ExecutionEngine: add missing file

From revision 131025.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131029 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 91 insertions, 0 deletions

diff --git a/lib/ExecutionEngine/TargetSelect.cpp b/lib/ExecutionEngine/TargetSelect.cpp
new file mode 100644
index 0000000000..fa5bcd766b
--- /dev/null
+++ b/lib/ExecutionEngine/TargetSelect.cpp
@@ -0,0 +1,91 @@
+//===-- TargetSelect.cpp - Target Chooser Code ----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This just asks the TargetRegistry for the appropriate JIT to use, and allows
+// the user to specify a specific one on the commandline with -march=x. Clients
+// should initialize targets prior to calling createJIT.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/Module.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Target/SubtargetFeature.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetRegistry.h"
+using namespace llvm;
+
+/// selectTarget - Pick a target either via -march or by guessing the native
+/// arch.  Add any CPU features specified via -mcpu or -mattr.
+TargetMachine *ExecutionEngine::selectTarget(Module *Mod,
+                                 StringRef MArch,
+                                 StringRef MCPU,
+                                 const SmallVectorImpl<std::string>& MAttrs,
+                                 std::string *ErrorStr) {
+  Triple TheTriple(Mod->getTargetTriple());
+  if (TheTriple.getTriple().empty())
+    TheTriple.setTriple(sys::getHostTriple());
+
+  // Adjust the triple to match what the user requested.
+  const Target *TheTarget = 0;
+  if (!MArch.empty()) {
+    for (TargetRegistry::iterator it = TargetRegistry::begin(),
+           ie = TargetRegistry::end(); it != ie; ++it) {
+      if (MArch == it->getName()) {
+        TheTarget = &*it;
+        break;
+      }
+    }
+
+    if (!TheTarget) {
+      *ErrorStr = "No available targets are compatible with this -march, "
+        "see -version for the available targets.\n";
+      return 0;
+    }
+
+    // Adjust the triple to match (if known), otherwise stick with the
+    // module/host triple.
+    Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch);
+    if (Type != Triple::UnknownArch)
+      TheTriple.setArch(Type);
+  } else {
+    std::string Error;
+    TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Error);
+    if (TheTarget == 0) {
+      if (ErrorStr)
+        *ErrorStr = Error;
+      return 0;
+    }
+  }
+
+  if (!TheTarget->hasJIT()) {
+    errs() << "WARNING: This target JIT is not designed for the host you are"
+           << " running.  If bad things happen, please choose a different "
+           << "-march switch.\n";
+  }
+
+  // Package up features to be passed to target/subtarget
+  std::string FeaturesStr;
+  if (!MCPU.empty() || !MAttrs.empty()) {
+    SubtargetFeatures Features;
+    Features.setCPU(MCPU);
+    for (unsigned i = 0; i != MAttrs.size(); ++i)
+      Features.AddFeature(MAttrs[i]);
+    FeaturesStr = Features.getString();
+  }
+
+  // Allocate a target...
+  TargetMachine *Target =
+    TheTarget->createTargetMachine(TheTriple.getTriple(), FeaturesStr);
+  assert(Target && "Could not allocate target machine!");
+  return Target;
+}