redgpu/ispc: Intel® Implicit SPMD Program Compiler

src/ispc.cpp
1 739 строк61 KB
Deepak Rajendrakumaran
fixes #1926 : Implementing compile time tracing mechanism.
09 дек 2020, 06:29
09 дек 2020, 06:29d79fea8
/*
  Copyright (c) 2010-2020, Intel Corporation
  All rights reserved.

  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 Intel Corporation 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 COPYRIGHT OWNER
   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.
*/

/** @file ispc.cpp
    @brief ispc global definitions
*/

#include "ispc.h"
#include "llvmutil.h"
#include "module.h"
#include "util.h"

#include <sstream>
#include <stdarg.h> /* va_list, va_start, va_arg, va_end */
#include <stdio.h>
#ifdef ISPC_HOST_IS_WINDOWS
#include <direct.h>
#include <windows.h>
#define strcasecmp stricmp
#include <intrin.h>
#else // !ISPC_HOST_IS_WINDOWS
#include <sys/types.h>
#include <unistd.h>
#endif // ISPC_HOST_IS_WINDOWS

#include <llvm/BinaryFormat/Dwarf.h>
#include <llvm/CodeGen/TargetLowering.h>
#include <llvm/CodeGen/TargetSubtargetInfo.h>
#include <llvm/IR/Attributes.h>
#include <llvm/IR/DIBuilder.h>
#include <llvm/IR/DataLayout.h>
#include <llvm/IR/DebugInfo.h>
#include <llvm/IR/Instructions.h>
#include <llvm/IR/LLVMContext.h>
#include <llvm/IR/Module.h>
#include <llvm/Support/CodeGen.h>
#include <llvm/Support/Host.h>
#include <llvm/Support/TargetRegistry.h>
#include <llvm/Support/TargetSelect.h>
#include <llvm/Target/TargetMachine.h>
#include <llvm/Target/TargetOptions.h>

Globals *g;
Module *m;

///////////////////////////////////////////////////////////////////////////
// Target

#if defined(__arm__) || defined(__aarch64__)
#define ARM_HOST
#endif

#if !defined(ISPC_HOST_IS_WINDOWS) && !defined(ARM_HOST)
// __cpuid() and __cpuidex() are defined on Windows in <intrin.h> for x86/x64.
// On *nix they need to be defined manually through inline assembler.
static void __cpuid(int info[4], int infoType) {
    __asm__ __volatile__("cpuid" : "=a"(info[0]), "=b"(info[1]), "=c"(info[2]), "=d"(info[3]) : "0"(infoType));
}

/* Save %ebx in case it's the PIC register */
static void __cpuidex(int info[4], int level, int count) {
    __asm__ __volatile__("xchg{l}\t{%%}ebx, %1\n\t"
                         "cpuid\n\t"
                         "xchg{l}\t{%%}ebx, %1\n\t"
                         : "=a"(info[0]), "=r"(info[1]), "=c"(info[2]), "=d"(info[3])
                         : "0"(level), "2"(count));
}
#endif // !ISPC_HOST_IS_WINDOWS && !__ARM__ && !__AARCH64__

#ifndef ARM_HOST
static bool __os_has_avx_support() {
#if defined(ISPC_HOST_IS_WINDOWS)
    // Check if the OS will save the YMM registers
    unsigned long long xcrFeatureMask = _xgetbv(_XCR_XFEATURE_ENABLED_MASK);
    return (xcrFeatureMask & 6) == 6;
#else  // !defined(ISPC_HOST_IS_WINDOWS)
    // Check xgetbv; this uses a .byte sequence instead of the instruction
    // directly because older assemblers do not include support for xgetbv and
    // there is no easy way to conditionally compile based on the assembler used.
    int rEAX, rEDX;
    __asm__ __volatile__(".byte 0x0f, 0x01, 0xd0" : "=a"(rEAX), "=d"(rEDX) : "c"(0));
    return (rEAX & 6) == 6;
#endif // !defined(ISPC_HOST_IS_WINDOWS)
}

static bool __os_has_avx512_support() {
#if defined(ISPC_HOST_IS_WINDOWS)
    // Check if the OS saves the XMM, YMM and ZMM registers, i.e. it supports AVX2 and AVX512.
    // See section 2.1 of software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf
    unsigned long long xcrFeatureMask = _xgetbv(_XCR_XFEATURE_ENABLED_MASK);
    return (xcrFeatureMask & 0xE6) == 0xE6;
#elif defined(ISPC_HOST_IS_APPLE)
    // macOS has different way of dealing with AVX512 than Windows and Linux:
    // - by default AVX512 is off in the newly created thread, which means CPUID flags will
    //   indicate AVX512 availability, but OS support check (XCR0) will not succeed.
    // - AVX512 can be enabled either by calling thread_set_state() or by executing any
    //   AVX512 instruction, which would cause #UD exception handled by the OS.
    // The purpose of this check is to identify if AVX512 is potentially available, so we
    // need to bypass OS check and look at CPUID flags only.
    // See ispc issue #1854 for more details.
    return true;
#else  // !defined(ISPC_HOST_IS_WINDOWS)
    // Check xgetbv; this uses a .byte sequence instead of the instruction
    // directly because older assemblers do not include support for xgetbv and
    // there is no easy way to conditionally compile based on the assembler used.
    int rEAX, rEDX;
    __asm__ __volatile__(".byte 0x0f, 0x01, 0xd0" : "=a"(rEAX), "=d"(rEDX) : "c"(0));
    return (rEAX & 0xE6) == 0xE6;
#endif // !defined(ISPC_HOST_IS_WINDOWS)
}
#endif // !ARM_HOST

static ISPCTarget lGetSystemISA() {
#ifdef ARM_HOST
    return ISPCTarget::neon_i32x4;
#else
    int info[4];
    __cpuid(info, 1);

    int info2[4];
    // Call cpuid with eax=7, ecx=0
    __cpuidex(info2, 7, 0);

    if ((info[2] & (1 << 27)) != 0 &&  // OSXSAVE
        (info2[1] & (1 << 5)) != 0 &&  // AVX2
        (info2[1] & (1 << 16)) != 0 && // AVX512 F
        __os_has_avx512_support()) {
        // We need to verify that AVX2 is also available,
        // as well as AVX512, because our targets are supposed
        // to use both.

        if ((info2[1] & (1 << 17)) != 0 && // AVX512 DQ
            (info2[1] & (1 << 28)) != 0 && // AVX512 CDI
            (info2[1] & (1 << 30)) != 0 && // AVX512 BW
            (info2[1] & (1 << 31)) != 0) { // AVX512 VL
            return ISPCTarget::avx512skx_i32x16;
        } else if ((info2[1] & (1 << 26)) != 0 && // AVX512 PF
                   (info2[1] & (1 << 27)) != 0 && // AVX512 ER
                   (info2[1] & (1 << 28)) != 0) { // AVX512 CDI
            return ISPCTarget::avx512knl_i32x16;
        }
        // If it's unknown AVX512 target, fall through and use AVX2
        // or whatever is available in the machine.
    }

    if ((info[2] & (1 << 27)) != 0 &&                           // OSXSAVE
        (info[2] & (1 << 28)) != 0 && __os_has_avx_support()) { // AVX
        // AVX1 for sure....
        // Ivy Bridge?
        if ((info[2] & (1 << 29)) != 0 && // F16C
            (info[2] & (1 << 30)) != 0 && // RDRAND
            (info2[1] & (1 << 5)) != 0) { // AVX2.
            return ISPCTarget::avx2_i32x8;
        }
        // Regular AVX
        return ISPCTarget::avx1_i32x8;
    } else if ((info[2] & (1 << 19)) != 0)
        return ISPCTarget::sse4_i32x4;
    else if ((info[3] & (1 << 26)) != 0)
        return ISPCTarget::sse2_i32x4;
    else {
        Error(SourcePos(), "Unable to detect supported SSE/AVX ISA.  Exiting.");
        exit(1);
    }
#endif
}

static const bool lIsTargetValidforArch(ISPCTarget target, Arch arch) {
    bool ret = true;
    // If target name starts with sse or avx, has to be x86 or x86-64.
    if (ISPCTargetIsX86(target)) {
        if (arch != Arch::x86_64 && arch != Arch::x86)
            ret = false;
    } else if (target == ISPCTarget::neon_i8x16 || target == ISPCTarget::neon_i16x8) {
        if (arch != Arch::arm)
            ret = false;
    } else if (target == ISPCTarget::neon_i32x4 || target == ISPCTarget::neon_i32x8) {
        if (arch != Arch::arm && arch != Arch::aarch64)
            ret = false;
    } else if (ISPCTargetIsGen(target)) {
        if (arch != Arch::genx32 && arch != Arch::genx64)
            ret = false;
    }

    return ret;
}
typedef enum {
    // Special value, indicates that no CPU is present.
    CPU_None = 0,

