[llvm-commits] [llvm] r49419 - in /llvm/trunk: include/llvm/ include/llvm/Transforms/ lib/Transforms/Scalar/ test/Transforms/GVN/ test/Transforms/MemCpyOpt/ tools/llvm-ld/ tools/opt/
Owen Anderson
resistor at mac.com
Wed Apr 9 01:23:16 PDT 2008
Author: resistor
Date: Wed Apr 9 03:23:16 2008
New Revision: 49419
URL: http://llvm.org/viewvc/llvm-project?rev=49419&view=rev
Log:
Factor a bunch of functionality related to memcpy and memset transforms out of
GVN and into its own pass.
Added:
llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
llvm/trunk/test/Transforms/MemCpyOpt/
llvm/trunk/test/Transforms/MemCpyOpt/2008-02-24-MultipleUseofSRet.ll
- copied, changed from r49415, llvm/trunk/test/Transforms/GVN/2008-02-24-MultipleUseofSRet.ll
llvm/trunk/test/Transforms/MemCpyOpt/2008-03-13-ReturnSlotBitcast.ll
- copied, changed from r49415, llvm/trunk/test/Transforms/GVN/2008-03-13-ReturnSlotBitcast.ll
llvm/trunk/test/Transforms/MemCpyOpt/dg.exp
llvm/trunk/test/Transforms/MemCpyOpt/form-memset.ll
- copied, changed from r49415, llvm/trunk/test/Transforms/GVN/form-memset.ll
llvm/trunk/test/Transforms/MemCpyOpt/form-memset2.ll
- copied, changed from r49415, llvm/trunk/test/Transforms/GVN/form-memset2.ll
llvm/trunk/test/Transforms/MemCpyOpt/memcpy.ll
- copied, changed from r49415, llvm/trunk/test/Transforms/GVN/memcpy.ll
llvm/trunk/test/Transforms/MemCpyOpt/sret.ll
- copied, changed from r49415, llvm/trunk/test/Transforms/GVN/sret.ll
Removed:
llvm/trunk/test/Transforms/GVN/2008-02-24-MultipleUseofSRet.ll
llvm/trunk/test/Transforms/GVN/2008-03-13-ReturnSlotBitcast.ll
llvm/trunk/test/Transforms/GVN/form-memset.ll
llvm/trunk/test/Transforms/GVN/form-memset2.ll
llvm/trunk/test/Transforms/GVN/memcpy.ll
llvm/trunk/test/Transforms/GVN/sret.ll
Modified:
llvm/trunk/include/llvm/LinkAllPasses.h
llvm/trunk/include/llvm/Transforms/Scalar.h
llvm/trunk/lib/Transforms/Scalar/GVN.cpp
llvm/trunk/tools/llvm-ld/Optimize.cpp
llvm/trunk/tools/opt/opt.cpp
Modified: llvm/trunk/include/llvm/LinkAllPasses.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/LinkAllPasses.h?rev=49419&r1=49418&r2=49419&view=diff
==============================================================================
--- llvm/trunk/include/llvm/LinkAllPasses.h (original)
+++ llvm/trunk/include/llvm/LinkAllPasses.h Wed Apr 9 03:23:16 2008
@@ -112,6 +112,7 @@
(void) llvm::createPredicateSimplifierPass();
(void) llvm::createCodeGenPreparePass();
(void) llvm::createGVNPass();
+ (void) llvm::createMemCpyOptPass();
(void)new llvm::IntervalPartition();
(void)new llvm::FindUsedTypes();
Modified: llvm/trunk/include/llvm/Transforms/Scalar.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Scalar.h?rev=49419&r1=49418&r2=49419&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Scalar.h (original)
+++ llvm/trunk/include/llvm/Transforms/Scalar.h Wed Apr 9 03:23:16 2008
@@ -305,6 +305,13 @@
//===----------------------------------------------------------------------===//
//
+// MemCpyOpt - This pass performs optimizations related to eliminating memcpy
+// calls and/or combining multiple stores into memset's.
+//
+FunctionPass *createMemCpyOptPass();
+
+//===----------------------------------------------------------------------===//
+//
// CodeGenPrepare - This pass prepares a function for instruction selection.
//
FunctionPass *createCodeGenPreparePass(const TargetLowering *TLI = 0);
Modified: llvm/trunk/lib/Transforms/Scalar/GVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVN.cpp?rev=49419&r1=49418&r2=49419&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVN.cpp Wed Apr 9 03:23:16 2008
@@ -42,14 +42,6 @@
STATISTIC(NumGVNInstr, "Number of instructions deleted");
STATISTIC(NumGVNLoad, "Number of loads deleted");
-STATISTIC(NumMemSetInfer, "Number of memsets inferred");
-
-namespace {
- cl::opt<bool>
- FormMemSet("form-memset-from-stores",
- cl::desc("Transform straight-line stores to memsets"),
- cl::init(true), cl::Hidden);
-}
//===----------------------------------------------------------------------===//
// ValueTable Class
@@ -668,17 +660,12 @@
bool processLoad(LoadInst* L,
DenseMap<Value*, LoadInst*> &lastLoad,
SmallVectorImpl<Instruction*> &toErase);
- bool processStore(StoreInst *SI, SmallVectorImpl<Instruction*> &toErase);
bool processInstruction(Instruction* I,
ValueNumberedSet& currAvail,
DenseMap<Value*, LoadInst*>& lastSeenLoad,
SmallVectorImpl<Instruction*> &toErase);
bool processNonLocalLoad(LoadInst* L,
SmallVectorImpl<Instruction*> &toErase);
- bool processMemCpy(MemCpyInst* M, MemCpyInst* MDep,
- SmallVectorImpl<Instruction*> &toErase);
- bool performCallSlotOptzn(MemCpyInst* cpy, CallInst* C,
- SmallVectorImpl<Instruction*> &toErase);
Value *GetValueForBlock(BasicBlock *BB, LoadInst* orig,
DenseMap<BasicBlock*, Value*> &Phis,
bool top_level = false);
@@ -983,593 +970,6 @@
return deletedLoad;
}
-/// isBytewiseValue - If the specified value can be set by repeating the same
-/// byte in memory, return the i8 value that it is represented with. This is
-/// true for all i8 values obviously, but is also true for i32 0, i32 -1,
-/// i16 0xF0F0, double 0.0 etc. If the value can't be handled with a repeated
-/// byte store (e.g. i16 0x1234), return null.
-static Value *isBytewiseValue(Value *V) {
- // All byte-wide stores are splatable, even of arbitrary variables.
- if (V->getType() == Type::Int8Ty) return V;
-
- // Constant float and double values can be handled as integer values if the
- // corresponding integer value is "byteable". An important case is 0.0.
- if (ConstantFP *CFP = dyn_cast<ConstantFP>(V)) {
- if (CFP->getType() == Type::FloatTy)
- V = ConstantExpr::getBitCast(CFP, Type::Int32Ty);
- if (CFP->getType() == Type::DoubleTy)
- V = ConstantExpr::getBitCast(CFP, Type::Int64Ty);
- // Don't handle long double formats, which have strange constraints.
- }
-
- // We can handle constant integers that are power of two in size and a
- // multiple of 8 bits.
- if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
- unsigned Width = CI->getBitWidth();
- if (isPowerOf2_32(Width) && Width > 8) {
- // We can handle this value if the recursive binary decomposition is the
- // same at all levels.
- APInt Val = CI->getValue();
- APInt Val2;
- while (Val.getBitWidth() != 8) {
- unsigned NextWidth = Val.getBitWidth()/2;
- Val2 = Val.lshr(NextWidth);
- Val2.trunc(Val.getBitWidth()/2);
- Val.trunc(Val.getBitWidth()/2);
-
- // If the top/bottom halves aren't the same, reject it.
- if (Val != Val2)
- return 0;
- }
- return ConstantInt::get(Val);
- }
- }
-
- // Conceptually, we could handle things like:
- // %a = zext i8 %X to i16
- // %b = shl i16 %a, 8
- // %c = or i16 %a, %b
- // but until there is an example that actually needs this, it doesn't seem
- // worth worrying about.
- return 0;
-}
-
-static int64_t GetOffsetFromIndex(const GetElementPtrInst *GEP, unsigned Idx,
- bool &VariableIdxFound, TargetData &TD) {
- // Skip over the first indices.
- gep_type_iterator GTI = gep_type_begin(GEP);
- for (unsigned i = 1; i != Idx; ++i, ++GTI)
- /*skip along*/;
-
- // Compute the offset implied by the rest of the indices.
- int64_t Offset = 0;
- for (unsigned i = Idx, e = GEP->getNumOperands(); i != e; ++i, ++GTI) {
- ConstantInt *OpC = dyn_cast<ConstantInt>(GEP->getOperand(i));
- if (OpC == 0)
- return VariableIdxFound = true;
- if (OpC->isZero()) continue; // No offset.
-
- // Handle struct indices, which add their field offset to the pointer.
- if (const StructType *STy = dyn_cast<StructType>(*GTI)) {
- Offset += TD.getStructLayout(STy)->getElementOffset(OpC->getZExtValue());
- continue;
- }
-
- // Otherwise, we have a sequential type like an array or vector. Multiply
- // the index by the ElementSize.
- uint64_t Size = TD.getABITypeSize(GTI.getIndexedType());
- Offset += Size*OpC->getSExtValue();
- }
-
- return Offset;
-}
-
-/// IsPointerOffset - Return true if Ptr1 is provably equal to Ptr2 plus a
-/// constant offset, and return that constant offset. For example, Ptr1 might
-/// be &A[42], and Ptr2 might be &A[40]. In this case offset would be -8.
-static bool IsPointerOffset(Value *Ptr1, Value *Ptr2, int64_t &Offset,
- TargetData &TD) {
- // Right now we handle the case when Ptr1/Ptr2 are both GEPs with an identical
- // base. After that base, they may have some number of common (and
- // potentially variable) indices. After that they handle some constant
- // offset, which determines their offset from each other. At this point, we
- // handle no other case.
- GetElementPtrInst *GEP1 = dyn_cast<GetElementPtrInst>(Ptr1);
- GetElementPtrInst *GEP2 = dyn_cast<GetElementPtrInst>(Ptr2);
- if (!GEP1 || !GEP2 || GEP1->getOperand(0) != GEP2->getOperand(0))
- return false;
-
- // Skip any common indices and track the GEP types.
- unsigned Idx = 1;
- for (; Idx != GEP1->getNumOperands() && Idx != GEP2->getNumOperands(); ++Idx)
- if (GEP1->getOperand(Idx) != GEP2->getOperand(Idx))
- break;
-
- bool VariableIdxFound = false;
- int64_t Offset1 = GetOffsetFromIndex(GEP1, Idx, VariableIdxFound, TD);
- int64_t Offset2 = GetOffsetFromIndex(GEP2, Idx, VariableIdxFound, TD);
- if (VariableIdxFound) return false;
-
- Offset = Offset2-Offset1;
- return true;
-}
-
-
-/// MemsetRange - Represents a range of memset'd bytes with the ByteVal value.
