//===--- LoongArch.cpp - LoongArch Helpers for Tools ------------*- C++ -*-===//

//

// 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

//

//===----------------------------------------------------------------------===//

#include "LoongArch.h"

#include "ToolChains/CommonArgs.h"

#include "clang/Basic/DiagnosticDriver.h"

#include "clang/Driver/Driver.h"

#include "clang/Driver/DriverDiagnostic.h"

#include "clang/Driver/Options.h"

#include "llvm/TargetParser/Host.h"

#include "llvm/TargetParser/LoongArchTargetParser.h"

using namespace clang::driver;

using namespace clang::driver::tools;

using namespace clang;

using namespace llvm::opt;

StringRef loongarch::getLoongArchABI(const Driver &D, const ArgList &Args,

                                     const llvm::Triple &Triple) {

  assert((Triple.getArch() == llvm::Triple::loongarch32 ||

          Triple.getArch() == llvm::Triple::loongarch64) &&

         "Unexpected triple");

  bool IsLA32 = Triple.getArch() == llvm::Triple::loongarch32;

  // Record -mabi value for later use.

  const Arg *MABIArg = Args.getLastArg(options::OPT_mabi_EQ);

  StringRef MABIValue;

  if (MABIArg) {

    MABIValue = MABIArg->getValue();

  }

  // Parse -mfpu value for later use.

  const Arg *MFPUArg = Args.getLastArg(options::OPT_mfpu_EQ);

  int FPU = -1;

  if (MFPUArg) {

    StringRef V = MFPUArg->getValue();

    if (V == "64")

      FPU = 64;

    else if (V == "32")

      FPU = 32;

    else if (V == "0" || 
V == "none"6
)

      FPU = 0;

    else

      D.Diag(diag::err_drv_loongarch_invalid_mfpu_EQ) << V;

  }

  // Check -m*-float firstly since they have highest priority.

  if (const Arg *A = Args.getLastArg(options::OPT_mdouble_float,

                                     options::OPT_msingle_float,

                                     options::OPT_msoft_float)) {

    StringRef ImpliedABI;

    int ImpliedFPU = -1;

    if (A->getOption().matches(options::OPT_mdouble_float)) {

      ImpliedABI = IsLA32 ? 
"ilp32d"1
 : 
"lp64d"6
;

      ImpliedFPU = 64;

    }

    if (A->getOption().matches(options::OPT_msingle_float)) {

      ImpliedABI = IsLA32 ? 
"ilp32f"1
 : 
"lp64f"5
;

      ImpliedFPU = 32;

    }

    if (A->getOption().matches(options::OPT_msoft_float)) {

      ImpliedABI = IsLA32 ? 
"ilp32s"1
 : 
"lp64s"5
;

      ImpliedFPU = 0;

    }

    // Check `-mabi=` and `-mfpu=` settings and report if they conflict with

    // the higher-priority settings implied by -m*-float.

    //

    // ImpliedABI and ImpliedFPU are guaranteed to have valid values because

    // one of the match arms must match if execution can arrive here at all.

    if (!MABIValue.empty() && 
ImpliedABI != MABIValue7
)

      D.Diag(diag::warn_drv_loongarch_conflicting_implied_val)

          << MABIArg->getAsString(Args) << A->getAsString(Args) << ImpliedABI;

    if (FPU != -1 && 
ImpliedFPU != FPU7
)

      D.Diag(diag::warn_drv_loongarch_conflicting_implied_val)

          << MFPUArg->getAsString(Args) << A->getAsString(Args) << ImpliedFPU;

    return ImpliedABI;

  }

  // If `-mabi=` is specified, use it.

  if (!MABIValue.empty())

    return MABIValue;

  // Select abi based on -mfpu=xx.

  switch (FPU) {

  case 64:

    return IsLA32 ? 
"ilp32d"0
 : "lp64d";

  case 32:

    return IsLA32 ? 
"ilp32f"0
 : "lp64f";

  case 0:

    return IsLA32 ? 
"ilp32s"0
 : "lp64s";

  }

  // Choose a default based on the triple.

