Expand GEPs in ScalarEvolution expressions. SCEV expressions can now
have pointer types, though in contrast to C pointer types, SCEV
addition is never implicitly scaled. This not only eliminates the
need for special code like IndVars' EliminatePointerRecurrence
and LSR's own GEP expansion code, it also does a better job because
it lets the normal optimizations handle pointer expressions just
like integer expressions.
Also, since LLVM IR GEPs can't directly index into multi-dimensional
VLAs, moving the GEP analysis out of client code and into the SCEV
framework makes it easier for clients to handle multi-dimensional
VLAs the same way as other arrays.
Some existing regression tests show improved optimization.
test/CodeGen/ARM/2007-03-13-InstrSched.ll in particular improved to
the point where if-conversion started kicking in; I turned it off
for this test to preserve the intent of the test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69258 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index c979613..01c9574 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -50,6 +50,7 @@
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
+#include "llvm/Target/TargetData.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/ADT/SmallVector.h"
@@ -59,7 +60,6 @@
using namespace llvm;
STATISTIC(NumRemoved , "Number of aux indvars removed");
-STATISTIC(NumPointer , "Number of pointer indvars promoted");
STATISTIC(NumInserted, "Number of canonical indvars added");
STATISTIC(NumReplaced, "Number of exit values replaced");
STATISTIC(NumLFTR , "Number of loop exit tests replaced");
@@ -67,6 +67,7 @@
namespace {
class VISIBILITY_HIDDEN IndVarSimplify : public LoopPass {
LoopInfo *LI;
+ TargetData *TD;
ScalarEvolution *SE;
bool Changed;
public:
@@ -81,6 +82,7 @@
AU.addRequiredID(LCSSAID);
AU.addRequiredID(LoopSimplifyID);
AU.addRequired<LoopInfo>();
+ AU.addRequired<TargetData>();
AU.addPreserved<ScalarEvolution>();
AU.addPreservedID(LoopSimplifyID);
AU.addPreservedID(LCSSAID);
@@ -91,8 +93,6 @@
void RewriteNonIntegerIVs(Loop *L);
- void EliminatePointerRecurrence(PHINode *PN, BasicBlock *Preheader,
- SmallPtrSet<Instruction*, 16> &DeadInsts);
void LinearFunctionTestReplace(Loop *L, SCEVHandle BackedgeTakenCount,
Value *IndVar,
BasicBlock *ExitingBlock,
@@ -135,97 +135,6 @@
}
}
-
-/// EliminatePointerRecurrence - Check to see if this is a trivial GEP pointer
-/// recurrence. If so, change it into an integer recurrence, permitting
-/// analysis by the SCEV routines.
-void IndVarSimplify::EliminatePointerRecurrence(PHINode *PN,
- BasicBlock *Preheader,
- SmallPtrSet<Instruction*, 16> &DeadInsts) {
- assert(PN->getNumIncomingValues() == 2 && "Noncanonicalized loop!");
- unsigned PreheaderIdx = PN->getBasicBlockIndex(Preheader);
- unsigned BackedgeIdx = PreheaderIdx^1;
- if (GetElementPtrInst *GEPI =
- dyn_cast<GetElementPtrInst>(PN->getIncomingValue(BackedgeIdx)))
- if (GEPI->getOperand(0) == PN) {
- assert(GEPI->getNumOperands() == 2 && "GEP types must match!");
- DOUT << "INDVARS: Eliminating pointer recurrence: " << *GEPI;
-
- // Okay, we found a pointer recurrence. Transform this pointer
- // recurrence into an integer recurrence. Compute the value that gets
- // added to the pointer at every iteration.
- Value *AddedVal = GEPI->getOperand(1);
-
- // Insert a new integer PHI node into the top of the block.
- PHINode *NewPhi = PHINode::Create(AddedVal->getType(),
- PN->getName()+".rec", PN);
- NewPhi->addIncoming(Constant::getNullValue(NewPhi->getType()), Preheader);
-
- // Create the new add instruction.
- Value *NewAdd = BinaryOperator::CreateAdd(NewPhi, AddedVal,
- GEPI->getName()+".rec", GEPI);
- NewPhi->addIncoming(NewAdd, PN->getIncomingBlock(BackedgeIdx));
-
- // Update the existing GEP to use the recurrence.
- GEPI->setOperand(0, PN->getIncomingValue(PreheaderIdx));
-
- // Update the GEP to use the new recurrence we just inserted.
- GEPI->setOperand(1, NewAdd);
-
- // If the incoming value is a constant expr GEP, try peeling out the array
- // 0 index if possible to make things simpler.
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(GEPI->getOperand(0)))
- if (CE->getOpcode() == Instruction::GetElementPtr) {
- unsigned NumOps = CE->getNumOperands();
- assert(NumOps > 1 && "CE folding didn't work!");
- if (CE->getOperand(NumOps-1)->isNullValue()) {
- // Check to make sure the last index really is an array index.
