diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7e5c5cd9f..6d6e615a3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -152,13 +152,17 @@ if (USE_CPU_EXTENSIONS)
                 )
         endif()
     elseif (AWS_ARCH_ARM64 OR AWS_ARCH_ARM32)
-        if (MSVC)
+        if (WINDOWS)
             file(GLOB AWS_COMMON_ARCH_SRC
-                "source/arch/arm/msvc/*.c"
+                "source/arch/arm/windows/*.c"
                 )
-        elseif (AWS_HAVE_AUXV)
+        elseif(APPLE)
+            file(GLOB AWS_COMMON_ARCH_SRC
+                    "source/arch/arm/darwin/*.c"
+                    )
+        else()
             file(GLOB AWS_COMMON_ARCH_SRC
-                "source/arch/arm/asm/*.c"
+                "source/arch/arm/auxv/*.c"
                 )
         endif()
     endif()
@@ -221,7 +225,7 @@ target_compile_definitions(${PROJECT_NAME} PRIVATE -DCJSON_HIDE_SYMBOLS)
 
 if (AWS_HAVE_AVX2_INTRINSICS)
     target_compile_definitions(${PROJECT_NAME} PRIVATE -DUSE_SIMD_ENCODING)
-    simd_add_source_avx(${PROJECT_NAME} "source/arch/intel/encoding_avx2.c")
+    simd_append_source_and_features(${PROJECT_NAME} "source/arch/intel/encoding_avx2.c" ${AWS_AVX2_FLAG})
     message(STATUS "Building SIMD base64 decoder")
 endif()
 
diff --git a/bin/system_info/print_system_info.c b/bin/system_info/print_system_info.c
index c29877086..aac1b570f 100644
--- a/bin/system_info/print_system_info.c
+++ b/bin/system_info/print_system_info.c
@@ -3,6 +3,7 @@
 #include <aws/common/byte_buf.h>
 #include <aws/common/logging.h>
 #include <aws/common/system_info.h>
+#include <aws/common/cpuid.h>
 
 int main(void) {
     struct aws_allocator *allocator = aws_default_allocator();
@@ -39,6 +40,19 @@ int main(void) {
         fprintf(stdout, "  'numa architecture': 'false'\n");
     }
 
+    fprintf(stdout, "   'cpu_capabilities': {\n");
+    fprintf(stdout, "       'arm_crc': %s,\n", aws_cpu_has_feature(AWS_CPU_FEATURE_ARM_CRC) ? "true" : "false");
+    fprintf(stdout, "       'arm_pmull': %s,\n", aws_cpu_has_feature(AWS_CPU_FEATURE_ARM_PMULL) ? "true" : "false");
+    fprintf(stdout, "       'arm_crypto': %s,\n", aws_cpu_has_feature(AWS_CPU_FEATURE_ARM_CRYPTO) ? "true" : "false");
+    fprintf(stdout, "       'amd_sse4_1': %s,\n", aws_cpu_has_feature(AWS_CPU_FEATURE_SSE_4_1) ? "true" : "false");
+    fprintf(stdout, "       'amd_sse4_2': %s,\n", aws_cpu_has_feature(AWS_CPU_FEATURE_SSE_4_2) ? "true" : "false");
+    fprintf(stdout, "       'amd_clmul': %s,\n", aws_cpu_has_feature(AWS_CPU_FEATURE_CLMUL) ? "true" : "false");
+    fprintf(stdout, "       'amd_vpclmulqdq': %s,\n", aws_cpu_has_feature(AWS_CPU_FEATURE_VPCLMULQDQ) ? "true" : "false");
+    fprintf(stdout, "       'amd_avx2': %s,\n", aws_cpu_has_feature(AWS_CPU_FEATURE_AVX2) ? "true" : "false");
+    fprintf(stdout, "       'amd_avx512': %s,\n", aws_cpu_has_feature(AWS_CPU_FEATURE_AVX512) ? "true" : "false");
+    fprintf(stdout, "       'amd_bmi2': %s\n", aws_cpu_has_feature(AWS_CPU_FEATURE_BMI2) ? "true" : "false");
+    fprintf(stdout, "   }\n");
+
     fprintf(stdout, "}\n");
     aws_system_environment_release(env);
     aws_logger_clean_up(&logger);
diff --git a/cmake/AwsFeatureTests.cmake b/cmake/AwsFeatureTests.cmake
index 60a548cfd..813a3c9f8 100644
--- a/cmake/AwsFeatureTests.cmake
+++ b/cmake/AwsFeatureTests.cmake
@@ -17,6 +17,10 @@ if(MINGW)
     set(USE_CPU_EXTENSIONS OFF)
 endif()
 
