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Rollback support runtime dispatch on AArch64 macOS

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for breaking some builds

PiperOrigin-RevId: 716676691
Change-Id: Icef8b00950262b6fb0385311b9b52dcac65a0a6a
This commit is contained in:
Abseil Team
2025-01-17 08:17:37 -08:00
committed by Copybara-Service
parent b87a7955b8
commit 95049aadbe
5 changed files with 20 additions and 81 deletions
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1
absl/random/CMakeLists.txt
View File

@@ -853,7 +853,6 @@ absl_cc_library(
absl::random_internal_platform
absl::random_internal_randen_hwaes_impl
absl::config
absl::optional
)
# Internal-only target, do not depend on directly.

1
absl/random/internal/BUILD.bazel
View File

@@ -403,7 +403,6 @@ cc_library(
":platform",
":randen_hwaes_impl",
"//absl/base:config",
"//absl/types:optional",
],
)

24
absl/random/internal/platform.h
View File

@@ -12,8 +12,6 @@
// See the License for the specific language governing permissions and
// limitations under the License.
// SKIP_ABSL_INLINE_NAMESPACE_CHECK
#ifndef ABSL_RANDOM_INTERNAL_PLATFORM_H_
#define ABSL_RANDOM_INTERNAL_PLATFORM_H_
@@ -136,14 +134,7 @@
// accelerated Randen implementation.
#define ABSL_RANDOM_INTERNAL_AES_DISPATCH 0
// iOS does not support dispatch, even on x86, since applications
// should be bundled as fat binaries, with a different build tailored for
// each specific supported platform/architecture.
#if (defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) || \
(defined(TARGET_OS_IPHONE_SIMULATOR) && TARGET_OS_IPHONE_SIMULATOR)
#undef ABSL_RANDOM_INTERNAL_AES_DISPATCH
#define ABSL_RANDOM_INTERNAL_AES_DISPATCH 0
#elif defined(ABSL_ARCH_X86_64)
#if defined(ABSL_ARCH_X86_64)
// Dispatch is available on x86_64
#undef ABSL_RANDOM_INTERNAL_AES_DISPATCH
#define ABSL_RANDOM_INTERNAL_AES_DISPATCH 1
@@ -151,8 +142,8 @@
// Or when running linux PPC
#undef ABSL_RANDOM_INTERNAL_AES_DISPATCH
#define ABSL_RANDOM_INTERNAL_AES_DISPATCH 1
#elif (defined(__linux__) || defined(__APPLE__)) && defined(ABSL_ARCH_AARCH64)
// Or when running linux or macOS AArch64
#elif defined(__linux__) && defined(ABSL_ARCH_AARCH64)
// Or when running linux AArch64
#undef ABSL_RANDOM_INTERNAL_AES_DISPATCH
#define ABSL_RANDOM_INTERNAL_AES_DISPATCH 1
#elif defined(__linux__) && defined(ABSL_ARCH_ARM) && (__ARM_ARCH >= 8)
@@ -168,4 +159,13 @@
#define ABSL_RANDOM_INTERNAL_AES_DISPATCH 0
#endif
// iOS does not support dispatch, even on x86, since applications
// should be bundled as fat binaries, with a different build tailored for
// each specific supported platform/architecture.
#if (defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) || \
(defined(TARGET_OS_IPHONE_SIMULATOR) && TARGET_OS_IPHONE_SIMULATOR)
#undef ABSL_RANDOM_INTERNAL_AES_DISPATCH
#define ABSL_RANDOM_INTERNAL_AES_DISPATCH 0
#endif
#endif // ABSL_RANDOM_INTERNAL_PLATFORM_H_

