llvm/lib/Target/TargetMachineRegistry.cpp
2007-12-29 20:36:04 +00:00

86 lines
3.5 KiB
C++

//===-- TargetMachineRegistry.cpp - Target Auto Registration Impl ---------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file exposes the RegisterTarget class, which TargetMachine
// implementations should use to register themselves with the system. This file
// also exposes the TargetMachineRegistry class, which allows tools to inspect
// all of registered targets.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetMachineRegistry.h"
#include <algorithm>
using namespace llvm;
template<> Registry<TargetMachine>::node *Registry<TargetMachine>::Head = 0;
template<> Registry<TargetMachine>::node *Registry<TargetMachine>::Tail = 0;
template<> Registry<TargetMachine>::listener *Registry<TargetMachine>::
ListenerHead = 0;
template<> Registry<TargetMachine>::listener *Registry<TargetMachine>::
ListenerTail = 0;
/// getClosestStaticTargetForModule - Given an LLVM module, pick the best target
/// that is compatible with the module. If no close target can be found, this
/// returns null and sets the Error string to a reason.
const TargetMachineRegistry::entry *
TargetMachineRegistry::getClosestStaticTargetForModule(const Module &M,
std::string &Error) {
std::vector<std::pair<unsigned, const entry *> > UsableTargets;
for (Registry<TargetMachine>::iterator I = begin(), E = end(); I != E; ++I)
if (unsigned Qual = I->ModuleMatchQualityFn(M))
UsableTargets.push_back(std::make_pair(Qual, &*I));
if (UsableTargets.empty()) {
Error = "No available targets are compatible with this module";
return 0;
} else if (UsableTargets.size() == 1)
return UsableTargets.back().second;
// Otherwise, take the best target, but make sure we don't have to equally
// good best targets.
std::sort(UsableTargets.begin(), UsableTargets.end());
if (UsableTargets.back().first ==UsableTargets[UsableTargets.size()-2].first){
Error = "Cannot choose between targets \"" +
std::string(UsableTargets.back().second->Name) + "\" and \"" +
std::string(UsableTargets[UsableTargets.size()-2].second->Name) + "\"";
return 0;
}
return UsableTargets.back().second;
}
/// getClosestTargetForJIT - Pick the best target that is compatible with
/// the current host. If no close target can be found, this returns null
/// and sets the Error string to a reason.
const TargetMachineRegistry::entry *
TargetMachineRegistry::getClosestTargetForJIT(std::string &Error) {
std::vector<std::pair<unsigned, const entry *> > UsableTargets;
for (Registry<TargetMachine>::iterator I = begin(), E = end(); I != E; ++I)
if (unsigned Qual = I->JITMatchQualityFn())
UsableTargets.push_back(std::make_pair(Qual, &*I));
if (UsableTargets.empty()) {
Error = "No JIT is available for this host";
return 0;
} else if (UsableTargets.size() == 1)
return UsableTargets.back().second;
// Otherwise, take the best target. If there is a tie, just pick one.
unsigned MaxQual = UsableTargets.front().first;
const entry *MaxQualTarget = UsableTargets.front().second;
for (unsigned i = 1, e = UsableTargets.size(); i != e; ++i)
if (UsableTargets[i].first > MaxQual) {
MaxQual = UsableTargets[i].first;
MaxQualTarget = UsableTargets[i].second;
}
return MaxQualTarget;
}