[IVDescriptors] Change opcode of FindLast/FindFirst recurrence to Instruction::Select

Author: Mel-Chen

llvm/lib/Analysis/IVDescriptors.cpp

@@ -1226,10 +1226,6 @@ unsigned RecurrenceDescriptor::getOpcode(RecurKind Kind) {
   case RecurKind::Mul:
     return Instruction::Mul;
   case RecurKind::AnyOf:
-  case RecurKind::FindFirstIVSMin:
-  case RecurKind::FindFirstIVUMin:
-  case RecurKind::FindLastIVSMax:
-  case RecurKind::FindLastIVUMax:
   case RecurKind::Or:
     return Instruction::Or;
   case RecurKind::And:
@@ -1253,6 +1249,11 @@ unsigned RecurrenceDescriptor::getOpcode(RecurKind Kind) {
   case RecurKind::FMaximumNum:
   case RecurKind::FMinimumNum:
     return Instruction::FCmp;
+  case RecurKind::FindFirstIVSMin:
+  case RecurKind::FindFirstIVUMin:
+  case RecurKind::FindLastIVSMax:
+  case RecurKind::FindLastIVUMax:
+    return Instruction::Select;
   default:
     llvm_unreachable("Unknown recurrence operation");
   }

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -6515,9 +6515,14 @@ void LoopVectorizationCostModel::collectInLoopReductions() {
     if (RdxDesc.getRecurrenceType() != Phi->getType())
       continue;
 
+    // In-loop AnyOf and FindIV reductions are not yet supported.
+    RecurKind Kind = RdxDesc.getRecurrenceKind();
+    if (RecurrenceDescriptor::isAnyOfRecurrenceKind(Kind) ||
+        RecurrenceDescriptor::isFindIVRecurrenceKind(Kind))
+      continue;
+
     // If the target would prefer this reduction to happen "in-loop", then we
     // want to record it as such.
-    RecurKind Kind = RdxDesc.getRecurrenceKind();
     if (!PreferInLoopReductions && !useOrderedReductions(RdxDesc) &&
         !TTI.preferInLoopReduction(Kind, Phi->getType()))
       continue;