From 637722af3a60c17915d3325604a0435ee92a41b4 Mon Sep 17 00:00:00 2001 From: Abseil Team Date: Wed, 25 Aug 2021 12:02:10 -0700 Subject: Export of internal Abseil changes -- e1c30aa6d6bb25987916d3ec39245c6d4a2a93ea by Derek Mauro : Only build the non-stub implementation of RandenHwAes when accelerated AES can be detected by compiler-set flags. This removes the case where the full RandenHwAes is built when only ABSL_RANDOM_INTERNAL_AES_DISPATCH is true. This also removes the case where ARM crypto is enabled through the crypto directive. This directive doesn't appear to reliably work when used with arm_neon.h. As far as I can tell, the crypto directive is only meant to work with crypto instructions in handwritten asm. For this to work with arm_neon.h, it appears several hacks are needed, including overriding some compiler-set defines. PiperOrigin-RevId: 392948948 GitOrigin-RevId: e1c30aa6d6bb25987916d3ec39245c6d4a2a93ea Change-Id: Ie97e26f0204c8a86f72d2f38a59181f1ef578418 --- absl/random/internal/BUILD.bazel | 2 +- absl/random/internal/randen_hwaes.cc | 54 +++--------------------------------- 2 files changed, 5 insertions(+), 51 deletions(-) (limited to 'absl/random') diff --git a/absl/random/internal/BUILD.bazel b/absl/random/internal/BUILD.bazel index 8420b5c5..df6e42fc 100644 --- a/absl/random/internal/BUILD.bazel +++ b/absl/random/internal/BUILD.bazel @@ -626,7 +626,7 @@ cc_test( name = "randen_hwaes_test", size = "small", srcs = ["randen_hwaes_test.cc"], - copts = ABSL_TEST_COPTS, + copts = ABSL_TEST_COPTS + ABSL_RANDOM_RANDEN_COPTS, linkopts = ABSL_DEFAULT_LINKOPTS, tags = ABSL_RANDOM_NONPORTABLE_TAGS, deps = [ diff --git a/absl/random/internal/randen_hwaes.cc b/absl/random/internal/randen_hwaes.cc index ab51e4a3..776c2e18 100644 --- a/absl/random/internal/randen_hwaes.cc +++ b/absl/random/internal/randen_hwaes.cc @@ -30,43 +30,13 @@ // ABSL_RANDEN_HWAES_IMPL indicates whether this file will contain // a hardware accelerated implementation of randen, or whether it // will contain stubs that exit the process. -#if defined(ABSL_ARCH_X86_64) || defined(ABSL_ARCH_X86_32) -// The platform.h directives are sufficient to indicate whether -// we should build accelerated implementations for x86. -#if (ABSL_HAVE_ACCELERATED_AES || ABSL_RANDOM_INTERNAL_AES_DISPATCH) -#define ABSL_RANDEN_HWAES_IMPL 1 -#endif -#elif defined(ABSL_ARCH_PPC) -// The platform.h directives are sufficient to indicate whether -// we should build accelerated implementations for PPC. -// -// NOTE: This has mostly been tested on 64-bit Power variants, -// and not embedded cpus such as powerpc32-8540 #if ABSL_HAVE_ACCELERATED_AES +// The following plaforms have implemented RandenHwAws. +#if defined(ABSL_ARCH_X86_64) || defined(ABSL_ARCH_X86_32) || \ + defined(ABSL_ARCH_PPC) || defined(ABSL_ARCH_ARM) || \ + defined(ABSL_ARCH_AARCH64) #define ABSL_RANDEN_HWAES_IMPL 1 #endif -#elif defined(ABSL_ARCH_ARM) || defined(ABSL_ARCH_AARCH64) -// ARM is somewhat more complicated. We might support crypto natively... -#if ABSL_HAVE_ACCELERATED_AES || \ - (defined(__ARM_NEON) && defined(__ARM_FEATURE_CRYPTO)) -#define ABSL_RANDEN_HWAES_IMPL 1 - -#elif ABSL_RANDOM_INTERNAL_AES_DISPATCH && !defined(__APPLE__) && \ - (defined(__GNUC__) && __GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ > 9) -// ...or, on GCC, we can use an ASM directive to -// instruct the assember to allow crypto instructions. -#define ABSL_RANDEN_HWAES_IMPL 1 -#define ABSL_RANDEN_HWAES_IMPL_CRYPTO_DIRECTIVE 1 -#endif -#else -// HWAES is unsupported by these architectures / platforms: -// __myriad2__ -// __mips__ -// -// Other architectures / platforms are unknown. -// -// See the Abseil documentation on supported macros at: -// https://abseil.io/docs/cpp/platforms/macros #endif #if !defined(ABSL_RANDEN_HWAES_IMPL) @@ -192,22 +162,6 @@ inline ABSL_TARGET_CRYPTO void SwapEndian(absl::uint128* state) { #elif defined(ABSL_ARCH_ARM) || defined(ABSL_ARCH_AARCH64) -// This asm directive will cause the file to be compiled with crypto extensions -// whether or not the cpu-architecture supports it. -#if ABSL_RANDEN_HWAES_IMPL_CRYPTO_DIRECTIVE -asm(".arch_extension crypto\n"); - -// Override missing defines. -#if !defined(__ARM_NEON) -#define __ARM_NEON 1 -#endif - -#if !defined(__ARM_FEATURE_CRYPTO) -#define __ARM_FEATURE_CRYPTO 1 -#endif - -#endif - // Rely on the ARM NEON+Crypto advanced simd types, defined in . // uint8x16_t is the user alias for underlying __simd128_uint8_t type. // http://infocenter.arm.com/help/topic/com.arm.doc.ihi0073a/IHI0073A_arm_neon_intrinsics_ref.pdf -- cgit v1.2.3