[Beignet] [PATCH] backend: Fix a bug in load-store optimization.
Ruiling Song
ruiling.song at intel.com
Fri Jul 21 06:46:41 UTC 2017
when we are merging STOREs, we should use the very last instruction
as the insertion point.
Signed-off-by: Ruiling Song <ruiling.song at intel.com>
---
backend/src/llvm/llvm_loadstore_optimization.cpp | 71 +++++++++++++++---------
1 file changed, 46 insertions(+), 25 deletions(-)
diff --git a/backend/src/llvm/llvm_loadstore_optimization.cpp b/backend/src/llvm/llvm_loadstore_optimization.cpp
index bb8dc5f..a1687c1 100644
--- a/backend/src/llvm/llvm_loadstore_optimization.cpp
+++ b/backend/src/llvm/llvm_loadstore_optimization.cpp
@@ -61,21 +61,24 @@ namespace gbe {
#endif
return optimizeLoadStore(BB);
}
- Type *getValueType(Value *insn);
- Value *getPointerOperand(Value *I);
+ Type *getValueType(Value *insn);
+ Value *getPointerOperand(Value *I);
unsigned getAddressSpace(Value *I);
- bool isSimpleLoadStore(Value *I);
- bool optimizeLoadStore(BasicBlock &BB);
-
- bool isLoadStoreCompatible(Value *A, Value *B, int *dist, int* elementSize, int maxVecSize);
- void mergeLoad(BasicBlock &BB, SmallVector<Instruction*, 16> &merged, Instruction *start,int offset);
- void mergeStore(BasicBlock &BB, SmallVector<Instruction*, 16> &merged, Instruction *start,int offset);
- bool findConsecutiveAccess(BasicBlock &BB,
- SmallVector<Instruction*, 16> &merged,
- const BasicBlock::iterator &start,
- unsigned maxVecSize,
- bool isLoad,
- int *addrOffset);
+ bool isSimpleLoadStore(Value *I);
+ bool optimizeLoadStore(BasicBlock &BB);
+
+ bool isLoadStoreCompatible(Value *A, Value *B, int *dist, int *elementSize,
+ int maxVecSize);
+ void mergeLoad(BasicBlock &BB, SmallVector<Instruction *, 16> &merged,
+ Instruction *first, int offset);
+ void mergeStore(BasicBlock &BB, SmallVector<Instruction *, 16> &merged,
+ Instruction *first, Instruction *last, int offset);
+ bool findConsecutiveAccess(BasicBlock &BB,
+ SmallVector<Instruction *, 16> &merged,
+ const BasicBlock::iterator &start,
+ unsigned maxVecSize, bool isLoad,
+ int *addrOffset, Instruction *&first,
+ Instruction *&last);
#if LLVM_VERSION_MAJOR * 10 + LLVM_VERSION_MINOR >= 40
virtual StringRef getPassName() const
#else
@@ -146,7 +149,7 @@ namespace gbe {
void GenLoadStoreOptimization::mergeLoad(BasicBlock &BB,
SmallVector<Instruction*, 16> &merged,
- Instruction *start,
+ Instruction *first,
int offset) {
IRBuilder<> Builder(&BB);
@@ -155,7 +158,7 @@ namespace gbe {
for(unsigned i = 0; i < size; i++) {
values.push_back(merged[i]);
}
- LoadInst *ld = cast<LoadInst>(start);
+ LoadInst *ld = cast<LoadInst>(first);
unsigned align = ld->getAlignment();
unsigned addrSpace = ld->getPointerAddressSpace();
// insert before first load
@@ -214,7 +217,9 @@ namespace gbe {
const BasicBlock::iterator &start,
unsigned maxVecSize,
bool isLoad,
- int *addrOffset) {
+ int *addrOffset,
+ Instruction *&first,
+ Instruction *&last) {
if(!isSimpleLoadStore(&*start)) return false;
unsigned targetAddrSpace = getAddressSpace(&*start);
@@ -233,6 +238,7 @@ namespace gbe {
int elementSize;
SmallVector<mergedInfo *, 32> searchInsnArray;
+ SmallVector<mergedInfo *, 32> orderedInstrs;
mergedInfo meInfoArray[32];
int indx = 0;
meInfoArray[indx++].init(&*start, 0);
@@ -275,13 +281,15 @@ namespace gbe {
if(indx > 1)
{
+ first = (*searchInsnArray.begin())->mInsn;
//try to sort the load/store by the offset from the start
//the farthest is at the beginning. this is easy to find the
//continuous load/store
+ orderedInstrs = searchInsnArray;
std::sort(searchInsnArray.begin(), searchInsnArray.end(), offsetSorter());
// try to find continuous loadstore insn in the candidate array
- for(unsigned i = 0; i < searchInsnArray.size(); i++)
+ for (unsigned i = 0; i < searchInsnArray.size(); i++)
{
unsigned j;
for(j = 0; j < maxVecSize-1 && (j+i+1) < searchInsnArray.size(); j++)
@@ -306,6 +314,17 @@ namespace gbe {
if (k >= maxVecSize)
break;
}
+ // find the last instruction if we are trying to merge STOREs.
