/*========================== begin_copyright_notice ============================

Copyright (C) 2017-2021 Intel Corporation

SPDX-License-Identifier: MIT

============================= end_copyright_notice ===========================*/

/*========================== begin_copyright_notice ============================

This file is distributed under the University of Illinois Open Source License.
See LICENSE.TXT for details.

============================= end_copyright_notice ===========================*/

/*========================== begin_copyright_notice ============================

Copyright (C) 2014 Advanced Micro Devices, Inc. All rights reserved.

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal with the Software without restriction, including without limitation
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Software is furnished to do so, subject to the following conditions:

Redistributions of source code must retain the above copyright notice,
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Neither the names of Advanced Micro Devices, Inc., nor the names of its
contributors may be used to endorse or promote products derived from this
Software without specific prior written permission.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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============================= end_copyright_notice ===========================*/

// This file defines utility classes and functions shared by SPIR-V
// reader/writer.

#include "common/LLVMWarningsPush.hpp"

#include "llvmWrapper/IR/DerivedTypes.h"
#include "llvmWrapper/Bitcode/BitcodeWriter.h"
#include "llvm/IR/Attributes.h"
#include "llvm/Support/ToolOutputFile.h"

#include <llvm/Support/ScaledNumber.h>
#include "llvm/ADT/StringExtras.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "common/LLVMWarningsPop.hpp"

#include "libSPIRV/SPIRVInstruction.h"
#include "SPIRVInternal.h"
#include "Mangler/ParameterType.h"
#include "Probe/Assertion.h"

namespace igc_spv{

void
saveLLVMModule(Module *M, const std::string &OutputFile) {
  std::error_code EC;
  llvm::ToolOutputFile Out(OutputFile.c_str(), EC, sys::fs::F_None);
  IGC_ASSERT_EXIT_MESSAGE((!EC), "Failed to open file");
  IGCLLVM::WriteBitcodeToFile(M, Out.os());
  Out.keep();
}

PointerType*
getOrCreateOpaquePtrType(Module *M, const std::string &Name,
    unsigned AddrSpace) {
  auto OpaqueType = M->getTypeByName(Name);
  if (!OpaqueType)
    OpaqueType = StructType::create(M->getContext(), Name);
  return PointerType::get(OpaqueType, AddrSpace);
}

void
getFunctionTypeParameterTypes(llvm::FunctionType* FT,
    std::vector<Type*>& ArgTys) {
  for (auto I = FT->param_begin(), E = FT->param_end(); I != E; ++I) {
    ArgTys.push_back(*I);
  }
}

Function *
getOrCreateFunction(Module *M, Type *RetTy, ArrayRef<Type *> ArgTypes,
    StringRef Name, bool builtin, AttributeList *Attrs, bool takeName) {
  std::string FuncName(Name);
  if (builtin)
     decorateSPIRVBuiltin(FuncName, ArgTypes);

  FunctionType *FT = FunctionType::get(
      RetTy,
      ArgTypes,
      false);
  Function *F = M->getFunction(FuncName);
  if (!F || F->getFunctionType() != FT) {
    auto NewF = Function::Create(FT,
      GlobalValue::ExternalLinkage,
      FuncName,
      M);
    if (F && takeName)
      NewF->takeName(F);
    F = NewF;
    F->setCallingConv(CallingConv::SPIR_FUNC);
    if (Attrs)
      F->setAttributes(*Attrs);
  }
  return F;
}

std::vector<Value *>
getArguments(CallInst* CI) {
  std::vector<Value*> Args;
  for (unsigned I = 0, E = CI->getNumArgOperands(); I != E; ++I) {
    Args.push_back(CI->getArgOperand(I));
  }
  return Args;
}

std::string recursive_mangle(const Type* pType)
{
    Type::TypeID ID = pType->getTypeID();

    switch (ID)
    {
        case Type::FloatTyID:
            return "f32";
        case Type::DoubleTyID:
            return "f64";
        case Type::HalfTyID:
            return "f16";
        case Type::IntegerTyID:
            return "i" + utostr(pType->getIntegerBitWidth());
        case IGCLLVM::VectorTyID:
        {
            unsigned vecLen = (unsigned)cast<VectorType>(pType)->getNumElements();
            Type* pEltType = cast<VectorType>(pType)->getElementType();
            return "v" + utostr(vecLen) + recursive_mangle(pEltType);
        }
        case Type::PointerTyID:
        {
            unsigned int AS = pType->getPointerAddressSpace();
            Type* pPointeeType = pType->getPointerElementType();