    // A generic 64-bit specific x86 processor model which tries to be good
    // for modern chips without enabling instruction set encodings past the
    // basic SSE2 and 64-bit ones
    CPU_x86_64 = 1,

    // Early Atom CPU. Supports SSSE3.
    CPU_Bonnell,

    // Generic Core2-like. Supports SSSE3. Isn`t quite compatible with Bonnell,
    // but for ISPC the difference is negligible; ISPC doesn`t make use of it.
    CPU_Core2,

    // Core2 Solo/Duo/Quad/Extreme. Supports SSE 4.1 (but not 4.2).
    CPU_Penryn,

    // Late Core2-like. Supports SSE 4.2 + POPCNT/LZCNT.
    CPU_Nehalem,

    // CPU in PS4/Xbox One.
    CPU_PS4,

    // Sandy Bridge. Supports AVX 1.
    CPU_SandyBridge,

    // Ivy Bridge. Supports AVX 1 + RDRAND.
    CPU_IvyBridge,

    // Haswell. Supports AVX 2.
    CPU_Haswell,

    // Broadwell. Supports AVX 2 + ADX/RDSEED/SMAP.
    CPU_Broadwell,

    // Knights Landing - Xeon Phi.
    // Supports AVX-512F: All the key AVX-512 features: masking, broadcast... ;
    //          AVX-512CDI: Conflict Detection;
    //          AVX-512ERI & PRI: 28-bit precision RCP, RSQRT and EXP transcendentals,
    //                            new prefetch instructions.
    CPU_KNL,
    // Skylake Xeon.
    // Supports AVX-512F: All the key AVX-512 features: masking, broadcast... ;
    //          AVX-512CDI: Conflict Detection;
    //          AVX-512VL: Vector Length Orthogonality;
    //          AVX-512DQ: New HPC ISA (vs AVX512F);
    //          AVX-512BW: Byte and Word Support.
    CPU_SKX,

    // Icelake client
    CPU_ICL,

    // Late Atom-like design. Supports SSE 4.2 + POPCNT/LZCNT.
    CPU_Silvermont,

    CPU_ICX,
#if ISPC_LLVM_VERSION >= ISPC_LLVM_10_0
    CPU_TGL,
#endif
#if ISPC_LLVM_VERSION >= ISPC_LLVM_12_0
    CPU_ADL,
    CPU_SPR,
#endif

// FIXME: LLVM supports a ton of different ARM CPU variants--not just
// cortex-a9 and a15.  We should be able to handle any of them that also
// have NEON support.
#ifdef ISPC_ARM_ENABLED
    // ARM Cortex A9. Supports NEON VFPv3.
    CPU_CortexA9,

    // ARM Cortex A15. Supports NEON VFPv4.
    CPU_CortexA15,

    // ARM Cortex A35, A53, A57.
    CPU_CortexA35,
    CPU_CortexA53,
    CPU_CortexA57,
#endif
#ifdef ISPC_GENX_ENABLED
    CPU_GENX,
    CPU_GENX_TGLLP,
#endif
    sizeofCPUtype
} CPUtype;

class AllCPUs {
  private:
    std::vector<std::vector<std::string>> names;
    std::vector<std::set<CPUtype>> compat;

    std::set<CPUtype> Set(int type, ...) {
        std::set<CPUtype> retn;
        va_list args;

        retn.insert((CPUtype)type);
        va_start(args, type);
        while ((type = va_arg(args, int)) != CPU_None)
            retn.insert((CPUtype)type);
        va_end(args);

        return retn;
    }

  public:
    AllCPUs() {
        names = std::vector<std::vector<std::string>>(sizeofCPUtype);
        compat = std::vector<std::set<CPUtype>>(sizeofCPUtype);

        names[CPU_None].push_back("");

        names[CPU_x86_64].push_back("x86-64");

        names[CPU_Bonnell].push_back("atom");
        names[CPU_Bonnell].push_back("bonnell");

        names[CPU_Core2].push_back("core2");

        names[CPU_Penryn].push_back("penryn");

        names[CPU_Silvermont].push_back("slm");
        names[CPU_Silvermont].push_back("silvermont");

        names[CPU_Nehalem].push_back("corei7");
        names[CPU_Nehalem].push_back("nehalem");

        names[CPU_PS4].push_back("btver2");
        names[CPU_PS4].push_back("ps4");

        names[CPU_SandyBridge].push_back("corei7-avx");
        names[CPU_SandyBridge].push_back("sandybridge");

        names[CPU_IvyBridge].push_back("core-avx-i");
        names[CPU_IvyBridge].push_back("ivybridge");

        names[CPU_Haswell].push_back("core-avx2");
        names[CPU_Haswell].push_back("haswell");

        names[CPU_Broadwell].push_back("broadwell");

        names[CPU_KNL].push_back("knl");

        names[CPU_SKX].push_back("skx");

        names[CPU_ICL].push_back("icelake-client");
        names[CPU_ICL].push_back("icl");

        names[CPU_ICX].push_back("icelake-server");
        names[CPU_ICX].push_back("icx");
#if ISPC_LLVM_VERSION >= ISPC_LLVM_10_0
        names[CPU_TGL].push_back("tigerlake");
        names[CPU_TGL].push_back("tgl");
#endif
#if ISPC_LLVM_VERSION >= ISPC_LLVM_12_0
        names[CPU_ADL].push_back("alderlake");
        names[CPU_ADL].push_back("adl");
        names[CPU_SPR].push_back("sapphirerapids");
        names[CPU_SPR].push_back("spr");
#endif

#ifdef ISPC_ARM_ENABLED
        names[CPU_CortexA9].push_back("cortex-a9");

        names[CPU_CortexA15].push_back("cortex-a15");

        names[CPU_CortexA35].push_back("cortex-a35");

        names[CPU_CortexA53].push_back("cortex-a53");

        names[CPU_CortexA57].push_back("cortex-a57");
#endif

#ifdef ISPC_GENX_ENABLED
        names[CPU_GENX].push_back("SKL");
        names[CPU_GENX_TGLLP].push_back("TGLLP");
        names[CPU_GENX_TGLLP].push_back("DG1");
#endif

