diff --git a/webrtc/BUILD.gn b/webrtc/BUILD.gn
index 3a2556b917..01fa042af3 100644
--- a/webrtc/BUILD.gn
+++ b/webrtc/BUILD.gn
@@ -137,8 +137,6 @@ config("common_config") {
       defines += [ "WEBRTC_ARCH_ARM_V7" ]
       if (arm_use_neon) {
         defines += [ "WEBRTC_HAS_NEON" ]
-      } else if (arm_optionally_use_neon) {
-        defines += [ "WEBRTC_DETECT_NEON" ]
       }
     }
   }
diff --git a/webrtc/build/common.gypi b/webrtc/build/common.gypi
index 17c9959288..26acf4b5e2 100644
--- a/webrtc/build/common.gypi
+++ b/webrtc/build/common.gypi
@@ -221,7 +221,7 @@
       ['target_arch=="arm" or target_arch=="arm64" or target_arch=="mipsel"', {
         'prefer_fixed_point%': 1,
       }],
-      ['(target_arch=="arm" and (arm_neon==1 or arm_neon_optional==1)) or target_arch=="arm64"', {
+      ['(target_arch=="arm" and arm_neon==1) or target_arch=="arm64"', {
         'build_with_neon%': 1,
       }],
       ['OS!="ios" and (target_arch!="arm" or arm_version>=7) and target_arch!="mips64el"', {
@@ -352,9 +352,6 @@
               ['arm_neon==1', {
                 'defines': ['WEBRTC_HAS_NEON',],
               }],
-              ['arm_neon==0 and arm_neon_optional==1', {
-                'defines': ['WEBRTC_DETECT_NEON',],
-              }],
             ],
           }],
         ],
diff --git a/webrtc/build/webrtc.gni b/webrtc/build/webrtc.gni
index cef6651356..788e60824c 100644
--- a/webrtc/build/webrtc.gni
+++ b/webrtc/build/webrtc.gni
@@ -85,8 +85,7 @@ declare_args() {
 
   # Determines whether NEON code will be built.
   rtc_build_with_neon =
-      (current_cpu == "arm" && (arm_use_neon || arm_optionally_use_neon)) ||
-      current_cpu == "arm64"
+      (current_cpu == "arm" && arm_use_neon) || current_cpu == "arm64"
 
   # Enable this to use HW H.264 encoder/decoder on iOS PeerConnections.
   # Enabling this may break interop with Android clients that support H264.
diff --git a/webrtc/common_audio/fir_filter.cc b/webrtc/common_audio/fir_filter.cc
index 13a2237dae..ed1f1bbfb8 100644
--- a/webrtc/common_audio/fir_filter.cc
+++ b/webrtc/common_audio/fir_filter.cc
@@ -61,13 +61,6 @@ FIRFilter* FIRFilter::Create(const float* coefficients,
 #elif defined(WEBRTC_HAS_NEON)
   filter =
       new FIRFilterNEON(coefficients, coefficients_length, max_input_length);
-#elif defined(WEBRTC_DETECT_NEON)
-  if (WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) {
-    filter =
-        new FIRFilterNEON(coefficients, coefficients_length, max_input_length);
-  } else {
-    filter = new FIRFilterC(coefficients, coefficients_length);
-  }
 #else
   filter = new FIRFilterC(coefficients, coefficients_length);
 #endif
diff --git a/webrtc/common_audio/resampler/sinc_resampler.cc b/webrtc/common_audio/resampler/sinc_resampler.cc
index 69ac2208cf..c8bc15a362 100644
--- a/webrtc/common_audio/resampler/sinc_resampler.cc
+++ b/webrtc/common_audio/resampler/sinc_resampler.cc
@@ -136,12 +136,6 @@ void SincResampler::InitializeCPUSpecificFeatures() {
 #elif defined(WEBRTC_HAS_NEON)
 #define CONVOLVE_FUNC Convolve_NEON
 void SincResampler::InitializeCPUSpecificFeatures() {}
-#elif defined(WEBRTC_DETECT_NEON)
-#define CONVOLVE_FUNC convolve_proc_
-void SincResampler::InitializeCPUSpecificFeatures() {
-  convolve_proc_ = WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON ?
-      Convolve_NEON : Convolve_C;
-}
 #else
 // Unknown architecture.
 #define CONVOLVE_FUNC Convolve_C
diff --git a/webrtc/common_audio/resampler/sinc_resampler.h b/webrtc/common_audio/resampler/sinc_resampler.h
index d8ea6df72f..ecfd64c0a6 100644
--- a/webrtc/common_audio/resampler/sinc_resampler.h
+++ b/webrtc/common_audio/resampler/sinc_resampler.h
@@ -107,7 +107,7 @@ class SincResampler {
   static float Convolve_SSE(const float* input_ptr, const float* k1,
                             const float* k2,
                             double kernel_interpolation_factor);
-#elif defined(WEBRTC_DETECT_NEON) || defined(WEBRTC_HAS_NEON)
+#elif defined(WEBRTC_HAS_NEON)
   static float Convolve_NEON(const float* input_ptr, const float* k1,
                              const float* k2,
                              double kernel_interpolation_factor);
diff --git a/webrtc/common_audio/signal_processing/include/signal_processing_library.h b/webrtc/common_audio/signal_processing/include/signal_processing_library.h
index 2e96883e6d..19379bf084 100644
--- a/webrtc/common_audio/signal_processing/include/signal_processing_library.h
+++ b/webrtc/common_audio/signal_processing/include/signal_processing_library.h
@@ -106,10 +106,8 @@ extern "C" {
 
