[llvm-commits] [llvm] r148415 - /llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
Jakub Staszak
kubastaszak at gmail.com
Wed Jan 18 13:16:34 PST 2012
Author: kuba
Date: Wed Jan 18 15:16:33 2012
New Revision: 148415
URL: http://llvm.org/viewvc/llvm-project?rev=148415&view=rev
Log:
Remove trailing spaces and unneeded includes.
Modified:
llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SCCP.cpp?rev=148415&r1=148414&r2=148415&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SCCP.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SCCP.cpp Wed Jan 18 15:16:33 2012
@@ -25,7 +25,6 @@
#include "llvm/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetLibraryInfo.h"
@@ -40,9 +39,7 @@
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/STLExtras.h"
#include <algorithm>
-#include <map>
using namespace llvm;
STATISTIC(NumInstRemoved, "Number of instructions removed");
@@ -60,7 +57,7 @@
enum LatticeValueTy {
/// undefined - This LLVM Value has no known value yet.
undefined,
-
+
/// constant - This LLVM Value has a specific constant value.
constant,
@@ -69,7 +66,7 @@
/// with another (different) constant, it goes to overdefined, instead of
/// asserting.
forcedconstant,
-
+
/// overdefined - This instruction is not known to be constant, and we know
/// it has a value.
overdefined
@@ -78,30 +75,30 @@
/// Val: This stores the current lattice value along with the Constant* for
/// the constant if this is a 'constant' or 'forcedconstant' value.
PointerIntPair<Constant *, 2, LatticeValueTy> Val;
-
+
LatticeValueTy getLatticeValue() const {
return Val.getInt();
}
-
+
public:
LatticeVal() : Val(0, undefined) {}
-
+
bool isUndefined() const { return getLatticeValue() == undefined; }
bool isConstant() const {
return getLatticeValue() == constant || getLatticeValue() == forcedconstant;
}
bool isOverdefined() const { return getLatticeValue() == overdefined; }
-
+
Constant *getConstant() const {
assert(isConstant() && "Cannot get the constant of a non-constant!");
return Val.getPointer();
}
-
+
/// markOverdefined - Return true if this is a change in status.
bool markOverdefined() {
if (isOverdefined())
return false;
-
+
Val.setInt(overdefined);
return true;
}
@@ -112,17 +109,17 @@
assert(getConstant() == V && "Marking constant with different value");
return false;
}
-
+
if (isUndefined()) {
Val.setInt(constant);
assert(V && "Marking constant with NULL");
Val.setPointer(V);
} else {
- assert(getLatticeValue() == forcedconstant &&
+ assert(getLatticeValue() == forcedconstant &&
"Cannot move from overdefined to constant!");
// Stay at forcedconstant if the constant is the same.
if (V == getConstant()) return false;
-
+
// Otherwise, we go to overdefined. Assumptions made based on the
// forced value are possibly wrong. Assuming this is another constant
// could expose a contradiction.
@@ -138,7 +135,7 @@
return dyn_cast<ConstantInt>(getConstant());
return 0;
}
-
+
void markForcedConstant(Constant *V) {
assert(isUndefined() && "Can't force a defined value!");
Val.setInt(forcedconstant);
@@ -165,7 +162,7 @@
/// StructType, for example for formal arguments, calls, insertelement, etc.
///
DenseMap<std::pair<Value*, unsigned>, LatticeVal> StructValueState;
-
+
/// GlobalValue - If we are tracking any values for the contents of a global
/// variable, we keep a mapping from the constant accessor to the element of
/// the global, to the currently known value. If the value becomes
@@ -180,7 +177,7 @@
/// TrackedMultipleRetVals - Same as TrackedRetVals, but used for functions
/// that return multiple values.
DenseMap<std::pair<Function*, unsigned>, LatticeVal> TrackedMultipleRetVals;
-
+
/// MRVFunctionsTracked - Each function in TrackedMultipleRetVals is
/// represented here for efficient lookup.
SmallPtrSet<Function*, 16> MRVFunctionsTracked;
@@ -189,7 +186,7 @@
/// arguments we make optimistic assumptions about and try to prove as
/// constants.
SmallPtrSet<Function*, 16> TrackingIncomingArguments;
-
+
/// The reason for two worklists is that overdefined is the lowest state
/// on the lattice, and moving things to overdefined as fast as possible
/// makes SCCP converge much faster.