        Assert(names.size() == sizeofCPUtype);

        compat[CPU_Silvermont] =
            Set(CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont, CPU_None);

        compat[CPU_KNL] = Set(CPU_KNL, CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                              CPU_SandyBridge, CPU_IvyBridge, CPU_Haswell, CPU_Broadwell, CPU_None);

        compat[CPU_SKX] = Set(CPU_SKX, CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                              CPU_SandyBridge, CPU_IvyBridge, CPU_Haswell, CPU_Broadwell, CPU_None);
#if ISPC_LLVM_VERSION >= ISPC_LLVM_12_0
        compat[CPU_SPR] =
            Set(CPU_SPR, CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont, CPU_SandyBridge,
                CPU_IvyBridge, CPU_Haswell, CPU_Broadwell, CPU_SKX, CPU_ICL, CPU_ICX, CPU_TGL, CPU_ADL, CPU_None);
        compat[CPU_ADL] = Set(CPU_ADL, CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                              CPU_SandyBridge, CPU_IvyBridge, CPU_Haswell, CPU_Broadwell, CPU_None);
#endif
#if ISPC_LLVM_VERSION >= ISPC_LLVM_10_0
        compat[CPU_TGL] =
            Set(CPU_TGL, CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont, CPU_SandyBridge,
                CPU_IvyBridge, CPU_Haswell, CPU_Broadwell, CPU_SKX, CPU_ICL, CPU_ICX, CPU_None);
#endif
        compat[CPU_ICX] = Set(CPU_ICX, CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                              CPU_SandyBridge, CPU_IvyBridge, CPU_Haswell, CPU_Broadwell, CPU_SKX, CPU_ICL, CPU_None);

        compat[CPU_ICL] = Set(CPU_ICL, CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                              CPU_SandyBridge, CPU_IvyBridge, CPU_Haswell, CPU_Broadwell, CPU_SKX, CPU_None);

        compat[CPU_Broadwell] = Set(CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                                    CPU_SandyBridge, CPU_IvyBridge, CPU_Haswell, CPU_Broadwell, CPU_None);
        compat[CPU_Haswell] = Set(CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                                  CPU_SandyBridge, CPU_IvyBridge, CPU_Haswell, CPU_Broadwell, CPU_None);
        compat[CPU_IvyBridge] = Set(CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                                    CPU_SandyBridge, CPU_IvyBridge, CPU_None);
        compat[CPU_SandyBridge] =
            Set(CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont, CPU_SandyBridge, CPU_None);
        compat[CPU_PS4] = Set(CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                              CPU_SandyBridge, CPU_PS4, CPU_None);
        compat[CPU_Nehalem] =
            Set(CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont, CPU_None);
        compat[CPU_Penryn] = Set(CPU_x86_64, CPU_Bonnell, CPU_Penryn, CPU_Core2, CPU_Nehalem, CPU_Silvermont, CPU_None);
        compat[CPU_Core2] = Set(CPU_x86_64, CPU_Bonnell, CPU_Core2, CPU_None);
        compat[CPU_Bonnell] = Set(CPU_x86_64, CPU_Bonnell, CPU_Core2, CPU_None);

        compat[CPU_x86_64] = Set(CPU_x86_64, CPU_None);

#ifdef ISPC_ARM_ENABLED
        compat[CPU_CortexA15] = Set(CPU_CortexA9, CPU_CortexA15, CPU_None);
        compat[CPU_CortexA9] = Set(CPU_CortexA9, CPU_None);
        compat[CPU_CortexA35] = Set(CPU_CortexA35, CPU_None);
        compat[CPU_CortexA53] = Set(CPU_CortexA53, CPU_None);
        compat[CPU_CortexA57] = Set(CPU_CortexA57, CPU_None);
#endif

#ifdef ISPC_GENX_ENABLED
        compat[CPU_GENX] = Set(CPU_GENX, CPU_None);
        compat[CPU_GENX_TGLLP] = Set(CPU_GENX_TGLLP, CPU_GENX, CPU_None);
#endif
    }

    std::string HumanReadableListOfNames() {
        std::stringstream CPUs;
        for (int i = CPU_x86_64; i < sizeofCPUtype; i++) {
            CPUs << names[i][0];
            if (names[i].size() > 1) {
                CPUs << " (synonyms: " << names[i][1];
                for (int j = 2, je = names[i].size(); j < je; j++)
                    CPUs << ", " << names[i][j];
                CPUs << ")";
            }
            if (i < sizeofCPUtype - 1)
                CPUs << ", ";
        }
        return CPUs.str();
    }

    std::string &GetDefaultNameFromType(CPUtype type) {
        Assert((type >= CPU_None) && (type < sizeofCPUtype));
        return names[type][0];
    }

    CPUtype GetTypeFromName(std::string name) {
        CPUtype retn = CPU_None;

        for (int i = 1; (retn == CPU_None) && (i < sizeofCPUtype); i++)
            for (int j = 0, je = names[i].size(); (retn == CPU_None) && (j < je); j++)
                if (!name.compare(names[i][j]))
                    retn = (CPUtype)i;
        return retn;
    }

    bool BackwardCompatible(CPUtype what, CPUtype with) {
        Assert((what > CPU_None) && (what < sizeofCPUtype));
        Assert((with > CPU_None) && (with < sizeofCPUtype));
        return compat[what].find(with) != compat[what].end();
    }
};

Target::Target(Arch arch, const char *cpu, ISPCTarget ispc_target, bool pic, bool printTarget)
    : m_target(NULL), m_targetMachine(NULL), m_dataLayout(NULL), m_valid(false), m_ispc_target(ispc_target),
      m_isa(SSE2), m_arch(Arch::none), m_is32Bit(true), m_cpu(""), m_attributes(""), m_tf_attributes(NULL),
      m_nativeVectorWidth(-1), m_nativeVectorAlignment(-1), m_dataTypeWidth(-1), m_vectorWidth(-1), m_generatePIC(pic),
      m_maskingIsFree(false), m_maskBitCount(-1), m_hasHalf(false), m_hasRand(false), m_hasGather(false),
      m_hasScatter(false), m_hasTranscendentals(false), m_hasTrigonometry(false), m_hasRsqrtd(false), m_hasRcpd(false),
      m_hasVecPrefetch(false), m_hasSaturatingArithmetic(false), m_hasFp64Support(true) {
    CPUtype CPUID = CPU_None, CPUfromISA = CPU_None;
    AllCPUs a;
    std::string featuresString;

    if (cpu) {
        CPUID = a.GetTypeFromName(cpu);
        if (CPUID == CPU_None) {
            Error(SourcePos(),
                  "Error: CPU type \"%s\" unknown. Supported"
                  " CPUs: %s.",
                  cpu, a.HumanReadableListOfNames().c_str());
            return;
        }
    }

    if (m_ispc_target == ISPCTarget::none) {
        // If a CPU was specified explicitly, try to pick the best
        // possible ISA based on that.
        switch (CPUID) {
        case CPU_None: {
            // No CPU and no ISA, so use system info to figure out
            // what this CPU supports.
            m_ispc_target = lGetSystemISA();
            std::string target_string = ISPCTargetToString(m_ispc_target);
            Warning(SourcePos(),
                    "No --target specified on command-line."
                    " Using default system target \"%s\".",
                    target_string.c_str());
            break;
        }

#ifdef ISPC_ARM_ENABLED
        case CPU_CortexA9:
        case CPU_CortexA15:
        case CPU_CortexA35:
        case CPU_CortexA53:
        case CPU_CortexA57:
            m_ispc_target = ISPCTarget::neon_i32x4;
            break;
#endif

#ifdef ISPC_GENX_ENABLED
        case CPU_GENX:
            m_ispc_target = ISPCTarget::genx_x16;
            break;
        case CPU_GENX_TGLLP:
            m_ispc_target = ISPCTarget::genx_x16;
            break;
#endif

        case CPU_KNL:
            m_ispc_target = ISPCTarget::avx512knl_i32x16;
            break;

#if ISPC_LLVM_VERSION >= ISPC_LLVM_12_0
        case CPU_SPR:
#endif
#if ISPC_LLVM_VERSION >= ISPC_LLVM_10_0
        case CPU_TGL:
#endif
        case CPU_ICX:
        case CPU_ICL:
        case CPU_SKX:
            m_ispc_target = ISPCTarget::avx512skx_i32x16;
            break;

#if ISPC_LLVM_VERSION >= ISPC_LLVM_12_0
        case CPU_ADL:
#endif
        case CPU_Broadwell:
        case CPU_Haswell:
            m_ispc_target = ISPCTarget::avx2_i32x8;
            break;

        case CPU_IvyBridge:
        case CPU_SandyBridge:
            m_ispc_target = ISPCTarget::avx1_i32x8;
            break;

