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-rw-r--r--src/common/x64/cpu_detect.cpp59
-rw-r--r--src/common/x64/cpu_detect.h4
2 files changed, 60 insertions, 3 deletions
diff --git a/src/common/x64/cpu_detect.cpp b/src/common/x64/cpu_detect.cpp
index 1a27532d4..e54383a4a 100644
--- a/src/common/x64/cpu_detect.cpp
+++ b/src/common/x64/cpu_detect.cpp
@@ -4,14 +4,27 @@
#include <array>
#include <cstring>
+#include <fstream>
#include <iterator>
+#include <optional>
#include <string_view>
+#include <thread>
+#include <vector>
#include "common/bit_util.h"
#include "common/common_types.h"
+#include "common/logging/log.h"
#include "common/x64/cpu_detect.h"
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
#ifdef _MSC_VER
#include <intrin.h>
+
+static inline u64 xgetbv(u32 index) {
+ return _xgetbv(index);
+}
#else
#if defined(__DragonFly__) || defined(__FreeBSD__)
@@ -39,12 +52,11 @@ static inline void __cpuid(int info[4], u32 function_id) {
}
#define _XCR_XFEATURE_ENABLED_MASK 0
-static inline u64 _xgetbv(u32 index) {
+static inline u64 xgetbv(u32 index) {
u32 eax, edx;
__asm__ __volatile__("xgetbv" : "=a"(eax), "=d"(edx) : "c"(index));
return ((u64)edx << 32) | eax;
}
-
#endif // _MSC_VER
namespace Common {
@@ -107,7 +119,7 @@ static CPUCaps Detect() {
// - Is the XSAVE bit set in CPUID?
// - XGETBV result has the XCR bit set.
if (Common::Bit<28>(cpu_id[2]) && Common::Bit<27>(cpu_id[2])) {
- if ((_xgetbv(_XCR_XFEATURE_ENABLED_MASK) & 0x6) == 0x6) {
+ if ((xgetbv(_XCR_XFEATURE_ENABLED_MASK) & 0x6) == 0x6) {
caps.avx = true;
if (Common::Bit<12>(cpu_id[2]))
caps.fma = true;
@@ -192,4 +204,45 @@ const CPUCaps& GetCPUCaps() {
return caps;
}
+std::optional<int> GetProcessorCount() {
+#if defined(_WIN32)
+ // Get the buffer length.
+ DWORD length = 0;
+ GetLogicalProcessorInformation(nullptr, &length);
+ if (GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
+ LOG_ERROR(Frontend, "Failed to query core count.");
+ return std::nullopt;
+ }
+ std::vector<SYSTEM_LOGICAL_PROCESSOR_INFORMATION> buffer(
+ length / sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION));
+ // Now query the core count.
+ if (!GetLogicalProcessorInformation(buffer.data(), &length)) {
+ LOG_ERROR(Frontend, "Failed to query core count.");
+ return std::nullopt;
+ }
+ return static_cast<int>(
+ std::count_if(buffer.cbegin(), buffer.cend(), [](const auto& proc_info) {
+ return proc_info.Relationship == RelationProcessorCore;
+ }));
+#elif defined(__unix__)
+ const int thread_count = std::thread::hardware_concurrency();
+ std::ifstream smt("/sys/devices/system/cpu/smt/active");
+ char state = '0';
+ if (smt) {
+ smt.read(&state, sizeof(state));
+ }
+ switch (state) {
+ case '0':
+ return thread_count;
+ case '1':
+ return thread_count / 2;
+ default:
+ return std::nullopt;
+ }
+#else
+ // Shame on you
+ return std::nullopt;
+#endif
+}
+
} // namespace Common
diff --git a/src/common/x64/cpu_detect.h b/src/common/x64/cpu_detect.h
index 6830f3795..ca8db19d6 100644
--- a/src/common/x64/cpu_detect.h
+++ b/src/common/x64/cpu_detect.h
@@ -4,6 +4,7 @@
#pragma once
+#include <optional>
#include <string_view>
#include "common/common_types.h"
@@ -74,4 +75,7 @@ struct CPUCaps {
*/
const CPUCaps& GetCPUCaps();
+/// Detects CPU core count
+std::optional<int> GetProcessorCount();
+
} // namespace Common