-/// This allows us to analyze stores like:
-/// store 0 -> P+1
-/// store 0 -> P+0
-/// store 0 -> P+3
-/// store 0 -> P+2
-/// which sometimes happens with stores to arrays of structs etc. When we see
-/// the first store, we make a range [1, 2). The second store extends the range
-/// to [0, 2). The third makes a new range [2, 3). The fourth store joins the
-/// two ranges into [0, 3) which is memset'able.
-namespace {
-struct MemsetRange {
- // Start/End - A semi range that describes the span that this range covers.
- // The range is closed at the start and open at the end: [Start, End).
- int64_t Start, End;
-
- /// StartPtr - The getelementptr instruction that points to the start of the
- /// range.
- Value *StartPtr;
-
- /// Alignment - The known alignment of the first store.
- unsigned Alignment;
-
- /// TheStores - The actual stores that make up this range.
- SmallVector<StoreInst*, 16> TheStores;
-
- bool isProfitableToUseMemset(const TargetData &TD) const;
-
-};
-} // end anon namespace
-
-bool MemsetRange::isProfitableToUseMemset(const TargetData &TD) const {
- // If we found more than 8 stores to merge or 64 bytes, use memset.
- if (TheStores.size() >= 8 || End-Start >= 64) return true;
-
- // Assume that the code generator is capable of merging pairs of stores
- // together if it wants to.
- if (TheStores.size() <= 2) return false;
-
- // If we have fewer than 8 stores, it can still be worthwhile to do this.
- // For example, merging 4 i8 stores into an i32 store is useful almost always.
- // However, merging 2 32-bit stores isn't useful on a 32-bit architecture (the
- // memset will be split into 2 32-bit stores anyway) and doing so can
- // pessimize the llvm optimizer.
- //
- // Since we don't have perfect knowledge here, make some assumptions: assume
- // the maximum GPR width is the same size as the pointer size and assume that
- // this width can be stored. If so, check to see whether we will end up
- // actually reducing the number of stores used.
- unsigned Bytes = unsigned(End-Start);
- unsigned NumPointerStores = Bytes/TD.getPointerSize();
-
- // Assume the remaining bytes if any are done a byte at a time.
- unsigned NumByteStores = Bytes - NumPointerStores*TD.getPointerSize();
-
- // If we will reduce the # stores (according to this heuristic), do the
- // transformation. This encourages merging 4 x i8 -> i32 and 2 x i16 -> i32
- // etc.
- return TheStores.size() > NumPointerStores+NumByteStores;
-}
-
-
-namespace {
-class MemsetRanges {
- /// Ranges - A sorted list of the memset ranges. We use std::list here
- /// because each element is relatively large and expensive to copy.
- std::list<MemsetRange> Ranges;
- typedef std::list<MemsetRange>::iterator range_iterator;
- TargetData &TD;
-public:
- MemsetRanges(TargetData &td) : TD(td) {}
-
- typedef std::list<MemsetRange>::const_iterator const_iterator;
- const_iterator begin() const { return Ranges.begin(); }
- const_iterator end() const { return Ranges.end(); }
- bool empty() const { return Ranges.empty(); }
-
- void addStore(int64_t OffsetFromFirst, StoreInst *SI);
-};
-
-} // end anon namespace
-
-
-/// addStore - Add a new store to the MemsetRanges data structure. This adds a
-/// new range for the specified store at the specified offset, merging into
-/// existing ranges as appropriate.
-void MemsetRanges::addStore(int64_t Start, StoreInst *SI) {
- int64_t End = Start+TD.getTypeStoreSize(SI->getOperand(0)->getType());
-
- // Do a linear search of the ranges to see if this can be joined and/or to
- // find the insertion point in the list. We keep the ranges sorted for
- // simplicity here. This is a linear search of a linked list, which is ugly,
- // however the number of ranges is limited, so this won't get crazy slow.
- range_iterator I = Ranges.begin(), E = Ranges.end();
-
- while (I != E && Start > I->End)
- ++I;
-
- // We now know that I == E, in which case we didn't find anything to merge
- // with, or that Start <= I->End. If End < I->Start or I == E, then we need
- // to insert a new range. Handle this now.
- if (I == E || End < I->Start) {
- MemsetRange &R = *Ranges.insert(I, MemsetRange());
- R.Start = Start;
- R.End = End;
- R.StartPtr = SI->getPointerOperand();
- R.Alignment = SI->getAlignment();
- R.TheStores.push_back(SI);
- return;
- }
-
- // This store overlaps with I, add it.
- I->TheStores.push_back(SI);
-
- // At this point, we may have an interval that completely contains our store.
- // If so, just add it to the interval and return.
- if (I->Start <= Start && I->End >= End)
- return;
-
- // Now we know that Start <= I->End and End >= I->Start so the range overlaps
- // but is not entirely contained within the range.
-
- // See if the range extends the start of the range. In this case, it couldn't
- // possibly cause it to join the prior range, because otherwise we would have
- // stopped on *it*.
- if (Start < I->Start) {
- I->Start = Start;
- I->StartPtr = SI->getPointerOperand();
- }
-
- // Now we know that Start <= I->End and Start >= I->Start (so the startpoint
- // is in or right at the end of I), and that End >= I->Start. Extend I out to
- // End.
- if (End > I->End) {
- I->End = End;
- range_iterator NextI = I;;
- while (++NextI != E && End >= NextI->Start) {
- // Merge the range in.
- I->TheStores.append(NextI->TheStores.begin(), NextI->TheStores.end());
- if (NextI->End > I->End)
- I->End = NextI->End;
- Ranges.erase(NextI);
- NextI = I;
- }
- }
-}
-
-
-
-/// processStore - When GVN is scanning forward over instructions, we look for
-/// some other patterns to fold away. In particular, this looks for stores to
-/// neighboring locations of memory. If it sees enough consequtive ones
-/// (currently 4) it attempts to merge them together into a memcpy/memset.
-bool GVN::processStore(StoreInst *SI, SmallVectorImpl<Instruction*> &toErase) {
- if (!FormMemSet) return false;
- if (SI->isVolatile()) return false;
-
- // There are two cases that are interesting for this code to handle: memcpy
- // and memset. Right now we only handle memset.
-
- // Ensure that the value being stored is something that can be memset'able a
- // byte at a time like "0" or "-1" or any width, as well as things like
- // 0xA0A0A0A0 and 0.0.
- Value *ByteVal = isBytewiseValue(SI->getOperand(0));
- if (!ByteVal)
- return false;
-
- TargetData &TD = getAnalysis<TargetData>();
- AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
-
- // Okay, so we now have a single store that can be splatable. Scan to find
- // all subsequent stores of the same value to offset from the same pointer.
- // Join these together into ranges, so we can decide whether contiguous blocks
- // are stored.
- MemsetRanges Ranges(TD);
-
- Value *StartPtr = SI->getPointerOperand();
-
- BasicBlock::iterator BI = SI;
- for (++BI; !isa<TerminatorInst>(BI); ++BI) {
- if (isa<CallInst>(BI) || isa<InvokeInst>(BI)) {
- // If the call is readnone, ignore it, otherwise bail out. We don't even
- // allow readonly here because we don't want something like:
- // A[1] = 2; strlen(A); A[2] = 2; -> memcpy(A, ...); strlen(A).
- if (AA.getModRefBehavior(CallSite::get(BI)) ==
- AliasAnalysis::DoesNotAccessMemory)
- continue;
-
- // TODO: If this is a memset, try to join it in.
-
- break;
- } else if (isa<VAArgInst>(BI) || isa<LoadInst>(BI))
- break;
-
- // If this is a non-store instruction it is fine, ignore it.
- StoreInst *NextStore = dyn_cast<StoreInst>(BI);
- if (NextStore == 0) continue;
-
- // If this is a store, see if we can merge it in.
- if (NextStore->isVolatile()) break;
-
- // Check to see if this stored value is of the same byte-splattable value.
- if (ByteVal != isBytewiseValue(NextStore->getOperand(0)))
- break;
-
- // Check to see if this store is to a constant offset from the start ptr.
- int64_t Offset;
- if (!IsPointerOffset(StartPtr, NextStore->getPointerOperand(), Offset, TD))
- break;
-
- Ranges.addStore(Offset, NextStore);
- }
-
- // If we have no ranges, then we just had a single store with nothing that
- // could be merged in. This is a very common case of course.
- if (Ranges.empty())
- return false;
-
- // If we had at least one store that could be merged in, add the starting
- // store as well. We try to avoid this unless there is at least something
- // interesting as a small compile-time optimization.
- Ranges.addStore(0, SI);
-
-
- Function *MemSetF = 0;
-
- // Now that we have full information about ranges, loop over the ranges and
- // emit memset's for anything big enough to be worthwhile.
- bool MadeChange = false;
- for (MemsetRanges::const_iterator I = Ranges.begin(), E = Ranges.end();
- I != E; ++I) {
- const MemsetRange &Range = *I;
-
- if (Range.TheStores.size() == 1) continue;
-
- // If it is profitable to lower this range to memset, do so now.
- if (!Range.isProfitableToUseMemset(TD))
- continue;
-
- // Otherwise, we do want to transform this! Create a new memset. We put
- // the memset right before the first instruction that isn't part of this
- // memset block. This ensure that the memset is dominated by any addressing
- // instruction needed by the start of the block.
- BasicBlock::iterator InsertPt = BI;
-
- if (MemSetF == 0)
- MemSetF = Intrinsic::getDeclaration(SI->getParent()->getParent()
- ->getParent(), Intrinsic::memset_i64);
-
- // Get the starting pointer of the block.
- StartPtr = Range.StartPtr;
-
- // Cast the start ptr to be i8* as memset requires.
- const Type *i8Ptr = PointerType::getUnqual(Type::Int8Ty);
- if (StartPtr->getType() != i8Ptr)
- StartPtr = new BitCastInst(StartPtr, i8Ptr, StartPtr->getNameStart(),
- InsertPt);
-
- Value *Ops[] = {
- StartPtr, ByteVal, // Start, value
- ConstantInt::get(Type::Int64Ty, Range.End-Range.Start), // size
- ConstantInt::get(Type::Int32Ty, Range.Alignment) // align
- };
- Value *C = CallInst::Create(MemSetF, Ops, Ops+4, "", InsertPt);
- DEBUG(cerr << "Replace stores:\n";
- for (unsigned i = 0, e = Range.TheStores.size(); i != e; ++i)
- cerr << *Range.TheStores[i];
- cerr << "With: " << *C); C=C;
-
- // Zap all the stores.
