2009-11-11 08:22:30 +08:00
|
|
|
//===- LazyValueInfo.cpp - Value constraint analysis ----------------------===//
|
|
|
|
//
|
|
|
|
// 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 interface for lazy computation of value constraint
|
|
|
|
// information.
|
|
|
|
//
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
|
2009-11-12 09:22:16 +08:00
|
|
|
#define DEBUG_TYPE "lazy-value-info"
|
2009-11-11 08:22:30 +08:00
|
|
|
#include "llvm/Analysis/LazyValueInfo.h"
|
2012-12-04 00:50:05 +08:00
|
|
|
#include "llvm/ADT/DenseSet.h"
|
|
|
|
#include "llvm/ADT/STLExtras.h"
|
|
|
|
#include "llvm/Analysis/AliasAnalysis.h"
|
|
|
|
#include "llvm/Analysis/ConstantFolding.h"
|
2010-12-16 04:02:24 +08:00
|
|
|
#include "llvm/Analysis/ValueTracking.h"
|
2013-01-02 19:36:10 +08:00
|
|
|
#include "llvm/IR/Constants.h"
|
|
|
|
#include "llvm/IR/DataLayout.h"
|
|
|
|
#include "llvm/IR/Instructions.h"
|
|
|
|
#include "llvm/IR/IntrinsicInst.h"
|
2009-11-12 06:48:44 +08:00
|
|
|
#include "llvm/Support/CFG.h"
|
2010-08-06 06:59:19 +08:00
|
|
|
#include "llvm/Support/ConstantRange.h"
|
2009-11-12 09:22:16 +08:00
|
|
|
#include "llvm/Support/Debug.h"
|
2012-03-02 23:34:43 +08:00
|
|
|
#include "llvm/Support/PatternMatch.h"
|
2010-07-31 07:59:40 +08:00
|
|
|
#include "llvm/Support/ValueHandle.h"
|
2012-12-04 00:50:05 +08:00
|
|
|
#include "llvm/Support/raw_ostream.h"
|
|
|
|
#include "llvm/Target/TargetLibraryInfo.h"
|
2012-01-12 07:43:34 +08:00
|
|
|
#include <map>
|
2010-12-18 09:00:40 +08:00
|
|
|
#include <stack>
|
2009-11-11 08:22:30 +08:00
|
|
|
using namespace llvm;
|
2012-03-02 23:34:43 +08:00
|
|
|
using namespace PatternMatch;
|
2009-11-11 08:22:30 +08:00
|
|
|
|
|
|
|
char LazyValueInfo::ID = 0;
|
2011-12-02 09:26:24 +08:00
|
|
|
INITIALIZE_PASS_BEGIN(LazyValueInfo, "lazy-value-info",
|
|
|
|
"Lazy Value Information Analysis", false, true)
|
|
|
|
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
|
|
|
|
INITIALIZE_PASS_END(LazyValueInfo, "lazy-value-info",
|
2010-10-08 06:25:06 +08:00
|
|
|
"Lazy Value Information Analysis", false, true)
|
2009-11-11 08:22:30 +08:00
|
|
|
|
|
|
|
namespace llvm {
|
|
|
|
FunctionPass *createLazyValueInfoPass() { return new LazyValueInfo(); }
|
|
|
|
}
|
|
|
|
|
2009-11-11 10:08:33 +08:00
|
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// LVILatticeVal
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
|
|
|
|
/// LVILatticeVal - This is the information tracked by LazyValueInfo for each
|
|
|
|
/// value.
|
|
|
|
///
|
|
|
|
/// FIXME: This is basically just for bringup, this can be made a lot more rich
|
|
|
|
/// in the future.
|
|
|
|
///
|
|
|
|
namespace {
|
|
|
|
class LVILatticeVal {
|
|
|
|
enum LatticeValueTy {
|
2010-12-16 02:57:18 +08:00
|
|
|
/// undefined - This Value has no known value yet.
|
2009-11-11 10:08:33 +08:00
|
|
|
undefined,
|
2010-08-06 06:59:19 +08:00
|
|
|
|
2010-12-16 02:57:18 +08:00
|
|
|
/// constant - This Value has a specific constant value.
|
2009-11-11 10:08:33 +08:00
|
|
|
constant,
|
2010-12-16 02:57:18 +08:00
|
|
|
/// notconstant - This Value is known to not have the specified value.
|
2009-11-12 12:36:58 +08:00
|
|
|
notconstant,
|
2011-12-02 09:26:24 +08:00
|
|
|
|
2010-12-16 02:57:18 +08:00
|
|
|
/// constantrange - The Value falls within this range.
|
2010-08-06 06:59:19 +08:00
|
|
|
constantrange,
|
2011-12-02 09:26:24 +08:00
|
|
|
|
2010-12-16 02:57:18 +08:00
|
|
|
/// overdefined - This value is not known to be constant, and we know that
|
2009-11-11 10:08:33 +08:00
|
|
|
/// it has a value.
|
|
|
|
overdefined
|
|
|
|
};
|
|
|
|
|
|
|
|
/// Val: This stores the current lattice value along with the Constant* for
|
2009-11-12 12:36:58 +08:00
|
|
|
/// the constant if this is a 'constant' or 'notconstant' value.
|
2010-08-06 06:10:46 +08:00
|
|
|
LatticeValueTy Tag;
|
|
|
|
Constant *Val;
|
2010-08-06 06:59:19 +08:00
|
|
|
ConstantRange Range;
|
2009-11-11 10:08:33 +08:00
|
|
|
|
|
|
|
public:
|
2010-08-06 06:59:19 +08:00
|
|
|
LVILatticeVal() : Tag(undefined), Val(0), Range(1, true) {}
|
2009-11-11 10:08:33 +08:00
|
|
|
|
2009-11-12 06:48:44 +08:00
|
|
|
static LVILatticeVal get(Constant *C) {
|
|
|
|
LVILatticeVal Res;
|
2010-12-16 02:57:18 +08:00
|
|
|
if (!isa<UndefValue>(C))
|
2010-08-11 04:03:09 +08:00
|
|
|
Res.markConstant(C);
|
2009-11-12 06:48:44 +08:00
|
|
|
return Res;
|
|
|
|
}
|
2009-11-12 12:36:58 +08:00
|
|
|
static LVILatticeVal getNot(Constant *C) {
|
|
|
|
LVILatticeVal Res;
|
2010-12-16 02:57:18 +08:00
|
|
|
if (!isa<UndefValue>(C))
|
2010-08-11 04:03:09 +08:00
|
|
|
Res.markNotConstant(C);
|
2009-11-12 12:36:58 +08:00
|
|
|
return Res;
|
|
|
|
}
|
2010-08-11 07:20:01 +08:00
|
|
|
static LVILatticeVal getRange(ConstantRange CR) {
|
|
|
|
LVILatticeVal Res;
|
|
|
|
Res.markConstantRange(CR);
|
|
|
|
return Res;
|
|
|
|
}
|
2009-11-12 06:48:44 +08:00
|
|
|
|
2010-08-06 06:59:19 +08:00
|
|
|
bool isUndefined() const { return Tag == undefined; }
|
|
|
|
bool isConstant() const { return Tag == constant; }
|
|
|
|
bool isNotConstant() const { return Tag == notconstant; }
|
|
|
|
bool isConstantRange() const { return Tag == constantrange; }
|
|
|
|
bool isOverdefined() const { return Tag == overdefined; }
|
2009-11-11 10:08:33 +08:00
|
|
|
|
|
|
|
Constant *getConstant() const {
|
|
|
|
assert(isConstant() && "Cannot get the constant of a non-constant!");
|
2010-08-06 06:10:46 +08:00
|
|
|
return Val;
|
2009-11-11 10:08:33 +08:00
|
|
|
}
|
|
|
|
|
2009-11-12 12:36:58 +08:00
|
|
|
Constant *getNotConstant() const {
|
|
|
|
assert(isNotConstant() && "Cannot get the constant of a non-notconstant!");
|
2010-08-06 06:10:46 +08:00
|
|
|
return Val;
|
2009-11-11 10:08:33 +08:00
|
|
|
}
|
|
|
|
|
2010-08-06 06:59:19 +08:00
|
|
|
ConstantRange getConstantRange() const {
|
|
|
|
assert(isConstantRange() &&
|
|
|
|
"Cannot get the constant-range of a non-constant-range!");
|
|
|
|
return Range;
|
|
|
|
}
|
|
|
|
|
2009-11-11 10:08:33 +08:00
|
|
|
/// markOverdefined - Return true if this is a change in status.
|
|
|
|
bool markOverdefined() {
|
|
|
|
if (isOverdefined())
|
|
|
|
return false;
|
2010-08-06 06:10:46 +08:00
|
|
|
Tag = overdefined;
|
2009-11-11 10:08:33 +08:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
/// markConstant - Return true if this is a change in status.
|
|
|
|
bool markConstant(Constant *V) {
|
2010-12-16 02:57:18 +08:00
|
|
|
assert(V && "Marking constant with NULL");
|
|
|
|
if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
|
|
|
|
return markConstantRange(ConstantRange(CI->getValue()));
|
|
|
|
if (isa<UndefValue>(V))
|
2009-11-11 10:08:33 +08:00
|
|
|
return false;
|
2010-12-16 02:57:18 +08:00
|
|
|
|
|
|
|
assert((!isConstant() || getConstant() == V) &&
|
|
|
|
"Marking constant with different value");
|
2009-11-11 10:08:33 +08:00
|
|
|
assert(isUndefined());
|
2010-08-06 06:10:46 +08:00
|
|
|
Tag = constant;
|
|
|
|
Val = V;
|
2009-11-12 06:48:44 +08:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2009-11-12 12:36:58 +08:00
|
|
|
/// markNotConstant - Return true if this is a change in status.
