llvm-6502/include/llvm/MC/SubtargetFeature.h
John Brawn c1c9bc1df7 [ARM] Add knowledge of FPU subtarget features to TargetParser
Add getFPUFeatures to TargetParser, which gets the list of subtarget features
that are enabled/disabled for each FPU, and use it when handling the .fpu
directive.

No functional change in this commit, though clang will start behaving
differently once it starts using this.

Differential Revision: http://reviews.llvm.org/D10237


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239150 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-05 13:29:24 +00:00

128 lines
4.3 KiB
C++

//===-- llvm/MC/SubtargetFeature.h - CPU characteristics --------*- 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 and manages user or tool specified CPU characteristics.
// The intent is to be able to package specific features that should or should
// not be used on a specific target processor. A tool, such as llc, could, as
// as example, gather chip info from the command line, a long with features
// that should be used on that chip.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MC_SUBTARGETFEATURE_H
#define LLVM_MC_SUBTARGETFEATURE_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Support/DataTypes.h"
#include <bitset>
namespace llvm {
class raw_ostream;
class StringRef;
// A container class for subtarget features.
// This is convenient because std::bitset does not have a constructor
// with an initializer list of set bits.
const unsigned MAX_SUBTARGET_FEATURES = 64;
class FeatureBitset : public std::bitset<MAX_SUBTARGET_FEATURES> {
public:
// Cannot inherit constructors because it's not supported by VC++..
FeatureBitset() : bitset() {}
FeatureBitset(const bitset<MAX_SUBTARGET_FEATURES>& B) : bitset(B) {}
FeatureBitset(std::initializer_list<unsigned> Init) : bitset() {
for (auto I = Init.begin() , E = Init.end(); I != E; ++I)
set(*I);
}
};
//===----------------------------------------------------------------------===//
///
/// SubtargetFeatureKV - Used to provide key value pairs for feature and
/// CPU bit flags.
//
struct SubtargetFeatureKV {
const char *Key; // K-V key string
const char *Desc; // Help descriptor
FeatureBitset Value; // K-V integer value
FeatureBitset Implies; // K-V bit mask
// Compare routine for std::lower_bound
bool operator<(StringRef S) const {
return StringRef(Key) < S;
}
};
//===----------------------------------------------------------------------===//
///
/// SubtargetInfoKV - Used to provide key value pairs for CPU and arbitrary
/// pointers.
//
struct SubtargetInfoKV {
const char *Key; // K-V key string
const void *Value; // K-V pointer value
// Compare routine for std::lower_bound
bool operator<(StringRef S) const {
return StringRef(Key) < S;
}
};
//===----------------------------------------------------------------------===//
///
/// SubtargetFeatures - Manages the enabling and disabling of subtarget
/// specific features. Features are encoded as a string of the form
/// "+attr1,+attr2,-attr3,...,+attrN"
/// A comma separates each feature from the next (all lowercase.)
/// Each of the remaining features is prefixed with + or - indicating whether
/// that feature should be enabled or disabled contrary to the cpu
/// specification.
///
class SubtargetFeatures {
std::vector<std::string> Features; // Subtarget features as a vector
public:
explicit SubtargetFeatures(StringRef Initial = "");
/// Features string accessors.
std::string getString() const;
/// Adding Features.
void AddFeature(StringRef String, bool Enable = true);
/// ToggleFeature - Toggle a feature and returns the newly updated feature
/// bits.
FeatureBitset ToggleFeature(FeatureBitset Bits, StringRef String,
ArrayRef<SubtargetFeatureKV> FeatureTable);
/// Apply the feature flag and return the newly updated feature bits.
FeatureBitset ApplyFeatureFlag(FeatureBitset Bits, StringRef Feature,
ArrayRef<SubtargetFeatureKV> FeatureTable);
/// Get feature bits of a CPU.
FeatureBitset getFeatureBits(StringRef CPU,
ArrayRef<SubtargetFeatureKV> CPUTable,
ArrayRef<SubtargetFeatureKV> FeatureTable);
/// Print feature string.
void print(raw_ostream &OS) const;
// Dump feature info.
void dump() const;
/// Adds the default features for the specified target triple.
void getDefaultSubtargetFeatures(const Triple& Triple);
};
} // End namespace llvm
#endif