- gep_type_iterator GTI = gep_type_begin(CE);
- for (unsigned i = 1, e = CE->getNumOperands()-1;
- i != e; ++i, ++GTI)
- /*empty*/;
- if (isa<SequentialType>(*GTI)) {
- // Pull the last index out of the constant expr GEP.
- SmallVector<Value*, 8> CEIdxs(CE->op_begin()+1, CE->op_end()-1);
- Constant *NCE = ConstantExpr::getGetElementPtr(CE->getOperand(0),
- &CEIdxs[0],
- CEIdxs.size());
- Value *Idx[2];
- Idx[0] = Constant::getNullValue(Type::Int32Ty);
- Idx[1] = NewAdd;
- GetElementPtrInst *NGEPI = GetElementPtrInst::Create(
- NCE, Idx, Idx + 2,
- GEPI->getName(), GEPI);
- SE->deleteValueFromRecords(GEPI);
- GEPI->replaceAllUsesWith(NGEPI);
- GEPI->eraseFromParent();
- GEPI = NGEPI;
- }
- }
- }
-
-
- // Finally, if there are any other users of the PHI node, we must
- // insert a new GEP instruction that uses the pre-incremented version
- // of the induction amount.
- if (!PN->use_empty()) {
- BasicBlock::iterator InsertPos = PN; ++InsertPos;
- while (isa<PHINode>(InsertPos)) ++InsertPos;
- Value *PreInc =
- GetElementPtrInst::Create(PN->getIncomingValue(PreheaderIdx),
- NewPhi, "", InsertPos);
- PreInc->takeName(PN);
- PN->replaceAllUsesWith(PreInc);
- }
-
- // Delete the old PHI for sure, and the GEP if its otherwise unused.
- DeadInsts.insert(PN);
-
- ++NumPointer;
- Changed = true;
- }
-}
-
/// LinearFunctionTestReplace - This method rewrites the exit condition of the
/// loop to be a canonical != comparison against the incremented loop induction
/// variable. This pass is able to rewrite the exit tests of any loop where the
@@ -275,7 +184,7 @@
// Expand the code for the iteration count into the preheader of the loop.
BasicBlock *Preheader = L->getLoopPreheader();
- Value *ExitCnt = Rewriter.expandCodeFor(RHS,
+ Value *ExitCnt = Rewriter.expandCodeFor(RHS, IndVar->getType(),
Preheader->getTerminator());
// Insert a new icmp_ne or icmp_eq instruction before the branch.
@@ -307,7 +216,7 @@
// Scan all of the instructions in the loop, looking at those that have
// extra-loop users and which are recurrences.
- SCEVExpander Rewriter(*SE, *LI);
+ SCEVExpander Rewriter(*SE, *LI, *TD);
// We insert the code into the preheader of the loop if the loop contains
// multiple exit blocks, or in the exit block if there is exactly one.
@@ -349,7 +258,8 @@
Value *InVal = PN->getIncomingValue(i);
if (!isa<Instruction>(InVal) ||
// SCEV only supports integer expressions for now.
- !isa<IntegerType>(InVal->getType()))
+ (!isa<IntegerType>(InVal->getType()) &&
+ !isa<PointerType>(InVal->getType())))
continue;
// If this pred is for a subloop, not L itself, skip it.
@@ -384,7 +294,7 @@
// just reuse it.
Value *&ExitVal = ExitValues[Inst];
if (!ExitVal)
- ExitVal = Rewriter.expandCodeFor(ExitValue, InsertPt);
+ ExitVal = Rewriter.expandCodeFor(ExitValue, PN->getType(), InsertPt);
DOUT << "INDVARS: RLEV: AfterLoopVal = " << *ExitVal
<< " LoopVal = " << *Inst << "\n";
@@ -413,23 +323,19 @@
}
void IndVarSimplify::RewriteNonIntegerIVs(Loop *L) {
- // First step. Check to see if there are any trivial GEP pointer recurrences.
+ // First step. Check to see if there are any floating-point recurrences.
// If there are, change them into integer recurrences, permitting analysis by
// the SCEV routines.
//
BasicBlock *Header = L->getHeader();
- BasicBlock *Preheader = L->getLoopPreheader();
SmallPtrSet<Instruction*, 16> DeadInsts;
for (BasicBlock::iterator I = Header->begin(); isa<PHINode>(I); ++I) {
PHINode *PN = cast<PHINode>(I);
- if (isa<PointerType>(PN->getType()))
- EliminatePointerRecurrence(PN, Preheader, DeadInsts);
- else
- HandleFloatingPointIV(L, PN, DeadInsts);
+ HandleFloatingPointIV(L, PN, DeadInsts);
}
- // If the loop previously had a pointer or floating-point IV, ScalarEvolution
+ // If the loop previously had floating-point IV, ScalarEvolution
// may not have been able to compute a trip count. Now that we've done some
// re-writing, the trip count may be computable.
if (Changed)
@@ -442,7 +348,8 @@
/// getEffectiveIndvarType - Determine the widest type that the
/// induction-variable PHINode Phi is cast to.