|
|
|
|
bool markNotConstant(Constant *V) {
|
2010-12-16 02:57:18 +08:00
|
|
|
assert(V && "Marking constant with NULL");
|
|
|
|
if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
|
|
|
|
return markConstantRange(ConstantRange(CI->getValue()+1, CI->getValue()));
|
|
|
|
if (isa<UndefValue>(V))
|
2009-11-12 12:36:58 +08:00
|
|
|
return false;
|
|
|
|
|
2010-12-16 02:57:18 +08:00
|
|
|
assert((!isConstant() || getConstant() != V) &&
|
|
|
|
"Marking constant !constant with same value");
|
|
|
|
assert((!isNotConstant() || getNotConstant() == V) &&
|
|
|
|
"Marking !constant with different value");
|
|
|
|
assert(isUndefined() || isConstant());
|
2010-08-06 06:10:46 +08:00
|
|
|
Tag = notconstant;
|
|
|
|
Val = V;
|
2009-11-12 12:36:58 +08:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2010-08-06 06:59:19 +08:00
|
|
|
/// markConstantRange - Return true if this is a change in status.
|
|
|
|
bool markConstantRange(const ConstantRange NewR) {
|
|
|
|
if (isConstantRange()) {
|
|
|
|
if (NewR.isEmptySet())
|
|
|
|
return markOverdefined();
|
|
|
|
|
2012-06-28 09:16:18 +08:00
|
|
|
bool changed = Range != NewR;
|
2010-08-06 06:59:19 +08:00
|
|
|
Range = NewR;
|
|
|
|
return changed;
|
|
|
|
}
|
|
|
|
|
|
|
|
assert(isUndefined());
|
|
|
|
if (NewR.isEmptySet())
|
|
|
|
return markOverdefined();
|
|
|
|
|
|
|
|
Tag = constantrange;
|
|
|
|
Range = NewR;
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2009-11-12 06:48:44 +08:00
|
|
|
/// mergeIn - Merge the specified lattice value into this one, updating this
|
|
|
|
/// one and returning true if anything changed.
|
|
|
|
bool mergeIn(const LVILatticeVal &RHS) {
|
|
|
|
if (RHS.isUndefined() || isOverdefined()) return false;
|
|
|
|
if (RHS.isOverdefined()) return markOverdefined();
|
|
|
|
|
2010-12-16 02:57:18 +08:00
|
|
|
if (isUndefined()) {
|
|
|
|
Tag = RHS.Tag;
|
|
|
|
Val = RHS.Val;
|
|
|
|
Range = RHS.Range;
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (isConstant()) {
|
|
|
|
if (RHS.isConstant()) {
|
|
|
|
if (Val == RHS.Val)
|
|
|
|
return false;
|
2010-08-31 01:03:45 +08:00
|
|
|
return markOverdefined();
|
2009-11-12 12:57:13 +08:00
|
|
|
}
|
2010-12-16 02:57:18 +08:00
|
|
|
|
|
|
|
if (RHS.isNotConstant()) {
|
|
|
|
if (Val == RHS.Val)
|
2010-08-06 06:59:19 +08:00
|
|
|
return markOverdefined();
|
2010-12-16 02:57:18 +08:00
|
|
|
|
|
|
|
// Unless we can prove that the two Constants are different, we must
|
|
|
|
// move to overdefined.
|
2012-10-09 00:38:25 +08:00
|
|
|
// FIXME: use DataLayout/TargetLibraryInfo for smarter constant folding.
|
2010-12-16 02:57:18 +08:00
|
|
|
if (ConstantInt *Res = dyn_cast<ConstantInt>(
|
|
|
|
ConstantFoldCompareInstOperands(CmpInst::ICMP_NE,
|
|
|
|
getConstant(),
|
|
|
|
RHS.getNotConstant())))
|
|
|
|
if (Res->isOne())
|
|
|
|
return markNotConstant(RHS.getNotConstant());
|
|
|
|
|
2010-08-24 15:55:44 +08:00
|
|
|
return markOverdefined();
|
2010-08-06 06:59:19 +08:00
|
|
|
}
|
2010-12-16 02:57:18 +08:00
|
|
|
|
|
|
|
// RHS is a ConstantRange, LHS is a non-integer Constant.
|
|
|
|
|
|
|
|
// FIXME: consider the case where RHS is a range [1, 0) and LHS is
|
|
|
|
// a function. The correct result is to pick up RHS.
|
|
|
|
|
2010-09-17 02:28:33 +08:00
|
|
|
return markOverdefined();
|
|
|
|
}
|
2010-12-16 02:57:18 +08:00
|
|
|
|
|
|
|
if (isNotConstant()) {
|
|
|
|
if (RHS.isConstant()) {
|
|
|
|
if (Val == RHS.Val)
|
|
|
|
return markOverdefined();
|
|
|
|
|
|
|
|
// Unless we can prove that the two Constants are different, we must
|
|
|
|
// move to overdefined.
|
2012-10-09 00:38:25 +08:00
|
|
|
// FIXME: use DataLayout/TargetLibraryInfo for smarter constant folding.
|
2010-12-16 02:57:18 +08:00
|
|
|
if (ConstantInt *Res = dyn_cast<ConstantInt>(
|
|
|
|
ConstantFoldCompareInstOperands(CmpInst::ICMP_NE,
|
|
|
|
getNotConstant(),
|
|
|
|
RHS.getConstant())))
|
|
|
|
if (Res->isOne())
|
|
|
|
return false;
|
|
|
|
|
2009-11-12 12:57:13 +08:00
|
|
|
return markOverdefined();
|
2010-12-16 02:57:18 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
if (RHS.isNotConstant()) {
|
|
|
|
if (Val == RHS.Val)
|
|
|
|
return false;
|
|
|
|
return markOverdefined();
|
|
|
|
}
|
|
|
|
|
|
|
|
return markOverdefined();
|
2009-11-12 12:57:13 +08:00
|
|
|
}
|
|
|
|
|
2010-12-16 02:57:18 +08:00
|
|
|
assert(isConstantRange() && "New LVILattice type?");
|
|
|
|
if (!RHS.isConstantRange())
|
2009-11-12 06:48:44 +08:00
|
|
|
return markOverdefined();
|
2010-12-16 02:57:18 +08:00
|
|
|
|
|
|
|
ConstantRange NewR = Range.unionWith(RHS.getConstantRange());
|
|
|
|
if (NewR.isFullSet())
|
|
|
|
return markOverdefined();
|
|
|
|
return markConstantRange(NewR);
|
2009-11-11 10:08:33 +08:00
|
|
|
}
|
|
|
|
};
|
|
|
|
|
|
|
|
} // end anonymous namespace.
|
|
|
|
|
2009-11-12 06:48:44 +08:00
|
|
|
namespace llvm {
|
2011-04-19 02:49:44 +08:00
|
|
|
raw_ostream &operator<<(raw_ostream &OS, const LVILatticeVal &Val)
|
|
|
|
LLVM_ATTRIBUTE_USED;
|
2009-11-12 06:48:44 +08:00
|
|
|
raw_ostream &operator<<(raw_ostream &OS, const LVILatticeVal &Val) {
|
|
|
|
if (Val.isUndefined())
|
|
|
|
return OS << "undefined";
|
|
|
|
if (Val.isOverdefined())
|
|
|
|
return OS << "overdefined";
|
2009-11-12 12:36:58 +08:00
|
|
|
|
|
|
|
if (Val.isNotConstant())
|
|
|
|
return OS << "notconstant<" << *Val.getNotConstant() << '>';
|
2010-08-10 04:50:46 +08:00
|
|
|
else if (Val.isConstantRange())
|
|
|
|
return OS << "constantrange<" << Val.getConstantRange().getLower() << ", "
|
|
|
|
<< Val.getConstantRange().getUpper() << '>';
|
2009-11-12 06:48:44 +08:00
|
|
|
return OS << "constant<" << *Val.getConstant() << '>';
|
|
|
|
}
|
|
|
|
}
|
2009-11-11 10:08:33 +08:00
|
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
2009-11-16 03:59:49 +08:00
|
|
|
// LazyValueInfoCache Decl
|
2009-11-11 10:08:33 +08:00
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
|
2009-11-16 03:59:49 +08:00
|
|
|
namespace {
|
2012-10-26 12:43:47 +08:00
|
|
|
/// LVIValueHandle - A callback value handle updates the cache when
|
2011-01-06 05:15:29 +08:00
|
|
|
/// values are erased.
|
|
|
|
class LazyValueInfoCache;
|
|
|
|
struct LVIValueHandle : public CallbackVH {
|
|
|
|
LazyValueInfoCache *Parent;
|
|
|
|
|
|
|
|
LVIValueHandle(Value *V, LazyValueInfoCache *P)
|
|
|
|
: CallbackVH(V), Parent(P) { }
|
|
|
|
|
|
|
|
void deleted();
|
|
|
|
void allUsesReplacedWith(Value *V) {
|
|
|
|
deleted();
|
|
|
|
}
|
|
|
|
};
|
|
|
|
}
|
|
|
|
|
|
|
|
namespace {
|
2009-11-16 03:59:49 +08:00
|
|
|
/// LazyValueInfoCache - This is the cache kept by LazyValueInfo which
|
|
|
|
/// maintains information about queries across the clients' queries.
