gtest warning spam.
   add_c_flag_if_supported("-Wundef")
 
+  # Quiet gcc 6 vs 7 abi warnings:
+  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77728
+  if("${AOM_TARGET_CPU}" MATCHES "arm")
+    add_cxx_flag_if_supported("-Wno-psabi")
+  endif()
+
   if(ENABLE_WERROR)
     add_compiler_flag_if_supported("-Werror")
   endif()
@@ -344,7 +351,7 @@ foreach(NUM RANGE ${AOM_RTCD_CUSTOM_COMMAND_COUNT})
   list(GET AOM_RTCD_HEADER_FILE_LIST ${NUM} AOM_RTCD_HEADER_FILE)
   list(GET AOM_RTCD_SOURCE_FILE_LIST ${NUM} AOM_RTCD_SOURCE_FILE)
   list(GET AOM_RTCD_SYMBOL_LIST ${NUM} AOM_RTCD_SYMBOL)
-  execute_process(COMMAND ${PERL_EXECUTABLE} "${AOM_ROOT}/build/make/rtcd.pl"
+  execute_process(COMMAND ${PERL_EXECUTABLE} "${AOM_ROOT}/build/cmake/rtcd.pl"
                           --arch=${AOM_TARGET_CPU}
                           --sym=${AOM_RTCD_SYMBOL} ${AOM_RTCD_FLAGS}
                           --config=${AOM_CONFIG_DIR}/config/aom_config.h
diff --git a/third_party/aom/build/cmake/aom_experiment_deps.cmake b/third_party/aom/build/cmake/aom_experiment_deps.cmake
index e2c8102aa4..0688704e5f 100644
--- a/third_party/aom/build/cmake/aom_experiment_deps.cmake
+++ b/third_party/aom/build/cmake/aom_experiment_deps.cmake
@@ -25,4 +25,8 @@ macro(fix_experiment_configs)
     change_config_and_warn(CONFIG_RD_DEBUG 0 CONFIG_JNT_COMP)
   endif()
 
+  if(CONFIG_DIST_8X8 AND CONFIG_MULTITHREAD)
+    change_config_and_warn(CONFIG_DIST_8X8 0 CONFIG_MULTITHREAD)
+  endif()
+
 endmacro()
diff --git a/third_party/aom/build/cmake/aom_optimization.cmake b/third_party/aom/build/cmake/aom_optimization.cmake
index ce3dc0340f..be32a32126 100644
--- a/third_party/aom/build/cmake/aom_optimization.cmake
+++ b/third_party/aom/build/cmake/aom_optimization.cmake
@@ -193,13 +193,13 @@ function(test_nasm)
 endfunction()
 
 # Adds build command for generation of rtcd C source files using
-# build/make/rtcd.pl. $config is the input perl file, $output is the output C
+# build/cmake/rtcd.pl. $config is the input perl file, $output is the output C
 # include file, $source is the C source file, and $symbol is used for the symbol
 # argument passed to rtcd.pl.
 function(add_rtcd_build_step config output source symbol)
   add_custom_command(OUTPUT ${output}
                      COMMAND ${PERL_EXECUTABLE} ARGS
-                             "${AOM_ROOT}/build/make/rtcd.pl"
+                             "${AOM_ROOT}/build/cmake/rtcd.pl"
                              --arch=${AOM_TARGET_CPU}
                              --sym=${symbol} ${AOM_RTCD_FLAGS}
                              --config=${AOM_CONFIG_DIR}/config/aom_config.h
diff --git a/third_party/aom/build/cmake/exports.cmake b/third_party/aom/build/cmake/exports.cmake
index 5abfc9a5f7..e0813dc0f2 100644
--- a/third_party/aom/build/cmake/exports.cmake
+++ b/third_party/aom/build/cmake/exports.cmake
@@ -34,7 +34,8 @@ function(setup_exports_target)
                             -DAOM_SYM_FILE="${aom_sym_file}" -DAOM_MSVC=${MSVC}
                             -DAOM_XCODE=${XCODE} -DCONFIG_NAME=$<CONFIG>
                             -DCONFIG_AV1_DECODER=${CONFIG_AV1_DECODER}
-                            -DCONFIG_AV1_ENCODER=${CONFIG_AV1_ENCODER} -P
+                            -DCONFIG_AV1_ENCODER=${CONFIG_AV1_ENCODER}
+                            -DENABLE_TESTS=${ENABLE_TESTS} -P
                             "${AOM_ROOT}/build/cmake/generate_exports.cmake"
                     SOURCES ${AOM_EXPORTS_SOURCES}
                     DEPENDS ${AOM_EXPORTS_SOURCES})
@@ -47,10 +48,12 @@ function(setup_exports_target)
     set_property(TARGET aom APPEND_STRING
                  PROPERTY LINK_FLAGS "-exported_symbols_list ${aom_sym_file}")
   elseif(WIN32)
-    message(FATAL_ERROR "Windows DLL builds not supported yet.")
     if(NOT MSVC)
       set_property(TARGET aom APPEND_STRING
                    PROPERTY LINK_FLAGS "-Wl,--version-script ${aom_sym_file}")
+    else()
+      set_property(TARGET aom APPEND_STRING
+                   PROPERTY LINK_FLAGS "/DEF:${aom_sym_file}")
     endif()
 