@@ -252,7 +249,7 @@
void AddArgumentTrackedFunction(Function *F) {
TrackingIncomingArguments.insert(F);
}
-
+
/// Solve - Solve for constants and executable blocks.
///
void Solve();
@@ -273,9 +270,9 @@
assert(I != ValueState.end() && "V is not in valuemap!");
return I->second;
}
-
+
/*LatticeVal getStructLatticeValueFor(Value *V, unsigned i) const {
- DenseMap<std::pair<Value*, unsigned>, LatticeVal>::const_iterator I =
+ DenseMap<std::pair<Value*, unsigned>, LatticeVal>::const_iterator I =
StructValueState.find(std::make_pair(V, i));
assert(I != StructValueState.end() && "V is not in valuemap!");
return I->second;
@@ -307,7 +304,7 @@
else
markOverdefined(V);
}
-
+
private:
// markConstant - Make a value be marked as "constant". If the value
// is not already a constant, add it to the instruction work list so that
@@ -321,7 +318,7 @@
else
InstWorkList.push_back(V);
}
-
+
void markConstant(Value *V, Constant *C) {
assert(!V->getType()->isStructTy() && "Should use other method");
markConstant(ValueState[V], V, C);
@@ -337,14 +334,14 @@
else
InstWorkList.push_back(V);
}
-
-
+
+
// markOverdefined - Make a value be marked as "overdefined". If the
// value is not already overdefined, add it to the overdefined instruction
// work list so that the users of the instruction are updated later.
void markOverdefined(LatticeVal &IV, Value *V) {
if (!IV.markOverdefined()) return;
-
+
DEBUG(dbgs() << "markOverdefined: ";
if (Function *F = dyn_cast<Function>(V))
dbgs() << "Function '" << F->getName() << "'\n";
@@ -364,7 +361,7 @@
else if (IV.getConstant() != MergeWithV.getConstant())
markOverdefined(IV, V);
}
-
+
void mergeInValue(Value *V, LatticeVal MergeWithV) {
assert(!V->getType()->isStructTy() && "Should use other method");
mergeInValue(ValueState[V], V, MergeWithV);
@@ -389,7 +386,7 @@
if (!isa<UndefValue>(V))
LV.markConstant(C); // Constants are constant
}
-
+
// All others are underdefined by default.
return LV;
}
@@ -421,11 +418,11 @@
} else
LV.markOverdefined(); // Unknown sort of constant.
}
-
+
// All others are underdefined by default.
return LV;
}
-
+
/// markEdgeExecutable - Mark a basic block as executable, adding it to the BB
/// work list if it is not already executable.
@@ -531,7 +528,7 @@
Succs[0] = true;
return;
}
-
+
LatticeVal BCValue = getValueState(BI->getCondition());
ConstantInt *CI = BCValue.getConstantInt();
if (CI == 0) {
@@ -541,18 +538,18 @@
Succs[0] = Succs[1] = true;
return;
}
-
+
// Constant condition variables mean the branch can only go a single way.
Succs[CI->isZero()] = true;
return;
}
-
+
if (isa<InvokeInst>(TI)) {
// Invoke instructions successors are always executable.
Succs[0] = Succs[1] = true;
return;
}
-
+
if (SwitchInst *SI = dyn_cast<SwitchInst>(&TI)) {
if (TI.getNumSuccessors() < 2) {
Succs[0] = true;
@@ -560,25 +557,25 @@
}
LatticeVal SCValue = getValueState(SI->getCondition());
ConstantInt *CI = SCValue.getConstantInt();
-
+
if (CI == 0) { // Overdefined or undefined condition?
// All destinations are executable!
if (!SCValue.isUndefined())
Succs.assign(TI.getNumSuccessors(), true);
return;
}
-
+
Succs[SI->findCaseValue(CI)] = true;
return;
}
-
+
// TODO: This could be improved if the operand is a [cast of a] BlockAddress.
if (isa<IndirectBrInst>(&TI)) {
// Just mark all destinations executable!
