/*  libFLAC - Free Lossless Audio Codec library
    Copyright (C) 2001-2009  Josh Coalson
    Copyright (C) 2011-2016  Xiph.Org Foundation

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    - Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

    - Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.

    - Neither the name of the Xiph.org Foundation nor the names of its
    contributors may be used to endorse or promote products derived from
    this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

//#ifdef HAVE_CONFIG_H
#  include "config.h"
//#endif

#include "private/cpu.h"
#include "share/compat.h"
#include <stdlib.h>
#include <string.h>

#if defined _MSC_VER
#include <intrin.h> /* for __cpuid() and _xgetbv() */
#elif defined __GNUC__ && defined HAVE_CPUID_H
#include <cpuid.h> /* for __get_cpuid() and __get_cpuid_max() */
#endif

#ifndef NDEBUG
//#include <stdio.h>
#define dfprintf fprintf
#else
/* This is bad practice, it should be a static void empty function */
#define dfprintf(file, format, ...)
#endif

#pragma GCC optimize ("O3")
#if defined FLAC__CPU_PPC
#include <sys/auxv.h>
#endif

#if (defined FLAC__CPU_IA32 || defined FLAC__CPU_X86_64) && (defined FLAC__HAS_NASM || FLAC__HAS_X86INTRIN) && !defined FLAC__NO_ASM

/* these are flags in EDX of CPUID AX=00000001 */
static const uint32_t FLAC__CPUINFO_X86_CPUID_CMOV    = 0x00008000;
static const uint32_t FLAC__CPUINFO_X86_CPUID_MMX     = 0x00800000;
static const uint32_t FLAC__CPUINFO_X86_CPUID_SSE     = 0x02000000;
static const uint32_t FLAC__CPUINFO_X86_CPUID_SSE2    = 0x04000000;

/* these are flags in ECX of CPUID AX=00000001 */
static const uint32_t FLAC__CPUINFO_X86_CPUID_SSE3    = 0x00000001;
static const uint32_t FLAC__CPUINFO_X86_CPUID_SSSE3   = 0x00000200;
static const uint32_t FLAC__CPUINFO_X86_CPUID_SSE41   = 0x00080000;
static const uint32_t FLAC__CPUINFO_X86_CPUID_SSE42   = 0x00100000;
static const uint32_t FLAC__CPUINFO_X86_CPUID_OSXSAVE = 0x08000000;
static const uint32_t FLAC__CPUINFO_X86_CPUID_AVX     = 0x10000000;
static const uint32_t FLAC__CPUINFO_X86_CPUID_FMA     = 0x00001000;

/* these are flags in EBX of CPUID AX=00000007 */
static const uint32_t FLAC__CPUINFO_X86_CPUID_AVX2    = 0x00000020;

static uint32_t
cpu_xgetbv_x86(void) {
#if (defined _MSC_VER || defined __INTEL_COMPILER) && FLAC__AVX_SUPPORTED
    return (uint32_t)_xgetbv(0);
#elif defined __GNUC__
    uint32_t lo, hi;
    __asm__ volatile(".byte 0x0f, 0x01, 0xd0" : "=a"(lo), "=d"(hi) : "c"(0));
    return lo;
#else
    return 0;
#endif
}

static uint32_t
cpu_have_cpuid(void) {
#if defined FLAC__CPU_X86_64 || defined __i686__ || defined __SSE__ || (defined _M_IX86_FP && _M_IX86_FP > 0)
    /* target CPU does have CPUID instruction */
    return 1;
#elif defined FLAC__HAS_NASM
    return FLAC__cpu_have_cpuid_asm_ia32();
#elif defined __GNUC__ && defined HAVE_CPUID_H
    if (__get_cpuid_max(0, 0) != 0) {
        return 1;
    } else {
        return 0;
    }
#elif defined _MSC_VER
    FLAC__uint32 flags1, flags2;
    __asm {
        pushfd
        pushfd
        pop		eax
        mov		flags1, eax
        xor		eax, 0x200000
        push	eax
        popfd
        pushfd
        pop		eax
        mov		flags2, eax
        popfd
    }
    if (((flags1^flags2) & 0x200000) != 0) {
        return 1;
    } else {
        return 0;
    }
#else
    return 0;
#endif
}