 // Initialize SPL. Currently it contains only function pointer initialization.
 // If the underlying platform is known to be ARM-Neon (WEBRTC_HAS_NEON defined),
-// the pointers will be assigned to code optimized for Neon; otherwise
-// if run-time Neon detection (WEBRTC_DETECT_NEON) is enabled, the pointers
-// will be assigned to either Neon code or generic C code; otherwise, generic C
-// code will be assigned.
+// the pointers will be assigned to code optimized for Neon; otherwise, generic
+// C code will be assigned.
 // Note that this function MUST be called in any application that uses SPL
 // functions.
 void WebRtcSpl_Init();
@@ -153,7 +151,7 @@ void WebRtcSpl_ZerosArrayW32(int32_t* vector,
 typedef int16_t (*MaxAbsValueW16)(const int16_t* vector, size_t length);
 extern MaxAbsValueW16 WebRtcSpl_MaxAbsValueW16;
 int16_t WebRtcSpl_MaxAbsValueW16C(const int16_t* vector, size_t length);
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 int16_t WebRtcSpl_MaxAbsValueW16Neon(const int16_t* vector, size_t length);
 #endif
 #if defined(MIPS32_LE)
@@ -170,7 +168,7 @@ int16_t WebRtcSpl_MaxAbsValueW16_mips(const int16_t* vector, size_t length);
 typedef int32_t (*MaxAbsValueW32)(const int32_t* vector, size_t length);
 extern MaxAbsValueW32 WebRtcSpl_MaxAbsValueW32;
 int32_t WebRtcSpl_MaxAbsValueW32C(const int32_t* vector, size_t length);
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 int32_t WebRtcSpl_MaxAbsValueW32Neon(const int32_t* vector, size_t length);
 #endif
 #if defined(MIPS_DSP_R1_LE)
@@ -187,7 +185,7 @@ int32_t WebRtcSpl_MaxAbsValueW32_mips(const int32_t* vector, size_t length);
 typedef int16_t (*MaxValueW16)(const int16_t* vector, size_t length);
 extern MaxValueW16 WebRtcSpl_MaxValueW16;
 int16_t WebRtcSpl_MaxValueW16C(const int16_t* vector, size_t length);
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 int16_t WebRtcSpl_MaxValueW16Neon(const int16_t* vector, size_t length);
 #endif
 #if defined(MIPS32_LE)
@@ -204,7 +202,7 @@ int16_t WebRtcSpl_MaxValueW16_mips(const int16_t* vector, size_t length);
 typedef int32_t (*MaxValueW32)(const int32_t* vector, size_t length);
 extern MaxValueW32 WebRtcSpl_MaxValueW32;
 int32_t WebRtcSpl_MaxValueW32C(const int32_t* vector, size_t length);
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 int32_t WebRtcSpl_MaxValueW32Neon(const int32_t* vector, size_t length);
 #endif
 #if defined(MIPS32_LE)
@@ -221,7 +219,7 @@ int32_t WebRtcSpl_MaxValueW32_mips(const int32_t* vector, size_t length);
 typedef int16_t (*MinValueW16)(const int16_t* vector, size_t length);
 extern MinValueW16 WebRtcSpl_MinValueW16;
 int16_t WebRtcSpl_MinValueW16C(const int16_t* vector, size_t length);
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 int16_t WebRtcSpl_MinValueW16Neon(const int16_t* vector, size_t length);
 #endif
 #if defined(MIPS32_LE)
@@ -238,7 +236,7 @@ int16_t WebRtcSpl_MinValueW16_mips(const int16_t* vector, size_t length);
 typedef int32_t (*MinValueW32)(const int32_t* vector, size_t length);
 extern MinValueW32 WebRtcSpl_MinValueW32;
 int32_t WebRtcSpl_MinValueW32C(const int32_t* vector, size_t length);
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 int32_t WebRtcSpl_MinValueW32Neon(const int32_t* vector, size_t length);
 #endif
 #if defined(MIPS32_LE)
@@ -531,7 +529,7 @@ void WebRtcSpl_CrossCorrelationC(int32_t* cross_correlation,
                                  size_t dim_cross_correlation,
                                  int right_shifts,
                                  int step_seq2);
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 void WebRtcSpl_CrossCorrelationNeon(int32_t* cross_correlation,
                                     const int16_t* seq1,
                                     const int16_t* seq2,
@@ -698,7 +696,7 @@ int WebRtcSpl_DownsampleFastC(const int16_t* data_in,
                               size_t coefficients_length,
                               int factor,
                               size_t delay);
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 int WebRtcSpl_DownsampleFastNeon(const int16_t* data_in,
                                  size_t data_in_length,
                                  int16_t* data_out,
diff --git a/webrtc/common_audio/signal_processing/spl_init.c b/webrtc/common_audio/signal_processing/spl_init.c
index fdab038399..c9c4e659cf 100644
--- a/webrtc/common_audio/signal_processing/spl_init.c
+++ b/webrtc/common_audio/signal_processing/spl_init.c
@@ -28,8 +28,7 @@ CrossCorrelation WebRtcSpl_CrossCorrelation;
 DownsampleFast WebRtcSpl_DownsampleFast;
 ScaleAndAddVectorsWithRound WebRtcSpl_ScaleAndAddVectorsWithRound;
 
