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/MC/SubtargetFeature.h" 14 #include "llvm/ADT/SmallVector.h" 15 #include "llvm/ADT/StringExtras.h" 16 #include "llvm/ADT/StringRef.h" 17 #include "llvm/ADT/Triple.h" 18 #include "llvm/Config/llvm-config.h" 19 #include "llvm/Support/Compiler.h" 20 #include "llvm/Support/Debug.h" 21 #include "llvm/Support/raw_ostream.h" 22 #include <algorithm> 23 #include <cassert> 24 #include <cstddef> 25 #include <cstring> 26 #include <iterator> 27 #include <string> 28 #include <vector> 29 30 using namespace llvm; 31 32 /// Splits a string of comma separated items in to a vector of strings. 33 void SubtargetFeatures::Split(std::vector<std::string> &V, StringRef S) { 34 SmallVector<StringRef, 3> Tmp; 35 S.split(Tmp, ',', -1, false /* KeepEmpty */); 36 V.assign(Tmp.begin(), Tmp.end()); 37 } 38 39 void SubtargetFeatures::AddFeature(StringRef String, bool Enable) { 40 // Don't add empty features. 41 if (!String.empty()) 42 // Convert to lowercase, prepend flag if we don't already have a flag. 43 Features.push_back(hasFlag(String) ? String.lower() 44 : (Enable ? "+" : "-") + String.lower()); 45 } 46 47 SubtargetFeatures::SubtargetFeatures(StringRef Initial) { 48 // Break up string into separate features 49 Split(Features, Initial); 50 } 51 52 std::string SubtargetFeatures::getString() const { 53 return join(Features.begin(), Features.end(), ","); 54 } 55 56 void SubtargetFeatures::print(raw_ostream &OS) const { 57 for (auto &F : Features) 58 OS << F << " "; 59 OS << "\n"; 60 } 61 62 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 63 LLVM_DUMP_METHOD void SubtargetFeatures::dump() const { 64 print(dbgs()); 65 } 66 #endif 67 68 void SubtargetFeatures::getDefaultSubtargetFeatures(const Triple& Triple) { 69 // FIXME: This is an inelegant way of specifying the features of a 70 // subtarget. It would be better if we could encode this information 71 // into the IR. See <rdar://5972456>. 72 if (Triple.getVendor() == Triple::Apple) { 73 if (Triple.getArch() == Triple::ppc) { 74 // powerpc-apple-* 75 AddFeature("altivec"); 76 } else if (Triple.getArch() == Triple::ppc64) { 77 // powerpc64-apple-* 78 AddFeature("64bit"); 79 AddFeature("altivec"); 80 } 81 } 82 } 83