     # TODO(tomfinegan): Sort out the import lib situation and flags for MSVC.
diff --git a/third_party/aom/build/cmake/exports_sources.cmake b/third_party/aom/build/cmake/exports_sources.cmake
index 48790dbaa1..576920e36c 100644
--- a/third_party/aom/build/cmake/exports_sources.cmake
+++ b/third_party/aom/build/cmake/exports_sources.cmake
@@ -13,14 +13,20 @@ if(AOM_BUILD_CMAKE_EXPORTS_SOURCES_CMAKE_)
 endif() # AOM_BUILD_CMAKE_EXPORTS_SOURCES_CMAKE_
 set(AOM_BUILD_CMAKE_EXPORTS_SOURCES_CMAKE_ 1)
 
-set(AOM_EXPORTS_SOURCES "${AOM_ROOT}/aom/exports_com")
+list(APPEND AOM_EXPORTS_SOURCES "${AOM_ROOT}/aom/exports_com"
+            "${AOM_ROOT}/av1/exports_com")
 
 if(CONFIG_AV1_DECODER)
-  set(AOM_EXPORTS_SOURCES ${AOM_EXPORTS_SOURCES} "${AOM_ROOT}/aom/exports_dec"
-      "${AOM_ROOT}/av1/exports_dec")
+  list(APPEND AOM_EXPORTS_SOURCES "${AOM_ROOT}/aom/exports_dec"
+              "${AOM_ROOT}/av1/exports_dec")
 endif()
 
 if(CONFIG_AV1_ENCODER)
-  set(AOM_EXPORTS_SOURCES ${AOM_EXPORTS_SOURCES} "${AOM_ROOT}/aom/exports_enc"
-      "${AOM_ROOT}/av1/exports_enc")
+  list(APPEND AOM_EXPORTS_SOURCES "${AOM_ROOT}/aom/exports_enc"
+              "${AOM_ROOT}/av1/exports_enc")
+endif()
+
+if(ENABLE_TESTS)
+  list(APPEND AOM_EXPORTS_SOURCES "${AOM_ROOT}/aom/exports_test"
+              "${AOM_ROOT}/av1/exports_test")
 endif()
diff --git a/third_party/aom/build/cmake/generate_aom_config_templates.cmake b/third_party/aom/build/cmake/generate_aom_config_templates.cmake
index 8fbb4737ba..b91c036de8 100644
--- a/third_party/aom/build/cmake/generate_aom_config_templates.cmake
+++ b/third_party/aom/build/cmake/generate_aom_config_templates.cmake
@@ -78,23 +78,24 @@ if(NOT EXISTS "${AOM_DEFAULTS}")
 endif()
 
 include("${AOM_ROOT}/build/cmake/aom_config_defaults.cmake")
-get_cmake_property(cmake_cache_vars CACHE_VARIABLES)
+list(APPEND aom_build_vars ${AOM_DETECT_VARS} ${AOM_CONFIG_VARS})
+list(SORT aom_build_vars)
 
 set(aom_config_h_template "${AOM_CONFIG_DIR}/config/aom_config.h.cmake")
 file(WRITE "${aom_config_h_template}" ${h_file_header_block})
-foreach(cache_var ${cmake_cache_vars})
-  if(NOT "${cache_var}" MATCHES "AOM_CONFIG_DIR\|AOM_ROOT\|^CMAKE_")
+foreach(aom_var ${aom_build_vars})
+  if(NOT "${aom_var}" STREQUAL "AOM_RTCD_FLAGS")
     file(APPEND "${aom_config_h_template}"
-                "\#define ${cache_var} \${${cache_var}}\n")
+                "\#define ${aom_var} \${${aom_var}}\n")
   endif()
 endforeach()
-file(APPEND "${aom_config_h_template}" "\#endif  /* AOM_CONFIG_H_ */")
+file(APPEND "${aom_config_h_template}" "\#endif  // AOM_CONFIG_H_")
 