-#if (defined(WEBRTC_DETECT_NEON) || !defined(WEBRTC_HAS_NEON)) && \
-    !defined(MIPS32_LE)
+#if (!defined(WEBRTC_HAS_NEON)) && !defined(MIPS32_LE)
 /* Initialize function pointers to the generic C version. */
 static void InitPointersToC() {
   WebRtcSpl_MaxAbsValueW16 = WebRtcSpl_MaxAbsValueW16C;
@@ -45,7 +44,7 @@ static void InitPointersToC() {
 }
 #endif
 
-#if defined(WEBRTC_DETECT_NEON) || defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 /* Initialize function pointers to the Neon version. */
 static void InitPointersToNeon() {
   WebRtcSpl_MaxAbsValueW16 = WebRtcSpl_MaxAbsValueW16Neon;
@@ -84,19 +83,13 @@ static void InitPointersToMIPS() {
 #endif
 
 static void InitFunctionPointers(void) {
-#if defined(WEBRTC_DETECT_NEON)
-  if ((WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) != 0) {
-    InitPointersToNeon();
-  } else {
-    InitPointersToC();
-  }
-#elif defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
   InitPointersToNeon();
 #elif defined(MIPS32_LE)
   InitPointersToMIPS();
 #else
   InitPointersToC();
-#endif  /* WEBRTC_DETECT_NEON */
+#endif  /* WEBRTC_HAS_NEON */
 }
 
 #if defined(WEBRTC_POSIX)
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/source/codec.h b/webrtc/modules/audio_coding/codecs/isac/fix/source/codec.h
index fdbb2fcb0d..001a04f39b 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/source/codec.h
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/source/codec.h
@@ -90,7 +90,7 @@ void WebRtcIsacfix_Spec2TimeC(int16_t* inreQ7,
                               int32_t* outre1Q16,
                               int32_t* outre2Q16);
 