- toErase.append(Range.TheStores.begin(), Range.TheStores.end());
- ++NumMemSetInfer;
- MadeChange = true;
- }
-
- return MadeChange;
-}
-
-
-/// performCallSlotOptzn - takes a memcpy and a call that it depends on,
-/// and checks for the possibility of a call slot optimization by having
-/// the call write its result directly into the destination of the memcpy.
-bool GVN::performCallSlotOptzn(MemCpyInst *cpy, CallInst *C,
- SmallVectorImpl<Instruction*> &toErase) {
- // The general transformation to keep in mind is
- //
- // call @func(..., src, ...)
- // memcpy(dest, src, ...)
- //
- // ->
- //
- // memcpy(dest, src, ...)
- // call @func(..., dest, ...)
- //
- // Since moving the memcpy is technically awkward, we additionally check that
- // src only holds uninitialized values at the moment of the call, meaning that
- // the memcpy can be discarded rather than moved.
-
- // Deliberately get the source and destination with bitcasts stripped away,
- // because we'll need to do type comparisons based on the underlying type.
- Value* cpyDest = cpy->getDest();
- Value* cpySrc = cpy->getSource();
- CallSite CS = CallSite::get(C);
-
- // We need to be able to reason about the size of the memcpy, so we require
- // that it be a constant.
- ConstantInt* cpyLength = dyn_cast<ConstantInt>(cpy->getLength());
- if (!cpyLength)
- return false;
-
- // Require that src be an alloca. This simplifies the reasoning considerably.
- AllocaInst* srcAlloca = dyn_cast<AllocaInst>(cpySrc);
- if (!srcAlloca)
- return false;
-
- // Check that all of src is copied to dest.
- TargetData& TD = getAnalysis<TargetData>();
-
- ConstantInt* srcArraySize = dyn_cast<ConstantInt>(srcAlloca->getArraySize());
- if (!srcArraySize)
- return false;
-
- uint64_t srcSize = TD.getABITypeSize(srcAlloca->getAllocatedType()) *
- srcArraySize->getZExtValue();
-
- if (cpyLength->getZExtValue() < srcSize)
- return false;
-
- // Check that accessing the first srcSize bytes of dest will not cause a
- // trap. Otherwise the transform is invalid since it might cause a trap
- // to occur earlier than it otherwise would.
- if (AllocaInst* A = dyn_cast<AllocaInst>(cpyDest)) {
- // The destination is an alloca. Check it is larger than srcSize.
- ConstantInt* destArraySize = dyn_cast<ConstantInt>(A->getArraySize());
- if (!destArraySize)
- return false;
-
- uint64_t destSize = TD.getABITypeSize(A->getAllocatedType()) *
- destArraySize->getZExtValue();
-
- if (destSize < srcSize)
- return false;
- } else if (Argument* A = dyn_cast<Argument>(cpyDest)) {
- // If the destination is an sret parameter then only accesses that are
- // outside of the returned struct type can trap.
- if (!A->hasStructRetAttr())
- return false;
-
- const Type* StructTy = cast<PointerType>(A->getType())->getElementType();
- uint64_t destSize = TD.getABITypeSize(StructTy);
-
- if (destSize < srcSize)
- return false;
- } else {
- return false;
- }
-
- // Check that src is not accessed except via the call and the memcpy. This
- // guarantees that it holds only undefined values when passed in (so the final
- // memcpy can be dropped), that it is not read or written between the call and
- // the memcpy, and that writing beyond the end of it is undefined.
- SmallVector<User*, 8> srcUseList(srcAlloca->use_begin(),
- srcAlloca->use_end());
- while (!srcUseList.empty()) {
- User* UI = srcUseList.back();
- srcUseList.pop_back();
-
- if (isa<GetElementPtrInst>(UI) || isa<BitCastInst>(UI)) {
- for (User::use_iterator I = UI->use_begin(), E = UI->use_end();
- I != E; ++I)
- srcUseList.push_back(*I);
- } else if (UI != C && UI != cpy) {
- return false;
- }
- }
-
- // Since we're changing the parameter to the callsite, we need to make sure
- // that what would be the new parameter dominates the callsite.
- DominatorTree& DT = getAnalysis<DominatorTree>();
- if (Instruction* cpyDestInst = dyn_cast<Instruction>(cpyDest))
- if (!DT.dominates(cpyDestInst, C))
- return false;
-
- // In addition to knowing that the call does not access src in some
- // unexpected manner, for example via a global, which we deduce from
- // the use analysis, we also need to know that it does not sneakily
- // access dest. We rely on AA to figure this out for us.
- AliasAnalysis& AA = getAnalysis<AliasAnalysis>();
- if (AA.getModRefInfo(C, cpy->getRawDest(), srcSize) !=
- AliasAnalysis::NoModRef)
- return false;
-
- // All the checks have passed, so do the transformation.
- for (unsigned i = 0; i < CS.arg_size(); ++i)
- if (CS.getArgument(i) == cpySrc) {
- if (cpySrc->getType() != cpyDest->getType())
- cpyDest = CastInst::createPointerCast(cpyDest, cpySrc->getType(),
- cpyDest->getName(), C);
- CS.setArgument(i, cpyDest);
- }
-
- // Drop any cached information about the call, because we may have changed
- // its dependence information by changing its parameter.
- MemoryDependenceAnalysis& MD = getAnalysis<MemoryDependenceAnalysis>();
- MD.dropInstruction(C);
-
- // Remove the memcpy
- MD.removeInstruction(cpy);
- toErase.push_back(cpy);
-
- return true;
-}
-
-/// processMemCpy - perform simplication of memcpy's. If we have memcpy A which
-/// copies X to Y, and memcpy B which copies Y to Z, then we can rewrite B to be
-/// a memcpy from X to Z (or potentially a memmove, depending on circumstances).
-/// This allows later passes to remove the first memcpy altogether.
-bool GVN::processMemCpy(MemCpyInst* M, MemCpyInst* MDep,
- SmallVectorImpl<Instruction*> &toErase) {
- // We can only transforms memcpy's where the dest of one is the source of the
- // other
- if (M->getSource() != MDep->getDest())
- return false;
-
- // Second, the length of the memcpy's must be the same, or the preceeding one
- // must be larger than the following one.
- ConstantInt* C1 = dyn_cast<ConstantInt>(MDep->getLength());
- ConstantInt* C2 = dyn_cast<ConstantInt>(M->getLength());
- if (!C1 || !C2)
- return false;
-
- uint64_t DepSize = C1->getValue().getZExtValue();
- uint64_t CpySize = C2->getValue().getZExtValue();
-
- if (DepSize < CpySize)
- return false;
-
- // Finally, we have to make sure that the dest of the second does not
- // alias the source of the first
- AliasAnalysis& AA = getAnalysis<AliasAnalysis>();
- if (AA.alias(M->getRawDest(), CpySize, MDep->getRawSource(), DepSize) !=
- AliasAnalysis::NoAlias)
- return false;
- else if (AA.alias(M->getRawDest(), CpySize, M->getRawSource(), CpySize) !=
- AliasAnalysis::NoAlias)
- return false;
- else if (AA.alias(MDep->getRawDest(), DepSize, MDep->getRawSource(), DepSize)
- != AliasAnalysis::NoAlias)
- return false;
-
- // If all checks passed, then we can transform these memcpy's
- Function* MemCpyFun = Intrinsic::getDeclaration(
- M->getParent()->getParent()->getParent(),
- M->getIntrinsicID());
-
- std::vector<Value*> args;
- args.push_back(M->getRawDest());
- args.push_back(MDep->getRawSource());
- args.push_back(M->getLength());
- args.push_back(M->getAlignment());
-
- CallInst* C = CallInst::Create(MemCpyFun, args.begin(), args.end(), "", M);
-
- MemoryDependenceAnalysis& MD = getAnalysis<MemoryDependenceAnalysis>();
- if (MD.getDependency(C) == MDep) {
- MD.dropInstruction(M);
- toErase.push_back(M);
- return true;
- }
-
- MD.removeInstruction(C);
- toErase.push_back(C);
- return false;
-}
-
/// processInstruction - When calculating availability, handle an instruction
/// by inserting it into the appropriate sets
bool GVN::processInstruction(Instruction *I, ValueNumberedSet &currAvail,
@@ -1578,31 +978,11 @@
if (LoadInst* L = dyn_cast<LoadInst>(I))
return processLoad(L, lastSeenLoad, toErase);
- if (StoreInst *SI = dyn_cast<StoreInst>(I))
- return processStore(SI, toErase);
-
// Allocations are always uniquely numbered, so we can save time and memory
// by fast failing them.
if (isa<AllocationInst>(I))
return false;
- if (MemCpyInst* M = dyn_cast<MemCpyInst>(I)) {
- MemoryDependenceAnalysis& MD = getAnalysis<MemoryDependenceAnalysis>();
-
- // The are two possible optimizations we can do for memcpy:
- // a) memcpy-memcpy xform which exposes redundance for DSE
- // b) call-memcpy xform for return slot optimization
- Instruction* dep = MD.getDependency(M);
- if (dep == MemoryDependenceAnalysis::None ||
- dep == MemoryDependenceAnalysis::NonLocal)
- return false;
- if (MemCpyInst *MemCpy = dyn_cast<MemCpyInst>(dep))
- return processMemCpy(M, MemCpy, toErase);
- if (CallInst* C = dyn_cast<CallInst>(dep))
- return performCallSlotOptzn(M, C, toErase);
- return false;
- }
-
unsigned num = VN.lookup_or_add(I);
// Collapse PHI nodes
Added: llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp?rev=49419&view=auto
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp (added)
+++ llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp Wed Apr 9 03:23:16 2008
@@ -0,0 +1,769 @@
+//===- MemCpyOptimizer.cpp - Optimize use of memcpy and friends -----------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass performs various transformations related to eliminating memcpy
+// calls, or transforming sets of stores into memset's.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "memcpyopt"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/BasicBlock.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/IntrinsicInst.h"
+#include "llvm/Instructions.h"
+#include "llvm/ParameterAttributes.h"
+#include "llvm/Value.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/Dominators.h"
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/MemoryDependenceAnalysis.h"
+#include "llvm/Support/CFG.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/GetElementPtrTypeIterator.h"
+#include "llvm/Target/TargetData.h"
+#include <list>
+using namespace llvm;
+
+STATISTIC(NumMemCpyInstr, "Number of memcpy instructions deleted");
+STATISTIC(NumMemSetInfer, "Number of memsets inferred");
+
+namespace {
+ cl::opt<bool>
+ FormMemSet("form-memset-from-stores",
+ cl::desc("Transform straight-line stores to memsets"),
+ cl::init(true), cl::Hidden);
+}
+
+/// isBytewiseValue - If the specified value can be set by repeating the same
+/// byte in memory, return the i8 value that it is represented with. This is
+/// true for all i8 values obviously, but is also true for i32 0, i32 -1,
+/// i16 0xF0F0, double 0.0 etc. If the value can't be handled with a repeated
+/// byte store (e.g. i16 0x1234), return null.