 set(aom_asm_config_template "${AOM_CONFIG_DIR}/config/aom_config.asm.cmake")
 file(WRITE "${aom_asm_config_template}" ${asm_file_header_block})
-foreach(cache_var ${cmake_cache_vars})
-  if(NOT "${cache_var}" MATCHES "AOM_CONFIG_DIR\|AOM_ROOT\|^CMAKE_\|INLINE")
-    file(APPEND "${aom_asm_config_template}"
-                "${cache_var} equ \${${cache_var}}\n")
+foreach(aom_var ${aom_build_vars})
+  if(NOT "${aom_var}" STREQUAL "INLINE" AND NOT "${aom_var}" STREQUAL
+     "AOM_RTCD_FLAGS")
+    file(APPEND "${aom_asm_config_template}" "${aom_var} equ \${${aom_var}}\n")
   endif()
 endforeach()
diff --git a/third_party/aom/build/cmake/generate_exports.cmake b/third_party/aom/build/cmake/generate_exports.cmake
index 4dce3a6715..7ab5aaef89 100644
--- a/third_party/aom/build/cmake/generate_exports.cmake
+++ b/third_party/aom/build/cmake/generate_exports.cmake
@@ -24,9 +24,7 @@ include("${AOM_ROOT}/build/cmake/exports_sources.cmake")
 if("${AOM_TARGET_SYSTEM}" STREQUAL "Darwin")
   set(symbol_prefix "_")
 elseif("${AOM_TARGET_SYSTEM}" MATCHES "Windows\|MSYS" AND AOM_MSVC)
-  set(symbol_prefix "_")
-  file(WRITE "${AOM_SYM_FILE}" "LIBRARY libaom INITINSTANCE TERMINSTANCE\n"
-             "DATA MULTIPLE NONSHARED\n" "EXPORTS\n")
+  file(WRITE "${AOM_SYM_FILE}" "LIBRARY aom\n" "EXPORTS\n")
 else()
   set(symbol_suffix ";")
 endif()
@@ -35,11 +33,10 @@ set(aom_sym_file "${AOM_SYM_FILE}")
 
 if("${AOM_TARGET_SYSTEM}" STREQUAL "Darwin")
   file(REMOVE "${aom_sym_file}")
-elseif("${AOM_TARGET_SYSTEM}" MATCHES "Windows\|MSYS")
-  file(WRITE "${aom_sym_file}" "LIBRARY libaom INITINSTANCE TERMINSTANCE\n"
-             "DATA MULTIPLE NONSHARED\n" "EXPORTS\n")
+elseif("${AOM_TARGET_SYSTEM}" MATCHES "Windows\|MSYS" AND AOM_MSVC)
+  file(WRITE "${aom_sym_file}" "LIBRARY aom\n" "EXPORTS\n")
 else()
-  file(WRITE "${aom_sym_file}" "{ global:\n")
+  file(WRITE "${aom_sym_file}" "{\nglobal:\n")
 endif()
 
 foreach(export_file ${AOM_EXPORTS_SOURCES})
@@ -50,11 +47,20 @@ endforeach()
 
 foreach(exported_symbol ${exported_symbols})
   string(STRIP "${exported_symbol}" exported_symbol)
+  if("${AOM_TARGET_SYSTEM}" MATCHES "Windows\|MSYS" AND AOM_MSVC)
+    string(SUBSTRING ${exported_symbol} 0 4 export_type)
+    string(COMPARE EQUAL "${export_type}" "data" is_data)
+    if(is_data)
+      set(symbol_suffix " DATA")
+    else()
+      set(symbol_suffix "")
+    endif()
+  endif()
   string(REGEX REPLACE "text \|data " "" "exported_symbol" "${exported_symbol}")
-  set(exported_symbol "${symbol_prefix}${exported_symbol}${symbol_suffix}")
+  set(exported_symbol "  ${symbol_prefix}${exported_symbol}${symbol_suffix}")
   file(APPEND "${aom_sym_file}" "${exported_symbol}\n")
 endforeach()
 