  // Honor the explicit ABI modifier suffix in triple's environment part if

  // present, falling back to {ILP32,LP64}D otherwise.

  switch (Triple.getEnvironment()) {

  case llvm::Triple::GNUSF:

    return IsLA32 ? 
"ilp32s"1
 : 
"lp64s"3
;

  case llvm::Triple::GNUF32:

    return IsLA32 ? 
"ilp32f"1
 : 
"lp64f"3
;

  case llvm::Triple::GNUF64:

    // This was originally permitted (and indeed the canonical way) to

    // represent the {ILP32,LP64}D ABIs, but in Feb 2023 Loongson decided to

    // drop the explicit suffix in favor of unmarked `-gnu` for the

    // "general-purpose" ABIs, among other non-technical reasons.

    //

    // The spec change did not mention whether existing usages of "gnuf64"

    // shall remain valid or not, so we are going to continue recognizing it

    // for some time, until it is clear that everyone else has migrated away

    // from it.

    [[fallthrough]];

  case llvm::Triple::GNU:

  default:

    return IsLA32 ? 
"ilp32d"13
 : 
"lp64d"78
;

  }

}

void loongarch::getLoongArchTargetFeatures(const Driver &D,

                                           const llvm::Triple &Triple,

                                           const ArgList &Args,

                                           std::vector<StringRef> &Features) {

  std::string ArchName;

  if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))

    ArchName = A->getValue();

  ArchName = postProcessTargetCPUString(ArchName, Triple);

  llvm::LoongArch::getArchFeatures(ArchName, Features);

  // Select floating-point features determined by -mdouble-float,

  // -msingle-float, -msoft-float and -mfpu.

  // Note: -m*-float wins any other options.

  if (const Arg *A = Args.getLastArg(options::OPT_mdouble_float,

                                     options::OPT_msingle_float,

                                     options::OPT_msoft_float)) {

    if (A->getOption().matches(options::OPT_mdouble_float)) {

      Features.push_back("+f");

      Features.push_back("+d");

    } else if (A->getOption().matches(options::OPT_msingle_float)) {

      Features.push_back("+f");

      Features.push_back("-d");

    } else /*Soft-float*/ {

      Features.push_back("-f");

      Features.push_back("-d");

    }

  } else if (const Arg *A = Args.getLastArg(options::OPT_mfpu_EQ)) {

    StringRef FPU = A->getValue();

    if (FPU == "64") {

      Features.push_back("+f");

      Features.push_back("+d");

    } else if (FPU == "32") {

      Features.push_back("+f");

      Features.push_back("-d");

    } else if (FPU == "0" || 
FPU == "none"5
) {

      Features.push_back("-f");

      Features.push_back("-d");

    } else {

      D.Diag(diag::err_drv_loongarch_invalid_mfpu_EQ) << FPU;

    }

  }

  // Select the `ual` feature determined by -m[no-]unaligned-access

  // or the alias -m[no-]strict-align.

  AddTargetFeature(Args, Features, options::OPT_munaligned_access,

                   options::OPT_mno_unaligned_access, "ual");

  // Accept but warn about these TargetSpecific options.

  if (Arg *A = Args.getLastArgNoClaim(options::OPT_mabi_EQ))

    A->ignoreTargetSpecific();

  if (Arg *A = Args.getLastArgNoClaim(options::OPT_mfpu_EQ))

    A->ignoreTargetSpecific();

}

std::string loongarch::postProcessTargetCPUString(const std::string &CPU,

                                                  const llvm::Triple &Triple) {

  std::string CPUString = CPU;

  if (CPUString == "native") {

    CPUString = llvm::sys::getHostCPUName();

    if (CPUString == "generic")

      CPUString = llvm::LoongArch::getDefaultArch(Triple.isLoongArch64());

  }

  if (CPUString.empty())

    CPUString = llvm::LoongArch::getDefaultArch(Triple.isLoongArch64());

  return CPUString;

}

std::string loongarch::getLoongArchTargetCPU(const llvm::opt::ArgList &Args,

                                             const llvm::Triple &Triple) {

  std::string CPU;

  // If we have -march, use that.

  if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))

    CPU = A->getValue();

  return postProcessTargetCPUString(CPU, Triple);

}