| // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #include "vm/globals.h" |
| #if defined(TARGET_ARCH_ARM) |
| |
| #include "vm/cpu.h" |
| #include "vm/cpu_arm.h" |
| |
| #include "vm/cpuinfo.h" |
| #include "vm/heap/heap.h" |
| #include "vm/isolate.h" |
| #include "vm/object.h" |
| #include "vm/simulator.h" |
| |
| #if defined(DART_HOST_OS_IOS) |
| #include <libkern/OSCacheControl.h> |
| #endif |
| |
| #if !defined(TARGET_HOST_MISMATCH) |
| #include <sys/syscall.h> /* NOLINT */ |
| #include <unistd.h> /* NOLINT */ |
| #endif |
| |
| // ARM version differences. |
| // We support only ARMv7 and variants. We detect the presence of vfp, |
| // neon, and integer division instructions. Considering ARMv5TE as the baseline, |
| // later versions add the following features/instructions that we use: |
| // |
| // ARMv6: |
| // - PC read offset in store instructions is 8 rather than 12, matching the |
| // offset in read instructions, |
| // - strex, ldrex, and clrex load/store/clear exclusive instructions, |
| // - umaal multiplication instruction, |
| // ARMv7: |
| // - movw, movt 16-bit immediate load instructions, |
| // - mls multiplication instruction, |
| // - vmovs, vmovd floating point immediate load instructions. |
| // |
| // If an aarch64 CPU is detected, we generate ARMv7 code. |
| // |
| // Where we are missing vfp, we do not unbox doubles, or generate intrinsics for |
| // floating point operations. Where we are missing neon, we do not unbox SIMD |
| // values, or inline operations on SIMD values. Where we are missing integer |
| // division, we do not inline division operations, and we do not generate |
| // intrinsics that do division. See the feature tests in flow_graph_optimizer.cc |
| // for details. |
| |
| namespace dart { |
| |
| DEFINE_FLAG(bool, use_vfp, true, "Use vfp instructions if supported"); |
| DEFINE_FLAG(bool, use_neon, true, "Use neon instructions if supported"); |
| DEFINE_FLAG(bool, |
| use_integer_division, |
| true, |
| "Use integer division instruction if supported"); |
| |
| #if defined(TARGET_HOST_MISMATCH) |
| #if defined(DART_TARGET_OS_ANDROID) || defined(DART_TARGET_OS_MACOS_IOS) |
| DEFINE_FLAG(bool, sim_use_hardfp, false, "Use the hardfp ABI."); |
| #else |
| DEFINE_FLAG(bool, sim_use_hardfp, true, "Use the hardfp ABI."); |
| #endif |
| #endif |
| |
| void CPU::FlushICache(uword start, uword size) { |
| #if defined(DART_PRECOMPILED_RUNTIME) |
| UNREACHABLE(); |
| #elif !defined(TARGET_HOST_MISMATCH) && HOST_ARCH_ARM |
| // Nothing to do. Flushing no instructions. |
| if (size == 0) { |
| return; |
| } |
| |
| // ARM recommends using the gcc intrinsic __clear_cache on Linux, and the |
| // library call cacheflush from unistd.h on Android: |
| // |
| // https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/caches-and-self-modifying-code |
| // |
| // On iOS we use sys_icache_invalidate from Darwin. See: |
| // |
| // https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/sys_icache_invalidate.3.html |
| #if defined(DART_HOST_OS_IOS) |
| sys_icache_invalidate(reinterpret_cast<void*>(start), size); |
| #elif defined(__linux__) && !defined(ANDROID) |
| extern void __clear_cache(char*, char*); |
| char* beg = reinterpret_cast<char*>(start); |
| char* end = reinterpret_cast<char*>(start + size); |
| ::__clear_cache(beg, end); |
| #elif defined(ANDROID) |
| cacheflush(start, start + size, 0); |
| #else |
| #error FlushICache only tested/supported on Linux, Android and iOS |
| #endif |
| #endif |
| } |
| |
| const char* CPU::Id() { |
| return |
| #if defined(TARGET_HOST_MISMATCH) |
| "sim" |
| #endif // defined(TARGET_HOST_MISMATCH) |
| "arm"; |
| } |
| |
| bool HostCPUFeatures::integer_division_supported_ = false; |
| bool HostCPUFeatures::vfp_supported_ = false; |
| bool HostCPUFeatures::neon_supported_ = false; |
| bool HostCPUFeatures::hardfp_supported_ = false; |
| const char* HostCPUFeatures::hardware_ = NULL; |
| intptr_t HostCPUFeatures::store_pc_read_offset_ = 8; |
| #if defined(DEBUG) |
| bool HostCPUFeatures::initialized_ = false; |
| #endif |
| |
| #if !defined(TARGET_HOST_MISMATCH) |
| #if DART_HOST_OS_IOS |
| void HostCPUFeatures::Init() { |
| // TODO(24743): Actually check the CPU features and fail if we're missing |
| // something assumed in a precompiled snapshot. |
| hardware_ = ""; |
| // When the VM is targetted to ARMv7, pretend that the CPU is ARMv7 even if |
| // the CPU is actually AArch64. |
| vfp_supported_ = FLAG_use_vfp; |