            // Penryn is here because ISPC does not use SSE 4.2
        case CPU_Penryn:
        case CPU_Nehalem:
        case CPU_Silvermont:
            m_ispc_target = ISPCTarget::sse4_i32x4;
            break;

        case CPU_PS4:
            m_ispc_target = ISPCTarget::avx1_i32x4;
            break;

        default:
            m_ispc_target = ISPCTarget::sse2_i32x4;
            break;
        }
        if (CPUID != CPU_None) {
            std::string target_string = ISPCTargetToString(m_ispc_target);
            Warning(SourcePos(),
                    "No --target specified on command-line."
                    " Using ISA \"%s\" based on specified CPU \"%s\".",
                    target_string.c_str(), cpu);
        }
    }

    if (m_ispc_target == ISPCTarget::host) {
        m_ispc_target = lGetSystemISA();
    }

    if (arch == Arch::none) {
#ifdef ISPC_ARM_ENABLED
        if (ISPCTargetIsNeon(m_ispc_target)) {
#if defined(__arm__)
            arch = Arch::arm;
#else
            arch = Arch::aarch64;
#endif
        } else
#endif
#if ISPC_GENX_ENABLED
            if (ISPCTargetIsGen(m_ispc_target)) {
            arch = Arch::genx64;
        } else
#endif
            arch = Arch::x86_64;
    }

    bool error = false;
    // Make sure the target architecture is a known one; print an error
    // with the valid ones otherwise.
    for (llvm::TargetRegistry::iterator iter = llvm::TargetRegistry::targets().begin();
         iter != llvm::TargetRegistry::targets().end(); ++iter) {
        if (ArchToString(arch) == iter->getName()) {
            this->m_target = &*iter;
            break;
        }
    }
    // For gen target we do not need to create target/targetMachine
    if (this->m_target == NULL && !ISPCTargetIsGen(m_ispc_target)) {
        std::string error_message;
        error_message = "Invalid architecture \"";
        error_message += ArchToString(arch);
        error_message += "\"\nOptions: ";
        llvm::TargetRegistry::iterator iter;
        const char *separator = "";
        for (iter = llvm::TargetRegistry::targets().begin(); iter != llvm::TargetRegistry::targets().end(); ++iter) {
            error_message += separator;
            error_message += iter->getName();
            separator = ", ";
        }
        error_message += ".";
        Error(SourcePos(), "%s", error_message.c_str());
        error = true;
    } else {
        this->m_arch = arch;
    }

