[llvm] [LoopVectorizer] Allow partial reductions to be made in predicated loops (PR #124268)

[James Chesterman via llvm-commits]

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@@ -2448,7 +2448,8 @@ class VPReductionPHIRecipe : public VPHeaderPHIRecipe,
 /// A recipe for forming partial reductions. In the loop, an accumulator and
 /// vector operand are added together and passed to the next iteration as the
 /// next accumulator. After the loop body, the accumulator is reduced to a
-/// scalar value.
+/// scalar value. If the mask operand is not nullptr then it is applied to the
+/// vector operand on each iteration.
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JamesChesterman wrote:

Done

https://github.com/llvm/llvm-project/pull/124268