+static Value *isBytewiseValue(Value *V) {
+ // All byte-wide stores are splatable, even of arbitrary variables.
+ if (V->getType() == Type::Int8Ty) return V;
+
+ // Constant float and double values can be handled as integer values if the
+ // corresponding integer value is "byteable". An important case is 0.0.
+ if (ConstantFP *CFP = dyn_cast<ConstantFP>(V)) {
+ if (CFP->getType() == Type::FloatTy)
+ V = ConstantExpr::getBitCast(CFP, Type::Int32Ty);
+ if (CFP->getType() == Type::DoubleTy)
+ V = ConstantExpr::getBitCast(CFP, Type::Int64Ty);
+ // Don't handle long double formats, which have strange constraints.
+ }
+
+ // We can handle constant integers that are power of two in size and a
+ // multiple of 8 bits.
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ unsigned Width = CI->getBitWidth();
+ if (isPowerOf2_32(Width) && Width > 8) {
+ // We can handle this value if the recursive binary decomposition is the
+ // same at all levels.
+ APInt Val = CI->getValue();
+ APInt Val2;
+ while (Val.getBitWidth() != 8) {
+ unsigned NextWidth = Val.getBitWidth()/2;
+ Val2 = Val.lshr(NextWidth);
+ Val2.trunc(Val.getBitWidth()/2);
+ Val.trunc(Val.getBitWidth()/2);
+
+ // If the top/bottom halves aren't the same, reject it.
+ if (Val != Val2)
+ return 0;
+ }
+ return ConstantInt::get(Val);
+ }
+ }
+
+ // Conceptually, we could handle things like:
+ // %a = zext i8 %X to i16
+ // %b = shl i16 %a, 8
+ // %c = or i16 %a, %b
+ // but until there is an example that actually needs this, it doesn't seem
+ // worth worrying about.
+ return 0;
+}
+
+static int64_t GetOffsetFromIndex(const GetElementPtrInst *GEP, unsigned Idx,
+ bool &VariableIdxFound, TargetData &TD) {
+ // Skip over the first indices.
+ gep_type_iterator GTI = gep_type_begin(GEP);
+ for (unsigned i = 1; i != Idx; ++i, ++GTI)
+ /*skip along*/;
+
+ // Compute the offset implied by the rest of the indices.
+ int64_t Offset = 0;
+ for (unsigned i = Idx, e = GEP->getNumOperands(); i != e; ++i, ++GTI) {
+ ConstantInt *OpC = dyn_cast<ConstantInt>(GEP->getOperand(i));
+ if (OpC == 0)
+ return VariableIdxFound = true;
+ if (OpC->isZero()) continue; // No offset.
+
+ // Handle struct indices, which add their field offset to the pointer.
+ if (const StructType *STy = dyn_cast<StructType>(*GTI)) {
+ Offset += TD.getStructLayout(STy)->getElementOffset(OpC->getZExtValue());
+ continue;
+ }
+
+ // Otherwise, we have a sequential type like an array or vector. Multiply
+ // the index by the ElementSize.
+ uint64_t Size = TD.getABITypeSize(GTI.getIndexedType());
+ Offset += Size*OpC->getSExtValue();
+ }
+
+ return Offset;
+}
+
+/// IsPointerOffset - Return true if Ptr1 is provably equal to Ptr2 plus a
+/// constant offset, and return that constant offset. For example, Ptr1 might
+/// be &A[42], and Ptr2 might be &A[40]. In this case offset would be -8.
+static bool IsPointerOffset(Value *Ptr1, Value *Ptr2, int64_t &Offset,
+ TargetData &TD) {
+ // Right now we handle the case when Ptr1/Ptr2 are both GEPs with an identical
+ // base. After that base, they may have some number of common (and
+ // potentially variable) indices. After that they handle some constant
+ // offset, which determines their offset from each other. At this point, we
+ // handle no other case.
+ GetElementPtrInst *GEP1 = dyn_cast<GetElementPtrInst>(Ptr1);
+ GetElementPtrInst *GEP2 = dyn_cast<GetElementPtrInst>(Ptr2);
+ if (!GEP1 || !GEP2 || GEP1->getOperand(0) != GEP2->getOperand(0))
+ return false;
+
+ // Skip any common indices and track the GEP types.
+ unsigned Idx = 1;
+ for (; Idx != GEP1->getNumOperands() && Idx != GEP2->getNumOperands(); ++Idx)
+ if (GEP1->getOperand(Idx) != GEP2->getOperand(Idx))
+ break;
+
+ bool VariableIdxFound = false;
+ int64_t Offset1 = GetOffsetFromIndex(GEP1, Idx, VariableIdxFound, TD);
+ int64_t Offset2 = GetOffsetFromIndex(GEP2, Idx, VariableIdxFound, TD);
+ if (VariableIdxFound) return false;
+
+ Offset = Offset2-Offset1;
+ return true;
+}
+
+
+/// MemsetRange - Represents a range of memset'd bytes with the ByteVal value.
+/// This allows us to analyze stores like:
+/// store 0 -> P+1
+/// store 0 -> P+0
+/// store 0 -> P+3
+/// store 0 -> P+2
+/// which sometimes happens with stores to arrays of structs etc. When we see
+/// the first store, we make a range [1, 2). The second store extends the range
+/// to [0, 2). The third makes a new range [2, 3). The fourth store joins the
+/// two ranges into [0, 3) which is memset'able.
+namespace {
+struct MemsetRange {
+ // Start/End - A semi range that describes the span that this range covers.
+ // The range is closed at the start and open at the end: [Start, End).
+ int64_t Start, End;
+
+ /// StartPtr - The getelementptr instruction that points to the start of the
+ /// range.
+ Value *StartPtr;
+
+ /// Alignment - The known alignment of the first store.
+ unsigned Alignment;
+
+ /// TheStores - The actual stores that make up this range.
+ SmallVector<StoreInst*, 16> TheStores;
+
+ bool isProfitableToUseMemset(const TargetData &TD) const;
+
+};
+} // end anon namespace
+
+bool MemsetRange::isProfitableToUseMemset(const TargetData &TD) const {
+ // If we found more than 8 stores to merge or 64 bytes, use memset.
+ if (TheStores.size() >= 8 || End-Start >= 64) return true;
+
+ // Assume that the code generator is capable of merging pairs of stores
+ // together if it wants to.
+ if (TheStores.size() <= 2) return false;
+
+ // If we have fewer than 8 stores, it can still be worthwhile to do this.
+ // For example, merging 4 i8 stores into an i32 store is useful almost always.
+ // However, merging 2 32-bit stores isn't useful on a 32-bit architecture (the
+ // memset will be split into 2 32-bit stores anyway) and doing so can
+ // pessimize the llvm optimizer.
+ //
+ // Since we don't have perfect knowledge here, make some assumptions: assume
+ // the maximum GPR width is the same size as the pointer size and assume that
+ // this width can be stored. If so, check to see whether we will end up
+ // actually reducing the number of stores used.
+ unsigned Bytes = unsigned(End-Start);
+ unsigned NumPointerStores = Bytes/TD.getPointerSize();
+
+ // Assume the remaining bytes if any are done a byte at a time.
+ unsigned NumByteStores = Bytes - NumPointerStores*TD.getPointerSize();
+
+ // If we will reduce the # stores (according to this heuristic), do the
+ // transformation. This encourages merging 4 x i8 -> i32 and 2 x i16 -> i32
+ // etc.
+ return TheStores.size() > NumPointerStores+NumByteStores;
+}
+
+
+namespace {
+class MemsetRanges {
+ /// Ranges - A sorted list of the memset ranges. We use std::list here
+ /// because each element is relatively large and expensive to copy.
+ std::list<MemsetRange> Ranges;
+ typedef std::list<MemsetRange>::iterator range_iterator;
+ TargetData &TD;
+public:
+ MemsetRanges(TargetData &td) : TD(td) {}
+
+ typedef std::list<MemsetRange>::const_iterator const_iterator;
+ const_iterator begin() const { return Ranges.begin(); }
+ const_iterator end() const { return Ranges.end(); }
+ bool empty() const { return Ranges.empty(); }
+
+ void addStore(int64_t OffsetFromFirst, StoreInst *SI);
+};
+
+} // end anon namespace
+
+
+/// addStore - Add a new store to the MemsetRanges data structure. This adds a
+/// new range for the specified store at the specified offset, merging into
+/// existing ranges as appropriate.
+void MemsetRanges::addStore(int64_t Start, StoreInst *SI) {
+ int64_t End = Start+TD.getTypeStoreSize(SI->getOperand(0)->getType());
+
+ // Do a linear search of the ranges to see if this can be joined and/or to
+ // find the insertion point in the list. We keep the ranges sorted for
+ // simplicity here. This is a linear search of a linked list, which is ugly,
+ // however the number of ranges is limited, so this won't get crazy slow.
+ range_iterator I = Ranges.begin(), E = Ranges.end();
+
+ while (I != E && Start > I->End)
+ ++I;
+
+ // We now know that I == E, in which case we didn't find anything to merge
+ // with, or that Start <= I->End. If End < I->Start or I == E, then we need
+ // to insert a new range. Handle this now.
+ if (I == E || End < I->Start) {
+ MemsetRange &R = *Ranges.insert(I, MemsetRange());
+ R.Start = Start;
+ R.End = End;
+ R.StartPtr = SI->getPointerOperand();
+ R.Alignment = SI->getAlignment();
+ R.TheStores.push_back(SI);
+ return;
+ }
+
+ // This store overlaps with I, add it.
+ I->TheStores.push_back(SI);
+
+ // At this point, we may have an interval that completely contains our store.
+ // If so, just add it to the interval and return.
+ if (I->Start <= Start && I->End >= End)
+ return;
+
+ // Now we know that Start <= I->End and End >= I->Start so the range overlaps
+ // but is not entirely contained within the range.
+
+ // See if the range extends the start of the range. In this case, it couldn't
+ // possibly cause it to join the prior range, because otherwise we would have
+ // stopped on *it*.
+ if (Start < I->Start) {
+ I->Start = Start;
+ I->StartPtr = SI->getPointerOperand();
+ }
+
+ // Now we know that Start <= I->End and Start >= I->Start (so the startpoint
+ // is in or right at the end of I), and that End >= I->Start. Extend I out to
+ // End.
+ if (End > I->End) {
+ I->End = End;
+ range_iterator NextI = I;;
+ while (++NextI != E && End >= NextI->Start) {
+ // Merge the range in.
