1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-01 16:33:37 +01:00
llvm-mirror/include/llvm/ConstantRangesSet.h
Stepan Dyatkovskiy 33fd2a5bf4 Ordinary patch for PR1255.
Added new case-ranges orientated methods for adding/removing cases in SwitchInst. After this patch cases will internally representated as ConstantArray-s instead of ConstantInt, externally cases wrapped within the ConstantRangesSet object.
Old methods of SwitchInst are also works well, but marked as deprecated. So on this stage we have no side effects except that I added support for case ranges in BitcodeReader/Writer, of course test for Bitcode is also added. Old "switch" format is also supported.

llvm-svn: 156374
2012-05-08 06:36:08 +00:00

287 lines
9.8 KiB
C++

//===-- llvm/ConstantRangesSet.h - The constant set of ranges ---*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// @file
/// This file contains class that implements constant set of ranges:
/// [<Low0,High0>,...,<LowN,HighN>]. Mainly, this set is used by SwitchInst and
/// represents case value that may contain multiple ranges for a single
/// successor.
///
//
//===----------------------------------------------------------------------===//
#ifndef CONSTANTRANGESSET_H_
#define CONSTANTRANGESSET_H_
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
namespace llvm {
class ConstantRangesSet;
template <bool IsReadonly> struct CRSConstantTypes {
typedef ConstantInt ConstantIntTy;
typedef ConstantRangesSet ConstantRangesSetTy;
};
template <>
struct CRSConstantTypes<true> {
typedef const ConstantInt ConstantIntTy;
typedef const ConstantRangesSet ConstantRangesSetTy;
};
//===----------------------------------------------------------------------===//
/// ConstantRangesSet - class that implements constant set of ranges.
/// It is a wrapper for some real "holder" class (currently ConstantArray).
/// It contains functions, that allows to parse "holder" like a set of ranges.
/// Note: It is assumed that "holder" is inherited from Constant object.
/// ConstantRangesSet may be converted to and from Constant* pointer.
///
class ConstantRangesSet {
Constant *Array;
public:
bool IsWide;
// implicit
ConstantRangesSet(Constant *V) : Array(V) {
ArrayType *ArrTy = cast<ArrayType>(Array->getType());
VectorType *VecTy = cast<VectorType>(ArrTy->getElementType());
IntegerType *IntTy = cast<IntegerType>(VecTy->getElementType());
IsWide = IntTy->getBitWidth() > 64;
}
operator Constant*() { return Array; }
operator const Constant*() const { return Array; }
Constant *operator->() { return Array; }
const Constant *operator->() const { return Array; }
template <bool IsReadonly>
struct RangeT {
typedef typename CRSConstantTypes<IsReadonly>::ConstantIntTy ConstantIntTy;
typedef std::pair<RangeT, RangeT> SubRes;
ConstantIntTy *Low;
ConstantIntTy *High;
RangeT() : Low(0), High(0) {}
RangeT(const RangeT<false> &RHS) : Low(RHS.Low), High(RHS.High) {}
RangeT(ConstantIntTy *C) : Low(C), High(C) {}
RangeT(ConstantIntTy *L, ConstantIntTy *H) : Low(L), High(H) {}
bool operator<(const RangeT &RHS) const {
assert(Low && High && "Case range is not initialized.");
assert(RHS.Low && RHS.High && "Right case range is not initialized.");
const APInt &LowInt = Low->getValue();
const APInt &HighInt = High->getValue();
const APInt &RHSLowInt = RHS.Low->getValue();
const APInt &RHSHighInt = RHS.High->getValue();
if (LowInt.getBitWidth() == RHSLowInt.getBitWidth()) {
if (LowInt.eq(RHSLowInt)) {
if (HighInt.ult(RHSHighInt))
return true;
return false;
}
if (LowInt.ult(RHSLowInt))
return true;
return false;
} else
return LowInt.getBitWidth() < RHSLowInt.getBitWidth();
}
bool operator==(const RangeT &RHS) const {
assert(Low && High && "Case range is not initialized.");
assert(RHS.Low && RHS.High && "Right case range is not initialized.");
if (Low->getValue().getBitWidth() != RHS.Low->getValue().getBitWidth())
return false;
return Low->getValue() == RHS.Low->getValue() &&
High->getValue() == RHS.High->getValue();
}
bool operator!=(const RangeT &RHS) const {
return !operator ==(RHS);
}
static bool LessBySize(const RangeT &LHS, const RangeT &RHS) {
assert(LHS.Low->getBitWidth() == RHS.Low->getBitWidth() &&
"This type of comparison requires equal bit width for LHS and RHS");
APInt LSize = LHS.High->getValue() - LHS.Low->getValue();
APInt RSize = RHS.High->getValue() - RHS.Low->getValue();;
return LSize.ult(RSize);
}
bool isInRange(const APInt &IntVal) const {
assert(Low && High && "Case range is not initialized.");
if (IntVal.getBitWidth() != Low->getValue().getBitWidth())
return false;