            if (isa<StructType>(pPointeeType) && cast<StructType>(pPointeeType)->isOpaque())
            {
                return "i64";
            }

            return "p" + utostr(AS) + recursive_mangle(pPointeeType);
        }
        case Type::StructTyID:
        {
            auto structName = cast<StructType>(pType)->getName().str();
            auto pointPos = structName.rfind('.');
            return pointPos != structName.npos ? structName.substr(pointPos + 1) : structName;
        }
        case Type::FunctionTyID:
        {
            return "func";
        }
        case Type::ArrayTyID:
        {
            auto elemType = pType->getArrayElementType();
            auto numElems = pType->getArrayNumElements();
            return "a" + utostr(numElems) + recursive_mangle(elemType);
        }
        default:
            IGC_ASSERT_EXIT_MESSAGE(0, "unhandled type to mangle!");
            return "";
    }
}


std::string Mangler(const std::string &FuncName, const std::vector<Type*> &ArgTypes)
{
    std::string str_type;
    for (auto U : ArgTypes)
    {
        str_type += "_" + recursive_mangle(U);
    }
    return FuncName + str_type;
}

void
decorateSPIRVBuiltin(std::string &S)
{
    S = std::string(kLLVMName::builtinPrefix) + S;
}

void
decorateSPIRVBuiltin(std::string &S, std::vector<Type*> ArgTypes) {
   S.assign(std::string(kLLVMName::builtinPrefix) + Mangler(S,ArgTypes));
}

void
decorateSPIRVExtInst(std::string &S, std::vector<Type*> ArgTypes) {
   S.assign(std::string(kLLVMName::builtinExtInstPrefixOpenCL) + Mangler(S,ArgTypes));
}

bool
isFunctionBuiltin(llvm::Function* F) {
  return F && F->isDeclaration() && F->getName().startswith(kLLVMName::builtinPrefix);
}

std::string
getSPIRVBuiltinName(Op OC, SPIRVInstruction *BI, std::vector<Type*> ArgTypes, std::string suffix) {
  std::string name = "";
  bool hasI32Postfix = false;

  if (isIntelSubgroupOpCode(OC)) {
    std::stringstream tmpName;
    SPIRVType *DataTy = nullptr;
    switch (OC) {
    case OpSubgroupBlockReadINTEL:
    case OpSubgroupImageBlockReadINTEL:
      tmpName << "intel_sub_group_block_read";
      DataTy = BI->getType();
      break;
    case OpSubgroupBlockWriteINTEL:
      tmpName << "intel_sub_group_block_write";
      DataTy = BI->getOperands()[1]->getType();
      break;
    case OpSubgroupImageBlockWriteINTEL:
      tmpName << "intel_sub_group_block_write";
      DataTy = BI->getOperands()[2]->getType();
      break;
    case OpSubgroupImageMediaBlockReadINTEL:
      tmpName << OCLSPIRVBuiltinMap::map(OC);
      DataTy = BI->getType();
      hasI32Postfix = true;
      break;
    case OpSubgroupImageMediaBlockWriteINTEL:
      tmpName << OCLSPIRVBuiltinMap::map(OC);
      DataTy = (*BI->getOperands().rbegin())->getType();
      hasI32Postfix = true;
      break;
    default:
      tmpName << OCLSPIRVBuiltinMap::map(OC);
    }
    if (DataTy) {
      if (DataTy->getBitWidth() == 8) {
        tmpName << "_uc";
      }
      else if (DataTy->getBitWidth() == 16) {
        tmpName << "_us";
      }
      else if (DataTy->getBitWidth() == 32 && hasI32Postfix) {
        tmpName << "_ui";
      }
      else if (DataTy->getBitWidth() == 64) {
        tmpName << "_ul";
      }

      if (DataTy->isTypeVector()) {
        if (unsigned ComponentCount = DataTy->getVectorComponentCount())
          tmpName << ComponentCount;
      }
    }
    name = tmpName.str();
  }
  else
  {
    name = OCLSPIRVBuiltinMap::map(OC);
  }

  if (!name.empty()) {
    name = name + suffix;
    decorateSPIRVBuiltin(name, ArgTypes);
  }
  else
  {
    IGC_ASSERT_EXIT_MESSAGE(0, "Couldn't find opcode in map!");
  }
  return name;
}