+ I->TheStores.append(NextI->TheStores.begin(), NextI->TheStores.end());
+ if (NextI->End > I->End)
+ I->End = NextI->End;
+ Ranges.erase(NextI);
+ NextI = I;
+ }
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// MemCpyOpt Pass
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+ class VISIBILITY_HIDDEN MemCpyOpt : public FunctionPass {
+ bool runOnFunction(Function &F);
+ public:
+ static char ID; // Pass identification, replacement for typeid
+ MemCpyOpt() : FunctionPass((intptr_t)&ID) { }
+
+ private:
+ // This transformation requires dominator postdominator info
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesCFG();
+ AU.addRequired<DominatorTree>();
+ AU.addRequired<MemoryDependenceAnalysis>();
+ AU.addRequired<AliasAnalysis>();
+ AU.addRequired<TargetData>();
+ AU.addPreserved<AliasAnalysis>();
+ AU.addPreserved<MemoryDependenceAnalysis>();
+ AU.addPreserved<TargetData>();
+ }
+
+ // Helper fuctions
+ bool processInstruction(Instruction* I,
+ SmallVectorImpl<Instruction*> &toErase);
+ bool processStore(StoreInst *SI, SmallVectorImpl<Instruction*> &toErase);
+ bool processMemCpy(MemCpyInst* M, MemCpyInst* MDep,
+ SmallVectorImpl<Instruction*> &toErase);
+ bool performCallSlotOptzn(MemCpyInst* cpy, CallInst* C,
+ SmallVectorImpl<Instruction*> &toErase);
+ bool iterateOnFunction(Function &F);
+ };
+
+ char MemCpyOpt::ID = 0;
+}
+
+// createMemCpyOptPass - The public interface to this file...
+FunctionPass *llvm::createMemCpyOptPass() { return new MemCpyOpt(); }
+
+static RegisterPass<MemCpyOpt> X("memcpyopt",
+ "MemCpy Optimization");
+
+
+
+/// processStore - When GVN is scanning forward over instructions, we look for
+/// some other patterns to fold away. In particular, this looks for stores to
+/// neighboring locations of memory. If it sees enough consequtive ones
+/// (currently 4) it attempts to merge them together into a memcpy/memset.
+bool MemCpyOpt::processStore(StoreInst *SI, SmallVectorImpl<Instruction*> &toErase) {
+ if (!FormMemSet) return false;
+ if (SI->isVolatile()) return false;
+
+ // There are two cases that are interesting for this code to handle: memcpy
+ // and memset. Right now we only handle memset.
+
+ // Ensure that the value being stored is something that can be memset'able a
+ // byte at a time like "0" or "-1" or any width, as well as things like
+ // 0xA0A0A0A0 and 0.0.
+ Value *ByteVal = isBytewiseValue(SI->getOperand(0));
+ if (!ByteVal)
+ return false;
+
+ TargetData &TD = getAnalysis<TargetData>();
+ AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
+
+ // Okay, so we now have a single store that can be splatable. Scan to find
+ // all subsequent stores of the same value to offset from the same pointer.
+ // Join these together into ranges, so we can decide whether contiguous blocks
+ // are stored.
+ MemsetRanges Ranges(TD);
+
+ Value *StartPtr = SI->getPointerOperand();
+
+ BasicBlock::iterator BI = SI;
+ for (++BI; !isa<TerminatorInst>(BI); ++BI) {
+ if (isa<CallInst>(BI) || isa<InvokeInst>(BI)) {
+ // If the call is readnone, ignore it, otherwise bail out. We don't even
+ // allow readonly here because we don't want something like:
+ // A[1] = 2; strlen(A); A[2] = 2; -> memcpy(A, ...); strlen(A).
+ if (AA.getModRefBehavior(CallSite::get(BI)) ==
+ AliasAnalysis::DoesNotAccessMemory)
+ continue;
+
+ // TODO: If this is a memset, try to join it in.
+
+ break;
+ } else if (isa<VAArgInst>(BI) || isa<LoadInst>(BI))
+ break;
+
+ // If this is a non-store instruction it is fine, ignore it.
+ StoreInst *NextStore = dyn_cast<StoreInst>(BI);
+ if (NextStore == 0) continue;
+
+ // If this is a store, see if we can merge it in.
+ if (NextStore->isVolatile()) break;
+
+ // Check to see if this stored value is of the same byte-splattable value.
+ if (ByteVal != isBytewiseValue(NextStore->getOperand(0)))
+ break;
+
+ // Check to see if this store is to a constant offset from the start ptr.
+ int64_t Offset;
+ if (!IsPointerOffset(StartPtr, NextStore->getPointerOperand(), Offset, TD))
+ break;
+
+ Ranges.addStore(Offset, NextStore);
+ }
+
+ // If we have no ranges, then we just had a single store with nothing that
+ // could be merged in. This is a very common case of course.
+ if (Ranges.empty())
+ return false;
+
+ // If we had at least one store that could be merged in, add the starting
+ // store as well. We try to avoid this unless there is at least something
+ // interesting as a small compile-time optimization.
+ Ranges.addStore(0, SI);
+
+
+ Function *MemSetF = 0;
+
+ // Now that we have full information about ranges, loop over the ranges and
+ // emit memset's for anything big enough to be worthwhile.
+ bool MadeChange = false;
+ for (MemsetRanges::const_iterator I = Ranges.begin(), E = Ranges.end();
+ I != E; ++I) {
+ const MemsetRange &Range = *I;
+
+ if (Range.TheStores.size() == 1) continue;
+
+ // If it is profitable to lower this range to memset, do so now.
+ if (!Range.isProfitableToUseMemset(TD))
+ continue;
+
+ // Otherwise, we do want to transform this! Create a new memset. We put
+ // the memset right before the first instruction that isn't part of this
+ // memset block. This ensure that the memset is dominated by any addressing
+ // instruction needed by the start of the block.
+ BasicBlock::iterator InsertPt = BI;
+
+ if (MemSetF == 0)
+ MemSetF = Intrinsic::getDeclaration(SI->getParent()->getParent()
+ ->getParent(), Intrinsic::memset_i64);
+
+ // Get the starting pointer of the block.
+ StartPtr = Range.StartPtr;
+
+ // Cast the start ptr to be i8* as memset requires.
+ const Type *i8Ptr = PointerType::getUnqual(Type::Int8Ty);
+ if (StartPtr->getType() != i8Ptr)
+ StartPtr = new BitCastInst(StartPtr, i8Ptr, StartPtr->getNameStart(),
+ InsertPt);
+
+ Value *Ops[] = {
+ StartPtr, ByteVal, // Start, value
+ ConstantInt::get(Type::Int64Ty, Range.End-Range.Start), // size
+ ConstantInt::get(Type::Int32Ty, Range.Alignment) // align
+ };
+ Value *C = CallInst::Create(MemSetF, Ops, Ops+4, "", InsertPt);
+ DEBUG(cerr << "Replace stores:\n";
+ for (unsigned i = 0, e = Range.TheStores.size(); i != e; ++i)
+ cerr << *Range.TheStores[i];
+ cerr << "With: " << *C); C=C;
+
+ // Zap all the stores.
+ toErase.append(Range.TheStores.begin(), Range.TheStores.end());
+ ++NumMemSetInfer;
+ MadeChange = true;
+ }
+
+ return MadeChange;
+}
+
+
+/// performCallSlotOptzn - takes a memcpy and a call that it depends on,
+/// and checks for the possibility of a call slot optimization by having
+/// the call write its result directly into the destination of the memcpy.
+bool MemCpyOpt::performCallSlotOptzn(MemCpyInst *cpy, CallInst *C,
+ SmallVectorImpl<Instruction*> &toErase) {
+ // The general transformation to keep in mind is
+ //
+ // call @func(..., src, ...)
+ // memcpy(dest, src, ...)
+ //
+ // ->
+ //
+ // memcpy(dest, src, ...)
+ // call @func(..., dest, ...)
+ //
+ // Since moving the memcpy is technically awkward, we additionally check that
+ // src only holds uninitialized values at the moment of the call, meaning that
+ // the memcpy can be discarded rather than moved.
+
+ // Deliberately get the source and destination with bitcasts stripped away,
+ // because we'll need to do type comparisons based on the underlying type.
+ Value* cpyDest = cpy->getDest();
+ Value* cpySrc = cpy->getSource();
+ CallSite CS = CallSite::get(C);
+
+ // We need to be able to reason about the size of the memcpy, so we require
+ // that it be a constant.
+ ConstantInt* cpyLength = dyn_cast<ConstantInt>(cpy->getLength());
+ if (!cpyLength)
+ return false;
+
+ // Require that src be an alloca. This simplifies the reasoning considerably.
+ AllocaInst* srcAlloca = dyn_cast<AllocaInst>(cpySrc);
+ if (!srcAlloca)
+ return false;
+
+ // Check that all of src is copied to dest.
+ TargetData& TD = getAnalysis<TargetData>();
+
+ ConstantInt* srcArraySize = dyn_cast<ConstantInt>(srcAlloca->getArraySize());
+ if (!srcArraySize)
+ return false;
+
+ uint64_t srcSize = TD.getABITypeSize(srcAlloca->getAllocatedType()) *
+ srcArraySize->getZExtValue();
+
+ if (cpyLength->getZExtValue() < srcSize)
+ return false;
+
+ // Check that accessing the first srcSize bytes of dest will not cause a
+ // trap. Otherwise the transform is invalid since it might cause a trap
+ // to occur earlier than it otherwise would.
+ if (AllocaInst* A = dyn_cast<AllocaInst>(cpyDest)) {
+ // The destination is an alloca. Check it is larger than srcSize.
+ ConstantInt* destArraySize = dyn_cast<ConstantInt>(A->getArraySize());
+ if (!destArraySize)
+ return false;
+
+ uint64_t destSize = TD.getABITypeSize(A->getAllocatedType()) *
+ destArraySize->getZExtValue();
+
+ if (destSize < srcSize)
+ return false;
+ } else if (Argument* A = dyn_cast<Argument>(cpyDest)) {
+ // If the destination is an sret parameter then only accesses that are
+ // outside of the returned struct type can trap.
+ if (!A->hasStructRetAttr())
+ return false;
+
+ const Type* StructTy = cast<PointerType>(A->getType())->getElementType();
+ uint64_t destSize = TD.getABITypeSize(StructTy);
+
+ if (destSize < srcSize)
+ return false;
+ } else {
+ return false;
+ }
+
+ // Check that src is not accessed except via the call and the memcpy. This
+ // guarantees that it holds only undefined values when passed in (so the final
+ // memcpy can be dropped), that it is not read or written between the call and
+ // the memcpy, and that writing beyond the end of it is undefined.
+ SmallVector<User*, 8> srcUseList(srcAlloca->use_begin(),
+ srcAlloca->use_end());
+ while (!srcUseList.empty()) {
+ User* UI = srcUseList.back();
+ srcUseList.pop_back();
+
+ if (isa<GetElementPtrInst>(UI) || isa<BitCastInst>(UI)) {
+ for (User::use_iterator I = UI->use_begin(), E = UI->use_end();
+ I != E; ++I)
+ srcUseList.push_back(*I);
+ } else if (UI != C && UI != cpy) {
+ return false;
+ }
+ }
+
+ // Since we're changing the parameter to the callsite, we need to make sure
+ // that what would be the new parameter dominates the callsite.
