llvm/lib/ExecutionEngine/TargetSelect.cpp
Evan Cheng 276365dd4b Fix the ridiculous SubtargetFeatures API where it implicitly expects CPU name to
be the first encoded as the first feature. It then uses the CPU name to look up
features / scheduling itineray even though clients know full well the CPU name
being used to query these properties.

The fix is to just have the clients explictly pass the CPU name!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134127 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-30 01:53:36 +00:00

91 lines
3.1 KiB
C++

//===-- 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/MC/SubtargetFeature.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Host.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 *EngineBuilder::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 (!MAttrs.empty()) {
SubtargetFeatures Features;
for (unsigned i = 0; i != MAttrs.size(); ++i)
Features.AddFeature(MAttrs[i]);
FeaturesStr = Features.getString();
}
// Allocate a target...
TargetMachine *Target =
TheTarget->createTargetMachine(TheTriple.getTriple(), MCPU, FeaturesStr);
assert(Target && "Could not allocate target machine!");
return Target;
}