llvm-6502/include/llvm/MDBuilder.h
2012-07-15 23:45:20 +00:00

142 lines
5.1 KiB
C++

//===---- llvm/MDBuilder.h - Builder for LLVM metadata ----------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the MDBuilder class, which is used as a convenient way to
// create LLVM metadata with a consistent and simplified interface.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MDBUILDER_H
#define LLVM_MDBUILDER_H
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/LLVMContext.h"
#include "llvm/Metadata.h"
#include "llvm/ADT/APInt.h"
namespace llvm {
class MDBuilder {
LLVMContext &Context;
public:
MDBuilder(LLVMContext &context) : Context(context) {}
/// \brief Return the given string as metadata.
MDString *createString(StringRef Str) {
return MDString::get(Context, Str);
}
//===------------------------------------------------------------------===//
// FPMath metadata.
//===------------------------------------------------------------------===//
/// \brief Return metadata with the given settings. The special value 0.0
/// for the Accuracy parameter indicates the default (maximal precision)
/// setting.
MDNode *createFPMath(float Accuracy) {
if (Accuracy == 0.0)
return 0;
assert(Accuracy > 0.0 && "Invalid fpmath accuracy!");
Value *Op = ConstantFP::get(Type::getFloatTy(Context), Accuracy);
return MDNode::get(Context, Op);
}
//===------------------------------------------------------------------===//
// Prof metadata.
//===------------------------------------------------------------------===//
/// \brief Return metadata containing two branch weights.
MDNode *createBranchWeights(uint32_t TrueWeight, uint32_t FalseWeight) {
uint32_t Weights[] = { TrueWeight, FalseWeight };
return createBranchWeights(Weights);
}
/// \brief Return metadata containing a number of branch weights.
MDNode *createBranchWeights(ArrayRef<uint32_t> Weights) {
assert(Weights.size() >= 2 && "Need at least two branch weights!");
SmallVector<Value *, 4> Vals(Weights.size()+1);
Vals[0] = createString("branch_weights");
Type *Int32Ty = Type::getInt32Ty(Context);
for (unsigned i = 0, e = Weights.size(); i != e; ++i)
Vals[i+1] = ConstantInt::get(Int32Ty, Weights[i]);
return MDNode::get(Context, Vals);
}
//===------------------------------------------------------------------===//
// Range metadata.
//===------------------------------------------------------------------===//
/// \brief Return metadata describing the range [Lo, Hi).
MDNode *createRange(const APInt &Lo, const APInt &Hi) {
assert(Lo.getBitWidth() == Hi.getBitWidth() && "Mismatched bitwidths!");
// If the range is everything then it is useless.
if (Hi == Lo)
return 0;
// Return the range [Lo, Hi).
Type *Ty = IntegerType::get(Context, Lo.getBitWidth());
Value *Range[2] = { ConstantInt::get(Ty, Lo), ConstantInt::get(Ty, Hi) };
return MDNode::get(Context, Range);
}
//===------------------------------------------------------------------===//
// TBAA metadata.
//===------------------------------------------------------------------===//
/// \brief Return metadata appropriate for a TBAA root node. Each returned
/// node is distinct from all other metadata and will never be identified
/// (uniqued) with anything else.
MDNode *createAnonymousTBAARoot() {
// To ensure uniqueness the root node is self-referential.
MDNode *Dummy = MDNode::getTemporary(Context, ArrayRef<Value*>());
MDNode *Root = MDNode::get(Context, Dummy);
// At this point we have
// !0 = metadata !{} <- dummy
// !1 = metadata !{metadata !0} <- root
// Replace the dummy operand with the root node itself and delete the dummy.
Root->replaceOperandWith(0, Root);
MDNode::deleteTemporary(Dummy);
// We now have
// !1 = metadata !{metadata !1} <- self-referential root
return Root;
}
/// \brief Return metadata appropriate for a TBAA root node with the given
/// name. This may be identified (uniqued) with other roots with the same
/// name.
MDNode *createTBAARoot(StringRef Name) {
return MDNode::get(Context, createString(Name));
}
/// \brief Return metadata for a non-root TBAA node with the given name,
/// parent in the TBAA tree, and value for 'pointsToConstantMemory'.
MDNode *createTBAANode(StringRef Name, MDNode *Parent,
bool isConstant = false) {
if (isConstant) {
Constant *Flags = ConstantInt::get(Type::getInt64Ty(Context), 1);
Value *Ops[3] = { createString(Name), Parent, Flags };
return MDNode::get(Context, Ops);
} else {
Value *Ops[2] = { createString(Name), Parent };
return MDNode::get(Context, Ops);
}
}
};
} // end namespace llvm
#endif