diff options
Diffstat (limited to 'absl/crc/internal/cpu_detect.cc')
| -rw-r--r-- | absl/crc/internal/cpu_detect.cc | 79 |
1 files changed, 40 insertions, 39 deletions
diff --git a/absl/crc/internal/cpu_detect.cc b/absl/crc/internal/cpu_detect.cc index 339b7cc7..253c71fd 100644 --- a/absl/crc/internal/cpu_detect.cc +++ b/absl/crc/internal/cpu_detect.cc @@ -24,30 +24,29 @@ #include <sys/auxv.h> #endif +#if defined(_WIN32) || defined(_WIN64) +#include <intrin.h> +#endif + namespace absl { ABSL_NAMESPACE_BEGIN namespace crc_internal { -#if defined(__x86_64__) - -// Inline cpuid instruction. %rbx is occasionally used to address stack -// variables in presence of dynamic allocas. Preserve the %rbx register via -// %rdi to work around a clang bug https://bugs.llvm.org/show_bug.cgi?id=17907 -// (%rbx in an output constraint is not considered a clobbered register). -// -// a_inp and c_inp are the input parameters eax and ecx of the CPUID -// instruction. -// a, b, c, and d contain the contents of eax, ebx, ecx, and edx as returned by -// the CPUID instruction -#define ABSL_INTERNAL_GETCPUID(a, b, c, d, a_inp, c_inp) \ - asm("mov %%rbx, %%rdi\n" \ - "cpuid\n" \ - "xchg %%rdi, %%rbx\n" \ - : "=a"(a), "=D"(b), "=c"(c), "=d"(d) \ - : "a"(a_inp), "2"(c_inp)) +#if defined(__x86_64__) || defined(_M_X64) namespace { +#if !defined(_WIN32) && !defined(_WIN64) +// MSVC defines this function for us. +// https://learn.microsoft.com/en-us/cpp/intrinsics/cpuid-cpuidex +static void __cpuid(int cpu_info[4], int info_type) { + __asm__ volatile("cpuid \n\t" + : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), + "=d"(cpu_info[3]) + : "a"(info_type), "c"(0)); +} +#endif // !defined(_WIN32) && !defined(_WIN64) + enum class Vendor { kUnknown, kIntel, @@ -55,14 +54,14 @@ enum class Vendor { }; Vendor GetVendor() { - uint32_t eax, ebx, ecx, edx; + // Get the vendor string (issue CPUID with eax = 0). + int cpu_info[4]; + __cpuid(cpu_info, 0); - // Get vendor string (issue CPUID with eax = 0) - ABSL_INTERNAL_GETCPUID(eax, ebx, ecx, edx, 0, 0); std::string vendor; - vendor.append(reinterpret_cast<char*>(&ebx), 4); - vendor.append(reinterpret_cast<char*>(&edx), 4); - vendor.append(reinterpret_cast<char*>(&ecx), 4); + vendor.append(reinterpret_cast<char*>(&cpu_info[1]), 4); + vendor.append(reinterpret_cast<char*>(&cpu_info[3]), 4); + vendor.append(reinterpret_cast<char*>(&cpu_info[2]), 4); if (vendor == "GenuineIntel") { return Vendor::kIntel; } else if (vendor == "AuthenticAmd") { @@ -73,13 +72,14 @@ Vendor GetVendor() { } CpuType GetIntelCpuType() { - uint32_t eax, ebx, ecx, edx; - // to get general information and extended features we send eax = 1 and + // To get general information and extended features we send eax = 1 and // ecx = 0 to cpuid. The response is returned in eax, ebx, ecx and edx. // (See Intel 64 and IA-32 Architectures Software Developer's Manual // Volume 2A: Instruction Set Reference, A-M CPUID). // https://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-vol-2a-manual.html - ABSL_INTERNAL_GETCPUID(eax, ebx, ecx, edx, 1, 0); + // https://learn.microsoft.com/en-us/cpp/intrinsics/cpuid-cpuidex + int cpu_info[4]; + __cpuid(cpu_info, 1); // Response in eax bits as follows: // 0-3 (stepping id) @@ -89,12 +89,12 @@ CpuType GetIntelCpuType() { // 16-19 (extended model) // 20-27 (extended family) - int family = (eax >> 8) & 0x0f; - int model_num = (eax >> 4) & 0x0f; - int ext_family = (eax >> 20) & 0xff; - int ext_model_num = (eax >> 16) & 0x0f; + int family = (cpu_info[0] >> 8) & 0x0f; + int model_num = (cpu_info[0] >> 4) & 0x0f; + int ext_family = (cpu_info[0] >> 20) & 0xff; + int ext_model_num = (cpu_info[0] >> 16) & 0x0f; - int brand_id = ebx & 0xff; + int brand_id = cpu_info[1] & 0xff; // Process the extended family and model info if necessary if (family == 0x0f) { @@ -123,7 +123,7 @@ CpuType GetIntelCpuType() { case 0x56: // BroadwellDE return CpuType::kIntelBroadwell; case 0x55: // Skylake Xeon - if ((eax & 0x0f) < 5) { // stepping < 5 is skylake + if ((cpu_info[0] & 0x0f) < 5) { // stepping < 5 is skylake return CpuType::kIntelSkylakeXeon; } else { // stepping >= 5 is cascadelake return CpuType::kIntelCascadelakeXeon; @@ -142,12 +142,13 @@ CpuType GetIntelCpuType() { } CpuType GetAmdCpuType() { - uint32_t eax, ebx, ecx, edx; - // to get general information and extended features we send eax = 1 and + // To get general information and extended features we send eax = 1 and // ecx = 0 to cpuid. The response is returned in eax, ebx, ecx and edx. // (See Intel 64 and IA-32 Architectures Software Developer's Manual // Volume 2A: Instruction Set Reference, A-M CPUID). - ABSL_INTERNAL_GETCPUID(eax, ebx, ecx, edx, 1, 0); + // https://learn.microsoft.com/en-us/cpp/intrinsics/cpuid-cpuidex + int cpu_info[4]; + __cpuid(cpu_info, 1); // Response in eax bits as follows: // 0-3 (stepping id) @@ -157,10 +158,10 @@ CpuType GetAmdCpuType() { // 16-19 (extended model) // 20-27 (extended family) - int family = (eax >> 8) & 0x0f; - int model_num = (eax >> 4) & 0x0f; - int ext_family = (eax >> 20) & 0xff; - int ext_model_num = (eax >> 16) & 0x0f; + int family = (cpu_info[0] >> 8) & 0x0f; + int model_num = (cpu_info[0] >> 4) & 0x0f; + int ext_family = (cpu_info[0] >> 20) & 0xff; + int ext_model_num = (cpu_info[0] >> 16) & 0x0f; if (family == 0x0f) { family += ext_family; |