/* CpuArch.c -- CPU specific code
2010-10-26: Igor Pavlov : Public domain */

#include "CpuArch.h"

#ifdef MY_CPU_X86_OR_AMD64

#if (defined(_MSC_VER) && !defined(MY_CPU_AMD64)) || defined(__GNUC__) || defined(__clang__)
#define USE_ASM
#endif

#if defined(USE_ASM) && !defined(MY_CPU_AMD64)
static UInt32 CheckFlag(UInt32 flag)
{
#ifdef _MSC_VER
    __asm pushfd;
    __asm pop EAX;
    __asm mov EDX, EAX;
    __asm xor EAX, flag;
    __asm push EAX;
    __asm popfd;
    __asm pushfd;
    __asm pop EAX;
    __asm xor EAX, EDX;
    __asm push EDX;
    __asm popfd;
    __asm and flag, EAX;
#else
    __asm__ __volatile__(
        "pushf\n\t"
        "pop  %%EAX\n\t"
        "movl %%EAX,%%EDX\n\t"
        "xorl %0,%%EAX\n\t"
        "push %%EAX\n\t"
        "popf\n\t"
        "pushf\n\t"
        "pop  %%EAX\n\t"
        "xorl %%EDX,%%EAX\n\t"
        "push %%EDX\n\t"
        "popf\n\t"
        "andl %%EAX, %0\n\t"
        : "=c"(flag)
        : "c"(flag));
#endif
    return flag;
}
#define CHECK_CPUID_IS_SUPPORTED                            \
    if (CheckFlag(1 << 18) == 0 || CheckFlag(1 << 21) == 0) \
        return False;
#else
#define CHECK_CPUID_IS_SUPPORTED
#endif

static void MyCPUID(UInt32 function, UInt32* a, UInt32* b, UInt32* c, UInt32* d)
{
#ifdef USE_ASM

#ifdef _MSC_VER

    UInt32 a2, b2, c2, d2;
    __asm xor EBX, EBX;
    __asm xor ECX, ECX;
    __asm xor EDX, EDX;
    __asm mov EAX, function;
    __asm cpuid;
    __asm mov a2, EAX;
    __asm mov b2, EBX;
    __asm mov c2, ECX;
    __asm mov d2, EDX;

    *a = a2;
    *b = b2;
    *c = c2;
    *d = d2;

#else

    __asm__ __volatile__(
        "cpuid"
        : "=a"(*a),
        "=b"(*b),
        "=c"(*c),
        "=d"(*d)
        : "0"(function));

#endif

#else

    int CPUInfo[4];
    __cpuid(CPUInfo, function);
    *a = CPUInfo[0];
    *b = CPUInfo[1];
    *c = CPUInfo[2];
    *d = CPUInfo[3];

#endif
}

Bool x86cpuid_CheckAndRead(Cx86cpuid* p)
{
    CHECK_CPUID_IS_SUPPORTED
    MyCPUID(0, &p->maxFunc, &p->vendor[0], &p->vendor[2], &p->vendor[1]);
    MyCPUID(1, &p->ver, &p->b, &p->c, &p->d);
    return True;
}

static UInt32 kVendors[][3] = {
    { 0x756E6547, 0x49656E69, 0x6C65746E },
    { 0x68747541, 0x69746E65, 0x444D4163 },
    { 0x746E6543, 0x48727561, 0x736C7561 }
};

int x86cpuid_GetFirm(const Cx86cpuid* p)
{
    unsigned i;
    for (i = 0; i < sizeof(kVendors) / sizeof(kVendors[i]); i++) {
        const UInt32* v = kVendors[i];
        if (v[0] == p->vendor[0] && v[1] == p->vendor[1] && v[2] == p->vendor[2])
            return (int)i;
    }
    return -1;
}

Bool CPU_Is_InOrder()
{
    Cx86cpuid p;
    int firm;
    UInt32 family, model;
    if (!x86cpuid_CheckAndRead(&p))
        return True;
    family = x86cpuid_GetFamily(&p);
    model = x86cpuid_GetModel(&p);
    firm = x86cpuid_GetFirm(&p);
    switch (firm) {
    case CPU_FIRM_INTEL:
        return (family < 6 || (family == 6 && model == 0x100C));
    case CPU_FIRM_AMD:
        return (family < 5 || (family == 5 && (model < 6 || model == 0xA)));
    case CPU_FIRM_VIA:
        return (family < 6 || (family == 6 && model < 0xF));
    }
    return True;
}

#if !defined(MY_CPU_AMD64) && defined(_WIN32)
static Bool CPU_Sys_Is_SSE_Supported()
{
    OSVERSIONINFO vi;
    vi.dwOSVersionInfoSize = sizeof(vi);
    if (!GetVersionEx(&vi))
        return False;
    return (vi.dwMajorVersion >= 5);
}
#define CHECK_SYS_SSE_SUPPORT        \
    if (!CPU_Sys_Is_SSE_Supported()) \
        return False;
#else
#define CHECK_SYS_SSE_SUPPORT
#endif

Bool CPU_Is_Aes_Supported()
{
    Cx86cpuid p;
    CHECK_SYS_SSE_SUPPORT
    if (!x86cpuid_CheckAndRead(&p))
        return False;
    return (p.c >> 25) & 1;
}

#endif