return IntVal.uge(Low->getValue()) && IntVal.ule(High->getValue());
}
bool isInRange(const ConstantIntTy *CI) const {
const APInt& IntVal = CI->getValue();
return isInRange(IntVal);
}
SubRes sub(const RangeT &RHS) const {
SubRes Res;
// RHS is either more global and includes this range or
// if it doesn't intersected with this range.
if (!isInRange(RHS.Low) && !isInRange(RHS.High)) {
// If RHS more global (it is enough to check
// only one border in this case.
if (RHS.isInRange(Low))
return std::make_pair(RangeT(Low, High), RangeT());
return Res;
}
const APInt& LoInt = Low->getValue();
const APInt& HiInt = High->getValue();
APInt RHSLoInt = RHS.Low->getValue();
APInt RHSHiInt = RHS.High->getValue();
if (LoInt.ult(RHSLoInt)) {
Res.first.Low = Low;
Res.first.High = ConstantIntTy::get(RHS.Low->getContext(), --RHSLoInt);
}
if (HiInt.ugt(RHSHiInt)) {
Res.second.Low = ConstantIntTy::get(RHS.High->getContext(), ++RHSHiInt);
Res.second.High = High;
}
return Res;
}
};
typedef RangeT<false> Range;
/// Checks is the given constant satisfies this case. Returns
/// true if it equals to one of contained values or belongs to the one of
/// contained ranges.
bool isSatisfies(const ConstantInt *C) const {
const APInt &CheckingVal = C->getValue();
for (unsigned i = 0, e = getNumItems(); i < e; ++i) {
const Constant *CV = Array->getAggregateElement(i);
unsigned VecSize = cast<VectorType>(CV->getType())->getNumElements();
switch (VecSize) {
case 1:
if (cast<const ConstantInt>(CV->getAggregateElement(0U))->getValue() ==
CheckingVal)
return true;
break;
case 2: {
const APInt &Lo =
cast<const ConstantInt>(CV->getAggregateElement(0U))->getValue();
const APInt &Hi =
cast<const ConstantInt>(CV->getAggregateElement(1))->getValue();
if (Lo.uge(CheckingVal) && Hi.ule(CheckingVal))
return true;
}
break;
default:
assert(0 && "Only pairs and single numbers are allowed here.");
break;
}
}
return false;
}
/// Returns set's item with given index.
Range getItem(unsigned idx) {
Constant *CV = Array->getAggregateElement(idx);
unsigned NumEls = cast<VectorType>(CV->getType())->getNumElements();
switch (NumEls) {
case 1:
return Range(cast<ConstantInt>(CV->getAggregateElement(0U)),
cast<ConstantInt>(CV->getAggregateElement(0U)));
case 2:
return Range(cast<ConstantInt>(CV->getAggregateElement(0U)),
cast<ConstantInt>(CV->getAggregateElement(1)));
default:
assert(0 && "Only pairs and single numbers are allowed here.");
return Range();
}
}
const Range getItem(unsigned idx) const {
const Constant *CV = Array->getAggregateElement(idx);
unsigned NumEls = cast<VectorType>(CV->getType())->getNumElements();
switch (NumEls) {
case 1:
return Range(cast<ConstantInt>(
const_cast<Constant*>(CV->getAggregateElement(0U))),
cast<ConstantInt>(
const_cast<Constant*>(CV->getAggregateElement(0U))));
case 2:
return Range(cast<ConstantInt>(
const_cast<Constant*>(CV->getAggregateElement(0U))),
cast<ConstantInt>(
const_cast<Constant*>(CV->getAggregateElement(1))));
default:
assert(0 && "Only pairs and single numbers are allowed here.");
return Range();
}
}
/// Return number of items (ranges) stored in set.
unsigned getNumItems() const {
return cast<ArrayType>(Array->getType())->getNumElements();
}
bool isWideNumberFormat() const { return IsWide; }
bool isSingleNumber(unsigned idx) const {
Constant *CV = Array->getAggregateElement(idx);
return cast<VectorType>(CV->getType())->getNumElements() == 1;
}
/// Returns set the size, that equals number of all values + sizes of all
/// ranges.
/// Ranges set is considered as flat numbers collection.
/// E.g.: for range [<0>, <1>, <4,8>] the size will 7;
/// for range [<0>, <1>, <5>] the size will 3
unsigned getSize() const {
APInt sz(getItem(0).Low->getBitWidth(), 0);
for (unsigned i = 0, e = getNumItems(); i != e; ++i) {
const APInt &S = getItem(i).High->getValue() - getItem(i).Low->getValue();
sz += S;
}
return sz.getZExtValue();
}
/// Allows to access single value even if it belongs to some range.
/// Ranges set is considered as flat numbers collection.
/// [<1>, <4,8>] is considered as [1,4,5,6,7,8]
/// For range [<1>, <4,8>] getSingleValue(3) returns 6.
APInt getSingleValue(unsigned idx) const {
APInt sz(getItem(0).Low->getBitWidth(), 0);
for (unsigned i = 0, e = getNumItems(); i != e; ++i) {
const APInt& S = getItem(i).High->getValue() - getItem(i).Low->getValue();
APInt oldSz = sz;
sz += S;
if (oldSz.uge(i) && sz.ult(i)) {
APInt Res = getItem(i).Low->getValue();
APInt Offset(oldSz.getBitWidth(), i);
Offset -= oldSz;
Res += Offset;
return Res;
}
}
assert(0 && "Index exceeds high border.");
return sz;
}
};
}
#endif /* CONSTANTRANGESSET_H_ */