+if (USE_CPU_EXTENSIONS)
+    set(AWS_USE_CPU_EXTENSIONS ON)
+endif()
+
 if(NOT CMAKE_CROSSCOMPILING)
     check_c_source_runs("
     #include <stdbool.h>
@@ -54,6 +58,15 @@ check_c_source_compiles("
     }
 " AWS_ARCH_INTEL)
 
+check_c_source_compiles("
+    int main() {
+#if !(defined(__x86_64__) || defined(_M_X64))
+#    error \"not intel\"
+#endif
+        return 0;
+    }
+" AWS_ARCH_INTEL_X64)
+
 check_c_source_compiles("
     int main() {
 #if !(defined(__aarch64__) || defined(_M_ARM64))
diff --git a/cmake/AwsSIMD.cmake b/cmake/AwsSIMD.cmake
index 6ba9f236e..65fce96c7 100644
--- a/cmake/AwsSIMD.cmake
+++ b/cmake/AwsSIMD.cmake
@@ -4,35 +4,39 @@
 include(CheckCCompilerFlag)
 include(CheckIncludeFile)
 
+if (MSVC)
+    set(AWS_AVX2_FLAG "/arch:AVX2")
+    set(AWS_AVX512_FLAG "/arch:AVX512")
+    set(AWS_AVX512vL_FLAG "")
+    set(AWS_CLMUL_FLAG "")
+    set(AWS_SSE4_2_FLAG "")
+    set(AWS_ARMv8_1_FLAG "/arch:arm8.1")
+    set(WERROR_FLAG "")
+else()
+    set(AWS_AVX2_FLAG "-mavx -mavx2")
+    set(AWS_AVX512_FLAG "-mavx512f -mvpclmulqdq")
+    set(AWS_AVX512vL_FLAG "-mavx512vl")
+    set(AWS_CLMUL_FLAG "-mpclmul")
+    set(AWS_SSE4_2_FLAG "-msse4.2")
+    set(AWS_ARMv8_1_FLAG "-march=armv8-a+crc+crypto -mtune=neoverse-v1")
+    set(WERROR_FLAG "-Werror")
+endif()
+
 if (USE_CPU_EXTENSIONS)
-    if (MSVC)
-        check_c_compiler_flag("/arch:AVX2" HAVE_M_AVX2_FLAG)
-        if (HAVE_M_AVX2_FLAG)
-            set(AVX_CFLAGS "/arch:AVX2")
-        endif()
-    else()
-        check_c_compiler_flag(-mavx2 HAVE_M_AVX2_FLAG)
-        if (HAVE_M_AVX2_FLAG)
-            set(AVX_CFLAGS "-mavx -mavx2")
-        endif()
+    set(AVX_CFLAGS ${AWS_SSE4_2_FLAG})
+
+    check_c_compiler_flag(${AWS_AVX2_FLAG} HAVE_M_AVX2_FLAG)
+    if (HAVE_M_AVX2_FLAG)
+        set(AVX_CFLAGS "${AWS_AVX2_FLAG} ${AVX_CFLAGS}")
     endif()
 
-    if (MSVC)
-        check_c_compiler_flag("/arch:AVX512" HAVE_M_AVX512_FLAG)
-        if (HAVE_M_AVX512_FLAG)
-            # docs imply AVX512 brings in AVX2. And it will compile, but it will break at runtime on
-            # instructions such as _mm256_load_si256(). Leave it on.
-            set(AVX_CFLAGS "/arch:AVX512 /arch:AVX2")
-        endif()
-    else()
-        check_c_compiler_flag("-mavx512f -mvpclmulqdq" HAVE_M_AVX512_FLAG)
-        if (HAVE_M_AVX512_FLAG)
-            set(AVX_CFLAGS "-mavx512f -mvpclmulqdq -mpclmul -mavx -mavx2 -msse4.2")
-        endif()
+    check_c_compiler_flag("${AWS_AVX512_FLAG} ${AWS_CLMUL_FLAG}" HAVE_M_AVX512_FLAG)
+    if (HAVE_M_AVX512_FLAG)
+        set(AVX_CFLAGS "${AWS_AVX512_FLAG} ${AWS_CLMUL_FLAG} ${AVX_CFLAGS}")
     endif()
 
     set(old_flags "${CMAKE_REQUIRED_FLAGS}")
-    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${AVX_CFLAGS}")
+    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${AVX_CFLAGS} ${WERROR_FLAG}")
 
     check_c_source_compiles("
         #include <immintrin.h>
@@ -68,7 +72,35 @@ if (USE_CPU_EXTENSIONS)
             return (int)_mm256_extract_epi64(vec, 2);
         }" AWS_HAVE_MM256_EXTRACT_EPI64)
 
