1 //===-- TargetMachineRegistry.cpp - Target Auto Registration Impl ---------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file exposes the RegisterTarget class, which TargetMachine
11 // implementations should use to register themselves with the system. This file
12 // also exposes the TargetMachineRegistry class, which allows tools to inspect
13 // all of registered targets.
15 //===----------------------------------------------------------------------===//
17 #include "llvm/Target/TargetMachineRegistry.h"
21 /// List - This is the main list of all of the registered target machines.
22 const TargetMachineRegistry::Entry *TargetMachineRegistry::List = 0;
24 /// Listeners - All of the listeners registered to get notified when new targets
26 static TargetRegistrationListener *Listeners = 0;
28 TargetMachineRegistry::Entry::Entry(const char *N, const char *SD,
29 TargetMachine *(*CF)(const Module &,const std::string &),
30 unsigned (*MMF)(const Module &M), unsigned (*JMF)())
31 : Name(N), ShortDesc(SD), CtorFn(CF), ModuleMatchQualityFn(MMF),
32 JITMatchQualityFn(JMF), Next(List) {
34 for (TargetRegistrationListener *L = Listeners; L; L = L->getNext())
35 L->targetRegistered(this);
38 TargetRegistrationListener::TargetRegistrationListener() {
40 if (Next) Next->Prev = &Next;
45 TargetRegistrationListener::~TargetRegistrationListener() {
49 /// getClosestStaticTargetForModule - Given an LLVM module, pick the best target
50 /// that is compatible with the module. If no close target can be found, this
51 /// returns null and sets the Error string to a reason.
52 const TargetMachineRegistry::Entry *
53 TargetMachineRegistry::getClosestStaticTargetForModule(const Module &M,
55 std::vector<std::pair<unsigned, const Entry *> > UsableTargets;
56 for (const Entry *E = getList(); E; E = E->getNext())
57 if (unsigned Qual = E->ModuleMatchQualityFn(M))
58 UsableTargets.push_back(std::make_pair(Qual, E));
60 if (UsableTargets.empty()) {
61 Error = "No available targets are compatible with this module";
63 } else if (UsableTargets.size() == 1)
64 return UsableTargets.back().second;
66 // Otherwise, take the best target, but make sure we don't have to equally
68 std::sort(UsableTargets.begin(), UsableTargets.end());
69 if (UsableTargets.back().first ==UsableTargets[UsableTargets.size()-2].first){
70 Error = "Cannot choose between targets \"" +
71 std::string(UsableTargets.back().second->Name) + "\" and \"" +
72 std::string(UsableTargets[UsableTargets.size()-2].second->Name) + "\"";
75 return UsableTargets.back().second;
78 /// getClosestTargetForJIT - Pick the best target that is compatible with
79 /// the current host. If no close target can be found, this returns null
80 /// and sets the Error string to a reason.
81 const TargetMachineRegistry::Entry *
82 TargetMachineRegistry::getClosestTargetForJIT(std::string &Error) {
83 std::vector<std::pair<unsigned, const Entry *> > UsableTargets;
84 for (const Entry *E = getList(); E; E = E->getNext())
85 if (unsigned Qual = E->JITMatchQualityFn())
86 UsableTargets.push_back(std::make_pair(Qual, E));
88 if (UsableTargets.empty()) {
89 Error = "No JIT is available for this host";
91 } else if (UsableTargets.size() == 1)
92 return UsableTargets.back().second;
94 // Otherwise, take the best target. If there is a tie, just pick one.
95 unsigned MaxQual = UsableTargets.front().first;
96 const Entry *MaxQualTarget = UsableTargets.front().second;
98 for (unsigned i = 1, e = UsableTargets.size(); i != e; ++i)
99 if (UsableTargets[i].first > MaxQual) {
100 MaxQual = UsableTargets[i].first;
101 MaxQualTarget = UsableTargets[i].second;
104 return MaxQualTarget;