//===--- RISCV.cpp - Implement RISC-V target feature support --------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements RISC-V TargetInfo objects.
//
//===----------------------------------------------------------------------===//

#include "RISCV.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/MacroBuilder.h"
#include "clang/Basic/TargetBuiltins.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TargetParser/RISCVTargetParser.h"
#include <optional>

using namespace clang;
using namespace clang::targets;

ArrayRef<const char *> RISCVTargetInfo::getGCCRegNames() const {
  static const char *const GCCRegNames[] = {
      // Integer registers
      "x0",  "x1",  "x2",  "x3",  "x4",  "x5",  "x6",  "x7",
      "x8",  "x9",  "x10", "x11", "x12", "x13", "x14", "x15",
      "x16", "x17", "x18", "x19", "x20", "x21", "x22", "x23",
      "x24", "x25", "x26", "x27", "x28", "x29", "x30", "x31",

      // Floating point registers
      "f0",  "f1",  "f2",  "f3",  "f4",  "f5",  "f6",  "f7",
      "f8",  "f9",  "f10", "f11", "f12", "f13", "f14", "f15",
      "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
      "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31",

      // Vector registers
      "v0",  "v1",  "v2",  "v3",  "v4",  "v5",  "v6",  "v7",
      "v8",  "v9",  "v10", "v11", "v12", "v13", "v14", "v15",
      "v16", "v17", "v18", "v19", "v20", "v21", "v22", "v23",
      "v24", "v25", "v26", "v27", "v28", "v29", "v30", "v31"};
  return llvm::ArrayRef(GCCRegNames);
}

ArrayRef<TargetInfo::GCCRegAlias> RISCVTargetInfo::getGCCRegAliases() const {
  static const TargetInfo::GCCRegAlias GCCRegAliases[] = {
      {{"zero"}, "x0"}, {{"ra"}, "x1"},   {{"sp"}, "x2"},    {{"gp"}, "x3"},
      {{"tp"}, "x4"},   {{"t0"}, "x5"},   {{"t1"}, "x6"},    {{"t2"}, "x7"},
      {{"s0"}, "x8"},   {{"s1"}, "x9"},   {{"a0"}, "x10"},   {{"a1"}, "x11"},
      {{"a2"}, "x12"},  {{"a3"}, "x13"},  {{"a4"}, "x14"},   {{"a5"}, "x15"},
      {{"a6"}, "x16"},  {{"a7"}, "x17"},  {{"s2"}, "x18"},   {{"s3"}, "x19"},
      {{"s4"}, "x20"},  {{"s5"}, "x21"},  {{"s6"}, "x22"},   {{"s7"}, "x23"},
      {{"s8"}, "x24"},  {{"s9"}, "x25"},  {{"s10"}, "x26"},  {{"s11"}, "x27"},
      {{"t3"}, "x28"},  {{"t4"}, "x29"},  {{"t5"}, "x30"},   {{"t6"}, "x31"},
      {{"ft0"}, "f0"},  {{"ft1"}, "f1"},  {{"ft2"}, "f2"},   {{"ft3"}, "f3"},
      {{"ft4"}, "f4"},  {{"ft5"}, "f5"},  {{"ft6"}, "f6"},   {{"ft7"}, "f7"},
      {{"fs0"}, "f8"},  {{"fs1"}, "f9"},  {{"fa0"}, "f10"},  {{"fa1"}, "f11"},
      {{"fa2"}, "f12"}, {{"fa3"}, "f13"}, {{"fa4"}, "f14"},  {{"fa5"}, "f15"},
      {{"fa6"}, "f16"}, {{"fa7"}, "f17"}, {{"fs2"}, "f18"},  {{"fs3"}, "f19"},
      {{"fs4"}, "f20"}, {{"fs5"}, "f21"}, {{"fs6"}, "f22"},  {{"fs7"}, "f23"},
      {{"fs8"}, "f24"}, {{"fs9"}, "f25"}, {{"fs10"}, "f26"}, {{"fs11"}, "f27"},
      {{"ft8"}, "f28"}, {{"ft9"}, "f29"}, {{"ft10"}, "f30"}, {{"ft11"}, "f31"}};
  return llvm::ArrayRef(GCCRegAliases);
}