    // Ensure that we have a valid target/arch combination.
    if (!lIsTargetValidforArch(m_ispc_target, arch)) {
        std::string str_arch = ArchToString(arch);
        std::string target_string = ISPCTargetToString(m_ispc_target);
        Error(SourcePos(), "arch = %s and target = %s is not a valid combination.", str_arch.c_str(),
              target_string.c_str());
        return;
    }
#ifdef ISPC_GENX_ENABLED
    if ((ISPCTargetIsGen(m_ispc_target)) && (CPUID == CPU_GENX_TGLLP)) {
        m_hasFp64Support = false;
    }
    // In case of gen target addressing should correspond to host addressing. Otherwise SVM pointers will not work.
    if (arch == Arch::genx32) {
        g->opt.force32BitAddressing = true;
    } else if (arch == Arch::genx64) {
        g->opt.force32BitAddressing = false;
    }
#endif
    // Check default LLVM generated targets
    bool unsupported_target = false;
    switch (m_ispc_target) {
    case ISPCTarget::sse2_i32x4:
        this->m_isa = Target::SSE2;
        this->m_nativeVectorWidth = 4;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 4;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        CPUfromISA = CPU_x86_64;
        break;
    case ISPCTarget::sse2_i32x8:
        this->m_isa = Target::SSE2;
        this->m_nativeVectorWidth = 4;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 8;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        CPUfromISA = CPU_Core2;
        break;
    case ISPCTarget::sse4_i8x16:
        this->m_isa = Target::SSE4;
        this->m_nativeVectorWidth = 16;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 8;
        this->m_vectorWidth = 16;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 8;
        CPUfromISA = CPU_Nehalem;
        break;
    case ISPCTarget::sse4_i16x8:
        this->m_isa = Target::SSE4;
        this->m_nativeVectorWidth = 8;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 16;
        this->m_vectorWidth = 8;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 16;
        CPUfromISA = CPU_Nehalem;
        break;
    case ISPCTarget::sse4_i32x4:
        this->m_isa = Target::SSE4;
        this->m_nativeVectorWidth = 4;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 4;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        CPUfromISA = CPU_Nehalem;
        break;
    case ISPCTarget::sse4_i32x8:
        this->m_isa = Target::SSE4;
        this->m_nativeVectorWidth = 4;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 8;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        CPUfromISA = CPU_Nehalem;
        break;
    case ISPCTarget::avx1_i32x4:
        this->m_isa = Target::AVX;
        this->m_nativeVectorWidth = 8;
        this->m_nativeVectorAlignment = 32;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 4;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        CPUfromISA = CPU_SandyBridge;
        break;
    case ISPCTarget::avx1_i32x8:
        this->m_isa = Target::AVX;
        this->m_nativeVectorWidth = 8;
        this->m_nativeVectorAlignment = 32;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 8;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        CPUfromISA = CPU_SandyBridge;
        break;
    case ISPCTarget::avx1_i32x16:
        this->m_isa = Target::AVX;
        this->m_nativeVectorWidth = 8;
        this->m_nativeVectorAlignment = 32;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 16;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        CPUfromISA = CPU_SandyBridge;
        break;
    case ISPCTarget::avx1_i64x4:
        this->m_isa = Target::AVX;
        this->m_nativeVectorWidth = 8; /* native vector width in terms of floats */
        this->m_nativeVectorAlignment = 32;
        this->m_dataTypeWidth = 64;
        this->m_vectorWidth = 4;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 64;
        CPUfromISA = CPU_SandyBridge;
        break;
    case ISPCTarget::avx2_i8x32:
        this->m_isa = Target::AVX2;
        this->m_nativeVectorWidth = 32;
        this->m_nativeVectorAlignment = 32;
        this->m_dataTypeWidth = 8;
        this->m_vectorWidth = 32;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 8;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = true;
        CPUfromISA = CPU_Haswell;
        break;
    case ISPCTarget::avx2_i16x16:
        this->m_isa = Target::AVX2;
        this->m_nativeVectorWidth = 16;
        this->m_nativeVectorAlignment = 32;
        this->m_dataTypeWidth = 16;
        this->m_vectorWidth = 16;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 16;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = true;
        CPUfromISA = CPU_Haswell;
        break;
    case ISPCTarget::avx2_i32x4:
        this->m_isa = Target::AVX2;
        this->m_nativeVectorWidth = 8;
        this->m_nativeVectorAlignment = 32;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 4;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = true;
        CPUfromISA = CPU_Haswell;
        break;
    case ISPCTarget::avx2_i32x8:
        this->m_isa = Target::AVX2;
        this->m_nativeVectorWidth = 8;
        this->m_nativeVectorAlignment = 32;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 8;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = true;
        CPUfromISA = CPU_Haswell;
        break;
    case ISPCTarget::avx2_i32x16:
        this->m_isa = Target::AVX2;
        this->m_nativeVectorWidth = 16;
        this->m_nativeVectorAlignment = 32;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 16;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = true;
        CPUfromISA = CPU_Haswell;
        break;
    case ISPCTarget::avx2_i64x4:
        this->m_isa = Target::AVX2;
        this->m_nativeVectorWidth = 8; /* native vector width in terms of floats */
        this->m_nativeVectorAlignment = 32;
        this->m_dataTypeWidth = 64;
        this->m_vectorWidth = 4;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 64;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = true;
        CPUfromISA = CPU_Haswell;
        break;
    case ISPCTarget::avx512knl_i32x16:
        this->m_isa = Target::KNL_AVX512;
        this->m_nativeVectorWidth = 16;
        this->m_nativeVectorAlignment = 64;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 16;
        this->m_maskingIsFree = true;
        this->m_maskBitCount = 1;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = this->m_hasScatter = true;
        this->m_hasTranscendentals = false;
        // For MIC it is set to true due to performance reasons. The option should be tested.
        this->m_hasTrigonometry = false;
        this->m_hasRsqrtd = this->m_hasRcpd = false;
        this->m_hasVecPrefetch = false;
        CPUfromISA = CPU_KNL;
        break;
    case ISPCTarget::avx512skx_i32x8:
        this->m_isa = Target::SKX_AVX512;
        this->m_nativeVectorWidth = 16;
        this->m_nativeVectorAlignment = 64;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 8;
        this->m_maskingIsFree = true;
        this->m_maskBitCount = 1;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = this->m_hasScatter = true;
        this->m_hasTranscendentals = false;
        this->m_hasTrigonometry = false;
        this->m_hasRsqrtd = this->m_hasRcpd = false;
        this->m_hasVecPrefetch = false;
        CPUfromISA = CPU_SKX;
        this->m_funcAttributes.push_back(std::make_pair("prefer-vector-width", "256"));
        this->m_funcAttributes.push_back(std::make_pair("min-legal-vector-width", "256"));
        break;
    case ISPCTarget::avx512skx_i32x16:
        this->m_isa = Target::SKX_AVX512;
        this->m_nativeVectorWidth = 16;
        this->m_nativeVectorAlignment = 64;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 16;
        this->m_maskingIsFree = true;
        this->m_maskBitCount = 1;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = this->m_hasScatter = true;
        this->m_hasTranscendentals = false;
        this->m_hasTrigonometry = false;
        this->m_hasRsqrtd = this->m_hasRcpd = false;
        this->m_hasVecPrefetch = false;
        CPUfromISA = CPU_SKX;
        if (g->opt.disableZMM) {
            this->m_funcAttributes.push_back(std::make_pair("prefer-vector-width", "256"));
            this->m_funcAttributes.push_back(std::make_pair("min-legal-vector-width", "256"));
        } else {
            this->m_funcAttributes.push_back(std::make_pair("prefer-vector-width", "512"));
            this->m_funcAttributes.push_back(std::make_pair("min-legal-vector-width", "512"));
        }
        break;
    case ISPCTarget::avx512skx_i8x64:
#if ISPC_LLVM_VERSION >= ISPC_LLVM_10_0 // LLVM 10.0+
        // This target is enabled only for LLVM 10.0 and later
        // because LLVM requires a number of fixes, which are
        // committed to LLVM 11.0 and can be applied to 10.0, but not
        // earlier versions.
        this->m_isa = Target::SKX_AVX512;
        this->m_nativeVectorWidth = 64;
        this->m_nativeVectorAlignment = 64;
        this->m_dataTypeWidth = 8;
        this->m_vectorWidth = 64;
        this->m_maskingIsFree = true;
        this->m_maskBitCount = 1;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = this->m_hasScatter = true;
        this->m_hasTranscendentals = false;
        this->m_hasTrigonometry = false;
        this->m_hasRsqrtd = this->m_hasRcpd = false;
        this->m_hasVecPrefetch = false;
        CPUfromISA = CPU_SKX;
        break;
#else
        unsupported_target = true;
        break;
#endif
    case ISPCTarget::avx512skx_i16x32:
#if ISPC_LLVM_VERSION >= ISPC_LLVM_10_0 // LLVM 10.0+
        // This target is enabled only for LLVM 10.0 and later
        // because LLVM requires a number of fixes, which are
        // committed to LLVM 11.0 and can be applied to 10.0, but not
        // earlier versions.
        this->m_isa = Target::SKX_AVX512;
        this->m_nativeVectorWidth = 64;
        this->m_nativeVectorAlignment = 64;
        this->m_dataTypeWidth = 16;
        this->m_vectorWidth = 32;
        this->m_maskingIsFree = true;
        this->m_maskBitCount = 1;
        this->m_hasHalf = true;
        this->m_hasRand = true;
        this->m_hasGather = this->m_hasScatter = true;
        this->m_hasTranscendentals = false;
        this->m_hasTrigonometry = false;
        this->m_hasRsqrtd = this->m_hasRcpd = false;
        this->m_hasVecPrefetch = false;
        CPUfromISA = CPU_SKX;
        break;
#else
        unsupported_target = true;
        break;
#endif
#ifdef ISPC_ARM_ENABLED
    case ISPCTarget::neon_i8x16:
        this->m_isa = Target::NEON;
        this->m_nativeVectorWidth = 16;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 8;
        this->m_vectorWidth = 16;
        this->m_hasHalf = true; // ??
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 8;
        break;
    case ISPCTarget::neon_i16x8:
        this->m_isa = Target::NEON;
        this->m_nativeVectorWidth = 8;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 16;
        this->m_vectorWidth = 8;
        this->m_hasHalf = true; // ??
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 16;
        break;
    case ISPCTarget::neon_i32x4:
        this->m_isa = Target::NEON;
        this->m_nativeVectorWidth = 4;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 4;
        this->m_hasHalf = true; // ??
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        break;
    case ISPCTarget::neon_i32x8:
        this->m_isa = Target::NEON;
        this->m_nativeVectorWidth = 4;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 8;
        this->m_hasHalf = true; // ??
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        break;
#else
    case ISPCTarget::neon_i8x16:
    case ISPCTarget::neon_i16x8:
    case ISPCTarget::neon_i32x4:
    case ISPCTarget::neon_i32x8:
        unsupported_target = true;
        break;
#endif
#ifdef ISPC_WASM_ENABLED
    case ISPCTarget::wasm_i32x4:
        this->m_isa = Target::WASM;
        this->m_nativeVectorWidth = 4;
        this->m_nativeVectorAlignment = 16;
        this->m_dataTypeWidth = 32;
        this->m_vectorWidth = 4;
        this->m_hasHalf = false;
        this->m_maskingIsFree = false;
        this->m_maskBitCount = 32;
        this->m_hasTranscendentals = false;
        this->m_hasTrigonometry = false;
        this->m_hasRcpd = false;
        this->m_hasRsqrtd = false;
        this->m_hasScatter = false;
        this->m_hasGather = false;
        this->m_hasVecPrefetch = false;
        break;
#else
    case ISPCTarget::wasm_i32x4:
        unsupported_target = true;
        break;
#endif
#ifdef ISPC_GENX_ENABLED
    case ISPCTarget::genx_x8:
        this->m_isa = Target::GENX;
        this->m_nativeVectorWidth = 8;
        this->m_nativeVectorAlignment = 64;
        this->m_vectorWidth = 8;
        this->m_dataTypeWidth = 32;
        this->m_hasHalf = true;
        this->m_maskingIsFree = true;
        this->m_maskBitCount = 1;
        this->m_hasSaturatingArithmetic = true;
        this->m_hasTranscendentals = true;
        this->m_hasTrigonometry = true;
        this->m_hasGather = this->m_hasScatter = true;
        CPUfromISA = CPU_GENX;
        break;
    case ISPCTarget::genx_x16:
        this->m_isa = Target::GENX;
        this->m_nativeVectorWidth = 16;
        this->m_nativeVectorAlignment = 64;
        this->m_vectorWidth = 16;
        this->m_dataTypeWidth = 32;
        this->m_hasHalf = true;
        this->m_maskingIsFree = true;
        this->m_maskBitCount = 1;
        this->m_hasSaturatingArithmetic = true;
        this->m_hasTranscendentals = true;
        this->m_hasTrigonometry = true;
        this->m_hasGather = this->m_hasScatter = true;
        CPUfromISA = CPU_GENX;
        break;
#else
    case ISPCTarget::genx_x8:
    case ISPCTarget::genx_x16:
        unsupported_target = true;
        break;
#endif
    case ISPCTarget::none:
    case ISPCTarget::host:
    case ISPCTarget::error:
        unsupported_target = true;
        break;
    }

    if (unsupported_target) {
        // Hitting one of unsupported targets is internal error.
        // Proper reporting about incorrect targets is done during options parsing.
        std::string target_string = "Problem with target (" + ISPCTargetToString(m_ispc_target) + ")";
        FATAL(target_string.c_str());
    }

