//
//===----------------------------------------------------------------------===//
//
+// \file
// Lower aggregate copies, memset, memcpy, memmov intrinsics into loops when
// the size is large or is not a compile-time constant.
//
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
-#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
char NVPTXLowerAggrCopies::ID = 0;
// Lower memcpy to loop.
-void convertMemCpyToLoop(Instruction *splitAt, Value *srcAddr, Value *dstAddr,
- Value *len, bool srcVolatile, bool dstVolatile,
- LLVMContext &Context, Function &F) {
- Type *indType = len->getType();
+void convertMemCpyToLoop(Instruction *ConvertedInst, Value *SrcAddr,
+ Value *DstAddr, Value *CopyLen, bool SrcIsVolatile,
+ bool DstIsVolatile, LLVMContext &Context,
+ Function &F) {
+ Type *TypeOfCopyLen = CopyLen->getType();
- BasicBlock *origBB = splitAt->getParent();
- BasicBlock *newBB = splitAt->getParent()->splitBasicBlock(splitAt, "split");
- BasicBlock *loopBB = BasicBlock::Create(Context, "loadstoreloop", &F, newBB);
+ BasicBlock *OrigBB = ConvertedInst->getParent();
+ BasicBlock *NewBB =
+ ConvertedInst->getParent()->splitBasicBlock(ConvertedInst, "split");
+ BasicBlock *LoopBB = BasicBlock::Create(Context, "loadstoreloop", &F, NewBB);
- origBB->getTerminator()->setSuccessor(0, loopBB);
- IRBuilder<> builder(origBB, origBB->getTerminator());
+ OrigBB->getTerminator()->setSuccessor(0, LoopBB);
+ IRBuilder<> Builder(OrigBB, OrigBB->getTerminator());
- // srcAddr and dstAddr are expected to be pointer types,
+ // SrcAddr and DstAddr are expected to be pointer types,
// so no check is made here.
- unsigned srcAS = cast<PointerType>(srcAddr->getType())->getAddressSpace();
- unsigned dstAS = cast<PointerType>(dstAddr->getType())->getAddressSpace();
+ unsigned SrcAS = cast<PointerType>(SrcAddr->getType())->getAddressSpace();
+ unsigned DstAS = cast<PointerType>(DstAddr->getType())->getAddressSpace();
// Cast pointers to (char *)
- srcAddr = builder.CreateBitCast(srcAddr, Type::getInt8PtrTy(Context, srcAS));
- dstAddr = builder.CreateBitCast(dstAddr, Type::getInt8PtrTy(Context, dstAS));
+ SrcAddr = Builder.CreateBitCast(SrcAddr, Builder.getInt8PtrTy(SrcAS));
+ DstAddr = Builder.CreateBitCast(DstAddr, Builder.getInt8PtrTy(DstAS));
- IRBuilder<> loop(loopBB);
- // The loop index (ind) is a phi node.
- PHINode *ind = loop.CreatePHI(indType, 0);
- // Incoming value for ind is 0
- ind->addIncoming(ConstantInt::get(indType, 0), origBB);
+ IRBuilder<> LoopBuilder(LoopBB);
+ PHINode *LoopIndex = LoopBuilder.CreatePHI(TypeOfCopyLen, 0);
+ LoopIndex->addIncoming(ConstantInt::get(TypeOfCopyLen, 0), OrigBB);
- // load from srcAddr+ind
+ // load from SrcAddr+LoopIndex
// TODO: we can leverage the align parameter of llvm.memcpy for more efficient
// word-sized loads and stores.