bool RISCVTargetInfo::validateAsmConstraint(
    const char *&Name, TargetInfo::ConstraintInfo &Info) const {
  switch (*Name) {
  default:
    return false;
  case 'I':
    // A 12-bit signed immediate.
    Info.setRequiresImmediate(-2048, 2047);
    return true;
  case 'J':
    // Integer zero.
    Info.setRequiresImmediate(0);
    return true;
  case 'K':
    // A 5-bit unsigned immediate for CSR access instructions.
    Info.setRequiresImmediate(0, 31);
    return true;
  case 'f':
    // A floating-point register.
    Info.setAllowsRegister();
    return true;
  case 'A':
    // An address that is held in a general-purpose register.
    Info.setAllowsMemory();
    return true;
  case 'S': // A symbolic address
    Info.setAllowsRegister();
    return true;
  case 'v':
    // A vector register.
    if (Name[1] == 'r' || Name[1] == 'm') {
      Info.setAllowsRegister();
      Name += 1;
      return true;
    }
    return false;
  }
}

std::string RISCVTargetInfo::convertConstraint(const char *&Constraint) const {
  std::string R;
  switch (*Constraint) {
  case 'v':
    R = std::string("^") + std::string(Constraint, 2);
    Constraint += 1;
    break;
  default:
    R = TargetInfo::convertConstraint(Constraint);
    break;
  }
  return R;
}

static unsigned getVersionValue(unsigned MajorVersion, unsigned MinorVersion) {
  return MajorVersion * 1000000 + MinorVersion * 1000;
}

void RISCVTargetInfo::getTargetDefines(const LangOptions &Opts,
                                       MacroBuilder &Builder) const {
  Builder.defineMacro("__riscv");
  bool Is64Bit = getTriple().getArch() == llvm::Triple::riscv64;
  Builder.defineMacro("__riscv_xlen", Is64Bit ? "64" : "32");
  StringRef CodeModel = getTargetOpts().CodeModel;
  unsigned FLen = ISAInfo->getFLen();
  unsigned MinVLen = ISAInfo->getMinVLen();
  unsigned MaxELen = ISAInfo->getMaxELen();
  unsigned MaxELenFp = ISAInfo->getMaxELenFp();
  if (CodeModel == "default")
    CodeModel = "small";

  if (CodeModel == "small")
    Builder.defineMacro("__riscv_cmodel_medlow");
  else if (CodeModel == "medium")
    Builder.defineMacro("__riscv_cmodel_medany");

  StringRef ABIName = getABI();
  if (ABIName == "ilp32f" || ABIName == "lp64f")
    Builder.defineMacro("__riscv_float_abi_single");
  else if (ABIName == "ilp32d" || ABIName == "lp64d")
    Builder.defineMacro("__riscv_float_abi_double");
  else
    Builder.defineMacro("__riscv_float_abi_soft");

  if (ABIName == "ilp32e")
    Builder.defineMacro("__riscv_abi_rve");

  Builder.defineMacro("__riscv_arch_test");

  for (auto &Extension : ISAInfo->getExtensions()) {
    auto ExtName = Extension.first;
    auto ExtInfo = Extension.second;