#if defined(ISPC_ARM_ENABLED)
    if ((CPUID == CPU_None) && ISPCTargetIsNeon(m_ispc_target)) {
        if (arch == Arch::arm) {
            CPUID = CPU_CortexA9;
        } else if (arch == Arch::aarch64) {
            CPUID = CPU_CortexA35;
        } else {
            UNREACHABLE();
        }
    }
#endif

    if (CPUID == CPU_None) {
        cpu = a.GetDefaultNameFromType(CPUfromISA).c_str();
    } else {
        if ((CPUfromISA != CPU_None) && !a.BackwardCompatible(CPUID, CPUfromISA)) {
            std::string target_string = ISPCTargetToString(m_ispc_target);
            Error(SourcePos(),
                  "The requested CPU (%s) is incompatible"
                  " with the CPU required for %s target (%s)",
                  cpu, target_string.c_str(), a.GetDefaultNameFromType(CPUfromISA).c_str());
            return;
        }
        cpu = a.GetDefaultNameFromType(CPUID).c_str();
    }
    this->m_cpu = cpu;

    if (!error) {
        // Create TargetMachine
        std::string triple = GetTripleString();

        // The last validity check to ensure that supported for this target was enabled in the build.
        if (!g->target_registry->isSupported(m_ispc_target, g->target_os, arch)) {
            std::string target_string = ISPCTargetToString(m_ispc_target);
            std::string arch_str = ArchToString(arch);
            std::string os_str = OSToString(g->target_os);
            Error(SourcePos(), "%s target for %s on %s is not supported in current build.", target_string.c_str(),
                  arch_str.c_str(), os_str.c_str());
            return;
        }

        llvm::Optional<llvm::Reloc::Model> relocModel;
        if (m_generatePIC) {
            relocModel = llvm::Reloc::PIC_;
        }
        llvm::TargetOptions options;
#ifdef ISPC_ARM_ENABLED
        options.FloatABIType = llvm::FloatABI::Hard;
        if (arch == Arch::arm) {
            if (g->target_os == TargetOS::custom_linux) {
                this->m_funcAttributes.push_back(std::make_pair("target-features", "+crypto,+fp-armv8,+neon,+sha2"));
            } else {
                this->m_funcAttributes.push_back(std::make_pair("target-features", "+neon,+fp16"));
            }
            featuresString = "+neon,+fp16";
        } else if (arch == Arch::aarch64) {
            if (g->target_os == TargetOS::custom_linux) {
                this->m_funcAttributes.push_back(
                    std::make_pair("target-features", "+aes,+crc,+crypto,+fp-armv8,+neon,+sha2"));
            } else {
                this->m_funcAttributes.push_back(std::make_pair("target-features", "+neon"));
            }
            featuresString = "+neon";
        }
#endif

        // Support 'i64' and 'double' types in cm
        if (isGenXTarget())
            featuresString += "+longlong";

        if (g->opt.disableFMA == false)
            options.AllowFPOpFusion = llvm::FPOpFusion::Fast;

        // For gen target we do not need to create target/targetMachine
        if (!isGenXTarget()) {
            m_targetMachine = m_target->createTargetMachine(triple, m_cpu, featuresString, options, relocModel);
            Assert(m_targetMachine != NULL);

            // Set Optimization level for llvm codegen based on Optimization level
            // requested by user via ISPC Optimization Flag. Mapping is :
            // ISPC O0 -> Codegen O0
            // ISPC O1,O2,O3,default -> Codegen O3
            llvm::CodeGenOpt::Level cOptLevel = llvm::CodeGenOpt::Level::Aggressive;
            switch (g->codegenOptLevel) {
            case Globals::CodegenOptLevel::None:
                cOptLevel = llvm::CodeGenOpt::Level::None;
                break;

            case Globals::CodegenOptLevel::Aggressive:
                cOptLevel = llvm::CodeGenOpt::Level::Aggressive;
                break;
            }
            m_targetMachine->setOptLevel(cOptLevel);

            m_targetMachine->Options.MCOptions.AsmVerbose = true;

            // Change default version of generated DWARF.
            if (g->generateDWARFVersion != 0) {
                m_targetMachine->Options.MCOptions.DwarfVersion = g->generateDWARFVersion;
            }
        }
        // Initialize TargetData/DataLayout in 3 steps.
        // 1. Get default data layout first
        std::string dl_string;
        if (m_targetMachine != NULL)
            dl_string = m_targetMachine->createDataLayout().getStringRepresentation();
        if (isGenXTarget())
            dl_string = m_arch == Arch::genx64 ? "e-p:64:64-i64:64-n8:16:32" : "e-p:32:32-i64:64-n8:16:32";

        // 2. Finally set member data
        m_dataLayout = new llvm::DataLayout(dl_string);

        // Set is32Bit
        // This indicates if we are compiling for 32 bit platform and can assume 32 bit runtime.

        this->m_is32Bit = (getDataLayout()->getPointerSize() == 4);

        // TO-DO : Revisit addition of "target-features" and "target-cpu" for ARM support.
        llvm::AttrBuilder fattrBuilder;
#ifdef ISPC_ARM_ENABLED
        if (m_isa == Target::NEON)
            fattrBuilder.addAttribute("target-cpu", this->m_cpu);
#endif
        for (auto const &f_attr : m_funcAttributes)
            fattrBuilder.addAttribute(f_attr.first, f_attr.second);
        this->m_tf_attributes = new llvm::AttrBuilder(fattrBuilder);

        Assert(this->m_vectorWidth <= ISPC_MAX_NVEC);
    }

    m_valid = !error;

    if (printTarget) {
        if (!isGenXTarget()) {
            printf("Target Triple: %s\n", m_targetMachine->getTargetTriple().str().c_str());
            printf("Target CPU: %s\n", m_targetMachine->getTargetCPU().str().c_str());
            printf("Target Feature String: %s\n", m_targetMachine->getTargetFeatureString().str().c_str());
        } else {
            printf("Target Triple: %s\n", this->GetTripleString().c_str());
            printf("Target GPU: %s\n", this->getCPU().c_str());
            printf("Target Feature String: %s\n", featuresString.c_str());
        }
    }

    return;
}

std::string Target::SupportedCPUs() {
    AllCPUs a;
    return a.HumanReadableListOfNames();
}

