llvm/compiler-rt/lib/builtins/cpu_model/x86.c

//===-- cpu_model/x86.c - Support for __cpu_model builtin  --------*- C -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
//  This file is based on LLVM's lib/Support/Host.cpp.
//  It implements the operating system Host concept and builtin
//  __cpu_model for the compiler_rt library for x86.
//
//===----------------------------------------------------------------------===//

#include "cpu_model.h"

#if !(defined(__i386__) || defined(_M_IX86) || defined(__x86_64__) ||          \
      defined(_M_X64))
#error This file is intended only for x86-based targets
#endif

#if defined(__GNUC__) || defined(__clang__) || defined(_MSC_VER)

#include <assert.h>

#if (defined(__GNUC__) || defined(__clang__)) && !defined(_MSC_VER)
#include <cpuid.h>
#endif

#ifdef _MSC_VER
#include <intrin.h>
#endif

enum VendorSignatures { … };

enum ProcessorVendors { … };

enum ProcessorTypes { … };

enum ProcessorSubtypes { … };

enum ProcessorFeatures { … };

// This code is copied from lib/Support/Host.cpp.
// Changes to either file should be mirrored in the other.

/// getX86CpuIDAndInfo - Execute the specified cpuid and return the 4 values in
/// the specified arguments.  If we can't run cpuid on the host, return true.
static bool getX86CpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
                               unsigned *rECX, unsigned *rEDX) { … }

/// getX86CpuIDAndInfoEx - Execute the specified cpuid with subleaf and return
/// the 4 values in the specified arguments.  If we can't run cpuid on the host,
/// return true.
static bool getX86CpuIDAndInfoEx(unsigned value, unsigned subleaf,
                                 unsigned *rEAX, unsigned *rEBX, unsigned *rECX,
                                 unsigned *rEDX) { … }

// Read control register 0 (XCR0). Used to detect features such as AVX.
static bool getX86XCR0(unsigned *rEAX, unsigned *rEDX) { … }

static void detectX86FamilyModel(unsigned EAX, unsigned *Family,
                                 unsigned *Model) { … }

#define testFeature …

static const char *getIntelProcessorTypeAndSubtype(unsigned Family,
                                                   unsigned Model,
                                                   const unsigned *Features,
                                                   unsigned *Type,
                                                   unsigned *Subtype) { … }

static const char *getAMDProcessorTypeAndSubtype(unsigned Family,
                                                 unsigned Model,
                                                 const unsigned *Features,
                                                 unsigned *Type,
                                                 unsigned *Subtype) { … }

#undef testFeature

static void getAvailableFeatures(unsigned ECX, unsigned EDX, unsigned MaxLeaf,
                                 unsigned *Features) { … }

#ifndef _WIN32
__attribute__((visibility("hidden")))
#endif
int __cpu_indicator_init(void) CONSTRUCTOR_ATTRIBUTE;

#ifndef _WIN32
__attribute__((visibility("hidden")))
#endif
struct __processor_model { … } __cpu_model = …;

#ifndef _WIN32
__attribute__((visibility("hidden")))
#endif
unsigned __cpu_features2[(CPU_FEATURE_MAX - 1) / 32];

// A constructor function that is sets __cpu_model and __cpu_features2 with
// the right values.  This needs to run only once.  This constructor is
// given the highest priority and it should run before constructors without
// the priority set.  However, it still runs after ifunc initializers and
// needs to be called explicitly there.

int CONSTRUCTOR_ATTRIBUTE __cpu_indicator_init(void) { … }
#endif // defined(__GNUC__) || defined(__clang__) || defined(_MSC_VER)