    Builder.defineMacro(
        Twine("__riscv_", ExtName),
        Twine(getVersionValue(ExtInfo.MajorVersion, ExtInfo.MinorVersion)));
  }

  if (ISAInfo->hasExtension("m") || ISAInfo->hasExtension("zmmul"))
    Builder.defineMacro("__riscv_mul");

  if (ISAInfo->hasExtension("m")) {
    Builder.defineMacro("__riscv_div");
    Builder.defineMacro("__riscv_muldiv");
  }

  if (ISAInfo->hasExtension("a")) {
    Builder.defineMacro("__riscv_atomic");
    Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_1");
    Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2");
    Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4");
    if (Is64Bit)
      Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8");
  }

  if (FLen) {
    Builder.defineMacro("__riscv_flen", Twine(FLen));
    Builder.defineMacro("__riscv_fdiv");
    Builder.defineMacro("__riscv_fsqrt");
  }

  if (MinVLen) {
    Builder.defineMacro("__riscv_v_min_vlen", Twine(MinVLen));
    Builder.defineMacro("__riscv_v_elen", Twine(MaxELen));
    Builder.defineMacro("__riscv_v_elen_fp", Twine(MaxELenFp));
  }

  if (ISAInfo->hasExtension("c"))
    Builder.defineMacro("__riscv_compressed");

  if (ISAInfo->hasExtension("zve32x")) {
    Builder.defineMacro("__riscv_vector");
    // Currently we support the v0.12 RISC-V V intrinsics.
    Builder.defineMacro("__riscv_v_intrinsic", Twine(getVersionValue(0, 12)));
  }

  auto VScale = getVScaleRange(Opts);
  if (VScale && VScale->first && VScale->first == VScale->second)
    Builder.defineMacro("__riscv_v_fixed_vlen",
                        Twine(VScale->first * llvm::RISCV::RVVBitsPerBlock));
}

static constexpr Builtin::Info BuiltinInfo[] = {
#define BUILTIN(ID, TYPE, ATTRS)                                               \
  {#ID, TYPE, ATTRS, nullptr, HeaderDesc::NO_HEADER, ALL_LANGUAGES},
#define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE)                               \
  {#ID, TYPE, ATTRS, FEATURE, HeaderDesc::NO_HEADER, ALL_LANGUAGES},
#include "clang/Basic/BuiltinsRISCVVector.def"
#define BUILTIN(ID, TYPE, ATTRS)                                               \
  {#ID, TYPE, ATTRS, nullptr, HeaderDesc::NO_HEADER, ALL_LANGUAGES},
#define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE)                               \
  {#ID, TYPE, ATTRS, FEATURE, HeaderDesc::NO_HEADER, ALL_LANGUAGES},
#include "clang/Basic/BuiltinsRISCV.def"
};

ArrayRef<Builtin::Info> RISCVTargetInfo::getTargetBuiltins() const {
  return llvm::ArrayRef(BuiltinInfo,
                        clang::RISCV::LastTSBuiltin - Builtin::FirstTSBuiltin);
}

bool RISCVTargetInfo::initFeatureMap(
    llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags, StringRef CPU,
    const std::vector<std::string> &FeaturesVec) const {

  unsigned XLen = 32;

  if (getTriple().getArch() == llvm::Triple::riscv64) {
    Features["64bit"] = true;
    XLen = 64;
  } else {
    Features["32bit"] = true;
  }

  auto ParseResult = llvm::RISCVISAInfo::parseFeatures(XLen, FeaturesVec);
  if (!ParseResult) {
    std::string Buffer;
    llvm::raw_string_ostream OutputErrMsg(Buffer);
    handleAllErrors(ParseResult.takeError(), [&](llvm::StringError &ErrMsg) {
      OutputErrMsg << ErrMsg.getMessage();
    });
    Diags.Report(diag::err_invalid_feature_combination) << OutputErrMsg.str();
    return false;
  }

