[llvm] [LV]Initial support for safe distance in predicated DataWithEVL vectorization mode. (PR #102897)

[via llvm-commits]

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@@ -1337,7 +1337,23 @@ void VPlanTransforms::addActiveLaneMask(
 /// %NextEVLIV = add IVSize (cast i32 %VPEVVL to IVSize), %EVLPhi
 /// ...
 ///
-bool VPlanTransforms::tryAddExplicitVectorLength(VPlan &Plan) {
+/// If MaxEVLSafeElements is provided, the function adds the following recipes:
+/// vector.ph:
+/// ...
+///
+/// vector.body:
+/// ...
+/// %EVLPhi = EXPLICIT-VECTOR-LENGTH-BASED-IV-PHI [ %StartV, %vector.ph ],
+///                                               [ %NextEVLIV, %vector.body ]
+/// %cmp = cmp ult %EVLPhi, MaxEVLSafeElements
+/// %SAFE_AVL = select %cmp, %EVLPhi, MaxEVLSafeElements
+/// %VPEVL = EXPLICIT-VECTOR-LENGTH %SAFE_AVL, original TC
+/// ...
+/// %NextEVLIV = add IVSize (cast i32 %VPEVVL to IVSize), %EVLPhi
----------------
ayalz wrote:

```suggestion
/// %NextEVLIV = add IVSize (cast i32 %VPEVL to IVSize), %EVLPhi
```

https://github.com/llvm/llvm-project/pull/102897