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 &, IntrinsicLowering*,
31 unsigned (*MMF)(const Module &M), unsigned (*JMF)())
32 : Name(N), ShortDesc(SD), CtorFn(CF), ModuleMatchQualityFn(MMF),
33 JITMatchQualityFn(JMF), Next(List) {
35 for (TargetRegistrationListener *L = Listeners; L; L = L->getNext())
36 L->targetRegistered(this);
39 TargetRegistrationListener::TargetRegistrationListener() {
41 if (Next) Next->Prev = &Next;
46 TargetRegistrationListener::~TargetRegistrationListener() {
50 /// getClosestStaticTargetForModule - Given an LLVM module, pick the best target
51 /// that is compatible with the module. If no close target can be found, this
52 /// returns null and sets the Error string to a reason.
53 const TargetMachineRegistry::Entry *
54 TargetMachineRegistry::getClosestStaticTargetForModule(const Module &M,
56 std::vector<std::pair<unsigned, const Entry *> > UsableTargets;
57 for (const Entry *E = getList(); E; E = E->getNext())
58 if (unsigned Qual = E->ModuleMatchQualityFn(M))
59 UsableTargets.push_back(std::make_pair(Qual, E));
61 if (UsableTargets.empty()) {
62 Error = "No available targets are compatible with this module";
64 } else if (UsableTargets.size() == 1)
65 return UsableTargets.back().second;
67 // Otherwise, take the best target, but make sure we don't have to equally
69 std::sort(UsableTargets.begin(), UsableTargets.end());
70 if (UsableTargets.back().first ==UsableTargets[UsableTargets.size()-2].first){
71 Error = "Cannot choose between targets \"" +
72 std::string(UsableTargets.back().second->Name) + "\" and \"" +
73 std::string(UsableTargets[UsableTargets.size()-2].second->Name) + "\"";
76 return UsableTargets.back().second;
79 /// getClosestTargetForJIT - Given an LLVM module, pick the best target that
80 /// is compatible with the current host and the specified module. If no
81 /// close target can be found, this returns null and sets the Error string
83 const TargetMachineRegistry::Entry *
84 TargetMachineRegistry::getClosestTargetForJIT(std::string &Error) {
85 std::vector<std::pair<unsigned, const Entry *> > UsableTargets;
86 for (const Entry *E = getList(); E; E = E->getNext())
87 if (unsigned Qual = E->JITMatchQualityFn())
88 UsableTargets.push_back(std::make_pair(Qual, E));
90 if (UsableTargets.empty()) {
91 Error = "No JIT is available for this host";
93 } else if (UsableTargets.size() == 1)
94 return UsableTargets.back().second;
96 // Otherwise, take the best target. If there is a tie, just pick one.
97 unsigned MaxQual = UsableTargets.front().first;
98 const Entry *MaxQualTarget = UsableTargets.front().second;
100 for (unsigned i = 1, e = UsableTargets.size(); i != e; ++i)
101 if (UsableTargets[i].first > MaxQual) {
102 MaxQual = UsableTargets[i].first;
103 MaxQualTarget = UsableTargets[i].second;
106 return MaxQualTarget;