///
-static const Type *getEffectiveIndvarType(const PHINode *Phi) {
+static const Type *getEffectiveIndvarType(const PHINode *Phi,
+ const TargetData *TD) {
const Type *Ty = Phi->getType();
for (Value::use_const_iterator UI = Phi->use_begin(), UE = Phi->use_end();
@@ -453,8 +360,7 @@
else if (const SExtInst *SI = dyn_cast<SExtInst>(UI))
CandidateType = SI->getDestTy();
if (CandidateType &&
- CandidateType->getPrimitiveSizeInBits() >
- Ty->getPrimitiveSizeInBits())
+ TD->getTypeSizeInBits(CandidateType) > TD->getTypeSizeInBits(Ty))
Ty = CandidateType;
}
@@ -482,6 +388,7 @@
static const PHINode *TestOrigIVForWrap(const Loop *L,
const BranchInst *BI,
const Instruction *OrigCond,
+ const TargetData *TD,
bool &NoSignedWrap,
bool &NoUnsignedWrap,
const ConstantInt* &InitialVal,
@@ -554,7 +461,7 @@
if (const SExtInst *SI = dyn_cast<SExtInst>(CmpLHS)) {
if (!isa<ConstantInt>(CmpRHS) ||
!cast<ConstantInt>(CmpRHS)->getValue()
- .isSignedIntN(IncrInst->getType()->getPrimitiveSizeInBits()))
+ .isSignedIntN(TD->getTypeSizeInBits(IncrInst->getType())))
return 0;
IncrInst = SI->getOperand(0);
}
@@ -562,7 +469,7 @@
if (const ZExtInst *ZI = dyn_cast<ZExtInst>(CmpLHS)) {
if (!isa<ConstantInt>(CmpRHS) ||
!cast<ConstantInt>(CmpRHS)->getValue()
- .isIntN(IncrInst->getType()->getPrimitiveSizeInBits()))
+ .isIntN(TD->getTypeSizeInBits(IncrInst->getType())))
return 0;
IncrInst = ZI->getOperand(0);
}
@@ -643,7 +550,7 @@
SE->getAddRecExpr(ExtendedStart, ExtendedStep, L);
if (LargestType != myType)
ExtendedAddRec = SE->getTruncateExpr(ExtendedAddRec, myType);
- return Rewriter.expandCodeFor(ExtendedAddRec, InsertPt);
+ return Rewriter.expandCodeFor(ExtendedAddRec, myType, InsertPt);
}
static Value *getZeroExtendedTruncVar(const SCEVAddRecExpr *AR,
@@ -660,7 +567,7 @@
SE->getAddRecExpr(ExtendedStart, ExtendedStep, L);
if (LargestType != myType)
ExtendedAddRec = SE->getTruncateExpr(ExtendedAddRec, myType);
- return Rewriter.expandCodeFor(ExtendedAddRec, InsertPt);
+ return Rewriter.expandCodeFor(ExtendedAddRec, myType, InsertPt);
}
/// allUsesAreSameTyped - See whether all Uses of I are instructions
@@ -682,10 +589,11 @@
bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
LI = &getAnalysis<LoopInfo>();
+ TD = &getAnalysis<TargetData>();
SE = &getAnalysis<ScalarEvolution>();
Changed = false;
- // If there are any floating-point or pointer recurrences, attempt to
+ // If there are any floating-point recurrences, attempt to
// transform them to use integer recurrences.
RewriteNonIntegerIVs(L);
@@ -712,7 +620,7 @@
for (BasicBlock::iterator I = Header->begin(); isa<PHINode>(I); ++I) {
PHINode *PN = cast<PHINode>(I);
- if (PN->getType()->isInteger()) { // FIXME: when we have fast-math, enable!
+ if (PN->getType()->isInteger() || isa<PointerType>(PN->getType())) {
SCEVHandle SCEV = SE->getSCEV(PN);
// FIXME: It is an extremely bad idea to indvar substitute anything more
// complex than affine induction variables. Doing so will put expensive
@@ -731,21 +639,26 @@
SmallSetVector<const Type *, 4> SizesToInsert;
if (!isa<SCEVCouldNotCompute>(BackedgeTakenCount)) {
LargestType = BackedgeTakenCount->getType();
- SizesToInsert.insert(BackedgeTakenCount->getType());
+ if (isa<PointerType>(LargestType))
+ LargestType = TD->getIntPtrType();
+ SizesToInsert.insert(LargestType);
}
for (unsigned i = 0, e = IndVars.size(); i != e; ++i) {
const PHINode *PN = IndVars[i].first;
- SizesToInsert.insert(PN->getType());
- const Type *EffTy = getEffectiveIndvarType(PN);
+ const Type *PNTy = PN->getType();
+ if (isa<PointerType>(PNTy)) PNTy = TD->getIntPtrType();
+ SizesToInsert.insert(PNTy);
+ const Type *EffTy = getEffectiveIndvarType(PN, TD);
+ if (isa<PointerType>(EffTy)) EffTy = TD->getIntPtrType();
SizesToInsert.insert(EffTy);
if (!LargestType ||
- EffTy->getPrimitiveSizeInBits() >
- LargestType->getPrimitiveSizeInBits())
+ TD->getTypeSizeInBits(EffTy) >
+ TD->getTypeSizeInBits(LargestType))
LargestType = EffTy;
}
// Create a rewriter object which we'll use to transform the code with.
