llvm/lib/TargetParser/SubtargetFeature.cpp

   1 //===- SubtargetFeature.cpp - CPU characteristics Implementation ----------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 /// \file Implements the SubtargetFeature interface.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/TargetParser/SubtargetFeature.h"
  14 #include "llvm/ADT/SmallVector.h"
  15 #include "llvm/ADT/StringExtras.h"
  16 #include "llvm/ADT/StringRef.h"
  17 #include "llvm/Config/llvm-config.h"
  18 #include "llvm/Support/Compiler.h"
  19 #include "llvm/Support/Debug.h"
  20 #include "llvm/Support/raw_ostream.h"
  21 #include "llvm/TargetParser/Triple.h"
  22 #include <algorithm>
  23 #include <string>
  24 #include <vector>
  25
  26 using namespace llvm;
  27
  28 /// Splits a string of comma separated items in to a vector of strings.
  29 void SubtargetFeatures::Split(std::vector<std::string> &V, StringRef S) {
  30   SmallVector<StringRef, 3> Tmp;
  31   S.split(Tmp, ',', -1, false /* KeepEmpty */);
  32   V.reserve(Tmp.size());
  33   for (StringRef T : Tmp)
  34     V.push_back(std::string(T));
  35 }
  36
  37 void SubtargetFeatures::AddFeature(StringRef String, bool Enable) {
  38   // Don't add empty features.
  39   if (!String.empty())
  40     // Convert to lowercase, prepend flag if we don't already have a flag.
  41     Features.push_back(hasFlag(String) ? String.lower()
  42                                        : (Enable ? "+" : "-") + String.lower());
  43 }
  44
  45 void SubtargetFeatures::addFeaturesVector(
  46     const ArrayRef<std::string> OtherFeatures) {
  47   Features.insert(Features.cend(), OtherFeatures.begin(), OtherFeatures.end());
  48 }
  49
  50 SubtargetFeatures::SubtargetFeatures(StringRef Initial) {
  51   // Break up string into separate features
  52   Split(Features, Initial);
  53 }
  54
  55 std::string SubtargetFeatures::getString() const {
  56   return join(Features.begin(), Features.end(), ",");
  57 }
  58
  59 void SubtargetFeatures::print(raw_ostream &OS) const {
  60   for (const auto &F : Features)
  61     OS << F << " ";
  62   OS << "\n";
  63 }
  64
  65 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
  66 LLVM_DUMP_METHOD void SubtargetFeatures::dump() const {
  67   print(dbgs());
  68 }
  69 #endif
  70
  71 void SubtargetFeatures::getDefaultSubtargetFeatures(const Triple& Triple) {
  72   // FIXME: This is an inelegant way of specifying the features of a
  73   // subtarget. It would be better if we could encode this information
  74   // into the IR.
  75   if (Triple.getVendor() == Triple::Apple) {
  76     if (Triple.getArch() == Triple::ppc) {
  77       // powerpc-apple-*
  78       AddFeature("altivec");
  79     } else if (Triple.getArch() == Triple::ppc64) {
  80       // powerpc64-apple-*
  81       AddFeature("64bit");
  82       AddFeature("altivec");
  83     }
  84   }
  85 }