|
|
|
|
class LazyValueInfoCache {
|
|
|
|
/// ValueCacheEntryTy - This is all of the cached block information for
|
|
|
|
/// exactly one Value*. The entries are sorted by the BasicBlock* of the
|
|
|
|
/// entries, allowing us to do a lookup with a binary search.
|
2012-01-12 07:43:34 +08:00
|
|
|
typedef std::map<AssertingVH<BasicBlock>, LVILatticeVal> ValueCacheEntryTy;
|
2009-11-11 08:22:30 +08:00
|
|
|
|
2011-01-06 07:26:22 +08:00
|
|
|
/// ValueCache - This is all of the cached information for all values,
|
|
|
|
/// mapped from Value* to key information.
|
2012-01-12 09:41:03 +08:00
|
|
|
std::map<LVIValueHandle, ValueCacheEntryTy> ValueCache;
|
2011-01-06 07:26:22 +08:00
|
|
|
|
|
|
|
/// OverDefinedCache - This tracks, on a per-block basis, the set of
|
|
|
|
/// values that are over-defined at the end of that block. This is required
|
|
|
|
/// for cache updating.
|
|
|
|
typedef std::pair<AssertingVH<BasicBlock>, Value*> OverDefinedPairTy;
|
|
|
|
DenseSet<OverDefinedPairTy> OverDefinedCache;
|
2011-12-03 23:16:45 +08:00
|
|
|
|
|
|
|
/// SeenBlocks - Keep track of all blocks that we have ever seen, so we
|
|
|
|
/// don't spend time removing unused blocks from our caches.
|
|
|
|
DenseSet<AssertingVH<BasicBlock> > SeenBlocks;
|
|
|
|
|
2011-01-06 07:26:22 +08:00
|
|
|
/// BlockValueStack - This stack holds the state of the value solver
|
|
|
|
/// during a query. It basically emulates the callstack of the naive
|
|
|
|
/// recursive value lookup process.
|
|
|
|
std::stack<std::pair<BasicBlock*, Value*> > BlockValueStack;
|
|
|
|
|
2011-01-06 05:15:29 +08:00
|
|
|
friend struct LVIValueHandle;
|
2010-12-21 03:33:41 +08:00
|
|
|
|
|
|
|
/// OverDefinedCacheUpdater - A helper object that ensures that the
|
|
|
|
/// OverDefinedCache is updated whenever solveBlockValue returns.
|
|
|
|
struct OverDefinedCacheUpdater {
|
|
|
|
LazyValueInfoCache *Parent;
|
|
|
|
Value *Val;
|
|
|
|
BasicBlock *BB;
|
|
|
|
LVILatticeVal &BBLV;
|
|
|
|
|
|
|
|
OverDefinedCacheUpdater(Value *V, BasicBlock *B, LVILatticeVal &LV,
|
|
|
|
LazyValueInfoCache *P)
|
|
|
|
: Parent(P), Val(V), BB(B), BBLV(LV) { }
|
|
|
|
|
|
|
|
bool markResult(bool changed) {
|
|
|
|
if (changed && BBLV.isOverdefined())
|
|
|
|
Parent->OverDefinedCache.insert(std::make_pair(BB, Val));
|
|
|
|
return changed;
|
|
|
|
}
|
|
|
|
};
|
2010-07-27 02:48:03 +08:00
|
|
|
|
2011-01-06 07:26:22 +08:00
|
|
|
|
2010-07-31 07:59:40 +08:00
|
|
|
|
2010-12-09 14:14:58 +08:00
|
|
|
LVILatticeVal getBlockValue(Value *Val, BasicBlock *BB);
|
2010-12-18 09:00:40 +08:00
|
|
|
bool getEdgeValue(Value *V, BasicBlock *F, BasicBlock *T,
|
|
|
|
LVILatticeVal &Result);
|
|
|
|
bool hasBlockValue(Value *Val, BasicBlock *BB);
|
|
|
|
|
|
|
|
// These methods process one work item and may add more. A false value
|
|
|
|
// returned means that the work item was not completely processed and must
|
|
|
|
// be revisited after going through the new items.
|
|
|
|
bool solveBlockValue(Value *Val, BasicBlock *BB);
|
2010-12-21 02:18:16 +08:00
|
|
|
bool solveBlockValueNonLocal(LVILatticeVal &BBLV,
|
|
|
|
Value *Val, BasicBlock *BB);
|
|
|
|
bool solveBlockValuePHINode(LVILatticeVal &BBLV,
|
|
|
|
PHINode *PN, BasicBlock *BB);
|
|
|
|
bool solveBlockValueConstantRange(LVILatticeVal &BBLV,
|
|
|
|
Instruction *BBI, BasicBlock *BB);
|
2010-12-18 09:00:40 +08:00
|
|
|
|
|
|
|
void solve();
|
2010-12-09 14:14:58 +08:00
|
|
|
|
2010-12-16 02:57:18 +08:00
|
|
|
ValueCacheEntryTy &lookup(Value *V) {
|
2010-12-09 14:14:58 +08:00
|
|
|
return ValueCache[LVIValueHandle(V, this)];
|
|
|
|
}
|
2010-12-18 09:00:40 +08:00
|
|
|
|
2009-11-16 03:59:49 +08:00
|
|
|
public:
|
|
|
|
/// getValueInBlock - This is the query interface to determine the lattice
|
|
|
|
/// value for the specified Value* at the end of the specified block.
|
|
|
|
LVILatticeVal getValueInBlock(Value *V, BasicBlock *BB);
|
2009-11-11 10:08:33 +08:00
|
|
|
|
2009-11-16 03:59:49 +08:00
|
|
|
/// getValueOnEdge - This is the query interface to determine the lattice
|
|
|
|
/// value for the specified Value* that is true on the specified edge.
|
|
|
|
LVILatticeVal getValueOnEdge(Value *V, BasicBlock *FromBB,BasicBlock *ToBB);
|
2010-07-27 02:48:03 +08:00
|
|
|
|
|
|
|
/// threadEdge - This is the update interface to inform the cache that an
|
|
|
|
/// edge from PredBB to OldSucc has been threaded to be from PredBB to
|
|
|
|
/// NewSucc.
|
|
|
|
void threadEdge(BasicBlock *PredBB,BasicBlock *OldSucc,BasicBlock *NewSucc);
|
2010-08-19 02:39:01 +08:00
|
|
|
|
|
|
|
/// eraseBlock - This is part of the update interface to inform the cache
|
|
|
|
/// that a block has been deleted.
|
|
|
|
void eraseBlock(BasicBlock *BB);
|
|
|
|
|
|
|
|
/// clear - Empty the cache.
|
|
|
|
void clear() {
|
2011-12-03 23:19:55 +08:00
|
|
|
SeenBlocks.clear();
|
2010-08-19 02:39:01 +08:00
|
|
|
ValueCache.clear();
|
|
|
|
OverDefinedCache.clear();
|
|
|
|
}
|
2009-11-16 03:59:49 +08:00
|
|
|
};
|
|
|
|
} // end anonymous namespace
|
2009-11-12 06:48:44 +08:00
|
|
|
|
2011-01-06 05:15:29 +08:00
|
|
|
void LVIValueHandle::deleted() {
|
|
|
|
typedef std::pair<AssertingVH<BasicBlock>, Value*> OverDefinedPairTy;
|
|
|
|
|
|
|
|
SmallVector<OverDefinedPairTy, 4> ToErase;
|
|
|
|
for (DenseSet<OverDefinedPairTy>::iterator
|
2010-07-31 07:59:40 +08:00
|
|
|
I = Parent->OverDefinedCache.begin(),
|
|
|
|
E = Parent->OverDefinedCache.end();
|
2011-01-06 05:15:29 +08:00
|
|
|
I != E; ++I) {
|
|
|
|
if (I->second == getValPtr())
|
|
|
|
ToErase.push_back(*I);
|
2010-07-31 07:59:40 +08:00
|
|
|
}
|
2010-08-12 06:36:04 +08:00
|
|
|
|
2011-01-06 05:15:29 +08:00
|
|
|
for (SmallVector<OverDefinedPairTy, 4>::iterator I = ToErase.begin(),
|
|
|
|
E = ToErase.end(); I != E; ++I)
|
|
|
|
Parent->OverDefinedCache.erase(*I);
|
|
|
|
|
2010-08-12 06:36:04 +08:00
|
|
|
// This erasure deallocates *this, so it MUST happen after we're done
|
|
|
|
// using any and all members of *this.
|
|
|
|
Parent->ValueCache.erase(*this);
|
2010-07-31 07:59:40 +08:00
|
|
|
}
|
|
|
|
|
2010-08-19 02:39:01 +08:00
|
|
|
void LazyValueInfoCache::eraseBlock(BasicBlock *BB) {
|
2011-12-03 23:16:45 +08:00
|
|
|
// Shortcut if we have never seen this block.