- SCEVExpander Rewriter(*SE, *LI);
+ SCEVExpander Rewriter(*SE, *LI, *TD);
// Now that we know the largest of of the induction variables in this loop,
// insert a canonical induction variable of the largest size.
@@ -769,7 +682,7 @@
if (Instruction *OrigCond = dyn_cast<Instruction>(BI->getCondition())) {
// Determine if the OrigIV will ever undergo overflow.
OrigControllingPHI =
- TestOrigIVForWrap(L, BI, OrigCond,
+ TestOrigIVForWrap(L, BI, OrigCond, TD,
NoSignedWrap, NoUnsignedWrap,
InitialVal, IncrVal, LimitVal);
@@ -804,7 +717,7 @@
while (!IndVars.empty()) {
PHINode *PN = IndVars.back().first;
SCEVAddRecExpr *AR = cast<SCEVAddRecExpr>(IndVars.back().second);
- Value *NewVal = Rewriter.expandCodeFor(AR, InsertPt);
+ Value *NewVal = Rewriter.expandCodeFor(AR, PN->getType(), InsertPt);
DOUT << "INDVARS: Rewrote IV '" << *AR << "' " << *PN
<< " into = " << *NewVal << "\n";
NewVal->takeName(PN);
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 6401a4c..a542ca0 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -1,4 +1,4 @@
-//===- LoopStrengthReduce.cpp - Strength Reduce GEPs in Loops -------------===//
+//===- LoopStrengthReduce.cpp - Strength Reduce IVs in Loops --------------===//
//
// The LLVM Compiler Infrastructure
//
@@ -8,10 +8,7 @@
//===----------------------------------------------------------------------===//
//
// This pass performs a strength reduction on array references inside loops that
-// have as one or more of their components the loop induction variable. This is
-// accomplished by creating a new Value to hold the initial value of the array
-// access for the first iteration, and then creating a new GEP instruction in
-// the loop to increment the value by the appropriate amount.
+// have as one or more of their components the loop induction variable.
//
//===----------------------------------------------------------------------===//
@@ -133,17 +130,6 @@
/// dependent on random ordering of pointers in the process.
SmallVector<SCEVHandle, 16> StrideOrder;
- /// GEPlist - A list of the GEP's that have been remembered in the SCEV
- /// data structures. SCEV does not know to update these when the operands
- /// of the GEP are changed, which means we cannot leave them live across
- /// loops.
- SmallVector<GetElementPtrInst *, 16> GEPlist;
-
- /// CastedValues - As we need to cast values to uintptr_t, this keeps track
- /// of the casted version of each value. This is accessed by
- /// getCastedVersionOf.
- DenseMap<Value*, Value*> CastedPointers;
-
/// DeadInsts - Keep track of instructions we may have made dead, so that
/// we can remove them after we are done working.
SmallVector<Instruction*, 16> DeadInsts;
@@ -175,14 +161,10 @@
AU.addRequired<ScalarEvolution>();
AU.addPreserved<ScalarEvolution>();
}
-
- /// getCastedVersionOf - Return the specified value casted to uintptr_t.
- ///
- Value *getCastedVersionOf(Instruction::CastOps opcode, Value *V);
+
private:
bool AddUsersIfInteresting(Instruction *I, Loop *L,
SmallPtrSet<Instruction*,16> &Processed);
- SCEVHandle GetExpressionSCEV(Instruction *E);
ICmpInst *ChangeCompareStride(Loop *L, ICmpInst *Cond,
IVStrideUse* &CondUse,
const SCEVHandle* &CondStride);
@@ -249,24 +231,6 @@
return new LoopStrengthReduce(TLI);
}
-/// getCastedVersionOf - Return the specified value casted to uintptr_t. This
-/// assumes that the Value* V is of integer or pointer type only.
-///
-Value *LoopStrengthReduce::getCastedVersionOf(Instruction::CastOps opcode,
- Value *V) {
- if (V->getType() == UIntPtrTy) return V;
- if (Constant *CB = dyn_cast<Constant>(V))
- return ConstantExpr::getCast(opcode, CB, UIntPtrTy);
-
- Value *&New = CastedPointers[V];
- if (New) return New;
-
- New = SCEVExpander::InsertCastOfTo(opcode, V, UIntPtrTy);
- DeadInsts.push_back(cast<Instruction>(New));
- return New;
-}
-
-
/// DeleteTriviallyDeadInstructions - If any of the instructions is the
/// specified set are trivially dead, delete them and see if this makes any of
/// their operands subsequently dead.