+ DominatorTree& DT = getAnalysis<DominatorTree>();
+ if (Instruction* cpyDestInst = dyn_cast<Instruction>(cpyDest))
+ if (!DT.dominates(cpyDestInst, C))
+ return false;
+
+ // In addition to knowing that the call does not access src in some
+ // unexpected manner, for example via a global, which we deduce from
+ // the use analysis, we also need to know that it does not sneakily
+ // access dest. We rely on AA to figure this out for us.
+ AliasAnalysis& AA = getAnalysis<AliasAnalysis>();
+ if (AA.getModRefInfo(C, cpy->getRawDest(), srcSize) !=
+ AliasAnalysis::NoModRef)
+ return false;
+
+ // All the checks have passed, so do the transformation.
+ for (unsigned i = 0; i < CS.arg_size(); ++i)
+ if (CS.getArgument(i) == cpySrc) {
+ if (cpySrc->getType() != cpyDest->getType())
+ cpyDest = CastInst::createPointerCast(cpyDest, cpySrc->getType(),
+ cpyDest->getName(), C);
+ CS.setArgument(i, cpyDest);
+ }
+
+ // Drop any cached information about the call, because we may have changed
+ // its dependence information by changing its parameter.
+ MemoryDependenceAnalysis& MD = getAnalysis<MemoryDependenceAnalysis>();
+ MD.dropInstruction(C);
+
+ // Remove the memcpy
+ MD.removeInstruction(cpy);
+ toErase.push_back(cpy);
+
+ return true;
+}
+
+/// processMemCpy - perform simplication of memcpy's. If we have memcpy A which
+/// copies X to Y, and memcpy B which copies Y to Z, then we can rewrite B to be
+/// a memcpy from X to Z (or potentially a memmove, depending on circumstances).
+/// This allows later passes to remove the first memcpy altogether.
+bool MemCpyOpt::processMemCpy(MemCpyInst* M, MemCpyInst* MDep,
+ SmallVectorImpl<Instruction*> &toErase) {
+ // We can only transforms memcpy's where the dest of one is the source of the
+ // other
+ if (M->getSource() != MDep->getDest())
+ return false;
+
+ // Second, the length of the memcpy's must be the same, or the preceeding one
+ // must be larger than the following one.
+ ConstantInt* C1 = dyn_cast<ConstantInt>(MDep->getLength());
+ ConstantInt* C2 = dyn_cast<ConstantInt>(M->getLength());
+ if (!C1 || !C2)
+ return false;
+
+ uint64_t DepSize = C1->getValue().getZExtValue();
+ uint64_t CpySize = C2->getValue().getZExtValue();
+
+ if (DepSize < CpySize)
+ return false;
+
+ // Finally, we have to make sure that the dest of the second does not
+ // alias the source of the first
+ AliasAnalysis& AA = getAnalysis<AliasAnalysis>();
+ if (AA.alias(M->getRawDest(), CpySize, MDep->getRawSource(), DepSize) !=
+ AliasAnalysis::NoAlias)
+ return false;
+ else if (AA.alias(M->getRawDest(), CpySize, M->getRawSource(), CpySize) !=
+ AliasAnalysis::NoAlias)
+ return false;
+ else if (AA.alias(MDep->getRawDest(), DepSize, MDep->getRawSource(), DepSize)
+ != AliasAnalysis::NoAlias)
+ return false;
+
+ // If all checks passed, then we can transform these memcpy's
+ Function* MemCpyFun = Intrinsic::getDeclaration(
+ M->getParent()->getParent()->getParent(),
+ M->getIntrinsicID());
+
+ std::vector<Value*> args;
+ args.push_back(M->getRawDest());
+ args.push_back(MDep->getRawSource());
+ args.push_back(M->getLength());
+ args.push_back(M->getAlignment());
+
+ CallInst* C = CallInst::Create(MemCpyFun, args.begin(), args.end(), "", M);
+
+ MemoryDependenceAnalysis& MD = getAnalysis<MemoryDependenceAnalysis>();
+ if (MD.getDependency(C) == MDep) {
+ MD.dropInstruction(M);
+ toErase.push_back(M);
+ return true;
+ }
+
+ MD.removeInstruction(C);
+ toErase.push_back(C);
+ return false;
+}
+
+/// processInstruction - When calculating availability, handle an instruction
+/// by inserting it into the appropriate sets
+bool MemCpyOpt::processInstruction(Instruction *I,
+ SmallVectorImpl<Instruction*> &toErase) {
+ if (StoreInst *SI = dyn_cast<StoreInst>(I))
+ return processStore(SI, toErase);
+
+ if (MemCpyInst* M = dyn_cast<MemCpyInst>(I)) {
+ MemoryDependenceAnalysis& MD = getAnalysis<MemoryDependenceAnalysis>();
+
+ // The are two possible optimizations we can do for memcpy:
+ // a) memcpy-memcpy xform which exposes redundance for DSE
+ // b) call-memcpy xform for return slot optimization
+ Instruction* dep = MD.getDependency(M);
+ if (dep == MemoryDependenceAnalysis::None ||
+ dep == MemoryDependenceAnalysis::NonLocal)
+ return false;
+ if (MemCpyInst *MemCpy = dyn_cast<MemCpyInst>(dep))
+ return processMemCpy(M, MemCpy, toErase);
+ if (CallInst* C = dyn_cast<CallInst>(dep))
+ return performCallSlotOptzn(M, C, toErase);
+ return false;
+ }
+
+ return false;
+}
+
+// MemCpyOpt::runOnFunction - This is the main transformation entry point for a
+// function.
+//
+bool MemCpyOpt::runOnFunction(Function& F) {
+
+ bool changed = false;
+ bool shouldContinue = true;
+
+ while (shouldContinue) {
+ shouldContinue = iterateOnFunction(F);
+ changed |= shouldContinue;
+ }
+
+ return changed;
+}
+
+
+// MemCpyOpt::iterateOnFunction - Executes one iteration of GVN
+bool MemCpyOpt::iterateOnFunction(Function &F) {
+ bool changed_function = false;
+
+ DominatorTree &DT = getAnalysis<DominatorTree>();
+
+ SmallVector<Instruction*, 8> toErase;
+
+ // Top-down walk of the dominator tree
+ for (df_iterator<DomTreeNode*> DI = df_begin(DT.getRootNode()),
+ E = df_end(DT.getRootNode()); DI != E; ++DI) {
+
+ BasicBlock* BB = DI->getBlock();
+ for (BasicBlock::iterator BI = BB->begin(), BE = BB->end();
+ BI != BE;) {
+ changed_function |= processInstruction(BI, toErase);
+ if (toErase.empty()) {
+ ++BI;
+ continue;
+ }
+
+ // If we need some instructions deleted, do it now.
+ NumMemCpyInstr += toErase.size();
+
+ // Avoid iterator invalidation.
+ bool AtStart = BI == BB->begin();
+ if (!AtStart)
+ --BI;
+
+ for (SmallVector<Instruction*, 4>::iterator I = toErase.begin(),
+ E = toErase.end(); I != E; ++I)
+ (*I)->eraseFromParent();
+
+ if (AtStart)
+ BI = BB->begin();
+ else
+ ++BI;
+
+ toErase.clear();
+ }
+ }
+
+ return changed_function;
+}
Removed: llvm/trunk/test/Transforms/GVN/2008-02-24-MultipleUseofSRet.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/2008-02-24-MultipleUseofSRet.ll?rev=49418&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/GVN/2008-02-24-MultipleUseofSRet.ll (original)
+++ llvm/trunk/test/Transforms/GVN/2008-02-24-MultipleUseofSRet.ll (removed)
@@ -1,34 +0,0 @@
-; RUN: llvm-as < %s | opt -gvn -dse | llvm-dis | grep {call.*initialize} | not grep memtmp
-; PR2077
-
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
-target triple = "i386-pc-linux-gnu"
-
-define internal fastcc void @initialize({ x86_fp80, x86_fp80 }* noalias sret %agg.result) nounwind {
-entry:
- %agg.result.03 = getelementptr { x86_fp80, x86_fp80 }* %agg.result, i32 0, i32 0 ; <x86_fp80*> [#uses=1]
- store x86_fp80 0xK00000000000000000000, x86_fp80* %agg.result.03
- %agg.result.15 = getelementptr { x86_fp80, x86_fp80 }* %agg.result, i32 0, i32 1 ; <x86_fp80*> [#uses=1]
- store x86_fp80 0xK00000000000000000000, x86_fp80* %agg.result.15
- ret void
-}
-
-declare fastcc x86_fp80 @passed_uninitialized({ x86_fp80, x86_fp80 }* %x) nounwind
-
-define fastcc void @badly_optimized() nounwind {
-entry:
- %z = alloca { x86_fp80, x86_fp80 } ; <{ x86_fp80, x86_fp80 }*> [#uses=2]
- %tmp = alloca { x86_fp80, x86_fp80 } ; <{ x86_fp80, x86_fp80 }*> [#uses=2]
- %memtmp = alloca { x86_fp80, x86_fp80 }, align 8 ; <{ x86_fp80, x86_fp80 }*> [#uses=2]
- call fastcc void @initialize( { x86_fp80, x86_fp80 }* noalias sret %memtmp )
- %tmp1 = bitcast { x86_fp80, x86_fp80 }* %tmp to i8* ; <i8*> [#uses=1]
- %memtmp2 = bitcast { x86_fp80, x86_fp80 }* %memtmp to i8* ; <i8*> [#uses=1]
- call void @llvm.memcpy.i32( i8* %tmp1, i8* %memtmp2, i32 24, i32 8 )
- %z3 = bitcast { x86_fp80, x86_fp80 }* %z to i8* ; <i8*> [#uses=1]
- %tmp4 = bitcast { x86_fp80, x86_fp80 }* %tmp to i8* ; <i8*> [#uses=1]
- call void @llvm.memcpy.i32( i8* %z3, i8* %tmp4, i32 24, i32 8 )
- %tmp5 = call fastcc x86_fp80 @passed_uninitialized( { x86_fp80, x86_fp80 }* %z ) ; <x86_fp80> [#uses=0]
- ret void
-}
-
-declare void @llvm.memcpy.i32(i8*, i8*, i32, i32) nounwind
Removed: llvm/trunk/test/Transforms/GVN/2008-03-13-ReturnSlotBitcast.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/2008-03-13-ReturnSlotBitcast.ll?rev=49418&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/GVN/2008-03-13-ReturnSlotBitcast.ll (original)
+++ llvm/trunk/test/Transforms/GVN/2008-03-13-ReturnSlotBitcast.ll (removed)
@@ -1,19 +0,0 @@
-; RUN: llvm-as < %s | opt -gvn | llvm-dis | not grep {call.*memcpy.}
- %a = type { i32 }
- %b = type { float }
-
-declare void @llvm.memcpy.i32(i8*, i8*, i32, i32) nounwind
-declare void @g(%a*)
-
-define float @f() {
-entry:
- %a_var = alloca %a
- %b_var = alloca %b
- call void @g(%a *%a_var)
- %a_i8 = bitcast %a* %a_var to i8*
- %b_i8 = bitcast %b* %b_var to i8*
- call void @llvm.memcpy.i32(i8* %b_i8, i8* %a_i8, i32 4, i32 4)
- %tmp1 = getelementptr %b* %b_var, i32 0, i32 0
- %tmp2 = load float* %tmp1
- ret float %tmp2
-}
Removed: llvm/trunk/test/Transforms/GVN/form-memset.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/form-memset.ll?rev=49418&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/GVN/form-memset.ll (original)
+++ llvm/trunk/test/Transforms/GVN/form-memset.ll (removed)
@@ -1,55 +0,0 @@
-; RUN: llvm-as < %s | opt -gvn -form-memset-from-stores | llvm-dis | not grep store
-; RUN: llvm-as < %s | opt -gvn -form-memset-from-stores | llvm-dis | grep {call.*llvm.memset}
-
-; All the stores in this example should be merged into a single memset.