- Value *val = loop.CreateLoad(loop.CreateGEP(loop.getInt8Ty(), srcAddr, ind),
- srcVolatile);
- // store at dstAddr+ind
- loop.CreateStore(val, loop.CreateGEP(loop.getInt8Ty(), dstAddr, ind),
- dstVolatile);
-
- // The value for ind coming from backedge is (ind + 1)
- Value *newind = loop.CreateAdd(ind, ConstantInt::get(indType, 1));
- ind->addIncoming(newind, loopBB);
-
- loop.CreateCondBr(loop.CreateICmpULT(newind, len), loopBB, newBB);
+ Value *Element = LoopBuilder.CreateLoad(
+ LoopBuilder.CreateGEP(LoopBuilder.getInt8Ty(), SrcAddr, LoopIndex),
+ SrcIsVolatile);
+ // store at DstAddr+LoopIndex
+ LoopBuilder.CreateStore(
+ Element,
+ LoopBuilder.CreateGEP(LoopBuilder.getInt8Ty(), DstAddr, LoopIndex),
+ DstIsVolatile);
+
+ // The value for LoopIndex coming from backedge is (LoopIndex + 1)
+ Value *NewIndex =
+ LoopBuilder.CreateAdd(LoopIndex, ConstantInt::get(TypeOfCopyLen, 1));
+ LoopIndex->addIncoming(NewIndex, LoopBB);
+
+ LoopBuilder.CreateCondBr(LoopBuilder.CreateICmpULT(NewIndex, CopyLen), LoopBB,
+ NewBB);
}
// Lower memmove to IR. memmove is required to correctly copy overlapping memory
// }
// return dst;
// }
-void convertMemMoveToLoop(Instruction *splitAt, Value *srcAddr, Value *dstAddr,
- Value *len, bool srcVolatile, bool dstVolatile,
- LLVMContext &Context, Function &F) {
- Type *TypeOfLen = len->getType();
- BasicBlock *OrigBB = splitAt->getParent();
+void convertMemMoveToLoop(Instruction *ConvertedInst, Value *SrcAddr,
+ Value *DstAddr, Value *CopyLen, bool SrcIsVolatile,
+ bool DstIsVolatile, LLVMContext &Context,
+ Function &F) {
+ Type *TypeOfCopyLen = CopyLen->getType();
+ BasicBlock *OrigBB = ConvertedInst->getParent();
// Create the a comparison of src and dst, based on which we jump to either
// the forward-copy part of the function (if src >= dst) or the backwards-copy
// SplitBlockAndInsertIfThenElse conveniently creates the basic if-then-else
// structure. Its block terminators (unconditional branches) are replaced by
// the appropriate conditional branches when the loop is built.
- ICmpInst *PtrCompare = new ICmpInst(splitAt, ICmpInst::ICMP_ULT, srcAddr,
- dstAddr, "compare_src_dst");
+ ICmpInst *PtrCompare = new ICmpInst(ConvertedInst, ICmpInst::ICMP_ULT,
+ SrcAddr, DstAddr, "compare_src_dst");
TerminatorInst *ThenTerm, *ElseTerm;
- SplitBlockAndInsertIfThenElse(PtrCompare, splitAt, &ThenTerm, &ElseTerm);
+ SplitBlockAndInsertIfThenElse(PtrCompare, ConvertedInst, &ThenTerm,
+ &ElseTerm);
// Each part of the function consists of two blocks:
// copy_backwards: used to skip the loop when n == 0
CopyBackwardsBB->setName("copy_backwards");
BasicBlock *CopyForwardBB = ElseTerm->getParent();
CopyForwardBB->setName("copy_forward");
- BasicBlock *ExitBB = splitAt->getParent();
+ BasicBlock *ExitBB = ConvertedInst->getParent();
ExitBB->setName("memmove_done");
// Initial comparison of n == 0 that lets us skip the loops altogether. Shared
// between both backwards and forward copy clauses.
ICmpInst *CompareN =
- new ICmpInst(OrigBB->getTerminator(), ICmpInst::ICMP_EQ, len,
- ConstantInt::get(TypeOfLen, 0), "compare_n_to_0");
+ new ICmpInst(OrigBB->getTerminator(), ICmpInst::ICMP_EQ, CopyLen,
+ ConstantInt::get(TypeOfCopyLen, 0), "compare_n_to_0");
// Copying backwards.
