Add support for Apple M1 AArch64 SoCs (#204)

* Add support for Apple M1 AArch64 SoCs

Completely based on #150. Thanks to @sbehnke!
+ Refactoring to accomodate the new source tree
+ Adding more feature flags

* revert minimum version to 3.0

* Update introspection table

* Simplify logic for Apple HAVE_SYSCTLBYNAME

---------

Co-authored-by: Guillaume Chatelet <gchatelet@google.com>

7 files changed, 331 insertions, 127 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7679ff5..11fc433 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -63,7 +63,7 @@ set(PROCESSOR_IS_LOONGARCH FALSE)
 
 if(CMAKE_SYSTEM_PROCESSOR MATCHES "^mips")
   set(PROCESSOR_IS_MIPS TRUE)
-elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(aarch64|arm64)")
+elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "(^aarch64)|(^arm64)")
   set(PROCESSOR_IS_AARCH64 TRUE)
 elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm")
   set(PROCESSOR_IS_ARM TRUE)
@@ -160,10 +160,9 @@ target_link_libraries(cpu_features PUBLIC ${CMAKE_DL_LIBS})
 target_include_directories(cpu_features
   PUBLIC $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}/cpu_features>
 )
-if(PROCESSOR_IS_X86)
-  if(APPLE)
-    target_compile_definitions(cpu_features PRIVATE HAVE_SYSCTLBYNAME)
-  endif()
+
+if(APPLE)
+  target_compile_definitions(cpu_features PRIVATE HAVE_SYSCTLBYNAME)
 endif()
 add_library(CpuFeature::cpu_features ALIAS cpu_features)
 
diff --git a/README.md b/README.md
index ee0ce70..9e46d54 100644
--- a/README.md
+++ b/README.md
@@ -182,7 +182,7 @@ flags           : aes,avx,cx16,smx,sse4_1,sse4_2,ssse3
 |---------|:----:|:-------:|:-------:|:-------:|:-------:|:-------:|:-------:|
 | Linux   | yes² | yes¹    | yes¹    | yes¹    | yes¹    | yes¹    | yes¹    |
 | FreeBSD | yes² | not yet | not yet | not yet | not yet | N/A     | not yet |
-| MacOs   | yes² | not yet | N/A     | N/A     | no      | N/A     | no      |
+| MacOs   | yes² | yes⁵    | N/A     | N/A     | N/A     | N/A     | N/A     |
 | Windows | yes² | not yet | not yet | N/A     | N/A     | N/A     | N/A     |
 | Android | yes² | yes¹    | yes¹    | yes¹    | N/A     | N/A     | N/A     |
 | iOS     | N/A  | not yet | not yet | N/A     | N/A     | N/A     | N/A     |
@@ -200,6 +200,8 @@ flags           : aes,avx,cx16,smx,sse4_1,sse4_2,ssse3
     microarchitecture allows the client to reject particular microarchitectures.
 4.  All flavors of Mips are supported, little and big endian as well as 32/64
     bits.
+5.  **Features revealed from sysctl.** features are retrieved by the `sysctl`
+    instruction.
 