Succs.assign(TI.getNumSuccessors(), true);
return;
}
-
+
#ifndef NDEBUG
dbgs() << "Unknown terminator instruction: " << TI << '\n';
#endif
@@ -600,7 +597,7 @@
if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
if (BI->isUnconditional())
return true;
-
+
LatticeVal BCValue = getValueState(BI->getCondition());
// Overdefined condition variables mean the branch could go either way,
@@ -608,22 +605,22 @@
ConstantInt *CI = BCValue.getConstantInt();
if (CI == 0)
return !BCValue.isUndefined();
-
+
// Constant condition variables mean the branch can only go a single way.
return BI->getSuccessor(CI->isZero()) == To;
}
-
+
// Invoke instructions successors are always executable.
if (isa<InvokeInst>(TI))
return true;
-
+
if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
if (SI->getNumSuccessors() < 2)
return true;
LatticeVal SCValue = getValueState(SI->getCondition());
ConstantInt *CI = SCValue.getConstantInt();
-
+
if (CI == 0)
return !SCValue.isUndefined();
@@ -636,12 +633,12 @@
// execute default branch.
return SI->getDefaultDest() == To;
}
-
+
// Just mark all destinations executable!
// TODO: This could be improved if the operand is a [cast of a] BlockAddress.
if (isa<IndirectBrInst>(TI))
return true;
-
+
#ifndef NDEBUG
dbgs() << "Unknown terminator instruction: " << *TI << '\n';
#endif
@@ -671,7 +668,7 @@
// TODO: We could do a lot better than this if code actually uses this.
if (PN.getType()->isStructTy())
return markAnythingOverdefined(&PN);
-
+
if (getValueState(&PN).isOverdefined())
return; // Quick exit
@@ -679,7 +676,7 @@
// and slow us down a lot. Just mark them overdefined.
if (PN.getNumIncomingValues() > 64)
return markOverdefined(&PN);
-
+
// Look at all of the executable operands of the PHI node. If any of them
// are overdefined, the PHI becomes overdefined as well. If they are all
// constant, and they agree with each other, the PHI becomes the identical
@@ -693,7 +690,7 @@
if (!isEdgeFeasible(PN.getIncomingBlock(i), PN.getParent()))
continue;
-
+
if (IV.isOverdefined()) // PHI node becomes overdefined!
return markOverdefined(&PN);
@@ -701,11 +698,11 @@
OperandVal = IV.getConstant();
continue;
}
-
+
// There is already a reachable operand. If we conflict with it,
// then the PHI node becomes overdefined. If we agree with it, we
// can continue on.
-
+
// Check to see if there are two different constants merging, if so, the PHI
// node is overdefined.
if (IV.getConstant() != OperandVal)
@@ -729,7 +726,7 @@
Function *F = I.getParent()->getParent();
Value *ResultOp = I.getOperand(0);
-
+
// If we are tracking the return value of this function, merge it in.
if (!TrackedRetVals.empty() && !ResultOp->getType()->isStructTy()) {
DenseMap<Function*, LatticeVal>::iterator TFRVI =
@@ -739,7 +736,7 @@
return;
}
}
-
+
// Handle functions that return multiple values.
if (!TrackedMultipleRetVals.empty()) {
if (StructType *STy = dyn_cast<StructType>(ResultOp->getType()))
@@ -747,7 +744,7 @@
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
mergeInValue(TrackedMultipleRetVals[std::make_pair(F, i)], F,
getStructValueState(ResultOp, i));
-
+
}
}
@@ -768,7 +765,7 @@
if (OpSt.isOverdefined()) // Inherit overdefinedness of operand
markOverdefined(&I);
else if (OpSt.isConstant()) // Propagate constant value
- markConstant(&I, ConstantExpr::getCast(I.getOpcode(),
+ markConstant(&I, ConstantExpr::getCast(I.getOpcode(),
OpSt.getConstant(), I.getType()));
}
@@ -778,7 +775,7 @@
// structs in structs.
if (EVI.getType()->isStructTy())
return markAnythingOverdefined(&EVI);
-
+
// If this is extracting from more than one level of struct, we don't know.
if (EVI.getNumIndices() != 1)
return markOverdefined(&EVI);
@@ -798,15 +795,15 @@
StructType *STy = dyn_cast<StructType>(IVI.getType());
if (STy == 0)
return markOverdefined(&IVI);
-
+
// If this has more than one index, we can't handle it, drive all results to
// undef.
if (IVI.getNumIndices() != 1)
return markAnythingOverdefined(&IVI);
-
+
Value *Aggr = IVI.getAggregateOperand();
unsigned Idx = *IVI.idx_begin();
-
+
// Compute the result based on what we're inserting.
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
// This passes through all values that aren't the inserted element.