+    check_c_source_compiles("
+        #include <wmmintrin.h>
+        #include <emmintrin.h>
+        int main() {
+            __m128i a = _mm_setzero_si128();
+            __m128i b = _mm_setzero_si128();
+            __m128i result = _mm_clmulepi64_si128(a, b, 0x00);
+            (void)result;
+            return 0;
+        }" AWS_HAVE_CLMUL)
+
+    set(CMAKE_REQUIRED_FLAGS "${old_flags} ${AWS_ARMv8_1_FLAG} ${WERROR_FLAG}")
+    check_c_source_compiles("
+            #include <arm_acle.h>
+            int main() {
+                int crc = __crc32d(0, 1);
+                return 0;
+            }" AWS_HAVE_ARM32_CRC)
+
+    check_c_source_compiles("
+        #include <stdatomic.h>
+        int main() {
+            _Atomic int var = 0;
+            atomic_fetch_add_explicit(&var, 1, memory_order_relaxed);
+            return 0;
+    }" AWS_HAVE_ARMv8_1)
+
     set(CMAKE_REQUIRED_FLAGS "${old_flags}")
+
 endif() # USE_CPU_EXTENSIONS
 
 # The part where the definition is added to the compiler flags has been moved to config.h.in
@@ -80,6 +112,23 @@ endif() # USE_CPU_EXTENSIONS
 function(simd_add_source_avx target)
     foreach(file ${ARGN})
         target_sources(${target} PRIVATE ${file})
-        set_source_files_properties(${file} PROPERTIES COMPILE_FLAGS "${AVX_CFLAGS}")
+        set_source_files_properties(${file} PROPERTIES COMPILE_FLAGS " ${AVX_CFLAGS}")
     endforeach()
 endfunction(simd_add_source_avx)
+
+# The part where the definition is added to the compiler flags has been moved to config.h.in
+# see git history for more details.
+
+# Adds compiler flags to the source and adds the source to target.
+# Unfortunately the flags have to be passed as strings. Predefined flags are
+# at the top of this file.
+# Usage: simd_append_source_and_features(target file1.c ${AWS_AVX512_FLAG} ${AWS_AVX2_FLAG} ...)
+function(simd_append_source_and_features target file)
+    set(CC_FLAGS "")
+    foreach(flag ${ARGN})
+        set(CC_FLAGS "${CC_FLAGS} ${flag}")
+    endforeach()
+
+    target_sources(${target} PRIVATE ${file})
+    set_source_files_properties(${file} PROPERTIES COMPILE_FLAGS " ${CC_FLAGS}")
+endfunction(simd_append_source_and_features)
diff --git a/include/aws/common/config.h.in b/include/aws/common/config.h.in
index d3dff3af2..381d99c99 100644
--- a/include/aws/common/config.h.in
+++ b/include/aws/common/config.h.in
@@ -22,5 +22,12 @@
 #cmakedefine AWS_HAVE_AVX2_INTRINSICS
 #cmakedefine AWS_HAVE_AVX512_INTRINSICS
 #cmakedefine AWS_HAVE_MM256_EXTRACT_EPI64
+#cmakedefine AWS_HAVE_CLMUL
+#cmakedefine AWS_HAVE_ARM32_CRC
+#cmakedefine AWS_HAVE_ARMv8_1
+#cmakedefine AWS_ARCH_ARM64
+#cmakedefine AWS_ARCH_INTEL
+#cmakedefine AWS_ARCH_INTEL_X64
+#cmakedefine AWS_USE_CPU_EXTENSIONS
 
 #endif
diff --git a/include/aws/common/cpuid.h b/include/aws/common/cpuid.h
index 84024a36b..9ab7d5059 100644
--- a/include/aws/common/cpuid.h
+++ b/include/aws/common/cpuid.h
@@ -18,6 +18,8 @@ enum aws_cpu_feature_name {
     AWS_CPU_FEATURE_ARM_CRC,
     AWS_CPU_FEATURE_BMI2,
     AWS_CPU_FEATURE_VPCLMULQDQ,
+    AWS_CPU_FEATURE_ARM_PMULL,
+    AWS_CPU_FEATURE_ARM_CRYPTO,
     AWS_CPU_FEATURE_COUNT,
 };
 
diff --git a/source/arch/arm/asm/cpuid.c b/source/arch/arm/auxv/cpuid.c
similarity index 86%
rename from source/arch/arm/asm/cpuid.c
rename to source/arch/arm/auxv/cpuid.c
index 6a306df98..10499da73 100644
--- a/source/arch/arm/asm/cpuid.c
+++ b/source/arch/arm/auxv/cpuid.c
@@ -29,7 +29,9 @@ struct cap_bits {
 