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 void WebRtcIsacfix_Time2SpecNeon(int16_t* inre1Q9,
                                  int16_t* inre2Q9,
                                  int16_t* outre,
@@ -174,7 +174,7 @@ void WebRtcIsacfix_FilterMaLoopC(int16_t input0,
                                  int32_t* ptr1,
                                  int32_t* ptr2);
 
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 int WebRtcIsacfix_AutocorrNeon(int32_t* __restrict r,
                                const int16_t* __restrict x,
                                int16_t N,
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/source/entropy_coding.h b/webrtc/modules/audio_coding/codecs/isac/fix/source/entropy_coding.h
index 2c8c923cd3..1b87d0ea55 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/source/entropy_coding.h
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/source/entropy_coding.h
@@ -147,7 +147,7 @@ void WebRtcIsacfix_MatrixProduct2C(const int16_t matrix0[],
                                    const int matrix0_index_factor,
                                    const int matrix0_index_step);
 
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 void WebRtcIsacfix_MatrixProduct1Neon(const int16_t matrix0[],
                                       const int32_t matrix1[],
                                       int32_t matrix_product[],
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/source/filterbank_internal.h b/webrtc/modules/audio_coding/codecs/isac/fix/source/filterbank_internal.h
index 0e67e300ac..d488339b31 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/source/filterbank_internal.h
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/source/filterbank_internal.h
@@ -60,7 +60,7 @@ void WebRtcIsacfix_AllpassFilter2FixDec16C(
    int32_t *filter_state_ch1,
    int32_t *filter_state_ch2);
 
-#if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 void WebRtcIsacfix_AllpassFilter2FixDec16Neon(
    int16_t *data_ch1,
    int16_t *data_ch2,
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/source/filterbanks_unittest.cc b/webrtc/modules/audio_coding/codecs/isac/fix/source/filterbanks_unittest.cc
index 0ec115414b..4b03181e45 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/source/filterbanks_unittest.cc
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/source/filterbanks_unittest.cc
@@ -64,11 +64,7 @@ class FilterBanksTest : public testing::Test {
 
 TEST_F(FilterBanksTest, AllpassFilter2FixDec16Test) {
   CalculateResidualEnergyTester(WebRtcIsacfix_AllpassFilter2FixDec16C);
-#ifdef WEBRTC_DETECT_NEON
-  if ((WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) != 0) {
-    CalculateResidualEnergyTester(WebRtcIsacfix_AllpassFilter2FixDec16Neon);
-  }
-#elif defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
   CalculateResidualEnergyTester(WebRtcIsacfix_AllpassFilter2FixDec16Neon);
 #endif
 }
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/source/filters_unittest.cc b/webrtc/modules/audio_coding/codecs/isac/fix/source/filters_unittest.cc
index 5cce1e9f0b..3ed57788a1 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/source/filters_unittest.cc
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/source/filters_unittest.cc
@@ -59,11 +59,7 @@ class FiltersTest : public testing::Test {
 
 TEST_F(FiltersTest, AutocorrFixTest) {
   FiltersTester(WebRtcIsacfix_AutocorrC);
-#ifdef WEBRTC_DETECT_NEON
-  if ((WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) != 0) {
-    FiltersTester(WebRtcIsacfix_AutocorrNeon);
-  }
-#elif defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
   FiltersTester(WebRtcIsacfix_AutocorrNeon);
 #endif
 }
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/source/isacfix.c b/webrtc/modules/audio_coding/codecs/isac/fix/source/isacfix.c
index aba3aa0c0b..e7905ae81f 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/source/isacfix.c
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/source/isacfix.c
@@ -201,7 +201,7 @@ int16_t WebRtcIsacfix_FreeInternal(ISACFIX_MainStruct *ISAC_main_inst)
  * This function initializes function pointers for ARM Neon platform.
  */
 
-#if defined(WEBRTC_DETECT_NEON) || defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 static void WebRtcIsacfix_InitNeon(void) {
   WebRtcIsacfix_AutocorrFix = WebRtcIsacfix_AutocorrNeon;
   WebRtcIsacfix_FilterMaLoopFix = WebRtcIsacfix_FilterMaLoopNeon;
@@ -253,11 +253,7 @@ static void InitFunctionPointers(void) {
   WebRtcIsacfix_MatrixProduct1 = WebRtcIsacfix_MatrixProduct1C;
   WebRtcIsacfix_MatrixProduct2 = WebRtcIsacfix_MatrixProduct2C;
 