| integer_division_supported_ = FLAG_use_integer_division; |
| neon_supported_ = FLAG_use_neon; |
| hardfp_supported_ = false; |
| #if defined(DEBUG) |
| initialized_ = true; |
| #endif |
| } |
| #else // DART_HOST_OS_IOS |
| void HostCPUFeatures::Init() { |
| bool is_arm64 = false; |
| CpuInfo::Init(); |
| hardware_ = CpuInfo::GetCpuModel(); |
| |
| // Check for ARMv7, or aarch64. |
| // It can be in either the Processor or Model information fields. |
| if (CpuInfo::FieldContains(kCpuInfoProcessor, "aarch64") || |
| CpuInfo::FieldContains(kCpuInfoModel, "aarch64") || |
| CpuInfo::FieldContains(kCpuInfoArchitecture, "8") || |
| CpuInfo::FieldContains(kCpuInfoArchitecture, "AArch64")) { |
| // pretend that this arm64 cpu is really an ARMv7 |
| is_arm64 = true; |
| } else if (!CpuInfo::FieldContains(kCpuInfoProcessor, "ARMv7") && |
| !CpuInfo::FieldContains(kCpuInfoModel, "ARMv7") && |
| !CpuInfo::FieldContains(kCpuInfoArchitecture, "7")) { |
| #if !defined(DART_RUN_IN_QEMU_ARMv7) |
| FATAL("Unrecognized ARM CPU architecture."); |
| #endif |
| } |
| |
| #if defined(DART_RUN_IN_QEMU_ARMv7) |
| vfp_supported_ = true; |
| #else |
| // Has floating point unit. |
| vfp_supported_ = |
| (CpuInfo::FieldContains(kCpuInfoFeatures, "vfp") || is_arm64) && |
| FLAG_use_vfp; |
| #endif |
| |
| // Has integer division. |
| // Special cases: |
| // - Qualcomm Krait CPUs (QCT APQ8064) in Nexus 4 and 7 incorrectly report |
| // that they lack integer division. |
| // - Marvell Armada 370/XP incorrectly reports that it has integer division. |
| bool is_krait = CpuInfo::FieldContains(kCpuInfoHardware, "QCT APQ8064"); |
| bool is_armada_370xp = |
| CpuInfo::FieldContains(kCpuInfoHardware, "Marvell Armada 370/XP"); |
| bool is_virtual_machine = |
| CpuInfo::FieldContains(kCpuInfoHardware, "Dummy Virtual Machine"); |
| #if defined(DART_HOST_OS_ANDROID) |
| bool is_android = true; |
| #else |
| bool is_android = false; |
| #endif |
| if (is_krait) { |
| integer_division_supported_ = FLAG_use_integer_division; |
| } else if (is_android && is_arm64) { |
| // Various Android ARM64 devices, including the Qualcomm Snapdragon 820/821 |
| // CPUs (MSM 8996 and MSM8996pro) in Xiaomi MI5 and Pixel lack integer |
| // division even though ARMv8 requires it in A32. Instead of attempting to |
| // track all of these devices, we conservatively disable use of integer |
| // division on Android ARM64 devices. |
| // TODO(29270): /proc/self/auxv might be more reliable here. |
| integer_division_supported_ = false; |
| } else if (is_armada_370xp) { |
| integer_division_supported_ = false; |
| } else if (is_android && !is_arm64 && is_virtual_machine) { |
| // Some Android ARM emulators claim support for integer division in |
| // /proc/cpuinfo but do not actually support it. |
| integer_division_supported_ = false; |
| } else { |
| integer_division_supported_ = |
| (CpuInfo::FieldContains(kCpuInfoFeatures, "idiva") || is_arm64) && |
| FLAG_use_integer_division; |
| } |
| neon_supported_ = |
| (CpuInfo::FieldContains(kCpuInfoFeatures, "neon") || is_arm64) && |
| FLAG_use_vfp && FLAG_use_neon; |
| |
| // Use the cross-compiler's predefined macros to determine whether we should |
| // use the hard or soft float ABI. |
| #if defined(__ARM_PCS_VFP) || defined(DART_RUN_IN_QEMU_ARMv7) |
| hardfp_supported_ = true; |
| #else |
| hardfp_supported_ = false; |
| #endif |
| |
| #if defined(DEBUG) |
| initialized_ = true; |
| #endif |
| } |
| #endif // DART_HOST_OS_IOS |
| |
| void HostCPUFeatures::Cleanup() { |
| DEBUG_ASSERT(initialized_); |
| #if defined(DEBUG) |
| initialized_ = false; |
| #endif |
| ASSERT(hardware_ != NULL); |
| free(const_cast<char*>(hardware_)); |
| hardware_ = NULL; |
| CpuInfo::Cleanup(); |
| } |
| |
| #else |
| |
| void HostCPUFeatures::Init() { |
| CpuInfo::Init(); |
| hardware_ = CpuInfo::GetCpuModel(); |
| |
| integer_division_supported_ = FLAG_use_integer_division; |
| vfp_supported_ = FLAG_use_vfp; |
| neon_supported_ = FLAG_use_vfp && FLAG_use_neon; |
| hardfp_supported_ = FLAG_sim_use_hardfp; |
| #if defined(DEBUG) |
| initialized_ = true; |
| #endif |
| } |
| |
| void HostCPUFeatures::Cleanup() { |
| DEBUG_ASSERT(initialized_); |
| #if defined(DEBUG) |
| initialized_ = false; |
| #endif |
| ASSERT(hardware_ != NULL); |
| free(const_cast<char*>(hardware_)); |
| hardware_ = NULL; |
| CpuInfo::Cleanup(); |
| } |
| #endif // !defined(TARGET_HOST_MISMATCH) |
| |
| } // namespace dart |
| |
| #endif // defined TARGET_ARCH_ARM |