 if("${aom_sym_file}" MATCHES "ver$")
-  file(APPEND "${aom_sym_file}" " };")
+  file(APPEND "${aom_sym_file}" " \nlocal:\n  *;\n};")
 endif()
diff --git a/third_party/aom/build/make/ios-Info.plist b/third_party/aom/build/cmake/ios-Info.plist
index 300e3e310d..300e3e310d 100644
--- a/third_party/aom/build/make/ios-Info.plist
+++ b/third_party/aom/build/cmake/ios-Info.plist
diff --git a/third_party/aom/build/make/iosbuild.sh b/third_party/aom/build/cmake/iosbuild.sh
index 167ece200a..167ece200a 100755
--- a/third_party/aom/build/make/iosbuild.sh
+++ b/third_party/aom/build/cmake/iosbuild.sh
diff --git a/third_party/aom/build/make/rtcd.pl b/third_party/aom/build/cmake/rtcd.pl
index b849a1eba0..46e06907cc 100755
--- a/third_party/aom/build/make/rtcd.pl
+++ b/third_party/aom/build/cmake/rtcd.pl
@@ -304,7 +304,7 @@ sub arm() {
 #include "aom_ports/arm.h"
 static void setup_rtcd_internal(void)
 {
-    int flags = arm_cpu_caps();
+    int flags = aom_arm_cpu_caps();
 
     (void)flags;
 
@@ -409,12 +409,13 @@ EOF
 #
 
 &require("c");
+&require(keys %required);
 if ($opts{arch} eq 'x86') {
   @ALL_ARCHS = filter(qw/mmx sse sse2 sse3 ssse3 sse4_1 sse4_2 avx avx2/);
   x86;
 } elsif ($opts{arch} eq 'x86_64') {
   @ALL_ARCHS = filter(qw/mmx sse sse2 sse3 ssse3 sse4_1 sse4_2 avx avx2/);
-  @REQUIRES = filter(keys %required ? keys %required : qw/mmx sse sse2/);
+  @REQUIRES = filter(qw/mmx sse sse2/);
   &require(@REQUIRES);
   x86;
 } elsif ($opts{arch} eq 'mips32' || $opts{arch} eq 'mips64') {
@@ -430,6 +431,7 @@ if ($opts{arch} eq 'x86') {
   arm;
 } elsif ($opts{arch} eq 'armv8' || $opts{arch} eq 'arm64' ) {
   @ALL_ARCHS = filter(qw/neon/);
+  &require("neon");
   arm;
 } elsif ($opts{arch} eq 'ppc') {
   @ALL_ARCHS = filter(qw/vsx/);
diff --git a/third_party/aom/build/cmake/util.cmake b/third_party/aom/build/cmake/util.cmake
index a0c705691c..b70ec40137 100644
--- a/third_party/aom/build/cmake/util.cmake
+++ b/third_party/aom/build/cmake/util.cmake
@@ -13,19 +13,21 @@ if(AOM_BUILD_CMAKE_UTIL_CMAKE_)
 endif() # AOM_BUILD_CMAKE_UTIL_CMAKE_
 set(AOM_BUILD_CMAKE_UTIL_CMAKE_ 1)
 
+# Directory where generated sources will be written.
+set(AOM_GEN_SRC_DIR "${AOM_CONFIG_DIR}/gen_src")
+
 # Creates dummy source file in $AOM_CONFIG_DIR named $basename.$extension and
 # returns the full path to the dummy source file via the $out_file_path
 # parameter.
-function(create_dummy_source_file basename extension out_file_path)
-  set(dummy_source_file "${AOM_CONFIG_DIR}/${basename}_dummy.${extension}")
+macro(create_dummy_source_file basename extension out_file_path)
+  set(dummy_source_file "${AOM_GEN_SRC_DIR}/${basename}_dummy.${extension}")
   file(
     WRITE
       "${dummy_source_file}" "// Generated file. DO NOT EDIT!\n"
       "// ${target_name} needs a ${extension} file to force link language, \n"
       "// or to silence a harmless CMake warning: Ignore me.\n"
       "void ${target_name}_dummy_function(void) {}\n")
-  set(${out_file_path} ${dummy_source_file} PARENT_SCOPE)
-endfunction()
+endmacro()
 
 # Convenience function for adding a dummy source file to $target_name using
 # $extension as the file extension. Wraps create_dummy_source_file().
@@ -86,3 +88,84 @@ function(set_compiler_launcher launcher_flag launcher_name)
   endif()
 endfunction()
 