-
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
-target triple = "i386-apple-darwin8"
-
-define void @foo(i8 signext %c) nounwind {
-entry:
- %x = alloca [19 x i8] ; <[19 x i8]*> [#uses=20]
- %tmp = getelementptr [19 x i8]* %x, i32 0, i32 0 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp, align 1
- %tmp5 = getelementptr [19 x i8]* %x, i32 0, i32 1 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp5, align 1
- %tmp9 = getelementptr [19 x i8]* %x, i32 0, i32 2 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp9, align 1
- %tmp13 = getelementptr [19 x i8]* %x, i32 0, i32 3 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp13, align 1
- %tmp17 = getelementptr [19 x i8]* %x, i32 0, i32 4 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp17, align 1
- %tmp21 = getelementptr [19 x i8]* %x, i32 0, i32 5 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp21, align 1
- %tmp25 = getelementptr [19 x i8]* %x, i32 0, i32 6 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp25, align 1
- %tmp29 = getelementptr [19 x i8]* %x, i32 0, i32 7 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp29, align 1
- %tmp33 = getelementptr [19 x i8]* %x, i32 0, i32 8 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp33, align 1
- %tmp37 = getelementptr [19 x i8]* %x, i32 0, i32 9 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp37, align 1
- %tmp41 = getelementptr [19 x i8]* %x, i32 0, i32 10 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp41, align 1
- %tmp45 = getelementptr [19 x i8]* %x, i32 0, i32 11 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp45, align 1
- %tmp49 = getelementptr [19 x i8]* %x, i32 0, i32 12 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp49, align 1
- %tmp53 = getelementptr [19 x i8]* %x, i32 0, i32 13 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp53, align 1
- %tmp57 = getelementptr [19 x i8]* %x, i32 0, i32 14 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp57, align 1
- %tmp61 = getelementptr [19 x i8]* %x, i32 0, i32 15 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp61, align 1
- %tmp65 = getelementptr [19 x i8]* %x, i32 0, i32 16 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp65, align 1
- %tmp69 = getelementptr [19 x i8]* %x, i32 0, i32 17 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp69, align 1
- %tmp73 = getelementptr [19 x i8]* %x, i32 0, i32 18 ; <i8*> [#uses=1]
- store i8 %c, i8* %tmp73, align 1
- %tmp76 = call i32 (...)* @bar( [19 x i8]* %x ) nounwind ; <i32> [#uses=0]
- ret void
-}
-
-declare i32 @bar(...)
-
Removed: llvm/trunk/test/Transforms/GVN/form-memset2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/form-memset2.ll?rev=49418&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/GVN/form-memset2.ll (original)
+++ llvm/trunk/test/Transforms/GVN/form-memset2.ll (removed)
@@ -1,99 +0,0 @@
-; RUN: llvm-as < %s | opt -gvn -form-memset-from-stores | llvm-dis | not grep store
-; RUN: llvm-as < %s | opt -gvn -form-memset-from-stores | llvm-dis | grep {call.*llvm.memset} | count 3
-
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
-target triple = "i386-apple-darwin8"
- %struct.MV = type { i16, i16 }
-
-define i32 @t() nounwind {
-entry:
- %ref_idx = alloca [8 x i8] ; <[8 x i8]*> [#uses=8]
- %left_mvd = alloca [8 x %struct.MV] ; <[8 x %struct.MV]*> [#uses=17]
- %up_mvd = alloca [8 x %struct.MV] ; <[8 x %struct.MV]*> [#uses=17]
- %tmp20 = getelementptr [8 x i8]* %ref_idx, i32 0, i32 7 ; <i8*> [#uses=1]
- store i8 -1, i8* %tmp20, align 1
- %tmp23 = getelementptr [8 x i8]* %ref_idx, i32 0, i32 6 ; <i8*> [#uses=1]
- store i8 -1, i8* %tmp23, align 1
- %tmp26 = getelementptr [8 x i8]* %ref_idx, i32 0, i32 5 ; <i8*> [#uses=1]
- store i8 -1, i8* %tmp26, align 1
- %tmp29 = getelementptr [8 x i8]* %ref_idx, i32 0, i32 4 ; <i8*> [#uses=1]
- store i8 -1, i8* %tmp29, align 1
- %tmp32 = getelementptr [8 x i8]* %ref_idx, i32 0, i32 3 ; <i8*> [#uses=1]
- store i8 -1, i8* %tmp32, align 1
- %tmp35 = getelementptr [8 x i8]* %ref_idx, i32 0, i32 2 ; <i8*> [#uses=1]
- store i8 -1, i8* %tmp35, align 1
- %tmp38 = getelementptr [8 x i8]* %ref_idx, i32 0, i32 1 ; <i8*> [#uses=1]
- store i8 -1, i8* %tmp38, align 1
- %tmp41 = getelementptr [8 x i8]* %ref_idx, i32 0, i32 0 ; <i8*> [#uses=2]
- store i8 -1, i8* %tmp41, align 1
- %tmp43 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 7, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp43, align 2
- %tmp46 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 7, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp46, align 2
- %tmp57 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 6, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp57, align 2
- %tmp60 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 6, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp60, align 2
- %tmp71 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 5, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp71, align 2
- %tmp74 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 5, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp74, align 2
- %tmp85 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 4, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp85, align 2
- %tmp88 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 4, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp88, align 2
- %tmp99 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 3, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp99, align 2
- %tmp102 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 3, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp102, align 2
- %tmp113 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 2, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp113, align 2
- %tmp116 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 2, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp116, align 2
- %tmp127 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 1, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp127, align 2
- %tmp130 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 1, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp130, align 2
- %tmp141 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 0, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp141, align 8
- %tmp144 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 0, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp144, align 2
- %tmp148 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 7, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp148, align 2
- %tmp151 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 7, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp151, align 2
- %tmp162 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 6, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp162, align 2
- %tmp165 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 6, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp165, align 2
- %tmp176 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 5, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp176, align 2
- %tmp179 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 5, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp179, align 2
- %tmp190 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 4, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp190, align 2
- %tmp193 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 4, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp193, align 2
- %tmp204 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 3, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp204, align 2
- %tmp207 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 3, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp207, align 2
- %tmp218 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 2, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp218, align 2
- %tmp221 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 2, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp221, align 2
- %tmp232 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 1, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp232, align 2
- %tmp235 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 1, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp235, align 2
- %tmp246 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 0, i32 0 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp246, align 8
- %tmp249 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 0, i32 1 ; <i16*> [#uses=1]
- store i16 0, i16* %tmp249, align 2
- %up_mvd252 = getelementptr [8 x %struct.MV]* %up_mvd, i32 0, i32 0 ; <%struct.MV*> [#uses=1]
- %left_mvd253 = getelementptr [8 x %struct.MV]* %left_mvd, i32 0, i32 0 ; <%struct.MV*> [#uses=1]
- call void @foo( %struct.MV* %up_mvd252, %struct.MV* %left_mvd253, i8* %tmp41 ) nounwind
- ret i32 undef
-}
-
-declare void @foo(%struct.MV*, %struct.MV*, i8*)
Removed: llvm/trunk/test/Transforms/GVN/memcpy.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/memcpy.ll?rev=49418&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/GVN/memcpy.ll (original)
+++ llvm/trunk/test/Transforms/GVN/memcpy.ll (removed)
@@ -1,22 +0,0 @@
-; RUN: llvm-as < %s | opt -gvn -dse | llvm-dis | grep {call.*memcpy} | count 1
-
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
-target triple = "i686-apple-darwin9"
-
-define void @ccosl({ x86_fp80, x86_fp80 }* sret %agg.result, x86_fp80 %z.0, x86_fp80 %z.1) nounwind {
-entry:
- %tmp2 = alloca { x86_fp80, x86_fp80 } ; <{ x86_fp80, x86_fp80 }*> [#uses=1]