@@ -815,7 +812,7 @@
mergeInValue(getStructValueState(&IVI, i), &IVI, EltVal);
continue;
}
-
+
Value *Val = IVI.getInsertedValueOperand();
if (Val->getType()->isStructTy())
// We don't track structs in structs.
@@ -832,25 +829,25 @@
// TODO: We could do a lot better than this if code actually uses this.
if (I.getType()->isStructTy())
return markAnythingOverdefined(&I);
-
+
LatticeVal CondValue = getValueState(I.getCondition());
if (CondValue.isUndefined())
return;
-
+
if (ConstantInt *CondCB = CondValue.getConstantInt()) {
Value *OpVal = CondCB->isZero() ? I.getFalseValue() : I.getTrueValue();
mergeInValue(&I, getValueState(OpVal));
return;
}
-
+
// Otherwise, the condition is overdefined or a constant we can't evaluate.
// See if we can produce something better than overdefined based on the T/F
// value.
LatticeVal TVal = getValueState(I.getTrueValue());
LatticeVal FVal = getValueState(I.getFalseValue());
-
+
// select ?, C, C -> C.
- if (TVal.isConstant() && FVal.isConstant() &&
+ if (TVal.isConstant() && FVal.isConstant() &&
TVal.getConstant() == FVal.getConstant())
return markConstant(&I, FVal.getConstant());
@@ -865,7 +862,7 @@
void SCCPSolver::visitBinaryOperator(Instruction &I) {
LatticeVal V1State = getValueState(I.getOperand(0));
LatticeVal V2State = getValueState(I.getOperand(1));
-
+
LatticeVal &IV = ValueState[&I];
if (IV.isOverdefined()) return;
@@ -873,14 +870,14 @@
return markConstant(IV, &I,
ConstantExpr::get(I.getOpcode(), V1State.getConstant(),
V2State.getConstant()));
-
+
// If something is undef, wait for it to resolve.
if (!V1State.isOverdefined() && !V2State.isOverdefined())
return;
-
+
// Otherwise, one of our operands is overdefined. Try to produce something
// better than overdefined with some tricks.
-
+
// If this is an AND or OR with 0 or -1, it doesn't matter that the other
// operand is overdefined.
if (I.getOpcode() == Instruction::And || I.getOpcode() == Instruction::Or) {
@@ -902,7 +899,7 @@
Constant::getAllOnesValue(I.getType()));
return;
}
-
+
if (I.getOpcode() == Instruction::And) {
// X and 0 = 0
if (NonOverdefVal->getConstant()->isNullValue())
@@ -928,14 +925,14 @@
if (IV.isOverdefined()) return;
if (V1State.isConstant() && V2State.isConstant())
- return markConstant(IV, &I, ConstantExpr::getCompare(I.getPredicate(),
- V1State.getConstant(),
+ return markConstant(IV, &I, ConstantExpr::getCompare(I.getPredicate(),
+ V1State.getConstant(),
V2State.getConstant()));
-
+
// If operands are still undefined, wait for it to resolve.
if (!V1State.isOverdefined() && !V2State.isOverdefined())
return;
-
+
markOverdefined(&I);
}
@@ -972,7 +969,7 @@
EltState.getConstant(),
IdxState.getConstant()));
else if (ValState.isUndefined() && EltState.isConstant() &&
- IdxState.isConstant())
+ IdxState.isConstant())
markConstant(&I,ConstantExpr::getInsertElement(UndefValue::get(I.getType()),
EltState.getConstant(),
IdxState.getConstant()));
@@ -990,17 +987,17 @@
if (MaskState.isUndefined() ||
(V1State.isUndefined() && V2State.isUndefined()))
return; // Undefined output if mask or both inputs undefined.
-
+
if (V1State.isOverdefined() || V2State.isOverdefined() ||
MaskState.isOverdefined()) {
markOverdefined(&I);
} else {
// A mix of constant/undef inputs.
- Constant *V1 = V1State.isConstant() ?
+ Constant *V1 = V1State.isConstant() ?
V1State.getConstant() : UndefValue::get(I.getType());
- Constant *V2 = V2State.isConstant() ?
+ Constant *V2 = V2State.isConstant() ?
V2State.getConstant() : UndefValue::get(I.getType());
- Constant *Mask = MaskState.isConstant() ?
+ Constant *Mask = MaskState.isConstant() ?