  // RISCVISAInfo makes implications for ISA features
  std::vector<std::string> ImpliedFeatures = (*ParseResult)->toFeatureVector();
  // Add non-ISA features like `relax` and `save-restore` back
  for (const std::string &Feature : FeaturesVec)
    if (!llvm::is_contained(ImpliedFeatures, Feature))
      ImpliedFeatures.push_back(Feature);

  return TargetInfo::initFeatureMap(Features, Diags, CPU, ImpliedFeatures);
}

std::optional<std::pair<unsigned, unsigned>>
RISCVTargetInfo::getVScaleRange(const LangOptions &LangOpts) const {
  // RISCV::RVVBitsPerBlock is 64.
  unsigned VScaleMin = ISAInfo->getMinVLen() / llvm::RISCV::RVVBitsPerBlock;

  if (LangOpts.VScaleMin || LangOpts.VScaleMax) {
    // Treat Zvl*b as a lower bound on vscale.
    VScaleMin = std::max(VScaleMin, LangOpts.VScaleMin);
    unsigned VScaleMax = LangOpts.VScaleMax;
    if (VScaleMax != 0 && VScaleMax < VScaleMin)
      VScaleMax = VScaleMin;
    return std::pair<unsigned, unsigned>(VScaleMin ? VScaleMin : 1, VScaleMax);
  }

  if (VScaleMin > 0) {
    unsigned VScaleMax = ISAInfo->getMaxVLen() / llvm::RISCV::RVVBitsPerBlock;
    return std::make_pair(VScaleMin, VScaleMax);
  }

  return std::nullopt;
}

/// Return true if has this feature, need to sync with handleTargetFeatures.
bool RISCVTargetInfo::hasFeature(StringRef Feature) const {
  bool Is64Bit = getTriple().getArch() == llvm::Triple::riscv64;
  auto Result = llvm::StringSwitch<std::optional<bool>>(Feature)
                    .Case("riscv", true)
                    .Case("riscv32", !Is64Bit)
                    .Case("riscv64", Is64Bit)
                    .Case("32bit", !Is64Bit)
                    .Case("64bit", Is64Bit)
                    .Default(std::nullopt);
  if (Result)
    return *Result;

  if (ISAInfo->isSupportedExtensionFeature(Feature))
    return ISAInfo->hasExtension(Feature);

  return false;
}

/// Perform initialization based on the user configured set of features.
bool RISCVTargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
                                           DiagnosticsEngine &Diags) {
  unsigned XLen = getTriple().isArch64Bit() ? 64 : 32;
  auto ParseResult = llvm::RISCVISAInfo::parseFeatures(XLen, Features);
  if (!ParseResult) {
    std::string Buffer;
    llvm::raw_string_ostream OutputErrMsg(Buffer);
    handleAllErrors(ParseResult.takeError(), [&](llvm::StringError &ErrMsg) {
      OutputErrMsg << ErrMsg.getMessage();
    });
    Diags.Report(diag::err_invalid_feature_combination) << OutputErrMsg.str();
    return false;
  } else {
    ISAInfo = std::move(*ParseResult);
  }

  if (ABI.empty())
    ABI = ISAInfo->computeDefaultABI().str();

  if (ISAInfo->hasExtension("zfh") || ISAInfo->hasExtension("zhinx"))
    HasLegalHalfType = true;

  return true;
}

bool RISCVTargetInfo::isValidCPUName(StringRef Name) const {
  bool Is64Bit = getTriple().isArch64Bit();
  return llvm::RISCV::parseCPU(Name, Is64Bit);
}

void RISCVTargetInfo::fillValidCPUList(
    SmallVectorImpl<StringRef> &Values) const {
  bool Is64Bit = getTriple().isArch64Bit();
  llvm::RISCV::fillValidCPUArchList(Values, Is64Bit);
}

bool RISCVTargetInfo::isValidTuneCPUName(StringRef Name) const {
  bool Is64Bit = getTriple().isArch64Bit();
  return llvm::RISCV::parseTuneCPU(Name, Is64Bit);
}

void RISCVTargetInfo::fillValidTuneCPUList(
    SmallVectorImpl<StringRef> &Values) const {
  bool Is64Bit = getTriple().isArch64Bit();
  llvm::RISCV::fillValidTuneCPUArchList(Values, Is64Bit);
}