 <a name="ndk"></a>
 ## Android NDK's drop in replacement
diff --git a/src/impl_aarch64__base_implementation.inl b/src/impl_aarch64__base_implementation.inl
new file mode 100644
index 0000000..ccc6c11
--- /dev/null
+++ b/src/impl_aarch64__base_implementation.inl
@@ -0,0 +1,118 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License 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 <stdbool.h>
+
+#include "cpu_features_macros.h"
+#include "cpuinfo_aarch64.h"
+#include "internal/bit_utils.h"
+#include "internal/filesystem.h"
+#include "internal/stack_line_reader.h"
+#include "internal/string_view.h"
+
+#if !defined(CPU_FEATURES_ARCH_AARCH64)
+#error "Cannot compile aarch64_base on a non aarch64 platform."
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+// Definitions for introspection.
+////////////////////////////////////////////////////////////////////////////////
+#define INTROSPECTION_TABLE                                                  \
+  LINE(AARCH64_FP, fp, "fp", AARCH64_HWCAP_FP, 0)                            \
+  LINE(AARCH64_ASIMD, asimd, "asimd", AARCH64_HWCAP_ASIMD, 0)                \
+  LINE(AARCH64_EVTSTRM, evtstrm, "evtstrm", AARCH64_HWCAP_EVTSTRM, 0)        \
+  LINE(AARCH64_AES, aes, "aes", AARCH64_HWCAP_AES, 0)                        \
+  LINE(AARCH64_PMULL, pmull, "pmull", AARCH64_HWCAP_PMULL, 0)                \
+  LINE(AARCH64_SHA1, sha1, "sha1", AARCH64_HWCAP_SHA1, 0)                    \
+  LINE(AARCH64_SHA2, sha2, "sha2", AARCH64_HWCAP_SHA2, 0)                    \
+  LINE(AARCH64_CRC32, crc32, "crc32", AARCH64_HWCAP_CRC32, 0)                \
+  LINE(AARCH64_ATOMICS, atomics, "atomics", AARCH64_HWCAP_ATOMICS, 0)        \
+  LINE(AARCH64_FPHP, fphp, "fphp", AARCH64_HWCAP_FPHP, 0)                    \
+  LINE(AARCH64_ASIMDHP, asimdhp, "asimdhp", AARCH64_HWCAP_ASIMDHP, 0)        \
+  LINE(AARCH64_CPUID, cpuid, "cpuid", AARCH64_HWCAP_CPUID, 0)                \
+  LINE(AARCH64_ASIMDRDM, asimdrdm, "asimdrdm", AARCH64_HWCAP_ASIMDRDM, 0)    \
+  LINE(AARCH64_JSCVT, jscvt, "jscvt", AARCH64_HWCAP_JSCVT, 0)                \
+  LINE(AARCH64_FCMA, fcma, "fcma", AARCH64_HWCAP_FCMA, 0)                    \
+  LINE(AARCH64_LRCPC, lrcpc, "lrcpc", AARCH64_HWCAP_LRCPC, 0)                \
+  LINE(AARCH64_DCPOP, dcpop, "dcpop", AARCH64_HWCAP_DCPOP, 0)                \
+  LINE(AARCH64_SHA3, sha3, "sha3", AARCH64_HWCAP_SHA3, 0)                    \
+  LINE(AARCH64_SM3, sm3, "sm3", AARCH64_HWCAP_SM3, 0)                        \
+  LINE(AARCH64_SM4, sm4, "sm4", AARCH64_HWCAP_SM4, 0)                        \
+  LINE(AARCH64_ASIMDDP, asimddp, "asimddp", AARCH64_HWCAP_ASIMDDP, 0)        \
+  LINE(AARCH64_SHA512, sha512, "sha512", AARCH64_HWCAP_SHA512, 0)            \
+  LINE(AARCH64_SVE, sve, "sve", AARCH64_HWCAP_SVE, 0)                        \
+  LINE(AARCH64_ASIMDFHM, asimdfhm, "asimdfhm", AARCH64_HWCAP_ASIMDFHM, 0)    \
+  LINE(AARCH64_DIT, dit, "dit", AARCH64_HWCAP_DIT, 0)                        \
+  LINE(AARCH64_USCAT, uscat, "uscat", AARCH64_HWCAP_USCAT, 0)                \
+  LINE(AARCH64_ILRCPC, ilrcpc, "ilrcpc", AARCH64_HWCAP_ILRCPC, 0)            \
+  LINE(AARCH64_FLAGM, flagm, "flagm", AARCH64_HWCAP_FLAGM, 0)                \
+  LINE(AARCH64_SSBS, ssbs, "ssbs", AARCH64_HWCAP_SSBS, 0)                    \
+  LINE(AARCH64_SB, sb, "sb", AARCH64_HWCAP_SB, 0)                            \
+  LINE(AARCH64_PACA, paca, "paca", AARCH64_HWCAP_PACA, 0)                    \
+  LINE(AARCH64_PACG, pacg, "pacg", AARCH64_HWCAP_PACG, 0)                    \
+  LINE(AARCH64_DCPODP, dcpodp, "dcpodp", 0, AARCH64_HWCAP2_DCPODP)           \
+  LINE(AARCH64_SVE2, sve2, "sve2", 0, AARCH64_HWCAP2_SVE2)                   \
+  LINE(AARCH64_SVEAES, sveaes, "sveaes", 0, AARCH64_HWCAP2_SVEAES)           \
+  LINE(AARCH64_SVEPMULL, svepmull, "svepmull", 0, AARCH64_HWCAP2_SVEPMULL)   \
+  LINE(AARCH64_SVEBITPERM, svebitperm, "svebitperm", 0,                      \
+       AARCH64_HWCAP2_SVEBITPERM)                                            \
+  LINE(AARCH64_SVESHA3, svesha3, "svesha3", 0, AARCH64_HWCAP2_SVESHA3)       \