MaskState.getConstant() : UndefValue::get(I.getOperand(2)->getType());
markConstant(&I, ConstantExpr::getShuffleVector(V1, V2, Mask));
}
@@ -1020,7 +1017,7 @@
LatticeVal State = getValueState(I.getOperand(i));
if (State.isUndefined())
return; // Operands are not resolved yet.
-
+
if (State.isOverdefined())
return markOverdefined(&I);
@@ -1037,10 +1034,10 @@
// If this store is of a struct, ignore it.
if (SI.getOperand(0)->getType()->isStructTy())
return;
-
+
if (TrackedGlobals.empty() || !isa<GlobalVariable>(SI.getOperand(1)))
return;
-
+
GlobalVariable *GV = cast<GlobalVariable>(SI.getOperand(1));
DenseMap<GlobalVariable*, LatticeVal>::iterator I = TrackedGlobals.find(GV);
if (I == TrackedGlobals.end() || I->second.isOverdefined()) return;
@@ -1058,22 +1055,22 @@
// If this load is of a struct, just mark the result overdefined.
if (I.getType()->isStructTy())
return markAnythingOverdefined(&I);
-
+
LatticeVal PtrVal = getValueState(I.getOperand(0));
if (PtrVal.isUndefined()) return; // The pointer is not resolved yet!
-
+
LatticeVal &IV = ValueState[&I];
if (IV.isOverdefined()) return;
if (!PtrVal.isConstant() || I.isVolatile())
return markOverdefined(IV, &I);
-
+
Constant *Ptr = PtrVal.getConstant();
// load null -> null
if (isa<ConstantPointerNull>(Ptr) && I.getPointerAddressSpace() == 0)
return markConstant(IV, &I, Constant::getNullValue(I.getType()));
-
+
// Transform load (constant global) into the value loaded.
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Ptr)) {
if (!TrackedGlobals.empty()) {
@@ -1099,7 +1096,7 @@
void SCCPSolver::visitCallSite(CallSite CS) {
Function *F = CS.getCalledFunction();
Instruction *I = CS.getInstruction();
-
+
// The common case is that we aren't tracking the callee, either because we
// are not doing interprocedural analysis or the callee is indirect, or is
// external. Handle these cases first.
@@ -1107,17 +1104,17 @@
CallOverdefined:
// Void return and not tracking callee, just bail.
if (I->getType()->isVoidTy()) return;
-
+
// Otherwise, if we have a single return value case, and if the function is
// a declaration, maybe we can constant fold it.
if (F && F->isDeclaration() && !I->getType()->isStructTy() &&
canConstantFoldCallTo(F)) {
-
+
SmallVector<Constant*, 8> Operands;
for (CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
AI != E; ++AI) {
LatticeVal State = getValueState(*AI);
-
+
if (State.isUndefined())
return; // Operands are not resolved yet.
if (State.isOverdefined())
@@ -1125,7 +1122,7 @@
assert(State.isConstant() && "Unknown state!");
Operands.push_back(State.getConstant());
}
-
+
// If we can constant fold this, mark the result of the call as a
// constant.
if (Constant *C = ConstantFoldCall(F, Operands, TLI))
@@ -1141,7 +1138,7 @@
// the formal arguments of the function.
if (!TrackingIncomingArguments.empty() && TrackingIncomingArguments.count(F)){
MarkBlockExecutable(F->begin());
-
+
// Propagate information from this call site into the callee.
CallSite::arg_iterator CAI = CS.arg_begin();
for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
@@ -1152,7 +1149,7 @@
markOverdefined(AI);
continue;
}
-
+
if (StructType *STy = dyn_cast<StructType>(AI->getType())) {
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
LatticeVal CallArg = getStructValueState(*CAI, i);
@@ -1163,22 +1160,22 @@
}
}
}
-
+
// If this is a single/zero retval case, see if we're tracking the function.
if (StructType *STy = dyn_cast<StructType>(F->getReturnType())) {
if (!MRVFunctionsTracked.count(F))
goto CallOverdefined; // Not tracking this callee.
-
+
// If we are tracking this callee, propagate the result of the function
// into this call site.
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
- mergeInValue(getStructValueState(I, i), I,
+ mergeInValue(getStructValueState(I, i), I,
TrackedMultipleRetVals[std::make_pair(F, i)]);
} else {
DenseMap<Function*, LatticeVal>::iterator TFRVI = TrackedRetVals.find(F);
if (TFRVI == TrackedRetVals.end())
goto CallOverdefined; // Not tracking this callee.
