llvm-project/llvm/lib/TargetParser/AArch64TargetParser.cpp

//===-- AArch64TargetParser - Parser for AArch64 features -------*- 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
//
//===----------------------------------------------------------------------===//
//
// This file implements a target parser to recognise AArch64 hardware features
// such as FPU/CPU/ARCH and extension names.
//
//===----------------------------------------------------------------------===//

#include "llvm/TargetParser/AArch64TargetParser.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/TargetParser/ARMTargetParserCommon.h"
#include "llvm/TargetParser/Triple.h"
#include <cctype>

using namespace llvm;

static unsigned checkArchVersion(llvm::StringRef Arch) {
  if (Arch.size() >= 2 && Arch[0] == 'v' && std::isdigit(Arch[1]))
    return (Arch[1] - 48);
  return 0;
}

uint64_t AArch64::getDefaultExtensions(StringRef CPU,
                                       const AArch64::ArchInfo &AI) {
  if (CPU == "generic")
    return AI.DefaultExts;

  // Note: this now takes cpu aliases into account
  std::optional<CpuInfo> Cpu = parseCpu(CPU);
  if (!Cpu)
    return AI.DefaultExts;

  return Cpu->Arch.DefaultExts | Cpu->DefaultExtensions;
}

void AArch64::getFeatureOption(StringRef Name, std::string &Feature) {
  for (const auto &E : llvm::AArch64::Extensions) {
    if (Name == E.Name) {
      Feature = E.Feature;
      return;
    }
  }
  Feature = Name.str();
}

std::optional<AArch64::ArchInfo> AArch64::getArchForCpu(StringRef CPU) {
  if (CPU == "generic")
    return ARMV8A;

  // Note: this now takes cpu aliases into account
  std::optional<CpuInfo> Cpu = parseCpu(CPU);
  if (!Cpu)
    return {};
  return Cpu->Arch;
}

std::optional<AArch64::ArchInfo> AArch64::ArchInfo::findBySubArch(StringRef SubArch) {
  for (const auto *A : AArch64::ArchInfos)
    if (A->getSubArch() == SubArch)
      return *A;
  return {};
}

uint64_t AArch64::getCpuSupportsMask(ArrayRef<StringRef> FeatureStrs) {
  uint64_t FeaturesMask = 0;
  for (const StringRef &FeatureStr : FeatureStrs) {
    for (const auto &E : llvm::AArch64::Extensions)
      if (FeatureStr == E.Name) {
        FeaturesMask |= (1ULL << E.CPUFeature);
        break;
      }
  }
  return FeaturesMask;
}

bool AArch64::getExtensionFeatures(uint64_t InputExts,
                                   std::vector<StringRef> &Features) {
  for (const auto &E : Extensions)
    /* INVALID and NONE have no feature name. */
    if ((InputExts & E.ID) && !E.Feature.empty())
      Features.push_back(E.Feature);

  return true;
}

StringRef AArch64::resolveCPUAlias(StringRef Name) {
  for (const auto &A : CpuAliases)
    if (A.Alias == Name)
      return A.Name;
  return Name;
}

StringRef AArch64::getArchExtFeature(StringRef ArchExt) {
  if (ArchExt.startswith("no")) {
    StringRef ArchExtBase(ArchExt.substr(2));
    for (const auto &AE : Extensions) {
      if (!AE.NegFeature.empty() && ArchExtBase == AE.Name)
        return AE.NegFeature;
    }
  }

  for (const auto &AE : Extensions)
    if (!AE.Feature.empty() && ArchExt == AE.Name)
      return AE.Feature;
  return StringRef();
}

void AArch64::fillValidCPUArchList(SmallVectorImpl<StringRef> &Values) {
  for (const auto &C : CpuInfos)
      Values.push_back(C.Name);

  for (const auto &Alias : CpuAliases)
    Values.push_back(Alias.Alias);
}

bool AArch64::isX18ReservedByDefault(const Triple &TT) {
  return TT.isAndroid() || TT.isOSDarwin() || TT.isOSFuchsia() ||
         TT.isOSWindows();
}

// Allows partial match, ex. "v8a" matches "armv8a".
std::optional<AArch64::ArchInfo> AArch64::parseArch(StringRef Arch) {
  Arch = llvm::ARM::getCanonicalArchName(Arch);
  if (checkArchVersion(Arch) < 8)
    return {};

  StringRef Syn = llvm::ARM::getArchSynonym(Arch);
  for (const auto *A : ArchInfos) {
    if (A->Name.endswith(Syn))
      return *A;
  }
  return {};
}

std::optional<AArch64::ExtensionInfo> AArch64::parseArchExtension(StringRef ArchExt) {
  for (const auto &A : Extensions) {
    if (ArchExt == A.Name)
      return A;
  }
  return {};
}

std::optional<AArch64::CpuInfo> AArch64::parseCpu(StringRef Name) {
  // Resolve aliases first.
  Name = resolveCPUAlias(Name);

  // Then find the CPU name.
  for (const auto &C : CpuInfos)
    if (Name == C.Name)
      return C;

  return {};
}