|
|
|
|
DenseSet<AssertingVH<BasicBlock> >::iterator I = SeenBlocks.find(BB);
|
|
|
|
if (I == SeenBlocks.end())
|
|
|
|
return;
|
|
|
|
SeenBlocks.erase(I);
|
|
|
|
|
2011-01-06 05:15:29 +08:00
|
|
|
SmallVector<OverDefinedPairTy, 4> ToErase;
|
|
|
|
for (DenseSet<OverDefinedPairTy>::iterator I = OverDefinedCache.begin(),
|
|
|
|
E = OverDefinedCache.end(); I != E; ++I) {
|
|
|
|
if (I->first == BB)
|
|
|
|
ToErase.push_back(*I);
|
2010-08-19 02:39:01 +08:00
|
|
|
}
|
2011-01-06 05:15:29 +08:00
|
|
|
|
|
|
|
for (SmallVector<OverDefinedPairTy, 4>::iterator I = ToErase.begin(),
|
|
|
|
E = ToErase.end(); I != E; ++I)
|
|
|
|
OverDefinedCache.erase(*I);
|
2010-08-19 02:39:01 +08:00
|
|
|
|
2012-01-12 09:41:03 +08:00
|
|
|
for (std::map<LVIValueHandle, ValueCacheEntryTy>::iterator
|
2010-08-19 02:39:01 +08:00
|
|
|
I = ValueCache.begin(), E = ValueCache.end(); I != E; ++I)
|
|
|
|
I->second.erase(BB);
|
|
|
|
}
|
2010-07-31 07:59:40 +08:00
|
|
|
|
2010-12-18 09:00:40 +08:00
|
|
|
void LazyValueInfoCache::solve() {
|
2011-01-06 07:26:22 +08:00
|
|
|
while (!BlockValueStack.empty()) {
|
|
|
|
std::pair<BasicBlock*, Value*> &e = BlockValueStack.top();
|
2012-06-28 09:16:18 +08:00
|
|
|
if (solveBlockValue(e.second, e.first)) {
|
|
|
|
assert(BlockValueStack.top() == e);
|
2011-01-06 07:26:22 +08:00
|
|
|
BlockValueStack.pop();
|
2012-06-28 09:16:18 +08:00
|
|
|
}
|
2010-12-18 09:00:40 +08:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
bool LazyValueInfoCache::hasBlockValue(Value *Val, BasicBlock *BB) {
|
|
|
|
// If already a constant, there is nothing to compute.
|
|
|
|
if (isa<Constant>(Val))
|
|
|
|
return true;
|
|
|
|
|
2011-01-06 05:15:29 +08:00
|
|
|
LVIValueHandle ValHandle(Val, this);
|
2012-08-22 23:37:57 +08:00
|
|
|
std::map<LVIValueHandle, ValueCacheEntryTy>::iterator I =
|
|
|
|
ValueCache.find(ValHandle);
|
|
|
|
if (I == ValueCache.end()) return false;
|
|
|
|
return I->second.count(BB);
|
2010-12-18 09:00:40 +08:00
|
|
|
}
|
|
|
|
|
2010-12-09 14:14:58 +08:00
|
|
|
LVILatticeVal LazyValueInfoCache::getBlockValue(Value *Val, BasicBlock *BB) {
|
2010-12-18 09:00:40 +08:00
|
|
|
// If already a constant, there is nothing to compute.
|
|
|
|
if (Constant *VC = dyn_cast<Constant>(Val))
|
|
|
|
return LVILatticeVal::get(VC);
|
|
|
|
|
2011-12-03 23:16:45 +08:00
|
|
|
SeenBlocks.insert(BB);
|
2010-12-18 09:00:40 +08:00
|
|
|
return lookup(Val)[BB];
|
|
|
|
}
|
|
|
|
|
|
|
|
bool LazyValueInfoCache::solveBlockValue(Value *Val, BasicBlock *BB) {
|
|
|
|
if (isa<Constant>(Val))
|
|
|
|
return true;
|
|
|
|
|
2010-12-09 14:14:58 +08:00
|
|
|
ValueCacheEntryTy &Cache = lookup(Val);
|
2011-12-03 23:16:45 +08:00
|
|
|
SeenBlocks.insert(BB);
|
2010-12-09 14:14:58 +08:00
|
|
|
LVILatticeVal &BBLV = Cache[BB];
|
2010-12-21 03:33:41 +08:00
|
|
|
|
|
|
|
// OverDefinedCacheUpdater is a helper object that will update
|
|
|
|
// the OverDefinedCache for us when this method exits. Make sure to
|
|
|
|
// call markResult on it as we exist, passing a bool to indicate if the
|
|
|
|
// cache needs updating, i.e. if we have solve a new value or not.
|
|
|
|
OverDefinedCacheUpdater ODCacheUpdater(Val, BB, BBLV, this);
|
2010-12-18 09:00:40 +08:00
|
|
|
|
2009-11-12 06:48:44 +08:00
|
|
|
// If we've already computed this block's value, return it.
|
2009-11-16 04:00:52 +08:00
|
|
|
if (!BBLV.isUndefined()) {
|
2009-12-24 04:43:58 +08:00
|
|
|
DEBUG(dbgs() << " reuse BB '" << BB->getName() << "' val=" << BBLV <<'\n');
|
2010-12-21 03:33:41 +08:00
|
|
|
|
|
|
|
// Since we're reusing a cached value here, we don't need to update the
|
|
|
|
// OverDefinedCahce. The cache will have been properly updated
|
|
|
|
// whenever the cached value was inserted.
|
|
|
|
ODCacheUpdater.markResult(false);
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
2009-11-16 04:00:52 +08:00
|
|
|
}
|
|
|
|
|
2009-11-12 06:48:44 +08:00
|
|
|
// Otherwise, this is the first time we're seeing this block. Reset the
|
|
|
|
// lattice value to overdefined, so that cycles will terminate and be
|
|
|
|
// conservatively correct.
|
|
|
|
BBLV.markOverdefined();
|
|
|
|
|
2009-11-16 03:59:49 +08:00
|
|
|
Instruction *BBI = dyn_cast<Instruction>(Val);
|
2009-11-12 06:48:44 +08:00
|
|
|
if (BBI == 0 || BBI->getParent() != BB) {
|
2010-12-21 03:33:41 +08:00
|
|
|
return ODCacheUpdater.markResult(solveBlockValueNonLocal(BBLV, Val, BB));
|
2009-11-12 06:48:44 +08:00
|
|
|
}
|
2010-12-18 09:00:40 +08:00
|
|
|
|
2009-11-12 06:48:44 +08:00
|
|
|
if (PHINode *PN = dyn_cast<PHINode>(BBI)) {
|
2010-12-21 03:33:41 +08:00
|
|
|
return ODCacheUpdater.markResult(solveBlockValuePHINode(BBLV, PN, BB));
|
2009-11-12 06:48:44 +08:00
|
|
|
}
|
2009-11-16 04:00:52 +08:00
|
|
|
|
2011-01-15 17:16:12 +08:00
|
|
|
if (AllocaInst *AI = dyn_cast<AllocaInst>(BBI)) {
|
|
|
|
BBLV = LVILatticeVal::getNot(ConstantPointerNull::get(AI->getType()));
|
|
|
|
return ODCacheUpdater.markResult(true);
|
|
|
|
}
|
|
|
|
|
2010-08-19 05:11:37 +08:00
|
|
|
// We can only analyze the definitions of certain classes of instructions
|
|
|
|
// (integral binops and casts at the moment), so bail if this isn't one.
|
2009-11-16 03:59:49 +08:00
|
|
|
LVILatticeVal Result;
|
2010-08-19 05:11:37 +08:00
|
|
|
if ((!isa<BinaryOperator>(BBI) && !isa<CastInst>(BBI)) ||
|
|
|
|
!BBI->getType()->isIntegerTy()) {
|
|
|
|
DEBUG(dbgs() << " compute BB '" << BB->getName()
|
|
|
|
<< "' - overdefined because inst def found.\n");
|
2010-12-21 02:18:16 +08:00
|
|
|
BBLV.markOverdefined();
|
2010-12-21 03:33:41 +08:00
|
|
|
return ODCacheUpdater.markResult(true);
|
2010-08-19 05:11:37 +08:00
|
|
|
}
|
2010-12-18 09:00:40 +08:00
|
|
|
|
2010-08-19 05:11:37 +08:00
|
|
|
// FIXME: We're currently limited to binops with a constant RHS. This should
|
|
|
|
// be improved.
|
|
|
|
BinaryOperator *BO = dyn_cast<BinaryOperator>(BBI);
|
|
|
|
if (BO && !isa<ConstantInt>(BO->getOperand(1))) {
|
|
|
|
DEBUG(dbgs() << " compute BB '" << BB->getName()
|
|
|
|
<< "' - overdefined because inst def found.\n");
|
|
|
|
|
2010-12-21 02:18:16 +08:00
|
|
|
BBLV.markOverdefined();
|
2010-12-21 03:33:41 +08:00
|
|
|
return ODCacheUpdater.markResult(true);
|
2010-12-18 09:00:40 +08:00
|
|
|
}
|
|
|
|
|
2010-12-21 03:33:41 +08:00
|
|
|
return ODCacheUpdater.markResult(solveBlockValueConstantRange(BBLV, BBI, BB));
|
2010-12-18 09:00:40 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
static bool InstructionDereferencesPointer(Instruction *I, Value *Ptr) {
|
|
|
|
if (LoadInst *L = dyn_cast<LoadInst>(I)) {
|
|
|
|
return L->getPointerAddressSpace() == 0 &&
|
2012-10-26 12:43:47 +08:00
|
|
|
GetUnderlyingObject(L->getPointerOperand()) == Ptr;
|
2010-12-18 09:00:40 +08:00
|
|
|
}
|
|
|
|
if (StoreInst *S = dyn_cast<StoreInst>(I)) {
|
|
|
|
return S->getPointerAddressSpace() == 0 &&
|
2012-10-26 12:43:47 +08:00
|
|
|
GetUnderlyingObject(S->getPointerOperand()) == Ptr;
|
2010-12-18 09:00:40 +08:00
|
|
|
}
|
2011-01-15 17:16:12 +08:00
|
|
|
if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(I)) {
|
|
|
|
if (MI->isVolatile()) return false;
|
|
|
|
|
|
|
|
// FIXME: check whether it has a valuerange that excludes zero?