+  LINE(AARCH64_SVESM4, svesm4, "svesm4", 0, AARCH64_HWCAP2_SVESM4)           \
+  LINE(AARCH64_FLAGM2, flagm2, "flagm2", 0, AARCH64_HWCAP2_FLAGM2)           \
+  LINE(AARCH64_FRINT, frint, "frint", 0, AARCH64_HWCAP2_FRINT)               \
+  LINE(AARCH64_SVEI8MM, svei8mm, "svei8mm", 0, AARCH64_HWCAP2_SVEI8MM)       \
+  LINE(AARCH64_SVEF32MM, svef32mm, "svef32mm", 0, AARCH64_HWCAP2_SVEF32MM)   \
+  LINE(AARCH64_SVEF64MM, svef64mm, "svef64mm", 0, AARCH64_HWCAP2_SVEF64MM)   \
+  LINE(AARCH64_SVEBF16, svebf16, "svebf16", 0, AARCH64_HWCAP2_SVEBF16)       \
+  LINE(AARCH64_I8MM, i8mm, "i8mm", 0, AARCH64_HWCAP2_I8MM)                   \
+  LINE(AARCH64_BF16, bf16, "bf16", 0, AARCH64_HWCAP2_BF16)                   \
+  LINE(AARCH64_DGH, dgh, "dgh", 0, AARCH64_HWCAP2_DGH)                       \
+  LINE(AARCH64_RNG, rng, "rng", 0, AARCH64_HWCAP2_RNG)                       \
+  LINE(AARCH64_BTI, bti, "bti", 0, AARCH64_HWCAP2_BTI)                       \
+  LINE(AARCH64_MTE, mte, "mte", 0, AARCH64_HWCAP2_MTE)                       \
+  LINE(AARCH64_ECV, ecv, "ecv", 0, AARCH64_HWCAP2_ECV)                       \
+  LINE(AARCH64_AFP, afp, "afp", 0, AARCH64_HWCAP2_AFP)                       \
+  LINE(AARCH64_RPRES, rpres, "rpres", 0, AARCH64_HWCAP2_RPRES)               \
+  LINE(AARCH64_MTE3, mte3, "mte3", 0, AARCH64_HWCAP2_MTE3)                   \
+  LINE(AARCH64_SME, sme, "sme", 0, AARCH64_HWCAP2_SME)                       \
+  LINE(AARCH64_SME_I16I64, smei16i64, "smei16i64", 0,                        \
+       AARCH64_HWCAP2_SME_I16I64)                                            \
+  LINE(AARCH64_SME_F64F64, smef64f64, "smef64f64", 0,                        \
+       AARCH64_HWCAP2_SME_F64F64)                                            \
+  LINE(AARCH64_SME_I8I32, smei8i32, "smei8i32", 0, AARCH64_HWCAP2_SME_I8I32) \
+  LINE(AARCH64_SME_F16F32, smef16f32, "smef16f32", 0,                        \
+       AARCH64_HWCAP2_SME_F16F32)                                            \
+  LINE(AARCH64_SME_B16F32, smeb16f32, "smeb16f32", 0,                        \
+       AARCH64_HWCAP2_SME_B16F32)                                            \
+  LINE(AARCH64_SME_F32F32, smef32f32, "smef32f32", 0,                        \
+       AARCH64_HWCAP2_SME_F32F32)                                            \
+  LINE(AARCH64_SME_FA64, smefa64, "smefa64", 0, AARCH64_HWCAP2_SME_FA64)     \
+  LINE(AARCH64_WFXT, wfxt, "wfxt", 0, AARCH64_HWCAP2_WFXT)                   \
+  LINE(AARCH64_EBF16, ebf16, "ebf16", 0, AARCH64_HWCAP2_EBF16)               \
+  LINE(AARCH64_SVE_EBF16, sveebf16, "sveebf16", 0, AARCH64_HWCAP2_SVE_EBF16) \
+  LINE(AARCH64_CSSC, cssc, "cssc", 0, AARCH64_HWCAP2_CSSC)                   \
+  LINE(AARCH64_RPRFM, rprfm, "rprfm", 0, AARCH64_HWCAP2_RPRFM)               \
+  LINE(AARCH64_SVE2P1, sve2p1, "sve2p1", 0, AARCH64_HWCAP2_SVE2P1)           \
+  LINE(AARCH64_SME2, sme2, "sme2", 0, AARCH64_HWCAP2_SME2)                   \
+  LINE(AARCH64_SME2P1, sme2p1, "sme2p1", 0, AARCH64_HWCAP2_SME2P1)           \
+  LINE(AARCH64_SME_I16I32, smei16i32, "smei16i32", 0,                        \
+       AARCH64_HWCAP2_SME_I16I32)                                            \
+  LINE(AARCH64_SME_BI32I32, smebi32i32, "smebi32i32", 0,                     \
+       AARCH64_HWCAP2_SME_BI32I32)                                           \
+  LINE(AARCH64_SME_B16B16, smeb16b16, "smeb16b16", 0,                        \
+       AARCH64_HWCAP2_SME_B16B16)                                            \
+  LINE(AARCH64_SME_F16F16, smef16f16, "smef16f16", 0, AARCH64_HWCAP2_SME_F16F16)
+#define INTROSPECTION_PREFIX Aarch64
+#define INTROSPECTION_ENUM_PREFIX AARCH64
+#include "define_introspection_and_hwcaps.inl"
diff --git a/src/impl_aarch64_linux_or_android.c b/src/impl_aarch64_linux_or_android.c
index f06a52f..c0a764c 100644
--- a/src/impl_aarch64_linux_or_android.c
+++ b/src/impl_aarch64_linux_or_android.c
@@ -17,110 +17,7 @@
 #ifdef CPU_FEATURES_ARCH_AARCH64
 #if defined(CPU_FEATURES_OS_LINUX) || defined(CPU_FEATURES_OS_ANDROID)
 
