[llvm] [RISCV] Convert mask to scalable vector in lowerVPREDUCE. (PR #228219)

[Craig Topper via llvm-commits]

https://github.com/topperc created https://github.com/llvm/llvm-project/pull/228219

None

>From 6eafe4c3dfaff67ce477aec796dd7c808eca1f69 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Thu, 1 Oct 2026 12:43:17 -0700
Subject: [PATCH] [RISCV] Convert mask to scalable vector in lowerVPREDUCE.

---
 llvm/lib/Target/RISCV/RISCVISelLowering.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 5c2cb79379dfa..47e2ca7307d50 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -14278,13 +14278,14 @@ SDValue RISCVTargetLowering::lowerVPREDUCE(SDValue Op,
   MVT VecVT = VecEVT.getSimpleVT();
   unsigned RVVOpcode = getRVVReductionOp(Opc);
 
+  SDValue VL = Op.getOperand(3);
+  SDValue Mask = Op.getOperand(2);
   if (VecVT.isFixedLengthVector()) {
     auto ContainerVT = getContainerForFixedLengthVector(VecVT);
     Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
+    Mask = convertToScalableVector(getMaskTypeFor(ContainerVT), Mask, DAG,
+                                   Subtarget);
   }
-
-  SDValue VL = Op.getOperand(3);
-  SDValue Mask = Op.getOperand(2);
   SDValue Res =
       lowerReductionSeq(RVVOpcode, Op.getSimpleValueType(), Op.getOperand(0),
                         Vec, Mask, VL, DL, DAG, Subtarget);