std::string Target::GetTripleString() const {
    llvm::Triple triple;
    switch (g->target_os) {
    case TargetOS::windows:
        if (m_arch == Arch::x86) {
            triple.setArchName("i686");
        } else if (m_arch == Arch::x86_64) {
            triple.setArchName("x86_64");
        } else if (m_arch == Arch::arm) {
            Error(SourcePos(), "Arm is not supported on Windows.");
            exit(1);
        } else if (m_arch == Arch::aarch64) {
            Error(SourcePos(), "Aarch64 is not supported on Windows.");
            exit(1);
        } else if (m_arch == Arch::genx32) {
            triple.setArchName("spir");
        } else if (m_arch == Arch::genx64) {
            triple.setArchName("spir64");
        } else {
            Error(SourcePos(), "Unknown arch.");
            exit(1);
        }
#ifdef ISPC_GENX_ENABLED
        if (m_arch == Arch::genx32 || m_arch == Arch::genx64) {
            //"spir64-unknown-unknown"
            triple.setVendor(llvm::Triple::VendorType::UnknownVendor);
            triple.setOS(llvm::Triple::OSType::UnknownOS);
            return triple.str();
        }
#endif
        //"x86_64-pc-windows-msvc"
        triple.setVendor(llvm::Triple::VendorType::PC);
        triple.setOS(llvm::Triple::OSType::Win32);
        triple.setEnvironment(llvm::Triple::EnvironmentType::MSVC);
        break;
    case TargetOS::custom_linux:
    case TargetOS::linux:
        if (m_arch == Arch::x86) {
            triple.setArchName("i686");
        } else if (m_arch == Arch::x86_64) {
            triple.setArchName("x86_64");
        } else if (m_arch == Arch::arm) {
            triple.setArchName("armv7");
        } else if (m_arch == Arch::aarch64) {
            triple.setArchName("aarch64");
        } else if (m_arch == Arch::genx32) {
            triple.setArchName("spir");
        } else if (m_arch == Arch::genx64) {
            triple.setArchName("spir64");
        } else {
            Error(SourcePos(), "Unknown arch.");
            exit(1);
        }
#ifdef ISPC_GENX_ENABLED
        if (m_arch == Arch::genx32 || m_arch == Arch::genx64) {
            //"spir64-unknown-unknown"
            triple.setVendor(llvm::Triple::VendorType::UnknownVendor);
            triple.setOS(llvm::Triple::OSType::UnknownOS);
            return triple.str();
        }
#endif
        triple.setVendor(llvm::Triple::VendorType::UnknownVendor);
        triple.setOS(llvm::Triple::OSType::Linux);
        if (m_arch == Arch::x86 || m_arch == Arch::x86_64 || m_arch == Arch::aarch64 || m_arch == Arch::genx32 ||
            m_arch == Arch::genx64) {
            triple.setEnvironment(llvm::Triple::EnvironmentType::GNU);
        } else if (m_arch == Arch::arm) {
            triple.setEnvironment(llvm::Triple::EnvironmentType::GNUEABIHF);
        } else {
            Error(SourcePos(), "Unknown arch.");
            exit(1);
        }
        break;
    case TargetOS::freebsd:
        if (m_arch == Arch::x86) {
            triple.setArchName("i686");
        } else if (m_arch == Arch::x86_64) {
            triple.setArchName("amd64");
        } else if (m_arch == Arch::arm) {
            triple.setArchName("armv7");
        } else if (m_arch == Arch::aarch64) {
            triple.setArchName("aarch64");
        } else {
            Error(SourcePos(), "Unknown arch.");
            exit(1);
        }
        triple.setVendor(llvm::Triple::VendorType::UnknownVendor);
        triple.setOS(llvm::Triple::OSType::FreeBSD);
        break;
    case TargetOS::macos:
        // asserts
        if (m_arch != Arch::x86_64) {
            Error(SourcePos(), "macOS target supports only x86_64.");
            exit(1);
        }
        triple.setArch(llvm::Triple::ArchType::x86_64);
        triple.setVendor(llvm::Triple::VendorType::Apple);
        triple.setOS(llvm::Triple::OSType::MacOSX);
        break;
    case TargetOS::android:
        if (m_arch == Arch::x86) {
            triple.setArchName("i686");
        } else if (m_arch == Arch::x86_64) {
            triple.setArchName("x86_64");
        } else if (m_arch == Arch::arm) {
            triple.setArchName("armv7");
        } else if (m_arch == Arch::aarch64) {
            triple.setArchName("aarch64");
        } else {
            Error(SourcePos(), "Unknown arch.");
            exit(1);
        }
        triple.setVendor(llvm::Triple::VendorType::UnknownVendor);
        triple.setOS(llvm::Triple::OSType::Linux);
        triple.setEnvironment(llvm::Triple::EnvironmentType::Android);
        break;
    case TargetOS::ios:
        if (m_arch != Arch::aarch64) {
            Error(SourcePos(), "iOS target supports only aarch64.");
            exit(1);
        }
        // Note, for iOS arch need to be set to "arm64", instead of "aarch64".
        // Internet say this is for historical reasons.
        // "arm64-apple-ios"
        triple.setArchName("arm64");
        triple.setVendor(llvm::Triple::VendorType::Apple);
        triple.setOS(llvm::Triple::OSType::IOS);
        break;
    case TargetOS::ps4:
        if (m_arch != Arch::x86_64) {
            Error(SourcePos(), "PS4 target supports only x86_64.");
            exit(1);
        }
        // "x86_64-scei-ps4"
        triple.setArch(llvm::Triple::ArchType::x86_64);
        triple.setVendor(llvm::Triple::VendorType::SCEI);
        triple.setOS(llvm::Triple::OSType::PS4);
        break;
    case TargetOS::web:
        if (m_arch != Arch::wasm32) {
            Error(SourcePos(), "Web target supports only wasm32.");
            exit(1);
        }
        triple.setArch(llvm::Triple::ArchType::wasm32);
        triple.setVendor(llvm::Triple::VendorType::UnknownVendor);
        triple.setOS(llvm::Triple::OSType::UnknownOS);
        break;
    case TargetOS::error:
        Error(SourcePos(), "Invalid target OS.");
        exit(1);
    }

    return triple.str();
}

// This function returns string representation of ISA for the purpose of
// mangling. And may return any unique string, preferably short, like
// sse4, avx and etc.
const char *Target::ISAToString(ISA isa) {
    switch (isa) {
#ifdef ISPC_ARM_ENABLED
    case Target::NEON:
        return "neon";
#endif
#ifdef ISPC_WASM_ENABLED
    case Target::WASM:
        return "wasm";
#endif
    case Target::SSE2:
        return "sse2";
    case Target::SSE4:
        return "sse4";
    case Target::AVX:
        return "avx";
    case Target::AVX2:
        return "avx2";
    case Target::KNL_AVX512:
        return "avx512knl";
    case Target::SKX_AVX512:
        return "avx512skx";
#ifdef ISPC_GENX_ENABLED
    case Target::GENX:
        return "genx";
#endif
    default:
        FATAL("Unhandled target in ISAToString()");
    }
    return "";
}

const char *Target::GetISAString() const { return ISAToString(m_isa); }

// This function returns string representation of default target corresponding
// to ISA. I.e. for SSE4 it's sse4-i32x4, for AVX2 it's avx2-i32x8. This
// string may be used to initialize Target.
const char *Target::ISAToTargetString(ISA isa) {
    switch (isa) {
#ifdef ISPC_ARM_ENABLED
    case Target::NEON:
        return "neon-i32x4";
#endif
#ifdef ISPC_WASM_ENABLED
    case Target::WASM:
        return "wasm-i32x4";
#endif
#ifdef ISPC_GENX_ENABLED
    case Target::GENX:
        return "genx-x16";
#endif
    case Target::SSE2:
        return "sse2-i32x4";
    case Target::SSE4:
        return "sse4-i32x4";
    case Target::AVX:
        return "avx1-i32x8";
    case Target::AVX2:
        return "avx2-i32x8";
    case Target::KNL_AVX512:
        return "avx512knl-i32x16";
    case Target::SKX_AVX512:
        return "avx512skx-i32x16";
    default:
        FATAL("Unhandled target in ISAToTargetString()");
    }
    return "";
}

const char *Target::GetISATargetString() const { return ISAToTargetString(m_isa); }

llvm::Value *Target::SizeOf(llvm::Type *type, llvm::BasicBlock *insertAtEnd) {
    uint64_t byteSize = getDataLayout()->getTypeStoreSize(type);
    if (m_is32Bit || g->opt.force32BitAddressing)
        return LLVMInt32((int32_t)byteSize);
    else
        return LLVMInt64(byteSize);
}

llvm::Value *Target::StructOffset(llvm::Type *type, int element, llvm::BasicBlock *insertAtEnd) {
    llvm::StructType *structType = llvm::dyn_cast<llvm::StructType>(type);
    if (structType == NULL || structType->isSized() == false) {
        Assert(m->errorCount > 0);
        return NULL;
    }

    const llvm::StructLayout *sl = getDataLayout()->getStructLayout(structType);
    Assert(sl != NULL);

    uint64_t offset = sl->getElementOffset(element);
    if (m_is32Bit || g->opt.force32BitAddressing)
        return LLVMInt32((int32_t)offset);
    else
        return LLVMInt64(offset);
}

void Target::markFuncWithTargetAttr(llvm::Function *func) {
    if (m_tf_attributes) {
        func->addAttributes(llvm::AttributeList::FunctionIndex, *m_tf_attributes);
    }
}

