From 823d9914a14efd9319f15945241c273cc0b34286 Mon Sep 17 00:00:00 2001
From: Stuart Hastings <stuart@apple.com>
Date: Wed, 15 Jul 2009 18:30:44 +0000
Subject: [PATCH] Restore file lost during reversion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75807 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/TargetMachineRegistry.cpp | 78 ++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 lib/Target/TargetMachineRegistry.cpp

diff --git a/lib/Target/TargetMachineRegistry.cpp b/lib/Target/TargetMachineRegistry.cpp
new file mode 100644
index 00000000000..c1a4777c631
--- /dev/null
+++ b/lib/Target/TargetMachineRegistry.cpp
@@ -0,0 +1,78 @@
+//===-- 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;
+
+/// 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 two 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;
+}
+
-- 
2.34.1