-#include "cpuinfo_aarch64.h"
-
-////////////////////////////////////////////////////////////////////////////////
-// Definitions for introspection.
-////////////////////////////////////////////////////////////////////////////////
-#define INTROSPECTION_TABLE                                                  \
-  LINE(AARCH64_FP, fp, "fp", AARCH64_HWCAP_FP, 0)                            \
-  LINE(AARCH64_ASIMD, asimd, "asimd", AARCH64_HWCAP_ASIMD, 0)                \
-  LINE(AARCH64_EVTSTRM, evtstrm, "evtstrm", AARCH64_HWCAP_EVTSTRM, 0)        \
-  LINE(AARCH64_AES, aes, "aes", AARCH64_HWCAP_AES, 0)                        \
-  LINE(AARCH64_PMULL, pmull, "pmull", AARCH64_HWCAP_PMULL, 0)                \
-  LINE(AARCH64_SHA1, sha1, "sha1", AARCH64_HWCAP_SHA1, 0)                    \
-  LINE(AARCH64_SHA2, sha2, "sha2", AARCH64_HWCAP_SHA2, 0)                    \
-  LINE(AARCH64_CRC32, crc32, "crc32", AARCH64_HWCAP_CRC32, 0)                \
-  LINE(AARCH64_ATOMICS, atomics, "atomics", AARCH64_HWCAP_ATOMICS, 0)        \
-  LINE(AARCH64_FPHP, fphp, "fphp", AARCH64_HWCAP_FPHP, 0)                    \
-  LINE(AARCH64_ASIMDHP, asimdhp, "asimdhp", AARCH64_HWCAP_ASIMDHP, 0)        \
-  LINE(AARCH64_CPUID, cpuid, "cpuid", AARCH64_HWCAP_CPUID, 0)                \
-  LINE(AARCH64_ASIMDRDM, asimdrdm, "asimdrdm", AARCH64_HWCAP_ASIMDRDM, 0)    \
-  LINE(AARCH64_JSCVT, jscvt, "jscvt", AARCH64_HWCAP_JSCVT, 0)                \
-  LINE(AARCH64_FCMA, fcma, "fcma", AARCH64_HWCAP_FCMA, 0)                    \
-  LINE(AARCH64_LRCPC, lrcpc, "lrcpc", AARCH64_HWCAP_LRCPC, 0)                \
-  LINE(AARCH64_DCPOP, dcpop, "dcpop", AARCH64_HWCAP_DCPOP, 0)                \
-  LINE(AARCH64_SHA3, sha3, "sha3", AARCH64_HWCAP_SHA3, 0)                    \
-  LINE(AARCH64_SM3, sm3, "sm3", AARCH64_HWCAP_SM3, 0)                        \
-  LINE(AARCH64_SM4, sm4, "sm4", AARCH64_HWCAP_SM4, 0)                        \
-  LINE(AARCH64_ASIMDDP, asimddp, "asimddp", AARCH64_HWCAP_ASIMDDP, 0)        \
-  LINE(AARCH64_SHA512, sha512, "sha512", AARCH64_HWCAP_SHA512, 0)            \
-  LINE(AARCH64_SVE, sve, "sve", AARCH64_HWCAP_SVE, 0)                        \
-  LINE(AARCH64_ASIMDFHM, asimdfhm, "asimdfhm", AARCH64_HWCAP_ASIMDFHM, 0)    \
-  LINE(AARCH64_DIT, dit, "dit", AARCH64_HWCAP_DIT, 0)                        \
-  LINE(AARCH64_USCAT, uscat, "uscat", AARCH64_HWCAP_USCAT, 0)                \
-  LINE(AARCH64_ILRCPC, ilrcpc, "ilrcpc", AARCH64_HWCAP_ILRCPC, 0)            \
-  LINE(AARCH64_FLAGM, flagm, "flagm", AARCH64_HWCAP_FLAGM, 0)                \
-  LINE(AARCH64_SSBS, ssbs, "ssbs", AARCH64_HWCAP_SSBS, 0)                    \
-  LINE(AARCH64_SB, sb, "sb", AARCH64_HWCAP_SB, 0)                            \
-  LINE(AARCH64_PACA, paca, "paca", AARCH64_HWCAP_PACA, 0)                    \
-  LINE(AARCH64_PACG, pacg, "pacg", AARCH64_HWCAP_PACG, 0)                    \
-  LINE(AARCH64_DCPODP, dcpodp, "dcpodp", 0, AARCH64_HWCAP2_DCPODP)           \
-  LINE(AARCH64_SVE2, sve2, "sve2", 0, AARCH64_HWCAP2_SVE2)                   \
-  LINE(AARCH64_SVEAES, sveaes, "sveaes", 0, AARCH64_HWCAP2_SVEAES)           \
-  LINE(AARCH64_SVEPMULL, svepmull, "svepmull", 0, AARCH64_HWCAP2_SVEPMULL)   \
-  LINE(AARCH64_SVEBITPERM, svebitperm, "svebitperm", 0,                      \
-       AARCH64_HWCAP2_SVEBITPERM)                                            \
-  LINE(AARCH64_SVESHA3, svesha3, "svesha3", 0, AARCH64_HWCAP2_SVESHA3)       \
-  LINE(AARCH64_SVESM4, svesm4, "svesm4", 0, AARCH64_HWCAP2_SVESM4)           \
-  LINE(AARCH64_FLAGM2, flagm2, "flagm2", 0, AARCH64_HWCAP2_FLAGM2)           \
-  LINE(AARCH64_FRINT, frint, "frint", 0, AARCH64_HWCAP2_FRINT)               \
-  LINE(AARCH64_SVEI8MM, svei8mm, "svei8mm", 0, AARCH64_HWCAP2_SVEI8MM)       \
-  LINE(AARCH64_SVEF32MM, svef32mm, "svef32mm", 0, AARCH64_HWCAP2_SVEF32MM)   \
-  LINE(AARCH64_SVEF64MM, svef64mm, "svef64mm", 0, AARCH64_HWCAP2_SVEF64MM)   \
-  LINE(AARCH64_SVEBF16, svebf16, "svebf16", 0, AARCH64_HWCAP2_SVEBF16)       \
-  LINE(AARCH64_I8MM, i8mm, "i8mm", 0, AARCH64_HWCAP2_I8MM)                   \
-  LINE(AARCH64_BF16, bf16, "bf16", 0, AARCH64_HWCAP2_BF16)                   \
-  LINE(AARCH64_DGH, dgh, "dgh", 0, AARCH64_HWCAP2_DGH)                       \
-  LINE(AARCH64_RNG, rng, "rng", 0, AARCH64_HWCAP2_RNG)                       \
-  LINE(AARCH64_BTI, bti, "bti", 0, AARCH64_HWCAP2_BTI)                       \
-  LINE(AARCH64_MTE, mte, "mte", 0, AARCH64_HWCAP2_MTE)                       \
-  LINE(AARCH64_ECV, ecv, "ecv", 0, AARCH64_HWCAP2_ECV)                       \
-  LINE(AARCH64_AFP, afp, "afp", 0, AARCH64_HWCAP2_AFP)                       \
-  LINE(AARCH64_RPRES, rpres, "rpres", 0, AARCH64_HWCAP2_RPRES)               \
-  LINE(AARCH64_MTE3, mte3, "mte3", 0, AARCH64_HWCAP2_MTE3)                   \
-  LINE(AARCH64_SME, sme, "sme", 0, AARCH64_HWCAP2_SME)                       \
-  LINE(AARCH64_SME_I16I64, smei16i64, "smei16i64", 0,                        \
-       AARCH64_HWCAP2_SME_I16I64)                                            \
-  LINE(AARCH64_SME_F64F64, smef64f64, "smef64f64", 0,                        \
-       AARCH64_HWCAP2_SME_F64F64)                                            \
-  LINE(AARCH64_SME_I8I32, smei8i32, "smei8i32", 0, AARCH64_HWCAP2_SME_I8I32) \
-  LINE(AARCH64_SME_F16F32, smef16f32, "smef16f32", 0,                        \
-       AARCH64_HWCAP2_SME_F16F32)                                            \
-  LINE(AARCH64_SME_B16F32, smeb16f32, "smeb16f32", 0,                        \
-       AARCH64_HWCAP2_SME_B16F32)                                            \
-  LINE(AARCH64_SME_F32F32, smef32f32, "smef32f32", 0,                        \
-       AARCH64_HWCAP2_SME_F32F32)                                            \
-  LINE(AARCH64_SME_FA64, smefa64, "smefa64", 0, AARCH64_HWCAP2_SME_FA64)     \
-  LINE(AARCH64_WFXT, wfxt, "wfxt", 0, AARCH64_HWCAP2_WFXT)                   \
-  LINE(AARCH64_EBF16, ebf16, "ebf16", 0, AARCH64_HWCAP2_EBF16)               \
-  LINE(AARCH64_SVE_EBF16, sveebf16, "sveebf16", 0, AARCH64_HWCAP2_SVE_EBF16) \
-  LINE(AARCH64_CSSC, cssc, "cssc", 0, AARCH64_HWCAP2_CSSC)                   \
-  LINE(AARCH64_RPRFM, rprfm, "rprfm", 0, AARCH64_HWCAP2_RPRFM)               \
-  LINE(AARCH64_SVE2P1, sve2p1, "sve2p1", 0, AARCH64_HWCAP2_SVE2P1)           \
-  LINE(AARCH64_SME2, sme2, "sme2", 0, AARCH64_HWCAP2_SME2)                   \
-  LINE(AARCH64_SME2P1, sme2p1, "sme2p1", 0, AARCH64_HWCAP2_SME2P1)           \
-  LINE(AARCH64_SME_I16I32, smei16i32, "smei16i32", 0,                        \
-       AARCH64_HWCAP2_SME_I16I32)                                            \
-  LINE(AARCH64_SME_BI32I32, smebi32i32, "smebi32i32", 0,                     \
-       AARCH64_HWCAP2_SME_BI32I32)                                           \
-  LINE(AARCH64_SME_B16B16, smeb16b16, "smeb16b16", 0,                        \
-       AARCH64_HWCAP2_SME_B16B16)                                            \
-  LINE(AARCH64_SME_F16F16, smef16f16, "smef16f16", 0, AARCH64_HWCAP2_SME_F16F16)
-#define INTROSPECTION_PREFIX Aarch64
-#define INTROSPECTION_ENUM_PREFIX AARCH64
-#include "define_introspection_and_hwcaps.inl"
-
-////////////////////////////////////////////////////////////////////////////////
-// Implementation.
-////////////////////////////////////////////////////////////////////////////////
-
-#include <stdbool.h>
-
-#include "internal/bit_utils.h"
-#include "internal/filesystem.h"
-#include "internal/stack_line_reader.h"
-#include "internal/string_view.h"
+#include "impl_aarch64__base_implementation.inl"
 