BasicBlock *LoopBB =
BasicBlock::Create(Context, "copy_backwards_loop", &F, CopyForwardBB);
IRBuilder<> LoopBuilder(LoopBB);
- PHINode *LoopPhi = LoopBuilder.CreatePHI(TypeOfLen, 0);
+ PHINode *LoopPhi = LoopBuilder.CreatePHI(TypeOfCopyLen, 0);
Value *IndexPtr = LoopBuilder.CreateSub(
- LoopPhi, ConstantInt::get(TypeOfLen, 1), "index_ptr");
+ LoopPhi, ConstantInt::get(TypeOfCopyLen, 1), "index_ptr");
Value *Element = LoopBuilder.CreateLoad(
- LoopBuilder.CreateInBoundsGEP(srcAddr, IndexPtr), "element");
+ LoopBuilder.CreateInBoundsGEP(SrcAddr, IndexPtr), "element");
LoopBuilder.CreateStore(Element,
- LoopBuilder.CreateInBoundsGEP(dstAddr, IndexPtr));
+ LoopBuilder.CreateInBoundsGEP(DstAddr, IndexPtr));
LoopBuilder.CreateCondBr(
- LoopBuilder.CreateICmpEQ(IndexPtr, ConstantInt::get(TypeOfLen, 0)),
+ LoopBuilder.CreateICmpEQ(IndexPtr, ConstantInt::get(TypeOfCopyLen, 0)),
ExitBB, LoopBB);
LoopPhi->addIncoming(IndexPtr, LoopBB);
- LoopPhi->addIncoming(len, CopyBackwardsBB);
+ LoopPhi->addIncoming(CopyLen, CopyBackwardsBB);
BranchInst::Create(ExitBB, LoopBB, CompareN, ThenTerm);
ThenTerm->eraseFromParent();
BasicBlock *FwdLoopBB =
BasicBlock::Create(Context, "copy_forward_loop", &F, ExitBB);
IRBuilder<> FwdLoopBuilder(FwdLoopBB);
- PHINode *FwdCopyPhi = FwdLoopBuilder.CreatePHI(TypeOfLen, 0, "index_ptr");
+ PHINode *FwdCopyPhi = FwdLoopBuilder.CreatePHI(TypeOfCopyLen, 0, "index_ptr");
Value *FwdElement = FwdLoopBuilder.CreateLoad(
- FwdLoopBuilder.CreateInBoundsGEP(srcAddr, FwdCopyPhi), "element");
+ FwdLoopBuilder.CreateInBoundsGEP(SrcAddr, FwdCopyPhi), "element");
FwdLoopBuilder.CreateStore(
- FwdElement, FwdLoopBuilder.CreateInBoundsGEP(dstAddr, FwdCopyPhi));
+ FwdElement, FwdLoopBuilder.CreateInBoundsGEP(DstAddr, FwdCopyPhi));
Value *FwdIndexPtr = FwdLoopBuilder.CreateAdd(
- FwdCopyPhi, ConstantInt::get(TypeOfLen, 1), "index_increment");
- FwdLoopBuilder.CreateCondBr(FwdLoopBuilder.CreateICmpEQ(FwdIndexPtr, len),
+ FwdCopyPhi, ConstantInt::get(TypeOfCopyLen, 1), "index_increment");
+ FwdLoopBuilder.CreateCondBr(FwdLoopBuilder.CreateICmpEQ(FwdIndexPtr, CopyLen),
ExitBB, FwdLoopBB);
FwdCopyPhi->addIncoming(FwdIndexPtr, FwdLoopBB);
- FwdCopyPhi->addIncoming(ConstantInt::get(TypeOfLen, 0), CopyForwardBB);
+ FwdCopyPhi->addIncoming(ConstantInt::get(TypeOfCopyLen, 0), CopyForwardBB);
BranchInst::Create(ExitBB, FwdLoopBB, CompareN, ElseTerm);
ElseTerm->eraseFromParent();
}
// Lower memset to loop.