|
|
|
|
ConstantInt *Len = dyn_cast<ConstantInt>(MI->getLength());
|
|
|
|
if (!Len || Len->isZero()) return false;
|
|
|
|
|
2011-06-01 04:40:16 +08:00
|
|
|
if (MI->getDestAddressSpace() == 0)
|
2012-10-26 12:43:47 +08:00
|
|
|
if (GetUnderlyingObject(MI->getRawDest()) == Ptr)
|
2011-06-01 04:40:16 +08:00
|
|
|
return true;
|
2011-01-15 17:16:12 +08:00
|
|
|
if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI))
|
2011-06-01 04:40:16 +08:00
|
|
|
if (MTI->getSourceAddressSpace() == 0)
|
2012-10-26 12:43:47 +08:00
|
|
|
if (GetUnderlyingObject(MTI->getRawSource()) == Ptr)
|
2011-06-01 04:40:16 +08:00
|
|
|
return true;
|
2011-01-15 17:16:12 +08:00
|
|
|
}
|
2010-12-18 09:00:40 +08:00
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
2010-12-21 02:18:16 +08:00
|
|
|
bool LazyValueInfoCache::solveBlockValueNonLocal(LVILatticeVal &BBLV,
|
|
|
|
Value *Val, BasicBlock *BB) {
|
2010-12-18 09:00:40 +08:00
|
|
|
LVILatticeVal Result; // Start Undefined.
|
|
|
|
|
|
|
|
// If this is a pointer, and there's a load from that pointer in this BB,
|
|
|
|
// then we know that the pointer can't be NULL.
|
|
|
|
bool NotNull = false;
|
|
|
|
if (Val->getType()->isPointerTy()) {
|
2012-10-26 12:43:47 +08:00
|
|
|
if (isKnownNonNull(Val)) {
|
2011-01-15 17:16:12 +08:00
|
|
|
NotNull = true;
|
|
|
|
} else {
|
2012-10-26 12:43:47 +08:00
|
|
|
Value *UnderlyingVal = GetUnderlyingObject(Val);
|
|
|
|
// If 'GetUnderlyingObject' didn't converge, skip it. It won't converge
|
|
|
|
// inside InstructionDereferencesPointer either.
|
|
|
|
if (UnderlyingVal == GetUnderlyingObject(UnderlyingVal, NULL, 1)) {
|
|
|
|
for (BasicBlock::iterator BI = BB->begin(), BE = BB->end();
|
|
|
|
BI != BE; ++BI) {
|
|
|
|
if (InstructionDereferencesPointer(BI, UnderlyingVal)) {
|
|
|
|
NotNull = true;
|
|
|
|
break;
|
|
|
|
}
|
2011-01-15 17:16:12 +08:00
|
|
|
}
|
2010-12-18 09:00:40 +08:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
// If this is the entry block, we must be asking about an argument. The
|
|
|
|
// value is overdefined.
|
|
|
|
if (BB == &BB->getParent()->getEntryBlock()) {
|
|
|
|
assert(isa<Argument>(Val) && "Unknown live-in to the entry block");
|
|
|
|
if (NotNull) {
|
2011-07-18 12:54:35 +08:00
|
|
|
PointerType *PTy = cast<PointerType>(Val->getType());
|
2010-12-18 09:00:40 +08:00
|
|
|
Result = LVILatticeVal::getNot(ConstantPointerNull::get(PTy));
|
|
|
|
} else {
|
|
|
|
Result.markOverdefined();
|
|
|
|
}
|
2010-12-21 02:18:16 +08:00
|
|
|
BBLV = Result;
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
// Loop over all of our predecessors, merging what we know from them into
|
|
|
|
// result.
|
|
|
|
bool EdgesMissing = false;
|
|
|
|
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) {
|
|
|
|
LVILatticeVal EdgeResult;
|
|
|
|
EdgesMissing |= !getEdgeValue(Val, *PI, BB, EdgeResult);
|
|
|
|
if (EdgesMissing)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
Result.mergeIn(EdgeResult);
|
|
|
|
|
|
|
|
// If we hit overdefined, exit early. The BlockVals entry is already set
|
|
|
|
// to overdefined.
|
|
|
|
if (Result.isOverdefined()) {
|
|
|
|
DEBUG(dbgs() << " compute BB '" << BB->getName()
|
|
|
|
<< "' - overdefined because of pred.\n");
|
|
|
|
// If we previously determined that this is a pointer that can't be null
|
|
|
|
// then return that rather than giving up entirely.
|
|
|
|
if (NotNull) {
|
2011-07-18 12:54:35 +08:00
|
|
|
PointerType *PTy = cast<PointerType>(Val->getType());
|
2010-12-18 09:00:40 +08:00
|
|
|
Result = LVILatticeVal::getNot(ConstantPointerNull::get(PTy));
|
|
|
|
}
|
2010-12-21 02:18:16 +08:00
|
|
|
|
|
|
|
BBLV = Result;
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if (EdgesMissing)
|
|
|
|
return false;
|
|
|
|
|
|
|
|
// Return the merged value, which is more precise than 'overdefined'.
|
|
|
|
assert(!Result.isOverdefined());
|
2010-12-21 02:18:16 +08:00
|
|
|
BBLV = Result;
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2010-12-21 02:18:16 +08:00
|
|
|
bool LazyValueInfoCache::solveBlockValuePHINode(LVILatticeVal &BBLV,
|
|
|
|
PHINode *PN, BasicBlock *BB) {
|
2010-12-18 09:00:40 +08:00
|
|
|
LVILatticeVal Result; // Start Undefined.
|
|
|
|
|
|
|
|
// Loop over all of our predecessors, merging what we know from them into
|
|
|
|
// result.
|
|
|
|
bool EdgesMissing = false;
|
|
|
|
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
|
|
|
|
BasicBlock *PhiBB = PN->getIncomingBlock(i);
|
|
|
|
Value *PhiVal = PN->getIncomingValue(i);
|
|
|
|
LVILatticeVal EdgeResult;
|
|
|
|
EdgesMissing |= !getEdgeValue(PhiVal, PhiBB, BB, EdgeResult);
|
|
|
|
if (EdgesMissing)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
Result.mergeIn(EdgeResult);
|
|
|
|
|
|
|
|
// If we hit overdefined, exit early. The BlockVals entry is already set
|
|
|
|
// to overdefined.
|
|
|
|
if (Result.isOverdefined()) {
|
|
|
|
DEBUG(dbgs() << " compute BB '" << BB->getName()
|
|
|
|
<< "' - overdefined because of pred.\n");
|
2010-12-21 02:18:16 +08:00
|
|
|
|
|
|
|
BBLV = Result;
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if (EdgesMissing)
|
|
|
|
return false;
|
2010-08-19 05:11:37 +08:00
|
|
|
|
2010-12-18 09:00:40 +08:00
|
|
|
// Return the merged value, which is more precise than 'overdefined'.
|
|
|
|
assert(!Result.isOverdefined() && "Possible PHI in entry block?");
|
2010-12-21 02:18:16 +08:00
|
|
|
BBLV = Result;
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2010-12-21 02:18:16 +08:00
|
|
|
bool LazyValueInfoCache::solveBlockValueConstantRange(LVILatticeVal &BBLV,
|
|
|
|
Instruction *BBI,
|
2010-12-18 09:00:40 +08:00
|
|
|
BasicBlock *BB) {
|
2010-08-19 05:11:37 +08:00
|
|
|
// Figure out the range of the LHS. If that fails, bail.
|
2010-12-18 09:00:40 +08:00
|
|
|
if (!hasBlockValue(BBI->getOperand(0), BB)) {
|
2011-01-06 07:26:22 +08:00
|
|
|
BlockValueStack.push(std::make_pair(BB, BBI->getOperand(0)));
|
2010-12-18 09:00:40 +08:00
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
LVILatticeVal LHSVal = getBlockValue(BBI->getOperand(0), BB);
|
2010-08-19 05:11:37 +08:00
|
|
|
if (!LHSVal.isConstantRange()) {
|
2010-12-21 02:18:16 +08:00
|
|
|
BBLV.markOverdefined();
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
2010-08-19 05:11:37 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
ConstantRange LHSRange = LHSVal.getConstantRange();
|
|
|
|
ConstantRange RHSRange(1);
|
2011-07-18 12:54:35 +08:00
|
|
|
IntegerType *ResultTy = cast<IntegerType>(BBI->getType());
|
2010-08-19 05:11:37 +08:00
|
|
|
if (isa<BinaryOperator>(BBI)) {
|
2010-12-18 09:00:40 +08:00
|
|
|
if (ConstantInt *RHS = dyn_cast<ConstantInt>(BBI->getOperand(1))) {
|
|
|
|
RHSRange = ConstantRange(RHS->getValue());
|
|
|
|
} else {
|
2010-12-21 02:18:16 +08:00
|
|
|
BBLV.markOverdefined();
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
2010-08-24 15:55:44 +08:00
|
|
|
}
|
2010-08-19 05:11:37 +08:00
|
|
|
}
|
2010-12-18 09:00:40 +08:00
|
|
|
|
2010-08-19 05:11:37 +08:00
|
|
|
// NOTE: We're currently limited by the set of operations that ConstantRange
|
|
|
|
// can evaluate symbolically. Enhancing that set will allows us to analyze
|
|
|
|
// more definitions.