@@ -308,74 +272,6 @@
}
}
-
-/// GetExpressionSCEV - Compute and return the SCEV for the specified
-/// instruction.
-SCEVHandle LoopStrengthReduce::GetExpressionSCEV(Instruction *Exp) {
- // Pointer to pointer bitcast instructions return the same value as their
- // operand.
- if (BitCastInst *BCI = dyn_cast<BitCastInst>(Exp)) {
- if (SE->hasSCEV(BCI) || !isa<Instruction>(BCI->getOperand(0)))
- return SE->getSCEV(BCI);
- SCEVHandle R = GetExpressionSCEV(cast<Instruction>(BCI->getOperand(0)));
- SE->setSCEV(BCI, R);
- return R;
- }
-
- // Scalar Evolutions doesn't know how to compute SCEV's for GEP instructions.
- // If this is a GEP that SE doesn't know about, compute it now and insert it.
- // If this is not a GEP, or if we have already done this computation, just let
- // SE figure it out.
- GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Exp);
- if (!GEP || SE->hasSCEV(GEP))
- return SE->getSCEV(Exp);
-
- // Analyze all of the subscripts of this getelementptr instruction, looking
- // for uses that are determined by the trip count of the loop. First, skip
- // all operands the are not dependent on the IV.
-
- // Build up the base expression. Insert an LLVM cast of the pointer to
- // uintptr_t first.
- SCEVHandle GEPVal = SE->getUnknown(
- getCastedVersionOf(Instruction::PtrToInt, GEP->getOperand(0)));
-
- gep_type_iterator GTI = gep_type_begin(GEP);
-
- for (User::op_iterator i = GEP->op_begin() + 1, e = GEP->op_end();
- i != e; ++i, ++GTI) {
- // If this is a use of a recurrence that we can analyze, and it comes before
- // Op does in the GEP operand list, we will handle this when we process this
- // operand.
- if (const StructType *STy = dyn_cast<StructType>(*GTI)) {
- const StructLayout *SL = TD->getStructLayout(STy);
- unsigned Idx = cast<ConstantInt>(*i)->getZExtValue();
- uint64_t Offset = SL->getElementOffset(Idx);
- GEPVal = SE->getAddExpr(GEPVal,
- SE->getIntegerSCEV(Offset, UIntPtrTy));
- } else {
- unsigned GEPOpiBits =
- (*i)->getType()->getPrimitiveSizeInBits();
- unsigned IntPtrBits = UIntPtrTy->getPrimitiveSizeInBits();
- Instruction::CastOps opcode = (GEPOpiBits < IntPtrBits ?
- Instruction::SExt : (GEPOpiBits > IntPtrBits ? Instruction::Trunc :
- Instruction::BitCast));
- Value *OpVal = getCastedVersionOf(opcode, *i);
- SCEVHandle Idx = SE->getSCEV(OpVal);
-
- uint64_t TypeSize = TD->getTypePaddedSize(GTI.getIndexedType());
- if (TypeSize != 1)
- Idx = SE->getMulExpr(Idx,
- SE->getConstant(ConstantInt::get(UIntPtrTy,
- TypeSize)));
- GEPVal = SE->getAddExpr(GEPVal, Idx);
- }
- }
-
- SE->setSCEV(GEP, GEPVal);
- GEPlist.push_back(GEP);
- return GEPVal;
-}
-
/// containsAddRecFromDifferentLoop - Determine whether expression S involves a
/// subexpression that is an AddRec from a loop other than L. An outer loop
/// of L is OK, but not an inner loop nor a disjoint loop.
@@ -602,7 +498,7 @@
return true; // Instruction already handled.
// Get the symbolic expression for this instruction.
- SCEVHandle ISE = GetExpressionSCEV(I);
+ SCEVHandle ISE = SE->getSCEV(I);
if (isa<SCEVCouldNotCompute>(ISE)) return false;
// Get the start and stride for this expression.
@@ -722,6 +618,7 @@
SmallVectorImpl<Instruction*> &DeadInsts);
Value *InsertCodeForBaseAtPosition(const SCEVHandle &NewBase,
+ const Type *Ty,
SCEVExpander &Rewriter,
Instruction *IP, Loop *L);
void dump() const;
@@ -735,6 +632,7 @@
}
Value *BasedUser::InsertCodeForBaseAtPosition(const SCEVHandle &NewBase,
+ const Type *Ty,
SCEVExpander &Rewriter,
Instruction *IP, Loop *L) {
// Figure out where we *really* want to insert this code. In particular, if
@@ -755,7 +653,7 @@
InsertLoop = InsertLoop->getParentLoop();
}
- Value *Base = Rewriter.expandCodeFor(NewBase, BaseInsertPt);
+ Value *Base = Rewriter.expandCodeFor(NewBase, Ty, BaseInsertPt);
// If there is no immediate value, skip the next part.
if (Imm->isZero())
@@ -768,8 +666,7 @@
// Always emit the immediate (if non-zero) into the same block as the user.