-
+
// If so, propagate the return value of the callee into this call result.
mergeInValue(I, TFRVI->second);
}
@@ -1207,7 +1204,7 @@
if (Instruction *I = dyn_cast<Instruction>(*UI))
OperandChangedState(I);
}
-
+
// Process the instruction work list.
while (!InstWorkList.empty()) {
Value *I = InstWorkList.pop_back_val();
@@ -1264,11 +1261,11 @@
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
if (!BBExecutable.count(BB))
continue;
-
+
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
// Look for instructions which produce undef values.
if (I->getType()->isVoidTy()) continue;
-
+
if (StructType *STy = dyn_cast<StructType>(I->getType())) {
// Only a few things that can be structs matter for undef.
@@ -1279,7 +1276,7 @@
continue;
// extractvalue and insertvalue don't need to be marked; they are
- // tracked as precisely as their operands.
+ // tracked as precisely as their operands.
if (isa<ExtractValueInst>(I) || isa<InsertValueInst>(I))
continue;
@@ -1386,12 +1383,12 @@
// X / undef -> undef. No change.
// X % undef -> undef. No change.
if (Op1LV.isUndefined()) break;
-
+
// undef / X -> 0. X could be maxint.
// undef % X -> 0. X could be 1.
markForcedConstant(I, Constant::getNullValue(ITy));
return true;
-
+
case Instruction::AShr:
// X >>a undef -> undef.
if (Op1LV.isUndefined()) break;
@@ -1424,7 +1421,7 @@
} else {
// Leave Op1LV as Operand(1)'s LatticeValue.
}
-
+
if (Op1LV.isConstant())
markForcedConstant(I, Op1LV.getConstant());
else
@@ -1464,7 +1461,7 @@
return true;
}
}
-
+
// Check to see if we have a branch or switch on an undefined value. If so
// we force the branch to go one way or the other to make the successor
// values live. It doesn't really matter which way we force it.
@@ -1473,7 +1470,7 @@
if (!BI->isConditional()) continue;
if (!getValueState(BI->getCondition()).isUndefined())
continue;
-
+
// If the input to SCCP is actually branch on undef, fix the undef to
// false.
if (isa<UndefValue>(BI->getCondition())) {
@@ -1481,7 +1478,7 @@
markEdgeExecutable(BB, TI->getSuccessor(1));
return true;
}
-
+
// Otherwise, it is a branch on a symbolic value which is currently
// considered to be undef. Handle this by forcing the input value to the
// branch to false.
@@ -1489,13 +1486,13 @@
ConstantInt::getFalse(TI->getContext()));
return true;
}
-
+
if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
if (SI->getNumSuccessors() < 2) // no cases
continue;
if (!getValueState(SI->getCondition()).isUndefined())
continue;
-
+
// If the input to SCCP is actually switch on undef, fix the undef to
// the first constant.
if (isa<UndefValue>(SI->getCondition())) {
@@ -1503,7 +1500,7 @@
markEdgeExecutable(BB, TI->getSuccessor(1));
return true;
}
-
+
markForcedConstant(SI->getCondition(), SI->getCaseValue(1));
return true;
}
@@ -1606,7 +1603,7 @@
MadeChanges = true;
continue;
}
-
+
// Iterate over all of the instructions in a function, replacing them with
// constants if we have found them to be of constant values.
//
@@ -1614,25 +1611,25 @@
Instruction *Inst = BI++;
if (Inst->getType()->isVoidTy() || isa<TerminatorInst>(Inst))
continue;
-
+
// TODO: Reconstruct structs from their elements.
if (Inst->getType()->isStructTy())
continue;
-
+
LatticeVal IV = Solver.getLatticeValueFor(Inst);
if (IV.isOverdefined())
continue;
-
+
Constant *Const = IV.isConstant()
? IV.getConstant() : UndefValue::get(Inst->getType());
DEBUG(dbgs() << " Constant: " << *Const << " = " << *Inst);
// Replaces all of the uses of a variable with uses of the constant.
Inst->replaceAllUsesWith(Const);
-
+
// Delete the instruction.
Inst->eraseFromParent();
-
+
// Hey, we just changed something!
MadeChanges = true;
++NumInstRemoved;
@@ -1714,19 +1711,19 @@
// address-taken-ness. Because of this, we keep track of their addresses from
// the first pass so we can use them for the later simplification pass.