+# Sentinel value used to detect when a variable has been set via the -D argument
+# passed to CMake on the command line.
+set(cmake_cmdline_helpstring "No help, variable specified on the command line.")
+
+# Wrapper macro for set() that does some book keeping to help with storage of
+# build configuration information.
+#
+# Sets the default value for variable $name when the value of $name has not
+# already been set via the CMake command line.
+#
+# The names of variables defaulted through this macro are added to
+# $AOM_CONFIG_VARS to facilitate build logging and diagnostics.
+macro(set_aom_detect_var name value type helpstring)
+  unset(list_index)
+  list(FIND AOM_DETECT_VARS ${name} list_index)
+  if(${list_index} EQUAL -1)
+    list(APPEND AOM_DETECT_VARS ${name})
+  endif()
+
+  # Update the variable only when it does not carry the CMake assigned help
+  # string for variables specified via the command line.
+  unset(cache_helpstring)
+  get_property(cache_helpstring CACHE ${name} PROPERTY HELPSTRING)
+  if(NOT "${cache_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    set(${name} ${value} CACHE ${type} "${helpstring}")
+    mark_as_advanced(${name})
+  else()
+    message(
+      WARNING
+        "${name} has been set by CMake, but it may be overridden by the build "
+        "system during environment detection")
+  endif()
+endmacro()
+
+# Wrapper macro for set() that does some book keeping to help with storage of
+# build configuration information.
+#
+# Sets the default value for variable $name when the value of $name has not
+# already been set via the CMake command line.
+#
+# The names of variables defaulted through this macro are added to
+# $AOM_CONFIG_VARS to facilitate build logging and diagnostics.
+macro(set_aom_config_var name value type helpstring)
+  unset(list_index)
+  list(FIND AOM_CONFIG_VARS ${name} list_index)
+  if(${list_index} EQUAL -1)
+    list(APPEND AOM_CONFIG_VARS ${name})
+  endif()
+
+  # Update the variable only when it does not carry the CMake assigned help
+  # string for variables specified via the command line.
+  unset(cache_helpstring)
+  get_property(cache_helpstring CACHE ${name} PROPERTY HELPSTRING)
+  if(NOT "${cache_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    set(${name} ${value} CACHE ${type} "${helpstring}")
+  endif()
+endmacro()
+
+# Wrapper macro for option() that does some book keeping to help with storage of
+# build configuration information.
+#
+# Sets the default value for variable $name when the value of $name has not
+# already been set via the CMake command line.
+#
+# The names of variables defaulted through this macro are added to
+# $AOM_OPTION_VARS to facilitate build logging and diagnostics.
+macro(set_aom_option_var name helpstring value)
+  unset(list_index)
+  list(FIND AOM_OPTION_VARS ${name} list_index)
+  if(${list_index} EQUAL -1)
+    list(APPEND AOM_OPTION_VARS ${name})
+  endif()
+
+  # Update the variable only when it does not carry the CMake assigned help
+  # string for variables specified via the command line.
+  unset(cache_helpstring)
+  get_property(cache_helpstring CACHE ${name} PROPERTY HELPSTRING)
+  if(NOT "${cache_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    option(${name} "${helpstring}" ${value})
+  endif()
+endmacro()
diff --git a/third_party/aom/build/cmake/version.pl b/third_party/aom/build/cmake/version.pl
index 7c0608aeba..7d23f2b277 100755
--- a/third_party/aom/build/cmake/version.pl
+++ b/third_party/aom/build/cmake/version.pl
@@ -14,7 +14,7 @@ use warnings;
 use 5.010;
 use Getopt::Long;
 
-my $git_desc;
+my $git_desc = '';
 my $version_data;
 my $version_filename;
 GetOptions('version_data=s' => \$version_data,
@@ -68,7 +68,7 @@ if (length($git_desc) > 0) {
 open(my $version_file, '>', $version_filename) or
   die("Cannot open $version_filename: $!");
 
