1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 19:23:23 +01:00
llvm-mirror/lib/ExecutionEngine/TargetSelect.cpp
Owen Anderson 7da86bf59f Make it feasible for clients using EngineBuilder to capture the TargetMachine that is created as part of selecting the appropriate target.
This is necessary if the client wants to be able to mutate TargetOptions (for example, fast FP math mode) after the initial creation of the ExecutionEngine.

llvm-svn: 153342
2012-03-23 17:40:56 +00:00

97 lines
3.3 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 target to use, and
// allows the user to specify a specific one on the commandline with -march=x,
// -mcpu=y, and -mattr=a,-b,+c. Clients should initialize targets prior to
// calling selectTarget().
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/Module.h"
#include "llvm/ADT/Triple.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/TargetRegistry.h"
using namespace llvm;
TargetMachine *EngineBuilder::selectTarget() {
StringRef MArch = "";
StringRef MCPU = "";
SmallVector<std::string, 1> MAttrs;
Triple TT(M->getTargetTriple());
return selectTarget(TT, MArch, MCPU, MAttrs);
}
/// 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(const Triple &TargetTriple,
StringRef MArch,
StringRef MCPU,
const SmallVectorImpl<std::string>& MAttrs) {
Triple TheTriple(TargetTriple);
if (TheTriple.getTriple().empty())
TheTriple.setTriple(sys::getDefaultTargetTriple());
// 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
// requested/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;
}
}
// 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,
Options,
RelocModel, CMModel,
OptLevel);
assert(Target && "Could not allocate target machine!");
return Target;
}