-#ifdef WEBRTC_DETECT_NEON
-  if ((WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) != 0) {
-    WebRtcIsacfix_InitNeon();
-  }
-#elif defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
   WebRtcIsacfix_InitNeon();
 #endif
 
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/source/pitch_estimator_c.c b/webrtc/modules/audio_coding/codecs/isac/fix/source/pitch_estimator_c.c
index 18377dd370..0d881e8044 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/source/pitch_estimator_c.c
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/source/pitch_estimator_c.c
@@ -57,8 +57,6 @@ void WebRtcIsacfix_PCorr2Q32(const int16_t* in, int32_t* logcorQ8) {
     ysum32 += in[PITCH_CORR_LEN2 + k - 1] * in[PITCH_CORR_LEN2 + k - 1] >>
         scaling;
 
-    // TODO(zhongwei.yao): Move this function into a separate NEON code file so
-    // that WEBRTC_DETECT_NEON could take advantage of it.
 #ifdef WEBRTC_HAS_NEON
     {
       int32_t vbuff[4];
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/source/transform_unittest.cc b/webrtc/modules/audio_coding/codecs/isac/fix/source/transform_unittest.cc
index 58d890011f..c5cc87ffce 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/source/transform_unittest.cc
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/source/transform_unittest.cc
@@ -179,22 +179,14 @@ class TransformTest : public testing::Test {
 
 TEST_F(TransformTest, Time2SpecTest) {
   Time2SpecTester(WebRtcIsacfix_Time2SpecC);
-#ifdef WEBRTC_DETECT_NEON
-  if ((WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) != 0) {
-    Time2SpecTester(WebRtcIsacfix_Time2SpecNeon);
-  }
-#elif defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
   Time2SpecTester(WebRtcIsacfix_Time2SpecNeon);
 #endif
 }
 
 TEST_F(TransformTest, Spec2TimeTest) {
   Spec2TimeTester(WebRtcIsacfix_Spec2TimeC);
-#ifdef WEBRTC_DETECT_NEON
-  if ((WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) != 0) {
-    Spec2TimeTester(WebRtcIsacfix_Spec2TimeNeon);
-  }
-#elif defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
   Spec2TimeTester(WebRtcIsacfix_Spec2TimeNeon);
 #endif
 }
diff --git a/webrtc/modules/audio_processing/aec/aec_core.cc b/webrtc/modules/audio_processing/aec/aec_core.cc
index b463597aba..2cb6dd2ce7 100644
--- a/webrtc/modules/audio_processing/aec/aec_core.cc
+++ b/webrtc/modules/audio_processing/aec/aec_core.cc
@@ -1486,10 +1486,6 @@ AecCore* WebRtcAec_CreateAec(int instance_count) {
 
 #if defined(WEBRTC_HAS_NEON)
   WebRtcAec_InitAec_neon();
-#elif defined(WEBRTC_DETECT_NEON)
-  if ((WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) != 0) {
-    WebRtcAec_InitAec_neon();
-  }
 #endif
 
   aec_rdft_init();
diff --git a/webrtc/modules/audio_processing/aec/aec_core.h b/webrtc/modules/audio_processing/aec/aec_core.h
index 668b484195..1ab2020186 100644
--- a/webrtc/modules/audio_processing/aec/aec_core.h
+++ b/webrtc/modules/audio_processing/aec/aec_core.h
@@ -239,7 +239,7 @@ void WebRtcAec_InitAec_SSE2(void);
 #if defined(MIPS_FPU_LE)
 void WebRtcAec_InitAec_mips(void);
 #endif
-#if defined(WEBRTC_DETECT_NEON) || defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 void WebRtcAec_InitAec_neon(void);
 #endif
 
