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[PGO] Memory intrinsic calls optimization based on profiled size

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This patch optimizes two memory intrinsic operations: memset and memcpy based
on the profiled size of the operation. The high level transformation is like:
  mem_op(..., size)
  ==>
  switch (size) {
    case s1:
       mem_op(..., s1);
       goto merge_bb;
    case s2:
       mem_op(..., s2);
       goto merge_bb;
    ...
    default:
       mem_op(..., size);
       goto merge_bb;
    }
  merge_bb:

Differential Revision: http://reviews.llvm.org/D28966

llvm-svn: 299446
This commit is contained in:
Rong Xu
2017-04-04 16:42:20 +00:00
parent e7cdcdea73
commit 48596b6f7a
14 changed files with 528 additions and 61 deletions
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30
llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
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@@ -1038,21 +1038,6 @@ void PGOUseFunc::populateCounters() {
DEBUG(FuncInfo.dumpInfo("after reading profile."));
}
static void setProfMetadata(Module *M, Instruction *TI,
ArrayRef<uint64_t> EdgeCounts, uint64_t MaxCount) {
MDBuilder MDB(M->getContext());
assert(MaxCount > 0 && "Bad max count");
uint64_t Scale = calculateCountScale(MaxCount);
SmallVector<unsigned, 4> Weights;
for (const auto &ECI : EdgeCounts)
Weights.push_back(scaleBranchCount(ECI, Scale));
DEBUG(dbgs() << "Weight is: ";
for (const auto &W : Weights) { dbgs() << W << " "; }
dbgs() << "\n";);
TI->setMetadata(llvm::LLVMContext::MD_prof, MDB.createBranchWeights(Weights));
}
// Assign the scaled count values to the BB with multiple out edges.
void PGOUseFunc::setBranchWeights() {
// Generate MD_prof metadata for every branch instruction.
@@ -1426,6 +1411,21 @@ bool PGOInstrumentationUseLegacyPass::runOnModule(Module &M) {
}
namespace llvm {
void setProfMetadata(Module *M, Instruction *TI, ArrayRef<uint64_t> EdgeCounts,
uint64_t MaxCount) {
MDBuilder MDB(M->getContext());
assert(MaxCount > 0 && "Bad max count");
uint64_t Scale = calculateCountScale(MaxCount);
SmallVector<unsigned, 4> Weights;
for (const auto &ECI : EdgeCounts)
Weights.push_back(scaleBranchCount(ECI, Scale));
DEBUG(dbgs() << "Weight is: ";
for (const auto &W : Weights) { dbgs() << W << " "; }
dbgs() << "\n";);
TI->setMetadata(llvm::LLVMContext::MD_prof, MDB.createBranchWeights(Weights));
}
template <> struct GraphTraits<PGOUseFunc *> {
typedef const BasicBlock *NodeRef;
typedef succ_const_iterator ChildIteratorType;