-my $version_packed = "((VERSION_MAJOR<<16)|(VERSION_MINOR<<8)|(VERSION_PATCH))";
+my $version_packed = "((VERSION_MAJOR << 16) | (VERSION_MINOR << 8) | (VERSION_PATCH))";
 my $year = (localtime)[5] + 1900;
 my $lic_block = << "EOF";
 /*
@@ -91,7 +91,8 @@ $lic_block
 #define VERSION_MINOR $version_minor
 #define VERSION_PATCH $version_patch
 #define VERSION_EXTRA \"$version_extra\"
-#define VERSION_PACKED $version_packed
+#define VERSION_PACKED \\
+  $version_packed
 #define VERSION_STRING_NOSP \"$git_desc\"
 #define VERSION_STRING \" $git_desc\"
 EOF
@@ -102,7 +103,8 @@ $lic_block
 #define VERSION_MINOR $version_minor
 #define VERSION_PATCH $version_patch
 #define VERSION_EXTRA \"$version_extra\"
-#define VERSION_PACKED $version_packed
+#define VERSION_PACKED \\
+  $version_packed
 #define VERSION_STRING_NOSP \"v$version_string\"
 #define VERSION_STRING \" v$version_string\"
 EOF
diff --git a/third_party/aom/build/make/thumb.pm b/third_party/aom/build/make/thumb.pm
deleted file mode 100644
index 0a6629d78d..0000000000
--- a/third_party/aom/build/make/thumb.pm
+++ /dev/null
@@ -1,64 +0,0 @@
-#!/usr/bin/env perl
-##
-## 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.
-##
-
-package thumb;
-
-sub FixThumbInstructions($$)
-{
-    my $short_branches = $_[1];
-    my $branch_shift_offset = $short_branches ? 1 : 0;
-
-    # Write additions with shifts, such as "add r10, r11, lsl #8",
-    # in three operand form, "add r10, r10, r11, lsl #8".
-    s/(add\s+)(r\d+),\s*(r\d+),\s*(lsl #\d+)/$1$2, $2, $3, $4/g;
-
-    # Convert additions with a non-constant shift into a sequence
-    # with left shift, addition and a right shift (to restore the
-    # register to the original value). Currently the right shift
-    # isn't necessary in the code base since the values in these
-    # registers aren't used, but doing the shift for consistency.
-    # This converts instructions such as "add r12, r12, r5, lsl r4"
-    # into the sequence "lsl r5, r4", "add r12, r12, r5", "lsr r5, r4".
-    s/^(\s*)(add)(\s+)(r\d+),\s*(r\d+),\s*(r\d+),\s*lsl (r\d+)/$1lsl$3$6, $7\n$1$2$3$4, $5, $6\n$1lsr$3$6, $7/g;
-
-    # Convert loads with right shifts in the indexing into a
-    # sequence of an add, load and sub. This converts
-    # "ldrb r4, [r9, lr, asr #1]" into "add r9, r9, lr, asr #1",
-    # "ldrb r9, [r9]", "sub r9, r9, lr, asr #1".
-    s/^(\s*)(ldrb)(\s+)(r\d+),\s*\[(\w+),\s*(\w+),\s*(asr #\d+)\]/$1add $3$5, $5, $6, $7\n$1$2$3$4, [$5]\n$1sub $3$5, $5, $6, $7/g;
-
-    # Convert register indexing with writeback into a separate add
-    # instruction. This converts "ldrb r12, [r1, r2]!" into
-    # "ldrb r12, [r1, r2]", "add r1, r1, r2".
-    s/^(\s*)(ldrb)(\s+)(r\d+),\s*\[(\w+),\s*(\w+)\]!/$1$2$3$4, [$5, $6]\n$1add $3$5, $6/g;
-
-    # Convert negative register indexing into separate sub/add instructions.
-    # This converts "ldrne r4, [src, -pstep, lsl #1]" into
-    # "subne src, src, pstep, lsl #1", "ldrne r4, [src]",
-    # "addne src, src, pstep, lsl #1". In a couple of cases where
-    # this is used, it's used for two subsequent load instructions,
-    # where a hand-written version of it could merge two subsequent
-    # add and sub instructions.
-    s/^(\s*)((ldr|str|pld)(ne)?)(\s+)(r\d+,\s*)?\[(\w+), -([^\]]+)\]/$1sub$4$5$7, $7, $8\n$1$2$5$6\[$7\]\n$1add$4$5$7, $7, $8/g;
-
-    # Convert register post indexing to a separate add instruction.
-    # This converts "ldrneb r9, [r0], r2" into "ldrneb r9, [r0]",
-    # "addne r0, r0, r2".
-    s/^(\s*)((ldr|str)(ne)?[bhd]?)(\s+)(\w+),(\s*\w+,)?\s*\[(\w+)\],\s*(\w+)/$1$2$5$6,$7 [$8]\n$1add$4$5$8, $8, $9/g;
-
-    # Convert "mov pc, lr" into "bx lr", since the former only works
-    # for switching from arm to thumb (and only in armv7), but not
-    # from thumb to arm.
-    s/mov(\s*)pc\s*,\s*lr/bx$1lr/g;
-}
-
-1;