 static bool HandleAarch64Line(const LineResult result,
                               Aarch64Info* const info) {
diff --git a/src/impl_aarch64_macos_or_iphone.c b/src/impl_aarch64_macos_or_iphone.c
new file mode 100644
index 0000000..7b97896
--- /dev/null
+++ b/src/impl_aarch64_macos_or_iphone.c
@@ -0,0 +1,88 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License 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 "cpu_features_macros.h"
+
+#ifdef CPU_FEATURES_ARCH_AARCH64
+#if defined(CPU_FEATURES_OS_MACOS) || defined(CPU_FEATURES_OS_IPHONE)
+
+#include "impl_aarch64__base_implementation.inl"
+
+#if !defined(HAVE_SYSCTLBYNAME)
+#error "Darwin needs support for sysctlbyname"
+#endif
+#include <sys/sysctl.h>
+
+#if defined(CPU_FEATURES_MOCK_SYSCTL_AARCH64)
+extern bool GetDarwinSysCtlByName(const char*);
+extern int GetDarwinSysCtlByNameValue(const char* name);
+#else
+static int GetDarwinSysCtlByNameValue(const char* name) {
+  int enabled;
+  size_t enabled_len = sizeof(enabled);
+  const int failure = sysctlbyname(name, &enabled, &enabled_len, NULL, 0);
+  return failure ? 0 : enabled;
+}
+
+static bool GetDarwinSysCtlByName(const char* name) {
+  return GetDarwinSysCtlByNameValue(name) != 0;
+}
+#endif
+
+static const Aarch64Info kEmptyAarch64Info;
+
+Aarch64Info GetAarch64Info(void) {
+  Aarch64Info info = kEmptyAarch64Info;
+
+  // Handling Darwin platform through sysctlbyname.
+  info.implementer = GetDarwinSysCtlByNameValue("hw.cputype");
+  info.variant = GetDarwinSysCtlByNameValue("hw.cpusubtype");
+  info.part = GetDarwinSysCtlByNameValue("hw.cpufamily");
+  info.revision = GetDarwinSysCtlByNameValue("hw.cpusubfamily");
+
+  info.features.fp = GetDarwinSysCtlByName("hw.optional.floatingpoint");
+  info.features.asimd = GetDarwinSysCtlByName("hw.optional.AdvSIMD");
+  info.features.aes = GetDarwinSysCtlByName("hw.optional.arm.FEAT_AES");
+  info.features.pmull = GetDarwinSysCtlByName("hw.optional.arm.FEAT_PMULL");
+  info.features.sha1 = GetDarwinSysCtlByName("hw.optional.arm.FEAT_SHA1");
+  info.features.sha2 = GetDarwinSysCtlByName("hw.optional.arm.FEAT_SHA256");
+  info.features.crc32 = GetDarwinSysCtlByName("hw.optional.armv8_crc32");
+  info.features.atomics = GetDarwinSysCtlByName("hw.optional.arm.FEAT_LSE");
+  info.features.fphp = GetDarwinSysCtlByName("hw.optional.arm.FEAT_FP16");
+  info.features.asimdhp = GetDarwinSysCtlByName("hw.optional.arm.AdvSIMD_HPFPCvt");
+  info.features.asimdrdm = GetDarwinSysCtlByName("hw.optional.arm.FEAT_RDM");
+  info.features.jscvt = GetDarwinSysCtlByName("hw.optional.arm.FEAT_JSCVT");
+  info.features.fcma = GetDarwinSysCtlByName("hw.optional.arm.FEAT_FCMA");
+  info.features.lrcpc = GetDarwinSysCtlByName("hw.optional.arm.FEAT_LRCPC");
+  info.features.dcpop = GetDarwinSysCtlByName("hw.optional.arm.FEAT_DPB");
+  info.features.sha3 = GetDarwinSysCtlByName("hw.optional.arm.FEAT_SHA3");
+  info.features.asimddp = GetDarwinSysCtlByName("hw.optional.arm.FEAT_DotProd");
+  info.features.sha512 = GetDarwinSysCtlByName("hw.optional.arm.FEAT_SHA512");
+  info.features.asimdfhm = GetDarwinSysCtlByName("hw.optional.arm.FEAT_FHM");
+  info.features.dit = GetDarwinSysCtlByName("hw.optional.arm.FEAT_DIT");
+  info.features.uscat = GetDarwinSysCtlByName("hw.optional.arm.FEAT_LSE2");
+  info.features.flagm = GetDarwinSysCtlByName("hw.optional.arm.FEAT_FlagM");
+  info.features.ssbs = GetDarwinSysCtlByName("hw.optional.arm.FEAT_SSBS");
+  info.features.sb = GetDarwinSysCtlByName("hw.optional.arm.FEAT_SB");
+  info.features.flagm2 = GetDarwinSysCtlByName("hw.optional.arm.FEAT_FlagM2");
+  info.features.frint = GetDarwinSysCtlByName("hw.optional.arm.FEAT_FRINTTS");
+  info.features.i8mm = GetDarwinSysCtlByName("hw.optional.arm.FEAT_I8MM");
+  info.features.bf16 = GetDarwinSysCtlByName("hw.optional.arm.FEAT_BF16");
+  info.features.bti = GetDarwinSysCtlByName("hw.optional.arm.FEAT_BTI");
+
+  return info;
+}
+
+#endif  // defined(CPU_FEATURES_OS_MACOS) || defined(CPU_FEATURES_OS_IPHONE)
+#endif  // CPU_FEATURES_ARCH_AARCH64
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 97efdde..f21ff98 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -74,8 +74,15 @@ if(PROCESSOR_IS_AARCH64)
   add_executable(cpuinfo_aarch64_test
     cpuinfo_aarch64_test.cc
     ../src/impl_aarch64_linux_or_android.c
-    ../src/impl_aarch64_windows.c)
-  target_compile_definitions(cpuinfo_aarch64_test PUBLIC CPU_FEATURES_MOCK_CPUID_AARCH64)
+    ../src/impl_aarch64_windows.c
+    ../src/impl_aarch64_macos_or_iphone.c
+  )
+  if(APPLE)
+    target_compile_definitions(cpuinfo_aarch64_test PUBLIC CPU_FEATURES_MOCK_SYSCTL_AARCH64)
+    target_compile_definitions(cpuinfo_aarch64_test PRIVATE HAVE_SYSCTLBYNAME)
+  else()
+    target_compile_definitions(cpuinfo_aarch64_test PUBLIC CPU_FEATURES_MOCK_CPUID_AARCH64)
+  endif()
   target_link_libraries(cpuinfo_aarch64_test all_libraries)
   add_test(NAME cpuinfo_aarch64_test COMMAND cpuinfo_aarch64_test)
 endif()
diff --git a/test/cpuinfo_aarch64_test.cc b/test/cpuinfo_aarch64_test.cc
index e32367a..1305381 100644
--- a/test/cpuinfo_aarch64_test.cc
+++ b/test/cpuinfo_aarch64_test.cc
@@ -25,8 +25,35 @@
 