|
2010-12-21 02:18:16 +08:00
|
|
|
LVILatticeVal Result;
|
2010-08-19 05:11:37 +08:00
|
|
|
switch (BBI->getOpcode()) {
|
|
|
|
case Instruction::Add:
|
|
|
|
Result.markConstantRange(LHSRange.add(RHSRange));
|
|
|
|
break;
|
|
|
|
case Instruction::Sub:
|
|
|
|
Result.markConstantRange(LHSRange.sub(RHSRange));
|
|
|
|
break;
|
|
|
|
case Instruction::Mul:
|
|
|
|
Result.markConstantRange(LHSRange.multiply(RHSRange));
|
|
|
|
break;
|
|
|
|
case Instruction::UDiv:
|
|
|
|
Result.markConstantRange(LHSRange.udiv(RHSRange));
|
|
|
|
break;
|
|
|
|
case Instruction::Shl:
|
|
|
|
Result.markConstantRange(LHSRange.shl(RHSRange));
|
|
|
|
break;
|
|
|
|
case Instruction::LShr:
|
|
|
|
Result.markConstantRange(LHSRange.lshr(RHSRange));
|
|
|
|
break;
|
|
|
|
case Instruction::Trunc:
|
|
|
|
Result.markConstantRange(LHSRange.truncate(ResultTy->getBitWidth()));
|
|
|
|
break;
|
|
|
|
case Instruction::SExt:
|
|
|
|
Result.markConstantRange(LHSRange.signExtend(ResultTy->getBitWidth()));
|
|
|
|
break;
|
|
|
|
case Instruction::ZExt:
|
|
|
|
Result.markConstantRange(LHSRange.zeroExtend(ResultTy->getBitWidth()));
|
|
|
|
break;
|
|
|
|
case Instruction::BitCast:
|
|
|
|
Result.markConstantRange(LHSRange);
|
|
|
|
break;
|
2010-09-07 13:39:02 +08:00
|
|
|
case Instruction::And:
|
|
|
|
Result.markConstantRange(LHSRange.binaryAnd(RHSRange));
|
|
|
|
break;
|
|
|
|
case Instruction::Or:
|
|
|
|
Result.markConstantRange(LHSRange.binaryOr(RHSRange));
|
|
|
|
break;
|
2010-08-19 05:11:37 +08:00
|
|
|
|
|
|
|
// Unhandled instructions are overdefined.
|
|
|
|
default:
|
|
|
|
DEBUG(dbgs() << " compute BB '" << BB->getName()
|
|
|
|
<< "' - overdefined because inst def found.\n");
|
|
|
|
Result.markOverdefined();
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
2010-12-21 02:18:16 +08:00
|
|
|
BBLV = Result;
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
2009-11-12 06:48:44 +08:00
|
|
|
}
|
|
|
|
|
2012-06-28 09:16:18 +08:00
|
|
|
/// \brief Compute the value of Val on the edge BBFrom -> BBTo. Returns false if
|
|
|
|
/// Val is not constrained on the edge.
|
|
|
|
static bool getEdgeValueLocal(Value *Val, BasicBlock *BBFrom,
|
|
|
|
BasicBlock *BBTo, LVILatticeVal &Result) {
|
2009-11-16 04:02:12 +08:00
|
|
|
// TODO: Handle more complex conditionals. If (v == 0 || v2 < 1) is false, we
|
|
|
|
// know that v != 0.
|
2009-11-16 03:59:49 +08:00
|
|
|
if (BranchInst *BI = dyn_cast<BranchInst>(BBFrom->getTerminator())) {
|
|
|
|
// If this is a conditional branch and only one successor goes to BBTo, then
|
|
|
|
// we maybe able to infer something from the condition.
|
|
|
|
if (BI->isConditional() &&
|
|
|
|
BI->getSuccessor(0) != BI->getSuccessor(1)) {
|
|
|
|
bool isTrueDest = BI->getSuccessor(0) == BBTo;
|
|
|
|
assert(BI->getSuccessor(!isTrueDest) == BBTo &&
|
|
|
|
"BBTo isn't a successor of BBFrom");
|
|
|
|
|
|
|
|
// If V is the condition of the branch itself, then we know exactly what
|
|
|
|
// it is.
|
2010-12-18 09:00:40 +08:00
|
|
|
if (BI->getCondition() == Val) {
|
|
|
|
Result = LVILatticeVal::get(ConstantInt::get(
|
2010-08-11 04:03:09 +08:00
|
|
|
Type::getInt1Ty(Val->getContext()), isTrueDest));
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
|
|
|
}
|
2009-11-16 03:59:49 +08:00
|
|
|
|
|
|
|
// If the condition of the branch is an equality comparison, we may be
|
|
|
|
// able to infer the value.
|
2010-08-11 12:24:25 +08:00
|
|
|
ICmpInst *ICI = dyn_cast<ICmpInst>(BI->getCondition());
|
2012-03-02 23:34:43 +08:00
|
|
|
if (ICI && isa<Constant>(ICI->getOperand(1))) {
|
|
|
|
if (ICI->isEquality() && ICI->getOperand(0) == Val) {
|
2010-08-11 12:24:25 +08:00
|
|
|
// We know that V has the RHS constant if this is a true SETEQ or
|
|
|
|
// false SETNE.
|
|
|
|
if (isTrueDest == (ICI->getPredicate() == ICmpInst::ICMP_EQ))
|
2010-12-18 09:00:40 +08:00
|
|
|
Result = LVILatticeVal::get(cast<Constant>(ICI->getOperand(1)));
|
|
|
|
else
|
|
|
|
Result = LVILatticeVal::getNot(cast<Constant>(ICI->getOperand(1)));
|
|
|
|
return true;
|
2010-08-11 12:24:25 +08:00
|
|
|
}
|
2010-12-18 09:00:40 +08:00
|
|
|
|
2012-03-02 23:34:43 +08:00
|
|
|
// Recognize the range checking idiom that InstCombine produces.
|
|
|
|
// (X-C1) u< C2 --> [C1, C1+C2)
|
|
|
|
ConstantInt *NegOffset = 0;
|
|
|
|
if (ICI->getPredicate() == ICmpInst::ICMP_ULT)
|
|
|
|
match(ICI->getOperand(0), m_Add(m_Specific(Val),
|
|
|
|
m_ConstantInt(NegOffset)));
|
|
|
|
|
|
|
|
ConstantInt *CI = dyn_cast<ConstantInt>(ICI->getOperand(1));
|
|
|
|
if (CI && (ICI->getOperand(0) == Val || NegOffset)) {
|
2010-08-11 12:24:25 +08:00
|
|
|
// Calculate the range of values that would satisfy the comparison.
|
2012-05-18 07:04:08 +08:00
|
|
|
ConstantRange CmpRange(CI->getValue());
|
2010-08-11 12:24:25 +08:00
|
|
|
ConstantRange TrueValues =
|
|
|
|
ConstantRange::makeICmpRegion(ICI->getPredicate(), CmpRange);
|
2010-12-18 09:00:40 +08:00
|
|
|
|
2012-03-02 23:34:43 +08:00
|
|
|
if (NegOffset) // Apply the offset from above.
|
|
|
|
TrueValues = TrueValues.subtract(NegOffset->getValue());
|
|
|
|
|
2010-08-11 12:24:25 +08:00
|
|
|
// If we're interested in the false dest, invert the condition.
|
|
|
|
if (!isTrueDest) TrueValues = TrueValues.inverse();
|
2012-06-28 09:16:18 +08:00
|
|
|
|
|
|
|
Result = LVILatticeVal::getRange(TrueValues);
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
2009-11-16 03:59:49 +08:00
|
|
|
}
|
2010-08-11 12:24:25 +08:00
|
|
|
}
|
2009-11-16 03:59:49 +08:00
|
|
|
}
|
|
|
|
}
|
2009-11-16 04:02:12 +08:00
|
|
|
|
|
|
|
// If the edge was formed by a switch on the value, then we may know exactly
|
|
|
|
// what it is.
|
|
|
|
if (SwitchInst *SI = dyn_cast<SwitchInst>(BBFrom->getTerminator())) {
|
2012-06-29 00:13:37 +08:00
|
|
|
if (SI->getCondition() != Val)
|
|
|
|
return false;
|
|
|
|
|
|
|
|
bool DefaultCase = SI->getDefaultDest() == BBTo;
|
|
|
|
unsigned BitWidth = Val->getType()->getIntegerBitWidth();
|
|
|
|
ConstantRange EdgesVals(BitWidth, DefaultCase/*isFullSet*/);
|
|
|
|
|
|
|
|
for (SwitchInst::CaseIt i = SI->case_begin(), e = SI->case_end();
|
|
|
|
i != e; ++i) {
|
|
|
|
ConstantRange EdgeVal(i.getCaseValue()->getValue());
|
2012-09-06 07:45:58 +08:00
|
|
|
if (DefaultCase) {
|
|
|
|
// It is possible that the default destination is the destination of
|
|
|
|
// some cases. There is no need to perform difference for those cases.