- %memtmp = alloca { x86_fp80, x86_fp80 }, align 16 ; <{ x86_fp80, x86_fp80 }*> [#uses=2]
- %tmp5 = sub x86_fp80 0xK80000000000000000000, %z.1 ; <x86_fp80> [#uses=1]
- call void @ccoshl( { x86_fp80, x86_fp80 }* sret %memtmp, x86_fp80 %tmp5, x86_fp80 %z.0 ) nounwind
- %tmp219 = bitcast { x86_fp80, x86_fp80 }* %tmp2 to i8* ; <i8*> [#uses=2]
- %memtmp20 = bitcast { x86_fp80, x86_fp80 }* %memtmp to i8* ; <i8*> [#uses=1]
- call void @llvm.memcpy.i32( i8* %tmp219, i8* %memtmp20, i32 32, i32 16 )
- %agg.result21 = bitcast { x86_fp80, x86_fp80 }* %agg.result to i8* ; <i8*> [#uses=1]
- call void @llvm.memcpy.i32( i8* %agg.result21, i8* %tmp219, i32 32, i32 16 )
- ret void
-}
-
-declare void @ccoshl({ x86_fp80, x86_fp80 }* sret , x86_fp80, x86_fp80) nounwind
-
-declare void @llvm.memcpy.i32(i8*, i8*, i32, i32) nounwind
Removed: llvm/trunk/test/Transforms/GVN/sret.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/sret.ll?rev=49418&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/GVN/sret.ll (original)
+++ llvm/trunk/test/Transforms/GVN/sret.ll (removed)
@@ -1,28 +0,0 @@
-; RUN: llvm-as < %s | opt -gvn | llvm-dis | not grep {call.*memcpy}
-
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
-target triple = "i686-apple-darwin9"
-
-define void @ccosl({ x86_fp80, x86_fp80 }* noalias sret %agg.result, { x86_fp80, x86_fp80 }* byval %z) nounwind {
-entry:
- %iz = alloca { x86_fp80, x86_fp80 } ; <{ x86_fp80, x86_fp80 }*> [#uses=3]
- %memtmp = alloca { x86_fp80, x86_fp80 }, align 16 ; <{ x86_fp80, x86_fp80 }*> [#uses=2]
- %tmp1 = getelementptr { x86_fp80, x86_fp80 }* %z, i32 0, i32 1 ; <x86_fp80*> [#uses=1]
- %tmp2 = load x86_fp80* %tmp1, align 16 ; <x86_fp80> [#uses=1]
- %tmp3 = sub x86_fp80 0xK80000000000000000000, %tmp2 ; <x86_fp80> [#uses=1]
- %tmp4 = getelementptr { x86_fp80, x86_fp80 }* %iz, i32 0, i32 1 ; <x86_fp80*> [#uses=1]
- %real = getelementptr { x86_fp80, x86_fp80 }* %iz, i32 0, i32 0 ; <x86_fp80*> [#uses=1]
- %tmp7 = getelementptr { x86_fp80, x86_fp80 }* %z, i32 0, i32 0 ; <x86_fp80*> [#uses=1]
- %tmp8 = load x86_fp80* %tmp7, align 16 ; <x86_fp80> [#uses=1]
- store x86_fp80 %tmp3, x86_fp80* %real, align 16
- store x86_fp80 %tmp8, x86_fp80* %tmp4, align 16
- call void @ccoshl( { x86_fp80, x86_fp80 }* noalias sret %memtmp, { x86_fp80, x86_fp80 }* byval %iz ) nounwind
- %memtmp14 = bitcast { x86_fp80, x86_fp80 }* %memtmp to i8* ; <i8*> [#uses=1]
- %agg.result15 = bitcast { x86_fp80, x86_fp80 }* %agg.result to i8* ; <i8*> [#uses=1]
- call void @llvm.memcpy.i32( i8* %agg.result15, i8* %memtmp14, i32 32, i32 16 )
- ret void
-}
-
-declare void @ccoshl({ x86_fp80, x86_fp80 }* noalias sret , { x86_fp80, x86_fp80 }* byval ) nounwind
-
-declare void @llvm.memcpy.i32(i8*, i8*, i32, i32) nounwind
Copied: llvm/trunk/test/Transforms/MemCpyOpt/2008-02-24-MultipleUseofSRet.ll (from r49415, llvm/trunk/test/Transforms/GVN/2008-02-24-MultipleUseofSRet.ll)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MemCpyOpt/2008-02-24-MultipleUseofSRet.ll?p2=llvm/trunk/test/Transforms/MemCpyOpt/2008-02-24-MultipleUseofSRet.ll&p1=llvm/trunk/test/Transforms/GVN/2008-02-24-MultipleUseofSRet.ll&r1=49415&r2=49419&rev=49419&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/2008-02-24-MultipleUseofSRet.ll (original)
+++ llvm/trunk/test/Transforms/MemCpyOpt/2008-02-24-MultipleUseofSRet.ll Wed Apr 9 03:23:16 2008
@@ -1,4 +1,4 @@
-; RUN: llvm-as < %s | opt -gvn -dse | llvm-dis | grep {call.*initialize} | not grep memtmp
+; RUN: llvm-as < %s | opt -memcpyopt -dse | llvm-dis | grep {call.*initialize} | not grep memtmp
; PR2077
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
Copied: llvm/trunk/test/Transforms/MemCpyOpt/2008-03-13-ReturnSlotBitcast.ll (from r49415, llvm/trunk/test/Transforms/GVN/2008-03-13-ReturnSlotBitcast.ll)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MemCpyOpt/2008-03-13-ReturnSlotBitcast.ll?p2=llvm/trunk/test/Transforms/MemCpyOpt/2008-03-13-ReturnSlotBitcast.ll&p1=llvm/trunk/test/Transforms/GVN/2008-03-13-ReturnSlotBitcast.ll&r1=49415&r2=49419&rev=49419&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/2008-03-13-ReturnSlotBitcast.ll (original)
+++ llvm/trunk/test/Transforms/MemCpyOpt/2008-03-13-ReturnSlotBitcast.ll Wed Apr 9 03:23:16 2008
@@ -1,4 +1,4 @@
-; RUN: llvm-as < %s | opt -gvn | llvm-dis | not grep {call.*memcpy.}
+; RUN: llvm-as < %s | opt -memcpyopt | llvm-dis | not grep {call.*memcpy.}
%a = type { i32 }
%b = type { float }
Added: llvm/trunk/test/Transforms/MemCpyOpt/dg.exp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MemCpyOpt/dg.exp?rev=49419&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/MemCpyOpt/dg.exp (added)
+++ llvm/trunk/test/Transforms/MemCpyOpt/dg.exp Wed Apr 9 03:23:16 2008
@@ -0,0 +1,3 @@
+load_lib llvm.exp
+
+RunLLVMTests [lsort [glob -nocomplain $srcdir/$subdir/*.{ll,llx,c,cpp,tr}]]
Copied: llvm/trunk/test/Transforms/MemCpyOpt/form-memset.ll (from r49415, llvm/trunk/test/Transforms/GVN/form-memset.ll)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MemCpyOpt/form-memset.ll?p2=llvm/trunk/test/Transforms/MemCpyOpt/form-memset.ll&p1=llvm/trunk/test/Transforms/GVN/form-memset.ll&r1=49415&r2=49419&rev=49419&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/form-memset.ll (original)
+++ llvm/trunk/test/Transforms/MemCpyOpt/form-memset.ll Wed Apr 9 03:23:16 2008
@@ -1,5 +1,5 @@
-; RUN: llvm-as < %s | opt -gvn -form-memset-from-stores | llvm-dis | not grep store
-; RUN: llvm-as < %s | opt -gvn -form-memset-from-stores | llvm-dis | grep {call.*llvm.memset}
+; RUN: llvm-as < %s | opt -memcpyopt -form-memset-from-stores | llvm-dis | not grep store
+; RUN: llvm-as < %s | opt -memcpyopt -form-memset-from-stores | llvm-dis | grep {call.*llvm.memset}
; All the stores in this example should be merged into a single memset.
Copied: llvm/trunk/test/Transforms/MemCpyOpt/form-memset2.ll (from r49415, llvm/trunk/test/Transforms/GVN/form-memset2.ll)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MemCpyOpt/form-memset2.ll?p2=llvm/trunk/test/Transforms/MemCpyOpt/form-memset2.ll&p1=llvm/trunk/test/Transforms/GVN/form-memset2.ll&r1=49415&r2=49419&rev=49419&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/form-memset2.ll (original)
+++ llvm/trunk/test/Transforms/MemCpyOpt/form-memset2.ll Wed Apr 9 03:23:16 2008
@@ -1,5 +1,5 @@
-; RUN: llvm-as < %s | opt -gvn -form-memset-from-stores | llvm-dis | not grep store
-; RUN: llvm-as < %s | opt -gvn -form-memset-from-stores | llvm-dis | grep {call.*llvm.memset} | count 3
+; RUN: llvm-as < %s | opt -memcpyopt -form-memset-from-stores | llvm-dis | not grep store
+; RUN: llvm-as < %s | opt -memcpyopt -form-memset-from-stores | llvm-dis | grep {call.*llvm.memset} | count 3
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin8"
Copied: llvm/trunk/test/Transforms/MemCpyOpt/memcpy.ll (from r49415, llvm/trunk/test/Transforms/GVN/memcpy.ll)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MemCpyOpt/memcpy.ll?p2=llvm/trunk/test/Transforms/MemCpyOpt/memcpy.ll&p1=llvm/trunk/test/Transforms/GVN/memcpy.ll&r1=49415&r2=49419&rev=49419&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/memcpy.ll (original)
+++ llvm/trunk/test/Transforms/MemCpyOpt/memcpy.ll Wed Apr 9 03:23:16 2008
@@ -1,4 +1,4 @@
-; RUN: llvm-as < %s | opt -gvn -dse | llvm-dis | grep {call.*memcpy} | count 1
+; RUN: llvm-as < %s | opt -memcpyopt -dse | llvm-dis | grep {call.*memcpy} | count 1
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i686-apple-darwin9"
Copied: llvm/trunk/test/Transforms/MemCpyOpt/sret.ll (from r49415, llvm/trunk/test/Transforms/GVN/sret.ll)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MemCpyOpt/sret.ll?p2=llvm/trunk/test/Transforms/MemCpyOpt/sret.ll&p1=llvm/trunk/test/Transforms/GVN/sret.ll&r1=49415&r2=49419&rev=49419&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/sret.ll (original)
+++ llvm/trunk/test/Transforms/MemCpyOpt/sret.ll Wed Apr 9 03:23:16 2008
@@ -1,4 +1,4 @@
-; RUN: llvm-as < %s | opt -gvn | llvm-dis | not grep {call.*memcpy}
+; RUN: llvm-as < %s | opt -memcpyopt | llvm-dis | not grep {call.*memcpy}
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i686-apple-darwin9"
Modified: llvm/trunk/tools/llvm-ld/Optimize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-ld/Optimize.cpp?rev=49419&r1=49418&r2=49419&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-ld/Optimize.cpp (original)
+++ llvm/trunk/tools/llvm-ld/Optimize.cpp Wed Apr 9 03:23:16 2008
@@ -169,6 +169,7 @@
addPass(Passes, createGlobalsModRefPass()); // IP alias analysis
addPass(Passes, createLICMPass()); // Hoist loop invariants
+ addPass(Passes, createMemCpyOptPass()); // Remove dead memcpy's
addPass(Passes, createGVNPass()); // Remove redundancies
addPass(Passes, createDeadStoreEliminationPass()); // Nuke dead stores
Modified: llvm/trunk/tools/opt/opt.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/opt/opt.cpp?rev=49419&r1=49418&r2=49419&view=diff
==============================================================================
--- llvm/trunk/tools/opt/opt.cpp (original)
+++ llvm/trunk/tools/opt/opt.cpp Wed Apr 9 03:23:16 2008
@@ -282,6 +282,7 @@
addPass(PM, createIndVarSimplifyPass()); // Canonicalize indvars
addPass(PM, createLoopUnrollPass()); // Unroll small loops
addPass(PM, createInstructionCombiningPass()); // Clean up after the unroller
+ addPass(PM, createMemCpyOptPass()); // Remove unneeded memcpy's
addPass(PM, createGVNPass()); // Remove redundancies
addPass(PM, createSCCPPass()); // Constant prop with SCCP
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