 namespace cpu_features {
 class FakeCpuAarch64 {
+#if defined(CPU_FEATURES_OS_LINUX)
+  // No particular implementation for Linux as we use /proc/cpuinfo
+#elif defined(CPU_FEATURES_OS_MACOS)
+  std::set<std::string> darwin_sysctlbyname_;
+  std::map<std::string, int> darwin_sysctlbynamevalue_;
+
+ public:
+  bool GetDarwinSysCtlByName(std::string name) const {
+    return darwin_sysctlbyname_.count(name);
+  }
+
+  int GetDarwinSysCtlByNameValue(std::string name) const {
+    const auto iter = darwin_sysctlbynamevalue_.find(name);
+    if (iter != darwin_sysctlbynamevalue_.end()) return iter->second;
+    return 0;
+  }
+
+  void SetDarwinSysCtlByName(std::string name) {
+    darwin_sysctlbyname_.insert(name);
+  }
+
+  void SetDarwinSysCtlByNameValue(std::string name, int value) {
+    darwin_sysctlbynamevalue_[name] = value;
+  }
+#elif defined(CPU_FEATURES_OS_WINDOWS)
+  std::set<DWORD> windows_isprocessorfeaturepresent_;
+  WORD processor_revision_{};
+
  public:
-#if defined(CPU_FEATURES_OS_WINDOWS)
   bool GetWindowsIsProcessorFeaturePresent(DWORD dwProcessorFeature) {
     return windows_isprocessorfeaturepresent_.count(dwProcessorFeature);
   }
@@ -42,11 +69,7 @@ class FakeCpuAarch64 {
   void SetWindowsNativeSystemInfoProcessorRevision(WORD wProcessorRevision) {
     processor_revision_ = wProcessorRevision;
   }
-
- private:
-  std::set<DWORD> windows_isprocessorfeaturepresent_;
-  WORD processor_revision_{};
-#endif  // CPU_FEATURES_OS_WINDOWS
+#endif
 };
 