|
|
|
|
if (i.getCaseSuccessor() != BBTo)
|
|
|
|
EdgesVals = EdgesVals.difference(EdgeVal);
|
|
|
|
} else if (i.getCaseSuccessor() == BBTo)
|
2012-05-19 05:02:10 +08:00
|
|
|
EdgesVals = EdgesVals.unionWith(EdgeVal);
|
2009-11-16 04:02:12 +08:00
|
|
|
}
|
2012-06-29 00:13:37 +08:00
|
|
|
Result = LVILatticeVal::getRange(EdgesVals);
|
|
|
|
return true;
|
2009-11-16 04:02:12 +08:00
|
|
|
}
|
2012-06-28 09:16:18 +08:00
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
/// \brief Compute the value of Val on the edge BBFrom -> BBTo, or the value at
|
|
|
|
/// the basic block if the edge does not constraint Val.
|
|
|
|
bool LazyValueInfoCache::getEdgeValue(Value *Val, BasicBlock *BBFrom,
|
|
|
|
BasicBlock *BBTo, LVILatticeVal &Result) {
|
|
|
|
// If already a constant, there is nothing to compute.
|
|
|
|
if (Constant *VC = dyn_cast<Constant>(Val)) {
|
|
|
|
Result = LVILatticeVal::get(VC);
|
2010-12-18 09:00:40 +08:00
|
|
|
return true;
|
|
|
|
}
|
2012-06-28 09:16:18 +08:00
|
|
|
|
|
|
|
if (getEdgeValueLocal(Val, BBFrom, BBTo, Result)) {
|
|
|
|
if (!Result.isConstantRange() ||
|
|
|
|
Result.getConstantRange().getSingleElement())
|
|
|
|
return true;
|
|
|
|
|
|
|
|
// FIXME: this check should be moved to the beginning of the function when
|
|
|
|
// LVI better supports recursive values. Even for the single value case, we
|
|
|
|
// can intersect to detect dead code (an empty range).
|
|
|
|
if (!hasBlockValue(Val, BBFrom)) {
|
|
|
|
BlockValueStack.push(std::make_pair(BBFrom, Val));
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
// Try to intersect ranges of the BB and the constraint on the edge.
|
|
|
|
LVILatticeVal InBlock = getBlockValue(Val, BBFrom);
|
|
|
|
if (!InBlock.isConstantRange())
|
|
|
|
return true;
|
|
|
|
|
|
|
|
ConstantRange Range =
|
|
|
|
Result.getConstantRange().intersectWith(InBlock.getConstantRange());
|
|
|
|
Result = LVILatticeVal::getRange(Range);
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!hasBlockValue(Val, BBFrom)) {
|
|
|
|
BlockValueStack.push(std::make_pair(BBFrom, Val));
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
// if we couldn't compute the value on the edge, use the value from the BB
|
|
|
|
Result = getBlockValue(Val, BBFrom);
|
|
|
|
return true;
|
2009-11-16 03:59:49 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
LVILatticeVal LazyValueInfoCache::getValueInBlock(Value *V, BasicBlock *BB) {
|
2009-12-24 04:43:58 +08:00
|
|
|
DEBUG(dbgs() << "LVI Getting block end value " << *V << " at '"
|
2009-11-16 03:59:49 +08:00
|
|
|
<< BB->getName() << "'\n");
|
|
|
|
|
2011-01-06 07:26:22 +08:00
|
|
|
BlockValueStack.push(std::make_pair(BB, V));
|
2010-12-18 09:00:40 +08:00
|
|
|
solve();
|
2010-12-09 14:14:58 +08:00
|
|
|
LVILatticeVal Result = getBlockValue(V, BB);
|
2010-12-18 09:00:40 +08:00
|
|
|
|
2009-12-24 04:43:58 +08:00
|
|
|
DEBUG(dbgs() << " Result = " << Result << "\n");
|
2009-11-16 03:59:49 +08:00
|
|
|
return Result;
|
|
|
|
}
|
|
|
|
|
|
|
|
LVILatticeVal LazyValueInfoCache::
|
|
|
|
getValueOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB) {
|
2009-12-24 04:43:58 +08:00
|
|
|
DEBUG(dbgs() << "LVI Getting edge value " << *V << " from '"
|
2009-11-16 03:59:49 +08:00
|
|
|
<< FromBB->getName() << "' to '" << ToBB->getName() << "'\n");
|
2010-07-27 02:48:03 +08:00
|
|
|
|
2010-12-18 09:00:40 +08:00
|
|
|
LVILatticeVal Result;
|
|
|
|
if (!getEdgeValue(V, FromBB, ToBB, Result)) {
|
|
|
|
solve();
|
|
|
|
bool WasFastQuery = getEdgeValue(V, FromBB, ToBB, Result);
|
|
|
|
(void)WasFastQuery;
|
|
|
|
assert(WasFastQuery && "More work to do after problem solved?");
|
|
|
|
}
|
|
|
|
|
2009-12-24 04:43:58 +08:00
|
|
|
DEBUG(dbgs() << " Result = " << Result << "\n");
|
2009-11-16 03:59:49 +08:00
|
|
|
return Result;
|
|
|
|
}
|
|
|
|
|
2010-07-27 02:48:03 +08:00
|
|
|
void LazyValueInfoCache::threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc,
|
|
|
|
BasicBlock *NewSucc) {
|
|
|
|
// When an edge in the graph has been threaded, values that we could not
|
|
|
|
// determine a value for before (i.e. were marked overdefined) may be possible
|
|
|
|
// to solve now. We do NOT try to proactively update these values. Instead,
|
|
|
|
// we clear their entries from the cache, and allow lazy updating to recompute
|
|
|
|
// them when needed.
|
|
|
|
|
|
|
|
// The updating process is fairly simple: we need to dropped cached info
|
|
|
|
// for all values that were marked overdefined in OldSucc, and for those same
|
|
|
|
// values in any successor of OldSucc (except NewSucc) in which they were
|
|
|
|
// also marked overdefined.
|
|
|
|
std::vector<BasicBlock*> worklist;
|
|
|
|
worklist.push_back(OldSucc);
|
|
|
|
|
2010-07-28 07:58:11 +08:00
|
|
|
DenseSet<Value*> ClearSet;
|
2011-01-06 05:15:29 +08:00
|
|
|
for (DenseSet<OverDefinedPairTy>::iterator I = OverDefinedCache.begin(),
|
|
|
|
E = OverDefinedCache.end(); I != E; ++I) {
|
2010-07-28 07:58:11 +08:00
|
|
|
if (I->first == OldSucc)
|
|
|
|
ClearSet.insert(I->second);
|
|
|
|
}
|
2010-07-27 02:48:03 +08:00
|
|
|
|
|
|
|
// Use a worklist to perform a depth-first search of OldSucc's successors.
|
|
|
|
// NOTE: We do not need a visited list since any blocks we have already
|
|
|
|
// visited will have had their overdefined markers cleared already, and we
|
|
|
|
// thus won't loop to their successors.
|
|
|
|
while (!worklist.empty()) {
|
|
|
|
BasicBlock *ToUpdate = worklist.back();
|
|
|
|
worklist.pop_back();
|
|
|
|
|
|
|
|
// Skip blocks only accessible through NewSucc.
|
|
|
|
if (ToUpdate == NewSucc) continue;
|
|
|
|
|
|
|
|
bool changed = false;
|
2010-12-16 02:57:18 +08:00
|
|
|
for (DenseSet<Value*>::iterator I = ClearSet.begin(), E = ClearSet.end();
|
2010-07-27 02:48:03 +08:00
|
|
|
I != E; ++I) {
|
|
|
|
// If a value was marked overdefined in OldSucc, and is here too...
|
2011-01-06 05:15:29 +08:00
|
|
|
DenseSet<OverDefinedPairTy>::iterator OI =
|
2010-07-28 07:58:11 +08:00
|
|
|
OverDefinedCache.find(std::make_pair(ToUpdate, *I));
|
|
|
|
if (OI == OverDefinedCache.end()) continue;
|
|
|
|
|
|
|
|
// Remove it from the caches.
|
2010-07-31 07:59:40 +08:00
|
|
|
ValueCacheEntryTy &Entry = ValueCache[LVIValueHandle(*I, this)];
|
2010-07-28 07:58:11 +08:00
|
|
|
ValueCacheEntryTy::iterator CI = Entry.find(ToUpdate);
|
2010-12-18 09:00:40 +08:00
|
|
|
|
2010-07-28 07:58:11 +08:00
|
|
|
assert(CI != Entry.end() && "Couldn't find entry to update?");
|
|
|
|
Entry.erase(CI);
|
|
|
|
OverDefinedCache.erase(OI);
|
|
|
|
|
|
|
|
// If we removed anything, then we potentially need to update
|
|
|
|
// blocks successors too.
|
|
|
|
changed = true;
|
2010-07-27 02:48:03 +08:00
|
|
|
}
|
2010-12-18 09:00:40 +08:00
|
|
|
|
2010-07-27 02:48:03 +08:00
|
|
|
if (!changed) continue;
|
|
|
|
|
|
|
|
worklist.insert(worklist.end(), succ_begin(ToUpdate), succ_end(ToUpdate));
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2009-11-16 03:59:49 +08:00
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// LazyValueInfo Impl
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
|
|
|
|
/// getCache - This lazily constructs the LazyValueInfoCache.
|
|
|
|
static LazyValueInfoCache &getCache(void *&PImpl) {
|
|
|
|
if (!PImpl)
|
|
|
|
PImpl = new LazyValueInfoCache();
|
|
|
|
return *static_cast<LazyValueInfoCache*>(PImpl);
|
|
|
|
}
|
|
|
|
|
2010-08-19 02:39:01 +08:00
|
|
|
bool LazyValueInfo::runOnFunction(Function &F) {
|
|
|
|
if (PImpl)
|
|
|
|
getCache(PImpl).clear();
|
2011-12-02 09:26:24 +08:00
|
|
|
|
2012-10-09 00:38:25 +08:00
|
|
|
TD = getAnalysisIfAvailable<DataLayout>();
|
2011-12-02 09:26:24 +08:00
|
|
|
TLI = &getAnalysis<TargetLibraryInfo>();
|
|
|
|
|
2010-08-19 02:39:01 +08:00
|
|
|
// Fully lazy.
