mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-25 12:12:47 +01:00
259 lines
8.7 KiB
C++
259 lines
8.7 KiB
C++
//===-- ConstantRange.cpp - ConstantRange implementation ------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file was developed by the LLVM research group and is distributed under
|
|
// the University of Illinois Open Source License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Represent a range of possible values that may occur when the program is run
|
|
// for an integral value. This keeps track of a lower and upper bound for the
|
|
// constant, which MAY wrap around the end of the numeric range. To do this, it
|
|
// keeps track of a [lower, upper) bound, which specifies an interval just like
|
|
// STL iterators. When used with boolean values, the following are important
|
|
// ranges (other integral ranges use min/max values for special range values):
|
|
//
|
|
// [F, F) = {} = Empty set
|
|
// [T, F) = {T}
|
|
// [F, T) = {F}
|
|
// [T, T) = {F, T} = Full set
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Support/ConstantRange.h"
|
|
#include "llvm/Constants.h"
|
|
#include "llvm/Instruction.h"
|
|
#include "llvm/Type.h"
|
|
using namespace llvm;
|
|
|
|
static bool LT(ConstantIntegral *A, ConstantIntegral *B) {
|
|
Constant *C = ConstantExpr::get(Instruction::SetLT, A, B);
|
|
assert(isa<ConstantBool>(C) && "Constant folding of integrals not impl??");
|
|
return cast<ConstantBool>(C)->getValue();
|
|
}
|
|
|
|
static bool GT(ConstantIntegral *A, ConstantIntegral *B) {
|
|
Constant *C = ConstantExpr::get(Instruction::SetGT, A, B);
|
|
assert(isa<ConstantBool>(C) && "Constant folding of integrals not impl??");
|
|
return cast<ConstantBool>(C)->getValue();
|
|
}
|
|
|
|
static ConstantIntegral *Min(ConstantIntegral *A, ConstantIntegral *B) {
|
|
return LT(A, B) ? A : B;
|
|
}
|
|
static ConstantIntegral *Max(ConstantIntegral *A, ConstantIntegral *B) {
|
|
return GT(A, B) ? A : B;
|
|
}
|
|
|
|
|
|
/// Initialize a full (the default) or empty set for the specified type.
|
|
///
|
|
ConstantRange::ConstantRange(const Type *Ty, bool Full) {
|
|
assert(Ty->isIntegral() &&
|
|
"Cannot make constant range of non-integral type!");
|
|
if (Full)
|
|
Lower = Upper = ConstantIntegral::getMaxValue(Ty);
|
|
else
|
|
Lower = Upper = ConstantIntegral::getMinValue(Ty);
|
|
}
|
|
|
|
/// Initialize a range of values explicitly... this will assert out if
|
|
/// Lower==Upper and Lower != Min or Max for its type (or if the two constants
|
|
/// have different types)
|
|
///
|
|
ConstantRange::ConstantRange(ConstantIntegral *L,
|
|
ConstantIntegral *U) : Lower(L), Upper(U) {
|
|
assert(Lower->getType() == Upper->getType() &&
|
|
"Incompatible types for ConstantRange!");
|
|
|
|
// Make sure that if L & U are equal that they are either Min or Max...
|
|
assert((L != U || (L == ConstantIntegral::getMaxValue(L->getType()) ||
|
|
L == ConstantIntegral::getMinValue(L->getType()))) &&
|
|
"Lower == Upper, but they aren't min or max for type!");
|
|
}
|
|
|
|
static ConstantIntegral *Next(ConstantIntegral *CI) {
|
|
if (CI->getType() == Type::BoolTy)
|
|
return CI == ConstantBool::True ? ConstantBool::False : ConstantBool::True;
|
|
|
|
Constant *Result = ConstantExpr::get(Instruction::Add, CI,
|
|
ConstantInt::get(CI->getType(), 1));
|
|
return cast<ConstantIntegral>(Result);
|
|
}
|
|
|
|
/// Initialize a set of values that all satisfy the condition with C.
|
|
///
|
|
ConstantRange::ConstantRange(unsigned SetCCOpcode, ConstantIntegral *C) {
|
|
switch (SetCCOpcode) {
|
|
default: assert(0 && "Invalid SetCC opcode to ConstantRange ctor!");
|
|
case Instruction::SetEQ: Lower = C; Upper = Next(C); return;
|
|
case Instruction::SetNE: Upper = C; Lower = Next(C); return;
|
|
case Instruction::SetLT:
|
|
Lower = ConstantIntegral::getMinValue(C->getType());
|
|
Upper = C;
|
|
return;
|
|
case Instruction::SetGT:
|
|
Lower = Next(C);
|
|
Upper = ConstantIntegral::getMinValue(C->getType()); // Min = Next(Max)
|
|
return;
|
|
case Instruction::SetLE:
|
|
Lower = ConstantIntegral::getMinValue(C->getType());
|
|
Upper = Next(C);
|
|
return;
|
|
case Instruction::SetGE:
|
|
Lower = C;
|
|
Upper = ConstantIntegral::getMinValue(C->getType()); // Min = Next(Max)
|
|
return;
|
|
}
|
|
}
|
|
|
|
/// getType - Return the LLVM data type of this range.
|
|
///
|
|
const Type *ConstantRange::getType() const { return Lower->getType(); }
|
|
|
|
/// isFullSet - Return true if this set contains all of the elements possible
|
|
/// for this data-type
|
|
bool ConstantRange::isFullSet() const {
|
|
return Lower == Upper && Lower == ConstantIntegral::getMaxValue(getType());
|
|
}
|
|
|
|
/// isEmptySet - Return true if this set contains no members.