 static FakeCpuAarch64* g_fake_cpu_instance = nullptr;
@@ -56,7 +79,18 @@ static FakeCpuAarch64& cpu() {
   return *g_fake_cpu_instance;
 }
 
-#if defined(CPU_FEATURES_OS_WINDOWS)
+// Define OS dependent mock functions
+#if defined(CPU_FEATURES_OS_LINUX)
+// No particular functions to implement for Linux as we use /proc/cpuinfo
+#elif defined(CPU_FEATURES_OS_MACOS)
+extern "C" bool GetDarwinSysCtlByName(const char* name) {
+  return cpu().GetDarwinSysCtlByName(name);
+}
+
+extern "C" int GetDarwinSysCtlByNameValue(const char* name) {
+  return cpu().GetDarwinSysCtlByNameValue(name);
+}
+#elif defined(CPU_FEATURES_OS_WINDOWS)
 extern "C" bool GetWindowsIsProcessorFeaturePresent(DWORD dwProcessorFeature) {
   return cpu().GetWindowsIsProcessorFeaturePresent(dwProcessorFeature);
 }
@@ -64,7 +98,7 @@ extern "C" bool GetWindowsIsProcessorFeaturePresent(DWORD dwProcessorFeature) {
 extern "C" WORD GetWindowsNativeSystemInfoProcessorRevision() {
   return cpu().GetWindowsNativeSystemInfoProcessorRevision();
 }
-#endif  // CPU_FEATURES_OS_WINDOWS
+#endif
 
 namespace {
 
@@ -80,7 +114,7 @@ class CpuidAarch64Test : public ::testing::Test {
   }
 };
 
-TEST(CpuinfoAarch64Test, Aarch64FeaturesEnum) {
+TEST_F(CpuidAarch64Test, Aarch64FeaturesEnum) {
   const char* last_name = GetAarch64FeaturesEnumName(AARCH64_LAST_);
   EXPECT_STREQ(last_name, "unknown_feature");
   for (int i = static_cast<int>(AARCH64_FP);
@@ -93,10 +127,11 @@ TEST(CpuinfoAarch64Test, Aarch64FeaturesEnum) {
   }
 }
 
+// OS dependent tests
 #if defined(CPU_FEATURES_OS_LINUX)
 void DisableHardwareCapabilities() { SetHardwareCapabilities(0, 0); }
 
-TEST(CpuinfoAarch64Test, FromHardwareCap) {
+TEST_F(CpuidAarch64Test, FromHardwareCap) {
   ResetHwcaps();
   SetHardwareCapabilities(AARCH64_HWCAP_FP | AARCH64_HWCAP_AES, 0);
   GetEmptyFilesystem();  // disabling /proc/cpuinfo
@@ -135,7 +170,7 @@ TEST(CpuinfoAarch64Test, FromHardwareCap) {
   EXPECT_FALSE(info.features.pacg);
 }
 