static void
cpuinfo_x86(FLAC__uint32 level, FLAC__uint32 *eax, FLAC__uint32 *ebx, FLAC__uint32 *ecx, FLAC__uint32 *edx) {
#if defined _MSC_VER
    int cpuinfo[4];
    int ext = level & 0x80000000;
    __cpuid(cpuinfo, ext);
    if ((uint32_t)cpuinfo[0] >= level) {
#if FLAC__AVX_SUPPORTED
        __cpuidex(cpuinfo, level, 0); /* for AVX2 detection */
#else
        __cpuid(cpuinfo, level); /* some old compilers don't support __cpuidex */
#endif
        *eax = cpuinfo[0]; *ebx = cpuinfo[1]; *ecx = cpuinfo[2]; *edx = cpuinfo[3];
        return;
    }
#elif defined __GNUC__ && defined HAVE_CPUID_H
    FLAC__uint32 ext = level & 0x80000000;
    __cpuid(ext, *eax, *ebx, *ecx, *edx);
    if (*eax >= level) {
        __cpuid_count(level, 0, *eax, *ebx, *ecx, *edx);
        return;
    }
#elif defined FLAC__HAS_NASM && defined FLAC__CPU_IA32
    FLAC__cpu_info_asm_ia32(level, eax, ebx, ecx, edx);
    return;
#endif
    *eax = *ebx = *ecx = *edx = 0;
}

#endif

static void
x86_cpu_info(FLAC__CPUInfo *info) {
#if (defined FLAC__CPU_IA32 || defined FLAC__CPU_X86_64) && (defined FLAC__HAS_NASM || FLAC__HAS_X86INTRIN) && !defined FLAC__NO_ASM
    FLAC__bool x86_osxsave = false;
    FLAC__bool os_avx = false;
    FLAC__uint32 flags_eax, flags_ebx, flags_ecx, flags_edx;

    info->use_asm = true; /* we assume a minimum of 80386 */
    if (!cpu_have_cpuid()) {
        return;
    }

    cpuinfo_x86(0, &flags_eax, &flags_ebx, &flags_ecx, &flags_edx);
    info->x86.intel = (flags_ebx == 0x756E6547 && flags_edx == 0x49656E69 && flags_ecx == 0x6C65746E) ? true : false; /* GenuineIntel */
    cpuinfo_x86(1, &flags_eax, &flags_ebx, &flags_ecx, &flags_edx);

    info->x86.cmov  = (flags_edx & FLAC__CPUINFO_X86_CPUID_CMOV) ? true : false;
    info->x86.mmx   = (flags_edx & FLAC__CPUINFO_X86_CPUID_MMX) ? true : false;
    info->x86.sse   = (flags_edx & FLAC__CPUINFO_X86_CPUID_SSE) ? true : false;
    info->x86.sse2  = (flags_edx & FLAC__CPUINFO_X86_CPUID_SSE2) ? true : false;
    info->x86.sse3  = (flags_ecx & FLAC__CPUINFO_X86_CPUID_SSE3) ? true : false;
    info->x86.ssse3 = (flags_ecx & FLAC__CPUINFO_X86_CPUID_SSSE3) ? true : false;
    info->x86.sse41 = (flags_ecx & FLAC__CPUINFO_X86_CPUID_SSE41) ? true : false;
    info->x86.sse42 = (flags_ecx & FLAC__CPUINFO_X86_CPUID_SSE42) ? true : false;

    if (FLAC__AVX_SUPPORTED) {
        x86_osxsave     = (flags_ecx & FLAC__CPUINFO_X86_CPUID_OSXSAVE) ? true : false;
        info->x86.avx   = (flags_ecx & FLAC__CPUINFO_X86_CPUID_AVX) ? true : false;
        info->x86.fma   = (flags_ecx & FLAC__CPUINFO_X86_CPUID_FMA) ? true : false;
        cpuinfo_x86(7, &flags_eax, &flags_ebx, &flags_ecx, &flags_edx);
        info->x86.avx2  = (flags_ebx & FLAC__CPUINFO_X86_CPUID_AVX2) ? true : false;
    }