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
2011-12-02 09:26:24 +08:00
|
|
|
void LazyValueInfo::getAnalysisUsage(AnalysisUsage &AU) const {
|
|
|
|
AU.setPreservesAll();
|
|
|
|
AU.addRequired<TargetLibraryInfo>();
|
|
|
|
}
|
|
|
|
|
2009-11-16 03:59:49 +08:00
|
|
|
void LazyValueInfo::releaseMemory() {
|
|
|
|
// If the cache was allocated, free it.
|
|
|
|
if (PImpl) {
|
|
|
|
delete &getCache(PImpl);
|
|
|
|
PImpl = 0;
|
|
|
|
}
|
|
|
|
}
|
2009-11-12 06:48:44 +08:00
|
|
|
|
2009-11-16 03:59:49 +08:00
|
|
|
Constant *LazyValueInfo::getConstant(Value *V, BasicBlock *BB) {
|
|
|
|
LVILatticeVal Result = getCache(PImpl).getValueInBlock(V, BB);
|
|
|
|
|
2009-11-12 06:48:44 +08:00
|
|
|
if (Result.isConstant())
|
|
|
|
return Result.getConstant();
|
2010-12-16 02:57:18 +08:00
|
|
|
if (Result.isConstantRange()) {
|
2010-08-28 07:29:38 +08:00
|
|
|
ConstantRange CR = Result.getConstantRange();
|
|
|
|
if (const APInt *SingleVal = CR.getSingleElement())
|
|
|
|
return ConstantInt::get(V->getContext(), *SingleVal);
|
|
|
|
}
|
2009-11-12 06:48:44 +08:00
|
|
|
return 0;
|
|
|
|
}
|
2009-11-11 10:08:33 +08:00
|
|
|
|
2009-11-12 09:29:10 +08:00
|
|
|
/// getConstantOnEdge - Determine whether the specified value is known to be a
|
|
|
|
/// constant on the specified edge. Return null if not.
|
|
|
|
Constant *LazyValueInfo::getConstantOnEdge(Value *V, BasicBlock *FromBB,
|
|
|
|
BasicBlock *ToBB) {
|
2009-11-16 03:59:49 +08:00
|
|
|
LVILatticeVal Result = getCache(PImpl).getValueOnEdge(V, FromBB, ToBB);
|
2009-11-12 09:29:10 +08:00
|
|
|
|
|
|
|
if (Result.isConstant())
|
|
|
|
return Result.getConstant();
|
2010-12-16 02:57:18 +08:00
|
|
|
if (Result.isConstantRange()) {
|
2010-08-11 04:03:09 +08:00
|
|
|
ConstantRange CR = Result.getConstantRange();
|
|
|
|
if (const APInt *SingleVal = CR.getSingleElement())
|
|
|
|
return ConstantInt::get(V->getContext(), *SingleVal);
|
|
|
|
}
|
2009-11-12 09:29:10 +08:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2009-11-12 12:36:58 +08:00
|
|
|
/// getPredicateOnEdge - Determine whether the specified value comparison
|
|
|
|
/// with a constant is known to be true or false on the specified CFG edge.
|
|
|
|
/// Pred is a CmpInst predicate.
|
2009-11-11 10:08:33 +08:00
|
|
|
LazyValueInfo::Tristate
|
2009-11-12 12:36:58 +08:00
|
|
|
LazyValueInfo::getPredicateOnEdge(unsigned Pred, Value *V, Constant *C,
|
|
|
|
BasicBlock *FromBB, BasicBlock *ToBB) {
|
2009-11-16 03:59:49 +08:00
|
|
|
LVILatticeVal Result = getCache(PImpl).getValueOnEdge(V, FromBB, ToBB);
|
2009-11-12 12:36:58 +08:00
|
|
|
|
|
|
|
// If we know the value is a constant, evaluate the conditional.
|
|
|
|
Constant *Res = 0;
|
|
|
|
if (Result.isConstant()) {
|
2011-12-02 09:26:24 +08:00
|
|
|
Res = ConstantFoldCompareInstOperands(Pred, Result.getConstant(), C, TD,
|
|
|
|
TLI);
|
2010-12-16 02:57:18 +08:00
|
|
|
if (ConstantInt *ResCI = dyn_cast<ConstantInt>(Res))
|
2009-11-12 12:36:58 +08:00
|
|
|
return ResCI->isZero() ? False : True;
|
2009-11-16 03:59:49 +08:00
|
|
|
return Unknown;
|
|
|
|
}
|
|
|
|
|
2010-08-11 04:03:09 +08:00
|
|
|
if (Result.isConstantRange()) {
|
2010-08-24 15:55:44 +08:00
|
|
|
ConstantInt *CI = dyn_cast<ConstantInt>(C);
|
|
|
|
if (!CI) return Unknown;
|
|
|
|
|
2010-08-11 04:03:09 +08:00
|
|
|
ConstantRange CR = Result.getConstantRange();
|
|
|
|
if (Pred == ICmpInst::ICMP_EQ) {
|
|
|
|
if (!CR.contains(CI->getValue()))
|
|
|
|
return False;
|
|
|
|
|
|
|
|
if (CR.isSingleElement() && CR.contains(CI->getValue()))
|
|
|
|
return True;
|
|
|
|
} else if (Pred == ICmpInst::ICMP_NE) {
|
|
|
|
if (!CR.contains(CI->getValue()))
|
|
|
|
return True;
|
|
|
|
|
|
|
|
if (CR.isSingleElement() && CR.contains(CI->getValue()))
|
|
|
|
return False;
|
|
|
|
}
|
|
|
|
|
|
|
|
// Handle more complex predicates.
|
2010-12-16 02:57:18 +08:00
|
|
|
ConstantRange TrueValues =
|
|
|
|
ICmpInst::makeConstantRange((ICmpInst::Predicate)Pred, CI->getValue());
|
|
|
|
if (TrueValues.contains(CR))
|
2010-08-11 04:03:09 +08:00
|
|
|
return True;
|
2010-12-16 02:57:18 +08:00
|
|
|
if (TrueValues.inverse().contains(CR))
|
|
|
|
return False;
|
2010-08-11 04:03:09 +08:00
|
|
|
return Unknown;
|
|
|
|
}
|
|
|
|
|
2009-11-16 03:59:49 +08:00
|
|
|
if (Result.isNotConstant()) {
|
2009-11-12 12:36:58 +08:00
|
|
|
// If this is an equality comparison, we can try to fold it knowing that
|
|
|
|
// "V != C1".
|
|
|
|
if (Pred == ICmpInst::ICMP_EQ) {
|
2012-09-27 18:14:43 +08:00
|
|
|
// !C1 == C -> false iff C1 == C.
|
2009-11-12 12:36:58 +08:00
|
|
|
Res = ConstantFoldCompareInstOperands(ICmpInst::ICMP_NE,
|
2011-12-02 09:26:24 +08:00
|
|
|
Result.getNotConstant(), C, TD,
|
|
|
|
TLI);
|
2009-11-12 12:36:58 +08:00
|
|
|
if (Res->isNullValue())
|
|
|
|
return False;
|
|
|
|
} else if (Pred == ICmpInst::ICMP_NE) {
|
2012-09-27 18:14:43 +08:00
|
|
|
// !C1 != C -> true iff C1 == C.
|
2009-11-16 04:01:24 +08:00
|
|
|
Res = ConstantFoldCompareInstOperands(ICmpInst::ICMP_NE,
|
2011-12-02 09:26:24 +08:00
|
|
|
Result.getNotConstant(), C, TD,
|
|
|
|
TLI);
|
2009-11-12 12:36:58 +08:00
|
|
|
if (Res->isNullValue())
|
|
|
|
return True;
|
|
|
|
}
|
2009-11-16 03:59:49 +08:00
|
|
|
return Unknown;
|
2009-11-11 10:08:33 +08:00
|
|
|
}
|
2009-11-11 08:22:30 +08:00
|
|
|
|
2009-11-11 10:08:33 +08:00
|
|
|
return Unknown;
|
2009-11-11 08:22:30 +08:00
|
|
|
}
|
2009-11-11 10:08:33 +08:00
|
|
|
|
2010-07-27 02:48:03 +08:00
|
|
|
void LazyValueInfo::threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc,
|
2010-12-16 02:57:18 +08:00
|
|
|
BasicBlock *NewSucc) {
|
2010-08-19 02:39:01 +08:00
|
|
|
if (PImpl) getCache(PImpl).threadEdge(PredBB, OldSucc, NewSucc);
|
|
|
|
}
|
|
|
|
|
|
|
|
void LazyValueInfo::eraseBlock(BasicBlock *BB) {
|
|
|
|
if (PImpl) getCache(PImpl).eraseBlock(BB);
|
2010-07-27 02:48:03 +08:00
|
|
|
}
|