-TEST(CpuinfoAarch64Test, FromHardwareCap2) {
+TEST_F(CpuidAarch64Test, FromHardwareCap2) {
   ResetHwcaps();
   SetHardwareCapabilities(AARCH64_HWCAP_FP,
                           AARCH64_HWCAP2_SVE2 | AARCH64_HWCAP2_BTI);
@@ -164,7 +199,7 @@ TEST(CpuinfoAarch64Test, FromHardwareCap2) {
   EXPECT_FALSE(info.features.rng);
 }
 
-TEST(CpuinfoAarch64Test, ARMCortexA53) {
+TEST_F(CpuidAarch64Test, ARMCortexA53) {
   ResetHwcaps();
   auto& fs = GetEmptyFilesystem();
   fs.CreateFile("/proc/cpuinfo",
@@ -266,9 +301,68 @@ CPU revision    : 3)");
   EXPECT_FALSE(info.features.smeb16b16);
   EXPECT_FALSE(info.features.smef16f16);
 }
-#endif  // CPU_FEATURES_OS_LINUX
+#elif defined(CPU_FEATURES_OS_MACOS)
+TEST_F(CpuidAarch64Test, FromDarwinSysctlFromName) {
+  cpu().SetDarwinSysCtlByName("hw.optional.floatingpoint");
+  cpu().SetDarwinSysCtlByName("hw.optional.neon");
+  cpu().SetDarwinSysCtlByName("hw.optional.AdvSIMD_HPFPCvt");
+  cpu().SetDarwinSysCtlByName("hw.optional.arm.FEAT_FP16");
+  cpu().SetDarwinSysCtlByName("hw.optional.arm.FEAT_LSE");
+  cpu().SetDarwinSysCtlByName("hw.optional.armv8_crc32");
+  cpu().SetDarwinSysCtlByName("hw.optional.arm.FEAT_FHM");
+  cpu().SetDarwinSysCtlByName("hw.optional.arm.FEAT_SHA512");
+  cpu().SetDarwinSysCtlByName("hw.optional.arm.FEAT_SHA3");
+  cpu().SetDarwinSysCtlByName("hw.optional.amx_version");
+  cpu().SetDarwinSysCtlByName("hw.optional.ucnormal_mem");
+  cpu().SetDarwinSysCtlByName("hw.optional.arm64");
 
-#if defined(CPU_FEATURES_OS_WINDOWS)
+  cpu().SetDarwinSysCtlByNameValue("hw.cputype", 16777228);
+  cpu().SetDarwinSysCtlByNameValue("hw.cpusubtype", 2);
+  cpu().SetDarwinSysCtlByNameValue("hw.cpu64bit", 1);
+  cpu().SetDarwinSysCtlByNameValue("hw.cpufamily", 458787763);
+  cpu().SetDarwinSysCtlByNameValue("hw.cpusubfamily", 2);
+
+  const auto info = GetAarch64Info();
+
+  EXPECT_EQ(info.implementer, 0x100000C);
+  EXPECT_EQ(info.variant, 2);
+  EXPECT_EQ(info.part, 0x1B588BB3);
+  EXPECT_EQ(info.revision, 2);
+
+  EXPECT_TRUE(info.features.fp);
+  EXPECT_FALSE(info.features.asimd);
+  EXPECT_FALSE(info.features.evtstrm);
+  EXPECT_FALSE(info.features.aes);
+  EXPECT_FALSE(info.features.pmull);
+  EXPECT_FALSE(info.features.sha1);
+  EXPECT_FALSE(info.features.sha2);
+  EXPECT_TRUE(info.features.crc32);
+  EXPECT_TRUE(info.features.atomics);
+  EXPECT_TRUE(info.features.fphp);
+  EXPECT_FALSE(info.features.asimdhp);
+  EXPECT_FALSE(info.features.cpuid);
+  EXPECT_FALSE(info.features.asimdrdm);
+  EXPECT_FALSE(info.features.jscvt);
+  EXPECT_FALSE(info.features.fcma);
+  EXPECT_FALSE(info.features.lrcpc);
+  EXPECT_FALSE(info.features.dcpop);
+  EXPECT_TRUE(info.features.sha3);
+  EXPECT_FALSE(info.features.sm3);
+  EXPECT_FALSE(info.features.sm4);
+  EXPECT_FALSE(info.features.asimddp);
+  EXPECT_TRUE(info.features.sha512);
+  EXPECT_FALSE(info.features.sve);
+  EXPECT_TRUE(info.features.asimdfhm);
+  EXPECT_FALSE(info.features.dit);
+  EXPECT_FALSE(info.features.uscat);
+  EXPECT_FALSE(info.features.ilrcpc);
+  EXPECT_FALSE(info.features.flagm);
+  EXPECT_FALSE(info.features.ssbs);
+  EXPECT_FALSE(info.features.sb);
+  EXPECT_FALSE(info.features.paca);
+  EXPECT_FALSE(info.features.pacg);
+}
+#elif defined(CPU_FEATURES_OS_WINDOWS)
 TEST_F(CpuidAarch64Test, WINDOWS_AARCH64_RPI4) {
   cpu().SetWindowsNativeSystemInfoProcessorRevision(0x03);
   cpu().SetWindowsIsProcessorFeaturePresent(PF_ARM_VFP_32_REGISTERS_AVAILABLE);
@@ -292,6 +386,5 @@ TEST_F(CpuidAarch64Test, WINDOWS_AARCH64_RPI4) {
   EXPECT_FALSE(info.features.lrcpc);
 }
 #endif  // CPU_FEATURES_OS_WINDOWS
-
 }  // namespace
 }  // namespace cpu_features