void Target::markFuncWithCallingConv(llvm::Function *func) {
    assert(g->calling_conv != CallingConv::uninitialized);
    if (g->calling_conv == CallingConv::x86_vectorcall) {
        func->setCallingConv(llvm::CallingConv::X86_VectorCall);
        // Add x86 vectorcall changes as a separate commit.
        /*
        // We have to jump through some hoops for x86.
        // In LLVM IR for x86, arguments which are to be passed in registers
        // have to marked with 'InReg' attribue.
        // Rules(Ref : https://docs.microsoft.com/en-us/cpp/cpp/vectorcall?view=vs-2019 )
        // Definitions:
        // Integer Type : it fits in the native register size of the processor�for example,
        // 4 bytes on an x86 machine.Integer types include pointer, reference, and struct or union types of 4 bytes or
        less.
        // Vector Type : either a floating - point type�for example, a float or double�or an SIMD vector type�for
        // example, __m128 or __m256.
        // Rules for x86: Integer Type : The first two integer type arguments found in the
        // parameter list from left to right are placed in ECX and EDX, respectively.
        // Vector Type : The first six vector type arguments in order from left to right are passed by value in SSE
        vector registers 0 to 5.
        //The seventh and subsequent vector type arguments are passed on the stack by reference to memory allocated by
        the caller.
        // Observations from Clang(Is there somewhere these rules are mentioned??)
        // Integer Type : After first Integer Type greater than 32 bit, other integer types NOT passed in reg.
        // Vector Type : After 6 Vector Type args, if 2 Integer Type registers are not yet used, VectorType args
        // passed by reference via register - TO DO

        if (m_arch == Arch::x86) {
            llvm::Function::arg_iterator argIter = func->arg_begin();
            llvm::FunctionType *fType = func->getFunctionType();
            int numArgsVecInReg = 0;
            int numArgsIntInReg = 0;
            for (; argIter != func->arg_end(); ++argIter) {
                llvm::Type *argType = fType->getParamType(argIter->getArgNo());
                if (argType->isIntegerTy() || argType->isStructTy() || argType->isPointerTy()) {
                    if (((argType->isIntegerTy()) || (argType->isStructTy())) &&
                        (g->target->getDataLayout()->getTypeSizeInBits(argType) > 32)) {
                        numArgsIntInReg = 2;
                        continue;
                    }

                    numArgsIntInReg++;
                    argIter->addAttr(llvm::Attribute::InReg);
                    continue;
                }
                if (((llvm::dyn_cast<llvm::VectorType>(argType) != NULL) || argType->isFloatTy() ||
                     argType->isDoubleTy())) {
                    numArgsVecInReg++;
                    argIter->addAttr(llvm::Attribute::InReg);
                }

                if ((numArgsIntInReg == 2) && (numArgsVecInReg == 6))
                    break;
            }
        }*/
    }
}

#ifdef ISPC_GENX_ENABLED
Target::GENX_PLATFORM Target::getGenxPlatform() const {
    AllCPUs a;
    switch (a.GetTypeFromName(m_cpu)) {
    case CPU_GENX:
        return GENX_PLATFORM::GENX_GEN9;
    case CPU_GENX_TGLLP:
        return GENX_PLATFORM::GENX_TGLLP;
    default:
        return GENX_PLATFORM::GENX_GEN9;
    }
    return GENX_PLATFORM::GENX_GEN9;
}

uint32_t Target::getGenxGrfSize() const {
    switch (getGenxPlatform()) {
    case GENX_GEN9:
    case GENX_TGLLP:
        return 32;
    default:
        return 32;
    }
    return 32;
}

bool Target::hasGenxPrefetch() const {
    switch (getGenxPlatform()) {
    case GENX_GEN9:
    case GENX_TGLLP:
        return false;
    default:
        return true;
    }
    return true;
}
#endif

///////////////////////////////////////////////////////////////////////////
// Opt

Opt::Opt() {
    level = 1;
    fastMath = false;
    fastMaskedVload = false;
    force32BitAddressing = true;
    unrollLoops = true;
    disableAsserts = false;
    disableFMA = false;
    forceAlignedMemory = false;
    disableMaskAllOnOptimizations = false;
    disableHandlePseudoMemoryOps = false;
    disableBlendedMaskedStores = false;
    disableCoherentControlFlow = false;
    disableUniformControlFlow = false;
    disableGatherScatterOptimizations = false;
    disableMaskedStoreToStore = false;
    disableGatherScatterFlattening = false;
    disableUniformMemoryOptimizations = false;
    disableCoalescing = false;
    disableZMM = false;
#ifdef ISPC_GENX_ENABLED
    disableGenXGatherCoalescing = false;
    enableForeachInsideVarying = false;
    emitGenXHardwareMask = false;
#endif
}

///////////////////////////////////////////////////////////////////////////
// Globals

Globals::Globals() {
    target_registry = TargetLibRegistry::getTargetLibRegistry();

    mathLib = Globals::Math_ISPC;
    codegenOptLevel = Globals::Aggressive;

    includeStdlib = true;
    runCPP = true;
    debugPrint = false;
    dumpFile = false;
    printTarget = false;
    NoOmitFramePointer = false;
    debugIR = -1;
    disableWarnings = false;
    warningsAsErrors = false;
    quiet = false;
    forceColoredOutput = false;
    disableLineWrap = false;
    emitPerfWarnings = true;
    emitInstrumentation = false;
    noPragmaOnce = false;
    generateDebuggingSymbols = false;
    generateDWARFVersion = 3;
    enableFuzzTest = false;
    fuzzTestSeed = -1;
    mangleFunctionsWithTarget = false;
    isMultiTargetCompilation = false;
    errorLimit = -1;

#if ISPC_LLVM_VERSION >= ISPC_LLVM_10_0
    enableTimeTrace = false;
    // set default granularity to 500.
    timeTraceGranularity = 500;
#endif
    target = NULL;
    ctx = new llvm::LLVMContext;

#ifdef ISPC_HOST_IS_WINDOWS
    _getcwd(currentDirectory, sizeof(currentDirectory));
#else
    if (getcwd(currentDirectory, sizeof(currentDirectory)) == NULL)
        FATAL("Current directory path is too long!");
#endif
    forceAlignment = -1;
    dllExport = false;

    // Target OS defaults to host OS.
    target_os = GetHostOS();

    // Set calling convention to 'uninitialized'.
    // This needs to be set once target OS is decided.
    calling_conv = CallingConv::uninitialized;
}

///////////////////////////////////////////////////////////////////////////
// SourcePos

SourcePos::SourcePos(const char *n, int fl, int fc, int ll, int lc) {
    name = n;
    if (name == NULL) {
        if (m != NULL)
            name = m->module->getModuleIdentifier().c_str();
        else
            name = "(unknown)";
    }
    first_line = fl;
    first_column = fc;
    last_line = ll != 0 ? ll : fl;
    last_column = lc != 0 ? lc : fc;
}

llvm::DIFile *
// llvm::MDFile*
SourcePos::GetDIFile() const {
    std::string directory, filename;
    GetDirectoryAndFileName(g->currentDirectory, name, &directory, &filename);
    llvm::DIFile *ret = m->diBuilder->createFile(filename, directory);
    return ret;
}

llvm::DINamespace *SourcePos::GetDINamespace() const {
    llvm::DIScope *discope = GetDIFile();
    llvm::DINamespace *ret = m->diBuilder->createNameSpace(discope, "ispc", true);
    return ret;
}

void SourcePos::Print() const {
    printf(" @ [%s:%d.%d - %d.%d] ", name, first_line, first_column, last_line, last_column);
}

bool SourcePos::operator==(const SourcePos &p2) const {
    return (!strcmp(name, p2.name) && first_line == p2.first_line && first_column == p2.first_column &&
            last_line == p2.last_line && last_column == p2.last_column);
}

SourcePos Union(const SourcePos &p1, const SourcePos &p2) {
    if (strcmp(p1.name, p2.name) != 0)
        return p1;

    SourcePos ret;
    ret.name = p1.name;
    ret.first_line = std::min(p1.first_line, p2.first_line);
    ret.first_column = std::min(p1.first_column, p2.first_column);
    ret.last_line = std::max(p1.last_line, p2.last_line);
    ret.last_column = std::max(p1.last_column, p2.last_column);
    return ret;
}