[llvm] [VPlan] Widen masked unit-stride consecutive accesses in VPlan. (PR #211315)

[Luke Lau via llvm-commits]

================
@@ -5423,6 +5421,24 @@ void VPlanTransforms::makeMemOpWideningDecisions(VPlan &Plan, VFRange &Range,
         if (getConstantStride(Ptr, ScalarTy, CostCtx.PSE, CostCtx.L) != 1)
           return false;
 
+        // A predicated access can only be widened (rather than scalarized) if
+        // the target supports a masked load/store for it.
----------------
lukel97 wrote:

In theory we could but I think the comment is referring to how VPWidenLoadRecipe will always create a `llvm.masked.load` for a unit-stride masked access.

https://github.com/llvm/llvm-project/pull/211315