SCEVHandle NewValSCEV = SE->getAddExpr(SE->getUnknown(Base), Imm);
- return Rewriter.expandCodeFor(NewValSCEV, IP);
-
+ return Rewriter.expandCodeFor(NewValSCEV, Ty, IP);
}
@@ -809,15 +706,9 @@
while (isa<PHINode>(InsertPt)) ++InsertPt;
}
}
- Value *NewVal = InsertCodeForBaseAtPosition(NewBase, Rewriter, InsertPt, L);
- // Adjust the type back to match the Inst. Note that we can't use InsertPt
- // here because the SCEVExpander may have inserted the instructions after
- // that point, in its efforts to avoid inserting redundant expressions.
- if (isa<PointerType>(OperandValToReplace->getType())) {
- NewVal = SCEVExpander::InsertCastOfTo(Instruction::IntToPtr,
- NewVal,
- OperandValToReplace->getType());
- }
+ Value *NewVal = InsertCodeForBaseAtPosition(NewBase,
+ OperandValToReplace->getType(),
+ Rewriter, InsertPt, L);
// Replace the use of the operand Value with the new Phi we just created.
Inst->replaceUsesOfWith(OperandValToReplace, NewVal);
@@ -875,17 +766,8 @@
Instruction *InsertPt = (L->contains(OldLoc->getParent())) ?
PN->getIncomingBlock(i)->getTerminator() :
OldLoc->getParent()->getTerminator();
- Code = InsertCodeForBaseAtPosition(NewBase, Rewriter, InsertPt, L);
-
- // Adjust the type back to match the PHI. Note that we can't use
- // InsertPt here because the SCEVExpander may have inserted its
- // instructions after that point, in its efforts to avoid inserting
- // redundant expressions.
- if (isa<PointerType>(PN->getType())) {
- Code = SCEVExpander::InsertCastOfTo(Instruction::IntToPtr,
- Code,
- PN->getType());
- }
+ Code = InsertCodeForBaseAtPosition(NewBase, PN->getType(),
+ Rewriter, InsertPt, L);
DOUT << " Changing PHI use to ";
DEBUG(WriteAsOperand(*DOUT, Code, /*PrintType=*/false));
@@ -921,16 +803,13 @@
}
if (SCEVUnknown *SU = dyn_cast<SCEVUnknown>(V))
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(SU->getValue()))
- if (TLI && CE->getOpcode() == Instruction::PtrToInt) {
- Constant *Op0 = CE->getOperand(0);
- if (GlobalValue *GV = dyn_cast<GlobalValue>(Op0)) {
- TargetLowering::AddrMode AM;
- AM.BaseGV = GV;
- AM.HasBaseReg = HasBaseReg;
- return TLI->isLegalAddressingMode(AM, UseTy);
- }
- }
+ if (GlobalValue *GV = dyn_cast<GlobalValue>(SU->getValue())) {
+ TargetLowering::AddrMode AM;
+ AM.BaseGV = GV;
+ AM.HasBaseReg = HasBaseReg;
+ return TLI->isLegalAddressingMode(AM, UseTy);
+ }
+
return false;
}
@@ -1591,6 +1470,7 @@
///
static PHINode *InsertAffinePhi(SCEVHandle Start, SCEVHandle Step,
const Loop *L,
+ const TargetData *TD,
SCEVExpander &Rewriter) {
assert(Start->isLoopInvariant(L) && "New PHI start is not loop invariant!");
assert(Step->isLoopInvariant(L) && "New PHI stride is not loop invariant!");
@@ -1598,9 +1478,11 @@
BasicBlock *Header = L->getHeader();
BasicBlock *Preheader = L->getLoopPreheader();
BasicBlock *LatchBlock = L->getLoopLatch();
+ const Type *Ty = Start->getType();
+ if (isa<PointerType>(Ty)) Ty = TD->getIntPtrType();
- PHINode *PN = PHINode::Create(Start->getType(), "lsr.iv", Header->begin());
- PN->addIncoming(Rewriter.expandCodeFor(Start, Preheader->getTerminator()),
+ PHINode *PN = PHINode::Create(Ty, "lsr.iv", Header->begin());
+ PN->addIncoming(Rewriter.expandCodeFor(Start, Ty, Preheader->getTerminator()),
Preheader);
// If the stride is negative, insert a sub instead of an add for the
@@ -1612,7 +1494,8 @@
// Insert an add instruction right before the terminator corresponding
// to the back-edge.
- Value *StepV = Rewriter.expandCodeFor(IncAmount, Preheader->getTerminator());
+ Value *StepV = Rewriter.expandCodeFor(IncAmount, Ty,
+ Preheader->getTerminator());
Instruction *IncV;
if (isNegative) {
IncV = BinaryOperator::CreateSub(PN, StepV, "lsr.iv.next",
@@ -1683,7 +1566,7 @@
SCEVHandle Imm = UsersToProcess[i].Imm;
SCEVHandle Base = UsersToProcess[i].Base;
SCEVHandle Start = SE->getAddExpr(CommonExprs, Base, Imm);
- PHINode *Phi = InsertAffinePhi(Start, Stride, L,
+ PHINode *Phi = InsertAffinePhi(Start, Stride, L, TD,
PreheaderRewriter);
// Loop over all the users with the same base.
do {
@@ -1710,7 +1593,7 @@
DOUT << " Inserting new PHI:\n";
PHINode *Phi = InsertAffinePhi(SE->getUnknown(CommonBaseV),
- Stride, L,
+ Stride, L, TD,
PreheaderRewriter);
// Remember this in case a later stride is multiple of this.
