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

[Michael Kruse via llvm-commits]

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@@ -4108,6 +4438,92 @@ OpenMPIRBuilder::createCanonicalLoop(const LocationDescription &Loc,
   return CL;
 }
 
+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) {
+  LocationDescription ComputeLoc =
+      ComputeIP.isSet() ? LocationDescription(ComputeIP, Loc.DL) : Loc;
+  updateToLocation(ComputeLoc);
+
+  Value *TripCount = calculateCanonicalLoopTripCount(
+      ComputeLoc, Start, Stop, Step, IsSigned, InclusiveStop, Name);
+  ScanInfo.Span = TripCount;
+  ScanInfo.OMPScanInit = splitBB(Builder, true, "scan.init");
+  Builder.SetInsertPoint(ScanInfo.OMPScanInit);
+
+  auto BodyGen = [=](InsertPointTy CodeGenIP, Value *IV) {
+    /// The control of the loopbody of following structure:
+    ///
+    ///     InputBlock
+    ///        |
+    ///     ContinueBlock
+    ///
+    ///  is transformed to:
+    ///
+    ///     InputBlock
+    ///        |
+    ///     OMPScanDispatch
+    ///
+    ///     OMPBeforeScanBlock
+    ///        |
+    ///     OMPScanLoopExit
+    ///        |
+    ///     ContinueBlock
+    ///
----------------
Meinersbur wrote:

Would be great as documentation of the ScanInformation type.

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