-void convertMemSetToLoop(Instruction *splitAt, Value *dstAddr, Value *len,
- Value *val, LLVMContext &Context, Function &F) {
- BasicBlock *origBB = splitAt->getParent();
- BasicBlock *newBB = splitAt->getParent()->splitBasicBlock(splitAt, "split");
- BasicBlock *loopBB = BasicBlock::Create(Context, "loadstoreloop", &F, newBB);
+void convertMemSetToLoop(Instruction *ConvertedInst, Value *DstAddr,
+ Value *CopyLen, Value *SetValue, LLVMContext &Context,
+ Function &F) {
+ BasicBlock *OrigBB = ConvertedInst->getParent();
+ BasicBlock *NewBB =
+ ConvertedInst->getParent()->splitBasicBlock(ConvertedInst, "split");
+ BasicBlock *LoopBB = BasicBlock::Create(Context, "loadstoreloop", &F, NewBB);
- origBB->getTerminator()->setSuccessor(0, loopBB);
- IRBuilder<> builder(origBB, origBB->getTerminator());
-
- unsigned dstAS = cast<PointerType>(dstAddr->getType())->getAddressSpace();
+ OrigBB->getTerminator()->setSuccessor(0, LoopBB);
+ IRBuilder<> Builder(OrigBB, OrigBB->getTerminator());
// Cast pointer to the type of value getting stored
- dstAddr =
- builder.CreateBitCast(dstAddr, PointerType::get(val->getType(), dstAS));
+ unsigned dstAS = cast<PointerType>(DstAddr->getType())->getAddressSpace();
+ DstAddr = Builder.CreateBitCast(DstAddr,
+ PointerType::get(SetValue->getType(), dstAS));
- IRBuilder<> loop(loopBB);
- PHINode *ind = loop.CreatePHI(len->getType(), 0);
- ind->addIncoming(ConstantInt::get(len->getType(), 0), origBB);
+ IRBuilder<> LoopBuilder(LoopBB);
+ PHINode *LoopIndex = LoopBuilder.CreatePHI(CopyLen->getType(), 0);
+ LoopIndex->addIncoming(ConstantInt::get(CopyLen->getType(), 0), OrigBB);
- loop.CreateStore(val, loop.CreateGEP(val->getType(), dstAddr, ind), false);
+ LoopBuilder.CreateStore(
+ SetValue, LoopBuilder.CreateGEP(SetValue->getType(), DstAddr, LoopIndex),
+ false);
- Value *newind = loop.CreateAdd(ind, ConstantInt::get(len->getType(), 1));
- ind->addIncoming(newind, loopBB);
+ Value *NewIndex =
+ LoopBuilder.CreateAdd(LoopIndex, ConstantInt::get(CopyLen->getType(), 1));
+ LoopIndex->addIncoming(NewIndex, LoopBB);
- loop.CreateCondBr(loop.CreateICmpULT(newind, len), loopBB, newBB);
+ LoopBuilder.CreateCondBr(LoopBuilder.CreateICmpULT(NewIndex, CopyLen), LoopBB,
+ NewBB);
}
bool NVPTXLowerAggrCopies::runOnFunction(Function &F) {
- SmallVector<LoadInst *, 4> aggrLoads;
+ SmallVector<LoadInst *, 4> AggrLoads;
SmallVector<MemIntrinsic *, 4> MemCalls;
const DataLayout &DL = F.getParent()->getDataLayout();
for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;
++II) {
- if (LoadInst *load = dyn_cast<LoadInst>(II)) {
- if (!load->hasOneUse())
+ if (LoadInst *LI = dyn_cast<LoadInst>(II)) {
+ if (!LI->hasOneUse())
continue;
- if (DL.getTypeStoreSize(load->getType()) < MaxAggrCopySize)
+ if (DL.getTypeStoreSize(LI->getType()) < MaxAggrCopySize)
continue;
- User *use = load->user_back();
- if (StoreInst *store = dyn_cast<StoreInst>(use)) {
- if (store->getOperand(0) != load)
+ if (StoreInst *SI = dyn_cast<StoreInst>(LI->user_back())) {
+ if (SI->getOperand(0) != LI)
continue;
- aggrLoads.push_back(load);
+ AggrLoads.push_back(LI);
}