diff --git a/webrtc/modules/audio_processing/aec/aec_rdft.cc b/webrtc/modules/audio_processing/aec/aec_rdft.cc
index 03efc103ea..690fe9f34f 100644
--- a/webrtc/modules/audio_processing/aec/aec_rdft.cc
+++ b/webrtc/modules/audio_processing/aec/aec_rdft.cc
@@ -581,9 +581,5 @@ void aec_rdft_init(void) {
 #endif
 #if defined(WEBRTC_HAS_NEON)
   aec_rdft_init_neon();
-#elif defined(WEBRTC_DETECT_NEON)
-  if ((WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) != 0) {
-    aec_rdft_init_neon();
-  }
 #endif
 }
diff --git a/webrtc/modules/audio_processing/aec/aec_rdft.h b/webrtc/modules/audio_processing/aec/aec_rdft.h
index 18eb7a5c3f..d83eb27d83 100644
--- a/webrtc/modules/audio_processing/aec/aec_rdft.h
+++ b/webrtc/modules/audio_processing/aec/aec_rdft.h
@@ -54,7 +54,7 @@ void aec_rdft_inverse_128(float* a);
 #if defined(MIPS_FPU_LE)
 void aec_rdft_init_mips(void);
 #endif
-#if defined(WEBRTC_DETECT_NEON) || defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 void aec_rdft_init_neon(void);
 #endif
 
diff --git a/webrtc/modules/audio_processing/aecm/aecm_core.cc b/webrtc/modules/audio_processing/aecm/aecm_core.cc
index efaa7f0a8f..a17220dbd7 100644
--- a/webrtc/modules/audio_processing/aecm/aecm_core.cc
+++ b/webrtc/modules/audio_processing/aecm/aecm_core.cc
@@ -365,7 +365,7 @@ static void ResetAdaptiveChannelC(AecmCore* aecm) {
 }
 
 // Initialize function pointers for ARM Neon platform.
-#if (defined WEBRTC_DETECT_NEON || defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 static void WebRtcAecm_InitNeon(void)
 {
   WebRtcAecm_StoreAdaptiveChannel = WebRtcAecm_StoreAdaptiveChannelNeon;
@@ -512,13 +512,7 @@ int WebRtcAecm_InitCore(AecmCore* const aecm, int samplingFreq) {
     WebRtcAecm_StoreAdaptiveChannel = StoreAdaptiveChannelC;
     WebRtcAecm_ResetAdaptiveChannel = ResetAdaptiveChannelC;
 
-#ifdef WEBRTC_DETECT_NEON
-    uint64_t features = WebRtc_GetCPUFeaturesARM();
-    if ((features & kCPUFeatureNEON) != 0)
-    {
-      WebRtcAecm_InitNeon();
-    }
-#elif defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
     WebRtcAecm_InitNeon();
 #endif
 
diff --git a/webrtc/modules/audio_processing/aecm/aecm_core.h b/webrtc/modules/audio_processing/aecm/aecm_core.h
index 421a8365c2..33d80889aa 100644
--- a/webrtc/modules/audio_processing/aecm/aecm_core.h
+++ b/webrtc/modules/audio_processing/aecm/aecm_core.h
@@ -402,7 +402,7 @@ extern ResetAdaptiveChannel WebRtcAecm_ResetAdaptiveChannel;
 // For the above function pointers, functions for generic platforms are declared
 // and defined as static in file aecm_core.c, while those for ARM Neon platforms
 // are declared below and defined in file aecm_core_neon.c.
-#if defined(WEBRTC_DETECT_NEON) || defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 void WebRtcAecm_CalcLinearEnergiesNeon(AecmCore* aecm,
                                        const uint16_t* far_spectrum,
                                        int32_t* echo_est,
diff --git a/webrtc/modules/audio_processing/ns/nsx_core.c b/webrtc/modules/audio_processing/ns/nsx_core.c
index 25f16d26ab..94b6449776 100644
--- a/webrtc/modules/audio_processing/ns/nsx_core.c
+++ b/webrtc/modules/audio_processing/ns/nsx_core.c
@@ -19,7 +19,7 @@
 #include "webrtc/modules/audio_processing/ns/nsx_core.h"
 #include "webrtc/system_wrappers/include/cpu_features_wrapper.h"
 