SmallPtrSet<Function*, 32> AddressTakenFunctions;
-
+
// Loop over all functions, marking arguments to those with their addresses
// taken or that are external as overdefined.
//
for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
if (F->isDeclaration())
continue;
-
+
// If this is a strong or ODR definition of this function, then we can
// propagate information about its result into callsites of it.
if (!F->mayBeOverridden())
Solver.AddTrackedFunction(F);
-
+
// If this function only has direct calls that we can see, we can track its
// arguments and return value aggressively, and can assume it is not called
// unless we see evidence to the contrary.
@@ -1741,7 +1738,7 @@
// Assume the function is called.
Solver.MarkBlockExecutable(F->begin());
-
+
// Assume nothing about the incoming arguments.
for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
AI != E; ++AI)
@@ -1779,17 +1776,17 @@
for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
AI != E; ++AI) {
if (AI->use_empty() || AI->getType()->isStructTy()) continue;
-
+
// TODO: Could use getStructLatticeValueFor to find out if the entire
// result is a constant and replace it entirely if so.
LatticeVal IV = Solver.getLatticeValueFor(AI);
if (IV.isOverdefined()) continue;
-
+
Constant *CST = IV.isConstant() ?
IV.getConstant() : UndefValue::get(AI->getType());
DEBUG(dbgs() << "*** Arg " << *AI << " = " << *CST <<"\n");
-
+
// Replaces all of the uses of a variable with uses of the
// constant.
AI->replaceAllUsesWith(CST);
@@ -1818,19 +1815,19 @@
new UnreachableInst(M.getContext(), BB);
continue;
}
-
+
for (BasicBlock::iterator BI = BB->begin(), E = BB->end(); BI != E; ) {
Instruction *Inst = BI++;
if (Inst->getType()->isVoidTy() || Inst->getType()->isStructTy())
continue;
-
+
// TODO: Could use getStructLatticeValueFor to find out if the entire
// result is a constant and replace it entirely if so.
-
+
LatticeVal IV = Solver.getLatticeValueFor(Inst);
if (IV.isOverdefined())
continue;
-
+
Constant *Const = IV.isConstant()
? IV.getConstant() : UndefValue::get(Inst->getType());
DEBUG(dbgs() << " Constant: " << *Const << " = " << *Inst);
@@ -1838,7 +1835,7 @@
// Replaces all of the uses of a variable with uses of the
// constant.
Inst->replaceAllUsesWith(Const);
-
+
// Delete the instruction.
if (!isa<CallInst>(Inst) && !isa<TerminatorInst>(Inst))
Inst->eraseFromParent();
@@ -1880,15 +1877,15 @@
llvm_unreachable("Didn't fold away reference to block!");
}
#endif
-
+
// Make this an uncond branch to the first successor.
TerminatorInst *TI = I->getParent()->getTerminator();
BranchInst::Create(TI->getSuccessor(0), TI);
-
+
// Remove entries in successor phi nodes to remove edges.
for (unsigned i = 1, e = TI->getNumSuccessors(); i != e; ++i)
TI->getSuccessor(i)->removePredecessor(TI->getParent());
-
+
// Remove the old terminator.
TI->eraseFromParent();
}
@@ -1911,7 +1908,7 @@
// last use of a function, the order of processing functions would affect
// whether other functions are optimizable.
SmallVector<ReturnInst*, 8> ReturnsToZap;
-
+
// TODO: Process multiple value ret instructions also.
const DenseMap<Function*, LatticeVal> &RV = Solver.getTrackedRetVals();
for (DenseMap<Function*, LatticeVal>::const_iterator I = RV.begin(),
@@ -1919,11 +1916,11 @@
Function *F = I->first;
if (I->second.isOverdefined() || F->getReturnType()->isVoidTy())
continue;
-
+
// We can only do this if we know that nothing else can call the function.
if (!F->hasLocalLinkage() || AddressTakenFunctions.count(F))
continue;
-
+
for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator()))
if (!isa<UndefValue>(RI->getOperand(0)))
@@ -1935,7 +1932,7 @@
Function *F = ReturnsToZap[i]->getParent()->getParent();
ReturnsToZap[i]->setOperand(0, UndefValue::get(F->getReturnType()));
}
-
+
// If we inferred constant or undef values for globals variables, we can delete
// the global and any stores that remain to it.
const DenseMap<GlobalVariable*, LatticeVal> &TG = Solver.getTrackedGlobals();
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