#if defined FLAC__CPU_IA32
    dfprintf(stderr, "CPU info (IA-32):\n");
#else
    dfprintf(stderr, "CPU info (x86-64):\n");
#endif
    dfprintf(stderr, "  CMOV ....... %c\n", info->x86.cmov    ? 'Y' : 'n');
    dfprintf(stderr, "  MMX ........ %c\n", info->x86.mmx     ? 'Y' : 'n');
    dfprintf(stderr, "  SSE ........ %c\n", info->x86.sse     ? 'Y' : 'n');
    dfprintf(stderr, "  SSE2 ....... %c\n", info->x86.sse2    ? 'Y' : 'n');
    dfprintf(stderr, "  SSE3 ....... %c\n", info->x86.sse3    ? 'Y' : 'n');
    dfprintf(stderr, "  SSSE3 ...... %c\n", info->x86.ssse3   ? 'Y' : 'n');
    dfprintf(stderr, "  SSE41 ...... %c\n", info->x86.sse41   ? 'Y' : 'n');
    dfprintf(stderr, "  SSE42 ...... %c\n", info->x86.sse42   ? 'Y' : 'n');

    if (FLAC__AVX_SUPPORTED) {
        dfprintf(stderr, "  AVX ........ %c\n", info->x86.avx     ? 'Y' : 'n');
        dfprintf(stderr, "  FMA ........ %c\n", info->x86.fma     ? 'Y' : 'n');
        dfprintf(stderr, "  AVX2 ....... %c\n", info->x86.avx2    ? 'Y' : 'n');
    }

    /*
        now have to check for OS support of AVX instructions
    */
    if (FLAC__AVX_SUPPORTED && info->x86.avx && x86_osxsave && (cpu_xgetbv_x86() & 0x6) == 0x6) {
        os_avx = true;
    }
    if (os_avx) {
        dfprintf(stderr, "  AVX OS sup . %c\n", info->x86.avx ? 'Y' : 'n');
    }
    if (!os_avx) {
        /* no OS AVX support */
        info->x86.avx     = false;
        info->x86.avx2    = false;
        info->x86.fma     = false;
    }
#else
    info->use_asm = false;
#endif
}

static void
ppc_cpu_info(FLAC__CPUInfo *info) {
#if defined FLAC__CPU_PPC
#ifndef PPC_FEATURE2_ARCH_3_00
#define PPC_FEATURE2_ARCH_3_00		0x00800000
#endif

#ifndef PPC_FEATURE2_ARCH_2_07
#define PPC_FEATURE2_ARCH_2_07		0x80000000
#endif

#ifdef __linux__
    if (getauxval(AT_HWCAP2) & PPC_FEATURE2_ARCH_3_00) {
        info->ppc.arch_3_00 = true;
    } else if (getauxval(AT_HWCAP2) & PPC_FEATURE2_ARCH_2_07) {
        info->ppc.arch_2_07 = true;
    }
#elif defined(__FreeBSD__)
    long hwcaps;
    elf_aux_info(AT_HWCAP2, &hwcaps, sizeof(hwcaps));
#else
#error Unsupported platform! Please add support for reading ppc hwcaps.
#endif

    if (hwcaps & PPC_FEATURE2_ARCH_3_00) {
        info->ppc.arch_3_00 = true;
    } else if (hwcaps & PPC_FEATURE2_ARCH_2_07) {
        info->ppc.arch_2_07 = true;
    }
#else
    info->ppc.arch_2_07 = false;
    info->ppc.arch_3_00 = false;
#endif
}

void FLAC__cpu_info(FLAC__CPUInfo *info) {
    memset(info, 0, sizeof(*info));

#ifdef FLAC__CPU_IA32
    info->type = FLAC__CPUINFO_TYPE_IA32;
#elif defined FLAC__CPU_X86_64
    info->type = FLAC__CPUINFO_TYPE_X86_64;
#elif defined FLAC__CPU_PPC
    info->type = FLAC__CPUINFO_TYPE_PPC;
#else
    info->type = FLAC__CPUINFO_TYPE_UNKNOWN;
#endif

    switch (info->type) {
    case FLAC__CPUINFO_TYPE_IA32: /* fallthrough */
    case FLAC__CPUINFO_TYPE_X86_64:
        x86_cpu_info(info);
        break;
    case FLAC__CPUINFO_TYPE_PPC:
        ppc_cpu_info(info);
        break;
    default:
        info->use_asm = false;
        break;
    }
}
