[llvm] [LV] Add support for cmp reductions with decreasing IVs. (PR #140451)

[Ramkumar Ramachandra via llvm-commits]

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@@ -1244,12 +1244,16 @@ Value *llvm::createAnyOfReduction(IRBuilderBase &Builder, Value *Src,
 Value *llvm::createFindLastIVReduction(IRBuilderBase &Builder, Value *Src,
                                        Value *Start,
                                        const RecurrenceDescriptor &Desc) {
-  assert(RecurrenceDescriptor::isFindLastIVRecurrenceKind(
-             Desc.getRecurrenceKind()) &&
-         "Unexpected reduction kind");
+  assert(
+      RecurrenceDescriptor::isFindIVRecurrenceKind(Desc.getRecurrenceKind()) &&
+      "Unexpected reduction kind");
   Value *Sentinel = Desc.getSentinelValue();
   Value *MaxRdx = Src->getType()->isVectorTy()
-                      ? Builder.CreateIntMaxReduce(Src, true)
+                      ? (Desc.getRecurrenceKind() == RecurKind::FindLastIV
+                             ? Builder.CreateIntMaxReduce(Src, true)
+                             : Builder.CreateIntMinReduce(
+                                   Src, Desc.getRecurrenceKind() ==
+                                            RecurKind::FindFirstIVSMin))
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artagnon wrote:

This ternary expression reads badly?

https://github.com/llvm/llvm-project/pull/140451