@@ -1816,6 +1699,7 @@
bool HaveCommonExprs = !CommonExprs->isZero();
const Type *ReplacedTy = CommonExprs->getType();
+ if (isa<PointerType>(ReplacedTy)) ReplacedTy = TD->getIntPtrType();
// If all uses are addresses, consider sinking the immediate part of the
// common expression back into uses if they can fit in the immediate fields.
@@ -1829,11 +1713,8 @@
// If the immediate part of the common expression is a GV, check if it's
// possible to fold it into the target addressing mode.
GlobalValue *GV = 0;
- if (SCEVUnknown *SU = dyn_cast<SCEVUnknown>(Imm)) {
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(SU->getValue()))
- if (CE->getOpcode() == Instruction::PtrToInt)
- GV = dyn_cast<GlobalValue>(CE->getOperand(0));
- }
+ if (SCEVUnknown *SU = dyn_cast<SCEVUnknown>(Imm))
+ GV = dyn_cast<GlobalValue>(SU->getValue());
int64_t Offset = 0;
if (SCEVConstant *SC = dyn_cast<SCEVConstant>(Imm))
Offset = SC->getValue()->getSExtValue();
@@ -1860,8 +1741,8 @@
<< *Stride << ":\n"
<< " Common base: " << *CommonExprs << "\n";
- SCEVExpander Rewriter(*SE, *LI);
- SCEVExpander PreheaderRewriter(*SE, *LI);
+ SCEVExpander Rewriter(*SE, *LI, *TD);
+ SCEVExpander PreheaderRewriter(*SE, *LI, *TD);
BasicBlock *Preheader = L->getLoopPreheader();
Instruction *PreInsertPt = Preheader->getTerminator();
@@ -1882,7 +1763,8 @@
PreheaderRewriter);
} else {
// Emit the initial base value into the loop preheader.
- CommonBaseV = PreheaderRewriter.expandCodeFor(CommonExprs, PreInsertPt);
+ CommonBaseV = PreheaderRewriter.expandCodeFor(CommonExprs, ReplacedTy,
+ PreInsertPt);
// If all uses are addresses, check if it is possible to reuse an IV with a
// stride that is a factor of this stride. And that the multiple is a number
@@ -1910,19 +1792,21 @@
Instruction *Inst = UsersToProcess.back().Inst;
// Emit the code for Base into the preheader.
- Value *BaseV = PreheaderRewriter.expandCodeFor(Base, PreInsertPt);
+ Value *BaseV = 0;
+ if (!Base->isZero()) {
+ BaseV = PreheaderRewriter.expandCodeFor(Base, Base->getType(),
+ PreInsertPt);
- DOUT << " Examining uses with BASE ";
- DEBUG(WriteAsOperand(*DOUT, BaseV, /*PrintType=*/false));
- DOUT << ":\n";
+ DOUT << " INSERTING code for BASE = " << *Base << ":";
+ if (BaseV->hasName())
+ DOUT << " Result value name = %" << BaseV->getNameStr();
+ DOUT << "\n";
- // If BaseV is a constant other than 0, make sure that it gets inserted into
- // the preheader, instead of being forward substituted into the uses. We do
- // this by forcing a BitCast (noop cast) to be inserted into the preheader
- // in this case.
- if (Constant *C = dyn_cast<Constant>(BaseV)) {
- if (!C->isNullValue() && !fitsInAddressMode(Base, getAccessType(Inst),
- TLI, false)) {
+ // If BaseV is a non-zero constant, make sure that it gets inserted into
+ // the preheader, instead of being forward substituted into the uses. We
+ // do this by forcing a BitCast (noop cast) to be inserted into the
+ // preheader in this case.
+ if (!fitsInAddressMode(Base, getAccessType(Inst), TLI, false)) {
// We want this constant emitted into the preheader! This is just
// using cast as a copy so BitCast (no-op cast) is appropriate
BaseV = new BitCastInst(BaseV, BaseV->getType(), "preheaderinsert",
@@ -1953,10 +1837,11 @@
User.Inst->moveBefore(LatchBlock->getTerminator());
}
if (RewriteOp->getType() != ReplacedTy) {
- Instruction::CastOps opcode = Instruction::Trunc;
- if (ReplacedTy->getPrimitiveSizeInBits() ==
- RewriteOp->getType()->getPrimitiveSizeInBits())
- opcode = Instruction::BitCast;
+ Instruction::CastOps opcode =
+ CastInst::getCastOpcode(RewriteOp, false, ReplacedTy, false);
+ assert(opcode != Instruction::SExt &&
+ opcode != Instruction::ZExt &&
+ "Unexpected widening cast!");
RewriteOp = SCEVExpander::InsertCastOfTo(opcode, RewriteOp, ReplacedTy);
}
@@ -1978,8 +1863,7 @@
// If we are reusing the iv, then it must be multiplied by a constant
// factor to take advantage of the addressing mode scale component.