CallInst *
mutateCallInst(Module *M, CallInst *CI,
    std::function<std::string (CallInst *, std::vector<Value *> &)>ArgMutate,
    bool Mangle, AttributeList *Attrs, bool TakeFuncName) {

  auto Args = getArguments(CI);
  auto NewName = ArgMutate(CI, Args);
  std::string InstName;
  if (!CI->getType()->isVoidTy() && CI->hasName()) {
    InstName = CI->getName().str();
    CI->setName(InstName + ".old");
  }

  auto NewCI = addCallInst(M, NewName, CI->getType(), Args, Attrs, CI, Mangle,
    InstName, TakeFuncName);

  Function* OldF = CI->getCalledFunction();
  Function* NewF = NewCI->getCalledFunction();
  if (!OldF->isDeclaration() &&
    NewF->isDeclaration()) {
    // This means that we need to clone the old function into new one.
    // It is needed because when Clang is compiling to llvm-bc it does the same thing.
    // If we want to link with such modules, we need to make the behaviour similar.
    IGC_ASSERT(OldF->getNumOperands() == NewF->getNumOperands());
    ValueToValueMapTy VMap;
    llvm::SmallVector<llvm::ReturnInst*, 8> Returns;
    BasicBlock* EntryBB = BasicBlock::Create(M->getContext(), "", NewF);
    IRBuilder<> builder(EntryBB);

    for (auto OldArgIt = OldF->arg_begin(), NewArgIt = NewF->arg_begin(); OldArgIt != OldF->arg_end(); ++OldArgIt, ++NewArgIt) {
      NewArgIt->setName(OldArgIt->getName().str());
      if (OldArgIt->getType() == NewArgIt->getType()) {
        VMap[&*OldArgIt] = &*NewArgIt;
      }
      else {
        IGC_ASSERT(NewArgIt->getType()->isPointerTy());
        LoadInst* Load = builder.CreateLoad(&*NewArgIt);
        VMap[&*OldArgIt] = Load;
      }
    }

    CloneFunctionInto(NewF, OldF, VMap, true, Returns);

    // Merge the basic block with Load instruction with the original entry basic block.
    BasicBlock* ClonedEntryBB = cast<BasicBlock>(VMap[&*OldF->begin()]);
    builder.CreateBr(ClonedEntryBB);
  }

  CI->replaceAllUsesWith(NewCI);
  CI->dropAllReferences();
  CI->removeFromParent();
  return NewCI;
}

void
mutateFunction(Function *F,
    std::function<std::string (CallInst *, std::vector<Value *> &)>ArgMutate,
    bool Mangle, AttributeList *Attrs, bool TakeFuncName) {
  auto M = F->getParent();
  for (auto I = F->user_begin(), E = F->user_end(); I != E;) {
    if (auto CI = dyn_cast<CallInst>(*I++))
      mutateCallInst(M, CI, ArgMutate, Mangle, Attrs, TakeFuncName);
  }
  if (F->use_empty()) {
    F->dropAllReferences();
    F->removeFromParent();
  }
}

CallInst *
addCallInst(Module *M, StringRef FuncName, Type *RetTy, ArrayRef<Value *> Args,
    AttributeList *Attrs, Instruction *Pos, bool Mangle, StringRef InstName,
    bool TakeFuncName) {
  auto F = getOrCreateFunction(M, RetTy, getTypes(Args),
      FuncName, Mangle, Attrs, TakeFuncName);
  auto CI = CallInst::Create(F, Args, InstName, Pos);
  CI->setCallingConv(F->getCallingConv());
  return CI;
}

ConstantInt *
getInt64(Module *M, int64_t value) {
  return ConstantInt::get(Type::getInt64Ty(M->getContext()), value, true);
}

ConstantInt *
getInt32(Module *M, int value) {
  return ConstantInt::get(Type::getInt32Ty(M->getContext()), value, true);
}

std::tuple<unsigned short, unsigned char, unsigned char>
decodeOCLVer(unsigned Ver) {
  unsigned short Major = Ver / 100000;
  unsigned char Minor = (Ver % 100000) / 1000;
  unsigned char Rev = Ver % 1000;
  return std::make_tuple(Major, Minor, Rev);
}

}