} else if (MemIntrinsic *IntrCall = dyn_cast<MemIntrinsic>(II)) {
// Convert intrinsic calls with variable size or with constant size
}
}
- if (aggrLoads.size() == 0 && MemCalls.size() == 0) {
+ if (AggrLoads.size() == 0 && MemCalls.size() == 0) {
return false;
}
//
// Do the transformation of an aggr load/copy/set to a loop
//
- for (LoadInst *load : aggrLoads) {
- StoreInst *store = dyn_cast<StoreInst>(*load->user_begin());
- Value *srcAddr = load->getOperand(0);
- Value *dstAddr = store->getOperand(1);
- unsigned numLoads = DL.getTypeStoreSize(load->getType());
- Value *len = ConstantInt::get(Type::getInt32Ty(Context), numLoads);
-
- convertMemCpyToLoop(store, srcAddr, dstAddr, len, load->isVolatile(),
- store->isVolatile(), Context, F);
-
- store->eraseFromParent();
- load->eraseFromParent();
+ for (LoadInst *LI : AggrLoads) {
+ StoreInst *SI = dyn_cast<StoreInst>(*LI->user_begin());
+ Value *SrcAddr = LI->getOperand(0);
+ Value *DstAddr = SI->getOperand(1);
+ unsigned NumLoads = DL.getTypeStoreSize(LI->getType());
+ Value *CopyLen = ConstantInt::get(Type::getInt32Ty(Context), NumLoads);
+
+ convertMemCpyToLoop(/* ConvertedInst */ SI,
+ /* SrcAddr */ SrcAddr, /* DstAddr */ DstAddr,
+ /* CopyLen */ CopyLen,
+ /* SrcIsVolatile */ LI->isVolatile(),
+ /* DstIsVolatile */ SI->isVolatile(),
+ /* Context */ Context,
+ /* Function F */ F);
+
+ SI->eraseFromParent();
+ LI->eraseFromParent();
}
// Transform mem* intrinsic calls.
for (MemIntrinsic *MemCall : MemCalls) {
if (MemCpyInst *Memcpy = dyn_cast<MemCpyInst>(MemCall)) {
- convertMemCpyToLoop(/* splitAt */ Memcpy,
- /* srcAddr */ Memcpy->getRawSource(),
- /* dstAddr */ Memcpy->getRawDest(),
- /* len */ Memcpy->getLength(),
- /* srcVolatile */ Memcpy->isVolatile(),
- /* dstVolatile */ Memcpy->isVolatile(),
+ convertMemCpyToLoop(/* ConvertedInst */ Memcpy,
+ /* SrcAddr */ Memcpy->getRawSource(),
+ /* DstAddr */ Memcpy->getRawDest(),
+ /* CopyLen */ Memcpy->getLength(),
+ /* SrcIsVolatile */ Memcpy->isVolatile(),
+ /* DstIsVolatile */ Memcpy->isVolatile(),
/* Context */ Context,
/* Function F */ F);
} else if (MemMoveInst *Memmove = dyn_cast<MemMoveInst>(MemCall)) {
- convertMemMoveToLoop(/* splitAt */ Memmove,
- /* srcAddr */ Memmove->getRawSource(),
- /* dstAddr */ Memmove->getRawDest(),
- /* len */ Memmove->getLength(),
- /* srcVolatile */ Memmove->isVolatile(),
- /* dstVolatile */ Memmove->isVolatile(),
+ convertMemMoveToLoop(/* ConvertedInst */ Memmove,
+ /* SrcAddr */ Memmove->getRawSource(),
+ /* DstAddr */ Memmove->getRawDest(),
+ /* CopyLen */ Memmove->getLength(),
+ /* SrcIsVolatile */ Memmove->isVolatile(),
+ /* DstIsVolatile */ Memmove->isVolatile(),
/* Context */ Context,
/* Function F */ F);
} else if (MemSetInst *Memset = dyn_cast<MemSetInst>(MemCall)) {
- convertMemSetToLoop(/* splitAt */ Memset,
- /* dstAddr */ Memset->getRawDest(),
- /* len */ Memset->getLength(),
- /* val */ Memset->getValue(),
+ convertMemSetToLoop(/* ConvertedInst */ Memset,
+ /* DstAddr */ Memset->getRawDest(),
+ /* CopyLen */ Memset->getLength(),
+ /* SetValue */ Memset->getValue(),
/* Context */ Context,
- /* F */ F);
+ /* Function F */ F);
}
MemCall->eraseFromParent();
}