- if (!isa<SCEVConstant>(RewriteFactor) ||
- !cast<SCEVConstant>(RewriteFactor)->isZero()) {
+ if (!RewriteFactor->isZero()) {
// If we're reusing an IV with a nonzero base (currently this happens
// only when all reuses are outside the loop) subtract that base here.
// The base has been used to initialize the PHI node but we don't want
@@ -2010,8 +1894,7 @@
// When this use is outside the loop, we earlier subtracted the
// common base, and are adding it back here. Use the same expression
// as before, rather than CommonBaseV, so DAGCombiner will zap it.
- if (!isa<ConstantInt>(CommonBaseV) ||
- !cast<ConstantInt>(CommonBaseV)->isZero()) {
+ if (!CommonExprs->isZero()) {
if (L->contains(User.Inst->getParent()))
RewriteExpr = SE->getAddExpr(RewriteExpr,
SE->getUnknown(CommonBaseV));
@@ -2022,7 +1905,7 @@
// Now that we know what we need to do, insert code before User for the
// immediate and any loop-variant expressions.
- if (!isa<ConstantInt>(BaseV) || !cast<ConstantInt>(BaseV)->isZero())
+ if (BaseV)
// Add BaseV to the PHI value if needed.
RewriteExpr = SE->getAddExpr(RewriteExpr, SE->getUnknown(BaseV));
@@ -2078,6 +1961,9 @@
// e.g.
// 4, -1, X, 1, 2 ==> 1, -1, 2, 4, X
struct StrideCompare {
+ const TargetData *TD;
+ explicit StrideCompare(const TargetData *td) : TD(td) {}
+
bool operator()(const SCEVHandle &LHS, const SCEVHandle &RHS) {
SCEVConstant *LHSC = dyn_cast<SCEVConstant>(LHS);
SCEVConstant *RHSC = dyn_cast<SCEVConstant>(RHS);
@@ -2096,7 +1982,8 @@
// If it's the same value but different type, sort by bit width so
// that we emit larger induction variables before smaller
// ones, letting the smaller be re-written in terms of larger ones.
- return RHS->getBitWidth() < LHS->getBitWidth();
+ return TD->getTypeSizeInBits(RHS->getType()) <
+ TD->getTypeSizeInBits(LHS->getType());
}
return LHSC && !RHSC;
}
@@ -2129,11 +2016,11 @@
ICmpInst::Predicate Predicate = Cond->getPredicate();
int64_t CmpSSInt = SC->getValue()->getSExtValue();
- unsigned BitWidth = (*CondStride)->getBitWidth();
+ unsigned BitWidth = TD->getTypeSizeInBits((*CondStride)->getType());
uint64_t SignBit = 1ULL << (BitWidth-1);
const Type *CmpTy = Cond->getOperand(0)->getType();
const Type *NewCmpTy = NULL;
- unsigned TyBits = CmpTy->getPrimitiveSizeInBits();
+ unsigned TyBits = TD->getTypeSizeInBits(CmpTy);
unsigned NewTyBits = 0;
SCEVHandle *NewStride = NULL;
Value *NewCmpLHS = NULL;
@@ -2185,9 +2072,7 @@
continue;
NewCmpTy = NewCmpLHS->getType();
- NewTyBits = isa<PointerType>(NewCmpTy)
- ? UIntPtrTy->getPrimitiveSizeInBits()
- : NewCmpTy->getPrimitiveSizeInBits();
+ NewTyBits = TD->getTypeSizeInBits(NewCmpTy);
if (RequiresTypeConversion(NewCmpTy, CmpTy)) {
// Check if it is possible to rewrite it using
// an iv / stride of a smaller integer type.
@@ -2604,7 +2489,7 @@
#endif
// Sort the StrideOrder so we process larger strides first.
- std::stable_sort(StrideOrder.begin(), StrideOrder.end(), StrideCompare());
+ std::stable_sort(StrideOrder.begin(), StrideOrder.end(), StrideCompare(TD));
// Optimize induction variables. Some indvar uses can be transformed to use
// strides that will be needed for other purposes. A common example of this
@@ -2638,13 +2523,9 @@
}
// We're done analyzing this loop; release all the state we built up for it.
- CastedPointers.clear();
IVUsesByStride.clear();
IVsByStride.clear();
StrideOrder.clear();
- for (unsigned i=0; i<GEPlist.size(); i++)
- SE->deleteValueFromRecords(GEPlist[i]);
- GEPlist.clear();
// Clean up after ourselves
if (!DeadInsts.empty()) {