 #    if (defined(__aarch64__))
 struct cap_bits s_check_cap[AWS_CPU_FEATURE_COUNT] = {
-    [AWS_CPU_FEATURE_ARM_CRC] = {0, 1 << 7 /* HWCAP_CRC */},
+    [AWS_CPU_FEATURE_ARM_CRC] = {0, 1 << 7 /* HWCAP_CRC32 */},
+    [AWS_CPU_FEATURE_ARM_PMULL] = {0, 1 << 4 /* HWCAP_PMULL */},
+    [AWS_CPU_FEATURE_ARM_CRYPTO] = {0, 1 << 3 /* HWCAP_AES */},
 };
 #    else
 struct cap_bits s_check_cap[AWS_CPU_FEATURE_COUNT] = {
@@ -67,6 +69,10 @@ bool aws_cpu_has_feature(enum aws_cpu_feature_name feature_name) {
 
     switch (feature_name) {
         case AWS_CPU_FEATURE_ARM_CRC:
+#    if (defined(__aarch64__))
+        case AWS_CPU_FEATURE_ARM_PMULL:
+        case AWS_CPU_FEATURE_ARM_CRYPTO:
+#    endif // (defined(__aarch64__))
             return s_hwcap[s_check_cap[feature_name].cap] & s_check_cap[feature_name].bit;
         default:
             return false;
diff --git a/source/arch/arm/darwin/cpuid.c b/source/arch/arm/darwin/cpuid.c
new file mode 100644
index 000000000..7552d4220
--- /dev/null
+++ b/source/arch/arm/darwin/cpuid.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+#include <aws/common/cpuid.h>
+
+#include <sys/sysctl.h>
+
+bool aws_cpu_has_feature(enum aws_cpu_feature_name feature_name) {
+    int64_t ret = 0;
+    size_t size = sizeof(ret);
+
+    switch (feature_name) {
+        case AWS_CPU_FEATURE_ARM_PMULL:
+            if (sysctlbyname("hw.optional.arm.FEAT_PMULL", &ret, &size, NULL, 0) != -1) {
+                return ret == 1;
+            }
+        case AWS_CPU_FEATURE_ARM_CRC:
+            if (sysctlbyname("hw.optional.armv8_crc32", &ret, &size, NULL, 0) != -1) {
+                return ret == 1;
+            }
+        case AWS_CPU_FEATURE_ARM_CRYPTO:
+            if (sysctlbyname("hw.optional.arm.FEAT_AES", &ret, &size, NULL, 0) != -1) {
+                return ret == 1;
+            }
+        default:
+            return false;
+    }
+}
diff --git a/source/arch/arm/msvc/cpuid.c b/source/arch/arm/windows/cpuid.c
similarity index 57%
rename from source/arch/arm/msvc/cpuid.c
rename to source/arch/arm/windows/cpuid.c
index c10c5d15c..b7da0053f 100644
--- a/source/arch/arm/msvc/cpuid.c
+++ b/source/arch/arm/windows/cpuid.c
@@ -13,9 +13,18 @@
  * permissions and limitations under the License.
  */
 
+#include <Windows.h>
 #include <aws/common/cpuid.h>
-#include <stdlib.h>
 
 bool aws_cpu_has_feature(enum aws_cpu_feature_name feature_name) {
-    return false;
+    switch (feature_name) {
+        case AWS_CPU_FEATURE_ARM_CRC:
+            return IsProcessorFeaturePresent(PF_ARM_V8_CRC32_INSTRUCTIONS_AVAILABLE) != 0;
+        // this is the best we've got on windows as they don't separate PMULL and AES from each other.
+        case AWS_CPU_FEATURE_ARM_PMULL:
+        case AWS_CPU_FEATURE_ARM_CRYPTO:
+            return IsProcessorFeaturePresent(PF_ARM_V8_CRYPTO_INSTRUCTIONS_AVAILABLE) != 0;
+        default:
+            return false;
+    }
 }
diff --git a/source/arch/intel/cpuid.c b/source/arch/intel/cpuid.c
index 44fdff078..465fccd17 100644
--- a/source/arch/intel/cpuid.c
+++ b/source/arch/intel/cpuid.c
@@ -116,8 +116,8 @@ static bool s_has_bmi2(void) {
 static bool s_has_vpclmulqdq(void) {
     uint32_t abcd[4];
     /* Check VPCLMULQDQ:
-     * CPUID.(EAX=07H, ECX=0H):ECX.VPCLMULQDQ[bit 20]==1 */
-    uint32_t vpclmulqdq_mask = (1 << 20);
+     * CPUID.(EAX=07H, ECX=0H):ECX.VPCLMULQDQ[bit 10]==1 */
+    uint32_t vpclmulqdq_mask = (1 << 10);
     aws_run_cpuid(7, 0, abcd);
     if ((abcd[2] & vpclmulqdq_mask) != vpclmulqdq_mask) {
         return false;