|
|
///
|
|
bool ConstantRange::isEmptySet() const {
|
|
return Lower == Upper && Lower == ConstantIntegral::getMinValue(getType());
|
|
}
|
|
|
|
/// isWrappedSet - Return true if this set wraps around the top of the range,
|
|
/// for example: [100, 8)
|
|
///
|
|
bool ConstantRange::isWrappedSet() const {
|
|
return GT(Lower, Upper);
|
|
}
|
|
|
|
|
|
/// getSingleElement - If this set contains a single element, return it,
|
|
/// otherwise return null.
|
|
ConstantIntegral *ConstantRange::getSingleElement() const {
|
|
if (Upper == Next(Lower)) // Is it a single element range?
|
|
return Lower;
|
|
return 0;
|
|
}
|
|
|
|
/// getSetSize - Return the number of elements in this set.
|
|
///
|
|
uint64_t ConstantRange::getSetSize() const {
|
|
if (isEmptySet()) return 0;
|
|
if (getType() == Type::BoolTy) {
|
|
if (Lower != Upper) // One of T or F in the set...
|
|
return 1;
|
|
return 2; // Must be full set...
|
|
}
|
|
|
|
// Simply subtract the bounds...
|
|
Constant *Result =
|
|
ConstantExpr::get(Instruction::Sub, (Constant*)Upper, (Constant*)Lower);
|
|
return cast<ConstantInt>(Result)->getRawValue();
|
|
}
|
|
|
|
|
|
|
|
|
|
// intersect1Wrapped - This helper function is used to intersect two ranges when
|
|
// it is known that LHS is wrapped and RHS isn't.
|
|
//
|
|
static ConstantRange intersect1Wrapped(const ConstantRange &LHS,
|
|
const ConstantRange &RHS) {
|
|
assert(LHS.isWrappedSet() && !RHS.isWrappedSet());
|
|
|
|
// Check to see if we overlap on the Left side of RHS...
|
|
//
|
|
if (LT(RHS.getLower(), LHS.getUpper())) {
|
|
// We do overlap on the left side of RHS, see if we overlap on the right of
|
|
// RHS...
|
|
if (GT(RHS.getUpper(), LHS.getLower())) {
|
|
// Ok, the result overlaps on both the left and right sides. See if the
|
|
// resultant interval will be smaller if we wrap or not...
|
|
//
|
|
if (LHS.getSetSize() < RHS.getSetSize())
|
|
return LHS;
|
|
else
|
|
return RHS;
|
|
|
|
} else {
|
|
// No overlap on the right, just on the left.
|
|
return ConstantRange(RHS.getLower(), LHS.getUpper());
|
|
}
|
|
|
|
} else {
|
|
// We don't overlap on the left side of RHS, see if we overlap on the right
|
|
// of RHS...
|
|
if (GT(RHS.getUpper(), LHS.getLower())) {
|
|
// Simple overlap...
|
|
return ConstantRange(LHS.getLower(), RHS.getUpper());
|
|
} else {
|
|
// No overlap...
|
|
return ConstantRange(LHS.getType(), false);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// intersect - Return the range that results from the intersection of this
|
|
/// range with another range.
|
|
///
|
|
ConstantRange ConstantRange::intersectWith(const ConstantRange &CR) const {
|
|
assert(getType() == CR.getType() && "ConstantRange types don't agree!");
|
|
// Handle common special cases
|
|
if (isEmptySet() || CR.isFullSet()) return *this;
|
|
if (isFullSet() || CR.isEmptySet()) return CR;
|
|
|
|
if (!isWrappedSet()) {
|
|
if (!CR.isWrappedSet()) {
|
|
ConstantIntegral *L = Max(Lower, CR.Lower);
|
|
ConstantIntegral *U = Min(Upper, CR.Upper);
|
|
|
|
if (LT(L, U)) // If range isn't empty...
|
|
return ConstantRange(L, U);
|
|
else
|
|
return ConstantRange(getType(), false); // Otherwise, return empty set
|
|
} else
|
|
return intersect1Wrapped(CR, *this);
|
|
} else { // We know "this" is wrapped...
|
|
if (!CR.isWrappedSet())
|
|
return intersect1Wrapped(*this, CR);
|
|
else {
|
|
// Both ranges are wrapped...
|
|
ConstantIntegral *L = Max(Lower, CR.Lower);
|
|
ConstantIntegral *U = Min(Upper, CR.Upper);
|
|
return ConstantRange(L, U);
|
|
}
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
/// union - Return the range that results from the union of this range with
|
|
/// another range. The resultant range is guaranteed to include the elements of
|
|
/// both sets, but may contain more. For example, [3, 9) union [12,15) is [3,
|
|
/// 15), which includes 9, 10, and 11, which were not included in either set
|
|
/// before.
|
|
///
|
|
ConstantRange ConstantRange::unionWith(const ConstantRange &CR) const {
|
|
assert(getType() == CR.getType() && "ConstantRange types don't agree!");
|
|
|
|
assert(0 && "Range union not implemented yet!");
|
|
|
|
return *this;
|
|
}
|
|
|
|
/// print - Print out the bounds to a stream...
|
|
///
|
|
void ConstantRange::print(std::ostream &OS) const {
|
|
OS << "[" << Lower << "," << Upper << " )";
|
|
}
|
|
|
|
/// dump - Allow printing from a debugger easily...
|
|
///
|
|
void ConstantRange::dump() const {
|
|
print(std::cerr);
|
|
}
|