-#if (defined WEBRTC_DETECT_NEON || defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 /* Tables are defined in ARM assembly files. */
 extern const int16_t WebRtcNsx_kLogTable[9];
 extern const int16_t WebRtcNsx_kCounterDiv[201];
@@ -65,7 +65,7 @@ static const int16_t WebRtcNsx_kLogTableFrac[256] = {
   237, 238, 238, 239, 240, 241, 241, 242, 243, 244, 244, 245, 246, 247, 247,
   248, 249, 249, 250, 251, 252, 252, 253, 254, 255, 255
 };
-#endif  // WEBRTC_DETECT_NEON || WEBRTC_HAS_NEON
+#endif  // WEBRTC_HAS_NEON
 
 // Skip first frequency bins during estimation. (0 <= value < 64)
 static const size_t kStartBand = 5;
@@ -557,7 +557,7 @@ AnalysisUpdate WebRtcNsx_AnalysisUpdate;
 Denormalize WebRtcNsx_Denormalize;
 NormalizeRealBuffer WebRtcNsx_NormalizeRealBuffer;
 
-#if (defined WEBRTC_DETECT_NEON || defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 // Initialize function pointers for ARM Neon platform.
 static void WebRtcNsx_InitNeon(void) {
   WebRtcNsx_NoiseEstimation = WebRtcNsx_NoiseEstimationNeon;
@@ -762,12 +762,7 @@ int32_t WebRtcNsx_InitCore(NoiseSuppressionFixedC* inst, uint32_t fs) {
   WebRtcNsx_Denormalize = DenormalizeC;
   WebRtcNsx_NormalizeRealBuffer = NormalizeRealBufferC;
 
-#ifdef WEBRTC_DETECT_NEON
-  uint64_t features = WebRtc_GetCPUFeaturesARM();
-  if ((features & kCPUFeatureNEON) != 0) {
-      WebRtcNsx_InitNeon();
-  }
-#elif defined(WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
   WebRtcNsx_InitNeon();
 #endif
 
diff --git a/webrtc/modules/audio_processing/ns/nsx_core.h b/webrtc/modules/audio_processing/ns/nsx_core.h
index f463dbbe1a..d1754f31ea 100644
--- a/webrtc/modules/audio_processing/ns/nsx_core.h
+++ b/webrtc/modules/audio_processing/ns/nsx_core.h
@@ -215,7 +215,7 @@ void WebRtcNsx_SpeechNoiseProb(NoiseSuppressionFixedC* inst,
                                uint32_t* priorLocSnr,
                                uint32_t* postLocSnr);
 
-#if (defined WEBRTC_DETECT_NEON || defined WEBRTC_HAS_NEON)
+#if defined(WEBRTC_HAS_NEON)
 // For the above function pointers, functions for generic platforms are declared
 // and defined as static in file nsx_core.c, while those for ARM Neon platforms
 // are declared below and defined in file nsx_core_neon.c.
diff --git a/webrtc/modules/video_processing/util/denoiser_filter.cc b/webrtc/modules/video_processing/util/denoiser_filter.cc
index b111a0e412..376dec74a3 100644
--- a/webrtc/modules/video_processing/util/denoiser_filter.cc
+++ b/webrtc/modules/video_processing/util/denoiser_filter.cc
@@ -45,14 +45,6 @@ std::unique_ptr<DenoiserFilter> DenoiserFilter::Create(
     filter.reset(new DenoiserFilterNEON());
     if (cpu_type != nullptr)
       *cpu_type = CPU_NEON;
-#elif defined(WEBRTC_DETECT_NEON)
-    if (WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) {
-      filter.reset(new DenoiserFilterNEON());
-      if (cpu_type != nullptr)
-        *cpu_type = CPU_NEON;
-    } else {
-      filter.reset(new DenoiserFilterC());
-    }
 #else
     filter.reset(new DenoiserFilterC());
 #endif
diff --git a/webrtc/typedefs.h b/webrtc/typedefs.h
index 6a3f441e22..e65b77a65f 100644
--- a/webrtc/typedefs.h
+++ b/webrtc/typedefs.h
@@ -57,8 +57,7 @@
 
 // TODO(zhongwei.yao): WEBRTC_CPU_DETECTION is only used in one place; we should
 // probably just remove it.
-#if (defined(WEBRTC_ARCH_X86_FAMILY) && !defined(__SSE2__)) || \
-    defined(WEBRTC_DETECT_NEON)
+#if (defined(WEBRTC_ARCH_X86_FAMILY) && !defined(__SSE2__))
 #define WEBRTC_CPU_DETECTION
 #endif