//===- DXILMetadata.cpp - DXIL Metadata helper objects --------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file This file contains helper objects for working with DXIL metadata.
///
//===----------------------------------------------------------------------===//

#include "DXILMetadata.h"
#include "llvm/ADT/Triple.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/VersionTuple.h"

using namespace llvm;
using namespace llvm::dxil;

ValidatorVersionMD::ValidatorVersionMD(Module &M)
    : Entry(M.getOrInsertNamedMetadata("dx.valver")) {}

void ValidatorVersionMD::update(VersionTuple ValidatorVer) {
  auto &Ctx = Entry->getParent()->getContext();
  IRBuilder<> B(Ctx);
  Metadata *MDVals[2];

  MDVals[0] = ConstantAsMetadata::get(B.getInt32(ValidatorVer.getMajor()));
  MDVals[1] =
      ConstantAsMetadata::get(B.getInt32(ValidatorVer.getMinor().value_or(0)));

  if (isEmpty())
    Entry->addOperand(MDNode::get(Ctx, MDVals));
  else
    Entry->setOperand(0, MDNode::get(Ctx, MDVals));
}

bool ValidatorVersionMD::isEmpty() { return Entry->getNumOperands() == 0; }

static StringRef getShortShaderStage(Triple::EnvironmentType Env) {
  switch (Env) {
  case Triple::Pixel:
    return "ps";
  case Triple::Vertex:
    return "vs";
  case Triple::Geometry:
    return "gs";
  case Triple::Hull:
    return "hs";
  case Triple::Domain:
    return "ds";
  case Triple::Compute:
    return "cs";
  case Triple::Library:
    return "lib";
  case Triple::Mesh:
    return "ms";
  case Triple::Amplification:
    return "as";
  default:
    break;
  }
  llvm_unreachable("Unsupported environment for DXIL generation.");
  return "";
}

void dxil::createShaderModelMD(Module &M) {
  NamedMDNode *Entry = M.getOrInsertNamedMetadata("dx.shaderModel");
  Triple TT(M.getTargetTriple());
  VersionTuple Ver = TT.getOSVersion();
  LLVMContext &Ctx = M.getContext();
  IRBuilder<> B(Ctx);

  Metadata *Vals[3];
  Vals[0] = MDString::get(Ctx, getShortShaderStage(TT.getEnvironment()));
  Vals[1] = ConstantAsMetadata::get(B.getInt32(Ver.getMajor()));
  Vals[2] = ConstantAsMetadata::get(B.getInt32(Ver.getMinor().value_or(0)));
  Entry->addOperand(MDNode::get(Ctx, Vals));
}