[llvm] [OpenMP] [IR Builder] Changes to Support Scan Operation (PR #136035)

[Anchu Rajendran S via llvm-commits]

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@@ -4118,6 +4455,76 @@ OpenMPIRBuilder::createCanonicalLoop(const LocationDescription &Loc,
   return CL;
 }
 
+Expected<ScanInfo *> OpenMPIRBuilder::scanInfoInitialize() {
+  ScanInfos.emplace_front();
+  ScanInfo *Result = &ScanInfos.front();
+  return Result;
+}
+
+Expected<SmallVector<llvm::CanonicalLoopInfo *>>
+OpenMPIRBuilder::createCanonicalScanLoops(
+    const LocationDescription &Loc, LoopBodyGenCallbackTy BodyGenCB,
+    Value *Start, Value *Stop, Value *Step, bool IsSigned, bool InclusiveStop,
+    InsertPointTy ComputeIP, const Twine &Name, ScanInfo *ScanRedInfo) {
+  LocationDescription ComputeLoc =
+      ComputeIP.isSet() ? LocationDescription(ComputeIP, Loc.DL) : Loc;
+  updateToLocation(ComputeLoc);
+
+  SmallVector<CanonicalLoopInfo *> Result;
+
+  Value *TripCount = calculateCanonicalLoopTripCount(
+      ComputeLoc, Start, Stop, Step, IsSigned, InclusiveStop, Name);
+  ScanRedInfo->Span = TripCount;
+  ScanRedInfo->OMPScanInit = splitBB(Builder, true, "scan.init");
+  Builder.SetInsertPoint(ScanRedInfo->OMPScanInit);
+
+  auto BodyGen = [=](InsertPointTy CodeGenIP, Value *IV) {
+    Builder.restoreIP(CodeGenIP);
+    ScanRedInfo->IV = IV;
+    createScanBBs(ScanRedInfo);
+    BasicBlock *InputBlock = Builder.GetInsertBlock();
+    Instruction *Terminator = InputBlock->getTerminator();
+    assert(Terminator->getNumSuccessors() == 1);
+    BasicBlock *ContinueBlock = Terminator->getSuccessor(0);
+    Terminator->setSuccessor(0, ScanRedInfo->OMPScanDispatch);
+    emitBlock(ScanRedInfo->OMPBeforeScanBlock,
+              Builder.GetInsertBlock()->getParent());
+    Builder.CreateBr(ScanRedInfo->OMPScanLoopExit);
+    emitBlock(ScanRedInfo->OMPScanLoopExit,
+              Builder.GetInsertBlock()->getParent());
+    Builder.CreateBr(ContinueBlock);
+    Builder.SetInsertPoint(
+        ScanRedInfo->OMPBeforeScanBlock->getFirstInsertionPt());
+    return BodyGenCB(Builder.saveIP(), IV);
+  };
+
+  const auto &&InputLoopGen = [&]() -> Error {
+    auto LoopInfo = createCanonicalLoop(Builder.saveIP(), BodyGen, Start, Stop,
----------------
anchuraj wrote:

Updated.

https://github.com/llvm/llvm-project/pull/136035