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

Copyright (c) 2017 Intel Corporation

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
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permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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======================= end_copyright_notice ==================================*/

#include "Compiler/Optimizer/OpenCLPasses/ExtenstionFuncs/ExtensionFuncResolution.hpp"
#include "Compiler/Optimizer/OpenCLPasses/ExtenstionFuncs/ExtensionFuncsAnalysis.hpp"
#include "Compiler/IGCPassSupport.h"

#include "common/LLVMWarningsPush.hpp"
#include <llvm/IR/Function.h>
#include <llvm/IR/Instructions.h>
#include "common/LLVMWarningsPop.hpp"

using namespace llvm;
using namespace IGC;

// Register pass to igc-opt
#define PASS_FLAG "igc-extension-funcs-resolution"
#define PASS_DESCRIPTION "Resolves extension function"
#define PASS_CFG_ONLY false
#define PASS_ANALYSIS false
IGC_INITIALIZE_PASS_BEGIN(ExtensionFuncsResolution, PASS_FLAG, PASS_DESCRIPTION, PASS_CFG_ONLY, PASS_ANALYSIS)
IGC_INITIALIZE_PASS_DEPENDENCY(MetaDataUtilsWrapper)
IGC_INITIALIZE_PASS_END(ExtensionFuncsResolution, PASS_FLAG, PASS_DESCRIPTION, PASS_CFG_ONLY, PASS_ANALYSIS)

char ExtensionFuncsResolution::ID = 0;

ExtensionFuncsResolution::ExtensionFuncsResolution() : FunctionPass(ID), m_implicitArgs()
{
    initializeExtensionFuncsResolutionPass(*PassRegistry::getPassRegistry());
}

bool ExtensionFuncsResolution::runOnFunction(Function &F)
{
    m_changed = false;
    m_implicitArgs = ImplicitArgs(F, getAnalysis<MetaDataUtilsWrapper>().getMetaDataUtils());
    visit(F);
    return m_changed;
}

void ExtensionFuncsResolution::visitCallInst(CallInst &CI)
{
    if (!CI.getCalledFunction())
    {
        return;
    }

    StringRef funcName = CI.getCalledFunction()->getName();
    Function& F = *(CI.getParent()->getParent());
    
    ImplicitArg::ArgType argType;
    if( funcName.equals(ExtensionFuncsAnalysis::VME_MB_BLOCK_TYPE) )
    {
        argType = ImplicitArg::VME_MB_BLOCK_TYPE;
    }
    else if( funcName.equals(ExtensionFuncsAnalysis::VME_SUBPIXEL_MODE) )
    {
        argType = ImplicitArg::VME_SUBPIXEL_MODE;
    }
    else if( funcName.equals(ExtensionFuncsAnalysis::VME_SAD_ADJUST_MODE) )
    {
        argType = ImplicitArg::VME_SAD_ADJUST_MODE;
    }
    else if( funcName.equals(ExtensionFuncsAnalysis::VME_SEARCH_PATH_TYPE) )
    {
        argType = ImplicitArg::VME_SEARCH_PATH_TYPE;
    } 
    else {
        // Non VME function, do nothing
        return;
    }

    Value* vmeRes = m_implicitArgs.getArgInFunc(F, argType);

    // Replace original VME call instruction with the appropriate argument, example:

    // Recieves:
    // call i32 @__builtin_IB_vme_subpixel_mode()

    // Creates:
    // %vmeSubpixelMode

    CI.replaceAllUsesWith(vmeRes);
    CI.eraseFromParent();

    m_changed = true;
}