+ // we will later use it as the insertion point.
+ if (!isLoad)
+ for (auto insn = orderedInstrs.rbegin();
+ insn != orderedInstrs.rend(); ++insn) {
+ if (std::find(merged.begin(), merged.end(), (*insn)->mInsn) !=
+ merged.end()) {
+ last = (*insn)->mInsn;
+ break;
+ }
+ }
break;
}
@@ -317,7 +336,8 @@ namespace gbe {
void GenLoadStoreOptimization::mergeStore(BasicBlock &BB,
SmallVector<Instruction*, 16> &merged,
- Instruction *start,
+ Instruction *first,
+ Instruction *last,
int offset) {
IRBuilder<> Builder(&BB);
@@ -326,7 +346,7 @@ namespace gbe {
for(unsigned i = 0; i < size; i++) {
values.push_back(cast<StoreInst>(merged[i])->getValueOperand());
}
- StoreInst *st = cast<StoreInst>(start);
+ StoreInst *st = cast<StoreInst>(first);
if(!st)
return;
@@ -334,7 +354,7 @@ namespace gbe {
unsigned align = st->getAlignment();
// insert before the last store
- Builder.SetInsertPoint(merged[size-1]);
+ Builder.SetInsertPoint(last);
Type *dataTy = st->getValueOperand()->getType();
VectorType *vecTy = VectorType::get(dataTy, size);
@@ -405,13 +425,14 @@ namespace gbe {
continue;
int addrOffset = 0;
+ Instruction *first = nullptr, *last = nullptr;
unsigned maxVecSize = (ty->isFloatTy() || ty->isIntegerTy(32)) ? 4 :
(ty->isIntegerTy(16) ? 8 : 16);
- bool reorder = findConsecutiveAccess(BB, merged, BBI, maxVecSize, isLoad, &addrOffset);
+ bool reorder = findConsecutiveAccess(BB, merged, BBI, maxVecSize,
+ isLoad, &addrOffset, first, last);
uint32_t size = merged.size();
uint32_t pos = 0;
bool doDeleting = size > 1;
- BasicBlock::iterator startLS = BBI;
if (doDeleting) {
// choose next undeleted instruction
BBI = findSafeInstruction(merged, BBI, reorder);
@@ -423,9 +444,9 @@ namespace gbe {
(size >= 4 ? 4 : size));
SmallVector<Instruction*, 16> mergedVec(merged.begin() + pos, merged.begin() + pos + vecSize);
if(isLoad)
- mergeLoad(BB, mergedVec, &*startLS, addrOffset);
+ mergeLoad(BB, mergedVec, first, addrOffset);
else
- mergeStore(BB, mergedVec, &*startLS, addrOffset);
+ mergeStore(BB, mergedVec, first, last, addrOffset);
// remove merged insn
for(uint32_t i = 0; i < mergedVec.size(); i++)
mergedVec[i]->eraseFromParent();
--
2.4.1
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