73
absl/random/internal/randen_detect.cc
View File

@@ -19,21 +19,10 @@
#include "absl/random/internal/randen_detect.h"
#if defined(__APPLE__) && defined(__aarch64__)
#if defined(__has_include)
#if __has_include(<arm/cpu_capabilities_public.h>)
#include <arm/cpu_capabilities_public.h>
#endif
#endif
#include <sys/sysctl.h>
#include <sys/types.h>
#endif
#include <cstdint>
#include <cstring>
#include "absl/random/internal/platform.h"
#include "absl/types/optional.h" // IWYU pragma: keep
#if !defined(__UCLIBC__) && defined(__GLIBC__) && \
(__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 16))
@@ -113,19 +102,6 @@ static uint32_t GetAuxval(uint32_t hwcap_type) {
#endif
#if defined(__APPLE__) && defined(ABSL_ARCH_AARCH64)
template <typename T>
static absl::optional<T> ReadSysctlByName(const char* name) {
T val;
size_t val_size = sizeof(T);
int ret = sysctlbyname(name, &val, &val_size, nullptr, 0);
if (ret == -1) {
return std::nullopt;
}
return val;
}
#endif
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace random_internal {
@@ -146,18 +122,14 @@ namespace random_internal {
//
// Fon non-x86 it is much more complicated.
//
// 2. Try to use __builtin_cpu_supports.
//
// 3. When ABSL_INTERNAL_USE_GETAUXVAL is defined, use getauxval() (either
// 2. When ABSL_INTERNAL_USE_GETAUXVAL is defined, use getauxval() (either
// the direct c-library version, or the android probing version which loads
// libc), and read the hardware capability bits.
// This is based on the technique used by boringssl uses to detect
// cpu capabilities, and should allow us to enable crypto in the android
// builds where it is supported.
//
// 4. When __APPLE__ is defined on AARCH64, use sysctlbyname().
//
// 5. Use the default for the compiler architecture.
// 3. Use the default for the compiler architecture.
//
bool CPUSupportsRandenHwAes() {
@@ -167,14 +139,8 @@ bool CPUSupportsRandenHwAes() {
__cpuid(reinterpret_cast<int*>(regs), 1);
return regs[2] & (1 << 25); // AES
#elif defined(ABSL_ARCH_AARCH64) && ABSL_HAVE_BUILTIN(__builtin_cpu_supports)
// For AARCH64: Require crypto+neon
// http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0500f/CIHBIBBA.html
//
// __builtin_cpu_supports spells "crypt" as "aes" and "neon" as "simd".
return __builtin_cpu_supports("aes+simd");
#elif defined(ABSL_INTERNAL_USE_GETAUXVAL)
// 3. Use getauxval() to read the hardware bits and determine
// 2. Use getauxval() to read the hardware bits and determine
// cpu capabilities.
#define AT_HWCAP 16
@@ -212,36 +178,8 @@ bool CPUSupportsRandenHwAes() {
return ((hwcap & kNEON) != 0) && ((hwcap & kAES) != 0);
#endif
#elif defined(__APPLE__) && defined(ABSL_ARCH_AARCH64)
// 4. Use sysctlbyname.
// Newer XNU kernels support querying all capabilities in a single
// sysctlbyname.
#if defined(CAP_BIT_AdvSIMD) && defined(CAP_BIT_FEAT_AES)
static const absl::optional<uint64_t> caps =
ReadSysctlByName<uint64_t>("hw.optional.arm.caps");
if (caps.has_value()) {
constexpr uint64_t kNeonAndAesCaps =
(uint64_t{1} << CAP_BIT_AdvSIMD) | (uint64_t{1} << CAP_BIT_FEAT_AES);
return (*caps & kNeonAndAesCaps) == kNeonAndAesCaps;
}
#endif
// https://developer.apple.com/documentation/kernel/1387446-sysctlbyname/determining_instruction_set_characteristics#overview
static const absl::optional<int> adv_simd =
ReadSysctlByName<int>("hw.optional.AdvSIMD");
if (adv_simd.value_or(0) == 0) {
return false;
}
// https://developer.apple.com/documentation/kernel/1387446-sysctlbyname/determining_instruction_set_characteristics#3918855
static const absl::optional<int> feat_aes =
ReadSysctlByName<int>("hw.optional.arm.FEAT_AES");
if (feat_aes.value_or(0) == 0) {
return false;
}
return true;
#else // ABSL_INTERNAL_USE_GETAUXVAL
// 5. By default, assume that the compiler default.
// 3. By default, assume that the compiler default.
return ABSL_HAVE_ACCELERATED_AES ? true : false;
#endif
@@ -277,6 +215,9 @@ bool CPUSupportsRandenHwAes() {
// __asm __volatile("mrs %0, id_aa64isar0_el1" :"=&r" (val));
//
// * Use a CPUID-style heuristic database.
//
// * On Apple (__APPLE__), AES is available on Arm v8.
// https://stackoverflow.com/questions/45637888/how-to-determine-armv8-features-at-runtime-on-ios
}
#if defined(__clang__)

2
absl/random/internal/randen_hwaes_test.cc
View File

@@ -89,7 +89,7 @@ int main(int argc, char* argv[]) {
LOG(INFO) << "HasRandenHwAesImplementation = " << x;
int y = absl::random_internal::CPUSupportsRandenHwAes();
LOG(INFO) << "CPUSupportsRandenHwAes = " << y;
LOG(INFO) << "CPUSupportsRandenHwAes = " << x;
if (!x || !y) {
LOG(INFO) << "Skipping Randen HWAES tests.";